Detailed Study on New Technologies for Pig and Chicken Nutritional Parameters and Formulations

Solving the global shortage of protein feed and the environmental pollution caused by nitrogen in livestock and poultry excreta has become one of the main themes of animal nutrition research in various countries, and is also one of the research contents of this project. The technical key lies in how to scientifically evaluate feed protein quality, formulate carbon-nitrogen and amino acid balanced diets, and improve the utilization rate of feed protein. The main contents of this study are as follows:

(1) Using internationally recognized advanced experimental methods (ileo-rectal anastomosis pigs and caecectomized chickens), the digestible amino acid and other effective component contents of 40 commonly used feedstuffs for pigs and chickens in China were systematically determined, and a Chinese feed composition table based on digestible amino acids was completed. The evaluation of feed protein quality was advanced from crude protein, digestible crude protein and amino acid content to the stage of digestible amino acid content, enriching the basic theories of nutrition.

The total phosphorus and non-phytate phosphorus contents of 40 feedstuffs were determined. Replacing the concept of available phosphorus with feed non-phytate phosphorus content more accurately expresses the form of existence and utilization of feed phosphorus, which is of particular importance for the rational utilization of feed phosphorus and mineral phosphorus.

(2) Using the "dose-response method", the digestible amino acid requirements and the requirements, tolerance levels and interactions of vitamins A, D and E for broilers of different sexes were systematically studied. Combined with China's production reality, 66 nutrient requirement parameters for broilers were proposed, and a supply table of major nutrients for broilers was completed.

(3) According to seasonal changes, the nutritional requirements including digestible amino acids for laying hens and meat-type breeding chickens were studied, and 28 nutritional requirement parameters for laying hens and 36 nutritional requirement parameters for meat-type breeding chickens were proposed.

(4) Using internationally advanced technologies and methods, the nutrient requirements of growing-finishing pigs were studied, and 33 nutritional parameters suitable for China's national conditions were proposed. This filled the research gap in this field in China.

(5) A feed formulation knowledge base was established based on the pig and chicken feed knowledge base, nutrition knowledge base and expert system for pig and chicken feed formulation design.

According to this composition table and the recommended nutrient levels for pigs and chickens, the average body weight of 7-week-old broilers reached 2.30 kg, with a feed conversion ratio of 1.9-2.0:1; the average egg production per laying hen over the whole period reached 17.5 kg, with a feed conversion ratio of 2.60:1; the average daily gain of growing-finishing pigs reached 900 g, with a feed conversion ratio of 2.50:1. The results of this project have a broad guiding role for the feed industry and the pig and chicken farming industries, with strong practicality. Over 4 years, 2.965 million tons of pig and chicken compound feed, 5,088 tons of 1% premix, 144,400 tons of concentrated feed, and 1,880 tons of additives were promoted, achieving direct economic benefits of 344 million yuan.