Go to Top Go to Bottom
Animal Breeding and Genetics
Asian-Australasian Journal of Animal Sciences 2003;16(5): 639-643.
DOI: https://doi.org/10.5713/ajas.2003.639    Published online January 1, 2003.
Genetic Evaluation of First Lactation Traits in Sahiwal Cattle Using Restricted Maximum Likelihood Technique
V. Choudhary, M. D. Kothekar, K. L. Raheja, N. N. Kasturiwale, D. W. Khire, P. Kumar
Abstract
The data on 283 Sahiwal cows, sired by 16 bulls, maintained at Cattle Breeding Farm of Nagpur Veterinary College and Dairy Farm of Agricultural College, Nagpur, were considered for the estimation of genetic parameters. Variance and covariance estimates of first lactation traits were obtained using restricted maximum likelihood technique (REML). When first lactation milk yield (FLMY), first lactation length (FLL) and average daily yield (ADY) traits were considered for REML analysis, the heritabilities were 0.184 0.146, 0.132 0.131 and 0.141 0.133, respectively. While, genetic and phenotypic correlations between them were medium to high except phenotypic correlations between FLL and ADY (-0.025). REML procedure considering FLMY, age at first calving (AFC) and first service period (FSP) combination exhibits heritabilities as 0.274 0.173, 0.506 0.233 and 0.274 0.172, respectively. Genetic correlations were -0.120 0.376, 0.225 0.423 and 0.365 0.331 between FLMY and AFC, FLMY and FSP, AFC and FSP, respectively. Phenotypic correlations were 0.057, 0.289 and 0.123, respectively. Considering all five traits REML combination heritabilities estimated were 0.238 0.162, 0.160 0.139, 0.136 0.132, 0.409 0.209 and 0.259 0.168 for FLMY, FLL, ADY, AFC and FSP, respectively. The genetic correlations were positive except FLMY and AFC. The phenotypic correlations were also positive except FLL and ADY, ADY and FSP. Almost all estimates were associated with high standard error.
Keywords: REML; Convergence; Iteration; Canonical Transformation; Sahiwal Breed


Editorial Office
Asian-Australasian Association of Animal Production Societies(AAAP)
Room 708 Sammo Sporex, 23, Sillim-ro 59-gil, Gwanak-gu, Seoul 08776, Korea   
TEL : +82-2-888-6558    FAX : +82-2-888-6559   
E-mail : jongkha@hotmail.com               

Copyright © 2020 by Asian-Australasian Journal of Animal Sciences. All rights reserved.

Close layer
prev next