Effect of oestrus synchronization protocols and energy supplementation on reproduction of sheep

A study was conducted during August-September 2016 to evaluate the effect of different oestrus synchronization protocols and energy supplementation on biochemical, hormonal and fertility traits in Magra sheep. Adult Magra ewes (n=40) maintained at Arid Region Campus, ICAR-CSWRI, Bikaner were equally divided into five groups. The treatments were bypass fat with progesterone sponge + Inj. PGF 2α 24 h. before withdrawal of sponge (T1: BF-P), T1 + Inj. PMSG 400 IU at the time of sponge withdrawal (T2: BF-Pe), crushed barley with progesterone sponge + Inj. PGF 2α 24 h. before withdrawal of sponge (T3: CB-P), T3 + Inj. PMSG 400 IU at sponge withdrawal (T4: CB-Pe) and progesterone sponge + Inj. PGF2α 24 h before withdrawal of sponge (Control: C-P). Significant increase (P<0.05) in plasma glucose concentration and decrease (P<0.05) in blood urea nitrogen was observed at the time of oestrus compared to the start of experiment in all the treatment groups except control. No significant change was observed in total plasma protein and plasma cholesterol values at the time of oestrus compared to the start of experiment of all the groups. The conception rates in Magra ewes of T1, T2, T3, T4 and C-P groups were 83.33, 100, 100, 71.44 and 57.14% respectively. Significant difference (P<0.05) in progesterone levels was observed at different stages among the groups. It declined at the time of oestrus and increased at 30 days after breeding. It was concluded that the supplementation of energy rich feed and inclusion of eCG in oestrus synchronization protocols improved conception rates in Magra ewes.