Abstract:

【Objective】 The distribution of calcium contents in feed resources for livestock and poultry feed in China was investigated to provide scientific basis for rational use of feed resources and precise formulation of livestock and poultry’s diets.【Method】 Thirty-seven kinds of feedstuffs, a total of 3 862 samples, were collected from 31 provinces (cities, regions) of China according to a unified data collection specification, and the samples were digested by microwave to determine Ca contents by inductively IRIS IntrepidⅡ coupled plasma emission spectrometer.【Result】 Average Ca contents in feedstuffs were as follows: cereal seeds, 457 mg·kg ^-1 (74.5-832 mg·kg ^-1), the highest and lowest Ca contents were observed in the barley and corn, respectively, and coefficients of variation ranged from 21.2% to 85.3%; cereal by-products, 1 090 mg·kg ^-1 (93.4-3 264 mg·kg ^-1), the highest and lowest Ca contents were observed in the wheat DDGS and broke rice, respectively, and coefficients of variation ranged from 19.5% to 142%; plant-protein feeds, 3 987 mg·kg ^-1 (1 742-7 909 mg·kg ^-1), the highest and lowest Ca contents were observed in the rapeseed meal and peanut meal, respectively, and coefficients of variation ranged from 0.92%-34.6%; animal-protein feeds, 14 448 mg·kg ^-1 (115-50 007 mg·kg ^-1), the highest and lowest Ca contents were observed in the fish meal and dried blood cells, respectively, and coefficients of variation ranged from 25.0%-239%; straw feeds, 5 969 mg·kg ^-1 (1 931-13 524 mg·kg ^-1), the highest and lowest Ca contents were observed in the sweet potato vines and wheat straw, respectively, and coefficients of variation ranged from 27.6% to 39.0%; forge feeds, 6 667 mg·kg ^-1 (4 157-13 963 mg·kg ^-1), the highest and lowest Ca contents were observed in the alfalfa and leynus chinensis, respectively, and coefficients of variation ranged from 30.3% to 94.6%; mineral feeds, 30% (19.2%-41.2%), the highest and lowest Ca contents were observed in the shell meal and bone meal, respectively, and coefficients of variation ranged from 2.67% to 24.0%. The distribution regularities of Ca contents in feedstuffs were as follows: mineral feeds＞animal-protein feeds＞forage feeds＞straw feeds＞plant-protein feeds＞cereal by-products＞cereal seeds. A significant difference (P＜0.05) was also observed in Ca contents among different feeds in the same category. Regional comparisons on a basis of provinces (regions) were made among Ca contents of corn, wheat and soybean meal, and showed that the Ca contents in corn and soybean meal but not wheat (P＞0.05) were greatly affected (P＜0.05) by environmental changes in different regions. The average Ca contents of corn in provinces (regions) ranged from 48.1 to 155 mg·kg ^-1, the highest and lowest Ca contents of corn were observed in Shanxi and Liaoning, respectively, and coefficients of variation ranged from 20.1% to 321%; the average Ca contents of wheat of provinces (regions) ranged from 362 to 590 mg·kg ^-1, the highest and lowest Ca contents of wheat were observed in the Shanxi and Hubei, respectively, and coefficients of variation ranged from 8.29% to 66.1%; the average Ca contents of soybean meal of provinces (regions) ranged from 3 001 to 4 153 mg·kg ^-1, the highest and lowest Ca contents of wheat were observed in the Shanxi and Jiangsu, respectively, and coefficients of variation ranged from 1.30%-21.4%.【Conclusion】 The Ca contents in feedstuffs of our country were greatly influenced by types and regions. The results from the current study would be of great significances toward having knowledge of actual Ca contents in the feedstuffs to precisely formulate diets in order to ensure animal health and efficient production.

Key words: livestock and poultry, feed resources, calcium contents, diets