Karakterisasi fenotipe dan potensi genetic serta hubungannya dengan produktivitas dan kualitas daging sapi local Ciamis Jawa Barat

Abstract

Ciamis local cattle is a genetic resources that could support meat selfsufficiency particularly in West Java. The introduction of artificial insemination in Ciamis district has been carried out intensively, therefore ciamis local cattle as a genetic resources will dissapear and getting extinct. The identification of qualitative and quantitative traits including their genetic potencies were required for genetic resources development in order to support sustainable meat availability. Leptin and SCD1 (Stearoyl CoA Desaturase1) genes are potential candidates for genetic selection in the livestocks, and they involved in physiological processes. It assumed that polymorphism of Leptin and SCD1 were significantly associated with the productivity, meat quality and fatty acid composition. This study aimed to: 1) identify qualitative and quantitative traits of ciamis cattle, 2) identify the genetic polymorphism, as well as their phylogenetic, 3) identify Leptin polymorphism and their association with productivity and meat quality, and 4) identify polymorphism on SCD1 gene and their association with meat fatty acid composition. The qualitative and quantitative traits were characterized by using 92 over three years old cows. The observed parameters consist of coat colour, body weight and morphological measurements. The average daily gain (ADG) and carcass percentage were observed from 18 and 14 bulls, respectively. They were fatten on concentrates and rice straw for 58 days. Microsatellite loci, i.e INRA35, HEL9, and BM2113, of 92, 78 and 96 samples, respectively were used to analyze the genetic diversity and its phylogenetic tree. Direct sequencing was carried out using 78 samples to identify polymorphism of Leptin gene and their association with ADG, carcass percentage and meat quality, were analysed using 18, 14 and 14 samples, respectively. PCR-RFLP method with AciI restricted enzym was carried out using 14 samples with different genotypes to identify SCD1 gene polymorphism out of 98 samples and their association with meat fatty acid composition. The result showed that the red-brownish coat colour was predominant in ciamis cattle. About 45.0% of population in Tambaksari, and 48.1% of population in Cijulang were proofed this results. The ciamis cattle had frame size between bali and PO cattle. The local cattle in Cijulang subpopulation were larger significantly than Tambaksari subpopulation. This might be due to highly introduction of PO cattle in Cijulang subpopulation. The ADG of ciamis cattle was 0.62 kg ± 0.23 kg/head/day, and their carcass percentage was 51.61% ± 1.8%. Their carcass percentage was similarly with bali, PO, and crossbred cattle. Ciamis cattle had high level of heterozygosity. The genetic diversity of cattle in Tambaksari subpopulation was higher than in Cijulang subpopulation. The cattle in Ciamis has a closer genetic distance with the PO cattle. Leptin gene of ciamis cattle was polymorphic, and there were two single nucleotide polymorphisms (SNPs) i.e Arg25Cys and Arg25His. It was found three alleles i.e C, T and H, with the frequencies were 55.5 %, 29.5% and 15.4%, respectively. The new mutation (H allele) was found at Arg25His position, convert amino acid code from arginine to histidine. Leptin gene polymorphisms of ciamis cattle was in high category. There were no association between Leptin gene polymorphisms with ADG, carcass percentage, and meat quality of ciamis cattle. SCD1 gene of cattle in Ciamis were polymorphic. There was a SNP at Val293Ala position, convert amino acid code from valin to alanin. It was found two alleles i.e. C and T, with the frequencies were 74.5 % and 25.5%, respectively. Heterozygosity of SCD1 gene in ciamis cattle was in medium category. There was no association between SCD1 gene polymorphisms with meat fatty acid composition. The predominant coat colour of ciamis cattle were red-brownish, and their frame size between bali and PO cattle. Their ADG was relatively low with high carcass percentage. The genetic distance of ciamis cattle was closed with PO cattle. Leptin and SCD1 were polymorphic, eventhough the genotype differences on each gene did not influenced to productivity, meat quality, and meat fatty acid composition of ciamis cattle.