Genetic parameters for terminal sires estimated using data of progeny from Border Leicester × Merino ewes

1995 ◽  
Vol 46 (4) ◽  
pp. 703
Author(s):  
PA Kenney ◽  
ME Goddard ◽  
LP Thatcher
Keyword(s):  
Genetic Parameters ◽  
Selection Index ◽  
Genetic Correlations ◽  
Subcutaneous Fat ◽  
Muscle Area ◽  
Eye Muscle ◽  
Bone Length ◽  
Selection For ◽  
Using Data ◽  
Omental Fat

Three and a half thousand lambs from Border Leicester x Merino ewes mated to 133 sires from five Poll Dorset, one White Suffolk, one Siromt, two Meridale and four Merino studs were slaughtered, their carcasses halved and one side divided into six primals. Subcutaneous fat was dissected from all six primals, and bone from only the three rear primals. There were four slaughter groups: average slaughter weights of 30 and 35 kg for ewes and 35 and 45 kg for cryptorchids. Heritabilities and phenotypic and genetic correlations for all traits measured (>50) are published in an appendix. Where comparisons were available, estimates were similar to those for purebred animals. Genetic parameters for various assessments of fat were similar except for channel and omental fat. The GR fat depth was the best predictor for total subcutaneous fat, cannon bone length for total bone, and eye muscle area for total soft tissue. Carcass weight and GR appear to be the most important measurements for use in selection for breeding of sires for the prime lamb industry. Slaughter weight and fat depth at the C site could be used as suitable alternatives on live animals. Production of lean meat is not likely to be increased greatly by including measurements other than liveweight and GR in a selection index. Of the other measurements bone length and eye muscle measurements showed most promise.

Corrigendum - Genetic parameters for terminal sires estimated using data of progeny from Border Leicester × Merino ewes

1995 ◽  
Vol 46 (4) ◽  
pp. 703
Author(s):  
PA Kenney ◽  
ME Goddard ◽  
LP Thatcher
Keyword(s):  
Genetic Parameters ◽  
Selection Index ◽  
Genetic Correlations ◽  
Subcutaneous Fat ◽  
Muscle Area ◽  
Eye Muscle ◽  
Bone Length ◽  
Selection For ◽  
Using Data ◽  
Omental Fat

Three and a half thousand lambs from Border Leicester x Merino ewes mated to 133 sires from five Poll Dorset, one White Suffolk, one Siromt, two Meridale and four Merino studs were slaughtered, their carcasses halved and one side divided into six primals. Subcutaneous fat was dissected from all six primals, and bone from only the three rear primals. There were four slaughter groups: average slaughter weights of 30 and 35 kg for ewes and 35 and 45 kg for cryptorchids. Heritabilities and phenotypic and genetic correlations for all traits measured (>50) are published in an appendix. Where comparisons were available, estimates were similar to those for purebred animals. Genetic parameters for various assessments of fat were similar except for channel and omental fat. The GR fat depth was the best predictor for total subcutaneous fat, cannon bone length for total bone, and eye muscle area for total soft tissue. Carcass weight and GR appear to be the most important measurements for use in selection for breeding of sires for the prime lamb industry. Slaughter weight and fat depth at the C site could be used as suitable alternatives on live animals. Production of lean meat is not likely to be increased greatly by including measurements other than liveweight and GR in a selection index. Of the other measurements bone length and eye muscle measurements showed most promise.

Genetic parameters among growth and carcass traits of Canadian Charolais cattle

2004 ◽  
Vol 84 (4) ◽  
pp. 589-597 ◽  
Author(s):  
D. H. Crews ◽  
Jr., M. Lowerison ◽  
N. Caron ◽  
R. A. Kemp
Keyword(s):  
Fixed Effects ◽  
Genetic Parameters ◽  
Growth Traits ◽  
Carcass Traits ◽  
Genetic Correlations ◽  
Subcutaneous Fat ◽  
Field Performance ◽  
Pedigree Data ◽  
Marbling Score ◽  
Muscle Area

Genetic parameters for three growth and five carcass traits were estimated for Charolais using a combination of carcass progeny test, purebred field performance and pedigree data. Heritabilities and genetic and residual correlations were derived from variance components for birth weight (BWT, n = 54 221), 205-d weaning weight (WT205, n = 31 384), postweaning gain (PWG, n = 19 403), hot carcass weight (HCW, n = 6958), average subcutaneous fat thickness (FAT, n = 6866), longissimus muscle area (REA, n = 6863), marbling score (MAR, n = 6903) and estimated carcass lean yield percentage (PLY, n = 6852) with an animal model (n = 78 728) and restricted maximum likelihood. Breed of dam and contemporary group appropriate to each trait were included as fixed effects in the model, whereas random effects included direct genetic for all traits, maternal genetic for BWT and WT205, and maternal permanent environmental for WT205. Carcass traits were adjusted to a constant harvest age of 425 d. Heritability estimates of 0.53, 0.22, and 0.21 were obtained for direct components of BWT, WT205, and PWG, respectively, and maternal heritabilities were 0.16 and 0.10 for BWT and WT205, respectively. Direct × maternal genetic correlations for BWT (-0.49) and WT205 (-0.35) were negative. Heritabilities for HCW, FAT, REA, MAR, and PLY were 0.33, 0.39, 0.43, 0.34, and 0.46, respectively. Genetic correlations among direct effects for growth traits were moderately positive and generally uncorrelated with maternal effects across traits. Lean and fat deposition in the carcass generally had negative, unfavorable genetic correlations, although improvement in lean yield and marbling score may not be strongly antagonistic. Genetic correlations of direct and maternal components of growth traits with carcass traits suggested that selection for increased growth rate would not be antagonistic to improvement in carcass yield or meat quality. Key words: Carcass, Charolais, correlation, genetic parameters, growth

Can we breed Merino sheep with softer, whiter, more photostable wool?

2010 ◽  
Vol 50 (12) ◽  
pp. 1089 ◽  
Author(s):  
S. Hatcher ◽  
P. I. Hynd ◽  
K. J. Thornberry ◽  
S. Gabb
Keyword(s):  
Genetic Parameters ◽  
Selection Index ◽  
Genetic Correlations ◽  
Genetic Selection ◽  
Phenotypic Selection ◽  
Quality Traits ◽  
Current Generation ◽  
Merino Sheep ◽  
Initial Cohort ◽  
Selection For

Genetic parameters (heritability, phenotypic and genetic correlations) were estimated for a range of visual and measured wool traits recorded from the 2008 shearing of the initial cohort of Merino progeny born into the Sheep CRC’s Information Nucleus Flock. The aim of this initial analysis was to determine the feasibility of selectively breeding Merino sheep for softer, whiter, more photostable wool and to quantify the likely impact on other wool production and quality traits. The estimates of heritability were high for handle and clean colour (0.86 and 0.70, respectively) and moderate for photostability (0.18), with some evidence of maternal effects for both handle and photostability. The phenotypic correlations between handle and clean colour and between handle and photostability were close to zero, indicating that achieving the ‘triple’ objective of softer, whiter, more photostable wool in the current generation through phenotypic selection alone would be difficult. There was evidence of an antagonistic relationship between handle and photostability (–0.36), such that genetic selection for softer wool will produce less photostable wool that will yellow on exposure to UV irradiation. However genetic selection for whiter wool is complementary to photostability and will result in whiter wool that is less likely to yellow. Genetic selection to improve handle, colour and photostability can be achieved with few detrimental effects on other visual and measured wool traits, particularly if they are included in an appropriate selection index.

scholarly journals 69 A new frame score system for Nelore cattle

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 47-47
Author(s):  
Roberto D Sainz ◽  
Nayanny Guimarães ◽  
Cláudio U Magnabosco ◽  
Fernando Lopes
Keyword(s):  
Body Composition ◽  
Beef Cattle ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Subcutaneous Fat ◽  
Heritability Estimate ◽  
Reproductive Traits ◽  
Carcass Weight ◽  
Muscle Area ◽  
Nelore Cattle

Abstract Frame score (FS) systems for beef cattle generally represent the relationships among growth, body composition, reproduction and mature size, in a simple and practical form. This study aimed to: 1) develop a FS system for Nelore cattle that is biologically sound, easy to interpret, and useful for producers; and 2) estimate the genetic parameters of the FS with productive and reproductive traits. An arbitrary scale (1 to 12) was devised so that each unit corresponds to 15 kg of carcass weight (1 @), as this is a common measure used for marketing beef cattle in Brazil. Therefore, ideal carcass weight, defined as having 6 mm of backfat, would be 18 @ (269 kg) and 15 @ (224 kg) for FS = 6 males and females, respectively. Data from 36,030 animals (22,405 males, 13,565 females) raised on pasture were obtained from participating herds of the National Association of Breeders and Researchers (ANCP). Genetic parameters were estimated in uni- and bicharacteristic analyses under an animal model, using the EM-REML algorithm (AIREMLF90) and Bayesian inference (GIBBS1F90). The heritability estimate for the new FS was 0.38, and its additive genetic correlations were 0.70, 0.72, 0.77, 0.33, -0.57, 0.27, and 0.28 with BW at 365 d, BW at 450 d, hip height, longissimus muscle area, subcutaneous fat thickness, scrotal circumference at 450 d, and age at first calving, respectively. The estimated heritability and genetic correlations indicate that there is enough additive genetic variability to allow for genetic response to selection. The estimates support the notion that larger frame animals are taller, heavier, leaner and later maturing, both in body composition as well as sexually. The new frame score may be a useful tool for genetic selection of animals that are best suited to their environment.

scholarly journals Meat quality and the calpain system of feedlot steers following a single generation of divergent selection for residual feed intake

2001 ◽  
Vol 41 (7) ◽  
pp. 1013 ◽  
Author(s):  
M. B. McDonagh ◽  
R. M. Herd ◽  
E. C. Richardson ◽  
V. H. Oddy ◽  
J. A. Archer ◽  
...  
Keyword(s):  
Feed Intake ◽  
Shear Force ◽  
High Efficiency ◽  
Subcutaneous Fat ◽  
Residual Feed Intake ◽  
Divergent Selection ◽  
Muscle Area ◽  
Eye Muscle ◽  
Single Generation ◽  
Selection For

Residual feed intake (RFI) is calculated as the difference between an animal’s actual feed intake and its expected feed intake based on its size and growth over a specified test period. Following a single generation of divergent selection for postweaning RFI, Angus steers and Angus × Hereford, Angus×Poll Hereford and Angus × Shorthorn crossbred steers born in 1996 and 1997 were fed in a feedlot. Cohorts of steers were slaughtered at the same age and had attained similar (P&gt;0.05) final liveweights: 467 kg for steers selected for low RFI (high efficiency; HE, n = 91) and 459 kg for steers selected for high RFI (low efficiency; LE, n = 98). The HE and LE steers had similar (P>0.05) carcass weight (247 and 244 kg), dressing percentage (53.1 and 53.2&percnt;) and eye-muscle area (58.9 and 60.3 cm 2 ). The HE steers had slightly less subcutaneous fat over the rib than the LE steers (9.2 v. 10.1 mm, P&lt;0.05), and there was a trend towards less fat over the rump of HE steers (11.5 v. 12.1 mm, P = 0.10). For meat samples taken from the M. longissimus dorsi (LD) there were no differences (P>0.05) between the HE and LE steers in content of intramuscular fat (5.4 and 5.3% fresh weight), marbling scores, meat colour and fat colour. There were also no differences (P>0.05) between HE and LE steers in shear force and compression values for samples of LD aged for 1 day (4.6 and 4.6 kg shear force, 1.45 and 1.44 kg compression), or for 14 days (3.8 and 3.5 kg, 1.36 and 1.32 kg). Myofibril fragmentation index (MFI) measures the breakdown of these structural elements which occurs as an initial step in the process of protein degradation and meat tenderisation. MFI was lower (i.e. less fragmentation; P<0.05) in LD samples from HE steers than from LE steers, both in samples aged for 1 day (67.7 v. 72.5 units) and in samples aged for 14 days (87.8 v. 91.1 units). The rate of decline in MFI between 1 and 14 days post slaughter was similar in the LD samples from both lines of steers. There were no differences (P>0.05) between HE and LE steers in the activity of m-calpain and &micro;-calpain in LD immediately after slaughter (HE steers: 1.9 and 2.3 units, LE steers: 1.8 and 2.1 units). The level of calpastatin in LD from the HE steers was 13% higher than in the LD from the LE steers (5.2 and 4.6 units respectively, P<0.05). Rate of myofibril fragmentation was positively correlated (P<0.01) with the ratios of both m-calpain and µ-calpain to calpastatin, but not (P>0.10) with levels of either calpain or calpastatin. A single generation of divergent selection for RFI produced differences in calpastatin and myofibril fragmentation that may, with on-going selection for low RFI, negatively affect meat tenderness.

scholarly journals Estimation of Genetic Parameters and Correlation between Yearling Ultrasound Measurements and Carcass Traits in Hanwoo Cattle

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1425
Author(s):  
Masoumeh Naserkheil ◽  
Deuk-Hwan Lee ◽  
Hong-Sik Kong ◽  
Jiyeon Seong ◽  
Hossein Mehrban
Keyword(s):  
Genetic Correlation ◽  
Genetic Parameters ◽  
Carcass Traits ◽  
Genetic Correlations ◽  
Backfat Thickness ◽  
Marbling Score ◽  
Muscle Area ◽  
Eye Muscle ◽  
Ultrasound Measurements ◽  
Heritability Estimates

Genetic parameters have a significant role in designing a breeding program and are required to evaluate economically important traits. The objective of this study was to estimate heritability and genetic correlation between yearling ultrasound measurements, such as backfat thickness (UBFT), eye muscle area (UEMA), intramuscular fat content (UIMF), and carcass traits, such as backfat thickness (BFT), carcass weight (CW), eye muscle area (EMA), marbling score (MS) at approximately 24 months of age, as well as yearling weight (YW) in Hanwoo bulls (15,796) and steers (5682). The (co) variance components were estimated using a multi-trait animal model. Moderate to high heritability estimates were obtained and were 0.42, 0.50, 0.56, and 0.59 for CW, EMA, BFT, and MS, respectively. Heritability estimates for yearling measurements of YW, UEMA, UBFT, and UIMF were 0.31, 0.32, 0.30, and 0.19, respectively. Favorable and strong genetic correlations were observed between UIMF and MS (0.78), UBFT and BFT (0.63), and UEMA and EMA (0.65). Moreover, the estimated genetic correlation between YW and CW was high (0.84) and relatively moderate between YW and EMA (0.43). These results suggest that genetic improvement can be achieved for carcass traits when using yearling ultrasound measurements as selection criteria in ongoing Hanwoo breeding programs.

Genetic relationships between live animal scan traits and carcass traits of Australian Angus bulls and heifers

2013 ◽  
Vol 53 (10) ◽  
pp. 1075
Author(s):  
Vinzent Börner ◽  
David J. Johnston ◽  
Hans-Ulrich Graser
Keyword(s):  
Genetic Gain ◽  
Genetic Parameters ◽  
Genetic Relationships ◽  
Carcass Traits ◽  
Genetic Correlations ◽  
Age Effect ◽  
Breeding Value ◽  
Muscle Area ◽  
Live Animal ◽  
Eye Muscle

Genetic parameters of four ultrasound live-scan traits and five carcass traits of Australian Angus cattle were examined with regard to sex and age of the scanned individuals. Live-scans were subdivided according to whether the observation was obtained from a bull or a heifer. In addition, two age subset (‘young’ and ‘old’) within sex were formed by k-means clustering around two centres within sex according to the age at scanning. REML estimates for heritabilities, genetic, residual and phenotypic correlations for each trait and trait combination were derived from a series of uni-, bi- and tri-variate analysis. Statistically significant age effects could be found for heritablities of scan intra-muscular fat content in heifers and scan fat depth at P8 site and scan rib fat depth in bulls, and for genetic correlations between the scan traits fat depth at P8 site, rib fat depth and eye muscle area. However, differences in heritablities between age sets within sex did not exceed 0.05, and genetic correlations between scan traits of ‘young’ and ‘old’ animals were at least 0.9. Differences between genetic correlations of abattoir carcass traits and ‘young’ and ‘old’ live-scan traits, respectively, were not significant due to high standard errors but up to 0.44. The larger of these differences were found for combinations of scan-traits and non-target carcass traits and not for combination of scan-traits and their actual carcass target traits. Thus, although some results suggest an age effect on the genetic parameters of scan traits, the extent of this effect is of limited impact on breeding value accuracy and genetic gain of scan traits. Furthermore, a possible age effect on correlations to economically important carcass traits need to be underpinned by more carcass traits observations in order to get unambiguous results allowing to draw consequences of scanning younger individuals for accuracy of breeding values and genetic gain in carcass traits.

Genetic parameters of carcass quality in Down cross sheep

1968 ◽  
Vol 10 (2) ◽  
pp. 183-191 ◽  
Author(s):  
J. C. Bowman ◽  
J. E. Marshall ◽  
J. S. Broadbent
Keyword(s):  
Genetic Variation ◽  
Genetic Parameters ◽  
Carcass Traits ◽  
Genetic Correlations ◽  
Carcass Quality ◽  
Correction Factors ◽  
Muscle Area ◽  
Eye Muscle ◽  
Additive Genetic Variation ◽  
Commercial Value

This report gives an account of the paternal half-sib analysis of carcass quality, based on commercial joint dissection, on Down cross sheep collected in the four years 1962–65 inclusive. It also includes a discussion of the multiplicative correction factors used, and the phenotypic and genetic correlations between all the traits, estimated from the pooled within-farm, within-year analysis. It shows that there is very little genetic variation for many of the characters but that the percentage leg, percentage best end, age at slaughter and eye-muscle area have much additive genetic variation remaining for worthwhile response to be expected from selection. These three carcass traits are also the most important characters in determining the commercial value and saleability of lamb. From the results obtained it is argued that there is still much genetic variation for fat development in sheep.

Genetic parameters of growth and carcass composition in crossbred lambs

1981 ◽  
Vol 32 (1) ◽  
pp. 1-7 ◽  
Author(s):  
B. T. Wolf ◽  
C. Smith ◽  
J. W. B. King ◽  
D. Nicholson
Keyword(s):  
Genetic Parameters ◽  
Growth Traits ◽  
Average Daily Gain ◽  
Genetic Correlations ◽  
Live Weight ◽  
Carcass Composition ◽  
Meat Production ◽  
Muscle Area ◽  
Eye Muscle ◽  
Nested Analysis

ABSTRACTData were available on crossbred meat lambs for 10 live-weight and growth traits (2585 lambs), 5 carcass traits (1884 lambs) and 10 dissection traits (944 lambs). These were the progeny born on an experimental farm over 5 years, from 102, 79 and 65 sires respectively for the three groups of traits. Genetic parameters were estimated from the sire components in a nested analysis of variance within breed of sire and year subclass, adjusting for sex, dam age, rearing type and other factors.The heritabilities of the live-weight and growth traits were all low, the highest being average daily gain to slaughter (0·10, s.e. 0·06), and none was statistically significant. The heritabilities of the traits of carcass composition were much higher: percentage lean (0·41, s.e. 0·13), percentage fat (0·37, s.e. 0·13) and percentage bone (0·16, s.e. 0·10). Intermediate values were found for most other traits: killing-out percentage (0·16, s.e. 0·07), fat depth (0·21, s.e. 0·11), eye-muscle area (0·14, s.e. 0·10) and lean/bone ratio (0·13, s.e. 0·09).Phenotypic and genetic correlations among the traits were also estimated. No major incompatibilities were found among the traits. The results are discussed in relation to the genetic improvement of lean meat production in sheep.

Genetic parameters for reproductive performance of breeding cows and carcass traits of fattening animals in Japanese Black (Wagyu) cattle

2004 ◽  
Vol 78 (2) ◽  
pp. 195-201 ◽  
Author(s):  
K. Oyama ◽  
T. Katsuta ◽  
K. Anada ◽  
F. Mukai
Keyword(s):  
Reproductive Performance ◽  
Genetic Parameters ◽  
Genetic Relationships ◽  
Carcass Traits ◽  
Genetic Correlations ◽  
Subcutaneous Fat ◽  
Reproductive Traits ◽  
Gestation Length ◽  
Marbling Score ◽  
Selection For

AbstractReproductive performance is receiving increased attention from beef cattle producers. There are concerns that intensive selection for carcass traits might reduce the reproductive performance of females. Genetic parameters among six carcass traits and, age at first calving (AFC), gestation length (GL), days open (DO) and calving interval (CI) under year-round artificial insemination were estimated. Reproductive traits were extracted from 174005 calving records of Japanese Black cows and were analysed with 31364 carcass records. The restricted maximum likelihood procedure under animal models was used to estimate the parameters. Heritabilities of AFC, GL, DO and CI were estimated to be 0.20, 0.40, 0.05 and 0.05, respectively, and those of carcass traits were higher, ranging from 0.38 to 0.56. Genetic correlations of CI with AFC and GL were 0.25 and 0.16, respectively, while no relationship was observed between AFC and GL. Correlations among carcass traits were generally favourable and a slightly negative estimate was obtained between subcutaneous fat thickness and marbling score. Genetic correlations for AFC were -0.27 with carcass weight and -0.24 with marbling score. In contrast, GL, DO and CI were genetically independent of carcass traits. Genetic relationships between reproductive and carcass traits were generally low, and therefore serious antagonism was not observed. The results suggested that selection for carcass traits would not compromise genetic progress in reproductive traits.

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