Dr. R.S. PandeySonam Tasering Bhutai2024-05-212024-05-211985https://krishikosh.egranth.ac.in/handle/1/5810209326On the basis of salient striking findings of this study, following conclusions could be drawn. 1. 3/4 to 1/2 HP groups behaved almost similarly for various economic traits which suggested that probably 1/2 exotic inheritance or slightly more than 1/2 was best suited for Indian conditions. 2. Significant effect of period suggested that manage mental conditions of the farm in recent year have slightly improved over the past. 3. It appeared in this study that animals did not attain full biological growth and production potential unless reached in 3rd lactation. This give guide lines to the breeders that on the basis of first and second lactation only, there is considerable risk involved in culling the animals. 4. Prediction of 300 days yield on the basis of first 30 days itself gave almost maximum accuracy in all the genetic groups which is economical too. 5. No generalized criteria could be applied to select animals of different genetic groups on the basis of their part lactation yield. Animals having high exotic inheritance (3/4) and low (3/8 HF) are probably required to be selected on the basis of 90 days part lactation yield where as, those having 1/2 and 5/8 HF level could be quite accurately selected on the basis of their 60 days records itself.EnglishThesis