Managing the dominant follicle in high-producing dairy cows
Date
2010
Authors
Wiltbank, Milo Charles
Filho, Roberto Sartori
Vasconcelos, José Luiz Moraes
Nascimento, Aníbal Ballarotti
Souza, Alexandre H.
Cunha, A. P.
Sangsritavong, Siwat
Guenther, Jerry N.
Lopez, Hernando
Pursley, James Richard
Journal Title
Journal ISSN
Volume Title
Publisher
Nottingham University
Abstract
Reduced reproductive efficiency has been reported in high-producing dairy cows. Sources of reproductive inefficiency include decreased expression of estrus, increased diameter of the ovulatory follicle and reduced fertility when cows are inseminated after estrus, increased incidence of double ovulation and twinning, and increased pregnancy loss. To overcome some of these inefficiencies, reproductive management programs have been developed that synchronize ovulation and enable effective timed artificial insemination (AI) of lactating dairy cows. Effective regulation of the corpus luteum (CL), follicles, and hormonal environment are critical for optimizing these programs. Recent programs, such as the 5-day CIDR program, Double-Ovsynch, G-6-G, and estradiol benzoate-CIDR programs were designed to more effectively control one or more physiological events. These events include synchronization of a new follicular wave at the beginning of the program, optimization of the circulating progesterone (P4) concentrations and duration of follicular dominance, optimized reductions in P4 and increases in circulating estradiol (E2) concentrations during the preovulatory period, and tightly synchronized ovulation of a follicle of optimal size and fertility for implementation of timed AI. The success of these programs has been remarkable, although there is substantial variability in effectiveness due to environmental, management, nutritional, genetic, and disease factors as well as potential variability in some aspects of reproductive physiology among commercial dairy farms. Future programs will optimize the reproductive physiology while simplifying the protocol implementation and also match specific reproductive management protocols to specific farms and even specific cows (for example primiparous vs. multiparous).
Description
Bu çalışma, Eylül 2010 tarihleri arasında Anchorage[Alaska]’da düzenlenen 8. International Symposium on Reproduction in Domestic Ruminants’da bildiri olarak sunulmuştur.
Keywords
Time artificial-insemination, Estradiol cypionate, Ovulatory follicle, Estrous-cycle, Reproductive-performance, Ovarian-follicle, Embryo quality, Beef-cows, Chorionic-gonadotropin, Persistent follicles, Agriculture, Reproductive biology, Veterinary sciences
Citation
Wiltbank, M. C. vd. (2010). "Managing the dominant follicle in high-producing dairy cows". ed. Lucy, M. C. vd. Reproduction in Domestic Ruminants VII, Society of Reproduction and Fertility, 67, 231-245.