Characteristics, Curve and Persistency of Lactation in Gir Cows
Pravin N. Chaudhari Pratik S. Kapadiya Mahesh R. Gadariya Pranav M. Gamit Bhagavanji D. Savaliya
Vol 12(1), 12-18
Lactation milk yield in dairy bovines is closely related with peak yield, persistency and lactation length. Therefore, characteristics, curve and persistency of lactation were studied in Gir cows. A total of 2,24,748 morning and evening milk production records of 300 lactations of 1-6 parity Gir cows present at Cattle Breeding Farm, JAU, Junagadh, Gujarat over a period of 31 years (1986-2016) were used for this study. Overall lactation length (LL), total lactation milk yield (TLMY) and standard lactation milk yield (SLMY) of the Gir cows averaged 371.59±5.42 days, 2674.21±48.79 lit and 2380.79±37.68 lit, respectively. Overall daily peak yield (DPY) was 13.25±0.17 lit/day, attained at 48.47±2.40 days postpartum. Overall weekly peak yield (WPY) and weeks to attain WPY averaged 82.08±1.11 lit/week and 6.54±0.31 weeks, respectively. Weekly milk yield could be predicted using linear function [(y ̂=79.5139+(-1.1002×X)] and logarithmic function [(y ̂=1.9378× (-0.00965) ^X)] with an accuracy of 86 to 95%, while monthly milk yield could be predicted using linear function [(y ̂=348.52+(-20.26×X)] and logarithmic function [(y ̂=2.588× (-0.042) ^X)] with comparatively higher R2 value of 94.01 to 98.05%. Overall persistency, in terms of weekly and monthly milk yield was estimated to be 96.82±0.13% and 88.77±0.37%, respectively.
Keywords : Gir Cows Lactation Characteristics Lactation Curve Linear Regression Peak Yield Persistency
Read : 1226
Downloads : 258