the objective of this study was to determine the polymorphism of bovine β-lactoglobulin (β-lg) gene and its association with milk production traits in iranian najdi cattle. blood samples were collected from 80 najdi cattle from the najdi cattle breeding station located in shoshtar, khuzestan. polymerase chain reaction (pcr) and restriction fragment length polymorphism (rflp) techniqus were used...

in this study we estimated the allele and genotype frequencies of scd1 and dgat1 gene polymorphism. the analysis was conducted on 408 holstein cows from five dairy herds in isfahan province. genotypes were identified using pcr-rflp technique. two genetic variants (a and v) of the scd1 gene were observed in this experiment. the frequency of a-allele ranged from 0.49 to 0.66, while frequency of v...

BACKGROUND Genomic prediction and quantitative trait loci (QTL) mapping typically analyze one trait at a time but this may ignore the possibility that one polymorphism affects multiple traits. The aim of this study was to develop a multivariate Bayesian approach that could be used for simultaneously elucidating genetic architecture, QTL mapping, and genomic prediction. Our approach uses informa...

osteopontin gene is located at the end of chromosome 6 in cattle and it is one of the most important genes influence on milk protein percentage and reproduction. in this study, blood samples were collected from100 brown swiss cows and dna was extracted from whole blood by modified salting out procedure. cows were genotyped for single nucleotide polymorphism of intron iv by pcr-rflp and bsri res...

In Australia, dairy cattle account for ~12% of the nation’s agricultural greenhouse-gas (GHG) emissions. Genetic selection has had a positive impact, reducingGHGemissions fromdairy systemsmainly due to increased production per cow,which has led to (1) requiring fewer cows to produce the same amount ofmilk and (2) lowering emissions per unit of milk produced (emission intensity). The objective o...

The somatotrophic axis (GH-IGF) is a key regulator of animal growth and development, affecting performance traits that include milk production, growth rate, body composition, and fertility. The aim of this study was to quantify the association of previously identified SNPs in bovine growth hormone (GH1) and insulin-like growth factor 1 (IGF-1) genes with direct performance trait measuremen...

In this study the benefit of metabolome level analysis for the prediction of genetic value of three traditional milk traits was investigated. Our proposed approach consists of three steps: First, milk metabolite profiles are used to predict three traditional milk traits of 1,305 Holstein cows. Two regression methods, both enabling variable selection, are applied to identify important milk metab...

Test-day milk yield and somatic cell count data over extended lactation (lactation to 540-600 days) were analysed considering part lactations as different traits and fitting random regression (RR) models. Data on Australian Jersey and Holstein Friesian (HF) were used to demonstrate the shape of the lactation curve and data on HF were used for genetic study. Test-day data from about 100 000 cows...

Breed additive and non-additive effects, and genetic parameters of lactation milk yield (LYD), 305-day milk yield (305YD), lactation length (LL), milk yield per day of lactation (DM) and lifetime milk yield (LTYD) were estimated in Ethiopian Boran cattle and their crosses with Holstein in central Ethiopia. The data analyzed included 2360 lactation records spread over 15 years. Ethiopian Boran c...

the aim of this study was to estimate genetic parameters of age at first calving and its relationship with productive traits of holstein dairy cows. a total of 24491 first lactation records (2x 305d) which were collected from 1995 to 2009 were used. the general linear model (glm) procedure was applied to determine effective factors on studied traits. herd-year-season (hys) and age at first calv...