Rumen Acidosis and its Effects on Milk Production
Subacute ruminal acidosis (SARA) occurs when rumen pH is depressed for several hours per day due to accumulation of volatile fatty acids and insufficient rumen buffering. No agreement exists on the severity and duration of the pH depression of SARA. Rumen pH thresholds ranging from 5.5 to 6.0 have been used for the diagnosis of this disease. Surveys in the USA suggested an incidence of SARA of between 19 and 26％ in early and mid-lactation dairy cows. The present review describes causes for SARA, including feeding excessive amounts of non-structural carbohydrates, feeding highly fermentable forages, and insufficient dietary coarse fibre. This paper reviews the effects of SARA on the depression of feed intake and milk fat. Other effect of SARA that are not reviewed in this paper include diarrhea, laminitis, liver abscesses, inflammation, lysis of and production of endotoxins by gram negative bacteria in the rumen and in the large intestine, and major changes in the population of rumen microbes.
J.C.Plaizier E.Khafipour S.Li D.O.Krause
Department of Animal Science, University of Manitoba, Winnipeg, Manitoba, Canada Department of Animal Science, University of Manitoba, Winnipeg, Manitoba, Canadar
国际会议
奶牛营养与牛奶质量国际研讨会(ist International Symposium on Dairy Cow Nutrition and Milk Quality)
北京
英文
64-70
2009-05-04（万方平台首次上网日期，不代表论文的发表时间）