KARYOTYPE OF CROSSBRED PROGENY BORN TO THE INTERSPECIES HYBRIDIZATION OF WILD AND ZEBU CATTLE WITH REFERENCE TO THEIR FERTILITY AND GROWTH PERFORMANCE

Abstract

Karyotypes of the crossbred progeny of wild and zebu cattle, born from the insemination of zebu dams with deep frozen semen from gaur (Bos gaurus) and banteng (Bos javanicus) sires were studied. The crossbred progeny (F1) born from the gaur sire and zebu dams revealed a diploid chromosome number of 2n=58. Fifty-four acrocentric and 2 submetacentric autosomes were found, sex chromosomes being submetacentric and metacentric in the male and submetacentric in the female. Two types of chromosomes with a complement of 2n=59 and 2n=58, were found in the crossbred progeny (F1) of the banteng sire and zebu dams. Robertsonian translocation of 1, 29 was found in crossbred progeny with 2n=59 whereas 1/29 and 2/27 Robertsonian translocation was found in those with 2n=58. Sex chromosomes in both groups were the same as those of the crossbred progeny (F1) of the gaur sire and zebu dams. Female crossbred progeny (F1) born to both gaur and banteng sires can conceive after natural breeding, males however could not produce sperm. The growth performance of these crossbred progeny was satisfactory in terms of weight and growth rate at all ages. Male hybrids, although sterile, are of economic benefit for meat production and female hybrids can be used for breeding and can produce crossbred progeny with maximal heterosis of interspecies hybridization for production and reproductive fitness.