FACTORS AFFECTING ON AGE AT FIRST CALVING IN CROSSBRED CATTLE MAINTAINED AT LES QADIRABAD DISTRICT SAHIWAL

Abstract

The data on age at first calving for 539 records of crossbred cows of different
filial/genetic groups were considered for the present investigation. These crossbreds belonged to eight
filial/genetic groups (F1, F2, F3, F4, F5, F6, F7 and F8) maintained at Livestock Experiment Station
Qadirabad District Sahiwal from 1991 to 2014 (24 years). The duration of 24 year was divided into 6
periods (P1, P2, P3, P4, P5 and P6) of four years each. Each year was further divided into three
seasons as winter (November-February), summer (March- June) and spring (July-October) on the basis
of geo-climatic conditions prevailing in the region. The overall population mean of age at first calving
was determined 1261.88±9.934 days. The analysis of variance revealed significant effect of period of
calving on age at first calving. The finding of this study shows that age at first calving was subjected to
non-genetic factor. Effect of season of calving on age at first calving was non- significant which
indicate breed characteristic to adaptation with environment. Meanwhile effect of filial/genetic group
was significant on age at first calving. Therefore, from the result of this investigation it can be
determined that improving the feeding, health and other husbandry practices are essential to enhance
the performance trait of this herd.