Sunny, K LRema, T PKAU2020-02-052020-02-051985http://krishikosh.egranth.ac.in/handle/1/5810142529PGRecords on birth weight, age at first kidding, body weight at first kidding and first lactation milk yield of Malabari, Sannon % tnalabari (SM) , Alpine X Malabari (AM) and AM X AM (F2 A) goats from 1974- 1984 were examined to make a comparative study of selection indices constructed by employing different methods. The relative economic value of each trait in rupees was calculated as 29,96 for birth weight, 0.67 for age at first kidding, 20.83 for body weight at first kidding and 18 for first lactation milk yield. Simultaneous selection indices wore constructed by incorporating all tho traits together for each breed and on finding the percent gain in efficiency of each index over that due to straight selection, the efficiency of index selection was proved. Out of the seven restricted selection indices constructed for each breed, imposing restriction on birth weight was found effective for Malabari, SM and F2A breeds and restriction on body weight at first kidding was effective for both f 2 a and AM breeds. But all these effective restricted selection indices, except the one for Malabari breed (when birth weight was restricted) were increasing the age at first kidding. Seven phenotypic selection indices were constructed for each breed. But none of them was found improving the first lactation milk yield of Kalahari and F2A goats. For SM breed, the best index was the one constructed between the main trait first lactation milk yield and the auxiliary trait age at first kidding. Relative efficiency was the largest, when all the auxiliary traits were considered simultaneously for improving the first lactation milk yield of AM goats.ennullThesis