Resumen de Efecto de diversos factores de explotación sobre el intervalo entre partos de vacas Moruchas y Morucha x Charolés
S. Alvarez, Carlos Palacios Riocerezo
456 calving intervals of 189 cows have been analyzed in order to know the effect of age, genetics (Morucha vs. Morucha x Charolais), year and farm on fertility. Mean interval is 393.55 (+ 5.99) days, similar to other Spanish breeds which are also kept in extensive systems. No effect of genetics or farm has been found. Age causes longer calving interval when cows are 12 or more year-old (421.35 + 12.18), but there was no effect on first calving interval (382.78 + 9.94) days vs. 376.52 + 4.90 in cows aged 5-11 years), perhaps because first service is very late (at the age of 20-28 months) or supplementary feeding is correct. First year has shown significant differences, whereas the other two years have not differences.
