A method for improving the reproductive performance of mammals

Abstract

The present invention discloses the use of tryptophan in preparing a medicine and a feed additive for improving the reproductive performance of mammals. The present invention also discloses a method for improving the reproductive performance of mammals by feeding tryptophan during a specific gestation period. The method of the present invention can alleviate the heat stress of mammals during gestation and improve the reproductive performance of mammals.

Description

Technical Field

[0001] The invention belongs to the field of agricultural animal husbandry, and specifically relates to a method for improving the reproductive performance, antioxidant capacity and / or immunity of mammals. Background Art

[0002] my country is a major livestock producer and consumer of livestock and poultry products, and has a great demand for meat products. Among them, pork is the main meat consumed by Chinese residents. In 2022, the global pork production was about 125 million tons, and China's pork production was 55.41 million tons. China's pork production accounted for about 44.47% of the global pork production. Its sales in the market have remained high, and the market demand is still expanding. However, due to the influence of environmental, nutritional, genetic, stress and other factors, my country's pig inventory and output still need to be improved. In 2022, my country's annual pig output was about 700 million, while the inventory of sows was only 43.8 million, with an average of only 20 sows, and the actual number of piglets born alive by sows was far from enough, and its survival rate was even lower. A big reason for this is that the stress (heat stress) caused by environmental factors on sows causes embryonic death and reduced sow feed intake. If veterinary drugs are administered to relieve sow stress or increase the live piglet birth rate, problems such as veterinary drug residues and drug withdrawal periods may occur.

[0003] Tryptophan (Trp), chemical name is L-2-amino-3 (β-indole) propionic acid (C 11 H 12 N2O2), can participate in the renewal of plasma proteins in animals, promote the role of riboflavin, and contribute to the synthesis of niacin and heme. However, there is currently no research or report on the correlation between tryptophan and the reproductive performance of mammals.

[0004] Therefore, it is crucial for meat animals to find a way to reduce stress and improve reproductive performance in mammals. Summary of the invention

[0005] In order to solve one of the above technical problems existing in the prior art, the present invention provides a method for improving the reproductive performance, antioxidant capacity and / or immunity of mammals by feeding tryptophan.

[0006] In order to achieve the above-mentioned purpose, the technical solution provided by the present invention is as follows.

[0007] In a first aspect, the present invention provides the use of tryptophan in the preparation of a medicine and / or a feed additive for improving the reproductive performance, antioxidant capacity and / or immunity of a mammal.

[0008] In some embodiments, the reproductive performance includes one or more of average litter weight at birth, average litter weight at weaning, survival rate at birth, and survival rate at weaning.

[0009] In some embodiments, the mammals include mice, rats, pigs, cows, sheep, horses, deer, foxes, and minks.

[0010] In some embodiments, the mammal is a pig.

[0011] In some embodiments, the tryptophan of the present invention is L-tryptophan.

[0012] In a second aspect, the present invention provides a method for improving the reproductive performance, antioxidant capacity and / or immunity of a mammal, the method comprising adding tryptophan to the feed of a pregnant mammal.

[0013] In some embodiments, tryptophan can be directly added to the feed of pregnant mammals, which is convenient to operate and does not require injection or implantation, thus avoiding stress reactions in animals.

[0014] In some embodiments, only tryptophan is added to the feed.

[0015] In some embodiments, the added amount of tryptophan is 0.1%-0.2% of the mammal's daily diet, for example, it can be 0.1%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19% or 0.2%.

[0016] In some embodiments, the tryptophan is added in early pregnancy and / or late pregnancy. Early pregnancy can include pregnancy day 0 to the first 1 / 3 of the gestational period, and late pregnancy can include the last 1 / 3 of the gestational period to delivery.

[0017] In some embodiments, the tryptophan is added during early pregnancy.

[0018] Feeding tryptophan in early pregnancy of mammals can reduce serum malondialdehyde levels, increase superoxide dismutase and total antioxidant capacity levels, and help improve the body's antioxidant levels. At the same time, it can increase interleukin-10 levels, allowing anti-inflammatory factors to play a major role, which is beneficial for early embryo implantation and reduces embryo loss.

[0019] In some embodiments, the tryptophan is added during late pregnancy.

[0020] Feeding tryptophan in late pregnancy of mammals can increase the content of interleukin-6, reduce the content of interleukin-10, and make pro-inflammatory factors play a major role, which helps to promote delivery. At the same time, the content of malondialdehyde tends to decrease, and the levels of superoxide dismutase and total antioxidant capacity tend to increase, which is beneficial to improve the body's antioxidant performance, enhance the body's immunity, and increase the survival rate.

[0021] In some embodiments, the tryptophan is added during early pregnancy and late pregnancy.

[0022] By feeding tryptophan at specific early and / or late stages of pregnancy, the problems of severe embryonic loss in early pregnancy and / or intrauterine growth retardation of embryos in late pregnancy are effectively solved, ensuring the safety of embryos during pregnancy, thereby increasing the average litter weight and pup survival rate, etc., and thus improving the reproductive performance of mammals.

[0023] In some embodiments, the mammals include mice, rats, pigs, cows, sheep, horses, deer, foxes, and minks.

[0024] In some embodiments, the mammal is a pig.

[0025] In some embodiments, for pregnant sows, tryptophan is added during gestational days 0-14 and / or gestational days 99-114.

[0026] In some embodiments, for pregnant sows, tryptophan is added during gestational days 0-14, preferably gestational days 0 to 7.

[0027] In some embodiments, for pregnant sows, tryptophan is added between days 99-114 of pregnancy, preferably between days 99 and 107 of pregnancy.

[0028] In some embodiments, for pregnant sows, tryptophan is added during gestation days 0-14 and 99-114.

[0029] In some embodiments, for pregnant sows, the daily dose of tryptophan is 3-6 g / day, for example, 3 g / day, 4 g / day, 5 g / day, 6 g / day. The daily tryptophan can be fed in divided portions or once, for example, once in the morning.

[0030] In some embodiments, the mammal is administered tryptophan 2-5 times.

[0031] In some embodiments, the reproductive performance includes one or more of average litter weight at birth, average litter weight at weaning, survival rate at birth, and survival rate at weaning.

[0032] In some embodiments, the tryptophan of the present invention is L-tryptophan.

[0033] The beneficial effects of the present invention are:

[0034] By feeding tryptophan to pregnant sows, the reproductive performance of pregnant sows can be improved. This method can not only achieve convenient addition on demand, but also adjust the dosage in time, avoiding the stress of sows that may be caused by injection or implantation. Surprisingly, the present invention has found through animal experiments that feeding tryptophan to sows in a specific gestation period can significantly improve the birth survival rate of piglets, and the average birth weight and average weaning weight of piglets have a significant upward trend. It can also improve the antioxidant capacity and immunity of sows, thereby effectively improving the reproductive performance of sows. Through the method of the present invention, the sow's live piglet rate can be improved, the number of live pigs sold can be increased, and the time to sell can be shortened, and greater economic benefits can be obtained at the same production cost, and there is no side effect on the sow itself. It also avoids problems such as veterinary drug residues and drug withdrawal periods, is safe and effective, and can improve the production efficiency of the pig farming industry.

[0035] Furthermore, the present invention can improve the immunity of sows, reduce the heat stress of pregnant sows, and improve the survival rate of piglets by feeding tryptophan to sows in a specific gestation period, thereby achieving the purpose of improving the reproductive performance of pregnant sows. The method of the present invention is not only applicable to pigs, but also can be extended to other meat products, such as livestock such as sheep, cattle, and horses, and other mammals, such as mice, rats, deer, foxes, and minks. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Shown are changes in serum tryptophan levels in sows fed tryptophan during early gestation.

[0037] Figure 2 The figure shows the average litter weight of piglets at birth and at weaning after farrowing of sows in early pregnancy.

[0038] Figure 3 The results show the birth survival rate and weaning survival rate of piglets from sows fed tryptophan in early pregnancy.

[0039] Figure 4 The effects of feeding tryptophan in early pregnancy on the antioxidant capacity of sow serum are shown, including (A) changes in the malondialdehyde content of sow serum; (B) changes in the superoxide dismutase content of sow serum; (C) changes in the total antioxidant capacity of sow serum.

[0040] Figure 5 The effect of feeding tryptophan in early pregnancy on serum interleukin levels in sows is shown, including (A) changes in serum interleukin-6 (IL-6) content in sows; (B) changes in serum interleukin-10 (IL-10) content in sows.

[0041] Figure 6 Shown are changes in serum tryptophan levels in sows fed tryptophan during late gestation.

[0042] Figure 7 The figure shows the average litter weight of piglets at birth and at weaning after farrowing of sows in late pregnancy.

[0043] Figure 8 The results show the birth survival rate and weaning survival rate of piglets after farrowing of sows fed tryptophan in late pregnancy.

[0044] Fig. 9 The effects of feeding tryptophan in late pregnancy on the antioxidant capacity of sow serum are shown, including (A) changes in the malondialdehyde content of sow serum; (B) changes in the superoxide dismutase content of sow serum; (C) changes in the total antioxidant capacity of sow serum.

[0045] Fig.10 The effect of feeding tryptophan in late pregnancy on serum interleukin levels in sows is shown, including (A) changes in serum interleukin-6 (IL-6) content in sows; (B) changes in serum interleukin-10 (IL-10) content in sows. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with embodiments. The specific embodiments described herein are only used to explain the present invention and are not intended to constitute any limitation of the present invention. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concepts of the present disclosure. Such structures and technologies are also described in many publications.

[0047] definition

[0048] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as commonly used in the field to which the present invention belongs. For the purpose of interpreting this specification, the following definitions will apply, and where appropriate, terms used in the singular will also include the plural form, and vice versa.

[0049] Unless the context clearly dictates otherwise, the expressions "a", "an" and "an" as used herein include plural references. For example, reference to "a cell" includes a plurality of such cells and equivalents thereof known to those skilled in the art, etc.

[0050] As used herein, the term "about" refers to a range of ±20% of the value that follows. In some embodiments, the term "about" refers to a range of ±10% of the value that follows. In some embodiments, the term "about" refers to a range of ±5% of the value that follows.

[0051] Examples and drawings are provided below to help understand the present invention. However, it should be understood that these examples and drawings are only used to illustrate the present invention, but do not constitute any limitation. The actual protection scope of the present invention is set forth in the claims. It should be understood that any modifications and changes can be made without departing from the spirit of the present invention.

[0052] The reagents and materials used in the following examples are all commercially available products. Tryptophan (Trp) used was purchased from Xi'an Musen Bioengineering Co., Ltd.

[0053] The feed in the following embodiments mainly includes:

[0054]

[0055] Experimental Example 1. Effect of feeding tryptophan on reproductive performance of early gestation sows

[0056] 1. Experimental Animals and Methods

[0057] This experiment selected 21 early pregnant sows with good growth and similar weight, with an initial average weight of about 200kg, and randomly divided them into 3 groups, namely the control group, the 0.1% Trp test group and the 0.2% Trp test group, with 7 replicates in each group. The control group was fed normally, with each pig fed 3kg of feed per day. The 0.1% Trp group and the 0.2% Trp group added L-tryptophan to the sows' diets regularly and quantitatively during the first 15 days of early pregnancy (from day 0 to day 14 of pregnancy), with the added doses of 0.1% and 0.2% of the diet, i.e. 3g and 6g, respectively. The sows were fed once in the morning, and no stress response occurred in the sows. The whole blood of the sows was collected before feeding, on the 7th day of early pregnancy, and on the 14th day of early pregnancy, respectively. The whole blood was centrifuged at 3000r / min for 10min, and the supernatant was frozen at -20℃ for testing. The blood collection method for sows was the abdominal venous blood collection method. The experiment was carried out in the summer (June, July and August) at Yantai Fuzu Animal Husbandry Co., Ltd.

[0058] Serum IL-6 and IL-10 were measured by double antibody sandwich enzyme-linked immunosorbent assay (ELISA), malondialdehyde, superoxide dismutase and total antioxidant capacity were determined by colorimetry, serum tryptophan was determined by liquid chromatography-mass spectrometry, and the farrowing conditions of sows and piglets at weaning were calculated.

[0059] 2. Experimental results

[0060] (1) Effect of feeding tryptophan in early pregnancy on serum tryptophan content in sows. The results are shown in Tables 1 and Figure 1 .

[0061] Table 1

[0062]

[0063] As shown in Table 1 and Figure 1 As shown in the figure, the tryptophan levels of each group were similar before feeding. On the 7th day of early pregnancy, the serum tryptophan content of sows in the 0.1% Trp group was significantly higher than that in the control group, and the serum tryptophan content of sows in the 0.2% Trp group was significantly higher than that in the control group. On the 14th day of early pregnancy, the serum tryptophan in the 0.1% Trp group and the 0.2% Trp group was still higher than that in the control group.

[0064] (2) Effects of feeding tryptophan in early pregnancy on birth weight and weaning weight of piglets after sow farrowing. The results are shown in Tables 2 and Figure 2 .

[0065] Table 2

[0066] Group Average litter weight of piglets at birth (kg) Average litter weight of piglets at weaning (kg) Comparison 1.51 7.06 0.1%Trp 1.79 7.78 0.2%Trp 1.81 9.95

[0067] As shown in Table 2 and Figure 2 As shown, after feeding tryptophan in early pregnancy, the average litter weight of piglets at birth in the 0.1% Trp group and the 0.2% Trp group showed an upward trend compared with the control group; the average litter weight of piglets at weaning in the 0.1% Trp group and the 0.2% Trp group showed an upward trend compared with the control group.

[0068] (3) Effects of feeding tryptophan in early pregnancy on the birth survival rate and weaning survival rate of piglets after sow farrowing. The results are shown in Tables 3 and Figure 3 .

[0069] Table 3

[0070]

[0071]

[0072] As shown in Table 3 and Figure 3 As shown, after feeding tryptophan in early pregnancy, the birth survival rate of piglets in the 0.1% Trp group and the 0.2% Trp group showed an upward trend compared with the control group; the weaning survival rate of piglets in the 0.1% Trp group and the 0.2% Trp group showed an upward trend compared with the control group.

[0073] (4) Effect of feeding tryptophan in early pregnancy on serum antioxidant levels in sows. The results are shown in Tables 4 and Figure 4 .

[0074] Table 4

[0075]

[0076] like Figure 4 As shown in A, the levels of malondialdehyde (MDA) in each group were similar before feeding began; on the 7th day of early pregnancy, the levels of MDA in the experimental group were lower than those in the control group. Figure 4 As shown in B, the levels of superoxide dismutase (SOD) in each group were similar before feeding; on the 7th day of early pregnancy, the levels of superoxide dismutase in the experimental group were higher than those in the control group. Figure 4 As shown in C, the total antioxidant capacity (T-AOC) of the serum of sows in each group was equivalent before feeding began; on the 7th day of early pregnancy, the total antioxidant level of the experimental group was higher than that of the control group.

[0077] Compared with the control group, after feeding tryptophan, the serum malondialdehyde content of sows in early pregnancy was lower and the superoxide dismutase content was higher, indicating that feeding tryptophan can improve the antioxidant capacity of the serum of pregnant sows.

[0078] (5) Effects of feeding tryptophan in early pregnancy on serum interleukin (IL-6 and IL-10) levels in sows. The results are shown in Tables 5 and Figure 5 .

[0079] Table 5

[0080]

[0081]

[0082] like Figure 5 As shown in A, the IL-6 levels of each group were similar before feeding began; on the 7th day of early pregnancy, the IL-6 level of the experimental group was lower than that of the control group. Figure 5 As shown in B, the IL-10 levels of each group were similar before feeding began; on the 7th day of early pregnancy, the IL-10 level in the experimental group was higher than that in the control group.

[0083] After feeding tryptophan to sows in early pregnancy, the level of interleukin-10 in the sows' serum increased, indicating that feeding tryptophan can promote embryo implantation in pregnant sows, reduce embryo loss, and thus improve the reproductive performance and immunity of sows.

[0084] Experimental Example 2. Effect of feeding tryptophan on reproductive performance of sows in late pregnancy

[0085] 1. Experimental Animals and Methods

[0086] This experiment selected 21 late-pregnancy sows with good growth and similar weight, with an initial average weight of about 200kg, and randomly divided them into 3 groups, namely the control group, the 0.1% Trp test group and the 0.2% Trp test group, with 7 replicates in each group. The control group was fed normally, with each pig fed 3kg of feed per day. The 0.1% Trp group and the 0.2% Trp group added L-tryptophan to the sows' diets at regular intervals and quantitatively in the last 16 days of the late pregnancy of the sows (99th to 114th day of pregnancy), respectively. The added doses were 0.1% and 0.2% of the diet, i.e. 3g and 6g, respectively. The sows were fed once in the morning, and no stress response occurred in the sows. The whole blood of the sows was collected before feeding, on the 107th day of late pregnancy, and on the 114th day of late pregnancy, respectively. The whole blood was centrifuged at 3000r / min for 10min, and the supernatant was frozen at -20℃ for testing. The blood collection method for sows was the abdominal venous blood collection method. The experiment was carried out in the summer (August) at Yantai Fuzu Animal Husbandry Co., Ltd.

[0087] Serum IL-6 and IL-10 were measured by double antibody sandwich enzyme-linked immunosorbent assay (ELISA), malondialdehyde, superoxide dismutase and total antioxidant capacity were determined by colorimetry, serum tryptophan was determined by liquid chromatography-mass spectrometry, and the farrowing conditions of sows and piglets at weaning were calculated.

[0088] 2. Experimental results

[0089] (1) Effect of feeding tryptophan in late pregnancy on serum tryptophan content in sows. The results are shown in Tables 6 and Figure 6 .

[0090] Table 6

[0091]

[0092] As shown in Table 6 and Figure 6 As shown in the figure, the tryptophan levels of each group were similar before feeding. On the 107th day of gestation, the serum tryptophan content of sows in the 0.1% Trp group was significantly higher than that in the control group, and the serum tryptophan content of sows in the 0.2% Trp group was significantly higher than that in the control group. On the 114th day of gestation, the serum tryptophan content of sows in the 0.1% Trp group and the 0.2% Trp group was still higher than that in the control group.

[0093] (2) Effects of feeding tryptophan in late pregnancy on birth weight and weaning weight of piglets after sow farrowing. The results are shown in Tables 7 and Figure 7 .

[0094] Table 7

[0095] Group Average litter weight of piglets at birth (kg) Average litter weight of piglets at weaning (kg) Comparison 1.42 4.93 0.1%Trp 2.09 5.87 0.2%Trp 2.01 5.98

[0096] As shown in Table 7 and Figure 7As shown, after feeding tryptophan in late pregnancy, the average litter weight of piglets at birth in the 0.1% Trp group and the 0.2% Trp group tended to increase compared with the control group; the average litter weight of piglets at weaning, compared with the control group, the average litter weight of piglets at weaning in the 0.1% Trp group and the 0.2% Trp group both tended to increase.

[0097] (3) The effect of feeding tryptophan in late pregnancy on the birth survival rate and weaning survival rate of piglets after sow farrowing. The results are shown in Table 8 and Figure 8 .

[0098] Table 8

[0099] Group Piglet birth survival rate (%) Piglet weaning survival rate (%) Comparison 0.88 0.78 0.1%Trp 0.94 0.94 0.2%Trp 0.91 0.96

[0100] As shown in Table 8 and Figure 8 As shown, after feeding tryptophan in late pregnancy, the birth survival rate of piglets in the 0.1% Trp group and the 0.2% Trp group showed an upward trend compared with the control group; the weaning survival rate of piglets in the 0.1% Trp group and the 0.2% Trp group was higher than that in the control group.

[0101] (4) Effect of feeding tryptophan in late pregnancy on serum antioxidant levels in sows. The results are shown in Tables 9 and Fig. 9 .

[0102] Table 9

[0103]

[0104]

[0105] like Fig. 9 As shown in A, the malondialdehyde (MDA) levels of each group were similar before feeding began; on days 107-114 of gestation, the MDA content of the experimental group showed a decreasing trend. Fig. 9 As shown in B, the levels of superoxide dismutase (SOD) in each group were similar before feeding; on days 107-114 of gestation, the levels of superoxide dismutase in the experimental group tended to increase. Fig. 9 As shown in C, the total antioxidant capacity (T-AOC) of the serum of sows in each group was equivalent before feeding began; from 107th to 114th day of gestation, the total antioxidant level of the experimental group tended to increase.

[0106] (5) Effects of feeding tryptophan in late pregnancy on serum interleukin (IL-6 and IL-10) levels in sows. The results are shown in Tables 10 and Fig.10 .

[0107] Table 10

[0108]

[0109] like Fig.10 As shown in A, the IL-6 levels of each group were similar before feeding began; on days 107 and 114 of gestation, the IL-6 level of the experimental group was higher than that of the control group. Fig.10 As shown in B, the IL-10 levels of each group were similar before feeding began; on the 107th day of gestation, the IL-10 level of the experimental group was lower than that of the control group.

[0110] After feeding tryptophan to sows in late pregnancy, interleukin-6 in late pregnancy increased, which can promote sow farrowing and increase the survival rate.

[0111] The present invention feeds tryptophan to sows in a specific gestation period, and surprisingly finds that the content of tryptophan in the serum of sows can be significantly increased, the survival rate of piglets can be improved, and the average birth weight and average weaning weight of piglets can be improved. At the same time, the antioxidant performance of the sow body can be significantly improved and the immunity can be improved. Therefore, the method of the present invention can effectively avoid sow stress, is conducive to improving the survival rate of piglets after sows give birth, and will not have adverse effects on the number of live piglets and weaning weight of piglets during weaning, thereby improving the reproductive performance of sows.

[0112] The above description is only a general description of the present invention and a description of a specific embodiment, and does not limit the present invention in other forms. Any person skilled in the art can modify or modify the technical content disclosed in this application to an equivalent embodiment. Without departing from the concept and spirit of the present invention, any modification or modification of the present invention belongs to the protection scope of the technical solution of the present invention.

Claims

1. Use of tryptophan in the preparation of a feed additive for improving the reproductive performance, antioxidant capacity and / or immunity of mammals; in, The reproductive performance includes one or more of average litter weight at birth, average litter weight at weaning, birth survival rate, and weaning survival rate; improving antioxidant capacity and / or immunity includes reducing serum malondialdehyde content, increasing superoxide dismutase level, and increasing total antioxidant capacity level; Wherein, tryptophan is added to the feed of a pregnant mammal, the tryptophan is added in the early and / or late pregnancy, the mammal is a pregnant sow, and the daily dose of tryptophan is 3-6 g / day.

2. A method for improving the reproductive performance of mammals, characterized in that: Adding tryptophan to the feed of pregnant mammals; wherein the tryptophan is added in the early and / or late pregnancy; Wherein, the reproductive performance includes one or more of average litter weight at birth, average litter weight at weaning, birth survival rate, and weaning survival rate; Wherein, the mammal is a pregnant sow, and the daily dose of tryptophan is 3-6 g / day.

3. The method according to claim 2, characterized in that The added amount of tryptophan is 0.1%-0.2% of the daily diet of mammals.

4. The method according to claim 2, characterized in that: For pregnant sows, tryptophan is supplemented from gestational days 0-14 and / or gestational days 99-114.

5. The method according to claim 2 or 3, characterized in that: The mammal takes tryptophan for 2 to 5 parities.

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