Cottonseed protein feed formula and application of cottonseed protein feed formula to weaned piglets

Abstract

The invention relates to the technical field of biological feeds, and particularly provides a cottonseed protein feed formula and application of the cottonseed protein feed formula to weaned pigs.The cottonseed protein feed formula comprises cottonseed protein, soybean protein concentrate and fish meal, the content of crude protein of the cottonseed protein is not lower than 60%, and the content of arginine of the cottonseed protein is not lower than 8%; protein degradation rates of cottonseed protein, soybean protein concentrate and fish meal at different time points are measured through an in-vitro bionic digestion technology, and the weaned piglet feed capable of promoting growth of weaned piglets and reducing feed cost is prepared based on the protein degradation rates of the three feed formulas. The cottonseed protein of which the protein digestion rate is higher than that of fish meal and soybean protein concentrate is used for preparing the weaned piglet feed, so that the piglet feed utilization efficiency can be improved, and the serum urea nitrogen level can be reduced.

Description

Technical Field

[0001] The invention relates to the technical field of biological feed, in particular to a cottonseed protein feed formula and application thereof on weaned piglets. Background Art

[0002] The implementation of ultra-early weaning measures for piglets is one of the key technologies in the intensive pig production process. However, after early weaning, piglets are subjected to environmental, psychological and nutritional stresses that damage the intestinal barrier development and microecological environment to varying degrees, which in turn leads to decreased appetite, indigestion and diarrhea, and even death. Therefore, alleviating the intestinal barrier damage caused by weaning stress in piglet production is an urgent task to be solved, which is of great significance to ensure the healthy and sustainable development of my country's pig industry. Taking into account the immature development of the digestive and immune systems of weaned piglets, the actual pig production process mainly uses easily digestible high-grade protein feed to increase protein digestibility and reduce the amount of protein fermented by intestinal microorganisms. At present, the commonly used high-grade protein raw materials are mainly soy protein concentrate and fish meal. However, my country's feed soybeans and fish meal are mainly imported and expensive, and it is urgent to seek domestic feed resources that can replace soy protein concentrate and fish meal.

[0003] my country is one of the major cotton-growing countries, with abundant resources of cottonseed and other processing byproducts, and an annual cottonseed production of about 8 million tons. Cottonseed meal is an important protein feed formula in my country, with a crude protein content of about 40%, slightly lower than soybean meal, and has the potential to partially replace soybean meal. However, cottonseed meal contains a large amount of anti-nutritional factors such as free gossypol and cyclopropene fatty acids, which limits its application in animal husbandry production. Through the innovative development of cottonseed processing technology, cottonseed protein raw materials have emerged, which have the characteristics of low anti-nutritional factors, high protein content, and high arginine content. The crude protein and arginine content of cottonseed protein can be as high as 60% and 8%. In addition, cottonseed protein generates many small peptides during processing, and some small peptides have the effect of inhibiting the activity of pathogens, while playing the role of antioxidant, antihypertensive, anticancer and immunomodulatory functions. Therefore, cottonseed protein can not only provide rich feed protein, but also generate many functional substances that regulate host health during its preparation process.

[0004] In addition, accurate evaluation of the nutritional value of protein feed formula and accurate formulation of feed are the basis for efficient utilization of carbon and nitrogen nutrients. At present, the evaluation of the nutritional value of feed formula protein is mainly based on the determination of nutritional parameters such as standard terminal ileal amino acid digestibility. However, the digestible amino acid content can not only reflect the dynamic changes in the digestion and utilization of feed protein and amino acids in the pig intestine, but the digestion rate of carbon and nitrogen nutrients affects the conversion and deposition efficiency of protein. According to the different digestion rates, proteins can be divided into fast-digesting proteins, slow-digesting proteins and resistant proteins. In recent years, the relevant research on cottonseed protein in growing pigs and weaned piglets has gradually increased. A large number of studies have confirmed that the use of appropriate amounts of cottonseed protein to replace soybean meal and soy protein concentrate in pig feed has no adverse effects on pig growth performance, indicating that cottonseed protein can effectively replace soy protein to a certain extent. Although the protein digestibility of cottonseed protein, soy protein concentrate and fish meal is basically the same, the protein and amino acid digestion rates among the three and the application results in weaned piglets are still unclear. The invention compares the in vitro degradation rate and small peptide molecular weight of crude protein in cottonseed protein, soybean protein concentrate and fish meal to evaluate the protein quality of the three; and provides a cottonseed protein feed which can improve the feed utilization efficiency and nutrient digestibility of weaned piglets and reduce the serum urea nitrogen level. Summary of the invention

[0005] The invention provides a cottonseed protein feed formula and application thereof to weaned piglets, so as to improve the feed utilization efficiency of weaned piglets, reduce the serum urea nitrogen content, and reduce the feed cost.

[0006] In a first aspect, the present invention provides a cottonseed protein feed formula, comprising cottonseed protein, soybean protein concentrate and fish meal, wherein the feed formula is in an air-dried state, wherein the crude protein and arginine contents of the cottonseed protein are not less than 60% and 8%.

[0007] Preferably, the crude protein and arginine contents of the cottonseed protein are 60.56% and 8.02%, respectively.

[0008] Preferably, the ratio of the cottonseed protein, the soybean protein concentrate and the fish meal in the mixed feed is 1:1:0.7.

[0009] In a second aspect, the present invention provides a weaned piglet feed comprising a cottonseed protein feed formula, wherein the addition ratio of the cottonseed protein feed formula is 5%.

[0010] In a third aspect, the present invention provides an application of the cottonseed protein feed formula or the weaned piglet feed in improving the growth performance of weaned piglets.

[0011] In a fourth aspect, the present invention provides an application of the cottonseed protein feed formula or the weaned piglet feed in influencing the digestibility of nutrients in weaned piglets.

[0012] In a fifth aspect, the present invention provides an application of the cottonseed protein feed formula or the weaned piglet feed in reducing the urea nitrogen content in the blood of weaned piglets.

[0013] The beneficial effects of the present invention are: The invention provides a cottonseed protein feed formula, comprising cottonseed protein, soybean protein concentrate and fish meal, wherein the crude protein and arginine contents of the cottonseed protein are not less than 60% and 8%, respectively, and the protein degradation rates of the cottonseed protein, soybean protein concentrate and fish meal at different time points are determined by in vitro bionic digestion technology, and a feed that can promote the growth of weaned piglets and reduce feed costs is prepared based on the protein degradation rates of the three feed formulas. The cottonseed protein having a faster protein digestion rate than fish meal and soybean protein concentrate is used to prepare weaned piglet feed, which can improve the piglet feed utilization efficiency and reduce the serum urea nitrogen level. DETAILED DESCRIPTION

[0014] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the attached table of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0015] Example 1 In vitro bionic digestion technology was used to determine the protein degradation rates of cottonseed protein, soybean protein concentrate and fish meal at different time points 1. In vitro biomimetic digestion 1. Pretreatment of cottonseed protein, soybean protein concentrate and fish meal Cottonseed protein, soy protein concentrate and fish meal were ground using a hammer mill with a 1 mm screen.

[0016] 2. In vitro bionic digestion process (1) System setup: A two-step in vitro digestion simulation was used for amplification and improvement. Six replicates were set up for each sample in the gastric and intestinal stages for simulated incubation, and each replicate was performed in a 500 mL reaction bottle. (2) Simulated oral digestion: After adding 5 g of the feed formula sample to the reaction bottle of each replicate group, 16 mL of 2.5 mg / mL salivary α-amylase (pH = 7.0) was added and incubated at a constant speed (220 rpm) in a constant temperature air bath shaker (39°C) for 5 min to simulate oral digestion; (3) Simulated gastric digestion: Transfer to 0.1 M phosphate buffer (volume 250 mL, pH = 6.0) and 1 M HCl solution (15 mL) at 39°C, and adjust the pH to 3.5 with 1 M HCl or 1 M NaOH. Add freshly prepared 10 mg / mL pepsin solution (8 mL), cover each replicate reaction bottle with a plastic cap, and place it in a constant temperature air bath shaker (39°C) for constant rate agitation (220 rpm) and incubate for 120 minutes; (4) Simulated small intestinal digestion: After the gastric phase incubation, an in vitro simulated incubation in the small intestine phase was performed. 60 mL of phosphate buffer (0.2 M, pH = 6.8) and 10 mL of 2.5 M NaOH were added to each replicate group, and the pH was adjusted to 6.8 with 1 M HCl or 1 MNaOH to simulate the digestive environment in the small intestine. 0.1 g / mL amyloglucosidase and 100 mg / mL pancreatic enzyme mixture (60 mL) and 20 mL of 150 mg / mL bile solution were added. Incubation was continued at a constant stirring rate (220 rpm) in a constant temperature air bath shaker (39°C). An equal amount of 5 mL of the digestion mixture was drawn using a customized disposable syringe at 0, 30, 120, 150, 180, 150, 210, and 240 minutes. In order to correct the nitrogen content of the added enzyme, blank groups without protein sources were analyzed separately (6 replicates in the gastric phase and the small intestine phase); (5) The digestion mixture samples collected during the continuous incubation were terminated by enzymatic hydrolysis in liquid nitrogen, and 2 mL of the digestion mixture sample was taken out and placed at -20°C for inspection. In addition, an additional 2 mL of the digestion mixture sample was taken out and centrifuged at 12,000 rpm for 10 min at 4°C, and the supernatant was prepared and placed at -20°C for inspection.

[0017] 4. Chemical analysis The dry matter (DM), crude protein (CP), crude fat (EE), ash (Ash), 18 kinds of amino acids, neutral detergent fiber and acid detergent fiber of cottonseed protein were determined according to GB / T 6435-2006, GB / T 6432-2018, GB / T 6433-2006, GB / T 6438-2007, GB / T 18246-2019, GB / T 20806-2022 and NY / T 1459-2007, respectively. The total energy was determined according to the international standard ISO 9831:1998. The crude protein content in the mixed solution of cottonseed protein, soybean protein concentrate and fish meal digestion was determined according to GB / T 6432-2018, and the molecular weight of small peptides in the supernatant of cottonseed protein, soybean protein concentrate and fish meal digestion for 20 min and 240 min in vitro was determined by liquid chromatography.

[0018]

[0019] 5. Data Analysis The data were analyzed by variance analysis using SAS 9.2 statistical software Proc GLM, the LSMEANS method was used to calculate the mean values ​​of the treatment groups, and multiple comparisons were performed using Tukey's test procedure. The protein digestibility data were analyzed with each digestive tract as the statistical unit. The statistical results were considered significant when P<0.05, and a trend of difference when 0.05≤P<0.10.

[0020] 2. In vitro bionic digestion results The changes in the in vitro degradation rates of cottonseed protein, soybean protein concentrate and fish meal crude protein at different bionic digestion time points in this example are shown in Table 2. The results show that starting from the 30th minute of the in vitro bionic digestion small intestine stage, the protein degradation rate of cottonseed protein was significantly higher than that of fish meal and soybean protein concentrate (P<0.05). The proteins degraded in the in vitro bionic digestion small intestine stage at 0-30min, 30-240 min and >240 min were defined as fast digestible protein, slow digestible protein and resistant protein, respectively. The results showed that the fast digestible protein content of cottonseed protein was significantly higher than that of fish meal and soybean protein concentrate, while the slow digestible protein content of cottonseed protein was significantly lower than that of fish meal and soybean protein concentrate, and there was no significant difference in the resistant protein content of the three. The molecular weight composition of small peptides of cottonseed protein, soybean protein concentrate and fish meal crude protein in vitro bionic digestion is shown in Table 3. The results show that there is no significant difference in the proportion of each molecular weight of small peptides of soybean protein concentrate and fish meal crude protein in vitro bionic digestion. However, after 240 min of in vitro bionic digestion, the proportion of small peptides with a molecular weight range of 0-2 kDa in the cottonseed protein digestate was 55.10%, which was 3.63% and 3.11% higher than that of fish meal and soy protein concentrate, respectively.

[0021]

[0022]

[0023] Example 2 Effects of cottonseed protein replacing soybean protein concentrate and fish meal on growth performance, nutrient digestibility and blood biochemistry in weaned piglets 1. Test methods A total of 192 healthy Durbin × Chang × Dacheng hybrid weaned piglets with an initial body weight (BW) of 7.8 ± 0.2 kg (weaned at 28 days of age) were selected and randomly divided into 4 groups. They were fed with 10% soybean protein concentrate, 5% soybean protein concentrate + 5% cottonseed protein, 10% cottonseed protein and 3.5% fish meal, respectively. The composition of the feed formula of each group is shown in Table 4. Each dietary treatment group had 6 replicates, and each replicate had 8 pigs. The experimental period was 28 days. According to the Chinese Guidelines for Pig Nutrient Requirements (2020), weaned piglets were provided with a mixed premix of trace minerals and vitamins to meet the recommended nutritional requirements of pigs.

[0024]

[0025] 2. Feeding and Management During the experiment, all experimental pigs were kept in fences (1.5 m×1.2 m×0.8 m) and had free access to food and water. The pig house was disinfected and cleaned every afternoon, and the humidity and temperature were controlled at 50%-60% and 25℃-28℃, respectively. The pig farm feeding and management system was strictly followed, and the pigs' feeding, feces, and mental state were observed every day.

[0026] 3. Testing indicators 1. At the beginning and end of the experiment, the body weight (BW) and feed consumed by the piglets were weighed to calculate the average daily feed intake (ADFI) and average daily gain (ADG). The feed conversion rate (F / G) of the piglets was calculated as the ratio of ADFI to ADG.

[0027] 2. Digestibility of nutrients in feed The formula for calculating the apparent total intestinal digestibility of nutrients in piglets is as follows: Apparent total tract digestibility (%) = 100 – (concentration of hydrochloric acid insoluble ash in feed × nutrient content in feces / content of hydrochloric acid insoluble ash in feces × nutrient content in feed) × 100 3. Blood biochemistry.

[0028] The serum albumin (ALB), total protein (TP), serum urea nitrogen (BUN), and the activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) were determined by an automatic biochemical analyzer (Hitachi 7600, Japan).

[0029] 4. Data Analysis The data were analyzed by variance analysis using SAS 9.2 statistical software Proc GLM, the mean values ​​of the treatment groups were calculated using the LSMEANS method, and multiple comparisons were performed using the Tukey's test procedure. The growth performance, nutrient digestibility, and blood biochemical data were analyzed using the column as the statistical unit. The statistical results were considered significant when P<0.05, and a trend of difference when 0.05≤P<0.10.

[0030] V. Test Results 1. Growth performance: As shown in Table 5, there were no significant differences in the average daily feed intake and average daily weight gain of weaned piglets in the four dietary treatment groups of this experiment. However, compared with the three dietary treatment groups of basal diet, 100% soy protein concentrate replacement and 100% fish meal replacement, the feed-to-weight ratio of weaned piglets in the 50% soy protein concentrate replacement diet treatment group was significantly reduced (P<0.05).

[0031]

[0032] 2. Nutrient digestibility: As shown in Table 6, there were significant differences in the apparent total tract digestibility of dry matter, crude protein and gross energy in the four dietary treatment groups. The use of cottonseed protein to completely replace soybean protein concentrate significantly reduced the apparent total tract digestibility of dry matter, crude protein and gross energy in the feed (P<0.05).

[0033]

[0034] 3. Blood biochemical indexes: As shown in Table 7, there were significant differences in the content of serum urea nitrogen in the four dietary treatment groups. Substituting 50% of soybean protein concentrate with cottonseed protein significantly reduced the level of serum urea nitrogen in piglets (P<0.05).

[0035]

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A cottonseed protein feed formula, characterized in that: The feed formula comprises cottonseed protein, soybean concentrated protein and fish meal. In the air-dried state, the crude protein and arginine contents of the cottonseed protein are not less than 60% and 8%.

2. The cottonseed protein feed formula according to claim 1, characterized in that: The crude protein and arginine contents of the cottonseed protein are 60.56% and 8.02% respectively.

3. The cottonseed protein feed formula according to claim 1, characterized in that: The ratio of the cottonseed protein, the soybean protein concentrate and the fish meal in the mixed feed is 1:1:0.

7.

4. A weaned piglet feed, characterized in that: A cottonseed protein feed formula comprising any one of claims 1 to 3, wherein the addition ratio of the cottonseed protein feed formula is 5%.

5. Use of the cottonseed protein feed formula according to any one of claims 1 to 3 or the weaned piglet feed according to claim 4 in improving the growth performance of weaned piglets.

6. Use of the cottonseed protein feed formula according to any one of claims 1 to 3 or the weaned piglet feed according to claim 4 in influencing the digestibility of nutrients in weaned piglets.

7. Use of the cottonseed protein feed formula according to any one of claims 1 to 3 or the weaned piglet feed according to claim 4 in reducing the urea nitrogen content in the blood of weaned piglets.

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