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- Title
Efecto de la inclusión de gonadotropina coriónica equina en un protocolo de sincronización de la ovulación e IATF en vaquillonas Angus.
- Authors
Butler, A.; Etcheverry, E.; Butler, H. M.; Alberio, R. H.; Bartolomé, J. A.
- Abstract
The objective was to compare estrus expression and pregnancy to TAI in cyclic heifers treated or not with 300 IU of eCG at intravaginal progesterone device (IPD) removal. A total of 1049 heifers with reproductive tract score (STR) 4 and 5 received a 0,5 g IPD and 2 mg of estradiol benzoate (BE). Eight days later, 150 μg of D-Cloprostenol and 0,5 mg of estradiol cypionate (CE) were administered and paint was applied in the lumbosacral area. At this time heifers were randomly assigned to receive 300 IU of eCG (n = 524) or remained as non-treated controls (n = 525). At TAI, 48 h after IPD removal, heifers with more than 50% of paint removed were considered in estrus and the rest received 10,5 μg of busereline acetate. TAI was performed by two technicians using three bulls of proven fertility. Pregnancy diagnosis was conducted at 40 and 120 days. The effect of independent variables (group, STR, bull and inseminator) on dependent variables (estrus expression, pregnancy to TAI and pregnancy losses) was evaluated by multiple logistic regression. Estrus expression was greater (P=0,04) in heifers with STR 5 (65,0%) than in heifers STR 4 (56,4%) and there was no effect of treatment group (P=0,20) and interactions (P>0,10). Pregnancy to TAI was similar (P=0,76) for Treatment group (61,4%) than for Control group (63,2%) and there was not significant effect of STR (P=0,95) and interactions (P>0,10). Pregnancy losses between 40 and 120 days were similar (P=0,22) in the Treatment group (3,1%) and Control group (4,8%). In conclusion, in cyclic Aberdeen Angus heifers using a TAI protocol that includes GnRH in animals not showing estrus, treatment with eCG at the time of progesterone device removal did not affect fertility.
- Subjects
ESTRUS; MAMMAL reproduction; HEIFERS; PROGESTERONE; CORPUS luteum
- Publication
Taurus, 2023, Vol 25, Issue 97, p18
- ISSN
1515-3037
- Publication type
Article