2/4 of Application of genetic information to high quality beef production
Beef cattle
The genetic ability of Japanese Black cattle to transmit important economic traits has traditionally been evaluated by the means of selecting potential animals based on pedigree information and estimated capabilities and subjecting them to progeny testing. However, in spite of the high cost and lengthy time spent in this evaluation process, cases are often found where candidate bulls and cows do not possess the genetic ability sufficient for the application. The purpose of the development of genetic tests relevant to economically important carcase characteristics is not to dispense with progeny testing at this time, as it remains the most accurate means currently available to assess the genetic potential of breeding cattle to pass on advantageous economic characteristics to their offspring, but as a preliminary procedure in the process of selecting breeding cattle or feeder cattle.
GH Exon 5
This test represents a method for evaluating Japanese Black cattle for the important economic characteristics of growth rate and the deposition of fat in certain tissue (marbling) using genetic polymorphism of the growth hormone Exon 5. Growth hormone is one of the peptide hormones and has an impact on the growth of cattle by controlling energy flow in the body. GH has been shown to have an impact on fat accumulation in certain tissue of Japanese Black cattle.The GH gene resides on chromosome 19 of cattle. The GH gene consists of a DNA strand that has 5 segments (the segment unit is called exon) which translate into amino acids. Two mutated points were found in the 5th exon of the GH gene of Japanese Black cattle which changes the amino acids at those points, currently this mutation has not been found in any other breed. These variants are called A, B & C therefore there are 6 genotypes AA, AB, AC, BB, BC & CC.