Sincronização de estro com CIDR reutilizado em cabras lactantes da raça Toggenburg tratadas com somatotropina bovina recombinante (r-bST)

Abstract

Sincronização de estro com CIDR reutilizado em cabras lactantes da raça Toggenburg tratadas com somatotropina bovina recombinante (r-bST)[ RESUMOAvaliou-se a resposta de cabras tratadas com r-bST no protocolo de sincronização de estro. Foram utilizadas 26 cabras Toggenburg, divididas em dois tratamentos: T1 (n=13), tratadas com quatro injeções de 250mg de rbST, a intervalos de 14 dias, e T2 (n=13), tratadas com solução salina (controle). Na semana seguinte à última injeção da r-bST, colocou-se o dispositivo intravaginal com progesterona (dia 0), previamente utilizado por cinco dias, e injetou-se PGF 2 (22,5µg) nos animais dos dois tratamentos, e o dispositivo foi retirado no dia 6. Todas as fêmeas em estro foram submetidas à monta natural. A porcentagem de animais em estro e a taxa de gestação foram 76,9 e 70,0 e 84,6 e 72,7%, no T1 e T2, respectivamente. Não houve diferença (P>0,05) na duração do estro, no intervalo tratamento-início do estro, no número de ovulações, nos intervalos: início e final do estro à ovulação e retirada do dispositivo à ovulação entre os animais dos dois tratamentos. O diâmetro médio dos folículos ovulatórios das fêmeas não diferiu (P>0,05). Durante a permanência do dispositivo, as concentrações séricas de progesterona apresentaram valores semelhantes (P>0,05) entre as cabras de T1 e T2. A r-bST não afetou a sincronização de estro.Palavras-chave: caprino, dispositivo intravaginal, estro, taxa de gestação 2 (22.5µg) ABSTRACT The response of goats treated with r-bST in the estrous synchronization protocol was evaluated. Twenty-six Toggenburg females were divided in two treatments: T1 (n=13) treated with four injections of 250mg r-bST, at 14 days intervals, and T2 (n=13) treated with saline solution (control). The intravaginal device previously used by five days was inserted (day 0) one week after the last injection of r-bST and PGF

Using the same CIDR up to three times for estrus synchronization and artificial insemination in dairy goats

“…In the present study, the mean estrus onset time was similar to Bitaraf et al (2008), who reported an interval of 21.7  0.4h. However, it was shorter than the intervals reported by Guido et al (1999) Although those authors used CIDR for estrus synchronization in goats, the shorter interval from CIDR removal to onset of estrus in this study can be explained by the eCG doses used in each treatment.…”

“…This demonstrates that 9-day protocols with new and reused CIDR can provide efficient estrus synchronization programs, and that these treatments could be used for fixed-time AI programs. The relationship between the early onset of estrus, ovulation and pregnancy rates after AI programs are in agreement with Baril et al (1993) and Romano (2004). Both reports showed that when goats exhibited estrus until 30h after progestagen treatment, a fertility rate of 65% was observed following AI using frozen-thawed semen, but when estrus was observed at intervals of 49 or 72h after hormone treatment, a pregnant goat rate of only 25% was verified (BARIL et al, 1993).…”

“…An efficient pregnancy rate is closely linked to the synchronization of ovulations obtained in treated females. In goats, estrus synchronization is commonly performed with vaginal sponges impregnated with fluorogestone (FGA) (FERNANDEZ-MORO et al, 2008;FREITAS et al, 1996) or medroxyprogesterone acetates (MAP) LEHLOENYA et al, 2005), or using controlled internal drug release (CIDR) devices impregnated with progesterone (AMORIM et al, 2008;MENCHACA et al, 2007). All of these intravaginal devices are Acta Scientiarum.…”

“…For this reason, some researchers such as Guido et al (1999) and Amorim et al (2008) have evaluated the repeated use of CIDR in order to reduce costs without altering reproductive performance. Moreover, these researchers have used this device for up to two consecutive times, without significantly reducing protocol cost.…”