奶牛正常乳与隐性乳房炎乳中脂肪酸组成的比较研究

Comparative Study on Fatty Acid Composition between Normal Milk and Subclinical Mastitis Milk of Dairy Cow

旨在研究奶牛隐性乳房炎导致产奶量下降和乳成分的变化。使用气相色谱仪测定57头荷斯坦奶牛(其中32头患隐性乳房炎)乳中脂肪酸组分,比较正常乳和隐性乳房炎乳中脂肪酸的组分。结果表明:共检出21种脂肪酸,隐性乳房炎乳中棕榈油酸(C16∶1)的含量高于正常乳,其他20种脂肪酸均低于正常乳,其中有9种显著低于正常乳(P<0.05),2种极显著低于正常乳(P<0.01);隐性乳房炎降低了牛奶中脂肪酸的总含量及饱和脂肪酸、单不饱和脂肪酸和多不饱和脂肪酸的含量;隐性乳房炎乳中饱和脂肪酸和单不饱和脂肪酸的百分比高于正常乳,多不饱和脂肪酸的百分比则低于正常乳。结果提示,隐性乳房炎影响奶牛脂肪酸合成过程,改变了脂肪酸的组分。

The aim of the study was to investigate that subclinical mastitis of dairy cow causes the decline of milk yield and the change of milk composition.Detect milk fatty acids of 57 Holstein cows（32 of them suffer from subclinical mastitis）with gas chromatography,and compare fatty acid composition of normal milk with subclinical mastitis milk.The results showed that 21 fatty acids which were from C4 to C22 could be found out,the content of palmitoleic（C16∶1） in subclinical mastitis milk was higher than that in normal milk,but other 20 kinds of fatty acids were lower,9 fatty acids in subclinical mastitis milk were significantly lower than that in nomal milk（P0.05）,and 2 fatty acids in subclinical mastitis milk were great significantly lower than that in nomal milk（P0.01）.Subclinical mastitis reduced the total content of milk fatty acids and the content of saturated fatty acid,monounsaturated fatty acid and polyunsaturated fatty acid.Saturated fatty acid percentage and monounsaturated fatty acid percentage of subclinical mastitis milk were higher than that in normal milk,but polyunsaturated fatty acid percentage of subclinical mastitis milk was lower than that in normal milk.Consequently,subclinical mastitis affects the synthetic process of cow fatty acids and changes the composition of fatty acids.