Synchronization of estrus and fertility in beef cattle with two injections of buserelin and prostaglandin

Twagiramungu, H.; Guilbault, L.A.; Proulx, J. G.; Dufour, J. J.

doi:10.1016/0093-691x(92)90126-c

Cited by 65 publications

(31 citation statements)

References 33 publications

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“…This was because the injected GnRH had synchronously terminated most stages of ovarian follicle development to be followed by a synchronized emergence of a new follicle wave leading to the presence of a maturing dominant follicle 7 days after injection [12,13]. These initial studies utilised lactating beef cows that were cycling as well as anestrus and beef heifers.…”

Section: Combinations Of Pgf and Gnrhmentioning

confidence: 99%

Recent Advances in the Synchronization of Estrus and Ovulation in Dairy Cows

Macmillan

2010

J. Reprod. Dev.

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Abstract. Synchronization programs have become standard components in the current breeding management of cows in the dairy herds of most dairy industries. Many are based on protocols that allow timed inseminations (TAI) so as to circumvent the practical difficulties associated with estrus detection. These difficulties are exacerbated in modern herds of high producing cows either because of increasing herd size in which individual animal monitoring is difficult and often subjective, or because small intensively managed herds are milked in robotic systems that minimize animal: staff interactions. Additional reasons arise from high producing cows having less obvious symptoms of estrus, partly because of housing systems combined with intensive feeding and milking, partly because of higher metabolic clearance rates of reproductive hormones like estradiol and partly because of the increasing prevalence of prolonged post-partum anestrus and reproductive tract pathology. The most recently developed programs include protocols for resynchronization following first or subsequent inseminations. These re-synchronization protocols may involve selected forms of hormonal intervention during the diestrous and pro-estrous periods following TAI, or following pregnancy diagnosis by ultrasound from 28 days after TAI. The latter form of re-synchronization has become increasingly important with the recognition that late embryonic/early foetal death has become a major factor compromising the reproductive performance of high producing Holstein cows in many dairy industries. Although cows detected in estrus without any hormonal treatment before insemination have higher conception rates than those inseminated following synchronization and TAI, the low detection rates combined with embryonic death means that intervals from calving to conception (days open) are usually less when synchronization programs have been successfully implemented. One of the significant factors affecting a program's success is the compliance rate that may sometimes be less than 70%. Almost all programs involve strategically timed injections of prostaglandin F2α (PGF) and gonadotropin releasing hormone (GnRH). Injections of an estradiol ester and progesterone supplementation per vaginum may be included in some programs. The basic program is the "Ovsynch" regimen. Numerous variations have been tested and developed. Many involve increasingly complex protocols that increase the risk of non-compliance, none has consistently achieved conception rates that exceed 40% and few have reduced the incidence of embryonic death. These synchronization programs are the best that are currently available. They have not been able to overcome the consequences of lowered fertility associated with high levels of milk yield, forms of nutrition and environmental factors like heat stress that have profound effects on the physiology and metabolism of the high producing dairy cow.

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Section: Combinations Of Pgf and Gnrhmentioning

confidence: 99%

Recent Advances in the Synchronization of Estrus and Ovulation in Dairy Cows

Macmillan

2010

J. Reprod. Dev.

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“…Therefore, it is necessary to use the progesterone device in combination with prostaglandin F 2α (PGF2α) or estradiol . Estrus can be synchronized by injecting PGF 2α during luteal phase [14,[38][39][40][41][42][43]. However, there is a variation in interval from PGF 2α injection to estrus, and the optimum time for insemination is difficult to be estimated.…”

Section: Synchronization Of Estrusmentioning

confidence: 99%

Development of Ovulation Synchronization and Fixed Time Artificial Insemination in Dairy Cows

Yamada¹

2005

J. Reprod. Dev.

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Abstract.Recently, reproductive management has become more difficult as a result of increased herd size. Problems with missing estrous signs and decrease in conception rate by artificial insemination (AI) performed at wrong timing have caused low AI conception rates. In 1995, ovulation synchronization and fixed-time AI (Ovsynch/TAI) was developed in the USA as a new reproductive technology, which was accepted as an useful reproductive management tool in many countries. However, no information on the use of Ovsynch/TAI was available in Japan. It was, therefore, warranted to show the ovulation rate and conception rate after Ovsynch/TAI using gonadotropin releasing hormone analogue (GnRH-A, fertirelin acetate) and prostaglandin F2α (PGF2α)-THAM, both were commercially available in this country. The conception rate after Ovsynch/TAI has been known to vary among different herds and individuals. Investigation and analysis of factors affecting the conception rate was also warranted to improve the conception rate. A series of experiments were carried out to establish Ovsynch/TAI using domestically produced GnRH-A and PGF2α and to study factors affecting conception rate after Ovsynch protocol. Ovsynch using 100 µg GnRH-A and 25 mg PGF2α were observed using ultrasonography. As a result, a high synchronization rate of ovulation at 16 to 20 h after the second GnRH injection was confirmed. The conception rate after Ovsynch/TAI was compared in 87 cows with the conception rate after AI at estrus induced by PGF2α (139 cows). Conception rate after Ovsynch/TAI was higher than the figure after AI at induced estrus (59.1% vs 20.9%, P<0.05). The dose of GnRH-A was also studied and a practical dose of GnRH-A was found to be 50 µg per cow. To clarify some factors affecting the conception rate after Ovsynch/TAI, 1,558 cows were investigated for the state of their ovaries, days after calving, parity, season, ovarian cyclicity postpartum and nutritional state at the day of Ovsynch. The overall conception rate after Ovsynch/ TAI was 51.5%. Fifty-six cows (3.6%) showed estrus at 6 to 7 d after the first injection of GnRH-A. The conception rate after Ovsynch/TAI was low in cows that were 40 to 60 d postpartum, those in their 5th lactation or more, those bred in July to August, and those recovering ovarian cyclicity later than 56 d postpartum. The conception rate after Ovsynch/TAI was high in cows in which body condition score (BCS) was 3.75 at dry period and 3.0 at the day of Ovsynch. In conclusion, Ovsynch/TAI is an effective tool for the reproductive management of dairy cows. A steady and sufficient conception rate after Ovsynch/TAI could be expected by taking the factors affecting the conception rate into the consideration. Key words: Artificial insemination, Dairy cow, Estrus, Ovulation synchronization (J. Reprod. Dev. 51: [177][178][179][180][181][182][183][184][185][186] 2005) here are about 1,730,000 dairy cattle in Japan and half of the cattle for breeding are in Hokkaido. Nakashunbetsu, a town in the Nemuro district of Hokkaido,...

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“…Thus, treatment of anestrus is one of the crucial measures to be taken to improve reproductive performance in po stpart um s uckled beef cow s. Var io us procedures have been developed to either induce or synchronize ovulation in suckled beef cows [2,3]. As an option among several different breeding programs, ovulation synchronization protocol using two injections of GnRH and prostaglandin F2α (PGF) and timed artificial ins emination (Ovsynch protocol) has been applied worldwide in beef cows [4][5][6][7] as well as in dairy cows [8][9][10][11], and acceptable conception rates have been obtained. A first dose of GnRH curtails follicular development and induces the emergence of a new follicular wave.…”

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confidence: 99%

Comparison of the Effectiveness of Ovulation Synchronization Protocol in Anestrous and Cycling Beef Cows

Osawa

Morishige

Ohta

et al. 2003

Journal of Reproduction and Development

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Abstract. Applicability of ovulation synchronization protocol using GnRH and PGF2α (PGF) injection to anestrous beef cows remains controversial. We compared the effectiveness of the protocol in the anestrous stage of the beef cow with that in the cycling stage using the same animals. Ovaries of five Japanese Black and three Japanese Shorthorn cows were ultrasonographically examined, and blood samples were collected daily for hormonal analyses. Each animal received the protocol twice (Day -6 to -8: GnRH, Day 0: PGF, Day 2: GnRH). Additional blood samples were taken before and after GnRH injection for LH and FSH measurements to evaluate the pituitary function. For the ovarian status at the onset of the protocol cows were divided into anestrous (n=8) and cycling (n=8) stages. There was no significant difference in size of the dominant follicle at the first and second GnRH injections, and in the magnitude of the pituitary response to GnRH between the two stages. However, the size of the corpus luteum and progesterone concentrations at the PGF injection in the anestrous stage were significantly smaller and lower (P<0.01), respectively, and ovulation synchronization rate in the anestrous stage was significantly lower (P<0.05) than in the cycling stage. In conclusion, ovulation synchronization protocol in anestrous beef cows has limited effectiveness.

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Synchronization of estrus and fertility in beef cattle with two injections of buserelin and prostaglandin

Cited by 65 publications

References 33 publications

Recent Advances in the Synchronization of Estrus and Ovulation in Dairy Cows

Recent Advances in the Synchronization of Estrus and Ovulation in Dairy Cows

Development of Ovulation Synchronization and Fixed Time Artificial Insemination in Dairy Cows

Comparison of the Effectiveness of Ovulation Synchronization Protocol in Anestrous and Cycling Beef Cows

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