What question did this study set out to answer?

To examine how severe maternal undernutrition and plasma progesterone concentrations affect embryo survival and morphological development in ewes during early gestation.

February 1, 1982The Journal of Agricultural Science

Effects of maternal nutrition and plasma progesterone concentrations on survival and growth of the sheep embryo in early gestation

View Full Paper

Ask AI

Bookmark

Authors

RPR. A. ParrAgriculture Victoria ICI. CummingDuke University ICIain J. ClarkeThe University of Melbourne

Discussion

Member takes

Implication

Animal experiment demonstrates maternal undernutrition retards early embryonic growth independent of elevated progesterone in sheep, indicating direct nutritional constraints.

Key Points

To examine how severe maternal undernutrition and plasma progesterone concentrations affect embryo survival and morphological development in ewes during early gestation.
Mature Merino ewes (n = 320) were allocated to either maintenance (100% M) or 25% maintenance (25% M) rations starting the day after mating.
On day 4 post-mating, 223 ewes underwent bilateral ovariectomy and received daily intramuscular progesterone injections (5, 10, 15, 20, or 25 mg/day), while 54 sham-operated ewes served as controls.
Embryos were collected and evaluated for survival, crown-rump length, and anatomical developmental stages at day 11 or day 21 after mating.
Severe undernutrition did not alter embryo survival rates despite maternal weight loss (10.7% by day 11 and 15.8% by day 21), but significantly retarded embryonic growth and development at day 21, reducing crown-rump length (5.93 ± 0.139 mm vs 6.39 ± 0.116 mm, P < 0.05).
Embryo survival increased with higher progesterone replacement doses, showing significantly lower survival at 5–10 mg/day compared to 20–25 mg/day on day 11 (P < 0.05).
Ewes fed 25% M rations maintained significantly higher peripheral progesterone concentrations than 100% M ewes (P < 0.001) from both endogenous and exogenous sources, yet these hormone variations did not correlate with the observed growth deficits.

Cite This Study

Parr et al. (1982) studied this question.

synapsesocial.com/papers/6a931c42d240de4e33e4bbb1 https://doi.org/10.1017/s0021859600041083

View Full Paper

Ask AI

Bookmark

Implication

Animal experiment demonstrates maternal undernutrition retards early embryonic growth independent of elevated progesterone in sheep, indicating direct nutritional constraints.

Effects of maternal nutrition and plasma progesterone concentrations on survival and growth of the sheep embryo in early gestation

Discussion

Member takes

Implication

Key Points

Cite This Study

Effects of maternal nutrition and plasma progesterone concentrations on survival and growth of the sheep embryo in early gestation

Discussion

Member takes

Implication

Key Points

Cite This Study

Also Consider

Also Consider