Status of Estrus Synchronization in Nepal

Abstract
| Estrus synchronization refers to manipulating the estrous cycle or inducing heat in a vast number of females in a given time period. Ovulation can be controlled by interrupting or influencing the wave-like follicular growth pattern. Estrus synchronization is achieved by shortening or prolonging the luteal phase using prostaglandins or exogenous progestogens, respectively. The selection of protocol depends on the assessment of resources, including facilities, labor, experience, and budget. PGF2 α induces luteal regression followed by estrus and ovulation in cows when administered during the luteal period. Progestin suppresses the activity of the ovary and inhibits the dominant follicle maturation due to the suppression of both FSH and LH. Gonadotropin-releasing hormone or an analog is administered with PGF2 α to estrous- cyclic and noncyclic cattle disrupts the patterns of follicular growth, inducing ovulation on a large follicle. To select and successfully implement the estrus synchronization regime in animals’ proper knowledge of the hormonal profile and functional structure prevalent in ovaries in stages of estrus. Various protocols are available based on the hormone used, route of administration, requirements for heat detection, number of hormone injections, number of cattle handled, and injection time. Increased labor and upfront cost of hormone treatment, standard degree of supervision, and decent handling facilities are some of the drawbacks of this technique. Successful estrus synchronization necessitates optimum nutrition, a good body condition score, the best semen quality, general health, and an efficient estrus detection technique.