Of 1.04 million expressed sequence tag (EST) sequences, 95.0% were contained in the assembled contigs. In the Btau4.0 assembly, 90% of the total genome sequence was placed on the 29 autosomes and X chromosome and validated ( 3). The contig N50 (50% of the genome is in contigs of this size or greater) is 48.7kb for both assemblies the scaffold N50 for Btau4.0 is 1.9 Mb. Btau4.0, which includes finished sequence data and used different mapping methods to place the sequence on chromosomes, was used for all global analyses other than gene prediction.

Btau3.1 was used for gene-specific analyses. The most recent assemblies, Btau3.1 and Btau4.0, combined bacterial artificial chromosome (BAC) and whole genome shotgun (WGS) sequences. The cattle genome was assembled with methods similar to the rat and sea urchin genomes ( 3, 4). Since then, over 800 cattle breeds have been established representing an important world heritage and an enabling scientific resource for understanding the genetics of complex traits. These biological processes have been exploited by humans since domestication, which began in the Near East some 8,000-10,000 years ago ( 2). Cattle represent the Ruminantia, which occupy diverse terrestrial environments with their ability to efficiently convert low quality forage into energy-dense fat, muscle and milk. Cattle belong to a phylogenetically distant clade compared to humans and rodents, the Cetartiodactyl order of eutherian mammals, which first appeared ∼60 million years ago ( 1). The effect of genotype on fat percentage was also found to be non-significant in cattle.Domesticated cattle ( Bos taurus and Bos taurus indicus) provide a significant source of nutrition and livelihood to nearly 6.6 billion humans. The non-significant differences of allelic frequency amongst Bos indicus, Bos taurus and crossbred cattle was observed. The weighted frequency of A allele was highest in Indian cattle and lowest in crossbred cattle while the frequency in taurine cattle was found to be in between indicus and crossbred cattle. The allelic frequency of A varied from 0.20 to 0.30 in Bos indicus cattle breeds and 0.19 to 0.34 in Bos taurus breeds while in crossbred cattle the frequency was estimated as 0.21.

The frequency of B allele was comparatively higher than that of A allele. Two alleles A and B and three genotypes AA, AB and BB were observed in all the cattle breeds. The polymorphism at beta-lactoglobulin gene was detected by conducting PCR-RFLP studies on 398 bp fragment spanning over 104 bases of exon IV and 294 bases of intron IV. The study was carried out on eight Bos indicus cattle breeds namely, Sahiwal, Tharparkar, Nimari, Khilari, Deoni, Amritmahal, Hariana and Hilly cattle two Bos taurus cattle breeds namely, Jersey and Holstein Friesian and Indicine Taurine crossbred cattle to find out the polymorphic pattern of beta-lactoglobulin gene. Shivakumar, Pushpendra Kumar, Arjava Sharma Ī Comparison on Polymorphism of Beta-lactoglobulin Gene in Bos indicus, Bos taurus and Indicine×Taurine Crossbred Cattle Asian-Australasian Journal of Animal Sciences 2004 17(6): 733-736.

Taurine cattle