Comparison of Methods for the Synchronization of Estrous Cycles in Dairy Cows. 2. Effects of Progesterone and Parity on Conception

Folman, Y.; Kaim, M.; Herz, Z.; Rosenberg, Miriam

doi:10.3168/jds.s0022-0302(90)78969-2

Cited by 101 publications

(59 citation statements)

References 17 publications

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“…A progesterona presente no dispositivo provavelmente foi suficiente tanto para promover a produção de um ovócito saudável, pois já foi demonstrado a correlação entre a concentração sérica de progesterona antes da inseminação artificial e a subsequente taxa de concepção (Fonseca et al, 1983;Folman et al,1990), como para inibir a ocorrência de ciclo curto nas vacas sem corpo lúteo ao início do protocolo, que estavam em anestro (Fortune, 1994;Rivera et al, 1998).…”

Section: Resultsunclassified

Inseminação artificial em tempo fixo e diagnóstico precoce de gestação em vacas leiteiras mestiças

Barbosa¹,

Jacomini²,

Diniz³

et al. 2011

R. Bras. Zootec.

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RESUMO -Avaliou-se, durante um ano, o desempenho reprodutivo de 94 vacas leiteiras mestiças Bos taurus × Bos indicus submetidas a um programa de reprodução assistida. Um protocolo de inseminação artificial em tempo fixo (IATF) foi executado por meio de dispositivo intravaginal contendo progesterona e das injeções de prostaglandina F2α e de cipionato de estradiol. Por meio de ultrassonografia, entre 7 e 14 dias após as inseminações ou montas controladas, realizou-se a detecção de corpo lúteo nos ovários a fim de determinar a taxa de ovulação e, no 28 o dia, fez-se o diagnóstico de gestação para cálculo da taxa de concepção. Respeitou-se um período mínimo de 34 dias após o parto antes do tratamento. Não houve influência do escore de condição corporal e da presença de corpo lúteo no início do protocolo, nem da reutilização do dispositivo intravaginal e da monta controlada ou inseminação artificial, sobre as taxas de ovulação, concepção e concepção das vacas ovuladas. As taxas de concepção e de concepção das vacas ovuladas foram afetadas negativamente pelo elevado número de dias pós-parto (DPP), ou dias em lactação e pela época quente do ano, primavera/verão. A resposta ao protocolo de inseminação artificial em tempo fixo baseado no uso de progesterona, PGF2α e cipionato de estradiol é prejudicada pelo aumento dos dias em lactação e pela época quente do ano. A condição corporal não afeta a resposta ao protocolo de inseminação artificial, desde que as vacas tratadas apresentem escore acima de 2,25 pontos.Palavras-chave: concepção, eficiência reprodutiva, ovulação, protocolo de sincronização Timed artificial insemination and early pregnancy diagnosis in crossbred dairy cowsABSTRACT -It was evaluated, during a period of one year, the reproductive performance of 94 Bos taurus × Bos indicus crossbred dairy cows submitted to an assisted reproduction program. A timed artificial insemination (TAI) protocol was carried out by using an intra-vaginal progesterone device containing progesterone and through injections with Prostaglandin F2α and estradiol cypionate. By using ultrasound, from 7 to 14 days after inseminations or controlled mattings, detection of corpus luteum in the ovaries was done to determine ovulation rate and, on the 28 th day, diagnosis of pregnancy was carried out for calculation of conception rate. Treatment only started after a 34-day post-partum minimal period. Body condition score, presence of corpus luteum in the beginning of the protocol, reutilization of intra-vaginal device and controlled mating or artificial insemination did not influence rates of ovulation, conception and conception of ovulated cows. Rates of conception and rates of conception of ovulated cows were negatively affected by the higher number of days post partum (DPP), or days in milk and by the warmer seasons of the year, spring/summer. Response to protocol of timed artificial insemination based on the use of progesterone, PGF2α and estradiol cypionate is negatively affected by lactation days and by the warm season of the year. Bod...

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Section: Resultsunclassified

Inseminação artificial em tempo fixo e diagnóstico precoce de gestação em vacas leiteiras mestiças

Barbosa¹,

Jacomini²,

Diniz³

et al. 2011

R. Bras. Zootec.

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show abstract

“…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, the magnitude of P4 concentrations before estrus may be associated with factors that increase the probability of conception. Blood concentrations of P4 during the luteal phase before insemination are associated positively with conception rate [9,7,12,10,26,27]. Increased pregnancy rate was reported after intra vaginal inserts containing P4 were applied to cows that were synchronized with PGF 2α [33].…”

Section: Introductionmentioning

confidence: 99%

Reproductive parameters in Holstein dairy cows treated with three resynchronization methods

Kor¹

2012

IOSJPBS

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Comparison of Methods for the Synchronization of Estrous Cycles in Dairy Cows. 2. Effects of Progesterone and Parity on Conception

Cited by 101 publications

References 17 publications

Inseminação artificial em tempo fixo e diagnóstico precoce de gestação em vacas leiteiras mestiças

Inseminação artificial em tempo fixo e diagnóstico precoce de gestação em vacas leiteiras mestiças

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

Reproductive parameters in Holstein dairy cows treated with three resynchronization methods

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