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Description:
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The lack of effective , consistent synchronization protocols for ewes is a barrier to the use of
artificial insemination in sheep . This study compared the estrus and ovulation percentage and
window of synchrony of estrus and ovulation for ewes synchronized with three experimental
protocols . The industry’s current standard protocol using PG600 , an 11 d CIDR and PGF2a
was compared to two alternative protocols utilizing GnRH , a 7 d CIDR and PGF2a . Forty
Suffolk ewes were divided into 5 groups and each group was placed on a different protocol .
Blood sampling began 18 h following CIDR removal and samples were collected every 2 h
for 19 consecutively collections . Mean serum concentrations of LH differed between groups
(P <0 .05 ) from 22 -42 h following CIDR removal . The two protocols using the shorter 7 d
progestin regimen and GnRH to control follicular dynamics resulted in higher estrus and
ovulation rates and an acceptable window of synchrony . |