Effect of dietary roughage level on chewing activity, ruminal pH, and saliva secretion in lactating Holstein cows

摘要：

Introduction Subacute ruminal acidosis (SARA) is a prevalent metabolic disorder in early and mid-lactation dairy cows (Enemark, 2008) and can cause production and health problems.Increasing dietary roughage level is a commonly used strategy to prevent SARA in high producing dairy cows.It is hypothesized that high roughage level diets promote chewing activity, which promotes saliva secretion and helps to maintain a healthy rumen function (Mertens, 1997).Thus, chewing activity has been used as an indicator of rumen health for several years (Maekawa et al., 2002).Previousstudies consistently showed that the increased roughage level increased chewing activity and elevated ruminal pH.However, these studies did not determine the relationship between chewing activity and saliva secretion.High roughage diet reduces degradable dietary OM in the rumen and hence decreases the rate of VFA production.Therefore, the elevated ruminal pH may be due to the depressed VFA production rather than an increase in saliva secretion.

作者: F.G Jiang X.Y.Lin Z.G.Yan Z.Y.Hu G.M.Liu Z.H.Wang

作者单位: Ruminant Nutrition and Physiology Laboratory, College of Animal Science and Technology, Shandong Agricultural University, Taian 271018, P.R.China

会议类型: 国际会议

会议名称: The 5h International Symposium on Dairy Cow Nutrition and Milk Quality(第五届“奶牛营养与牛奶质量国际研讨会)

会议地点: 北京

会议语种:英文

页码: 189-191

在线出版日期: 2017-05-05（万方平台首次上网日期，不代表论文的发表时间）