منابع مشابه
Effect of ACTH-challenge on progesterone and cortisol levels in ovariectomised repeat breeder heifers.
In order to investigate the potential influence of stress as a component of the repeat breeding syndrome, the adrenocortical capacity for steroid production was evaluated in ovariectomised dairy heifers. In repeat breeder heifers (RBH), marginally elevated plasma progesterone levels during oestrus, so-called suprabasal progesterone levels, have earlier been measured and are believed to impair f...
متن کاملPregnancy Rates in Repeat-breeder Heifers Following Multiple Artificial Inseminations during Spontaneous Oestrus
Hormonal asynchronies during oestrus, related to the presence of suprabasal plasma-progesterone (P4) concentrations and a delayed ovulation, interfere with the fertility of repeat-breeder heifers (RBH). Since tubal dysfunction can occur in connection with hormonal asynchronies and constrained availability of fertile spermatozoa at the time of ovulation, the present study tested the hypothesis t...
متن کاملUltrasonographic diagnosis of the retained semen straw in the uterus of a repeat breeder cow
A 6-year-old lactating Holstein cow with a history of repeat breeding syndrome (failed to conceive afterthree artificial inseminations (AI) with fertile semen) was referred to the Veterinary Teaching Hospital of theSchool of Veterinary Medicine, Shiraz University. According to the history, neither abnormal clinical signs,nor uterine discharge had been observed subsequent to AI. The cow had show...
متن کاملClinical Approach to the Repeat Breeder Cow Syndrome
Dairy cattle production requires great intensification, which has been demonstrated to affect negatively on the reproduction. One calf by cow and year is the reproductive objective in these animals. It means that cows must get pregnant after AI, maintain the pregnancy, have parturition after 270 days approx., and wait for a period of 40-50 days to be successfully inseminated again. Nevertheless...
متن کاملRepeat-breeder Females in Beef Cattle: Influences and Causes 1'2
Straightbred and crossbred heifers (165) and cows (241) that were nonpregnant after exposure to fertile bulls for two consecutive breeding periods of 45 to 60 d (repeat breeders) and contemporary cows (102) that had produced a calf in the previous calving season (controls) were placed with bulls and were observed for mating. Repeat-breeder and control females were slaughtered at 2 to 51 d postm...
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ژورنال
عنوان ژورنال: Hereditas
سال: 2009
ISSN: 0018-0661
DOI: 10.1111/j.1601-5223.1971.tb02410.x