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Effect of treatment with follicle-stimulating hormone or bovine somatotropin on the quality of oocytes aspirated in the autumn from previously heat-stressed cows
Year:
2002
Source of publication :
Journal of Dairy Science
Authors :
Braw-Tal, Ruth
;
.
Volume :
85
Co-Authors:
Roth, Z., Department of Animal Science, Faculty of Agriculture, Hebrew University, Rehovot 76100, Israel
Arav, A., Institute of Animal Science, Agricultural Research Organization, Bet Dagan 50250, Israel
Braw-Tal, R., Institute of Animal Science, Agricultural Research Organization, Bet Dagan 50250, Israel
Bor, A., Institute of Animal Science, Agricultural Research Organization, Bet Dagan 50250, Israel
Wolfenson, D., Department of Animal Science, Faculty of Agriculture, Hebrew University, Rehovot 76100, Israel
Facilitators :
From page:
1398
To page:
1405
(
Total pages:
8
)
Abstract:
Conception in dairy cows during autumn remains low even after summer temperatures decline. This is possibly a residual effect of heat stress on oocyte quality. Lactating Holsteins previously heat-stressed during summer were used in two experiments (n = 8 and 16 cows) in autumn to examine hormonal strategies for improving quality of oocytes. Follicles (3 to 8 mm in diameter) were aspirated by the ovum pick-up procedure on d 4 of two consecutive estrous cycles of treated and control cows. Oocytes were classified morphologically, matured in vitro, chemically activated, and cultured for 8 d. In Experiment 1, FSH (2 x 200 mg, at a 12-h interval) was injected on d 5 and 12 of cycle 1 (treated cycle). Before FSH, the percentage of good quality oocytes (grade I) and the cleavage rate averaged 52 and 24%, respectively, in both groups. During the FSH-treated cycle, more 6- to 9-mm follicles were observed. In the subsequent cycle, rates of grade I oocytes and cleavage were significantly higher in FSH-treated than in control cows (89 vs. 51% and 85 vs. 31%, respectively). In Experiment 2, recombinant bovine somatotropin (bST, 500 mg) was injected on d 4 and 18 of the treated cycle. The bST treatment increased the number of 3-to 5-mm follicles. Before bST, grade I (39%) and cleaved oocytes (40%), were similar across treatment groups. In the subsequent cycle, the percentage of grade I oocytes was significantly higher in treated than in control cows (72 vs. 26%), but cleavage rates were similar. Neither FSH or bST improved blastocyst formation, and regardless of treatment, few blastocysts were formed. Treatment with bST improved oocyte morphology, whereas FSH improved both oocyte morphology and cleavage rates during autumn following summer heat stress.
Note:
Related Files :
Animal
Animals
Blood
cattle
cows
drug effect
Female
Follicle Stimulating Hormone
heat stress
season
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DOI :
Article number:
Affiliations:
Database:
Scopus
Publication Type:
article
;
.
Language:
English
Editors' remarks:
ID:
29639
Last updated date:
02/03/2022 17:27
Creation date:
17/04/2018 00:48
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Scientific Publication
Effect of treatment with follicle-stimulating hormone or bovine somatotropin on the quality of oocytes aspirated in the autumn from previously heat-stressed cows
85
Roth, Z., Department of Animal Science, Faculty of Agriculture, Hebrew University, Rehovot 76100, Israel
Arav, A., Institute of Animal Science, Agricultural Research Organization, Bet Dagan 50250, Israel
Braw-Tal, R., Institute of Animal Science, Agricultural Research Organization, Bet Dagan 50250, Israel
Bor, A., Institute of Animal Science, Agricultural Research Organization, Bet Dagan 50250, Israel
Wolfenson, D., Department of Animal Science, Faculty of Agriculture, Hebrew University, Rehovot 76100, Israel
Effect of treatment with follicle-stimulating hormone or bovine somatotropin on the quality of oocytes aspirated in the autumn from previously heat-stressed cows
Conception in dairy cows during autumn remains low even after summer temperatures decline. This is possibly a residual effect of heat stress on oocyte quality. Lactating Holsteins previously heat-stressed during summer were used in two experiments (n = 8 and 16 cows) in autumn to examine hormonal strategies for improving quality of oocytes. Follicles (3 to 8 mm in diameter) were aspirated by the ovum pick-up procedure on d 4 of two consecutive estrous cycles of treated and control cows. Oocytes were classified morphologically, matured in vitro, chemically activated, and cultured for 8 d. In Experiment 1, FSH (2 x 200 mg, at a 12-h interval) was injected on d 5 and 12 of cycle 1 (treated cycle). Before FSH, the percentage of good quality oocytes (grade I) and the cleavage rate averaged 52 and 24%, respectively, in both groups. During the FSH-treated cycle, more 6- to 9-mm follicles were observed. In the subsequent cycle, rates of grade I oocytes and cleavage were significantly higher in FSH-treated than in control cows (89 vs. 51% and 85 vs. 31%, respectively). In Experiment 2, recombinant bovine somatotropin (bST, 500 mg) was injected on d 4 and 18 of the treated cycle. The bST treatment increased the number of 3-to 5-mm follicles. Before bST, grade I (39%) and cleaved oocytes (40%), were similar across treatment groups. In the subsequent cycle, the percentage of grade I oocytes was significantly higher in treated than in control cows (72 vs. 26%), but cleavage rates were similar. Neither FSH or bST improved blastocyst formation, and regardless of treatment, few blastocysts were formed. Treatment with bST improved oocyte morphology, whereas FSH improved both oocyte morphology and cleavage rates during autumn following summer heat stress.
Scientific Publication
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