Resumen de FR 29. Reproductive response of crossbred heifers (Bos indicus x Bos taurus) used as bovine embryo recipient in Venezuelan tropic. I. Racial type
Noris Roa, Tiburcio Linares, Diego R. Barrios Arismendi, Rita Tamasaukas, Morella de Rolo
To evaluate reproductive response and early diagnosis of pregnancy in venezuelan tropic, plasma Progesterone (P4) concentrations were determined by Enzyme Linked Immunosorbent Assay (ELISA) in 47 crossbred (Bos indicus x Bos taurus) recipient heifers in a commercial embryo transfer (ET) program in savanna area of Monagas state, Venezuela. Pregnancy status was confirmed by rectal palpation 60 days after oestrus. Pregnancy rates were 38.3% (18/47) while a 61.7 % stayed open. Simple linear regression and one way analysis of variance indicated that there were not significant differences (P>.05) between plasma P4 concentrations of females which remained pregnant and those which did not on either days 0 (estrus) or 7 (ET). On day 21, the mean ± SD concentrations of P4 in pregnant females was 12.2 ± 2.2 ng/mL being significantly higher (P
