7-Title: Identifying best predictive model for weekly test day milk yield using lactation curve models in Murrah buffaloes

Authors: Sumit Kumar, Vijay Kumar and AK Chakravarty

Source: Ruminant Science (2014)-3(2):163-169

How to cite this manuscript: Kumar Sumit, Kumar Vijay and Chakravarty AK (2014). Identifying best predictive model for weekly test day milk yield using lactation curve models in Murrah buffaloes. Ruminant Science 3(2):163-169.


The adjusted weekly test day milk yields were used to develop three parameters models i.e. Inverse quadratic polynomial function (IQPF), exponential function (EF), mixed log function ( MLF) and the five parameters model polynomial regression function (PRF) by estimating lactation curve parameters for first three and pooled lactations up to second and third parity. Out of four models, the best model was identified for predicting weekly test day milk yield of different lactations on the basis of accuracy of prediction (R2) and the root mean sum of square (RMSE). Among the 3-parameters lactation curve models MLF was found best for predicting weekly test day milk yield (WTDMY) (R2=99.48to 99.73%) in different lactations. The 5-parameters model i.e. PRF was the best model for predicting WTDMY with the predicted error for unadjusted and adjusted WTDMY was 30, 70, 180, 80 gm in first three and pooled lactation. PRF could be used for predicting WTDMY of Murrah buffaloes both in organized herd and under field conditions. The combination of second, fourth & fifth; third, fourth & fifth and second, third & fifth MTDMY were found best for prediction of first, second and third TLMY (R2=60.19, 58.19 and 60.28 per cent) with the corresponding error ranged from 13.71 per cent.


Ali TE and Schaeffer LR (1987). Accounting for covariances among test day milk yields in dairy cows. Canadian Journal of Animal Science 67:637-644.

Batra TR (1986). Comparison of two mathematical models in fitting lactation curves for pure line and cross line dairy cows. Journal of Animal Science 66:405-414.

Catillo G, Macciotta NPP, Carretta A and Cappio-Borlino A (2002). Effect of age and calving season on lactation curves of milk production traits in Italian water buffaloes. Journal of Dairy Science 85:1298-1306.

Guo Z and Swalve HH (1995). Modelling of the lactation curve as a sub-model in the evaluation of test day records. Interbull Bulletin, No. 11.

Jamrozik J, Schaeffer LR and Dekkers JCM (1997). Genetic evaluation of dairy cattle using test day yields and random regression model. Journal of Dairy Science 80(6):1217-1226.

Kumar R and Bhat PN (1979). Lactation curve in Indian buffaloes. Indian Journal of Dairy Science 32(2):156-160.

Nelder JA (1966). Inverse polynomials, a useful group of multifactor response functions. Biometrics 22:128-141.

Olori VE, Brotherstone S, Hill WG and McGuirk BJ (1999). Fit of standard models of the lactation curve to weekly records of milk production of cows in a single herd. Livestock Production Science 58:55-63.

Sherchand L, McNew RW, Kelogg DW and Johnson ZB (1995). Selection of a mathematical model to generate lactation curves using daily milk yields of Holstein cows. Journal of Dairy Science 78:2507-2513.

Wilmink JBM (1987). Adjustment of test day milk, fat and protein yield for age, season and stage of lactation. Livestock Production Science 16:335-348.

Wood PDP (1967). Algebraic model of lactation curve in cattle. Nature 216:164-165.