Ovarian activity in Santa Inês sheep under different types of suckling in semi-arid area of Brazil

Abstract

Aiming to investigate the suckling effect on ovarian activity in postpartum Santa Inês ewes through progesterone levels, it was used 18 females aging between 22 and 72 months. After parturition, the lambs stayed with the dams until the 14th day and from the 15th day they were divided in two treatments: continuous and controlled suckling. The blood collection for progesterone happened each seven days from parturition until the first estrous, and, thereafter, each 4 days until the second estrous. There was a silence ovulatory activity before the first postpartum estrous in 85.70% and 25% of the animals submitted to continuos and controlled suckling, while the occurrence of first estrous in the first group was delayed (37.71±3.34 days) in relation to controlled suckling group (26.12±2.4 days). The progesterone average levels between the parturition and the first estrous postpartum were 2.81±1.58ng/mL versus 1.45±0.59ng/mL, and on estrous were 0.25±0,34ng/mL versus 0,32±0,18ng/mL, for females under continuos and controlled suckling, respectively. The progesterone average levels between the first and the second estrous postpartum were 1.53±0.54ng/mL and 2.50±1.09ng/mL, for females under continuos and controlled suckling, respectively, happened these estrous in 77.7% versus 100% and 66.6% versus 100% for females, in the same order. It is concluded that suckling stimuli has influence on the postpartum ovarian activity in Santa Inês ewes and short and silent cycles are necessaries to normal postpartum ovarian cyclic.