Growth and survivability of GH/Msp I genotypes in malabari goats

Abstract

etc. Growth hormone gene, due to its essential role in lactation and growth processes, is a perfect candidate marker associated with somatotropic axis. Selection of animals based on the growth hormone genotypes can be introduced in the animal husbandry sector for better production. The present investigation was undertaken to study the growth and survivability of GH/MspI genotypes in Malabari goats at different centers of Badagara, Thalassery, Thanur as well as Malabari conservation unit, Regional Agricultural Research Station, Pilicode. DNA was isolated from 32 bucks, 241 does mated to those bucks and 297 of their progeny using phenol - chloroform extraction method. A 768-bp fragment from third exon to fifth exon containing the polymorphic Msp1 site was amplified well using bovine primers, indicating species homology. The amplified product on digestion with the Msp1 enzyme revealed the GH/Msp1 (+) and (-) alleles. The percentage of incidence of (+/-) genotype was 61.76 and that of (+/+) genotype was 38.24. None of the animals typed were of the GH/Msp1 (-/-) genotype. The genotype frequencies of bucks and does were consistent with the general population. In the specific heterozygous mating (+/- x +/-), 28 per cent of the progenies were (+/+) homozygotes and the rest 72 per cent were heterozygotes (+/-). Early embryonic mortality was not found to be a cause for the absence of the GH/Msp1 -/- genotype as the kidding percentage in heterozygous mating were not different from other types of matings. There was no relationship between growth upto six months of age and GH/Msp1 genotypes. The study confirms a strong heterozygotic advantage for the GH/Msp1 +/- genotype and also the absence of GH/Msp1 -/- genotype in Malabari goats. Presence of duplicate copies of the growth hormone gene in goats may be a possible reason for the above results.