UVM Theses and Dissertations
Format:
Print
Author:
Myers, E. R.
Dept./Program:
Animal Sciences
Year:
2009
Degree:
MS
Abstract:
The rising cost of corn grain has resulted in a push to minimize corn grain and starch concentration in diets for dairy cows. Feeding byproducts like distillers grains, wheat middlings and beet pulp can decrease the cost of feed on the dairy by serving as a replacement for corn grain. In addition, forages can be difficult to grow in some parts of the world (e.g Japan) and unlike western dairy rations, this class of feeds may be one of the most expensive components of the ration. Byproduct feeds; however, are becoming more readily available, resulting in a system in which feeding large amounts of byproducts, but low-starch and low-forage would be an attractive and low cost option if productivity, efficiency and health could be maintained in the dairy cow.
Diets that are low in both starch and forage content present several potential nutritional issues for high producing dairy cows. Diets must contain sufficient rumen fermentable carbohydrates and physically effective fiber (peNDF) to maintain milk production and rumen health. Saliva production and rumination stimulated by peNDF are critical to rumen buffering capacity and maintenance of the rumen mat. Previous research (Dann et al., 2008), has indicated that low-starch diets (below 20% starch) can be fed without significantly affecting milk production. However, the minimum forage level that can be fed in combination with a low-starch concentration without decreasing animal performance, has yet to be determined. We hypothesize that low-starch, low-forage diets can be fed to high producing dairy cows without decreasing performance or rumen fermentation.
Sixteen lactating Holstein cows (8 rumen fistulated) were used in a replicated 4x4 Latin square design with 21-d periods (9-d collection) to determine the effect of feeding diets containing low-starch (21% DM) and different amounts of forage (52,47,43, and 39% of DM) on lactational performance and rumen characteristics. The primary diet ingredients that were altered between the diets (52% forage to 39% forage) on a DM basis, were corn silage (37 to 28%), haylage (14 to
Diets that are low in both starch and forage content present several potential nutritional issues for high producing dairy cows. Diets must contain sufficient rumen fermentable carbohydrates and physically effective fiber (peNDF) to maintain milk production and rumen health. Saliva production and rumination stimulated by peNDF are critical to rumen buffering capacity and maintenance of the rumen mat. Previous research (Dann et al., 2008), has indicated that low-starch diets (below 20% starch) can be fed without significantly affecting milk production. However, the minimum forage level that can be fed in combination with a low-starch concentration without decreasing animal performance, has yet to be determined. We hypothesize that low-starch, low-forage diets can be fed to high producing dairy cows without decreasing performance or rumen fermentation.
Sixteen lactating Holstein cows (8 rumen fistulated) were used in a replicated 4x4 Latin square design with 21-d periods (9-d collection) to determine the effect of feeding diets containing low-starch (21% DM) and different amounts of forage (52,47,43, and 39% of DM) on lactational performance and rumen characteristics. The primary diet ingredients that were altered between the diets (52% forage to 39% forage) on a DM basis, were corn silage (37 to 28%), haylage (14 to