Identification of Markers Associated with Birth Weight in Boer Goat

Genetic improvement of breeding depends on selective breeding of superior phenotypes. In order to increase accuracy of breeding and selection for efficient production systems, current trend is towards applying molecular markers. The purpose of the study was to identify markers associated with birth weight in Boer goats using 50k single nucleotide polymorphism (SNP) chip. A total of 657 Boer goats were selected based on the availability of birth weight data from a commercial farm. Individuals were genotyped using 50k SNP chip from Illumina using Illumina Genome Analyzer IIx. A genome wide association analysis using a mixed model was carried out and resulted in 32 detected markers for birth weight. In previous genotyping study done on the same population of goat using 20k custom-designed SNP chip resulted in 14 markers for birth weight. However, markers identified should be verified in an independent population before being applied in a Marker Assisted Selection (MAS) program. Further consideration should be on socio-economic factors as well as their sustainability in biodiverse environments

Биофизика зрительной сенсорной системы человека

Зрительная сенсорная система – это система, которая воспринимает излучение видимого спектра, после чего формируется изображение предметов окружающей среды в виде определенных ощущений (сенсорных чувств)

Application of molecular markers and genomics for diversity growth and meat quality in Malaysian cattle

The overall aims of this present work were to investigate the genetic variation underlying economically important traits in the Malaysian cattle breed Brakmas, and to link identified genetic polymorphisms in growth and meat quality genes using a series of DNA-based markers. Brakmas display a high microsatellite polymorphism but within the range of other studies of less intensively bred cattle. Brakmas do not display evidence for a genetic bottleneck, a decrease in genetic diversity, or loss of alleles, and this indicates that the Brakmas herd is rich reservoir of genetic diversity. This is a strong justification for preservation of the breed apart from others, because of the productivity as well capability of adaptation in the local tropical climates. Sequence polymorphisms were identified in different growth-related genes in the Brakmas population. The polymorphisms identified offer potential markers for growth rate and meat quality. Given the large numbers of polymorphisms between subspecies, verification on effect of associated production traits with the molecular markers has to be established in Brakmas as the effect might be different between breeds. Knowledge of amount and consequences of polymorphisms in livestock is important for the manipulation of meat production in livestock. Understanding of the function of these genes will lead to the development of new genetic markers. It is hoped that knowledge and understanding of nature and polymorphism will provide the basis for future selection to enhance beef production performance as well as for conservation purposes

The Potential of Using Temperate–Tropical Crossbreds and Agricultural by-Products, Associated with Heat Stress Management for Dairy Production in the Tropics: A Review

The demand and consumption of dairy products are expected to increase exponentially in developing countries, particularly in tropical regions. However, the intensification of dairy production to meet this increasing demand has its challenges. The challenges ranged from feed costs, resources, and their utilization, as well as the heat stress associated with rearing temperate–tropical crossbred cattle in the tropics. This article focused on key nutritional and environmental factors that should be considered when temperate–tropical crossbred cattle are used in the tropics. The article also describes measures to enhance the utilization of regional feed resources and efforts to overcome the impacts of heat stress. Heat stress is a major challenge in tropical dairy farming, as it leads to poor production, despite the genetic gains made through crossbreeding of high production temperate cattle with hardy tropical animals. The dependence on imported feed and animal-man competition for the same feed resources has escalated feed cost and food security concerns. The utilization of agricultural by-products and production of stable tropical crossbreds will be an asset to tropical countries in the future, more so when scarcity of feed resources and global warming becomes a closer reality. This initiative has far-reaching impacts in the tropics and increasingly warmer areas of traditional dairying regions in the future

Correction : Design and Characterization of a 52K SNP Chip for Goats

Notice à Reprende pas de Clé UT au 17 Mars 2017 et retravailler les affiliations auteursCorrection : Design and Characterization of a 52K SNP Chip for Goat

Design and Characterization of a 52K SNP Chip for Goats

The success of Genome Wide Association Studies in the discovery of sequence variation linked to complex traits in humans has increased interest in high throughput SNP genotyping assays in livestock species. Primary goals are QTL detection and genomic selection. The purpose here was design of a 50-60,000 SNP chip for goats. The success of a moderate density SNP assay depends on reliable bioinformatic SNP detection procedures, the technological success rate of the SNP design, even spacing of SNPs on the genome and selection of Minor Allele Frequencies (MAF) suitable to use in diverse breeds. Through the federation of three SNP discovery projects consolidated as the International Goat Genome Consortium, we have identified approximately twelve million high quality SNP variants in the goat genome stored in a database together with their biological and technical characteristics. These SNPs were identified within and between six breeds (meat, milk and mixed): Alpine, Boer, Creole, Katjang, Saanen and Savanna, comprising a total of 97 animals. Whole genome and Reduced Representation Library sequences were aligned on >10 kb scaffolds of the de novo goat genome assembly. The 60,000 selected SNPs, evenly spaced on the goat genome, were submitted for oligo manufacturing (Illumina, Inc) and published in dbSNP along with flanking sequences and map position on goat assemblies (i.e. scaffolds and pseudo-chromosomes), sheep genome V2 and cattle UMD3.1 assembly. Ten breeds were then used to validate the SNP content and 52,295 loci could be successfully genotyped and used to generate a final cluster file. The combined strategy of using mainly whole genome Next Generation Sequencing and mapping on a contig genome assembly, complemented with Illumina design tools proved to be efficient in producing this GoatSNP50 chip. Advances in use of molecular markers are expected to accelerate goat genomic studies in coming years

Goat Genome scaffolds assembly.

<p>The goat genome scaffolds were sorted by decreasing size (x-axis) and the cumulative proportion of the assembled genome was plotted on the y-axis for all the scaffolds. The vertical line shows that >10kb scaffolds represent 97.2% of the assembled goat genome.</p

SNP identified in the five breeds or breed pool and in ESTs.

<p>The number on the diagonal is the number of SNPs found in a breed (Alpine, Boer, Creole, Saanen), breed pool (Katjang/Savanna) or in ESTs. Off diagonals are the number of SNPs shared between the two respective breeds.</p

SNP spacing on the goat scaffolds.

<p>Spacing between the selected SNPs was calculated and the percentage of gaps (total number of gaps is 59,030 on goat scaffolds and 62,693 on UMD3.1 cattle assembly) is shown (y-axis) in each 5kb class ranging from 5 to 150kb (x-axis).</p