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Endocrine Interrelationships During Early Postpartum In St. Croix Sheep, Richard Michael Anderson
Endocrine Interrelationships During Early Postpartum In St. Croix Sheep, Richard Michael Anderson
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The relationships of estradiol-17-beta, progesterone, and LH in the early postpartum St. Croix ewe were monitored during the breeding season in 1988. A second group of non-postpartum, ovariectomized St. Croix ewes were used to determine non-ovarian levels of progesterone for comparison. Results of this study indicate that:
- The short duration rise in progesterone exhibited by some ewes is indicative of an ovulation.
- Ewes that do exhibit a short luteal phase prior to the first "normal" luteal phase have a longer period from parturition to the first "normal" luteal phase.
- Serum levels of LH increase beginning 3 days postpartum.
- There is …
Comparative Foraging Ecology Of Sheep And Goats In Caatinga Woodland In Northeastern Brazil, Scott L. Kronberg
Comparative Foraging Ecology Of Sheep And Goats In Caatinga Woodland In Northeastern Brazil, Scott L. Kronberg
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Small-ruminant production is an important part of the agricultural economy of northeastern Brazil. However, mild-to-severe undernutrition of livestock is an annual occurrence. Goats can tolerate the marginal forage conditions better than sheep, but the mechanisms underlying their superior tolerance are not understood.
An analysis of animal liveweights at the end of the year-long study indicated that reproducing mixed-race goats gained nearly twice (P<.05) the weight of reproducing hair-sheep of the Santa Ynez breed, and non-reproducing goats gained about 1.2 times more (P<.05) weight than non-reproducing sheep. Daily weight gains of lambs were less (P<.10) than those of kids for their first 80 days of life.
In the wet season, reproducing sheep and goats gained similar (P>.05) weight, while non-reproducing sheep gained more (P≤.05) than non-reproducing goats. Non-reproducing goats had greater (P<.05) forage organic matter intake (OMI) than the corresponding sheep in the two wet periods. In the late-wet period, non-reproducing goats had greater (P<.05) digestible energy intake (DEI) than corresponding sheep did but had similar (P>.05) digestible protein intake (DPI) as sheep.
In the dry …