Indução a Maturidade Sexual e Taxa de Prenhez com Progesterona de 3° uso em Fêmeas Nelores de 22 meses / Induction of Sexual Maturity and Prenature Rate with Progesterone of 3rd use in Females Nelores of 22 months

ABSTRACT

The objective of this study was to evaluate if the progesterone device (P4) of 3rd use would be efficientto induce the cyclicity and consequent pregnancy rate in nelore heifers. We used 65 animals with a mean weightof 338 kg. All kept in the same environmental and handling conditions. The induction of estrus was performed in33 females with P4 implant of 3rd use, thus forming Group 1 (G1 = 33), those that did not receive the implantwere allocated in Group 2 (G2 = 32). Thirty-two days post-induction protocol was performed on all animals forTAI. The data collected were tabulated in electronic spreadsheets and evaluated in the SAS software (2010). TheTAI pregnancy rate was 21.21% (G1) (7/33) and 46.88% (15/32) for (G2) (P < 0.05). Thus suggesting that priorinduction to puberty with P4 device of 3rd use was not effective.