Follicular development and reproductive hormone changes during postpartum anestrus in suckled beef cows
نویسندگان
چکیده
منابع مشابه
Follicular dynamics during postpartum anestrus and the first estrous cycle in suckled or non-suckled Brahman (Bos indicus) cows.
Brahman (Bos indicus) cows, were selected at 28+/-10 days after calving and analyzed by real time rectal ultrasonography three times a week, in order to evaluate and compare follicular and corpus luteum development during postpartum (PP) anestrus and the first PP estrous cycle under sylvopastoril conditions. Suckling (S, n=11) or non-suckling (NS, n=5) cows were evaluated in a zone of tropical ...
متن کاملQuantification of naloxone binding sites in brains from suckled beef cows during postpartum anestrus and resumption of estrous cycles.
Thirty beef cows, approximately 3 yr of age, were randomly assigned to be slaughtered on d 7, 14, 28, 42 or 56 postpartum. Each cow suckled one calf until slaughter. Data from cows slaughtered on d 42 and 56 were pooled and further classified as anestrous or cyclic based on the presence of a corpus luteum and elevated serum concentrations of progesterone at slaughter. Specific binding of [3H]na...
متن کاملOpioid inhibition of luteinizing hormone secretion during the postpartum period in suckled beef cows.
Recent studies have shown that naloxone (N), an opioid antagonist, increases concentrations of luteinizing hormone (LH) in the postpartum anestrous beef cow. However, the LH response to N was influenced by the postpartum interval. For example, a significant LH response to 200 mg of N occurred on d 42 but not on d 14 or 28 postpartum. The present study was conducted to determine the effect of di...
متن کاملEndocrine changes and ultrasonography of ovaries in suckled beef cows during resumption of postpartum estrous cycles.
Changes in follicular and luteal structures were assessed and concentrations of estradiol and progesterone were measured in 13 Hereford X Angus suckled beef cows during resumption of estrous cycles. Transrectal ultrasonography was used to monitor follicular size, ovulation, and formation and regression of the corpus luteum (CL). The interval from parturition to first postpartum ovulation (FO) w...
متن کاملNorgestomet and gonadotropin-releasing hormone enhance corpus luteum function and fertility of postpartum suckled beef cows.
In Exp. 1,101 suckled beef cows were administered two injections of prostaglandin F2 alpha (PGF2 alpha) 11 d apart. Cows in Group 1 received no additional treatment. Cows in Groups 2 and 3 received 250 micrograms of GnRH plus 47-h calf removal. Cows in Group 3 also received a norgestomet ear implant that was inserted 4 d after the first PGF2 alpha injection and left in situ for 8 d. The second ...
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ژورنال
عنوان ژورنال: Kansas Agricultural Experiment Station Research Reports
سال: 1991
ISSN: 2378-5977
DOI: 10.4148/2378-5977.2204