A feed for improving reproductive and growth performance

Abstract

The present application belongs to the field of agriculture and animal husbandry, and particularly relates to a feed formula for improving the breeding performance and growth performance of mammals under stress conditions. The present application effectively alleviates the adverse effects of heat stress on does by adding proline (Pro) in the basic feed, and can improve the breeding performance of does and promote the growth of kits, thereby achieving the improvement of economic benefits of breeding and providing an effective nutritional regulation strategy for summer rabbit breeding. Proline is easy to obtain and simple to operate, and is suitable for mass production. Moreover, as an additive, proline has high safety, is directly added to the feed of pregnant mammals, is easy to operate, does not need to be injected or implanted, and avoids the generation of other stress reactions of mammals.

Description

Technical Field

[0001] This invention belongs to the field of agriculture and animal husbandry, and specifically relates to a feed formula that improves the reproductive and growth performance of mammals under stress conditions. Background Technology

[0002] Rabbits are warm-blooded animals with thick fur and underdeveloped sweat glands, making them poorly heat-tolerant. Furthermore, with the increasing trend of global warming, improper husbandry and management can easily lead to heat stress in rabbits under high temperatures. The main cause of heat stress in rabbits is excessively high temperatures inside the rabbitry. The main reasons for increased ambient temperature in rabbit hutches are as follows: ① High outside temperatures allow heat to enter the hutch through doors, windows, walls, and the roof, causing a rise in internal temperature; ② The heat generated by the rabbits themselves, through respiration and body surface dissipation. Higher stocking densities result in more heat production and higher hutch temperatures; ③ Heat generated from the fermentation and decomposition of livestock waste. Livestock waste contains a large amount of organic matter and high moisture content. If not cleaned up promptly, it ferments and decomposes through microorganisms, generating heat and exhaust gases. The more waste accumulates and the longer it remains, the more heat is generated, leading to higher hutch temperatures and more exhaust gases, easily causing respiratory and other diseases.

[0003] In hot and humid environments, when the thermo-metabolic balance of livestock and poultry is disrupted, heat stress is easily triggered. Compared with other livestock such as cattle and pigs, rabbits, due to their dense fur, degenerated sweat glands (only a small amount distributed around the lips and groin), and reliance on respiration for heat dissipation, are more sensitive to heat stress. Heat stress not only inhibits feed intake in rabbits but also has a significant negative impact on their overall reproductive performance. Before mating / early pregnancy, it inhibits the pulsatile secretion of hypothalamic gonadotropin-releasing hormone (GnRH), reduces the release of pituitary luteinizing hormone (LH) and follicle-stimulating hormone (FSH), leading to impaired follicle development, decreased ovulation rate, luteal insufficiency, and insufficient progesterone secretion. At the same time, the ovaries also experience increased stress due to local oxidation, resulting in decreased oocyte quality, reduced fertilization rate, and lower embryo survival rate. In the mid-to-late stages of pregnancy, high temperatures reduce uteroplacental blood flow through blood redistribution, damage placental structure and function, and cause insufficient oxygen and nutrient supply to the fetus, ultimately manifesting as restricted fetal growth and development and increased embryonic mortality. In addition, under extreme high temperatures, female rabbits may experience heat-induced panting accompanied by drooling. When their body temperature rises above 41°C, they may develop neurological disorders (convulsions, coma), leading to miscarriage in the mid-to-late stages of pregnancy or perinatal death.

[0004] In intensive farming during the high-temperature season, overcoming the inhibitory effect of heat stress on the reproductive performance of female rabbits has become a key technological challenge for the industry. Traditional cooling management methods have drawbacks such as high equipment investment (increasing cooling costs by 40-60 yuan per square meter) and poor maintenance effect (the temperature in the shed only decreases by 2-3℃), making it difficult to meet the needs of large-scale production and thus difficult to promote.

[0005] Natural antioxidants (extracts from traditional Chinese medicine, amino acids, and other nutrients) are also effective means of alleviating heat stress. However, due to limitations in purification technology, many natural antioxidants have complex compositions in their extracts, making it difficult to guarantee feed safety and thus hindering their large-scale use in production. Proline (Pro, hydrogenated pyrrolidine), a cyclic imine, has long been known as a non-essential amino acid (NEAA), but with in-depth research, new directions have been explored.

[0006] Therefore, seeking a new, safe, and effective nutritional intervention program is of urgent practical significance. Summary of the Invention

[0007] This invention discovers that proline significantly improves the reproductive performance and offspring growth performance of mammals under heat stress conditions, and based on this, the invention was completed.

[0008] In a first aspect, the present invention provides a feed for improving the reproductive performance of mammals under heat stress conditions, the feed comprising proline and a complete diet; the proline content in the feed is selected from 1.63%-3.13%; the alanine content is selected from 0-1.16% to balance the total nitrogen content among the groups; the complete diet comprises corn, wheat middlings, corn bran, wheat bran, soybean oil, soybean meal, rapeseed meal, distillers' grains, corn germ meal, artemisia annua powder, rice husk powder, peanut shell powder, white stalk powder, alkali grass, and premix.

[0009] Furthermore, the mammal in question is a mammal subjected to stress.

[0010] Furthermore, the stress condition is heat stress.

[0011] Furthermore, the mammals include mice, rats, pigs, cattle, sheep, horses, deer, foxes, mink, and rabbits.

[0012] Furthermore, the reproductive performance includes conception rate, farrowing rate, litter size, number of live offspring in a litter, number of stillbirths, total litter size, total number of live offspring in a litter, number of stillbirths in a litter, total weight of litter at birth, weight of litter with live offspring at birth, placental efficiency, total number of litters, number of live offspring in a litter, number of stillbirths in a litter, total litter weight, weight of live offspring in a litter, average weight of live offspring, placental weight in a litter, and average weight of live offspring at birth.

[0013] Preferably, the reproductive performance includes litter size, litter size, total litter size, total litter size, litter size, litter size, litter size, litter size, total litter size, total litter size, total litter size, litter size, litter size, placental weight, and litter size of live offspring.

[0014] Furthermore, the proline content is 1.63%.

[0015] Furthermore, the proline includes basal feed proline and exogenous proline; the amount of exogenous proline added is 0.5%.

[0016] Furthermore, the alanine content is 1.16%.

[0017] Furthermore, the number of parts of corn is selected from 10-15 parts.

[0018] Furthermore, the corn portion is 13 parts.

[0019] Furthermore, the amount of the secondary flour is selected from 3 to 7 parts.

[0020] Furthermore, the amount of the secondary flour is 5 parts.

[0021] Furthermore, the number of parts of corn husk is selected from 3 to 7 parts.

[0022] Furthermore, the corn husks are in portions of 5.

[0023] Furthermore, the amount of wheat bran is selected from 5 to 10 parts.

[0024] Furthermore, the wheat bran is present in 8 parts.

[0025] Furthermore, the amount of soybean oil is selected from 0.5 to 2.5 parts.

[0026] Furthermore, the soybean oil is present in 1.5 parts.

[0027] Furthermore, the soybean meal is selected from 10-20 parts.

[0028] Furthermore, the soybean meal is in portions of 15.

[0029] Furthermore, the amount of rapeseed meal is selected from 3 to 9 parts.

[0030] Furthermore, the rapeseed meal comprises 6 parts.

[0031] Furthermore, the amount of the lees is selected from 6 to 12 parts.

[0032] Furthermore, the amount of the lees is 9 parts.

[0033] Furthermore, the number of parts of the corn germ meal is selected from 5 to 8 parts.

[0034] Furthermore, the corn germ meal comprises 6.5 parts.

[0035] Furthermore, the amount of artemisia powder is selected from 0.5 to 2.5 parts.

[0036] Furthermore, the amount of artemisia powder is 1.5 parts.

[0037] Furthermore, the amount of rice husk powder is selected from 3 to 9 parts.

[0038] Furthermore, the rice husk powder comprises 6 parts.

[0039] Furthermore, the amount of peanut shell powder is selected from 3 to 7 parts.

[0040] Furthermore, the peanut shell powder is in the form of 5 parts.

[0041] Furthermore, the amount of white stalk powder is selected from 5-10 parts.

[0042] Furthermore, the amount of white stalk powder is 7 parts.

[0043] Furthermore, the amount of alkali grass is selected from 5-10 parts.

[0044] Furthermore, the amount of alkali grass is 8 parts.

[0045] Furthermore, the premixed material is in the form of 5 parts.

[0046] Furthermore, the premix includes iron (Fe), copper (Cu), zinc (Zn), manganese (Mn), cobalt (Co), iodine (I), selenium (Se), vanadium (VA), vitamin D, vitamin E, vitamin K, vitamin B1, vitamin B2, vitamin B5, vitamin B6, and vitamin B1. 12 Vitamins B3, B9, B4, and B7.

[0047] Furthermore, the Fe content is selected from 50-100 mg / kg.

[0048] Preferably, the Fe content is 70 mg / kg.

[0049] Furthermore, the Cu content is selected from 10-30 mg / kg.

[0050] Preferably, the Cu content is 20 mg / kg.

[0051] Furthermore, the Zn content is selected from 50-100 mg / kg.

[0052] Preferably, the Zn content is 70 mg / kg.

[0053] Furthermore, the content of Mn is selected from 5-15 mg / kg.

[0054] Preferably, the Mn content is 10 mg / kg.

[0055] Furthermore, the content of Co is selected from 0.1-0.2 mg / kg.

[0056] Preferably, the content of Co is 0.15 mg / kg.

[0057] Furthermore, the content of I is selected from 0.1-0.3 mg / kg.

[0058] Preferably, the content of I is 0.2 mg / kg.

[0059] Furthermore, the content of Se is selected from 0.2-0.3 mg / kg.

[0060] Preferably, the content of Se is 0.25 mg / kg.

[0061] Furthermore, the vitamin A content is selected from 9000-11000 IU / kg.

[0062] Preferably, the vitamin A content is 10000 IU / kg.

[0063] Furthermore, the vitamin D content is selected from 800-1000 IU / kg.

[0064] Preferably, the vitamin D content is 900 IU / kg.

[0065] Furthermore, the vitamin E content is selected from 30-70 mg / kg.

[0066] Preferably, the vitamin E content is 50 mg / kg.

[0067] Furthermore, the vitamin K content is selected from 1-3 mg / kg.

[0068] Preferably, the vitamin K content is 2 mg / kg.

[0069] Furthermore, the vitamin B1 content is selected from 1-3 mg / kg.

[0070] Preferably, the vitamin B1 content is 2 mg / kg.

[0071] Furthermore, the vitamin B2 content is selected from 4-8 mg / kg.

[0072] Preferably, the vitamin B2 content is 6 mg / kg.

[0073] Furthermore, the vitamin B5 content is selected from 30-70 mg / kg.

[0074] Preferably, the vitamin B5 content is 50 mg / kg.

[0075] Furthermore, the vitamin B6 content is selected from 1-3 mg / kg.

[0076] Preferably, the vitamin B6 content is 2 mg / kg.

[0077] Furthermore, the vitamin B... 12 The content is selected from 0.01-0.03 mg / kg.

[0078] Preferably, the vitamin B 12 The content is 0.02 mg / kg.

[0079] Furthermore, the vitamin B3 content is selected from 30-70 mg / kg.

[0080] Preferably, the vitamin B3 content is 50 mg / kg.

[0081] Furthermore, the vitamin B9 content is selected from 30-60 mg / kg.

[0082] Preferably, the vitamin B9 content is 44 mg / kg.

[0083] Furthermore, the vitamin B4 content is selected from 900-1100 mg / kg.

[0084] Preferably, the vitamin B4 content is 1000 mg / kg.

[0085] Furthermore, the content of vitamin B7 is selected from 0.1-0.3 mg / kg.

[0086] Preferably, the vitamin B7 content is 0.2 mg / kg.

[0087] In one embodiment of the present invention, proline is added directly to the feed of pregnant mammals, which is convenient to operate and does not require injection or implantation, thus avoiding stress response in animals.

[0088] Secondly, the present invention provides the use of the feed as described in the first aspect of the present invention in the preparation of products that improve the reproductive performance of mammals.

[0089] Furthermore, the mammal in question is a mammal subjected to stress.

[0090] Furthermore, the stress condition is heat stress.

[0091] Furthermore, the mammals include mice, rats, pigs, cattle, sheep, horses, deer, foxes, mink, and rabbits.

[0092] Furthermore, the reproductive performance includes conception rate, farrowing rate, litter size, number of live offspring in a litter, number of stillbirths, total litter size, total number of live offspring in a litter, number of stillbirths in a litter, total weight of litter at birth, weight of litter with live offspring at birth, placental efficiency, total number of litters, number of live offspring in a litter, number of stillbirths in a litter, total litter weight, weight of live offspring in a litter, average weight of live offspring, placental weight in a litter, and average weight of live offspring at birth.

[0093] Preferably, the reproductive performance includes litter size, litter size, total litter size, total litter size, litter size, litter size, litter size, litter size, total litter size, total litter size, total litter size, litter size, litter size, placental weight, and litter size of live offspring.

[0094] Furthermore, the proline content is 1.63%.

[0095] Furthermore, the proline includes basal feed proline and exogenous proline; the amount of exogenous proline added is 0.5%.

[0096] Furthermore, the alanine content is 1.16%.

[0097] Furthermore, the number of parts of corn is selected from 10-15 parts.

[0098] Furthermore, the corn portion is 13 parts.

[0099] Furthermore, the amount of the secondary flour is selected from 3 to 7 parts.

[0100] Furthermore, the amount of the secondary flour is 5 parts.

[0101] Furthermore, the number of parts of corn husk is selected from 3 to 7 parts.

[0102] Furthermore, the corn husks are in portions of 5.

[0103] Furthermore, the amount of wheat bran is selected from 5 to 10 parts.

[0104] Furthermore, the wheat bran is present in 8 parts.

[0105] Furthermore, the amount of soybean oil is selected from 0.5 to 2.5 parts.

[0106] Furthermore, the soybean oil is present in 1.5 parts.

[0107] Furthermore, the soybean meal is selected from 10-20 parts.

[0108] Furthermore, the soybean meal is in portions of 15.

[0109] Furthermore, the amount of rapeseed meal is selected from 3 to 9 parts.

[0110] Furthermore, the rapeseed meal comprises 6 parts.

[0111] Furthermore, the amount of the lees is selected from 6 to 12 parts.

[0112] Furthermore, the amount of the lees is 9 parts.

[0113] Furthermore, the number of parts of the corn germ meal is selected from 5 to 8 parts.

[0114] Furthermore, the corn germ meal comprises 6.5 parts.

[0115] Furthermore, the amount of artemisia powder is selected from 0.5 to 2.5 parts.

[0116] Furthermore, the amount of artemisia powder is 1.5 parts.

[0117] Furthermore, the amount of rice husk powder is selected from 3 to 9 parts.

[0118] Furthermore, the rice husk powder comprises 6 parts.

[0119] Furthermore, the amount of peanut shell powder is selected from 3 to 7 parts.

[0120] Furthermore, the peanut shell powder is in the form of 5 parts.

[0121] Furthermore, the amount of white stalk powder is selected from 5-10 parts.

[0122] Furthermore, the amount of white stalk powder is 7 parts.

[0123] Furthermore, the amount of alkali grass is selected from 5-10 parts.

[0124] Furthermore, the amount of alkali grass is 8 parts.

[0125] Furthermore, the premixed material is in the form of 5 parts.

[0126] Furthermore, the premix includes iron (Fe), copper (Cu), zinc (Zn), manganese (Mn), cobalt (Co), iodine (I), selenium (Se), vanadium (VA), vitamin D, vitamin E, vitamin K, vitamin B1, vitamin B2, vitamin B5, vitamin B6, and vitamin B1. 12 Vitamins B3, B9, B4, and B7.

[0127] Furthermore, the Fe content is selected from 50-100 mg / kg.

[0128] Preferably, the Fe content is 70 mg / kg.

[0129] Furthermore, the Cu content is selected from 10-30 mg / kg.

[0130] Preferably, the Cu content is 20 mg / kg.

[0131] Furthermore, the Zn content is selected from 50-100 mg / kg.

[0132] Preferably, the Zn content is 70 mg / kg.

[0133] Furthermore, the content of Mn is selected from 5-15 mg / kg.

[0134] Preferably, the Mn content is 10 mg / kg.

[0135] Furthermore, the content of Co is selected from 0.1-0.2 mg / kg.

[0136] Preferably, the content of Co is 0.15 mg / kg.

[0137] Furthermore, the content of I is selected from 0.1-0.3 mg / kg.

[0138] Preferably, the content of I is 0.2 mg / kg.

[0139] Furthermore, the content of Se is selected from 0.2-0.3 mg / kg.

[0140] Preferably, the content of Se is 0.25 mg / kg.

[0141] Furthermore, the vitamin A content is selected from 9000-11000 IU / kg.

[0142] Preferably, the vitamin A content is 10000 IU / kg.

[0143] Furthermore, the vitamin D content is selected from 800-1000 IU / kg.

[0144] Preferably, the vitamin D content is 900 IU / kg.

[0145] Furthermore, the vitamin E content is selected from 30-70 mg / kg.

[0146] Preferably, the vitamin E content is 50 mg / kg.

[0147] Furthermore, the vitamin K content is selected from 1-3 mg / kg.

[0148] Preferably, the vitamin K content is 2 mg / kg.

[0149] Furthermore, the vitamin B1 content is selected from 1-3 mg / kg.

[0150] Preferably, the vitamin B1 content is 2 mg / kg.

[0151] Furthermore, the vitamin B2 content is selected from 4-8 mg / kg.

[0152] Preferably, the vitamin B2 content is 6 mg / kg.

[0153] Furthermore, the vitamin B5 content is selected from 30-70 mg / kg.

[0154] Preferably, the vitamin B5 content is 50 mg / kg.

[0155] Furthermore, the vitamin B6 content is selected from 1-3 mg / kg.

[0156] Preferably, the vitamin B6 content is 2 mg / kg.

[0157] Furthermore, the vitamin B... 12 The content is selected from 0.01-0.03 mg / kg.

[0158] Preferably, the vitamin B 12 The content is 0.02 mg / kg.

[0159] Furthermore, the vitamin B3 content is selected from 30-70 mg / kg.

[0160] Preferably, the vitamin B3 content is 50 mg / kg.

[0161] Furthermore, the vitamin B9 content is selected from 30-60 mg / kg.

[0162] Preferably, the vitamin B9 content is 44 mg / kg.

[0163] Furthermore, the vitamin B4 content is selected from 900-1100 mg / kg.

[0164] Preferably, the vitamin B4 content is 1000 mg / kg.

[0165] Furthermore, the content of vitamin B7 is selected from 0.1-0.3 mg / kg.

[0166] Preferably, the vitamin B7 content is 0.2 mg / kg.

[0167] In one embodiment of the present invention, proline is added directly to the feed of pregnant mammals, which is convenient to operate and does not require injection or implantation, thus avoiding stress response in animals.

[0168] Thirdly, the present invention provides a feed for improving the growth performance of mammalian offspring under heat stress conditions, the feed comprising proline and a complete diet; the proline content in the feed is selected from 1.63%-3.13%; the alanine content is selected from 0-1.16% to balance the total nitrogen content among the groups; the complete diet includes corn, wheat middlings, corn bran, wheat bran, soybean oil, soybean meal, rapeseed meal, distillers' grains, corn germ meal, artemisia annua powder, rice husk powder, peanut shell powder, white stalk powder, alkali grass, and premix.

[0169] Furthermore, the mammal in question is a mammal subjected to stress.

[0170] Furthermore, the stress condition is heat stress.

[0171] Furthermore, the mammals include mice, rats, pigs, cattle, sheep, horses, deer, foxes, mink, and rabbits.

[0172] Furthermore, the growth performance includes the number of litters of rabbits, the litter weight of the rabbits, and the average weight of the rabbits per litter.

[0173] Furthermore, the proline content is 1.63%.

[0174] Furthermore, the proline includes basal feed proline and exogenous proline; the amount of exogenous proline added is 0.5%.

[0175] Furthermore, the alanine content is 1.16%.

[0176] Furthermore, the number of parts of corn is selected from 10-15 parts.

[0177] Furthermore, the corn portion is 13 parts.

[0178] Furthermore, the amount of the secondary flour is selected from 3 to 7 parts.

[0179] Furthermore, the amount of the secondary flour is 5 parts.

[0180] Furthermore, the number of parts of corn husk is selected from 3 to 7 parts.

[0181] Furthermore, the corn husks are in portions of 5.

[0182] Furthermore, the amount of wheat bran is selected from 5 to 10 parts.

[0183] Furthermore, the wheat bran is present in 8 parts.

[0184] Furthermore, the amount of soybean oil is selected from 0.5 to 2.5 parts.

[0185] Furthermore, the soybean oil is present in 1.5 parts.

[0186] Furthermore, the soybean meal is selected from 10-20 parts.

[0187] Furthermore, the soybean meal is in portions of 15.

[0188] Furthermore, the amount of rapeseed meal is selected from 3 to 9 parts.

[0189] Furthermore, the rapeseed meal comprises 6 parts.

[0190] Furthermore, the amount of the lees is selected from 6 to 12 parts.

[0191] Furthermore, the amount of the lees is 9 parts.

[0192] Furthermore, the number of parts of the corn germ meal is selected from 5 to 8 parts.

[0193] Furthermore, the corn germ meal comprises 6.5 parts.

[0194] Furthermore, the amount of artemisia powder is selected from 0.5 to 2.5 parts.

[0195] Furthermore, the amount of artemisia powder is 1.5 parts.

[0196] Furthermore, the amount of rice husk powder is selected from 3 to 9 parts.

[0197] Furthermore, the rice husk powder comprises 6 parts.

[0198] Furthermore, the amount of peanut shell powder is selected from 3 to 7 parts.

[0199] Furthermore, the peanut shell powder is in the form of 5 parts.

[0200] Furthermore, the amount of white stalk powder is selected from 5-10 parts.

[0201] Furthermore, the amount of white stalk powder is 7 parts.

[0202] Furthermore, the amount of alkali grass is selected from 5-10 parts.

[0203] Furthermore, the amount of alkali grass is 8 parts.

[0204] Furthermore, the premixed material is in the form of 5 parts.

[0205] Furthermore, the premix includes iron (Fe), copper (Cu), zinc (Zn), manganese (Mn), cobalt (Co), iodine (I), selenium (Se), vanadium (VA), vitamin D, vitamin E, vitamin K, vitamin B1, vitamin B2, vitamin B5, vitamin B6, and vitamin B1. 12 Vitamins B3, B9, B4, and B7.

[0206] Furthermore, the Fe content is selected from 50-100 mg / kg.

[0207] Preferably, the Fe content is 70 mg / kg.

[0208] Furthermore, the Cu content is selected from 10-30 mg / kg.

[0209] Preferably, the Cu content is 20 mg / kg.

[0210] Furthermore, the Zn content is selected from 50-100 mg / kg.

[0211] Preferably, the Zn content is 70 mg / kg.

[0212] Furthermore, the content of Mn is selected from 5-15 mg / kg.

[0213] Preferably, the Mn content is 10 mg / kg.

[0214] Furthermore, the content of Co is selected from 0.1-0.2 mg / kg.

[0215] Preferably, the content of Co is 0.15 mg / kg.

[0216] Furthermore, the content of I is selected from 0.1-0.3 mg / kg.

[0217] Preferably, the content of I is 0.2 mg / kg.

[0218] Furthermore, the content of Se is selected from 0.2-0.3 mg / kg.

[0219] Preferably, the content of Se is 0.25 mg / kg.

[0220] Furthermore, the vitamin A content is selected from 9000-11000 IU / kg.

[0221] Preferably, the vitamin A content is 10000 IU / kg.

[0222] Furthermore, the vitamin D content is selected from 800-1000 IU / kg.

[0223] Preferably, the vitamin D content is 900 IU / kg.

[0224] Furthermore, the vitamin E content is selected from 30-70 mg / kg.

[0225] Preferably, the vitamin E content is 50 mg / kg.

[0226] Furthermore, the vitamin K content is selected from 1-3 mg / kg.

[0227] Preferably, the vitamin K content is 2 mg / kg.

[0228] Furthermore, the vitamin B1 content is selected from 1-3 mg / kg.

[0229] Preferably, the vitamin B1 content is 2 mg / kg.

[0230] Furthermore, the vitamin B2 content is selected from 4-8 mg / kg.

[0231] Preferably, the vitamin B2 content is 6 mg / kg.

[0232] Furthermore, the vitamin B5 content is selected from 30-70 mg / kg.

[0233] Preferably, the vitamin B5 content is 50 mg / kg.

[0234] Furthermore, the vitamin B6 content is selected from 1-3 mg / kg.

[0235] Preferably, the vitamin B6 content is 2 mg / kg.

[0236] Furthermore, the vitamin B... 12 The content is selected from 0.01-0.03 mg / kg.

[0237] Preferably, the vitamin B 12 The content is 0.02 mg / kg.

[0238] Furthermore, the vitamin B3 content is selected from 30-70 mg / kg.

[0239] Preferably, the vitamin B3 content is 50 mg / kg.

[0240] Furthermore, the vitamin B9 content is selected from 30-60 mg / kg.

[0241] Preferably, the vitamin B9 content is 44 mg / kg.

[0242] Furthermore, the vitamin B4 content is selected from 900-1100 mg / kg.

[0243] Preferably, the vitamin B4 content is 1000 mg / kg.

[0244] Furthermore, the content of vitamin B7 is selected from 0.1-0.3 mg / kg.

[0245] Preferably, the vitamin B7 content is 0.2 mg / kg.

[0246] In one embodiment of the present invention, proline is added directly to the feed of pregnant mammals, which is convenient to operate and does not require injection or implantation, thus avoiding stress response in animals.

[0247] Fourthly, the present invention provides the use of the feed as described in the third aspect of the present invention in the preparation of products that improve the growth performance of mammalian offspring.

[0248] Furthermore, the mammal in question is a mammal subjected to stress.

[0249] Furthermore, the stress condition is heat stress.

[0250] Furthermore, the mammals include mice, rats, pigs, cattle, sheep, horses, deer, foxes, mink, and rabbits.

[0251] Furthermore, the growth performance includes the average number of kits per litter, the litter weight of kits, and the average weight of kits per litter.

[0252] Furthermore, the proline content is 1.63%.

[0253] Furthermore, the proline includes basal feed proline and exogenous proline; the amount of exogenous proline added is 0.5%.

[0254] Furthermore, the alanine content is 1.16%.

[0255] Furthermore, the number of parts of corn is selected from 10-15 parts.

[0256] Furthermore, the corn portion is 13 parts.

[0257] Furthermore, the amount of the secondary flour is selected from 3 to 7 parts.

[0258] Furthermore, the amount of the secondary flour is 5 parts.

[0259] Furthermore, the number of parts of corn husk is selected from 3 to 7 parts.

[0260] Furthermore, the corn husks are in portions of 5.

[0261] Furthermore, the amount of wheat bran is selected from 5 to 10 parts.

[0262] Furthermore, the wheat bran is present in 8 parts.

[0263] Furthermore, the amount of soybean oil is selected from 0.5 to 2.5 parts.

[0264] Furthermore, the soybean oil is present in 1.5 parts.

[0265] Furthermore, the soybean meal is selected from 10-20 parts.

[0266] Furthermore, the soybean meal is in portions of 15.

[0267] Furthermore, the amount of rapeseed meal is selected from 3 to 9 parts.

[0268] Furthermore, the rapeseed meal comprises 6 parts.

[0269] Furthermore, the amount of the lees is selected from 6 to 12 parts.

[0270] Furthermore, the amount of the lees is 9 parts.

[0271] Furthermore, the number of parts of the corn germ meal is selected from 5 to 8 parts.

[0272] Furthermore, the corn germ meal comprises 6.5 parts.

[0273] Furthermore, the amount of artemisia powder is selected from 0.5 to 2.5 parts.

[0274] Furthermore, the amount of artemisia powder is 1.5 parts.

[0275] Furthermore, the amount of rice husk powder is selected from 3 to 9 parts.

[0276] Furthermore, the rice husk powder comprises 6 parts.

[0277] Furthermore, the amount of peanut shell powder is selected from 3 to 7 parts.

[0278] Furthermore, the peanut shell powder is in the form of 5 parts.

[0279] Furthermore, the amount of white stalk powder is selected from 5-10 parts.

[0280] Furthermore, the amount of white stalk powder is 7 parts.

[0281] Furthermore, the amount of alkali grass is selected from 5-10 parts.

[0282] Furthermore, the amount of alkali grass is 8 parts.

[0283] Furthermore, the premixed material is in the form of 5 parts.

[0284] Furthermore, the premix includes iron (Fe), copper (Cu), zinc (Zn), manganese (Mn), cobalt (Co), iodine (I), selenium (Se), vanadium (VA), vitamin D, vitamin E, vitamin K, vitamin B1, vitamin B2, vitamin B5, vitamin B6, and vitamin B1. 12 Vitamins B3, B9, B4, and B7.

[0285] Furthermore, the Fe content is selected from 50-100 mg / kg.

[0286] Preferably, the Fe content is 70 mg / kg.

[0287] Furthermore, the Cu content is selected from 10-30 mg / kg.

[0288] Preferably, the Cu content is 20 mg / kg.

[0289] Furthermore, the Zn content is selected from 50-100 mg / kg.

[0290] Preferably, the Zn content is 70 mg / kg.

[0291] Furthermore, the content of Mn is selected from 5-15 mg / kg.

[0292] Preferably, the Mn content is 10 mg / kg.

[0293] Furthermore, the content of Co is selected from 0.1-0.2 mg / kg.

[0294] Preferably, the content of Co is 0.15 mg / kg.

[0295] Furthermore, the content of I is selected from 0.1-0.3 mg / kg.

[0296] Preferably, the content of I is 0.2 mg / kg.

[0297] Furthermore, the content of Se is selected from 0.2-0.3 mg / kg.

[0298] Preferably, the content of Se is 0.25 mg / kg.

[0299] Furthermore, the vitamin A content is selected from 9000-11000 IU / kg.

[0300] Preferably, the vitamin A content is 10000 IU / kg.

[0301] Furthermore, the vitamin D content is selected from 800-1000 IU / kg.

[0302] Preferably, the vitamin D content is 900 IU / kg.

[0303] Furthermore, the vitamin E content is selected from 30-70 mg / kg.

[0304] Preferably, the vitamin E content is 50 mg / kg.

[0305] Furthermore, the vitamin K content is selected from 1-3 mg / kg.

[0306] Preferably, the vitamin K content is 2 mg / kg.

[0307] Furthermore, the vitamin B1 content is selected from 1-3 mg / kg.

[0308] Preferably, the vitamin B1 content is 2 mg / kg.

[0309] Furthermore, the vitamin B2 content is selected from 4-8 mg / kg.

[0310] Preferably, the vitamin B2 content is 6 mg / kg.

[0311] Furthermore, the vitamin B5 content is selected from 30-70 mg / kg.

[0312] Preferably, the vitamin B5 content is 50 mg / kg.

[0313] Furthermore, the vitamin B6 content is selected from 1-3 mg / kg.

[0314] Preferably, the vitamin B6 content is 2 mg / kg.

[0315] Furthermore, the vitamin B... 12 The content is selected from 0.01-0.03 mg / kg.

[0316] Preferably, the vitamin B 12 The content is 0.02 mg / kg.

[0317] Furthermore, the vitamin B3 content is selected from 30-70 mg / kg.

[0318] Preferably, the vitamin B3 content is 50 mg / kg.

[0319] Furthermore, the vitamin B9 content is selected from 30-60 mg / kg.

[0320] Preferably, the vitamin B9 content is 44 mg / kg.

[0321] Furthermore, the vitamin B4 content is selected from 900-1100 mg / kg.

[0322] Preferably, the vitamin B4 content is 1000 mg / kg.

[0323] Furthermore, the content of vitamin B7 is selected from 0.1-0.3 mg / kg.

[0324] Preferably, the vitamin B7 content is 0.2 mg / kg.

[0325] In one embodiment of the present invention, proline is added directly to the feed of pregnant mammals, which is convenient to operate and does not require injection or implantation, thus avoiding stress response in animals.

[0326] Beneficial effects This invention effectively alleviates the adverse effects of heat stress on female rabbits by adding proline (Pro) to the basal feed, thereby improving the reproductive performance of female rabbits, promoting the growth of kits, and enhancing the economic benefits of rabbit farming. It provides an effective nutritional regulation strategy for meat rabbit farming in summer.

[0327] Proline is easy to obtain and simple to process, making it suitable for large-scale production. Furthermore, it is highly safe as an additive, easily added directly to the feed of pregnant mammals without the need for injection or implantation, thus avoiding other stress responses in the mammals. Attached Figure Description

[0328] Figure 1 The temperature and humidity index of the rabbit hutch is used for heat stress experiments.

[0329] Figure 2 The percentage of days with heat stress. Detailed Implementation

[0330] The specific embodiments of the present invention will be further described below. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the embodiments described below can be combined with each other as long as they do not conflict with each other.

[0331] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods, and the experimental materials used in the following embodiments are all available through conventional commercial channels.

[0332] Example 1: Test Samples and Materials Rabbits: 240 standard-compliant multiparous Irae does weighing 4-4.5 kg and of similar parity were selected as experimental subjects and randomly divided into 4 groups (60 rabbits per group). All does complied with all relevant laws and regulations; namely: (1) Control group (CON group): fed with basic feed (baseline proline content 1.13%, determined according to GB / T 18246-2019) + 1.55% alanine to achieve nitrogen balance, without adding exogenous proline; (2) 0.5% proline group (0.5% Pro group): fed with basal feed (baseline 1.13%) + 0.5% exogenous proline + 1.16% alanine (isonitrogenous substitution), the total proline content of the feed was 1.63%; (3) 1% proline group (1%Pro group): fed with basal feed (baseline 1.13%) + 1.0% exogenous proline + 0.77% alanine (isonitrogenous substitution), the total proline content of the feed was 2.13%; (4) 2% Proline group (2% Pro group): fed with basic feed (baseline 1.13%) + 2.0% exogenous proline (without alanine), the total proline content of the feed was 3.13%.

[0333] The calculation begins from the day the lighting in the rabbit hutch is increased (i.e., 6 days before mating). From this time onwards, the does in each experimental group are fed the corresponding feed until the 35th day after the does give birth, for a total period of 71 days. The nutritional levels of the basal feed used are shown in Table 1.

[0334] The breeding model used in this application adopts a 42-day breeding model (the interval between matings of female rabbits commonly used in the rabbit industry), that is, mating is performed 12 days after the female rabbit gives birth. On the day of mating, artificial insemination is used to perform mating operations on the female rabbit; from the 12th to the 15th day after mating, fetal palpation is carried out to determine whether the female rabbit has successfully conceived and to calculate the conception rate; on the day the female rabbit gives birth, various reproductive indicators are recorded in detail, and thereafter, the growth and other relevant indicators of the kits are observed and recorded every 7 days until 35 days (before weaning), providing detailed data support for subsequent research.

[0335] Test instruments and equipment Table 1 shows the main experimental instruments and equipment; Table 2 shows the main reagents and consumables.

[0336] Table 1 Main Test Instruments and Equipment Table 2 Main Reagents and Experimental Consumables The basic feed for this application was formulated based on the NRC's recommended nutritional requirements for Rex rabbits (1980), and the nutritional levels of the basic feed formula are shown in Table 3.

[0337] Table 3 Nutritional levels of basal feed formulations Daily Food Design The basal diet for this experiment was formulated based on the NRC's recommended nutritional requirements for Rex rabbits (1980), and its nutritional level met the requirements of Table 3.

[0338] A. Control group feed No exogenous proline was added, and the total proline content in the feed was maintained at a baseline of 1.13%; 1.55% alanine was added to achieve isonitrogen balance. This ensured that the total nitrogen content was consistent across all groups. The raw materials used in the basic feed, by weight, included: 13 parts corn, 5 parts wheat middlings, 5 parts corn husks, 8 parts wheat bran, 1.5 parts soybean oil, 15 parts soybean meal, 6 parts rapeseed meal, 9 parts distillers' grains, 6.5 parts corn germ meal, 1.5 parts artemisia annua powder, 6 parts rice husk powder, 5 parts peanut shell powder, 7 parts white stalk powder, 8 parts alkali grass, and 5 parts premix.

[0339] Each kilogram of premix contains: Fe 70mg, Cu 20mg, Zn 70mg, Mn 10mg, Co 0.15mg, I 0.2mg, Se 0.25mg, Vitamin A 10000IU, Vitamin D 900IU, Vitamin E 50mg, Vitamin K 2mg, Vitamin B1 2mg, Vitamin B2 6mg, VB5 50mg, Vitamin B6 2mg, Vitamin B12 0.02mg, Vitamin B3 50mg, Vitamin B9 44mg, Vitamin B4 1000mg, and Vitamin B7 0.2mg.

[0340] B. 0.5% free proline feed A proline-containing feed is composed of a basal feed, 0.5% exogenous free proline, and alanine. The basal feed contains 1.13% protein-bound proline, and an additional 0.5% free proline (by weight of the basal feed) is added to bring the total proline content of the feed to 1.63%. Simultaneously, 1.16% alanine is added for isonitrogen substitution to ensure consistent total nitrogen content across all groups. The raw materials used in the basal feed, by weight, include: 13 parts corn, 5 parts wheat middlings, 5 parts corn husks, 8 parts wheat bran, 1.5 parts soybean oil, 15 parts soybean meal, 6 parts rapeseed meal, 9 parts distillers' grains, 6.5 parts corn germ meal, 1.5 parts artemisia annua powder, 6 parts rice husk powder, 5 parts peanut shell powder, 7 parts white stalk powder, 8 parts alkali grass, and 5 parts premix.

[0341] Each kilogram of premix contains: Fe 70mg, Cu 20mg, Zn 70mg, Mn 10mg, Co 0.15mg, I 0.2mg, Se 0.25mg, Vitamin A 10000IU, Vitamin D 900IU, Vitamin E 50mg, Vitamin K 2mg, Vitamin B1 2mg, Vitamin B2 6mg, Vitamin B5 50mg, Vitamin B6 2mg, Vitamin B... 12 0.02mg, Vitamin B3 50mg, Vitamin B9 44mg, Vitamin B4 1000mg and Vitamin B7 0.2mg.

[0342] C. 1% free proline feed A proline-containing feed is composed of a basal feed, 1% exogenous free proline, and alanine. The basal feed contains 1.13% protein-bound proline, and an additional 1% free proline (by weight of the basal feed) is added to bring the total proline content of the feed to 2.13%; the alanine content is 0.77%. The raw materials used in the basal feed, by weight, include: 12 parts corn, 4 parts wheat middlings, 4 parts corn husks, 7 parts wheat bran, 1 part soybean oil, 14 parts soybean meal, 5 parts rapeseed meal, 11 parts distillers' grains, 6 parts corn germ meal, 2 parts artemisia annua powder, 5 parts rice husk powder, 4 parts peanut shell powder, 6 parts white stalk powder, 7 parts alkali grass, and 6 parts premix.

[0343] Each kilogram of premix contains: Fe 60mg, Cu 15mg, Zn 60mg, Mn 10mg, Co 0.1mg, I 0.1mg, Se 0.2mg, Vitamin A 9000IU, Vitamin D 800IU, Vitamin E 40mg, Vitamin K 1mg, Vitamin B1 1mg, Vitamin B2 5mg, Vitamin B5 40mg, Vitamin B6 1mg, Vitamin B... 12 0.01mg, Vitamin B3 40mg, Vitamin B9 39mg, Vitamin B4 900mg and Vitamin B7 0.1mg.

[0344] D. 2% free proline feed A proline-containing feed is composed of a basal feed, 2% exogenous free proline, and alanine. The basal feed contains 1.13% protein-bound proline, and an additional 2% free proline (by weight of the basal feed) is added to bring the total proline content of the feed to 3.13%; no alanine is added. The raw materials used in the basal feed, by weight, include: 11 parts corn, 3 parts wheat middlings, 7 parts corn husks, 10 parts wheat bran, 0.5 parts soybean oil, 18 parts soybean meal, 8 parts rapeseed meal, 7 parts distillers' grains, 8 parts corn germ meal, 2.5 parts artemisia annua powder, 9 parts rice husk powder, 7 parts peanut shell powder, 10 parts white stalk powder, 10 parts alkali grass, and 7 parts premix.

[0345] Each kilogram of premix contains: Fe 90mg, Cu 20mg, Zn 90mg, Mn 15mg, Co 0.2mg, I 0.3mg, Se 0.3mg, Vitamin A 11000IU, Vitamin D 1000IU, Vitamin E 70mg, Vitamin K 3mg, Vitamin B1 3mg, Vitamin B2 8mg, Vitamin B5 70mg, Vitamin B6 3mg, Vitamin B... 12 0.03mg, Vitamin B3 70mg, Vitamin B9 60mg, Vitamin B4 1100mg and Vitamin B7 0.3mg.

[0346] Reproductive performance On the day of mating, collect the number of participating does; when examining the fetus, calculate the conception rate of the does; when the does give birth, collect the following data on the does's farrowing (conception rate, farrowing rate, number of litters, number of live kits in the litter, number of stillborns, total number of litters, number of live kits in the litter, total litter weight, weight of live litters, weight of live litters, average weight of live kits, weight of placenta in the litter, placental efficiency, total number of litters, total number of live kits, total weight of litters at birth, weight of live litters at birth, and average weight of live kits at birth).

[0347] Conception rate: The percentage of pregnant does out of the total number of mated does, as counted during fetal palpation; Litter rate: The percentage of female rabbits that gave birth to offspring after parturition out of the total number of breeding female rabbits; Placental efficiency = total litter weight ÷ litter weight of placenta.

[0348] Test conditions Examples 2 to 4 of this invention were all carried out under heat stress conditions.

[0349] A temperature and humidity recorder was placed in the rabbit hutch. From mating to the end of the does's farrowing, data was recorded every 2 hours from 6:00 to 18:00 daily. The temperature and humidity values ​​at 10:00 and 14:00 were extracted. The temperature and humidity index (THI) was calculated based on the dry-bulb temperature and relative humidity values. The calculation formula is as follows: THI=db-[(0.31-0.31RH)(db-14.4)]; Where THI is the temperature and humidity index (%), db is the dry-bulb temperature (°C), and RH is the relative humidity (%).

[0350] Temperature and humidity index (THI) data as follows Figure 1 As shown. The heat stress threshold (THI) for rabbits is 27.8. Based on the THI assessment value, the degree of heat stress faced by rabbits is divided into the following categories: When THI < 27.8, the rabbit was not under heat stress. When 27.8 ≤ THI < 28.9, it indicates that the rabbit is in a state of mild heat stress. When 28.9 ≤ THI < 30.0, the rabbit is in a state of severe heat stress; When THI ≥ 30.0, the rabbit is in a state of extreme heat stress.

[0351] If the test environment reaches a state of heat stress for more than 50% of the time during the entire test period, it is determined that the test environment meets the test conditions for heat stress.

[0352] Depend on Figure 2 It can be seen that during the entire experiment, the female rabbits were in a state of mild heat stress for 46.67% of the time and in a state of severe heat stress for 16.67% of the time. This indicates that the female rabbits experienced different degrees of heat stress for a total of 63.33% of the time, which is more than 50%. Therefore, it can be clearly determined that the conditions of this experiment met the criteria for heat stress, laying the foundation for subsequent research on the effects of heat stress on female rabbits.

[0353] Example 2: Effect of proline on feed intake in breeding does under heat stress conditions A. Test methods An experiment was conducted according to the grouping and feed described in Example 1, and the maternal feed intake was recorded: The feed intake of the doe was recorded in stages during the early pregnancy (from day 0 of pregnancy (mating day) to day 10), mid-pregnancy (day 11 to day 20 of pregnancy), late pregnancy (day 21 to day 29 of pregnancy (before parturition)), and lactation (day 0 of parturition (weaning day)). The method for recording the feed intake of the doe was as follows: the weight of the experimental feed given each afternoon was added to the weight of the supplementary feed given the next morning, and the difference between the weight of the supplementary feed and the remaining feed was calculated. This difference was the feed intake data of the doe for that day.

[0354] B. Test Results Table 4 shows the effect of proline-supplemented diets on the lactation capacity of breeding does under heat stress. After proline supplementation, the average daily milk production of breeding does was significantly increased compared to the control group (P<0.05); the average milk intake per litter was also significantly increased compared to the control group (P<0.05). Milk production is crucial for the growth of kits, especially before they begin eating solid food, as they rely primarily on their mother's milk for survival and development.

[0355] Table 4. Effects of proline-supplemented diets on lactation capacity of breeding does under heat stress. Table 5 shows the statistical results of feed intake in breeding does under heat stress. During early pregnancy, proline supplementation significantly increased feed intake in does (P<0.05), but there was no significant difference between different supplementation levels (P>0.05). During mid-pregnancy, feed intake in the proline-supplemented groups was slightly higher than that in the control group, but the differences were not statistically significant (P>0.05). During late pregnancy, feed intake in the 0.5% Pro group was not significantly different from that in the control group (P>0.05), while feed intake in the 1% Pro and 2% Pro groups was significantly lower than that in the control group (P<0.05), showing a dose-dependent decreasing trend. Throughout the entire pregnancy, there was no significant difference in feed intake among the groups (P>0.05). During lactation, feed intake in all proline-supplemented groups was significantly higher than that in the control group (P<0.05). In summary, supplementation with 0.5%-2% proline can significantly increase feed intake in heat-stressed does during early pregnancy and lactation, but it has a dose-dependent inhibitory effect on feed intake in late pregnancy.

[0356] Table 5. Effects of proline-supplemented feed on feed intake in breeding does under heat stress. Note: Different lowercase letters after the values ​​in the same row in the table indicate significant differences, P<0.05.

[0357] Example 3: Effects of proline on reproductive performance of female rabbits under heat stress. A. Test methods The experiment was conducted according to the grouping described in Example 1, and the grouping and feeding requirements were as follows: (1) Control group (CON group): fed with the basic feed prepared in the comparative ratio; (2) 0.5% Pro group: fed with a basal feed prepared in proportion + 5g / kg Pro; (3) 1% Pro group: fed with the prepared basic feed according to the ratio + 10g / kg Pro; (4) 2% Pro group: feed the basic feed prepared in proportion + 20g / kg Pro.

[0358] Synchronized estrus Six days before mating, turn on the light strip (white light) above the rabbit cage to stimulate the female rabbit to come into estrus. The light intensity in the center of the rabbit cage should be about 80-100 lx, and the light cycle should be 16 L:8 D. After mating, extend the light time for five days.

[0359] breeding Artificial insemination was used for breeding, with semen collected from breeding bucks in the farm's stock, and collected fresh for use. After collection, the semen was temporarily stored in a temperature-controlled refrigerator until approximately 8:00 AM on the day of breeding, when it was transported to the rabbit kennel for use. Multiple people were required for insemination: one person restrained the doe on the breeding cart, while another person, the insemination operator, lifted the doe's hindquarters and used an insemination gun to inject the collected semen into the doe's vagina. Approximately 0.5 mL of ovulation-inducing hormone No. 3 was injected into the doe's hindquarters, and her hindquarters were patted to prevent backflow of the semen.

[0360] Determining fertility The gestation period for female rabbits is generally 30-31 days. In actual production, the fetal palpation method is often used to determine whether the female rabbit is pregnant, which is performed on the 12th to 15th day after mating.

[0361] Touching the tire The operator grasps the doe's ear and neck skin with their left hand, then brings their index and middle fingers together and gently probes along the midline of the abdomen from the pelvic inlet forward, using the pads of their fingers to feel behind the 5th-6th pair of nipples. If they feel grape-sized, evenly arranged round lumps of flesh that are elastic and will slip apart when gently squeezed, then the doe is confirmed to be pregnant, and the approximate number of kits can be estimated based on the number of these lumps.

[0362] Dissection, weighing On day 19 of gestation, six pregnant does were randomly selected from each experimental group. At 8:00 AM the following day, blood was collected and the rabbits were euthanized. Fetuses and placentas were collected and weighed, and pregnancy-related information for each does was recorded. This included a series of key indicators such as total litter size, number of live fetuses, number of stillborn fetuses, total litter weight at 20 days, litter weight of live fetuses at 20 days, average weight of live fetuses at 20 days, litter weight of placenta, and placental efficiency. Placental efficiency refers to the ratio of total litter weight to litter weight of placenta. The specific calculation formula is as follows: Placental efficiency = Total litter weight ÷ Litter weight giving birth and reproduction On the first day of the pre-feeding period, the does participating in this experiment were subjected to photo-synchronized estrus treatment. After the does came into estrus, artificial insemination was performed on the first day of the main trial period, and the does were accurately marked. From day 12 to 15 post-mating, fetal palpation was performed to determine pregnancy status, and the conception rate for each group was recorded. After the does gave birth, the following data was recorded for each does: litter size, total litter size, total live births, litter size, litter size, litter size, litter size, and stillbirths. The conception rate refers to the percentage of successful pregnancies after mating; the litter size is the percentage of litters actually born; the total litter size is the product of the litter size and the litter size; and the total live births are the product of the number of live births and the litter size. The specific calculation formulas are as follows: A = (a / m) × 100%; B = (b / m) × 100%; C = c × B; D = d × B.

[0363] Where A is the conception rate (%), a is the number of pregnant does (number of rabbits), m is the number of mating does (number of rabbits), B is the litter rate (%), b is the number of parturing does (number of rabbits), C is the total litter size (number of rabbits), c is the total litter size (number of rabbits), D is the total number of live kits (number of rabbits), and d is the total number of live kits (number of rabbits).

[0364] B. Reproductive performance determination in female rabbits at 20 days of gestation. The reproductive performance data of the female rabbits are shown in Table 6. Since the number of stillbirths in each group was 0, the total number of litters was consistent with the number of live litters, and the total litter weight at 20 days was consistent with the live litter weight. Regarding the total number of litters (live litters), the 0.5% and 1% PRO groups showed a significant increase compared to the control group (P<0.05), with increases of 1.83 and 2.00 litters, respectively. As for the total litter weight at 20 days (i.e., live litter weight), all proline-added groups were significantly higher than the control group (P<0.05), with increases of 6.19g, 8.52g, and 7.67g in the 0.5%, 1%, and 2% PRO groups, respectively, but the differences between groups were not significant (P>0.05). Regarding the average live litter weight at 20 days, the 1% and 2% PRO groups showed a significant increase compared to the control group (P<0.05), with increases of 0.26g and 0.66g, respectively, while there was no significant difference in the 0.5% PRO group. Regarding placental weight, all supplemented groups showed significantly higher weights than the control group (P<0.05). The 0.5%, 1%, and 2% PRO groups increased placental weight by 1.82g, 3.17g, and 2.94g, respectively, with no significant differences between groups. In terms of placental efficiency, the 0.5% PRO group showed a 0.11% improvement compared to the control group (P>0.05). In conclusion, the 0.5% and 1% PRO groups showed better improvement in reproductive performance of gestational rabbits at 20 days of gestation under heat stress.

[0365] Table 6. Effects of proline-supplemented diet on reproductive performance of pregnant rabbits at 20 days of gestation under heat stress. Note: Different lowercase letters after the values ​​in the same row in the table indicate significant differences, P<0.05; control group (basal feed), 0.5%PRO group (basal feed + 5g / kg Pro), 1%PRO group (basal feed + 10g / kg Pro), 2%PRO group (basal feed + 20g / kg Pro).

[0366] C. Determination of female rabbit reproductive performance The reproductive performance data of the female rabbits are shown in Table 7. Regarding conception rate and litter size, the litter size of the 0.5% PRO group was 11.88% higher than the control group (P>0.05), while there were no significant differences among the proline-added groups (P>0.05), and the litter size decreased with increasing dosage. In terms of litter size, all added groups were significantly higher than the control group (P<0.05), with the 0.5%, 1%, and 2% PRO groups increasing by 0.88, 1.07, and 0.84 piglets respectively, with no significant differences among the groups (P>0.05). Regarding the number of live piglets per litter, compared to the control group, the 0.5% and 1% PRO groups increased by 0.98 and 0.79 piglets respectively (P<0.05), while the increase in the 2% PRO group was not significant (P>0.05). In terms of total litter size, the 0.5% PRO group was significantly higher than the control group (P<0.05), with an increase of 1.40 pups; the 1% PRO group showed no significant difference (P>0.05); and the 2% PRO group showed a significant decrease (P<0.05), with a reduction of 0.52 pups, exhibiting a dose-dependent decreasing trend. In terms of total live pups, compared to the control group, the 0.5% PRO group significantly increased by 1.42 pups (P<0.05), the 1% PRO group showed no significant difference from the control group (P>0.05), and the 2% PRO group significantly decreased by 0.65 pups (P<0.05). The number of stillbirths increased with increasing dosage, with the 2% PRO group showing a significant increase of 0.43 pups compared to the control group (P<0.05). Only the 0.5% PRO group showed a significant increase in total litter weight and live litter weight at birth (P<0.05), increasing by 90.18g and 93.84g respectively; the other two groups showed no significant differences. There was no significant difference in the average weight of live offspring among the groups (P>0.05).

[0367] Under normal circumstances, the late stage of pregnancy is the main stage of rabbit development. However, under heat stress, the absorption rate of nutrients during this period decreases, resulting in a lower embryo survival rate. Adding proline improves the absorption rate of the placenta in rabbits and increases their survival rate.

[0368] In conclusion, feed with 0.5% Pro added is the best for improving the reproductive performance of heat-stressed female rabbits.

[0369] Table 7. Effects of proline-supplemented diets on reproductive performance of heat-stressed female rabbits. Note: Different lowercase letters after the values ​​in the same row in the table indicate significant differences, P<0.05; control group (basal diet), 0.5%PRO group (basal diet + 5g / kg Pro), 1%PRO group (basal diet + 10g / kg Pro), 2%PRO group (basal diet + 20g / kg Pro).

[0370] Example 4: Effects of proline on growth performance of baby rabbits under heat stress A. Test methods After the baby rabbits are born, to ensure consistent growth conditions for each litter, litter mixing should be performed as early as possible to maintain a balance in size and number of kits. Typically, baby rabbits begin to grow fur around 5 days after birth, open their eyes around 12 days, and can begin eating feed after 18 days. After a period of adaptation to feed (around ten days), the baby rabbits develop a certain degree of independent survival ability, and are therefore weaned at 35 days. Data is recorded throughout the kits' growth process, including the number of kits in litters at 7, 14, 21, and 35 days, and the litter weight is measured with the kits on an empty stomach. Based on the recorded number of kits and the measured litter weight, the average weight of the baby rabbits is calculated.

[0371] B. Test Results The growth performance data of the baby rabbits are shown in Table 8. On day 7, the number of baby rabbits in each proline-added group was significantly higher than that in the control group (P<0.05); in terms of litter weight, the 0.5% and 1% PRO groups were significantly higher than the control group (P<0.05), while the 2% PRO group did not differ significantly from the control group (P>0.05); in terms of average weight of baby rabbits, there was no significant difference among the groups (P>0.05). On day 14, only the 1% PRO group had a significantly higher number of baby rabbits than the control group (P<0.05); the litter weight of baby rabbits in each proline-added group was significantly higher than that in the control group (P<0.05); in terms of average weight of baby rabbits, the 2% PRO group was significantly higher than the control group (P<0.05), while the 0.5% and 1% PRO groups did not differ significantly from the control group (P>0.05). On day 21, the number of litters in the 1% and 2% PRO groups was significantly higher than that in the control group (P<0.05), while the 0.5% PRO group showed no significant difference compared to the control group (P>0.05). The litter weight of all proline-added groups was significantly higher than that in the control group (P<0.05), with no significant difference between groups (P>0.05). Regarding the average weight of the kits, only the 2% PRO group was significantly higher than the control group (P<0.05). On day 35, the number of litters and litter weight of all proline-added groups were significantly higher than those in the control group (P<0.05). Regarding the average weight of the kits, the 0.5% PRO group was significantly higher than the control group (P<0.05), while the 1% and 2% PRO groups showed no significant difference compared to the control group (P>0.05). In conclusion, the feed supplemented with 0.5% Pro best improves the growth performance of heat-stressed kits.

[0372] Table 8. Effects of proline-supplemented feed on growth performance of offspring rabbits under heat stress. Note: Different lowercase letters after the values ​​in the same row in the table indicate significant differences, P<0.05. Control group (basal diet), 0.5%PRO group (basal diet + 5g / kg Pro), 1%PRO group (basal diet + 10g / kg Pro), 2%PRO group (basal diet + 20g / kg Pro).

Claims

1. A feed for improving the reproductive performance of mammals under heat stress conditions, the feed comprising proline and a complete diet; the proline content in the feed being selected from 1.63% to 3.13%; the alanine content being selected from 0 to 1.16%, used to balance the total nitrogen content among groups; the complete diet comprising corn, wheat middlings, corn bran, wheat bran, soybean oil, soybean meal, rapeseed meal, distillers' grains, corn germ meal, artemisia annua powder, rice husk powder, peanut shell powder, white stalk powder, alkali grass, and premix.

2. The feed as described in claim 1, wherein the mammal is a mammal under stress conditions; the stress condition is heat stress; the mammal includes mice, rats, pigs, cattle, sheep, horses, deer, foxes, mink, and rabbits; the reproductive performance includes litter size, litter live birth, total litter size, total live birth, litter stillbirth, total birth weight, total litter size, total litter live birth, total litter weight, litter weight of live births, litter placental weight, and birth weight of live births; the proline includes basal feed proline and exogenous proline; the amount of exogenous proline added is 0.5%; the alanine content is... 1.16%; the corn component is 13 parts; the wheat middlings component is 5 parts, the corn husk component is 5 parts, the wheat bran component is 8 parts, the soybean oil component is 1.5 parts, the soybean meal component is 15 parts, the rapeseed meal component is 6 parts, the distillers' grains component is 9 parts, the corn germ meal component is 6.5 parts, the artemisia annua powder component is 1.5 parts, the rice husk powder component is 6 parts, the peanut shell powder component is 5 parts, the white stalk powder component is 7 parts, the alkali grass component is 8 parts; the premix component is 5 parts; each kilogram of premix contains Fe 70mg, Cu 20mg, Zn 70mg, Mn 10mg, Co 0.15mg, I 0.2mg, Se 0.25mg, Vitamin A 10000IU, Vitamin D 900IU, Vitamin E 50mg, Vitamin K 2mg, Vitamin B1 2mg, Vitamin B2 6mg, VB5 50mg, Vitamin B6 2mg, Vitamin B12 0.02mg, Vitamin B3 50mg, Vitamin B9 44mg, Vitamin B4 1000mg, and Vitamin B7 0.2mg.

3. The use of the feed as described in claim 1 in the preparation of products that improve the reproductive performance of mammals.

4. The application as described in claim 3, wherein the mammal is a mammal under stress conditions; the stress condition is heat stress; the mammal includes mice, rats, pigs, cattle, sheep, horses, deer, foxes, mink, and rabbits; the reproductive performance includes litter size, litter live birth, total litter size, total live birth, litter stillbirth, total birth weight, total litter size, total litter live birth, total litter weight, litter weight of live births, litter placental weight, and birth weight of live births; the proline includes basal feed proline and exogenous proline; the amount of exogenous proline added is 0.5%; the alanine content is... 1.16%; the corn component is 13 parts; the wheat middlings component is 5 parts, the corn husk component is 5 parts, the wheat bran component is 8 parts, the soybean oil component is 1.5 parts, the soybean meal component is 15 parts, the rapeseed meal component is 6 parts, the distillers' grains component is 9 parts, the corn germ meal component is 6.5 parts, the artemisia annua powder component is 1.5 parts, the rice husk powder component is 6 parts, the peanut shell powder component is 5 parts, the white stalk powder component is 7 parts, the alkali grass component is 8 parts; the premix component is 5 parts; each kilogram of premix contains Fe 70mg, Cu 20mg, Zn 70mg, Mn 10mg, Co 0.15mg, I 0.2mg, Se 0.25mg, Vitamin A 10000IU, Vitamin D 900IU, Vitamin E 50mg, Vitamin K 2mg, Vitamin B1 2mg, Vitamin B2 6mg, VB5 50mg, Vitamin B6 2mg, Vitamin B12 0.02mg, Vitamin B3 50mg, Vitamin B9 44mg, Vitamin B4 1000mg, and Vitamin B7 0.2mg.

5. A feed for improving the growth performance of mammalian offspring under heat stress conditions, the feed comprising proline and a complete diet; the proline content in the feed being selected from 1.63%-3.13%; the alanine content being selected from 0-1.16%, used to balance the total nitrogen content among groups; the complete diet comprising corn, wheat middlings, corn bran, wheat bran, soybean oil, soybean meal, rapeseed meal, distillers' grains, corn germ meal, artemisia annua meal, rice husk meal, peanut shell meal, white stalk meal, alkali grass, and premix.

6. The feed as described in claim 5, wherein the mammal is a mammal under stress conditions; the stress conditions are heat stress; the mammal includes mice, rats, pigs, cattle, sheep, horses, deer, foxes, mink, and rabbits; the growth performance includes litter size, litter weight, and average litter weight; the proline includes basal feed proline and exogenous proline; the amount of exogenous proline added is 0.5%; the alanine content is 1.16%; the corn component is 13 parts; and the wheat middlings component is 5 parts. The composition comprises: 5 parts corn husk, 8 parts wheat bran, 1.5 parts soybean oil, 15 parts soybean meal, 6 parts rapeseed meal, 9 parts distillers' grains, 6.5 parts corn germ meal, 1.5 parts artemisia annua powder, 6 parts rice husk powder, 5 parts peanut shell powder, 7 parts white stalk powder, and 8 parts alkali grass; the premix comprises 5 parts; each kilogram of premix contains Fe. 70mg, Cu 20mg, Zn 70mg, Mn 10mg, Co 0.15mg, I 0.2mg, Se 0.25mg, Vitamin A 10000IU, Vitamin D 900IU, Vitamin E 50mg, Vitamin K 2mg, Vitamin B1 2mg, Vitamin B2 6mg, VB5 50mg, Vitamin B6 2mg, Vitamin B12 0.02mg, Vitamin B3 50mg, Vitamin B9 44mg, Vitamin B4 1000mg, and Vitamin B7 0.2mg.

7. The use of the feed as described in claim 5 in the preparation of products that improve the growth performance of mammalian offspring.

8. The application as described in claim 7, wherein the mammal is a mammal under stress conditions; the stress condition is heat stress; the mammal includes mice, rats, pigs, cattle, sheep, horses, deer, foxes, mink, and rabbits; the growth performance includes litter size, litter weight, and average litter weight; the proline includes basal feed proline and exogenous proline; the amount of exogenous proline added is 0.5%; the alanine content is 1.16%; the corn component is 13 parts; and the wheat middlings component is 5 parts. The composition comprises: 5 parts corn husk, 8 parts wheat bran, 1.5 parts soybean oil, 15 parts soybean meal, 6 parts rapeseed meal, 9 parts distillers' grains, 6.5 parts corn germ meal, 1.5 parts artemisia annua powder, 6 parts rice husk powder, 5 parts peanut shell powder, 7 parts white stalk powder, and 8 parts alkali grass; the premix comprises 5 parts; each kilogram of premix contains Fe. 70mg, Cu 20mg, Zn 70mg, Mn 10mg, Co 0.15mg, I 0.2mg, Se 0.25mg, Vitamin A 10000IU, Vitamin D 900IU, Vitamin E 50mg, Vitamin K 2mg, Vitamin B1 2mg, Vitamin B2 6mg, VB5 50mg, Vitamin B6 2mg, Vitamin B12 0.02mg, Vitamin B3 50mg, Vitamin B9 44mg, Vitamin B4 1000mg, and Vitamin B7 0.2mg.

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