Genetic relationships between internal parasite resistance and production traits in Merino sheep

2017 ◽  
Vol 57 (2) ◽  
pp. 209 ◽  
Author(s):  
D. J. Brown ◽  
N. M. Fogarty
Keyword(s):  
Genetic Parameters ◽  
Genetic Correlations ◽  
Production Traits ◽  
Parasite Resistance ◽  
Breeding Programs ◽  
Sheep Breeding ◽  
Breeding Values ◽  
Merino Sheep ◽  
Internal Parasite ◽  
Australian Sheep

Breeding Merino sheep that are resistant to internal parasites alleviates the high costs associated with treatment of worm infestation and loss of production, as well as mitigating the development of anthelmintic resistance among the major worm species. Faecal worm egg count ((cube root transformation), wec) can be used in sheep as a measure of internal parasite resistance. Accurate estimates of genetic parameters for wec are required for calculation of Australian Sheep Breeding Values and inclusion of worm resistance in sheep breeding programs. This study provides updated estimates of heritability for wec and its genetic correlations with production traits. Data were analysed from a wide range of Australian and New Zealand Merino sheep in the MERINOSELECT database, which included 141 flocks with 801 flock years and up to 217 137 animals with wec recorded in at least one of four ages (W = weaning, P = post weaning, Y = yearling, H = hogget). The heritability estimates ranged from 0.16 ± 0.01 for Ywec to 0.29 ± 0.01 for Wwec, with generally high genetic correlations between the ages. Bivariate analyses estimated genetic correlations between wec at the various ages and growth, carcass quality, reproduction and wool production traits at various ages. These genetic correlations were generally small or close to zero, albeit with some significantly different from zero. The moderate heritability for wec (0.2–0.3) and its high phenotypic variation (coefficient of variation >30%) shows that relatively rapid selection response for worm resistance could be achieved. Inclusion of wec in sheep breeding programs to increase worm resistance would be expected to have little if any impact on other important production traits. These genetic parameters have been incorporated into MERINOSELECT by Sheep Genetics to provide Australian Sheep Breeding Values for wec and appropriate indices for wool and meat production. There is evidence that genotype × environment interactions may be important in some environments by reducing the accuracy of Australian Sheep Breeding Values for wec. Hence it may be prudent for breeders to implement strategies that manage the risk of any impact of genotype × environment on their breeding program.

Genetic importance of fat and eye muscle depth in Merino breeding programs

2016 ◽  
Vol 56 (4) ◽  
pp. 690 ◽  
Author(s):  
D. J. Brown ◽  
A. A. Swan
Keyword(s):  
Carcass Traits ◽  
Genetic Correlations ◽  
Fibre Diameter ◽  
Economic Index ◽  
Parasite Resistance ◽  
Eye Muscle ◽  
Breeding Programs ◽  
Dual Purpose ◽  
Internal Parasite ◽  
Reproduction Traits

Australian Merino breeders have traditionally selected animals for breeding predominately on the basis of wool characteristics. Over recent decades, an increasing proportion of Merino breeders are interested in producing a ewe that can be used for prime-lamb production, but that also performs well for wool characteristics. Correlations between ultrasound carcass traits and other traits such as wool, internal parasite resistance and reproduction traits, are not very well known. The aims of this study were three-fold: (1) to estimate the genetic relationships between ultrasound carcass traits and wool, internal parasite resistance and reproduction traits, (2) to determine the value of recording ultrasound carcass traits in Merino breeding programs, and (3) to evaluate the impact of improving ewe genetic merit for fatness on their reproduction performance. Ultrasound fat and eye muscle depth had small to moderate genetic correlations with most traits, with positive correlations observed for bodyweight, fibre diameter, fibre curvature and reproduction, and negative correlations observed for fleece weight, fibre diameter coefficient of variation, worm egg count and breech wrinkle. As expected on the basis of these genetic correlations, estimated breeding values for fat depth of ewes had a positive association with their observed reproduction performance, but the effect explained only minimal variation in reproductive performance, and was extremely variable among flocks and years. A range of measurement scenarios was investigated for three standard MERINOSELECT indexes. Measuring fat and eye muscle depth resulted in 3%, 4% and 21% additional economic index gain for the fine, medium and dual purpose indexes, respectively, whereas measuring reproduction traits directly resulted in 17%, 27% and 45% additional gain in the economic index. Dual purpose index gains benefited more from measuring ultrasound carcass traits as it is the only index with a direct economic value placed on carcass traits. Measuring fat and eye muscle depth also resulted in a greater reduction in worm egg count. The results indicated that desirable genetic progress can be made in wool, ultrasound carcass, internal parasite resistance and number of lambs born and weaned simultaneously using multiple trait selection to account for the mix of favourable and unfavourable correlations between these traits. These results also demonstrated that the best method to maximise economic gain is to measure as many traits (or closely correlated traits) in the breeding objective as possible.

The genetic foundation of fitness and reproduction traits in Australian pig populations. 2. Relationships between weaning to conception interval, farrowing interval, stayability, and other common reproduction and production traits.

1996 ◽  
Vol 47 (8) ◽  
pp. 1275 ◽  
Author(s):  
E Tholen ◽  
KL Bunter ◽  
S Hermesch ◽  
HU Graser
Keyword(s):  
Genetic Parameters ◽  
Performance Test ◽  
Genetic Relationships ◽  
Average Daily Gain ◽  
Genetic Correlations ◽  
Data Sets ◽  
Production Traits ◽  
Breeding Programs ◽  
Reproduction Traits ◽  
Daily Gain

Data sets from 2 large Australian piggeries were used to estimate genetic parameters for the traits weaning to conception interval (WCIi-l,i) and farrowing interval (FIi-l,i), number born alive (NBAI), average piglet birthweight (BWi), 21-day litter weight (W21i), and sow stayability (STAYli) recorded for each ith parity, as well as sow average daily gain (ADG) and backfat (BF) recorded at the end of performance test. Over parities and herds, heritabilities for each trait were in the ranges: WCI/FI, 0.0-0.10; NBA, 0.09-0.16; BW, 0.11-0.35; W21, 0.12-0.23; STAYli, 0.02-0.09; ADG, 0.35-0.37; BF, 0.36-0.45. Genetic correlations between NBAl and NBA from later parities were significantly different from 1. In addition, in 1 herd negative genetic correlations (rg = -0.04 to -0.25) were found between sow stayability traits and NBA1, but not NBA recorded in later parities. Stayability was Unfavourably correlated with ADG and BF, and favourably correlated with WCI12. However, WCI12 was unfavourably correlated genetically with BF (rg = -0.24) but uncorrelated with ADG. Antagonistic relationships also existed between NBA and BW, NBA and W21, and BW and STAY. In addition to the traditional traits currently included in pig-breeding programs (e.g. ADG, BF, and NBA), traits such as WCI, BW, and STAY should also be considered as selection criteria to minimise the detrimental effects of antagonistic genetic relationships between traits.

scholarly journals Estimates of genetic parameters and cluster analyses for carcass and meat quality traits in birds

2017 ◽  
Vol 52 (3) ◽  
pp. 205-213 ◽  
Author(s):  
Adriane Molardi Bainy ◽  
Rodrigo Pelicioni Savegnago ◽  
Luara Afonso de Freitas ◽  
Beatriz do Nascimento Nunes ◽  
Jaqueline Oliveira Rosa ◽  
...  
Keyword(s):  
Meat Quality ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Meat Production ◽  
Quality Traits ◽  
Production Traits ◽  
Multiple Trait ◽  
Breeding Values ◽  
Cluster Analyses ◽  
Meat Quality Traits

Abstract: The objective of this work was to estimate genetic parameters for bird carcass and meat quality traits, as well as to explore the genetic patterns of the breeding values of this population using cluster analyses. Data from 1,846 birds were used to estimate the genetic parameters of production and quality traits using the multiple-trait animal model, and cluster analyses were performed. The heritability estimates ranged from 0.08± 0.03 for meat pH measured 24 hours after slaughter to 0.85± 0.09 for body weight. The genetic correlations between production traits were high and positive. The genetic correlations between meat quality traits were low and were not informative due to the high standard errors (same magnitudes as those of the genetic correlations). The genetic correlations between meat production and quality traits were negative, except between production traits and meat lightness intensity. Based on breeding values (EBVs), the evaluated population can be divided into four groups through cluster analyses, and one group is suitable for selection because the birds presented EBVs above and around the average of the population, respectively, for production and quality traits. Therefore, it is possible to obtain genetic gains for production-related traits without decreasing meat quality.

Using Australian Sheep Breeding Values to increase lean meat yield percentage

2010 ◽  
Vol 50 (12) ◽  
pp. 1098 ◽  
Author(s):  
G. E. Gardner ◽  
A. Williams ◽  
J. Siddell ◽  
A. J. Ball ◽  
S. Mortimer ◽  
...  
Keyword(s):  
Carcass Composition ◽  
Production Traits ◽  
Eye Muscle ◽  
Meat Yield ◽  
Sheep Breeding ◽  
Breeding Values ◽  
Lean Meat ◽  
Target Weight ◽  
Australian Sheep ◽  
The Impact

This study describes the impact of Australian Sheep Breeding Values (ASBV) for post-weaning weight (PWWT), C-site fatness (PFAT) and eye muscle depth (PEMD) on lamb carcasses within the Australian Sheep Industry CRC Information Nucleus Flock. These results are taken from the 2007 drop progeny, consisting of ~2000 lambs slaughtered at a target weight of 21.5 kg. These lambs were the progeny of sires selected to ensure genetic diversity across various production traits. As expected, the PWWT ASBV increased weight at slaughter, and hot standard carcass weight. Dressing percentage was markedly improved by increasing PEMD ASBV, thus prime lamb producers will be maintaining an animal of similar weight on farm, but delivering a markedly larger carcass at slaughter. Lean meat yield % (LMY%) was highest in the progeny of sires with low PFAT ASBV, which decreased whole carcass fatness and increased muscularity. PWWT ASBV affected carcass composition but had little impact on LMY%, as the decreased fatness was largely offset by increased bone, with relatively little change in muscle content. Lastly, PEMD ASBV had little impact on whole carcass LMY%, but did appear to cause some level of muscle redistribution to the higher value loin cuts, in turn increasing the value of the carcass lean.

Genetic parameters for bodyweight, wool, and disease resistance and reproduction traits in Merino sheep. 1. Description of traits, model comparison, variance components and their ratios

2008 ◽  
Vol 48 (9) ◽  
pp. 1177 ◽  
Author(s):  
A. E. Huisman ◽  
D. J. Brown ◽  
A. J. Ball ◽  
H.-U. Graser
Keyword(s):  
Model Comparison ◽  
Genetic Parameters ◽  
Fibre Diameter ◽  
Genetic Effect ◽  
Parasite Resistance ◽  
Merino Sheep ◽  
Internal Parasite ◽  
Reproduction Traits ◽  
Genetic Evaluations ◽  
Resistance Traits

Both wool and sheep meat industries are interested in sheep that have a high reproduction performance and are resistant to internal parasites, in addition to the traditional traits. There is considerable interest in breeding sheep for wool, carcass, reproductive and internal parasite resistance traits simultaneously. The objective of this study was to estimate single trait genetic parameters for 40 traits recorded in Merino sheep, covering bodyweight, carcass, wool, reproduction and internal parasite resistance traits. This also involved determining the appropriate models. The results from this study will be used to review the genetic parameters used in the routine genetic evaluations conducted by Sheep Genetics. The most appropriate models included a maternal genetic effect and covariance between direct and maternal genetic effects for most of the bodyweight traits, greasy and clean fleece weight, fibre diameter and coefficient of variation of fibre diameter. The permanent environment due to the dam was not included for any trait. There was considerable genetic variation in most traits analysed; lowest heritabilities (0.09–0.10) were found for number of lambs born and weaned per lambing opportunity, and highest heritabilities (0.62–0.77) for fibre diameter. The estimated heritabilities and genetic variances, in combination with the estimated correlations, indicate that there is potential to make genetic improvement in most traits currently recorded in Australian Merino sheep.

scholarly journals Estimation of genetic parameters and accuracy of genomic prediction for production traits in Duroc pigs

2019 ◽  
Vol 64 (No. 4) ◽  
pp. 160-165 ◽  
Author(s):  
Bryan Irvine Lopez ◽  
Vanessa Viterbo ◽  
Choul Won Song ◽  
Kang Seok Seo
Keyword(s):  
Genomic Prediction ◽  
Genetic Parameters ◽  
Average Daily Gain ◽  
Genetic Correlations ◽  
Single Step ◽  
Production Traits ◽  
Muscle Area ◽  
Genomic Breeding ◽  
Breeding Values ◽  
Heritability Estimates

Abstract: Genetic parameters and accuracy of genomic prediction for production traits in a Duroc population were estimated. Data were on 24 828 purebred Duroc pigs born in 2000–2016. After quality control procedures, 30 263 single nucleotide polymorphism markers and 560 animals remained that were used to predict the genomic breeding values of individuals. Accuracies of predicted breeding values for average daily gain (ADG), backfat thickness (BF), loin muscle area (LMA), lean percentage (LP) and age at 90 kg (D90) between pedigree-based and single-step methods were compared. Analyses were carried out with a multivariate animal model to estimate genetic parameters for production traits while univariate analyses were performed to predict the genomic breeding values of individuals. Heritability estimates from pedigree analysis were moderate to high. Heritability estimates and standard error for ADG, BF, LMA, LP and D90 were 0.35 ± 0.01, 0.35 ± 0.11, 0.24 ± 0.04, 0.42 ± 0.11 and 0.37 ± 0.03, respectively. Genetic correlations of ADG with BF and LP were low and negative. Genetic correlations of LMA with ADG, BF, LP and D90 were –0.37, –0.27, 0.48 and 0.31, respectively. High correlations were observed between ADG and D90 (–0.98), and also between BF and LP (–0.93). Accuracies of genomic breeding values for ADG, BF, LMA, LP and D90 were 0.30, 0.33, 0.38, 0.40 and 0.28, respectively. Corresponding accuracies using pedigree-based method were 0.29, 0.32, 0.38, 0.39 and 0.27, respectively. The results showed that the single-step method did not show significant advantage compared to the pedigree-based method.

scholarly journals Does the Acknowledgement of αS1-Casein Genotype Affect the Estimation of Genetic Parameters and Prediction of Breeding Values for Milk Yield and Composition Quality-Related Traits in Murciano-Granadina?

Animals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 679 ◽  
Author(s):  
María Gabriela Pizarro Inostroza ◽  
Vincenzo Landi ◽  
Francisco Javier Navas González ◽  
Jose Manuel León Jurado ◽  
Amparo Martínez Martínez ◽  
...  
Keyword(s):  
Milk Yield ◽  
Milk Fat ◽  
Dry Matter ◽  
Production Efficiency ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Increase Production Efficiency ◽  
Breeding Programs ◽  
Breeding Values ◽  
Males And Females

A total of 2090 lactation records for 710 Murciano-Granadina goats were collected during the years 2005–2016 and analyzed to investigate the influence of the αS1-CN genotype on milk yield and components (protein, fat, and dry matter). Goats were genetically evaluated, including and excluding the αS1-CN genotype, in order to assess its repercussion on the efficiency of breeding models. Despite no significant differences being found for milk yield, fat and dry matter heritabilities, protein production heritability considerably increased after aS1-CN genotype was included in the breeding model (+0.23). Standard errors suggest that the consideration of genotype may improve the model’s efficiency, translating into more accurate genetic parameters and breeding values (PBV). Genetic correlations ranged from −0.15 to −0.01 between protein/dry matter and milk yield/protein and fat content, while phenotypic correlations were −0.02 for milk/protein and −0.01 for milk/fat or protein content. For males, the broadest range for reliability (RAP) (0.45–0.71) was similar to that of females (0.37–0.86) when the genotype was included. PBV ranges broadened while the maximum remained similar (0.61–0.77) for males and females (0.62–0.81) when the genotype was excluded, respectively. Including the αS1-CN genotype can increase production efficiency, milk profitability, milk yield, fat, protein and dry matter contents in Murciano-Granadina dairy breeding programs.

Genetic analysis of docility score of Australian Angus and Limousin cattle

2018 ◽  
Vol 58 (2) ◽  
pp. 213 ◽  
Author(s):  
S. F. Walkom ◽  
M. G. Jeyaruban ◽  
B. Tier ◽  
D. J. Johnston
Keyword(s):  
Adverse Effect ◽  
Animal Model ◽  
Genetic Analysis ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Production Costs ◽  
Breeding Value ◽  
Maternal Behaviour ◽  
Production Traits ◽  
Subjective Score

The temperament of cattle is believed to affect the profitability of the herd through impacting production costs, meat quality, reproduction, maternal behaviour and the welfare of the animals and their handlers. As part of the national beef cattle genetic evaluation in Australia by BREEDPLAN, 50 935 Angus and 50 930 Limousin calves were scored by seedstock producers for temperament using docility score. Docility score is a subjective score of the animal’s response to being restrained and isolated within a crush, at weaning, and is scored on a scale from 1 to 5 with 1 representing the quiet and 5 the extremely nervous or anxious calves. Genetic parameters for docility score were estimated using a threshold animal model with four thresholds (five categories) from a Bayesian analysis carried out using Gibbs sampling in THRGIBBS1F90 with post-Gibbs analysis in POSTGIBBSF90. The heritability of docility score on the observed scale was 0.21 and 0.39 in Angus and Limousin, respectively. Since the release of the docility breeding value to the Australian Limousin population there has been a favourable trend within the national herd towards more docile cattle. Weak but favourable genetic correlations between docility score and the production traits indicates that docility score is largely independent of these traits and that selection to improve temperament can occur without having an adverse effect on growth, fat, muscle and reproduction.

scholarly journals Genetic parameters of production and reproduetive traits in on a farm tested Danish Large White and Landrace swine in Greece

2000 ◽  
Vol 43 (3) ◽  
pp. 287-298
Author(s):  
J. Bizelis ◽  
A. Kominakis ◽  
E. Rogdakis ◽  
F. Georgadopoulou
Keyword(s):  
Maximum Likelihood ◽  
Genetic Correlation ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Production Traits ◽  
Likelihood Methods ◽  
Large White ◽  
Reproduction Traits ◽  
Maximum Likelihood Methods ◽  
Genetic And Phenotypic Correlations

Abstract. Production and reproduetive traits in Danish Landrace (LD) and Large White (LW) swine were analysed by restricted maximum likelihood methods to obtain heritabilities as well as genetic and phenotypic correlations. Production traits were: age, backfat thickness (BT), muscle depth (MD) and the ratio BT/MD, adjusted to Standard bodyweight of 85 kg. Reproduction traits were: number of pigs born (NB) and number of pigs weaned (NW) per sow and parity. Heritabilities for age, BT, MD and BT/MD were 0.60, 0.44, 0.51 and 0.42 for LD and 0.36, 0.44, 0.37 and 0.45 for LW, respectively. Genetic correlations between age and BT were −0.22 in LD and – 0.44 in LW. The genetic correlation between age and MD was close to zero in both breeds. Genetic correlation between BT and MD were −0.36 and −0.25 in LD and LW, respectively. Heritabilities for NB were 0.25 in LD and 0.13 in LW while heritabilities for NW were close to zero in both breeds. Genetic correlation between NB and NW was 0.46 and 0.70 in LD and LW, respectively.

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