Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Animal, Dairy, and Veterinary Sciences

Committee Chair(s)

Ronald L. Boman


Ronald L. Boman


William F. Campbell


Michael J. Arambel


Twenty-four early to midlactation Holstein cows were allocated to one of three treatments. Treatments consisted of: 1) basal ration plus 60 g wheat bran per day per head (control); 2) basal ration plus 57 g yeast culture per day per head; 3) basal ration plus 57 g yeast culture plus 3 g Aspergillus oryzae per day per head. Feed intake and milk yield were recoreded daily and milk composition and body weights were recorded weekly. Feed and fecal samples were recorded weekly. Feed and fecal samples were collected to determine apparent nutrient digestibility. No statistical difference was observed in milk yield among treatments. Percent fat, protein, and solid non fat of milk samples for the control fed group was significantly higher than the other treatment groups. Apparent crude protein, acid detergent fiber, and neutral detergent fiber digestibilities for cows fed the fungal culture treatments were significantly higher.

Six rumen-fistulated Holstein cows were randomly assigned to one of three treatments in a 3 x 3 replicated Latin square design. Rumen pH was significantly lower for cows fed treatment two. Total volatile fatty acid and ammonia nitrogen concentration were higher for cows fed treatment two.

Three rumen-fistulated Holstein cows were assigned one of three treatments in a 3 x 3 Latin square design for an in situ study. Approximately 15 g of grass hay, low quality alfalfa, and high quality alfalfa were sealed in nylon bags and put into the rumen. Samples were analyzed for dry matter, acid detergent fiber, neutral detergent fiber, and crude protein. Regardless of substrate used, dry matter disappearance was lower for control. Regardless of treatment ration fed, high quality alfalfa as a substrate was significantly higher in dry matter disappearance.