2011 (SBTE) 25th Annual Meeting Proceedings - International ...

Acta Scientiae Veterinariae, 2011. 39(Suppl 1): Abstracts - 25th Annual Meeting SBTE-Brazil. August 2011.
A089 FTAI, FTET AND AI
CONCEPTION RATES IN POSTPAR
ARTUM NELORE COWS TREATED
TED WITH ECG BEFORE AND/OR AFTER FIXED-TIME ARTIFICIAL
INSEMINATION
Amanda Prudêncio Lemes 1 , Adnan Darin Pereira Rodrigues 2 , Rogério Fonseca Guimarães Peres 3 , Hugo Borges Graff 4 , Everton Rodolfo Carvalho 5 , Alexandre
Henryli Souza 6 & Roberto Sartori 7
1,7
UNIVERSIDADE DE SÃO PAULO, ESCOLA SUPERIOR DE AGRICULTURA, PIRACICABA, SP, BRAZIL. 2 UNIVERSIDADE ESTADUAL PAULISTA, BOTUCATU, SP, BRAZIL.
3,4,5
AGROPECUÁRIA FAZENDA BRAZIL, BARRA DO GARÇAS, MT, BRAZIL. 6 DEPARTMENT OF DAIRY SCIENCE, UNIVERSITY OF WISCONSIN-MADISON, MADISON, ESTADOS UNIDOS.
The objective of this study was to evaluate synchronization and conception rates in postpartum Nelore cows treated with eCG before
and/or after TAI. Multiparous cows with body condition score (BCS) of 3.03±0.03 (scale from 1 to 5) and kept at pasture were used. Cyclicity
status was assessed based on the presence of corpus luteum detected by ultrasound evaluation in a sub sample of these animals (n = 100). An
incidence of 90% of anestrus was detected at the beginning of treatments at 34.4±0.3 days postpartum. In order to synchronize ovulation for TAI,
the following protocol was used: D0 - intravaginal progesterone device (DIB ® , Syntex S.A., Argentina), 2 mg estradiol benzoate (Gonadiol ® ,
i.m., Syntex S.A.) and 12.5 mg dinoprost tromethamine (Lutalyse ® , i.m., Pfizer Animal Health); D8 - 12.5 mg dinoprost tromethamine, 0.8 mg
estradiol cypionate (ECP ® , i.m., Pfizer Animal Health) and withdrawal of DIB; D10 - AI using semen from three bulls equally distributed
among treatments. Cows were grouped randomly to receive 300 IU eCG (Novormon 5000 ® , Syntex S.A.) on D8 of the protocol (n = 227),
on D24 of the protocol (14 days after AI, n = 229), on D8 and D24 (n = 224), or not to receive eCG (Control, n = 224) in a 2x2 factorial design.
The DIB was used three times and the reuses were made in a balanced way among groups. Ultrasound evaluations were performed on days
7, 30 and 60 after AI. Data were analyzed using PROC GLIMMIX of SAS ® , with the experimental unit “cow” treated as a random variable.
The means are presented as least squares ± SE. When cows were treated with eCG 14 days after AI, there was no improvement in conception
at 30 (41.6±3.7% vs. 42.7±3.6%, P = 0.75) or 60 days (39.8±3.7% vs. 40.2±3.6%, P = 0.93). However, although the use of eCG on D8 of
the protocol did not significantly improve conception rate at 30 days (44.3±3.7% vs. 40.1±3.6%, P = 0.11), this treatment resulted in a greater
synchronization rate (90.9±1.4% vs. 80.5±1.9%, P < 0.0001) and conception rate at 60 days after AI (42.9±3.7% vs. 37.2±3.6%, P = 0.045).
An effect of ECC in the synchronization rate and conception at 30 and 60 days was also observed (P < 0.05). Cows with lower BCS (