How dairy cow-calf performance is impacted by rumen-protected methionine supplementation during transition and heat stress

Researchers at the University of Wisconsin – Madison examined the effects on cow-calf performance when heat-stressed transition cows received supplemental RPM.  Fifty-three cows were fed either a control diet or a control diet with Smartamine M beginning six weeks before expected calving. Four weeks pre-calving all methionine cows and half the control cows received an electric heat blanket. The other half of the control cows were left at thermoneutrality. Overall, RPM supplementation to transition cows reverts the negative impact of heat stress on milk protein and calf wither heights.   

The research results underscore the negative effects of heat stress on milk protein production and birth weight of calves. Consistent with previous work using late-lactation cows, methionine supplementation helped to mitigate the negative effects of heat stress on milk protein. Supplemental methionine during the transition period has been increasing on commercial farms due to the beneficial effect of methionine on milk production, health and metabolism as well as on the developing fetus.  

Features: Brittney Davidson, Ph.D. student at the University of Wisconsin-Madison, USA.