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Role of plasma progesterone concentration in early pregnancy of the ewe

Authors :
CS Cocks
Iain J. Clarke
F. D. Brien
IA Cumming
Source :
Australian Journal of Experimental Agriculture. 21:562
Publication Year :
1981
Publisher :
CSIRO Publishing, 1981.

Abstract

Eighty-eight maiden and 125 mature Merino ewes were grazed on green irrigated pasture or given dry hay on a fallow area with or without a lupin grain supplement just before and during mating. Progesterone concentrations in peripheral plasma were measured at 12 d after coitus. Progesterone concentration was lower (2.27 vs 2.87 ng/ml, P < 0.001 ) when lupins were fed, and maiden ewes had higher progesterone concentrations than mature ewes (2.75 vs 2.36 ng/ml, P < 0.05). Pregnant ewes had higher progesterone concentrations than non-pregnant ewes (2.77 vs 2.36 ng/ml, P < 0.05), and ewes with two ovulations had higher progesterone concentrations than ewes with a single ovulation (3.13 vs 2.08 ng/ml, P < 0.001). There was an interaction between pasture type and lupin supplement, with lupins depressing progesterone level more on green irrigated pasture (lupins 2.11 ng/ml, no lupins 3.00 ng/ml, P < 0.05) than on dry pasture (lupins 2.45 ng/ml, no lupins 2.74 ng/ml, P < 0.05). The results confirm that a high plane of nutrition at mating lowers progesterone levels in plasma and suggest that this may be a factor in the increase in embryo deaths when ewes are fed lupin grain supplements.

Details

ISSN :
08161089
Volume :
21
Database :
OpenAIRE
Journal :
Australian Journal of Experimental Agriculture
Accession number :
edsair.doi...........005f0ef4da6accc7f68116d7059c19c7
Full Text :
https://doi.org/10.1071/ea9810562