Pakistan being agriculture based country has a great potential in livestock sector. it plays
an important role in the economy of the country. Milk is a balanced diet because it
contains all the essential nutrients like carbohydrates; fats, proteins, vitamins, minerals
and enzymes required for health. In these milk nutrients fat is second most important
component of milk. Primary component of milk fat is triglycerides (triacylglycerols or
TAG) a typical storage form of lipids. OLRI is the major protein that binds, internalizes
and degrades oxidized low density lipoprotein. Ol.Rl as a protein important for oLDL
metabol ism may contribute to these effects. Oxidized fat inhibits the expression of
lipoprotein lipase and fatty acid transporter genes that causes a reduced uptake of fatty
acids into mammary glands. As a result the concentration of triacylglycerols in milk is
reduced. OLRl as a protein important for oLOL metabolism may contribute to these
effects. OLR J identified as a functional and positional candidate gene product for milk fat
percentage and milk fat yield. Polymorphism in Ol.Rl gene increases the milk fat
percentage. If polymorphism in Ol.Rl gene is found in Pakistani Sahiwal and Ohanni
cattle breeds these were help to screen the animals at younger age and also be used to
characterize the different cattle breeds as a milk fat production marker. Unrelated animals
were selected for this study. Blood samples were collected from different Go\'1. livestock
farms/experimental stations. DNA was extracted by organic method. Primers were
designed by using Primer3 software. After DNA amplification by polymerase chain
reaction. peR product was sequenced. Sequencing results of the full length OLR I gene
were analyzed by alignment of sequences with the help of Blast2sequence software.
Novel S Ps were identified. Total of twenty one SNPs were identified in the samples of
all breeds that were confirmed at population level by sequencing of each sample. Then
total twenty one SNPs were found in all breeds. Most of SNPs were found in intronic
regions. In Sahiwal only 5 SNPs are exonic and one of them is common in both Sahiwal
and Red Sindhi breeds. Out of total five exonic SNPs, only two were found synonymous
and rest of the three exonic SNPs were found to be non synonymous. while all other
SNPs are intronic in nature. An intronic SNP is also common between Sahiwal and
Dhanni breed. In Red Sindhi a SNP was observed at 3'UTR. Results were analyzed by.
using the statistical software POPgene32. The mean value of expected heterozygosity that
is 0.3595 is greater than the mean of observed heterozygosity that is 0.0300 that shows
low variabil ity in breeds. The mean value for Shannon's Information index (1*) is 0.5421.
The aim of research is to identify gene that underlie the genetic variation in bovine milk.
fat composition.