Effect of Fibrous By-Products on Production and Ruminal Fermentation in Lactating Dairy Cows

¹ Department of Animal Science, University of Missouri, Columbia 65211
² Department of Math Sciences, University of Missouri, Columbia 65211

Lactating dairy cows were used in experiments to determine the effects of feeding a combination of fibrous by-products to replace a portion of alfalfa hay or grain. Cows were fed a control diet, consisting of alfalfa hay, corn, soybean meal, and corn silage or one of four treatment diets. In these diets, a combination of soy hulls, corn gluten feed, and wheat midds replaced approximately 30 or 60% of alfalfa hay or 25 or 50% of corn and soybean meal. A 56-d production study used 50 mid-lactation dairy cows in a randomized complete block design. No differences in milk production or composition among treatments were measured, except for the diet in which 60% of the alfalfa hay was replaced with fibrous by-products. Cows fed this diet had a significantly lower percentage of milk fat compared with other treatments. A fermentation study used five fistulated, multiparous lactating dairy cows in a 5 x 5 Latin square design. Cows were fed one of the five experimental diets used in the production study during five consecutive 14-d periods. Rumen acetate to propionate ratio was highest for the control and 50% concentrate replacement diets (3.27) and lowest for the 60% hay replacement diet (2.78). This shift in ruminal volatile fatty acid profile corresponded to the change in milk fat percentage, measured during the production study. A mixture of fibrous by-products fed as an alternative to hay or grain ingredients could potentially decrease feed costs without a resultant decrease in milk production by mid-lactation dairy cows.

Key Words: fibrous by-products • lactating dairy cows • fat-corrected milk • rumen fermentation

Submitted on December 28, 1998
Accepted on July 12, 1999

This article has been cited by other articles:

				N. B. Kristensen, J. Sehested, S. K. Jensen, and M. Vestergaard Effect of Milk Allowance on Concentrate Intake, Ruminal Environment, and Ruminal Development in Milk-Fed Holstein Calves J Dairy Sci, September 1, 2007; 90(9): 4346 - 4355. [Abstract] [Full Text] [PDF]

				I. Halachmi, E. Maltz, N. Livshin, A. Antler, D. Ben-Ghedalia, and J. Miron Effects of Replacing Roughage with Soy Hulls on Feeding Behavior and Milk Production of Dairy Cows Under Hot Weather Conditions J Dairy Sci, July 1, 2004; 87(7): 2230 - 2238. [Abstract] [Full Text] [PDF]