AVIS-IBIS

Birds of Indian Subcontinent

The effect of long photoperiod or bromocryptine treatment on prolactin concentration and fertility in ewe lambs mated at induced oestrus

Publication Type:Journal Article
Year of Publication:1995
Authors:Beck, NFG, Davies, MCG, Davies, B
Journal:Animal Science
Volume:60
Issue:02
Date Published:1995
ISBN Number:1357-7298
Keywords:Corvidae, Corvus, Corvus corone
Abstract:ABSTRACT An investigation was conducted into the effects of increasing plasma prolactin concentration with long photoperiod or suppressing it with bromocryptine on the fertility of ewe lambs. One hundred and twenty dim Forest ewe lambs were divided into three groups: group C was kept as a control; group L was exposed to a long photoperiod (16 h light: 8 h dark) and group B was given daily injections of 1 mg bromocryptine from 12 days before until 21 days after mating. All three groups were mated in late November, 30 days after housing, following progestagen/PMSG treatment. Post-mating prolactin concentrations were significantly higher in group L and lower in group B compared with group C (P > 005). Furthermore, post-mating progesterone concentration was higher in this group compared with those in group C (P > 0 Texel ewe lambs were given treatment C or L. Embryo survival tended to be lower and crown rump length, embryo weight and amniotic sac width were reduced at 25 days post mating in the animals given treatment L, compared with those given treatment C (P < 005). These results suggest that embryo growth and survival is reduced in animals bred under a long photoperiod.
URL:http://dx.doi.org/10.1017/S1357729800008365
Short Title:Animal Science
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