关键词: 饲料原料, 铜含量, 猪, 鸡

Abstract:

【Objective】 The purpose of this survey was to study the distribution of copper (Cu) contents in various feed ingredients from different regions, as well as the Cu content in the basal diets of livestock and poultry in China, so as to provide a basis for the reasonable addition of Cu to diets. 【Method】 A total of 3 903 feed samples from 37 feed ingredients which fallen into seven types (cereal feeds, cereal by-products, plant protein feeds, animal protein feeds, pasture feeds, straw feeds and mineral feeds) from 31 regions (provinces, municipalities and autonomous regions). After pretreatment of those samples, microwave digestion was performed with MARS6 high-throughput closed microwave digestion system, and then the Cu contents of feed samples were determined by IRIS Intrepid Ⅱ. The pig liver or soybean powder were used as a reference material to ensure the reliability of the measurement results. 【Result】 The determination of Cu contents in feedstuffs showed that the average Cu content of cereal feeds (including corn, wheat, rice and barley) was 3.95 mg·kg ^-1 (ranged from 2.50 to 5.34 mg·kg ^-1); the average Cu content of cereal by-products (including corn gluten meal, corn DDGS, corn germ meal, wheat middling, wheat bran, wheat DDGS, broken rice and rice bran) was 7.16 mg·kg ^-1 (ranged from 1.62 to 12.13 mg·kg ^-1); the average Cu content of plant protein feeds (including extruded soybean, soybean meal, rapeseed meal, cottonseed meal, peanut meal, linseed meal and sunflower meal) was 16.37 mg·kg ^-1 (ranged from 6.45 to 30.40 mg·kg ^-1); the average Cu content of animal protein feeds (including fish meal, meat meal, hydrolyzed feather meal, dried porcine soluble, plasma protein powder and blood cells protein powder) was 11.14 mg·kg ^-1 (ranged from 1.90 to 20.04 mg·kg ^-1); the average Cu content of pasture feeds (including Leymus chinensis, ryegrass, alfalfa and corn silage) was 7.85 mg·kg ^-1 (ranged from 4.31 to 9.92 mg·kg ^-1; the average Cu content of straw feeds (including corn straw, wheat straw, rice straw and sweet potato vine) was 7.50 mg·kg ^-1 (ranged from 3.38 to 13.89 mg·kg ^-1); the average Cu content of mineral feeds (including limestone, dicalcium phosphate, bone meal and oyster shell meal) was 6.79 mg·kg ^-1 (ranged from 3.39 to 11.45 mg·kg ^-1). Results showed that the average Cu contents of these 37 kinds of feeds ranged from 1.62 to 30.40 mg·kg ^-1 and the Cu contents distribution of different species feeds were as follows: plant protein feeds (16.37 mg·kg ^-1)＞animal protein feeds (11.14 mg·kg ^-1)＞pasture feeds (7.85 mg·kg ^-1)＞straw feeds (7.50 mg·kg ^-1)＞cereal by-products (7.16 mg·kg ^-1)＞mineral feeds (6.79 mg·kg ^-1)＞cereal feeds (3.95 mg·kg ^-1). It was found that the Cu contents in corn, wheat or soybean meal from some provinces (regions) were significantly different (P＜0.05). The highest and lowest Cu contents of corn and soybean meal were observed in Sichuan (2.97 and 15.74 mg·kg ^-1) and Inner Mongolia (1.66 and 11.72 mg·kg ^-1), respectively; the highest and lowest Cu contents of wheat were observed in Gansu (5.61 mg·kg ^-1) and Hebei (4.02 mg·kg ^-1) provinces, respectively. Calculated Cu contents from 152 feed formulas commonly used in pigs and chickens all over the country ranged from 5.07 to 6.54 mg·kg ^-1. According to Cu requirements of pigs and chickens from feeding standards of China and NRC of the United States, the Cu contents in the basal diets could provide the Cu nutrition requirements of pigs basically and provide most of the Cu nutrition requirements of chickens. However, the utilization rate of Cu in different feed ingredients had not been considered. 【Conclusion】 The above results showed that the Cu contents in feed ingredients varied greatly in different kinds and regions, and the Cu contents in the basal diets from common formulations of pigs and chickens in our country could provide most of the nutritional requirements for pigs and chickens. Therefore, it was suggested that the Cu contents and its utilization rate of the basal diets from different regions should be considered to formulate the diets accurately, so as to meet the need of efficient production of livestock and poultry and reduce the environmental pollution caused by Cu addition and emission.

Key words: feedstuff, copper content, pig, chicken