Effect of neutral detergent fiber and tallow supplementation in total mixed ration using coarse ground rice straw as main fiber source in dairy cows

Abstract

The objective of the study was to investigate the effects of dietary neutral detergent fiber (25 or35%DM) and tallow supplementation (0 or 5%DM) in total mixed ration using coarse ground rice straw as the mainfiber source in ruminally fistulated and milking cows. The experiment was split into 2 parts. In the first experiment,four ruminally fistulated Holstein Friesian non-lactating dairy cows were assigned in a 4x4 Latin square design.The result indicated that increasing dietary neutral detergent fiber and tallow supplementation affected dry matter and nutrient intake (P<0.05) but did not affect on ruminal pH, ruminal ammonia-nitrogen, bacteria and protozoapopulation, and blood metabolites (P>0.05). In the second experiment, sixteen crossbred and purebred HolsteinFriesian lactating dairy cows, average weight 450 kg in second to third of lactation and midlactation, were assignedin 2x2 factorial arrangement in a randomized complete block design. The result indicated that increasing dietary neutraldetergent fiber and tallow supplementation had no effect on dry matter intake, milk yield, and milk composition(P>0.05) except solids-not-fat tended to be decreased with tallow supplementation in total mixed ration (P<0.05).