6-Title: Prediction of first lactation 305-day milk yield by test day regression models in Murrah buffaloes
Authors: SK Sahoo, Avtar Singh and GS Ambhore
Source: Ruminant Science (2021)-10(1):29-32.
How to cite this manuscript: Sahoo SK, Singh Avtar and Ambhore GS (2021). Prediction of first lactation 305-day milk yield by test day regression models in Murrah buffaloes. Ruminant Science 10(1):29-32.
The present study was conducted to determine the most important weekly test days from different segments of the lactation curve for the prediction of the first lactation 305-day milk yield in Murrah buffaloes. Data was collected on first lactation 39059 weekly test-day milk yield records of 961 Murrah buffaloes sired by 101 bulls during 1977-2012 (36 years) maintained at Livestock Farm, ICAR-National Dairy Research Institute, Karnal. The best single, two, three and four test day combinations were selected for the prediction of FL305DMY based on adjusted R2 and RMSE values. The accuracy of prediction of 305-day milk yield from weekly test day milk yields was observed to be best for TD-7 (48th day) and TD-22 (153rd day) (Adjusted R2=86%) as in three best test day combinations (TD-7 + TD-22 + TD-34) for 2% more accuracy we have to wait for 12 more weeks (84 days). It was concluded that the FL305DMY can be predicted as early as the 153rd day of lactation. The equation Y=42.37 + 92.94*TD7 + 168.29*TD22 was identified as best for predicting the 305-day milk yield based on weekly test day milk (early test days were selected without compromising much on accuracy). It was concluded that the equation comprising of 48th and 153rd day of lactation for prediction of FL305DMY can aid in making culling decisions and be used for early genetic evaluation of Murrah sires based o n progeny performances.
Appannavar MM, Kumar S and Shashidaran T (1995). Test day models in predicting 305 days first lactation milk yield in Surti buffaloes. Indian Journal of Dairy Science 48:411-12.
Bilal G and Khan MS (2009). Use of test-day milk yield for genetic evaluation in dairy cattle: A review. Pakistan Veterinary Journal 29(1):35-41.
Chaudhari JD, Gupta JP, Pandey DP, Parmar GA, Prajapati BM, Prajaparti MN and Patel PA (2018). Comparative evaluation of Mehsana buffalo bulls by simple daughter and contemporary comparison methods using first lactation milk yield. Ruminant Science 7(1):51-54.
Dass G and Sadana DK (1999). Predictability of lactation milk yield based on test day values in Murrah buffaloes. Indian Journal of Animal Research 37(2):136-138.
Kumar Sumit, Goel R, Sharma Deepak and Tiwari Madhu (2013). First lactation performance of Sahiwal in the region of northern India. Ruminant Science 2(1):77-79.
Kumar Sumit, Kumar Vijay and Chakravarty AK (2014a). Identifying best predictive model for weekly test day milk yield using lactation curve models in murrah buffaloes. Ruminant Science 3(2):163-169.
Kumar Sumit, Kumar Vijay and Chakravarty AK (2014b). Effect of non-genetic factors on first lactation test day milk yield in murrah buffaloes. Ruminant Science 3(1):99-103.
Patil CS, Chakravarty AK, Kumar V, Sharma RK and Kumar P (2012). Average performance of various first lactation 305 day and test day milk yield in Murrah buffaloes. Indian Journal of Animal Research 46(3):310-312.
Rana E, Gupta AK, Singh A, Ruhil AP, Malhotra R, Yousuf S and Ete G (2020). Prediction of first lactation 305-day milk yield based on bimonthly test tay milk yield records in Murrah buffaloes. Indian Journal of Animal Research DOI: 10.18805/ijar.B-3963.
Sharma N, Narang R, Ratwan P, Kashyap N, Kumari S, Kaur S and Raina V (2019). Prediction of first lactation 305-days lactation milk yield from peak yield and test day milk yields in crossbred cattle. Indian Journal of Animal Sciences 89(2):200-203.
Singh A and Rana JS (2008). Prediction of 305-day milk yield based on test-day values in Murrah buffaloes. Indian Journal of Animal Science 78(10):1131-1133.
Singh PK, Kumar Sumit, Goel R and Singh SP (2013). Genetic studies on some production traits in Sahiwal cows. Ruminant Science 2(2):201-203.
Singh S, Tailor SP, Mishra S, Kothari MS and Garg MK (2013). Prediction of first lactation 305-day milk yield using monthly part and test day yields in Surti buffaloes. Indian Journal of Animal Science 83(11):1219-1220.
Swalve HH (2000). Theoretical basis and computational methods for different test-day genetic evaluation methods. Journal of Dairy Science 83:1115-1124.