The estrus synchronization protocol most commonly used in replacement heifers combines the use of MGA and prostaglandin. Melengestrol acetate (MGA) is a feed additive commonly used in feedlot heifer rations to block estrus activity. Recently, the FDA approved MGA for …
What does a GnRH shot do for the cow at the time of CIDR insertion?
Gonadotropin-releasing hormone (GnRH) will cause the release of LH (luteinizing hormone) from the anterior pituitary within 2 to 4 hours of treatment. Luteinizing hormone stimulates ovulation of a large follicle (at least 10 mm in diameter) if present on the …