关键词: 饲料原料, 硒含量, 猪, 鸡

Abstract:

【Objective】 The purpose of this survey was to study the distribution of selenium (Se) contents in various feed ingredients from different regions and the basal diets of pigs and chickens of China, so as to provide a basis for the reasonable addition of Se to the diets.【Method】 A total of 3 785 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 provinces, municipalities and autonomous regions. After pretreatment, microwave digestion was performed with MARS6 high-throughput closed microwave digestion system, and then feed samples were determined by ion chromatography-inductively coupled plasma-mass spectrometer (IC-ICP-MS). The pig liver powder was used as a reference material to ensure the reliability of the measurement results.【Result】 The determination of Se contents in feedstuffs showed that the average Se content of cereal feeds (including corn, wheat, rice and barley) was 0.037 mg·kg ^-1 (ranged from 0.025 to 0.044 mg·kg ^-1); cereal by-products (including corn gluten meal, corn DDGS, corn germ meal, wheat middling, wheat bran, wheat DDGS, broken rice and rice bran) was 0.071 mg·kg ^-1 (ranged from 0.034 to 0.124 mg·kg ^-1); plant protein feeds (including extruded soybean, soybean meal, rapeseed meal, cottonseed meal, peanut meal, linseed meal and sunflower meal) was 0.209 mg·kg ^-1 (ranged from 0.097 to 0.502 mg·kg ^-1); animal protein feeds (including fish meal, meat meal, hydrolyzed feather meal, dried porcine soluble, plasma protein powder and blood cells protein powder) was 1.217 mg·kg ^-1 (ranged from 0.611 to 2.220 mg·kg ^-1); pasture feeds (including Leymus chinensis, ryegrass, alfalfa and corn silage) was 0.062 mg·kg ^-1 (ranged from 0.057 to 0.070 mg·kg ^-1); straw feeds (including corn straw, wheat straw, rice straw and sweet potato vine) was 0.069 mg·kg ^-1 (ranged from 0.033 to 0.128 mg·kg ^-1); mineral feeds (including limestone, dicalcium phosphate, bone meal and oyster shell meal) was 0.352 mg·kg ^-1 (ranged from 0.085 to 0.544 mg·kg ^-1). Results showed that the average Se contents of these 37 kinds of feeds ranged from 0.025 to 2.220 mg·kg ^-1 and the Se contents distribution of different species feeds were as follows: animal protein feeds (1.217 mg·kg ^-1)＞ mineral feeds (0.352 mg·kg ^-1) ＞ plant protein feeds (0.209 mg·kg ^-1) ＞cereal by-products (0.071 mg·kg ^-1) ＞straw feeds (0.069 mg·kg ^-1) ＞ pasture feeds (0.062 mg·kg ^-1) ＞cereal feeds (0.037 mg·kg ^-1).The Se contents in corn, wheat or soybean meal from some provinces (regions) were significantly different (P＜0.05). The Se contents of corn samples from all the provinces (regions) were deficient (≤0.05 mg·kg ^-1), and 61.1% provinces (regions) were severely deficient (≤0.02 mg·kg ^-1). The Se contents of wheat samples from Sichuan province were serious deficient (≤0.02 mg·kg ^-1). The Se contents of soybean meal samples from Sichuan province and Inner Mongolia were deficient (0.03-0.05 mg·kg ^-1), and that from Henan province were critical deficient (0.06-0.09 mg·kg ^-1). Calculated Se contents from 153 feed formulas commonly used in pigs and chickens all over the country ranged from 0.06 to 0.11 mg·kg ^-1, which could provide about a quarter of the Se requirement for pigs and chickens according to feeding standards of China. 【Conclusion】 The Se contents enrichments of feeds in livestock and poultry are different among different types and regions in China. The Se contents in the basal diet formula could provide about a quarter of the Se requirement for pigs and chickens in China. Therefore, it is suggested that we should formulate the diet accurately according to distribution data of Se contents in feedstuffs from different types and different areas, so as to meet the need of efficient production of livestock and poultry and reduce supplemental Se level.

Key words: feedstuff, selenium content, pig, chicken