267 - Effect of Hay Type on the Winter Growth of Bos Grunniens Raised in Eastern Kentucky

Bos grunniens (yak) have been utilized as a source of fiber, milk, dung, meat and transportation in the high-altitude regions of Asia for centuries. Limited research has been conducted on the species in North America. The objective of this on-farm research was to evaluate the effect of hay type on growth rate of growing yaks. Forages evaluated included alfalfa (A), orchardgrass-red clover (O) and a cool-season pasture grass species mixture (P). The experimental design was a partially balanced 3x3 Latin square with an extra pen. Yaks were stratified to pens by age and sex resulting in a pen of mixed sex (3 males/2 females) recently weaned calves, a pen of five yearling females, and two pens of five yearling males. Each period lasted for 45 days and animal weights were collected at the beginning and end to assess weight change and daily gain. Hay offered was weighed and feeding losses were visually estimated to determine hay DM disappearance. Forage samples were collected and analyzed for nutrient content. Data were analyzed using the PROC GLM procedure of SAS. No carryover effects were noted and means were separated using Tukey’s multiple comparison test where α=0.10. Forage type had a significant impact on period weight change of growing yaks during the winter with O having greater weight gain (9.5 kg) than P (-4.7 kg) with A being intermediate (8.5 kg). Forage DM disappearance when expressed as percent of body weight was greater for A (2.70) compared to P (2.25) while O (2.28) was not different from either. Forage type and quality can impact weight gain and forage disappearance during the winter months for growing yaks with higher quality forage providing greater weight gain.