TY - JOUR
T1 - Effects of dosage of FSH, vehicle and time of treatment on ovulation rate and prolificacy in ewes during the anestrous season
AU - Knights, M.
AU - Baptiste, Q. S.
AU - Dixon, A. B.
AU - Pate, J. L.
AU - Marsh, D. J.
AU - Inskeep, E. K.
AU - Lewis, P. E.
N1 - Funding Information:
Published with the approval of the Director of the WV Agricultural and Forestry Experiment Station as Scientific Paper No. 2833. We thank Interag Division of DEC International (Hamilton, NZ) and Vetrepharm, Research Inc. (Ottawa, Canada and Athens, Georgia, USA) for supplies of CIDR-G ® and FSH, respectively. Work was supported by the NRSP-7 program of the USDA/FDA, by Hatch Project 321 (NE161) of the WV Agricultural and Forestry Experiment Station, and by a grant from the West Virginia Legislature to support the West Virginia Sheep Management Project. Ewe flocks and assistance were provided generously by Dennis Mitchell, Jeff and Marvin Harsh, and Keith Martin (Elysian Fields Farm). Special appreciation is extended to Douglas Clevenger, Gary Lowe and Jodi Winkler at the Ohio Agricultural Research and Development Center at Wooster, OH and to Georgette Plaugher of the West Virginia Sheep Management Project, Franklin, WV, for assistance in treating animals, care of animals and collection of data.
PY - 2003/10/1
Y1 - 2003/10/1
N2 - Wooster, OH 44691, The effects of dosage of follicle stimulating hormone (FSH), vehicle and time of injection on ovulation rate and prolificacy were evaluated during the anestrous season. Ewes on four farms (n = 445) were treated with a CIDR-G® device for 5 days and exposed to rams upon removal of the insert (CRRI, day 0). A 3 x 2 x 2 factorial arrangement tested effects of dosage of FSH (Folltropin®; 0, 42 or 68 mg NIH-FSH-PI), vehicle (saline:propylene glycol 1:4, v/v [PGL], or 50% polyvinylpyrrolidone K 29-32 [PVP]) and time of injection (12 or 36 h before CRRI). Follicular growth was monitored by ultrasonography in four ewes per treatment at injection of FSH, at CRRI, and on days 1-3 post-CRRI. All ewes were examined by ultrasonography on days 10-14 for ovulation rate, and on days 26-31 and 46-51 for pregnancy and number of embryos. The largest follicle (F1) increased in diameter (mm) between FSH injection (5.3 ± 0.1) and day 1 (6.1 ± 0.1; P < 0.01). The F1 was larger at CRRI (P ≤ 0.05) in ewes receiving 42 than 0 mg FSH, and 68 than 42 mg FSH. The F2 increased in diameter (P < 0.05) from FSH injection (4.7 ± 0.2) to CRRI (5.2 ± 0.2) and to day 1 (5.8 ± 0.2), but was not affected by treatment. Number of small follicles (≤4 mm) did not differ with time or treatment. Number of medium follicles (5 mm) declined (P < 0.05) between FSH (1.5 ± 0.2) and days 1 (0.8 ± 0.2), 2 (0.9 ± 0.2), and 3 (0.5 ± 0.2). Number of large follicles (≥6 mm) increased from FSH (0. 6 ± 0.3) to CRRI (1.4 ± 0.3; P < 0.05), and day 1 (2.3 ± 0.3; P < 0.05), then declined by day 3 (0.6 ± 0.3; P < 0.05). There were more large follicles at CRRI (P < 0.05) with 68 mg (2.1 ± 0.3) or 42 mg (1.6 ± 0.2) than 0 mg (0.5 ± 0.4) FSH. Ovulation rate (mean 2.12 ± 0.05) increased with FSH given 12 h, but not 36 h before CRRI (dosage x time, P < 0.05). Estrous response, conception rate, percentage of ewes lambing or prolificacy did not differ. However, number of corpora lutea not represented by embryos increased with dosage of FSH (P < 0.01; 0.25 ± 0.14, 0.55 ± 0.09, 0.71 ± 0.09 for ewes treated with 0, 42, and 68 mg FSH, respectively).
AB - Wooster, OH 44691, The effects of dosage of follicle stimulating hormone (FSH), vehicle and time of injection on ovulation rate and prolificacy were evaluated during the anestrous season. Ewes on four farms (n = 445) were treated with a CIDR-G® device for 5 days and exposed to rams upon removal of the insert (CRRI, day 0). A 3 x 2 x 2 factorial arrangement tested effects of dosage of FSH (Folltropin®; 0, 42 or 68 mg NIH-FSH-PI), vehicle (saline:propylene glycol 1:4, v/v [PGL], or 50% polyvinylpyrrolidone K 29-32 [PVP]) and time of injection (12 or 36 h before CRRI). Follicular growth was monitored by ultrasonography in four ewes per treatment at injection of FSH, at CRRI, and on days 1-3 post-CRRI. All ewes were examined by ultrasonography on days 10-14 for ovulation rate, and on days 26-31 and 46-51 for pregnancy and number of embryos. The largest follicle (F1) increased in diameter (mm) between FSH injection (5.3 ± 0.1) and day 1 (6.1 ± 0.1; P < 0.01). The F1 was larger at CRRI (P ≤ 0.05) in ewes receiving 42 than 0 mg FSH, and 68 than 42 mg FSH. The F2 increased in diameter (P < 0.05) from FSH injection (4.7 ± 0.2) to CRRI (5.2 ± 0.2) and to day 1 (5.8 ± 0.2), but was not affected by treatment. Number of small follicles (≤4 mm) did not differ with time or treatment. Number of medium follicles (5 mm) declined (P < 0.05) between FSH (1.5 ± 0.2) and days 1 (0.8 ± 0.2), 2 (0.9 ± 0.2), and 3 (0.5 ± 0.2). Number of large follicles (≥6 mm) increased from FSH (0. 6 ± 0.3) to CRRI (1.4 ± 0.3; P < 0.05), and day 1 (2.3 ± 0.3; P < 0.05), then declined by day 3 (0.6 ± 0.3; P < 0.05). There were more large follicles at CRRI (P < 0.05) with 68 mg (2.1 ± 0.3) or 42 mg (1.6 ± 0.2) than 0 mg (0.5 ± 0.4) FSH. Ovulation rate (mean 2.12 ± 0.05) increased with FSH given 12 h, but not 36 h before CRRI (dosage x time, P < 0.05). Estrous response, conception rate, percentage of ewes lambing or prolificacy did not differ. However, number of corpora lutea not represented by embryos increased with dosage of FSH (P < 0.01; 0.25 ± 0.14, 0.55 ± 0.09, 0.71 ± 0.09 for ewes treated with 0, 42, and 68 mg FSH, respectively).
UR - http://www.scopus.com/inward/record.url?scp=0043241733&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0043241733&partnerID=8YFLogxK
U2 - 10.1016/S0921-4488(03)00111-1
DO - 10.1016/S0921-4488(03)00111-1
M3 - Article
AN - SCOPUS:0043241733
SN - 0921-4488
VL - 50
SP - 1
EP - 9
JO - Small Ruminant Research
JF - Small Ruminant Research
IS - 1-2
ER -