Variation in Nutrient Composition of Feeds on US Dairy Farms
Estimates of the amount of variation (i.e.,standard deviations and ranges) in nutrient composition of common feeds are readily available from some national feed testing labs,however,estimates of variation for feeds within a farm are needed to determine appropriate feed sampling and ration re-formulation schedules.We conducted a large national survey to determine within farm variation for some common feeds.On average within farm variation for crude protein (CP) and neutral detergent fiber (NDF) was 2 or 3 times less than variation in the national population.Within a farm,substantial day to day variation in dry matter,NDF,CP and starch was observed for corn silage and haycrop silage indicating that samples should be taken over several days and those results averaged for diet formulation purposes.In some cases,day to day variation was as great as month to month variation.The concentrations of NDF,but not CP,in high moisture corn,distillers grain,and brewers grains varied almost as much as NDF concentrations in some forages indicating that these feeds should be sampled on a regular basis.
Bill Weiss Dianne Shoemaker Lucien McBeth Peter Yoder Normand St-Pierre
Department of Animal Sciences The Ohio State University, Wooster 44691
国际会议
3rd International Symposium on Dairy Cow Nutrition and Milk Quality(第三届“奶牛营养与牛奶质量国际研讨会)
北京
英文
122-130
2013-05-11（万方平台首次上网日期，不代表论文的发表时间）