Cytogenetic screening of cattle and buffalo breeding bulls

Abstract

Chromosomal abnormalities cause a drop in reproductive performance or even complete infertility/sterility in 
the carrier animals. Present investigation was undertaken to detect chromosomal abnormality, if any, in 155 
breeding bulls of exotic (Bos taurus, 2n=60), indigenous (Bos indicus, 2n=60) cattle, their crossbreeds and 
Murrah buffalo (Bubalus bubalis, 2n = 50) maintained by various organizations. Mitotic chromosome spreads 
were prepared and analysed from cultured lymphocytes of 155 breeding bulls of different indicus, exotic and 
crossbred cattle (Holstein Friesian, Jersey, Red Sindhi and Sahiwal) and 41 Murrah buffalo bulls reserved for 
breeding and maintained at different stations of State Livestock Development Boards from the state of 
Haryana, Punjab, Uttrakhand, Jammu and Kashmir, Rajasthan and Assam. Giemsa staining of chromosomes 
revealed that 98.2% cattle bulls possessed normal chromosome complements. One Holstein-Friesian and one 
HF crossbred bulls were found to be sex chromosome chimeric (60, XX/60, XY). No chromosomal abnormality 
could be detected in any of the Murrah buffalo bulls studied. Such regular cytogenetic screening will not only 
reduce the occurrence of chromosomal abnormalities in dairy animal population but also will save the time 
and cost of rearing the abnormal animals.