[Use of culled cows as embryo donors].
In a trial, 134 donors (cows and first-calvers) culled for slaughter owing to a low performance, udder disease, infertility and other reasons (termination of productive age, foot disease, etc.) were treated with 2000 to 4000 i. u. PMSG (Serum gonadotropin, Bioveta) to induce superovulation. The embryos were obtained post mortem on the sixth to ninth day after the first insemination. Among the donors culled for infertility the proportion of superovulated animals was 53.1% and among those culled for "the other" reasons this proportion was only 46.2%; out of the cows eliminated for a low performance and udder diseases 76.3% and 70.6% were superovulated. The highest stimulation was obtained in cows culled for "the other" reasons (14.58 CL) and for infertility (12.41 CL). The level of embryo gain was good in donors culled for a low performance (57.3% of CL number, 6.82 eggs), for "the other" reasons (59.3%, 8.64 eggs) and for udder diseases (62.6%, 6.83 eggs), it was the lowest in infertile donors (46%; 5.71 eggs-P-insignificant). These donors had the largest proportion of embryos suitable for transfer--66.9% out of the eggs obtained. A good proportion of suitable embryos was also found in donors culled for a low performance (61.7%) and for "the other" reasons (55.8%); the lowest proportion of suitable embryos was obtained in the donors with diseased udders (48.8%). Good proportions of superovulated donors (from 53.5% to 85.7%) and acceptable results of stimulation were kept for about a year after calving.(ABSTRACT TRUNCATED AT 250 WORDS)
D000818:Animals; D002417:Cattle / Q000502:physiology*; D004624:Embryo Transfer / Q000662:veterinary*; D005260:Female; D011247:Pregnancy; D013480:Superovulation / Q000187:drug effects
Vyuzití vyrazených krav jako dárců embryí.