Effects of diets on the rumen and blood volatile fatty acid concentration of growing calves

Abstract

Twenty-four calves belonging to the White Fulani (WF), Friesian and German Brown (GB) breed were used to evaluate the effects of milk-based diets, on rumen fermentation pattern and blood volatile fatty acid concentrates. The calves were assigned randomly to four diets as they become available at the age of 4 days, and fed their respective diets for 84 days. The diets were:

1. milk fed twice daily plus a concentrate and grass supplement (TMCG)
2. milk fed twice daily plus a concentrate supplement (TMC)
3. milk fed twice daily plus a concentrate and grass supplement (OMCG)
4. milk fed twice daily plus a concentrate supplement (OMC)

Rumen and blood samples were taken on the last 3 days of the 14^th, 8^th, and 12^th week of the experiment for the measurement of rumen pH, rumen and blood volatile fatty acid (VFA) concentrate.

Significant age, breed and dietary effects were observed on rumen and plasma volatile fatty acid concentrates but not on rumen Ph. Friesian and GB calves had higher total rumen VFA than WF calves (3.3, 3.1 and 2.4 meg/100ml respectively) and plasma VFA concentration followed a similar pattern. Both the plasma and rumen total VFA increased (p <.01) with age, and grass supplemented calves tended to have higher VFA concentrations. Significant positive correlation were observed between rumen and plasma VFA concentration, while significant negative correlation were observed between rumen pH and VFA concentration.