Heritability of feed intake in grazing Merino ewes and the genetic relationships with production traits

2009 ◽  
Vol 49 (12) ◽  
pp. 1080 ◽  
Author(s):  
N. M. Fogarty ◽  
E. Safari ◽  
S. I. Mortimer ◽  
J. C. Greeff ◽  
S. Hatcher

The feed intake of 1279 mature non-pregnant and non-lactating Merino ewes grazing pasture was estimated by faecal marker dilution methods using rumen controlled-release devices containing chromium sesquioxide capsules. The ewes were from two genetic resource flocks (QPLU$ flock at Trangie in NSW and a Western Australia flock at Katanning) that are representative of the major bloodlines and strains in the Australian Merino population. Pedigree information over several generations was used to genetically link other animals from the resource flocks that had additional production data to allow estimation of genetic correlations between feed intake and production traits with greater accuracy. Data were available for over 16 000 records for growth, wool and reproduction traits from the ewes and their relatives, together with carcass and meat quality traits from over 4000 rams that were slaughtered at ~18 months of age. Feed intake of the ewes was significantly affected by the reproductive status of the ewes at their previous lambing and feed intake, expressed as relative digestible dry matter intake (rDDMI), had an estimated heritability of 0.32 ± 0.08. The genetic correlations between rDDMI and growth traits were positive and larger than their standard error for birth (0.24 ± 0.12) and hogget (0.20 ± 0.09) weight, although inclusion of ewe liveweight as a covariate in the model reduced the correlations to close to zero. Generally, the genetic correlations between rDDMI and the wool, reproduction, carcass and meat quality traits were close to zero and smaller than their standard errors, with little effect of including ewe liveweight as a covariate. The results suggest that feed requirements of ewes could be reduced by selection, although ewe weight and growth would also decline unless accounted for in the model. Practical and cost effective methods of measurement of intake under grazing conditions need to be developed.

2007 ◽  
Vol 58 (8) ◽  
pp. 839 ◽  
Author(s):  
V. M. Ingham ◽  
N. M. Fogarty ◽  
A. R. Gilmour ◽  
R. A. Afolayan ◽  
L. J. Cummins ◽  
...  

The study estimated heritability for lamb growth and carcass performance, hogget ewe wool production, and worm egg count among crossbred progeny of maternal breed sires, as well as the genetic and phenotypic correlations among the traits. The data were from crossbred progeny of 91 sires from maternal breeds including Border Leicester, East Friesian, Finnsheep, Coopworth, White Suffolk, Corriedale, and Booroola Leicester. The sires were mated to Merino ewes at 3 sites over 3 years (and also Corriedale ewes at one site), with 3 common sires used at each site and year to provide genetic links. These sheep comprised part of the national maternal sire central progeny test program (MCPT) to evaluate the genetic variation for economically important production traits in progeny of maternal and dual-purpose (meat and wool) sires and the scope for genetic improvement. The matings resulted in 7846 first-cross lambs born, with 2964 wether lambs slaughtered at an average age of 214 days, and wool data from 2795 hogget ewes. Data were analysed using univariate mixed models containing fixed effects for site, year, sex and type of birth and rearing, dam source and sire breed, and random terms for sire and dam effects. Heritabilities and genetic correlations were estimated based on variances from progeny of 70 sires by fitting the same mixed models using a REML procedure in univariate and multivariate analyses. Estimates of heritability were low for lamb growth traits (0.07–0.29), meat colour and meat pH (0.10–0.23), and faecal worm egg count (0.10), moderate for carcass fat and muscle traits (0.32–0.47), and moderate to high for wool traits (0.36–0.55). Estimates of direct genetic correlations among liveweights at various ages were high and positive (0.41–0.77) and those between liveweights and most carcass and meat quality traits were small and varied in sign. Liveweights were moderately to highly positively correlated with most wool traits, except fibre diameter (–0.28–0.08). The study indicates that there is genetic variation for wool, growth, carcass, and meat quality traits, as well as for faecal worm egg count, with scope for selection within Australian maternal sire breeds of sheep.


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 ◽  
...  

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.


2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 270-271
Author(s):  
Prince P Opoku ◽  
Bimol Roy ◽  
Graham Plastow ◽  
huaigang Lei ◽  
Chunyan Zhang ◽  
...  

Abstract The hypothesis that genetic relationships exist between loin muscle collagen characteristics and sub-primal and meat quality traits was tested. Data from 500 pigs from crosses between Duroc sires and hybrid Large White ✕ Landrace sows with pedigree back to about eight generations were used. Significant fixed effects (slaughter group and company) and a random additive effect were fitted in bivariate animal models to estimate phenotypic and genetic correlations using ASReml 4.1. Moderate heritabilities were obtained for sub-primal traits ranging from 0.21 for bone weight to 0.44 for loin muscle weight with a low estimate of 0.10 being obtained for loin weight. Meat quality traits were low to moderately heritable with the highest estimate being found for intramuscular fat (0.42). The heritability estimates for percentages of heat soluble and insoluble collagen were 0.12 and 0.15, respectively, while 0.33 was found for total collagen. Moderate to relatively high heritabilities imply the possibility of improving these traits through selective breeding. In general, moderate to high phenotypic and genetic correlations were obtained for sub-primal traits, whilst meat quality traits had moderate phenotypic and moderate to high genetic correlations. Strong negative genetic correlations between moisture traits and fat traits and a further negative correlation between fat and muscling traits were estimated confirming that selecting for improved muscling over time can negatively affect fat traits and indirectly decrease meat eating quality. The strong genetic correlation between pH and L* (-0.95) suggested possible pleiotropic gene effects on these traits. Warner-Braztler shear force (WBSF) had moderate genetic correlations with insoluble collagen (0.42) and soluble collagen (-0.38) suggesting a potential relationship between some of the genes impacting these traits. Genetic correlations between WBSF and collagen characteristics indicate that despite the relative youthfulness of pigs at slaughter, genetic selection for collagen solubility may decrease pork toughness.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Simone Savoia ◽  
Andrea Albera ◽  
Alberto Brugiapaglia ◽  
Liliana Di Stasio ◽  
Alessio Cecchinato ◽  
...  

Abstract Background The possibility of assessing meat quality traits over the meat chain is strongly limited, especially in the context of selective breeding which requires a large number of phenotypes. The main objective of this study was to investigate the suitability of portable infrared spectrometers for phenotyping beef cattle aiming to genetically improving the quality of their meat. Meat quality traits (pH, color, water holding capacity, tenderness) were appraised on rib eye muscle samples of 1,327 Piemontese young bulls using traditional (i.e., reference/gold standard) laboratory analyses; the same traits were also predicted from spectra acquired at the abattoir on the intact muscle surface of the same animals 1 d after slaughtering. Genetic parameters were estimated for both laboratory measures of meat quality traits and their spectra-based predictions. Results The prediction performances of the calibration equations, assessed through external validation, were satisfactory for color traits (R2 from 0.52 to 0.80), low for pH and purge losses (R2 around 0.30), and very poor for cooking losses and tenderness (R2 below 0.20). Except for lightness and purge losses, the heritability estimates of most of the predicted traits were lower than those of the measured traits while the genetic correlations between measured and predicted traits were high (average value 0.81). Conclusions Results showed that NIRS predictions of color traits, pH, and purge losses could be used as indicator traits for the indirect genetic selection of the reference quality phenotypes. Results for cooking losses were less effective, while the NIR predictions of tenderness were affected by a relatively high uncertainty of estimate. Overall, genetic selection of some meat quality traits, whose direct phenotyping is difficult, can benefit of the application of infrared spectrometers technology.


2017 ◽  
Vol 95 (10) ◽  
pp. 4260-4273 ◽  
Author(s):  
S. I. Mortimer ◽  
S. Hatcher ◽  
N. M. Fogarty ◽  
J. H. J. van der Werf ◽  
D. J. Brown ◽  
...  

2011 ◽  
Vol 68 (6) ◽  
pp. 620-625 ◽  
Author(s):  
Leila de Genova Gaya ◽  
Gerson Barreto Mourão ◽  
José Bento Sterman Ferraz ◽  
Elisângela Chicaroni de Mattos ◽  
Andrezza Marcovig Moreira Alves da Costa ◽  
...  

2006 ◽  
Vol 57 (9) ◽  
pp. 1029 ◽  
Author(s):  
Meridy J. Kadel ◽  
David J. Johnston ◽  
Heather M. Burrow ◽  
Hans-U. Graser ◽  
Drewe M. Ferguson

Flight time, an objective measure of temperament, was recorded in 3594 Brahman, Belmont Red, and Santa Gertrudis heifers and steers. Two subjective measures of temperament (crush score and flight speed score) were also available for over 2000 of these animals. Temperament measures were recorded post-weaning (average age 8 months) and again at the start of finishing (average age 19 months) on a subset of the animals. Nine meat quality traits were measured on these animals and included measures on 2 different muscles [M. longissimus thoracis et lumborum (LTL) and M. semitendinosus (ST)]. The heritability of flight time measured post-weaning and at the start of finishing was 0.30 and 0.34, respectively, with a repeatability of 0.46 across the measurement times. Heritabilities for scored temperament traits were 0.21, 0.19, and 0.15 for post-weaning flight speed score, post-weaning crush score, and start of finishing crush score, respectively. Genetic correlations across measurement times for flight time were 0.98 and 0.96 for crush score, indicating a strong underlying genetic basis of these temperament measures over time; however, the corresponding phenotypic correlations were lower (0.48 and 0.37, respectively). Longer flight times (i.e. better temperament) were genetically correlated with improved tenderness (i.e. lower shear force and higher tenderness scores), with genetic correlations of –0.42 and 0.33 between LTL shear force, and Meat Standards Australia (MSA) tenderness, respectively. Genetic correlations between post-weaning crush score and the same meat quality traits were 0.39 and –0.47, respectively. However, genetic and phenotypic correlations between measures of temperament and other meat quality traits were generally low, with the exception of crush scores with LTL Minolta a* value (–0.37 and –0.63 for post-weaning and start of finishing measurement time, respectively). Predicted correlated responses of –0.17 kg LTL shear force and 2.6 MSA tenderness points per generation were predicted based on the genetic parameter estimates and a recording regime of both flight time and crush scores. Selection based on the measures of temperament described in this study could be used to improve temperament itself and correlated improvements can also occur in meat tenderness and eating quality traits in tropically adapted breeds of cattle.


2010 ◽  
Vol 50 (12) ◽  
pp. 1135 ◽  
Author(s):  
S. I. Mortimer ◽  
J. H. J. van der Werf ◽  
R. H. Jacob ◽  
D. W. Pethick ◽  
K. L. Pearce ◽  
...  

Using performance from progeny born in 2007 and 2008 generated by the Information Nucleus program of the Cooperative Research Centre for Sheep Industry Innovation, preliminary estimates of heritability were obtained for a range of novel carcass and meat attributes of lamb relevant to consumers, including carcass characteristics, meat quality and nutritional value of lamb. Phenotypic and genetic correlations of live animal traits with carcass composition and meat quality traits were also estimated. The data were from progeny located at eight sites, sired by 183 rams from Merino, maternal and terminal meat breeds and were representative of the Merino, Border Leicester × Merino, Terminal × Merino and Terminal × Border Leicester-Merino production types of the Australian sheep industry. Data were available from 7176 lambs for weaning weight, 6771 lambs for ultrasound scanning and 4110 lambs for slaughter traits. For the novel meat quality traits, generally moderate to high heritability estimates were obtained for meat quality measures of shear force (0.27 aged 1 day, 0.38 aged 5 days), intramuscular fat (0.39), retail meat colour (range of 0.09 to 0.44) and myoglobin content (0.22). The nutritional value traits of omega-3 fatty acids and iron and zinc contents tended to have low to moderate heritabilities (0.11–0.37), although these were based on fewer records. Fresh meat colour traits were of low to moderate heritability (0.06–0.21) whereas measures of meat pH were of low heritability (~0.10). For the carcass traits, estimates of heritability were moderate to high for the various measures of carcass fat (0.18–0.50), muscle weight (0.22–0.35), meat yield (0.24–0.35), carcass muscle dimensions (0.25–0.34) and bone weight (0.27). Results indicate that for most lamb carcass and meat quality traits there is sufficient genetic variation for selection to alter successfully these characteristics. Additionally, most genetic correlations of live animal assessments of bodyweight, muscle and subcutaneous fat with the carcass and meat quality traits were favourable. Appropriate definition of breeding objectives and design of selection indexes should be able to account for the small unfavourable relationships that exist and achieve the desired outcomes from breeding programs.


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