Agriculture being the backbone of economy contributes 21% of GDP in which major share 55.5 % is of Livestock sectorin the agriculture value added and 11.9 percent of National GDP.Total milk production in Pakistan is 52 million tons per year. Buffalo is playing a leading role in the national economy by producing more milk.Out of total milk produced in the country, buffalo contributes about 68%(Anonymous,2012). Nili Ravi is the best performing animal producing more milk than other buffalo breeds in the world (2500 liters per lactation) but daily average milk production per animal is 7-8 liters. Increasing population in the World as well as Pakistan has resulted in higher demand of milk and milk by products. Animalresearchers are trying to devise different ways through which they can fulfill the increasing demand of milk and meat. Milk and meat production enhancement through different biotechnologies are thought to be important for the developing countries. Synthetic Bovine Somatotropin Hormone (bST) is one of biotechnological product which can help to increasethe production of animals.
The current study was conducted atLivestock Experiment Station Bhunikey, Pattoki to determine the effect ofbSTon DMI, body weight, milk production, milk composition, body condition score and production efficiencyin lactatingNili-Ravi buffaloes.Fifty Nili-Ravi lactating buffaloes were selected from the herd at LES Bhunikey, Pattoki. The buffaloes were randomly divided into two groups (A and B) with 25 in each group.All the buffaloes offered silage ad libitum, water access round the clock and supplemented with concentrate @ 1 kg for 2 liter of milk production. Group A was administered with 500mg bST at 14 days interval for 5 months and group B was as control.
Dry matter intake was recorded on weekly basis and milk production measured twice a day (morning and evening). Body weight of buffaloes measured on monthly basis. Milk samples were collected after every 2 weeks for fat, lactose, proteins, solid-not-fats and total solids contents using milk analyzer in the Farm and Health Laboratory, Buffalo Research Institute, Pattoki. Body condition score of buffaloes on 5-point scale recorded before bST administration during adjustment period then during bST treatment in middle of experiment and finally when withdraw of bST administration.
Data obtained was statistically analyzed through analysis of variance (ANOVA) using proc GLM procedure of SAS. Treatment was considered as fixed effect and start milk was used as covariate to avoid any bias.
Milk production, DMI and mastitis incidence significantly increased in lactating Nili-Ravi buffaloes with bST administration. Body condition score decreased significantly but body weight change was non significant in bST treated buffaloes.
bST treatment increased milk production in lactating Nili Ravi buffaloes.However, the mastitis incidence and antibiotic treatment increased in bST treated animals. Antibiotic residues in milk are major cause of antibiotic resistance in humans which is a huge challenge to humanity in 21st century. So bST treatment is not a viable approach for enhancing milk production.