Abstract:
A study was conducted in district Bannu located in the southern dry piedmont mountains of the NWF Province of Pakistan. Records of 300 crossbred cows, produced through use of Holstein Friesian semen in native, non-discript cows, were studies. Data on various productive and reproductive parameters were analyzed. The average age at puberty was 752±10.9 days, ranging from 420 to 1620 days and was positively correlated with mounting (r = 014) and negatively with estrus duration, vaginal mucus and calving interval (r = -0.14, -0.13, -0.15, respectively; P<0.05). the average inter-estrus interval was 20.0-19.07 days, ranging from 15 to 24 days. Estrus duration was 34.0±0.85 hours, ranging from 17 to 72 hours and was positively correlated with vaginal mucus (r = 0.12) and services per conception (r = 0.14) and negative with bellowing ( r = 0.11), P< 0.05). number of services per conception in the crossbred cows averaged 1.6±0.1„ ranging from I to 12 and was correlated positively, with daily milk yield and negatively with lactation length and vaginal mucus (r = 0.32. —0.31, -0.27 respectively, P< 0.01). calving interval was 612±4.56 days, ranging from 360 to 900 days and was negatively correlated with age at puberty, daily milk yiekd and use of oxytocin (r = -0.15. —0.67, -0.62, respectively, P < 0.0)). The average lactation length of the cows was 503±6.36 days, ranging from 30 to 1441 days. The mean daily milk yield was 10.1±0.14 Kg, ranging from 1.0 to 18.0 Kg. The standard deviation (SD) for average daily milk yield was 2.36 Kg. Number of animals 1 SD above mean was 28.0% and those 2 SD above mean was 17.0%. number of animals 1 SD below mean was 51.4% and those 2SD below mean was 3.6%. the wide variation makes a good base for productivity enhancement through selective breeding. It may be concluded that productive and reproductive performance is satisfactory in crossbred cattle under field conditions showing their adaptability to the local environment.
