Application of urea in ruminants.
Non-protein nitrogen feed refers to the general term for urea, bicosal and certain amine salts. They are simple nitrogen-containing compounds synthesized by chemicals and do not provide energy. According to the metabolic characteristics of ruminants, its nutritional effect is mainly as a nitrogen source for the synthesis of protein by tumor stomach microorganisms, thus playing a nutritional role in supplementing protein and saving protein feed.
(1) Urea.
Urea is cheap, contains up to 46% nitrogen, and is equivalent to 2.8 kg of crude protein per kg of urea, or 7 kg of crude protein content of soy cake. Experiments show that replacing protein feed in cattle and sheep with the right amount of urea not only reduces costs, but also increases productivity.
Urea is mainly used in adult ruminants and is not suitable for feeding yaks and lambs that have not yet fully developed tumor stomachs. When adding urea, it is necessary to pay attention to: the supply of sufficient amounts of soluble carbohydrates to provide energy for the stomach microorganisms, the daily grain contains a certain amount of protein, tests proved that the daily grain crude protein content of 11% to 12%, urea utilization effect is best, the supply of the right amount of and balanced minerals, including calcium, magnesium and trace elements cobalt, zinc, etc., to ensure the supply of moderate vitamins, especially vitamin A, D.
Urea degrades and releases ammonia quickly in the stomach, and improper use can lead to poisoning. For this reason, special attention should be paid to feeding doses and methods. For middle-class cows, young cows and growing cattle, urea feeding is generally 1% of the dry matter of daily grains, or 2% of the mixture of refined materials, but the content of urea nitrogen does not exceed 25% to 30% of the total nitrogen content of daily grains. Urea should not be replenished for high-yielding cows feeding large quantities of refined material. When feeding urea, the amount should be less to more, so that the tumor stomach microbiome has a period of adaptation time. In the feeding method should be aware that urea should not be fed alone, should be reasonable with other feed, so as not to cause poisoning. Feeding methods are: ammonia straw or adjusted into urea silage (0.3% to 0.5%) feeding, or with syrup into liquid urea essence feeding, or made into urea particles, or made urea lick salt brick for cattle, sheep licking food.
Add 1% to 2% of the whole mixed grain.
