Relationship between Plasma Amino Acid Profile and Ovarian Function around the Time of Ovulation in Beef Cows
Pairing low quality forage with coproducts from the ethanol industry, likely results in excess dietary crude protein (CP) consumption. The effects of these excessive CP diets on beef cow reproduction have been shown to enhance ovarian parameters. However, the effects of excess dietary CP on circulating plasma amino acid (AA) profile are dependent on source and amount being supplemented. In the present study, we observed if relationships between blood plasma AA and ovarian parameters of beef cows consuming excess dietary CP (25 - 50%) around the time of ovulation existed. We observed that total plasma AA and essential AA were positively correlated with length of proestrus. In addition, as a percent of total plasma AA, progesterone concentrations 7 d post estrus were positively correlated with total essential AA. Based on these data, blood plasma AA appear to be correlated with ovarian parameters around the time of ovulation when cows are fed excess dietary CP. However, more research is warranted to elucidate how blood plasma AA directly impact ovarian parameters and influence reproduction in beef cows.