CN114766602B - Preparation and performance testing method of coated tryptophan pellet feed - Google Patents

Abstract

A preparation method of pellet feed and a performance detection method of pellet feed belong to the technical field of feed processing in animal husbandry, and the preparation method comprises the steps of preparing a core material, preparing a wall material, and mixing and coating the core material and the wall material according to a weight ratio to obtain coated tryptophan pellet feed. The performance detection method is a method combining in-vitro simulated digestive tract test and in-vivo nylon bag degradation test. By taking saturated fatty acid as a coating material, tryptophan is physically coated, and by detection, the function and the effect of a tryptophan coated sample are more stable than those of uncoated samples in buffer solutions with different pH values, so that the use effect is better, the utilization of tryptophan by animal organisms is promoted, and when the coated feed enters abomasum and intestinal tracts through rumen, the coated wall material can be effectively decomposed, the function of tryptophan is fully exerted, and the production performance is improved.

Description

Preparation and performance testing method of coated tryptophan pellet feed

Technical field

The invention belongs to the technical field of animal husbandry feed processing, and relates to a method for preparing pellet feed and a method for testing the performance of pellet feed. Specifically, it relates to a method for preparing tryptophan pellet feed using coating technology, and for treating the coated feed. Methods for performance testing.

Background technique

Amino acids include essential amino acids and non-essential amino acids. Essential amino acids include leucine, isoleucine, tryptophan, lysine, methionine, phenylalanine, valine, and threonine. Tryptophan is one of the eight essential amino acids required by humans and animals. It cannot be synthesized by the body itself. Its metabolites are 5-hydroxytryptamine, melatonin, NAD (nicotinamide adenine dinucleotide), NADP and tobacco. Acids are also involved in the regulation of animal feeding, growth, reproduction, immunity, anti-stress and other aspects, and are called important precursor substances. Tryptophan is also an important component of body protein. It can affect animal behavior and reduce stress responses. It can also affect fat metabolism in animals and reduce fat content in animal livers. An appropriate amount of tryptophan will also increase animal feed intake and improve its production performance and feed conversion rate. At present, tryptophan is not only used in the pharmaceutical and food industries, but also gradually has more applications in the feed additive industry.

Han Xufeng et al. used Peking ducks aged 1 to 14 days as the research object. The study found that the level of L-tryptophan addition had a significant impact on the daily feed intake, daily weight gain, and feed-to-weight ratio of Peking ducks (P<0.05), and with increasing As the level of tryptophan increases, the daily feed intake first increases and then decreases. Adding 0.202% L-tryptophan has the best effect. He Qiang et al. used Xinyang green-shell laying hens as the research object. Adding appropriate levels of tryptophan to feeds lacking tryptophan can increase the egg production rate of Xinyang green-shell laying hens and reduce the feed-to-egg ratio. Wang Rongfa and others believe that when the digestible L-tryptophan content in the low-protein diet is 0.146%, the experimental pigs show the best growth performance. It can be seen that increasing the amount of tryptophan can increase the feed intake of poultry and pigs. In research on ruminants, Nolte (2008) found that tryptophan is the third limiting amino acid in growing lambs. Tryptophan deficiency can lead to retarded animal growth, low feed intake, poor stress resistance, and rough coat. A large number of studies have also shown that tryptophan supplementation increases the supply of tryptophan in the small intestine, improves tryptophan deficiency in late-pregnancy dairy cows, increases milk production, increases 5-hydroxytryptamine content in the brain, and promotes PRL, The secretion of hormones such as GH, thereby promoting the secretion of milk.

At present, coating technology is used to protect active substances in feed additives and ensure product consistency and efficiency. It can improve product stability, mask bad odors, control product release in the digestive tract, and improve bioavailability. plays an important role. Amino acid coating technology is mainly focused on ruminants. This is because the rumen of ruminants has a strong fermentation function. After amino acids enter the rumen, they are degraded by rumen microorganisms and cannot be effectively supplied to the body. In order to reduce losses, coating technology is used to process amino acids. However, when tryptophan is ingested by animals as feed, it will quickly take effect in the animal's body. This is because tryptophan is a small molecule nutrient and when it is ingested in large amounts, the animal absorbs and utilizes it. The efficiency will be reduced, and the method of feeding small amounts and multiple times will significantly increase the workload of animal feeding. When tryptophan feed is coated, the greater the proportion of the coating material in the product (the thicker the coating film), the smaller the release rate. When the coating film is too thick, the particle size diameter of the coated product is significantly increased. Large, reducing product release rate in the abomasum and small intestine.

Therefore, how to use coating technology to produce according to the tryptophan content required by the animal itself, effectively slow down the release rate of tryptophan in the animal body, and promote the utilization of tryptophan by the animal body, is of great significance in improving production performance. . The selection of coating materials, the proportion of coating materials in the product, and the detection of coating performance are technical issues that need to be solved urgently in coating technology.

Contents of the invention

The purpose of the present invention is to solve the technical problems existing in the current tryptophan feed coating technology and the deficiencies that occur during the use of the coated feed, and propose a method for preparing and performance testing coated tryptophan pellet feed, based on animal The required tryptophan content is subject to feed coating and performance testing to slow down the release rate of tryptophan in the animal body and further improve the animal's absorption and utilization efficiency.

The technical solution of the present invention: a method for preparing coated tryptophan pellet feed, which is characterized in that the method is as follows:

(1) Prepare core material;

(1-1) Mix tryptophan and water and then perform shot blasting to obtain spherical pellets;

(1-2) Screen the pellet particles according to their particle size;

(1-3) Dry the screened pellet particles to obtain pellet particles with a moisture content of ≤10wt%;

(1-4) Fluidize the dried pellet particles to obtain the required core material;

(2) Prepare wall materials;

(2-1) Melt saturated fatty acids;

(2-2) Cool the melted saturated fatty acid to obtain the required wall material;

(3) Mix and coat the core material and wall material according to the weight ratio to obtain coated tryptophan pellet feed.

Further, the particle size value of the particle size described in step (1-2) is 1.5 to 8 mm.

Further, the drying temperature of the drying process described in step (1-3) is 50-70°C, and the drying time is 50-80 minutes.

Further, the fluidization treatment described in step (1-4) adopts fluidized bed fluidization. The wind pressure of the fluidized bed is 0.012~0.024MPa, the rotation speed is 90~100r/min, and the inlet air temperature is 35~45 ℃, the outlet temperature is 25 ~ 35 ℃.

Further, the saturated fatty acid in step (2-1) is any one of C16-C18 fatty acid, glyceryl monostearate, hydrogenated fatty acid and fatty alcohol, and the melting temperature of the saturated fatty acid is 65-80°C.

Further, the cooling temperature of the saturated fatty acid in step (2-2) is 50-55°C.

Further, the weight ratio of the core material and wall material described in step (3) is 1:1 to 1:2.

A method for testing the performance of coated tryptophan pellet feed, which is characterized in that: the testing method is a combination of in vitro simulated digestive tract test + in vivo nylon bag degradation test.

Further, the in vitro simulated digestive tract test method described in step (8) is as follows:

Prepare buffers with different pH values, and use test groups with different tryptophan mass percentages and uncoated tryptophan as the control group. Place the test group and control group at the bottom of a 50 ml stoppered test tube, and add 20 ml of buffer. , cap the test tube plug tightly; digest it in a constant temperature water bath shaker at 39°C, take it out, rinse and filter, dilute the filtrate to volume, measure the tryptophan content in the filtrate, and finally calculate the rumen passage rate of tryptophan.

Further, the in vivo nylon bag degradation test method described in step (8) is as follows:

Three cows with fistulas were prepared. The coated tryptophan was used as the test group, and the uncoated tryptophan was used as the control group. The nylon bags containing the tryptophan-coated preparation were put into the rumen fistula of the cows in batches. Take out a net bag from the rumen of each cow during this period, wash it with water, dry it in a constant temperature oven to a constant weight, cool it and weigh it, and calculate the protection rate of the tryptophan compound in the rumen.

The beneficial effects of the present invention are: the preparation and performance testing method of coated tryptophan pellet feed proposed by the present invention. The preparation method is: preparing the core material, preparing the wall material, and mixing the core material and the wall material according to the weight ratio. was, to obtain coated tryptophan pellet feed. The performance testing method is: in vitro simulated digestive tract test + in vivo nylon bag degradation test. By using saturated fatty acids as coating materials, tryptophan is physically coated. Through testing, in buffers with different pH values, the functions and effects of tryptophan-coated samples are more stable than uncoated samples. Use The effect is better and promotes the utilization of tryptophan by the animal body. When the coated feed passes through the rumen and enters the abomasum and intestines, the coating wall material can be effectively decomposed, giving full play to the functional role of tryptophan and improving improve production performance.

Description of the drawings

Figure 1 is a flow chart for the preparation of tryptophan-coated particles in the present invention.

Figure 2 is a flow chart for preparing in vitro simulated digestive tract reagents in the present invention.

Detailed ways

The present invention will be further clarified below in conjunction with the appendix and specific embodiments. It should be understood that these embodiments are only used to illustrate the patent of the present invention and are not intended to limit the scope of the patent of the present invention. After reading the patent of the present invention, those skilled in the art will have a clear understanding of the present invention. Modifications of various equivalent forms of the patent fall within the scope defined by the appended claims of this application.

Example 1

A method for preparing coated tryptophan pellet feed, including the following steps:

Step 1: Core material preparation

Mix 30kg L-tryptophan and 1kg water and then perform shot blasting to 1.5mm spherical particles.

Step 2: Mix and dry

The drying temperature is 50°C, and the dried tryptophan pellets are obtained after drying for 80 minutes until the moisture content is ≤10wt%.

Step 3: Streaming

Pour the dried tryptophan pellets into the storage tank of the fluidized bed, adjust the fluidized bed wind pressure to 0.01MPa, the rotation speed to 90r/min, the inlet air temperature to 35°C, and the outlet air temperature to 25°C.

Step 4: Preparing wall materials

After melting 30kg of C16-C18 fatty acid, cool it to 55℃.

Step 5: Wrapping

Mix the core material and wall material with a weight ratio of 1:1 to obtain coated tryptophan particles.

Example 2

Different from the above embodiment 1, a method for preparing coated tryptophan pellet feed includes the following steps:

Step 1: Core material preparation

Mix 30kg L-tryptophan and 1kg water and perform shot blasting to obtain 3mm spherical particles.

Step 2: Sieve

Remove spherical particles with a diameter less than 3mm.

Step 3: Mix and dry

The drying temperature is 70°C and dried for 50 minutes until the moisture content is ≤10wt% to obtain dried tryptophan pellets.

Step 4: Streaming

Pour the dried tryptophan pellets into the storage tank of the fluidized bed, adjust the fluidized bed wind pressure to 0.024MPa, the rotation speed to 100r/min, the inlet air temperature to 45°C, and the outlet air temperature to 35°C.

Step 5: Preparing wall materials

After melting 60kg of hydrogenated fatty acid, cool to 50°C.

Step 6: Wrapping

Mix the core material and wall material with a weight ratio of 1:2 to obtain coated tryptophan particles.

Example 3

A method for testing the performance of coated tryptophan pellet feed, using an in vitro simulated digestive tract test. The specific operation method is as follows:

Step 1: Test Materials

A buffer with a pH value of 6.6 and a buffer with a pH value of 2.4. The buffer with a pH value of 6.6 is used to simulate the rumen environment of ruminants, and the buffer with a pH value of 2.4 is used to simulate the duodenal environment of ruminants. Coated tryptophan samples A and B, in which the mass percentages of tryptophan are 30% and 45% respectively, and uncoated tryptophan sample C.

Step 2: Test Method

For stability testing in buffers with different pH values, use uncoated tryptophan as the control group. Weigh 1g each of samples A, B, and C, place it at the bottom of a 50ml stoppered test tube, add 20ml buffer, and cover the test tube tightly. Plug; Digest for 2h, 4h, 8h, 12h and 24h in a constant temperature water bath shaker at 39°C; rinse and filter after taking out, dilute the filtrate to volume, measure the tryptophan content in the filtrate, and calculate the rumen passage rate of tryptophan .

Result analysis:

(1) The rumen passage rate of each sample at different time points is shown in Table 1.

Table 1 Rumen passing rate (%) of each product at different time points when the pH value is 6.6

(2) The small intestinal release rate of each sample at different time points is shown in Table 2.

Table 2 Small intestinal release rate (%) of each product at different time points when the pH value is 2.4

It can be seen from the test data that in the buffer solution with a pH value of 6.6 and the buffer solution with a pH value of 2.4, the rumen passage rate effect of each test product is: Sample B>Sample A>Sample C. The sample coated with tryptophan is more stable than the uncoated sample, indicating that the effect of coating tryptophan is better. Sample C that is not coated may be completely digested in the rumen and cannot reach the small intestine.

Example 4

A method for testing the performance of coated tryptophan pellet feed, using an in vivo nylon bag degradation test. The specific operation method is as follows:

Step 1: Test Materials

Select three fistula cows as experimental animals. The animals have good growth, health, and the breed, strain, age, gender, weight, etc. should be consistent. Coating tryptophan sample, nylon bag: Choose 300 mesh polyester cloth to make a 50×30mm nylon bag. Weigh about 2g of the sample into a nylon bag and record its mass as m. Seal, weigh again as m1, and number.

Step 2: Test Method

Select three fistula cows on a certain farm. The animals are growing well, healthy, and should be consistent in breed, strain, age, gender, weight, etc. Nylon bags containing about 2.0g of tryptophan-coated preparation were put into the rumen fistula of dairy cows in batches, and were taken out from the rumen of each cow at each time point at 1.5, 3, 6, 12, 18, and 24 hours. A net bag, washed with clean water, then dried in a constant temperature oven at 65°C to a constant weight (8 hours), weighed after cooling, and the release rate of the tryptophan complex in the rumen and duodenum was calculated to detect the bag. Stability of tryptophan.

Result analysis:

The release rate of coated tryptophan in the rumen and duodenum is shown in Table 3.

Table 3 Release rate of coated tryptophan in rumen and duodenum

1.5h 3h 6h 12h 18h 24h Rumen (%) 2 15.45 24.96 43.66 72.75 75.88 Duodenum(%) / / 84.66 86.43 90.29 95.66

It can be seen from the experimental data that the stability of coated tryptophan in the rumen decreases with time. The release rate of coated tryptophan in the duodenum increased with time, and the release rate at each time point was higher. The release rate can reach more than 84%, which shows that the coated tryptophan product has good digestibility in duodenal fluid.

This test uses the detection method of in vitro simulated digestive tract and in vivo nylon bag degradation test to obtain a more stable function and effect of coated tryptophan.

Claims (1)

1. A preparation method of coated tryptophan pellet feed, which is characterized by comprising the following steps:

(1) Preparing a core material;

(1-1) mixing tryptophan with water, and performing shot blasting treatment to obtain spherical pellet particles;

(1-2) sieving the pellet particles according to the particle size of 1.5-8 mm;

(1-3) drying the screened pellet particles to obtain pellet particles with the water content less than or equal to 10wt%;

(1-4) fluidization treatment is carried out on the dried pellet particles to obtain a required core material;

(2) Preparing a wall material;

(2-1) melting saturated fatty acid at 65-80 ℃;

(2-2) cooling the melted saturated fatty acid to 50-55 ℃ to obtain a required wall material;

(3) And mixing and coating the core material and the wall material according to the weight ratio of 1:1 to obtain the coated tryptophan pellet feed.