Jacobs Journal of Anatomy and Physiology

Effect of GnRH at Estrus and 12-Day Post Matting and Propylene Glycol on Sera Metabolites Concentrations and Ewe Conception Rate

Published on: 2018-06-28

Abstract

In this study GnRH and propylene glycol respectively used as hormonal treatment and to supply precursor material of glucose. Animals (56 crossbred ewes, Arkhamerino-Ghezel (AG) and Arkhamerino-Moghani (AM), 2.5 years old) were classified to 1 control and 3 treatment groups randomly. After estrus detection and before mating, one milliliter of physiological saline (0.9% NaCl, placebo) was administered to each ewe in control group, group 1 were injected with 2.5 ml GnRH and after 2 hours they were mated by ram, group 2 were injected with 5 ml GnRH 12 days after mating, group 3 were received 30 ml propylene glycol for 5 days after mating. Blood samples were taken on 6 d after mating by using vacuum tube. Glucose, urea, phosphorus, total protein, β-hydroxybutyrate (BHBA) and progesterone concentrations in blood serum were measured. Results shows that glucose in AM was significantly higher than AG (P<0.01). Urea and BHBA in AM were significantly (P<0.01) lower than AG. In repeat breeder ewes, progesterone concentration in estrus 2 was significantly (P<0.05) higher than estrus 1, and urea and BHBA concentrations in estrus 2 were significantly (P<0.05) lower than estrus 1. Administration 5 ml of GnRH on day-12 after mating was effective on reproductive performance than others. In conclusion, results showed that only one sheep in GnRH-2.5 ml treatment at estrus and five sheep in GnRH-5 ml on day-12 after mating showed repeat estrus and suggested that using 2.5 ml of GnRH before mating had better effect to prevent of repeat breeder.

 

Keywords

Crossbred Ewe, GnRH, Propylene Glycol, Conception Rate