Effect of post-ovulation nutritional status in ewes on early concept survival and growth in vivo and luteotrophic protein secretion in vitro [sheep]
1994
Wallace, J.M. | Aitken, R.P. | Cheyne, M.A. (Rowett Research Inst., Aberdeen (United Kingdom))
To determine whether high feed intakes after ovulation alter the secretory dialogue between the conceptus and the endometrium, 24 embryos (8-16 cell) from ewes fed maintenance rations were synchronously transferred in singleton on day 3 of the cycle (oestrus, day 0) into the uterus of ewes receiving a high or low plane of nutrition. Embryo survival and conceptus growth were assessed on day 16. A high plane of nutrition after ovulation did not influence embryo survival and development in vivo or luteotrophic protein secretion in vitro despite a reduction in peripheral progesterone concentrations. The results imply that, if a high feed intake affects embryo survival, either it has to reduce progesterone concentrations below those measured in the current study or it acts before the embryo enters the uterus or after the embryo has successfully overcome luteolysis on day 16 of the cycle.
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