Produção Nacional
Revisado por pares
Although it induces synchronized ovulation, hCG reduces the fertility of Santa Ines ewes submitted to TAI
2018; UNIVERSIDADE FEDERAL DE MINAS GERAIS; Volume: 70; Issue: 1 Linguagem: Inglês
10.1590/1678-4162-9679
ISSN1678-4162
AutoresL.M.K. Dias, J. N. S. Sales, Priscila Viau Furtado, Marina Berrettini Paes de Barros, Samir Saldanha Nicolau, L.M.S. Simões, Nadja Gomes Alves, Maria Augusta Alonso, Renato Valentim, Cláudio Alvarenga de Oliveira,
Tópico(s)Effects of Environmental Stressors on Livestock
ResumoABSTRACT The aim of this study was to evaluate hCG treatment on ovarian response and on pregnancy rate using a 9-day oestrus synchronization protocol in Santa Ines ewes. On a random oestrus cycle day, ewes received an intravaginal progesterone device (Primer-PR®, Tecnopec, Brazil). Nine days later (Day 9), 30µg of d-cloprostenol (Prolise®, Syntex, Argentina) and 250IU of eCG (Folligon®, Intervet, Brazil) were administered and the progesterone device was removed. This moment, the ewes were randomly assigned on two groups: Control Group and hCG Group. In the hCG Group, the ewes received 500IU of hCG (Vetecor®, Hertape-Calier, Spain) 24h after device removal. In the Control Group, the ewes did not receive any ovulation inductor. Control and hCG Groups ewes were inseminated 60h and 48h after device removal, respectively. There was no difference between the groups regarding the first ovulatory follicle diameter and the second ovulatory follicle. hCG Group ewes had shorter interval between device removal and ovulation (Control: 79.9±15.4h and hCG: 54.7±4.9h; P=0.001) and more synchronized ovulations. However, the treatment with hCG decreased the pregnancy rate after TAI (P=0,009). In conclusion, hCG administration improves ovulatory synchronisation, but causes a decrease in the pregnancy rate.
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