Nursing effects on postpartum anestrus in CGB ewes on autumn

Abstract

The main aim of this paper was to study the effects of three different nursing protocols – 24 hours/day (Control), by night (Nocturne) and twice/day for 30 minutes periods (Bi-diary) – on returning to postpartum ovarian cyclicity. Fifty nine adult Portuguese Churra Galega Bragançana ewes were used. All ewes presented eutocia delivery during the first two weeks of October. Nocturne and bi-diary lambs were first separated from their mothers at the age of 1 week. Cyclicity assessment started at the same time by measuring progesterone (P₄) plasmatic levels. Ewes were considered in postpartum anestrus as P₄ levels were lower than 0.5 ng/ml.

Plasmatic levels of P₄ rose over 0.5 ng/ml for the first time about 31.6 ± 10.2 days after partum. Most ewes presented a first short-term Corpus Luteum. Nursing protocol had no significant effect on returning to ovarian cyclicity.