Author:
Smith M. C. A.,Wallace J. M.
Abstract
To investigate the influence of early ovulation after calving on subsequent
fertility, milk progesterone concentrations were monitored twice weekly in
multiparous (n = 87) and primiparous
(n = 60) Holstein/Friesian dairy cattle.
Luteal activity before 21 days post partum was defined as ‘early’.
In multiparous cows, calving-to-conception interval (CCI) was longer, services
per cow were more numerous and conception rate to all inseminations was lower
with early luteal activity (n = 41,
16·8±0·39 days post partum) than with later luteal
activity (n = 46, 37·8±2·09
days post partum); multiparous cows with early luteal activity required more
exogenous fertility treatments and were more likely to fail to conceive by 100
days post partum. In contrast, in primiparous cows, no significant
relationships were detected between early (n =
32) or later (n = 28) luteal activity and the
CCI, number of services per cow or conception rates to all inseminations.
However, primiparous cows that ovulated before 21 days post partum had fewer
normal progesterone profiles. Early ovulation after calving was associated
with reduced pregnancy rates and prolonged CCIs in multiparous but not in
primiparous dairy cows.
Extra keyword: luteal function.
Subject
Developmental Biology,Endocrinology,Genetics,Molecular Biology,Animal Science and Zoology,Reproductive Medicine,Biotechnology
Cited by
66 articles.
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