Resynchronization of estrous cycle with eCG and temporary calf removal in lactating Bos indicus cows

Campos, Jefferson Tadeu; Marinho, Luciana Simões Rafagnin; Lunardelli, Paula Alvares; Morotti, Fábio; Seneda, Marcelo Marcondes

doi:10.1016/j.theriogenology.2013.05.029

Cited by 20 publications

(23 citation statements)

References 22 publications

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“…P4 was administered using a traditional intravaginal device (P4 + EB on D0, removal of the implant + administration of 250 µg of PGF2α + 300 IU eCG + EC D8; insemination of animals 48 hours after removal of the implants) and the study compared heifers, primiparous and multiparous cows lactating. These results were very similar to those observed by Campos et al (2013), who obtained conception rates ranging from 47 to 54% after the first FTAI in multiparous Nelore cows.…”

Section: Animal Categorysupporting

confidence: 91%

Pregnancy rate evaluation in lactating and non-lactating Nelore cows subjected to fixed-time artificial insemination using injectable progesterone

Campos

Morotti

Bergamo

et al. 2016

SCA

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Most fixed-time artificial insemination (FTAI) protocols utilize progesterone (P4) as a hormonal source to achieve synchronization of estrus in cattle. The use of an injectable P4 source to control estrus would be an interesting pharmacological strategy owing to the practicality of parenteral application. However, the effects of injectable P4 on estrus cycle control in cattle remain poorly studied. In particular, no existing studies have investigated the effect of injectable P4 on the fertility of cows subjected to FTAI. The aim of this study was to evaluate the pregnancy rate of lactating and non-lactating Nelore cows subjected to FTAI with injectable P4. Of the 422 non-lactating cows in this study, 162 (38.3%) became pregnant by 60 days post-FTAI. In the lactating group (n = 516), 166 (32.1%) were pregnant by 60 days after treatment with injectable P4. The proportions of lactating and non-lactating cows becoming pregnant were compared using the chi-square test, adopting a significance level of P < 0.05. It was found that the pregnancy rate of the cows subjected to FTAI with injectable P4 was influenced by lactation status. Lactating cows had lower reproductive performance, possibly because of their higher nutritional requirements. However, the use of injectable P4 shows promising results and may prove to be a useful strategy in large-scale livestock production. Key words: Injectable progesterone. Lactating cow. Non-lactating cows Synchronization of ovulation. Pregnancy rate. ResumoEm bovinos a maioria dos protocolos de inseminação artificial em tempo-fixo (IATF) utiliza a progesterona (P4) como base hormonal para a sincronização do estro. A utilização de uma fonte de P4 injetável para este controle do ciclo estral poderia ser uma estratégia farmacológica interessante, devido à praticidade de uma aplicação parenteral. O efeito da P4 injetável no controle da dinâmica folicular em bovinos tem sido pouco estudado, e até o momento, não há estudos que investigaram o efeito da P4 injetável na fertilidade de vacas submetidas à IATF. O objetivo do presente estudo foi avaliar a taxa de prenhez de vacas Nelore em lactação e não lactantes, submetidas a um protocolo de IATF a base de

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Section: Animal Categorysupporting

confidence: 91%

Pregnancy rate evaluation in lactating and non-lactating Nelore cows subjected to fixed-time artificial insemination using injectable progesterone

Campos

Morotti

Bergamo

et al. 2016

SCA

View full text Add to dashboard Cite

show abstract

“…Partly this happened because the group GeCGTW showed higher PR by bulls clean up alone and TAI + clean up at the end of the breeding season. In fact, this was confirmed because GeCGEB and GeCGEC displayed no differences between themself at the end of the breeding season (Table 1).Working on five groups of beef cows, Campos et al (2013) administered 300 IU eCG in one group and subjected the other group to eCG + TW, resulting in higher PR, than in other groups using estrus resynchronization protocols. Yelich et al (1995) used TW after the previous use of oral progestin.…”

Section: Resultsmentioning

confidence: 75%

“…The combination of eCG and TW in Bos indicus lactating cows was also used for estrus resynchronization. Campos et al (2013) verified that the association between eCG and more TW was the best protocol for TAI in B. indicus lactating cows. For induced ovulation studies, EC was administered at the time of P 4 removal.…”

Section: Introductionmentioning

confidence: 56%

“…This biotechnology not only provides the advantages of conventional AI, but also includes other benefits such as the ability to perform AI in a large number of animals without estrus observation, and the relatively short duration (Sales et al 2015). Many hormonal protocols related to TAI have been developed for beef cattle in the last decade by using long-acting progesterone (P 4 ), EB, or gonadotropin-releasing hormone (GnRH) on the first day of treatment (Pursley et al1995;Wheaton and Lamb 2007), followed by eCG, EC, or even temporary weaning (TW), when the intravaginal P 4 is removed (day 8 after the start of the protocol) (Campos et al 2013;Barreiros et al 2014). To improve ovarian follicle quality, ovulation, and pregnancy rate (PR), eCG was administered on the day of P 4 removal in TAI protocols Sá Filho et al 2010;Campos et al 2013).…”

Section: Introductionmentioning

confidence: 99%

“…Many hormonal protocols related to TAI have been developed for beef cattle in the last decade by using long-acting progesterone (P 4 ), EB, or gonadotropin-releasing hormone (GnRH) on the first day of treatment (Pursley et al1995;Wheaton and Lamb 2007), followed by eCG, EC, or even temporary weaning (TW), when the intravaginal P 4 is removed (day 8 after the start of the protocol) (Campos et al 2013;Barreiros et al 2014). To improve ovarian follicle quality, ovulation, and pregnancy rate (PR), eCG was administered on the day of P 4 removal in TAI protocols Sá Filho et al 2010;Campos et al 2013). Peres et al (2009) reported the enhancing effect of eCG on serum P 4 , ovulation, and PR in non-lactating Bos indicus cows.…”

Section: Introductionmentioning

confidence: 99%

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