Puberty in four genotypes of female goats in Northeast Brazil.

Abstract

Abstract: This experiment was carried out with 99 female kids from four native brceds (Canind& Marota, Moxotó, and Repartida, raised on native pasture at Lhe l3razilian National (loat Research Center, Ceará State, Northeast Brazil. Body weight of the animais were taken at birth, and at four-week intervais until each female kid showed the first puberal estrus. Between 40-60 hours after puberal estrus was detected using teaser bucks, the ovaries of each female kid were observed by laparotomy to determine the number of corpora albicantia and/or corpora hemorrhagica, as an estimate of the occurrence and rate of prepuberal and puberal ovulation, respectively. The overail mean age and live body weight at puberty was 3616±69 days and 12.6±0.2 kg, respectively. I3reed or type of birth did not affect sigrnficaniiy (P>0.05) the age and weight at puberty. The ovulation rate at prepuberal period and at puberal estrus was 1.00 and 1.04, respcctively (P>0.05). Forty percent of the female kids ovulated prior to puberal estrus and 100% ovulated at puberal estrus. Ovulation occurred more frequentely m the right than iii the Ieft ovary at prepuberal (P0,05) a idade e o peso a puberdade. As taxas medias de ovulacao, no periodo pre-puberal e a puberdade, foram 1,00 e 1,04, respectivamente (P>0,05). Aproximadamente 40,0% das cabritas tinham ovulado antes de apresentarem o primeiro estro clinico, enquanto 100,0% delas ovularam a puberdade. A ovulacao ocorreu com maior frequencia no ovario direito do que no esquerdo, no periodo pre-puberal (P<0,01) e a puberdade (P<0,05)