Incidence of short estrous cycles after weaning in beef cows (1979)

Ward, S.J.; Odde, K. G.; Kiracofe, G.H.; McKee, M.

doi:10.4148/2378-5977.2609

Cited by 2 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Estrous cycles of reduced length have been reported in cows after the first postpartum estrus (Macmillan and Watson, 1971;Hansen andHauser, 1980, Odde et al, 1980;Ramirez-Godinez et al, 1980, 1981. Approximately 80% of the postpartum anestrous cows that exhibited estrus within 10 d after weaning their calves had estrous cycles of 7 to 12 d in length with a short serum progesterone rise after the first estrus (Ward et al, 1979;Odde et al, 1980;Ramirez-Godinez et al, 1981). Other researchers have reported that levels of progesterone in serum rise before the first postpartum 153 JOURNAL OF ANIMAL SCIENCE, Vol.…”

Section: Introductionmentioning

confidence: 99%

Endocrine Patterns in the Postpartum Beef Cow Associated with Weaning: a Comparison of the Short and Subsequent Normal Cycles

Ramírez-Godínez

Kiracofe

Schalles

et al. 1982

Journal of Animal Science

View full text Add to dashboard Cite

Levels of luteinizing hormone (LH), follicle stimulating hormone (FSH), progesterone and estradiol-17 beta were measured in five Polled Hereford cows. Blood samples were collected once or twice daily for 5 d, then every 6 h from 1 d before weaning (d 28 to 38 postpartum) until 10 d after the second postweaning estrus. Blood samples were again collected at daily intervals until the third postweaning estrus. All cows exhibited estrus within 4 d after weaning, a second estrus 8 to 10 d after the first and a third estrus 16 to 23 d after the second. All cows had peaks in serum concentrations of LH during the first (22.6 to 81.7 ng/ml) and second (4.4 to 149.0 ng/ml) postweaning estrus. Mean levels of LH in serum during the peak and the area under the LH curve during the first and second postweaning estrus did not differ. Serum levels of LH and FSH during the first 4 d of the short cycle did not differ from LH and FSH levels the first 4 d of the subsequent normal cycle. Levels of LH in serum for 4 d before the first LH surge, associated with the first postweaning estrus, did not differ from levels of LH found 4 d before the second Lh surge, associated with the second postweaning estrus. However, serum levels of FSH during the 4 d before the first ovulatory LH surge were lower (P = .05) than those observed during the 4-d period before the second ovulatory surge of LH. Progesterone levels were similar the first 6 d after the first and second estrous periods, but were lower after d 6 of the first (short) cycle than after d 6 of the second (normal) cycle. Estradiol peaks of 1.2 to 2.8 pg/ml were detected during the first postweaning estrus and 1.4 to 12.5 pg/ml during the second postweaning estrus, but due to the variability among cows mean levels of estradiol during first estrus did not differ from second estrus. These data agree with previous reports that postpartum anestrous cows had short cycles if they exhibit estrus in response to weaning. The early decline of progesterone after the first estrus apparently did not stem from lack of LH in serum, but the lower levels of FSH observed before this first ovulation may have been an important factor contributing to the reduced life span of the subsequent corpus luteum.

show abstract

Section: Introductionmentioning

confidence: 99%

Endocrine Patterns in the Postpartum Beef Cow Associated with Weaning: a Comparison of the Short and Subsequent Normal Cycles

Ramírez-Godínez

Kiracofe

Schalles

et al. 1982

Journal of Animal Science

View full text Add to dashboard Cite

show abstract

“…Resumption of follicular development, estrus, and first ovulation in postpartum cows usually does not result in a successful pregnancy (Ward et al, 1979;Odde et al, 1980). The luteal phase following first ovulation is characterized by spontaneous early regression of the corpus luteum (CL; Odde et al, 1980).…”

Section: Introductionmentioning

confidence: 99%

Evidence for a systemic embryotoxic effect of early luteal regression in the ewe

Costine¹

View full text Add to dashboard Cite

Evidence for a systemic embryotoxic effect of early luteal regression in the ewe. Beth A. Costine Experiments were performed to determine if a short-lived corpus luteum was embryotoxic in ewes given supplemental progesterone and the route of transfer of embryotoxic products. Mated ewes were lutectomized or sham lutectomized on day 4 after estrus. Following surgery, ewes received saline or PGF 2α through days 6 or 7. Pregnancy rate was reduced after treatment with PGF 2α (P < 0.001) compared to controls and was increased in PGF 2α-treated ewes by lutectomy (P < 0.05). Mated ewes with bilateral ovulations were unilaterally lutectomized, and each uterine horn was ligated to eliminate intercornual flow on day 4 after estrus. Treatment with PGF 2α on day 5 through 8 reduced pregnancy rates (P < 0.01), but embryonic survival did not differ in the uterine horns ipsilateral or contralateral to the regressing CL. The regressing CL is embryotoxic in progesterone-supplemented ewes, and embryotoxic luteal products have been shown to act by non-local pathways. iii ACKNOWLEDGEMENTS I would like to express my gratitude to my family for their involvement in my early animal husbandry aspirations, and for their continued encouragement and support. I would like to thank my mom for not letting my teachers at school be my only educators. Kindergarten through high school she was my private tutor and library. I would like to thank my dad for teaching me responsibility and for giving me biceps. Life would be dull without my brother who taught me how to have fun while doing anything. My "Grammie Costine" not only made my education financially possible, but also is an inspiration by being an educated woman-before it was hip. I am indebted to Dr. Greg Lewis and Dr. Meghan Wulster-Radcliffe for introducing me to research. Meghan spent a great deal of time teaching me the basics and gave me an excellent example to follow.

show abstract

Incidence of short estrous cycles after weaning in beef cows (1979)

Cited by 2 publications

References 0 publications

Endocrine Patterns in the Postpartum Beef Cow Associated with Weaning: a Comparison of the Short and Subsequent Normal Cycles

Endocrine Patterns in the Postpartum Beef Cow Associated with Weaning: a Comparison of the Short and Subsequent Normal Cycles

Evidence for a systemic embryotoxic effect of early luteal regression in the ewe

Contact Info

Product

Resources

About