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Genome wide association study on beef production traits in Marchigiana cattle breed
Summary A genomewide association study was carried out on a sample of Marchigiana breed cattle to detect markers significantly associated with carcass and meat traits. Four hundred and nine young bulls from 117 commercial herds were genotyped by Illumina 50K BeadChip assay. Eight growth and carcass traits (average daily gain, carcass weight, dressing percentage, body weight, skin weight, shank circumference, head weight and carcass conformation) and two meat quality traits (pH at slaughter and pH 24 h after slaughter) were measured. Data were analysed with a linear mixed model that included fixed effects of herd, slaughte...
Source: Journal of Animal Breeding and Genetics - May 31, 2016 Category: Genetics & Stem Cells Authors: S. Sorbolini, S. Bongiorni, M. Cellesi, G. Gaspa, C. Dimauro, A. Valentini, N.P.P. Macciotta Tags: Original Article Source Type: research

Traditional livestock breeding practices of men and women Somali pastoralists: trait preferences and selection of breeding animals
Summary Somalia, one of the world's poorest countries, has livestock as the mainstay of the economy, with an estimated 65% of the population engaged in the livestock sector. This paper presents a gendered study on the traditional livestock breeding practices of Somali pastoralists for camels, cattle, sheep and goats, with a focus on documenting livestock traits of importance, the criteria used to select male breeding animals and the criteria used to cull female breeding animals. Data for the study were obtained by performing participatory rural appraisals (PRAs) with separate male and female pastoral groups from 20 settlem...
Source: Journal of Animal Breeding and Genetics - May 31, 2016 Category: Genetics & Stem Cells Authors: K. Marshall, N. Mtimet, F. Wanyoike, N. Ndiwa, H. Ghebremariam, L. Mugunieri, R. Costagli Tags: Original Article Source Type: research

Prediction of genetic gain in finite populations with heterogeneous predicted breeding values accuracies
Summary The algebraic expression of the genetic selection differential (expected genetic superiority of breeders after a selection on their Predicted Breeding Values) was derived when a limited number of individuals were selected from a limited sample of candidates on the basis of their predicted genetic value, with heterogeneous reliabilities. A formula is proposed for situations in which these reliabilities can be clustered in a few classes. We show that the expected genetic selection differential increases with the number of classes, the mean reliability being constant. In the panel of cases simulated, this increase rea...
Source: Journal of Animal Breeding and Genetics - May 31, 2016 Category: Genetics & Stem Cells Authors: J.‐M. Elsen Tags: Original Article Source Type: research

An evaluation of alternative selection indexes for a non‐linear profit trait approaching its economic optimum
This study used simulation to evaluate the performance of alternative selection index configurations in the context of a breeding programme where a trait with a non‐linear economic value is approaching an economic optimum. The simulation used a simple population structure that approximately mimics selection in dual purpose sheep flocks in New Zealand (NZ). In the NZ dual purpose sheep population, number of lambs born is a genetic trait that is approaching an economic optimum, while genetically correlated growth traits have linear economic values and are not approaching any optimum. The predominant view among theoretical ...
Source: Journal of Animal Breeding and Genetics - May 31, 2016 Category: Genetics & Stem Cells Authors: D. Martin‐Collado, T.J. Byrne, B. Visser, P.R. Amer Tags: Original Article Source Type: research

Analysis of competition performance in dressage and show jumping of Dutch Warmblood horses
Summary Most Warmblood horse studbooks aim to improve the performance in dressage and show jumping. The Dutch Royal Warmblood Studbook (KWPN) includes the highest score achieved in competition by a horse to evaluate its genetic ability of performance. However, the records collected during competition are associated with some aspects that might affect the quality of the genetic evaluation based on these records. These aspects include the influence of rider, censoring and preselection of the data. The aim of this study was to quantify the impact of rider effect, censoring and preselection on the genetic analysis of competiti...
Source: Journal of Animal Breeding and Genetics - May 30, 2016 Category: Genetics & Stem Cells Authors: G. Rovere, B.J. Ducro, J.A.M. Arendonk, E. Norberg, P. Madsen Tags: Original Article Source Type: research

Inbreeding depression in Zebu cattle traits
Summary The productivity of herds may be negatively affected by inbreeding depression, and it is important to know how intense is this effect on the livestock performance. We performed a comprehensive analysis involving five Zebu breeds reared in Brazil to estimate inbreeding depression in productive and reproductive traits. Inbreeding depression was estimated for 13 traits by including the individual inbreeding rate as a linear covariate in the standard genetic evaluation models. For all breeds and for almost all traits (no effect was observed on gestation length), the performance of the animals was compromised by an incr...
Source: Journal of Animal Breeding and Genetics - May 19, 2016 Category: Genetics & Stem Cells Authors: R.J. Pereira, M.L. Santana, D.R. Ayres, A.B. Bignardi, G.R.O. Menezes, L.O.C. Silva, C.H.C. Machado, L.A. Josahkian, L.G. Albuquerque Tags: Original Article Source Type: research

Genomic data and breeding value estimation in dairy cattle: theory, practice, problems
(Source: Journal of Animal Breeding and Genetics)
Source: Journal of Animal Breeding and Genetics - May 11, 2016 Category: Genetics & Stem Cells Authors: E.A. Mäntysaari, I. Strandén Tags: Editorial Source Type: research

Estimating heritability of wool shedding in a cross ‐bred ewe population
Summary Low wool prices and high production costs in sheep systems have resulted in the introduction of genotypes that shed wool into flocks to reduce shearing costs. Wool shedding occurs naturally in a few breeds and can be incorporated by cross‐breeding. The opportunity to enhance shedding through selection depends on the extent of genetic variability present. Genetic and environmental parameters for wool shedding for ewes from a three‐breed composite population were estimated using Bayesian inference. Data on 2025 cross‐bred ewes, including 3345 wool shedding scores (WS) and 1647 breeding weight (BW) records, were...
Source: Journal of Animal Breeding and Genetics - May 3, 2016 Category: Genetics & Stem Cells Authors: N. Vargas Jurado, K.A. Leymaster, L.A. Kuehn, R.M. Lewis Tags: Original Article Source Type: research

Polymorphism in exon 2 encoding the putative ligand binding pocket of the bovine insulin ‐like growth factor 1 receptor affects milk traits in four different cattle breeds
Summary As a member of the somatotropic axis, insulin‐like growth factor I receptor (IGF1R) seems to be a promising candidate gene. Two silent polymorphisms, identified by MspI and TaqI restriction enzymes, were selected within exon 2, encoding the majority of the putative ligand binding pocket. A total of 1169 cows of four pure breeds (Polish Holstein Friesian, Montbeliarde, Jersey and Holstein Friesian) were genotyped. The T (IGF1R/e2/MspI) and G (IGF1R/e2/TaqI) alleles were found to be prevalent. Three combinations of genotypes (TT/GG, TT/AG and CT/GG) were associated with the highest productivity (milk, protein and f...
Source: Journal of Animal Breeding and Genetics - April 25, 2016 Category: Genetics & Stem Cells Authors: M. Szewczuk Tags: Original Article Source Type: research

Relationship between calving difficulty and fertility traits in first ‐parity Iranian Holsteins under standard and recursive models
Summary The main objective of this study was to estimate the genetic and phenotypic relationships between calving difficulty (CD) and fertility traits, including success at first service (SF), number of inseminations to conception (INS), interval from calving to first service (CTFS), interval between first and last service (IFL) and days open (DO), in first‐parity Iranian Holsteins under standard (SMMs) and recursive (RMMs) mixed models. The data analysed in this paper included 29 950 records on CD and fertility traits, collected in the time period from 1995 to 2014 by the Animal Breeding and Improvement Center of Iran....
Source: Journal of Animal Breeding and Genetics - April 16, 2016 Category: Genetics & Stem Cells Authors: M.S. Mokhtari, M. Moradi Shahrbabak, A. Nejati Javaremi, G.J.M. Rosa Tags: Original Article Source Type: research

Relationship between calving difficulty and fertility traits in first‐parity Iranian Holsteins under standard and recursive models
Summary The main objective of this study was to estimate the genetic and phenotypic relationships between calving difficulty (CD) and fertility traits, including success at first service (SF), number of inseminations to conception (INS), interval from calving to first service (CTFS), interval between first and last service (IFL) and days open (DO), in first‐parity Iranian Holsteins under standard (SMMs) and recursive (RMMs) mixed models. The data analysed in this paper included 29 950 records on CD and fertility traits, collected in the time period from 1995 to 2014 by the Animal Breeding and Improvement Center of Iran....
Source: Journal of Animal Breeding and Genetics - April 16, 2016 Category: Genetics & Stem Cells Authors: M.S. Mokhtari, M. Moradi Shahrbabak, A. Nejati Javaremi, G.J.M. Rosa Tags: Original Article Source Type: research

Estimating heritability of wool shedding in a cross‐bred ewe population
Summary Low wool prices and high production costs in sheep systems have resulted in the introduction of genotypes that shed wool into flocks to reduce shearing costs. Wool shedding occurs naturally in a few breeds and can be incorporated by cross‐breeding. The opportunity to enhance shedding through selection depends on the extent of genetic variability present. Genetic and environmental parameters for wool shedding for ewes from a three‐breed composite population were estimated using Bayesian inference. Data on 2025 cross‐bred ewes, including 3345 wool shedding scores (WS) and 1647 breeding weight (BW) records, were...
Source: Journal of Animal Breeding and Genetics - March 31, 2016 Category: Genetics & Stem Cells Authors: N. Vargas Jurado, K.A. Leymaster, L.A. Kuehn, R.M. Lewis Tags: Original Article Source Type: research

A comparison of methods to estimate genomic relationships using pedigree and markers in livestock populations
Summary Accurate prediction of breeding values depends on capturing the variability in genome sharing of relatives with the same pedigree relationship. Here, we compare two approaches to set up genomic relationship matrices for precision of genomic relationships (GR) and accuracy of estimated breeding values (GEBV). Real and simulated data (pigs, 60k SNP) were analysed, and GR were estimated using two approaches: (i) identity by state, corrected with either the observed (GVR‐O) or the base population (GVR‐B) allele frequencies and (ii) identity by descent using linkage analysis (GIBD‐L). Estimators were evaluated for...
Source: Journal of Animal Breeding and Genetics - March 31, 2016 Category: Genetics & Stem Cells Authors: N.S. Forneris, J.P. Steibel, A. Legarra, Z.G. Vitezica, R.O. Bates, C.W. Ernst, A.L. Basso, R.J.C. Cantet Tags: Original Article Source Type: research

Polymorphism in exon 2 encoding the putative ligand binding pocket of the bovine insulin‐like growth factor 1 receptor affects milk traits in four different cattle breeds
Summary As a member of the somatotropic axis, insulin‐like growth factor I receptor (IGF1R) seems to be a promising candidate gene. Two silent polymorphisms, identified by MspI and TaqI restriction enzymes, were selected within exon 2, encoding the majority of the putative ligand binding pocket. A total of 1169 cows of four pure breeds (Polish Holstein Friesian, Montbeliarde, Jersey and Holstein Friesian) were genotyped. The T (IGF1R/e2/MspI) and G (IGF1R/e2/TaqI) alleles were found to be prevalent. Three combinations of genotypes (TT/GG, TT/AG and CT/GG) were associated with the highest productivity (milk, protein and f...
Source: Journal of Animal Breeding and Genetics - March 31, 2016 Category: Genetics & Stem Cells Authors: M. Szewczuk Tags: Original Article Source Type: research

Accuracy of genomic prediction of purebreds for cross bred performance in pigs
The objective of our study was to assess empirically the predictive ability (accuracy) of direct genomic values of PB for CB performance across two traits using CB and PB genomic and phenotypic data. We studied three scenarios in which genetic merit was predicted within each population, and four scenarios where PB genetic merit for CB performance was predicted based on either CB or a PB training data. Accuracy of prediction of PB genetic merit for CB performance based on CB training data ranged from 0.23 to 0.27 for gestation length (GLE), whereas it ranged from 0.11 to 0.22 for total number of piglets born (TNB). When bas...
Source: Journal of Animal Breeding and Genetics - March 31, 2016 Category: Genetics & Stem Cells Authors: A.M. Hidalgo, J.W.M. Bastiaansen, M.S. Lopes, M.P.L. Calus, D.J. Koning Tags: Original Article Source Type: research