Some reproductive characteristics of prolific Targhee breed and crossbred ewes
No hay miniatura disponible
Fecha
Autores
Título de la revista
ISSN de la revista
Título del volumen
Editor
Universidad de Colima
Resumen
Descripción
A total of 225 ewes from seven genotypes were endoscopically examined 7-8 days after breeding to determine ovulation rate, lambing rate, litter size and embryonic survival. More single and unilateral twin ovulations were observed from the right (P<0.01) ovary. Double ovulations (71.1%) occurred more frequently (P<0.01) than singles (15.5%) or triples (13.3%). The number of bilateral and unilateral double ovulations was similar (P>0.05). No difference was found in embryo survival (P>0.01) among singles, doubles and triples (69.8%, 76.0% and 63.0% respectively) or between unilateral and bilateral ovulations. Twin selected Targhee line (TW) produced the highest litter size (mean = 2.0±1.4) while the general Targhee flock produced the lowest. The ½ Targhee, ¼ Barbados, ¼ Dorset line had the highest general lambing rate (94%), followed by the Polypay (87%) (P>0.05). It was concluded that the right side ovary was the most active one, that among the genotypes studied, double ovulations were more common than single or triple, and that the twin selected Targhee breed had the highest mean litter size when compared with the general flock Targhee or their crosses.
Palabras clave
Agrociencias