Lactational Responses to Ruminally Undegradable Protein by Dairy Cows Fed Diets Based on Alfalfa Silage

Synthesis of microbial protein in ruminally cannulated cows fed alfalfa silage, alfalfa hay, or corn silage.

Six ruminally cannulated cows were used in an experiment with a 3 x 3 Latin square design. Three all forage diets-alfalfa silage, alfalfa hay, or corn silage plus 2.2% urea (DM basis)-were fed for ad libitum intake four times daily. The microbial protein marker 15NH3 and the liquid marker Cr-EDTA were infused continuously into the rumen for 72 and 48 h, respectively; the solid marker, Yb-labele...

Effect of yeast culture supplementation of alfalfa silage or alfalfa hay fed to lactating dairy cows

Efficacy of carbohydrate sources for milk production by cows fed diets based on alfalfa silage.

The effectiveness of three carbohydrate sources, high-moisture ear corn (HMEC), cracked shelled corn (CSC), and a 50:50 mixture of HMEC plus dried citrus pulp (DCP), fed with or without supplemental rumen-undegraded protein as expeller soybean meal (ESBM), was assessed in 48 multiparous dairy cows. All diets contained (dry mater [DM] basis) 50% alfalfa silage, 10% ryegrass silage, 28% NDF, and ...

Amino Acid Supply and Metabolism in Relation to Lactational Performance of Dairy Cows Fed Grass Silage Based Diets

The main objective of the thesis was to study AA supply of dairy cows fed grass silage based diets with specific emphasis on the impact of changing individual and total AA supplies arising from individual AA supplementations or changes in the diet on milk production and AA utilisation. Mammary AA metabolism was also studied to broaden the understanding of the mechanisms underlying altered lacta...

Lactational responses to postruminal infusions of amino acids in dairy cows fed maize silage, hay or grass silage.

Duodenal infusions of methionine and ly-sine have been shown to increase milk protein yield in dairy cows given a dehydrated maize diet (Rulquin, 1987). As du-odenal amino acids (AA) profiles vary according to diet (Le Henaff, unpublished), a trial was undertaken to test the lactational responses of dairy cows to methionine and lysine infusions with 3 other diets based on either maize silage (M...