Factors affecting milk fat percent of Nili-Ravi buffaloes in Pakistan.

Monthly fat tests for 895 lactations of Nili-Ravi buffaloes in a Livestock Production Research Institute herd were used to estimate environmental effects on fat percentage. Fat tests rose progressively from 1st to 10th mo of lactation (5.51 to 7.46%). Average lactation fat percent was 6.55 +/- .06. Year effects were significant, but season, age, parity, milk yield, and health status were not. Percent fat increased slightly to maturity (6.54 first parity; 6.65 fifth). Lactations initiated April to September averaged slightly higher (6.60%) than other months (6.50%). There was a slight, although real, decrease in fat percent with increased lactation milk yield (6.60, 6.63, 6.60, 6.43, 6.51 for 1000 to 1500, 1501 to 2000, 2001 to 2500, 2501 to 3000, and greater than 3,000 kg). Effect of treatment for health problems was small (6.51 treated versus 6.59% untreated). Of all fat tests (7,772) 60% were 5.1 to 7.0%, 27% were between 7 and 9%, but only 3% exceeded 9%. Lactation fat percent averaged 1.0 less than most percents for buffaloes because of system of milking and milk yield (2,130 kg). Fat percentage of buffaloes appears to be influenced by environmental factors in the same proportion as for cattle, but buffaloes would be expected to exceed cattle in fat percent by 1 to 3% depending on breed and environmental conditions.