- Email: [email protected]
Description and analysis of factors influencing the response of 449 superovulated donor cows and heifers
rHERIOGENOLOGY
DESCRIPTION AND ANALYSIS OF FACTORS INFLUENCING THE RESPONSE OF 449 SUPEROVULATED DONOR COWS AND HEIFERS P. Holm (I), and P. Willeberg (2). T. Greve (l), (I) Dept. of Animal Reproduction, (2) Dept. of Forensic & State Vet. Med., Royal Veterinary & Agricultural University, Copenhagen, DK-1870 Frederiksberg C. Denmark. The objective of this study was to retrospectively evaluate data from superovulation of 449 Danish donor cows and heifers in order to elucidate some factors affecting the donor response, to follow up earlier Danish studies concerning this matter (Greve 1981). Data have been collected since 1979 in relation to ET carried out Donors were at private farms (PF, n=264) or ET-centres (ETC, n=185). injected with 2000-3000 u PMSC (Antex R, Leo) once (n=424) or with 28-38 mg FSH-P (Burns Biotec) administered over 4-4; days with twicedaily injections in decreasing doses (n=25), both treatments beginning between days 8 and 12 (estrus=day 0). PG (Estrumat@, Dinolyt$ , 48-72 hours after the initiation of or ProsolvinR ) was injected treatment. Donors were inseminated once or twice in the following heat, and Requirements of the donors enterflushed 6-8 days later, ing the ET-programme, flushing procedure and the evaluation of the response followed principles published by Q-eve (I 981). The followmg factors formed the categoric independent parametres: location (ETC, PF), breed (Holsteins, Red Danish, Jersey, Beef-cattle), lactation (heifers, 1, 2-3, 4-6 ),7), days from calving (DFC= 60, 61-90,91-180, o+lZl), post partum period [PPP=normal, or abnormal (detained afterbirth/metabolic disease)], season (2-month intervals), hormone (PMSC,FSH) and PMSG-dose (2000-2250 u,2500 U, 2800-3000 u). The response was measured by the dependent variables: 1) ovarian stimulation ( OVS=non, normal or excessive), 2) flushed/notflushed, 3) viable embryos (VE), as a) mean value XvE or b) proportion of donors resulting ins4VE (PRT4VE) and the ‘relative risk’ for this event (RR b 4VE). Restriction and stratification of data, along with Mantel-Haenszel procedures were performed to control confounding. The crude-results of treated donors showed that: I) 9%, 62% and 28% had non, normal and excessive OVS respectively, 2) 12% were not flushed 3a) XVE was 2.8 r 0.2 VE and 3b) PRa4VE was 30% and these donors delivered 80% of the total number of VE. Analysis of the independent parametres showed that those listed in the table had a significant (P9/2.9 2.413.4 1.3J3.0 (a/b) XVE RR 4VE (a/b) 0.63/l 0.6411 0.701 I 1.54/l 0.521 I The other independent parametres did not significantly influence VE, but Jersey as well as the donor-category ‘2800-3000 u. PMSG’ gave significantly higher proportion of donors with excessive OVS (49% & 43%, respectively) than the other categories of the respective parametres. Ref: ‘I. Greve, Bovine Egg Transplantation in Denmark, Thesis, Carl F. Mortensen A/S,Copenhagen, 1981.
238
JANUARY
1987 VOL. 27 NO. 1
DESCRIPTION AND ANALYSIS OF FACTORS INFLUENCING THE RESPONSE OF 449 SUPEROVULATED DONOR COWS AND HEIFERS P. Holm (I), and P. Willeberg (2). T. Greve (l), (I) Dept. of Animal Reproduction, (2) Dept. of Forensic & State Vet. Med., Royal Veterinary & Agricultural University, Copenhagen, DK-1870 Frederiksberg C. Denmark. The objective of this study was to retrospectively evaluate data from superovulation of 449 Danish donor cows and heifers in order to elucidate some factors affecting the donor response, to follow up earlier Danish studies concerning this matter (Greve 1981). Data have been collected since 1979 in relation to ET carried out Donors were at private farms (PF, n=264) or ET-centres (ETC, n=185). injected with 2000-3000 u PMSC (Antex R, Leo) once (n=424) or with 28-38 mg FSH-P (Burns Biotec) administered over 4-4; days with twicedaily injections in decreasing doses (n=25), both treatments beginning between days 8 and 12 (estrus=day 0). PG (Estrumat@, Dinolyt$ , 48-72 hours after the initiation of or ProsolvinR ) was injected treatment. Donors were inseminated once or twice in the following heat, and Requirements of the donors enterflushed 6-8 days later, ing the ET-programme, flushing procedure and the evaluation of the response followed principles published by Q-eve (I 981). The followmg factors formed the categoric independent parametres: location (ETC, PF), breed (Holsteins, Red Danish, Jersey, Beef-cattle), lactation (heifers, 1, 2-3, 4-6 ),7), days from calving (DFC= 60, 61-90,91-180, o+lZl), post partum period [PPP=normal, or abnormal (detained afterbirth/metabolic disease)], season (2-month intervals), hormone (PMSC,FSH) and PMSG-dose (2000-2250 u,2500 U, 2800-3000 u). The response was measured by the dependent variables: 1) ovarian stimulation ( OVS=non, normal or excessive), 2) flushed/notflushed, 3) viable embryos (VE), as a) mean value XvE or b) proportion of donors resulting ins4VE (PRT4VE) and the ‘relative risk’ for this event (RR b 4VE). Restriction and stratification of data, along with Mantel-Haenszel procedures were performed to control confounding. The crude-results of treated donors showed that: I) 9%, 62% and 28% had non, normal and excessive OVS respectively, 2) 12% were not flushed 3a) XVE was 2.8 r 0.2 VE and 3b) PRa4VE was 30% and these donors delivered 80% of the total number of VE. Analysis of the independent parametres showed that those listed in the table had a significant (P
238
JANUARY
1987 VOL. 27 NO. 1