Effects of parity, dietary lasalocid, fat supplementation, and sex of calf on postpartum profiles of progesterone, 13-14-dihydro-15-keto-prostaglandin F2a and follicular development in Brahman cows /
Multiparous Brahman cows (Exp.1, n=68) were used to evaluate the effects of dietary rice bran (R), lasalocid (L), or a combination of both rice bran and lasalocid (RI,), and sex of calf (SC) during the postpartum period. Hormone profiles, body condition (BCS) and weight (BW), follicular populations...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1999.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=733668381&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Multiparous Brahman cows (Exp.1, n=68) were used to evaluate the effects of dietary rice bran (R), lasalocid (L), or a combination of both rice bran and lasalocid (RI,), and sex of calf (SC) during the postpartum period. Hormone profiles, body condition (BCS) and weight (BW), follicular populations and postpartum interval were measured. PGFM concentrations from d 1 to d 7 after calving (PP) and P4 concentrations on d 7 and d 10 after estrus were not influenced (P>.10) by diet or SC. Changes in BW and BCS were not affected (P>.10) by diet. The number of medium size follicles tended to be greater (P<.06) in control (C) than in L or RL on d 21 PP, while L tended to have a greater mean number of small follicles. The interval to return to estrus with a functional CL was greater (P<.02) in R (70.6%) and L (76.5%) by 60 d than for C (52.9%) or RL (25.0%). Normal first estrous cycles were less likely to be exhibited (P<.07) in RL than in C, R, or L. Intervals from calving to: CL formation, functional CL, and first P4>1 ng/ml were longer (P<.02) in RI, than C, R, or L. Combining increased dietary fat (5.2%) with lasalocid lengthened the time to reproductively important events. The effects of parity status (Exp.2) on postpartum hormonal profiles, changes in body condition and weight, follicular populations and postpartum interval in Brahman cattle was determined with multiparous (n=8) and primiparous (n=6) cows. On d 7 PP, PGFM concentrations tended (P<.10) to higher in the primiparous group. Plasma P4 concentrations on d 7 and d 10 after estrus and changes in BW and BCS through d 42 PP and at estrus were not affected (P>.10) by parity status. From d 1 PP to weaning, ADG was greater (P<.04) for the primiparous group. Calf performance was not influenced (P>.10) by parity status. The number of medium size follicles (4.1-6 nun) through d 49 PP was greater (P<.01) in the primiparous group. The size of the ovulatory follicle (P<.01) and the number of follicles in the cohort (P<.05) was reduced in cows exhibiting abnormal first estrus cycles. Interval to reclamation of follicular waves (P<.04), estrus (P<.03), and to development of an 8mm or 10mm follicle (P<.01) was greater in the primiparous group. Follicular development and waves began later after calving in primiparous cows, but the interval from these events to estrus was similar to primiparous cows. |
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| Item Description: | Vita. "Major Subject: Physiology of Reproduction". In title symbols are used. |
| Physical Description: | xii, 92 leaves ; 28 cm. Issued also on microfiche from University Microfilm Inc. |
| Bibliography: | Includes bibliographical references (leaves 80-91). |