Environmental factors affecting productive traits and their trends in Nili-Ravi buffaloes

The objective of the study was to determine the environmental factors affecting the productive traits of nili-ravi buffalo. data on 9003 lactation records kept at four government livestock farms in punjab province of pakistan were used to study the effect of environmental factors on productive traits of nili-ravi buffaloes. the productive traits were analyzed by the model included herd-year,season of calving and within parity age classes along with lactation length as covariate. average total milk yield,lactation length and dry period were 1840±08 kg,278±1 days and 258±2 days,respectively. the herd-year of calving,season of calving (birth) and parity significantly affected milk yield,lactation length and dry period (p<0.05). overall phenotypic trend in milk yield during 1971-2000 was slightly negative (-0.7 liter per year) but there was a wide variation (-25 to 9 liter) among herds and dry period increased by 0.5 days per year,respectively. phenotypic trend of lactation length was observed same during this period. productive traits under study affected by herd,year of calving,season of calving and parity. appropriate data recording is utmost needed for the productive traits i.e. milk yield,lactation length and dry period in order to improve productivity of buffaloes in future.