Impact of environmental factors on milk constituents and yield traits in Murrah buffaloes

Abstract

The present study was carried out to analyse milk constituents and yield traits using 1,582 first lactation monthly test day records of 224 Murrah buffaloes, calved between 2006 and 2014. The overall least-squares means of monthly test day milk constituent traits, viz. fat, protein, lactose, solids-not-fat (SNF) and total solids (TS) were 7.96 ±0.07, 3.86±0.02, 5.63±0.02, 9.97±0.01 and 17.75±0.07%, respectively. The overall least-squares means ofmonthly test day milk constituent yield traits, viz. milk yield, fat yield, protein yield, lactose yield, SNF yield and TS yield were 6.95±0.15 kg, 549.76±12.97 g, 269.17±6.12 g, 392.52±8.65 g, 681.02±14.97 g and 1231.00±27.46 g, respectively. The estimates of milk constituent traits were found higher in autumn and lower in summer season, except SNF (%) that was found higher in rainy season. All the yield traits were found higher in winter and autumnseason and lower in rainy season. Milk protein (%) was significantly higher during early stage (<90 days) and decreased along with stage of lactation. On the other hand, milk lactose (%) was minimum during early stage of lactation and increased thereafter. All the yield traits were significantly higher during early stage and decreased with the stage of lactation. All the milk constituent traits were higher in buffaloes calved up to the age of 51 months; whereas, buffaloes calved after 51 months of age had higher yield traits. Phenotypic correlations revealed that, milk fat, lactose and TS per cent had very low and negative correlation with monthly test day milk yield. The milk fat (%) had very high and positive correlation with TS (%), indicating that, buffaloes with higher fat content may be selected for higher TS content in milk. Data on variation of milk constituent and yield traits over the years, seasons, stages of lactation and age of buffaloes can be utilized to improve quality as well as quantity of milk in breed improvement programmes.