Vol. 11, Special Issue 6 (2022)

Author(s):
Pravin N Chaudhari, Mahesh R Gadariya, Bhagavanji D Savaliya and Pratik S Kapadiya

Abstract:
Standard lactation milk yield (SLMY) was predicted by simple regression equation from weekly, fortnightly and monthly, individual and cumulative part yields in Gir cows. A total of 300 normal lactations of Gir cows from 1^st to 6^th parity with lactation length >210 days were utilized. Correlation coefficients between 305-day milk yield (SLMY) and different weekly (1^st to 25^th week), fortnightly (1^st to 10^th fortnight) and monthly (1^st to 5^th month), individual and cumulative part lactations were positive and significant (P<0.01) and showed increasing trend with advancement of lactation. Reliability of prediction for standard lactation milk yield (SLMY) was reasonably high, i.e., about 85% with 20^th, 21^st, 22^nd or 24^th week yield, 9^th or 10^th fortnight yield and 5^th month part lactation yields. Individual part yields were found to be more reliable than cumulative respective (weekly, fortnightly and monthly) part yields for prediction of SLMY. WY14 or FNY7 milk yield as part lactation covered 78.18-79.85% of variation in SLMY in of Gir cows. R² value of 72.26% for first 100-day milk yield as part lactation was quite reliable to determine production potential in terms of SLMY of Gir cows. However, considering 4^th or 5^th month (120 to 150-days) milk yield alone of the cows gave still higher reliability (R², 82.27 to 87.40%) of SLMY.