First of all, it is clear that ruminants can be fed urea, which is not illegal. The "Catalogue of Feed Additives (2013 Edition)" (Announcement No. 2045 of the Ministry of Agriculture and Rural Affairs) pointed out that there are 10 kinds of non-protein nitrogen that can be added to ruminant feed, namely urea, ammonium bicarbonate, ammonium sulfate, liquid ammonia, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, isobutyl diurea, urea phosphate, ammonium chloride, ammonia, of which urea is the most commonly used non-protein nitrogen.
Ruminants can utilize non-protein nitrourea, mainly by rumen microorganisms. After urea enters the rumen, it is hydrolyzed into ammonia by urease in the rumen. Ammonia is used by microorganisms to synthesize bacterial proteins, which are transferred to the back of the digestive tract with food, broken down by proteases in the true stomach and small intestine, and absorbed by the small intestine.
Although a single microorganism is extremely small and contains very little protein, it cannot support the large number of microorganisms, and 60%-85% of the protein ** of ruminants is provided by bacterial protein.
Dahua over the rumen, nutrition is not wasted, ruminant core nutrition technology optimization expert. When we use ordinary urea, there are two very critical operating points:
1.Urea should not be added in large quantities suddenly, but should be done gradually.
2.Do not drink water immediately after urea feeding.
Why are these two operations strictly forbidden? Let's first understand the two major conditions for rumen microorganisms to synthesize bacterial proteins: one is energy, and the other is nitrogen source. The energy mainly comes from volatile fatty acids produced by the fermentation of rumen microorganisms; The nitrogen source is ammonia produced by urease to break down urea.
Hundreds of millions of rumen microorganisms use energy (volatile fatty acids) and nitrogen (ammonia) to synthesize bacterial proteins, and the two prohibited operations above upset this balance.
Sudden addition of a large amount of urea will cause a short-term surge in ammonia in the rumen; Water will greatly increase the rate of urea release, and it will also allow ammonia to implode in the rumen for a short time.
Too much ammonia cannot be matched with energy and cannot be turned into bacterial protein, which will accumulate in the rumen, absorb with the rumen wall, enter the blood circulation, and be excreted with urine, resulting in waste; When blood ammonia exceeds the safe value, it can cause ammonia poisoning in ruminants.
Slow-release urea is a highly efficient non-protein nitrogen, which can slowly release ammonia in the rumen after feeding, thereby reducing the peak concentration of ammonia in the rumen, promoting the synchronous release of energy nitrogen, and ensuring the full use of ammonia by rumen microorganisms, thereby reducing the accumulation, waste and toxicity of ammonia.
The sustained-release rumen technique is very different from the rumen technique, which requires the coated components to be released smoothly and completely within the required time. The rumen technique, on the other hand, ensures that the coated active ingredient is released and absorbed through the rumen as much as possible in the small intestine.
Therefore, the sustained-release urea also has a high demand for the production process. How to calculate the crude protein of urea? Taking 85% slow-release urea as an example, the content of urea in 1kg is 850g, and the nitrogen content of urea is about 46%, 850g*0467≈400g
For every 1 kg of crude protein, the nitrogen content is about 16%, 400g 016 2500g of crude protein, so 1 kg of rumen slow-release urea, is equivalent to 25kg of crude protein, 1 kg of soybean meal with 42% protein content, the protein is 420g, 2500g 420g 6, which is theoretically equivalent to 1 kg of rumen slow-release urea, which can replace 6 kg of soybean meal in feed.
The amount of slow-release urea added is also related to the energy level in the feed, because the synthesis of rumen bacteria protein requires rumen nitrogen source supply on the one hand, and energy supply on the other hand. Non-protein nitrogen