异位酸影响反刍动物瘤胃代谢和生产性能的研究进展

Effects of Isoacids on Ruminal Metabolism and Performance in Rumiants:A Review

异位酸主要指异丁酸、异戊酸、2-甲基丁酸和戊酸,属于短链挥发性脂肪酸。异位酸对于反刍动物瘤胃内的纤维降解菌具有促进作用,能够提高饲料纤维的降解消化率;异位酸还可以促进瘤胃内支链氨基酸的生物合成,进而提高微生物蛋白的合成;而且异位酸能够抑制脲酶,增加瘤胃内非蛋白氮的利用和机体内氮的留存,提高动物的增重性能;此外,异位酸还可以促进瘤胃内乙酸的生成,进而提高反刍动物的产奶量及乳脂率。本文旨在阐述异位酸对反刍动物瘤胃消化代谢及其对产奶量、动物增重等生产性能的影响,以期为异位酸在反刍动物生产实践中的合理利用提供科学理论依据。

Isoacids are the branched ketoacids resulting from the natural rumen fermentation of their corresponding amino acids.Isobutyric,isovaleric,2-methylbutyric and valerate are produced in the rumen mainly by oxidative deamination and decarboxylation of the amino acids valine,leucine,isoleucine and proline,respectively.Isoacids are essential nutrients and enhance the growth of fiber-digesting microorganisms in the rumen,which results in more efficient feed utilization of fiber.More microbial protein will be produced when isoacids were added in the diets.Besides,the supplementation of isoacids can potentially increase the utilization of nonprotein nitrogen by inhibiting the activity of urease.The increase of nitrogen retention will ultimately promote body weight gain in ruminants.In addition,isoacids have a favorable response on rumen acetate production,which making more energy available for increased milk production and milk fat rate.The objective of the present paper was to elucidate the effects of isoacids on ruminal metabolism,milk yield,weight gain and other performance in ruminants to provide a scientific reference in further practical usage of isoacids.