Dairy sector commercialization is growing in Pakistan. The import of Holstein cows has been dramatically increased from last decade. Calf mortality is the major constraint in the field of livestock. Calves are considered as the future of dairy farm and mainly responsible for the replacement of stock. Certain diseases cause calf mortality among which bacterial infections carry prime importance.Supplementation of probiotics in milk will reduce the occurrence of diarrhea and increase the body weight, growth rate and average daily gain in Holstein Friesian calves.Holstein Friesian calves (n=60) will be taken from their dams at six days of age and all calves on the basis of initial weight and sex will be selected for the trial. There will be (n=40) calves in the probiotic group and (n=20) calves in the control group.Each group will be further sub-divided into two sub-groups i.e. (n=20) in Group B and (n=25) in Group C. The initial average weight of the calves will be determinedin the two groups. The health status of the calves will be monitored daily with particular attention paid to the occurrence of diarrhea. The actual trial period will start at weaning (day 0) when the calves will be six days old and will be stopped 56 days later. All calves in probiotic group will be offered milk containing probiotic (Calf PRE RD, TechMix, LLCTM, USA) at the dose rate of 4gm per calf per day. The health status, body weight, average daily weight gain and occurrence of diarrhea will be monitored on daily basis. All calves will be given a diarrhea score according to the following scale: 0 = firm, no signs of diarrhea, 1 = soft, slightly loose feacal consistency and 2 = liquid, very loose feacal consistency(Jatkauskas et al., 2010). For each calf the daily scores and the number of days with liquid feaces (score 2) will be summed into an index of the severity of the diarrhea.
Data on occurrence of diarrhea will be compared among groups by using Chi-square (χ2) test whereas data on growth rate, body weight and average daily gain will be measured using t-test. All data will be analyzed using SPSS (statistical package for social sciences),P< 0.05 will be considered significant.
The current study will help in reducing the occurrence of diarrheain Holstein Friesian calves. Further, it will also assist in finding out the efficacy of probiotics supplementation in reducing the incidence of calf mortality.