Control of estrus and ovulation in beef heifers and cows

Until recently, labor required to detect estrus for individual cows or heifers in a herd was the primary reason beef producers viewed artificial insemination as impractical. However, improvements in methods to control estrus and ovulation in beef heifers and cows are now expanding the use of artificial insemination by reducing the time required to detect estrus or eliminating estrus detection entirely. These methods evolved as a result of expanded understanding of the bovine estrous cycle and improved ability to effectively manipulate both follicular waves and luteal lifespan. Modern protocols are now capable of facilitating fixed time artificial insemination in beef cattle through orchestrated use of progestins, gonadotropin releasing hormone, and prostaglandin. These strategies offer effective control of estrus and ovulation in estrous cycling females and are also capable of inducing an ovulatory estrus in high percentages of peripubertal heifers and anestrous postpartum cows ...