Most of the diets in pig farms are corn and soybean meal-type diets, but the amino acids contained in corn and soybean meal cannot meet the needs of pigs, and lack of essential amino acids reduces protein synthesis in pigs, resulting in a series of problems in protein metabolism and related enzyme synthesis in the body are mainly manifested as growth retardation and even lead to metabolic diseases. Therefore, it is very necessary to add lysine to the feed.
Lysine can not only improve the utilization rate of feed, but also increase the immunity of fish and improve the disease resistance of fish in fish farming, which also helps to reduce farming risks. In fish farming, lysine has an obvious effect on improving fish food intake, mainly because lysine has a significant effect on improving the function of fish intestinal digestive enzymes, and digestive enzymes have unique functions in the digestion process. Substances, the digestive power of animals is closely related to the activity of digestive enzymes in the digestive tract. In addition, in pig breeding, lysine can also use its own substances to methylate toxic substances or drugs to detoxify.
The addition of lysine in pig feed is different due to the different types of pigs, and the addition ratio is also different. The specific addition ratio is as follows:
(1) Weaned piglets
The recommended values of lysine requirement for piglets are 1.35% (5-10kg) and 1.15% (10-20kg), which account for 5.7% and 5.5% of total dietary protein, respectively.
(2) Lean pork
Feeding standards recommend that piglets require 1.0% (5-10kg) and 0.75% (10-20kg) of lysine, accounting for 4.5% and 4.1% of total dietary protein, respectively. Studies have shown that 8-20kg piglets require 0.84%-1.2% of lysine, and the ratio of lysine to protein is 5.2%-6.0%.
(3) Growing and finishing pigs
The recommended values for lysine requirements for growing-finishing pigs are similar in other countries, with the exception of the higher standard in the United Kingdom, which is approximately 0.7% in the growing period and 0.6% in the finishing period. The researchers studied the effect of supplementing lysine and tryptophan in the diet of growing pigs (20-35kg), and the results were 0.6% lysine and 0.15% tryptophan.
The NRC stipulates that the dietary lysine level of pregnant sows is 0.44%-0.50%, that of lactating sows is 0.71%-0.90%, and that of breeding pigs is 0.60%.