Extrusion Processing Method of Corn Urea Protein——SUNSHINE Industry

Ruminants such as cattle and sheep can use non-protein nitrogen (such as urea) to convert into animal protein. The nitrogen content of urea is 46%, which is about 280% or more when converted into crude protein, that is, 1 kg of urea is equivalent to the protein content of 6 kg of soybean meal. Since the 1960s, cheap urea products have been widely added to ruminant feeds to supplement concentrates instead of protein feeds such as soybean meal, achieving better benefits. my country has abundant corn resources and a large output of urea. Using extrusion technology to develop non-protein nitrogen (NPN) as a protein feed for cattle and sheep is an effective method with low investment and quick results.

1. Basic Principles

After urea enters the rumen, it is decomposed into ammonia and carbon dioxide under the action of urease. Rumen microorganisms use ammonia to synthesize bacterial protein, which enters the true stomach and small intestine for digestion and absorption. Bacterial protein has a high biological value. The amino acids it provides account for 40% to 70% of the total amount absorbed by the abomasum and small intestine. The composition of amino acids is similar to that of the body and is easy to digest and absorb. However, if too much urea is consumed, ammonia is released too quickly and in too much amount in the rumen. The release rate exceeds the utilization rate of microorganisms and enters the body through the body's urea cycle, resulting in excessive blood ammonia and easy ammonia poisoning. Therefore, when using urea as a nitrogen source, the first is to add an appropriate amount, and the second is to pretreat the urea to slow down the release rate of urea in the rumen and control the activity of urease.

2. Disadvantages of direct feeding of urea:

(1) Poor palatability:

Urea is extremely bitter, and cattle and sheep do not like to eat it, which affects the feed intake and has a side effect.

(2) Low absorption and utilization rate:

After entering the rumen, urea is decomposed into ammonia and carbon dioxide. Part of the ammonia is used by rumen microorganisms to synthesize bacterial protein, which enters the abomasum for digestion and absorption. Since the release of ammonia is very fast, microorganisms do not have time to synthesize all of it into bacterial proteins. A relatively small part enters the blood and is finally excreted into the urine and wasted. Therefore, although some people feed urea directly, cattle and sheep still do not grow fast.

(3) Poisoning:

When the ammonia level in the blood exceeds the burden threshold of the liver, it will cause a cumulative increase in the blood ammonia concentration. When it reaches a certain level, it will cause poisoning or even death of ruminants.

It can be seen that direct feeding of urea is not controllable, which also affects the application of urea in ruminant feeding. One of the effective ways to solve this problem is to use puffing to generate gelatinized starch urea.

3. The advantages of corn urea puffing processing

Urea is mixed evenly with high-starch grains (such as corn, etc.) and additives in a certain proportion and then put into the puffing machine for puffing. After puffing, the mixed powder makes the urea evenly adsorbed in the corn starch tissue, forming a physical bond by gelatinization, and some reducing sugars and urea form a chemical bond, and a small amount of urea molecules produce a diuret reaction. After ruminants eat this feed, urea is released slowly and evenly. Urease inhibitors can inhibit the activity of urease, slowing down the release of ammonia, making it safe and effective.

In recent years, some professional feed factories (especially in pastoral areas) have begun to produce gelatinized urea. Some of them have added rumen regulators and natural growth promoters to their products to further improve the utilization rate of urea, and called them (urea) composite proteins. Composite proteins are mainly composed of corn, soybeans, urea, rumen regulators and natural growth promoters, with an average protein content of 75%.

The main advantages of using gelatinized urea composite protein are:

(1) Good palatability:

After gelatinization, natural plant growth promoters, corn starch, urea, and soybeans produce dextrin and sugar, becoming fragrant, sweet and sour, and improving palatability. (2) Slowing down the rate of ammonia release:

The rate of ammonia release from gelatinized starch and urea in the rumen is slowed down. With the effect of rumen regulators, the release rates of corn starch and ammonia are basically synchronized, which can synthesize a large amount of bacterial protein. The ammonia level in the rumen is reduced by 1/3 compared with direct feeding of corn urea, and the bacterial protein is more than doubled, which increases the digestion and absorption rate of crude fiber by 15%-20%.

(3) Due to the high digestion and absorption rate of puffed corn, the utilization rate of puffed corn urea by rumen microorganisms is relatively high, reaching more than 85%.

(4) Fast weight gain and high milk production:

Due to the use of starch and protein rumen protection technology, the degradation in the rumen is reduced and the utilization rate is improved. According to the test, it can increase blood sugar concentration by about 12%, serum total nitrogen by about 20%, increase milk production of dairy cows by more than 10%, and increase weight of beef cattle and sheep by more than 20%. 

(5) Enhanced disease resistance of livestock:

The high temperature and high pressure during the puffing process not only passivates anti-nutritional factors, but also sterilizes the feed, reducing the chance of livestock contracting diseases. At the same time, due to the appropriate ratio of proteins with different degradation rates, the ammonia in urea has the effect of destroying the unstable alkaline bond between lignin and fiber. The natural growth promoter has the function of increasing feeding and promoting digestion, which can increase the ruminant's intake of hay and enhance the disease resistance of livestock.

(6) Low cost:

Each ton of compound protein can replace 1.7 tons of soybean meal, 1 ton of corn or 2 tons of concentrated feed, reducing feed costs by 20-40%. After using compound protein, breeders can use a large amount of hay with low protein content, broaden the source of roughage, reduce feeding costs, and increase weight gain. Each beef cattle can increase net income by more than 1,000 yuan.

IV. Usage and precautions of corn urea protein:

(1) It is suitable for feeding all ruminants with mature rumen. It cannot be used for young animals (less than six months old) whose rumen has not yet matured.

(2) To prevent stress from feed change, the feeding amount should be increased from small to large, and generally all adaptation can be achieved in 10-15 days.

(3) In feeds with a total protein content of less than 12%, based on the original formula, the feed formula should be adjusted and added according to the amount of protein in feeds with a protein content of more than 12%, and the expanded urea should be used to replace 1/3 of the protein. Feeding amount: 65% protein expanded urea feed, 5% premix, an average of 400-600 grams per cow per day, 50 grams per sheep, which can replace 1.5 times the soybean meal.