Prediction of Fortnightly Test-Day Milk Yields Using Four Different Lactation Curve Models in Indian Murrah Buffalo.

Saroj Kumar Sahoo

doi:10.14737/journal.aavs/2014/2.12.647.651

Abstract

The present investigation was carried out using data on 18871 fortnightly test day milk yield (FTDMY) records during first lactation of 961 Murrah buffaloes calved during 1977-2012 maintained in an organized farm at National Dairy Research Institute, Karnal. The least squares means of the FTDMY ranged from 2.35kg to 7.92kg. The relative efficiency of four lactation curve models via. Gamma-type function (GF), Exponential function (EF), Mixed log function (MLF) and polynomial regression function (PRF) were compared. PRF described the highest coefficient of determination (R2) (99.78%) and with least value (0.02kg) of root mean squares error (RMSE), whereas, least coefficient of determination (93.13%) was observed in Gamma-type function having maximum (0.1kg) RMSE value suggesting PRF being best mathematical model for prediction of FTDMYs in Murrah buffaloes.

Highlights

MATERIALS AND METHODSLactation curve is the graphical representation of milk yield against time (Brody et al, 1923)
The least squares means of the fortnightly test day milk yield (FTDMY) were calculated for adjustment of effect of non-genetic factors
In accordance with the present findings, Chakraborty et al (2010) observed the minimum least-squares means as 4.43 ± 0.09 kg on monthly test day1 (MTD 1) (6th day) and maximum as 8.11 ± 0.25 kg on MTD 3 (65th day) in Murrah buffaloes

Summary

Introduction

MATERIALS AND METHODSLactation curve is the graphical representation of milk yield against time (Brody et al, 1923). Keywords | FTDMYs, Lactation curve, Gamma-type function, Exponential function, Mixed log function, Polynomial regression function, Murrah Prediction of fortnightly test-day milk yields using four different lactation curve models in Indian Murrah Buffalo..

Results

Conclusion