An evaluation of the use of ultrasound scanning to predict carcass traits in steers grain fed for the Japanese market

1998 ◽  
Vol 49 (1) ◽  
pp. 147 ◽  
Author(s):  
S. Baud ◽  
C. M. Wade ◽  
M. E. Goddard

The value of live-animal ultrasound scanning was assessed for steers grain-fed according to Japanese market specifications. Ultrasound scanning of the live animal for rump fat depth at the P8 site and for longissimus muscle area at feedlot entry did not accurately predict the ranking of individual steers on subcutaneous fat depth andlongissimus muscle area measured on the carcass at slaughter. When scanning was performed at the time of feedlot exit, up to 9 months later, the prediction of post-slaughter subcutaneous fat depth using scanned measurements made at the P8 site was of higher precision. Ultrasonic scanning to determine longissimus muscle area on feedlot exit was no better as a predictor of carcass longissimus muscle area than was that scanned at feedlot entry. The low correlations were probably due to differences in the sites of the scan (12th/13th rib interface) and longissimus muscle-area measurement (10th/11th rib interface) and to measurement errors in both the ultrasonic scan and the direct carcass measurements. Ultrasonic scan measurements may have been afiected by interference from deep fat cover on the steers. Genetic correlations were high but imprecisely estimated. Correlations between live-animal scanned measurements and the corresponding carcass measurements were high for steers from the same vendor property. Heritability estimates for the scanned measurements were in agreement with those from other studies.

Author(s):  
C J Duff ◽  
J H J van der Werf ◽  
P F Parnell ◽  
S A Clark

Abstract The improvement of carcass traits is an important breeding objective in beef cattle breeding programs. The most common way of selecting for improvement in carcass traits is via indirect selection using ultrasound scanning of selection candidates which are submitted to genetic evaluation programs. Two systems used to analyse ultrasound images to predict carcass traits are the Pie Medical Esaote Aquila (PIE) and Central Ultrasound Processing (CUP). This study compared the ability of the two systems to predict carcass traits for genetic evaluation in Australian Angus cattle. Genetic and phenotypic parameters were estimated using data from 1648 Angus steers which were ultrasound scanned twice with both systems, first at feedlot entry and then following 100 days in the feedlot. The traits interpreted from ultrasound scanning included eye muscle area (EMA), rib fat (RIB) rump fat (RUMP) and intramuscular fat (IMF). Abattoir carcass data were collected on all steers following the full feedlot feeding period of 285 days. For all ultrasound scan traits, CUP resulted in higher phenotypic and genetic variances compared to the PIE. For IMF, CUP had higher heritability at feedlot intake (0.51 for CUP compared to 0.37 for PIE) and after 100 days feeding (0.54 for CUP compared to 0.45 PIE). CUP predicted IMF also tended to have stronger correlations with the breeding objective traits of carcass IMF marbling traits, both genetically (ranging from 0.59 to 0.75 for CUP compared to 0.45 to 0.63 for PIE) and phenotypically (ranging from 0.27 to 0.43 for CUP compared to 0.19 to 0.28 for PIE). Ultrasound scan EMA were the only group of traits in which the heritabilities were higher for PIE (0.52 for PIE compared to 0.40 for CUP at feedlot intake and 0.46 for PIE compared to 0.43 for CUP at 100 days of feeding), however with similar relationships to the breeding objective carcass EMA observed. For subcutaneous fat traits of ultrasound RIB and RUMP, the heritabilites and genetic correlations to the related carcass traits were similar, with the exception being the higher heritability observed for CUP predicted RUMP at feedlot intake at 0.52 compared to 0.38 for PIE. The results from this study indicates that the CUP system, compared to PIE, provides an advantage for genetic evaluation of carcass traits in Angus cattle, particularly for the IMF and associated marbling traits.


2005 ◽  
Vol 85 (4) ◽  
pp. 463-473 ◽  
Author(s):  
R. Bergen ◽  
S. P. Miller ◽  
J. W. Wilton

Genetic correlations were examined among 10 live growth and ultrasound traits measured in yearling beef bulls (n = 2172) and four carcass traits measured in crossbred finished feedlot steers (n = 1031). Heritabilities ranged from 0.13 (bull ultrasound longissimus muscle width) to 0.83 (yearling bull hip height). Genetic correlations indicated that selecting yearling bulls for increased growth rate and hip height would lead to higher carcass weight, increased longissimus muscle area and reduced levels of carcass marbling in steers. Bull ultrasound fat depth was positively associated with both carcass fat depth and marbling score. Most ultrasound longissimus muscle size measurements in bulls were positively associated with each other and with carcass longissimus muscle area in steers, but the magnitude of the genetic correlation with carcass measurements depended on the bull longissimus muscle size trait in question. This suggests that longissimus muscle shape in bulls may be related to carcass weight, fat and muscle traits in steers. Results confirm that while ultrasound is a valuable tool for the genetic improvement of carcass traits in beef cattle, genetic correlations between live bull ultrasound and steer carcass traits less then unity suggest that selection would benefit from multiple trait evaluations in situations where reliable carcass data are available. Key words: Ultrasound, beef carcass, heritability, genetic correlation


2004 ◽  
Vol 84 (4) ◽  
pp. 589-597 ◽  
Author(s):  
D. H. Crews ◽  
Jr., M. Lowerison ◽  
N. Caron ◽  
R. A. Kemp

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


2013 ◽  
Vol 53 (10) ◽  
pp. 1075
Author(s):  
Vinzent Börner ◽  
David J. Johnston ◽  
Hans-Ulrich Graser

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.


2019 ◽  
Vol 99 (2) ◽  
pp. 296-306
Author(s):  
Daniel Duarte da Silveira ◽  
Lucas De Vargas ◽  
Rodrigo Junqueira Pereira ◽  
Gabriel Soares Campos ◽  
Ricardo Zambarda Vaz ◽  
...  

The aim of this study was to evaluate the genetic variability, genetic and phenotypic associations, and genetic gains of birth (BW), weaning (WW), and yearling (YW) weights, loin muscle area (LMA), backfat thickness (BF), rump fat thickness (RF), scores of body structure (BS), finishing precocity (FS), and muscling (MS) in Nelore cattle. Genetic parameters were obtained through Bayesian inference using BLUPF90 programs. All studied traits showed genetic variability, with heritability ranging from 0.29 to 0.47. In all studied ages, weights presented positive genetic correlations with LMA (ranging from 0.13 to 0.53), being generally stronger in comparison with the other carcass traits analyzed (BF and RF). Similarly, weights were higher genetic associated with BS (0.47–0.92) than with FS (0.18–0.62) and MS (0.22–0.65), respectively. The BF and RF showed positive and moderate genetic associations with FS and MS (0.31–0.36). Genetic trends were significant (P < 0.05) and favorable for WW, YW, and visual scores. Selection for increasing BW, WW, YW, and LMA will result in modest or no change in BF and RF (correlated response ranging from −0.04 to 0.07 mm per generation). In this population, carcass traits must be included in the selection indexes to obtain genetic gains in carcass quality, if desired.


2012 ◽  
Vol 41 (6) ◽  
pp. 1426-1432 ◽  
Author(s):  
Tiago Roque Pinheiro ◽  
Maria Eugênia Zerlotti Mercadante ◽  
Lucia Galvão de Albuquerque ◽  
Sarah Figueiredo Martins Bonilha ◽  
Fábio Morato Monteiro

2005 ◽  
Vol 62 (5) ◽  
pp. 423-426 ◽  
Author(s):  
Saulo da Luz e Silva ◽  
Evaldo Antonio Lencioni Titto ◽  
Paulo Roberto Leme ◽  
Luciane Silva Martello ◽  
Angélica Simone Cravo Pereira ◽  
...  

There is a paucity of information in the literature on body composition changes in Nellore cattle and its crosses, mainly on heifers and intact males. Ultrasound is a useful, low cost tool to easily obtain this information, with minimal animal stress. Effects of sex and days on feed on live weight (LW) and ultrasound Longissimus muscle area (ULMA) and subcutaneous fat thickness (UFAT) measurements were evaluated in F1 Piedmont <FONT FACE=Symbol>´</FONT> Nelore, 27 heifers (HF) and 27 intact males (IM). HF and IM had an initial LW of 256 ± 5.6 and 265 ± 5.6 kg, respectively, and were fed a diet containing 77% TDN for 131 days. LW, ULMA, and UFAT were evaluated at 28-d intervals. Interactions between sex and days on feed were found for all traits studied. LW increased linearly with days on feed, and IM had greater LW than HF throughout the trial. Mean initial ULMA was 55.8 and 55.5 cm² for HF and IM, respectively, and increased linearly until the end of the experiment (78.7 and 82.8 cm², respectively). IM showed higher ULMA than HF only in the last measurement. Initial UFAT averaged 0.04 and 0.4 mm for IM and HF, respectively, and increased linearly during the feeding period (2.4 and 4.3 mm, respectively). UFAT was higher n HF than in IM during the entire experimental period. IM showed faster growth rates and protein accretion than HF in the Longissimus muscle. HF showed faster subcutaneous fat accretion.


2013 ◽  
Vol 53 (4) ◽  
pp. 308 ◽  
Author(s):  
A. Estrada-Angulo ◽  
Y. S. Valdés ◽  
O. Carrillo-Muro ◽  
B. I. Castro-Perez ◽  
A. Barreras ◽  
...  

Forty Pelibuey × Kathdin lambs (35.5 ± 0.4 kg) were used in a 56-day feeding experiment to assess the effects of feeding different levels of chromium-enriched live yeast (Cr-YC) on growth performance, dietary energetics, carcass traits and visceral organ mass. The Cr-YC source contained 5.5 × 109 colony forming units (CFU) and 0.40 mg of Cr per gram. Treatments consisted of a dry rolled corn-based finishing diet supplemented with 0, 1, 2 or 3 g Cr-YC/lamb.day. Total daily dosages were: 5.5 × 109 CFU and 0.4 mg; 1.1 × 1010 CFU and 0.8 mg Cr, and 1.65 × 1010 CFU and 1.2 mg Cr for supplementation levels of 1, 2 or 3 g Cr-YC/lamb.day, respectively. There were no treatments effects on dry matter intake. As the level of Cr-YC supplementation increased, average daily gain, gain to feed and dietary net energy were linearly increased, and observed/expected dry matter intake was linearly decreased. Chromium-enriched live yeast supplementation increased empty bodyweight (EBW), gastrointestinal fill and full viscera weight, but did not influence organ weights as a proportion of EBW (g/kg EBW). Cr-YC level did not affect carcass length, backfat thickness, kidney, pelvic and heart fat or body wall thickness, but increased hot carcass weight and longissimus muscle area. In general, treatment effects on percentage yield of wholesale cuts (tissue weight as a percentage of cold carcass weight) were small. However, Cr-YC decreased percentage flank. Chromium-enriched yeast supplementation enhances growth rate, longissimus muscle area, and dietary energetic efficiency in finishing feedlot lambs.


1998 ◽  
Vol 49 (2) ◽  
pp. 285 ◽  
Author(s):  
S. Baud ◽  
C. M. Wade ◽  
M. E. Goddard

Carcass quality characteristics were measured on 511 steers of 4 breeds that were destined for the Japanese market. All steers had carcass measurements taken at the 10th/11th rib interface, while 103 steers had additional measurements made on the same characteristics at the 5th/6th rib interface. Australian marbling score, longissimus muscle area, intramuscular fat percentage, intramuscular water content, Japanese intermuscular fat thickness, Japanese subcutaneous fat thickness, Japanese rib thickness, and meat pH were measured in the study. These measurements allowed the phenotypic relationships between the different carcass quality traits measured at the 10th/11th rib interface to be calculated. Significant positive correlations were observed among measurements of carcass fatness, and significant negative correlations were observed between carcass fatness and carcass water content. Angus and Murray Grey cattle had higher levels of marbling and intramuscular fat than Hereford and Poll Hereford cattle The data enabled Australian, USDA, and Japanese marbling standards to be compared on the basis of intramuscular fat percentage determined by an ether extraction process. Differences between the same carcass characteristics taken at 5th/6th and 10/11th rib interfaces of the longissimus dorsi were estimated from the 103 steers measured at both sites. Correlations between the rib sites were high for marbling, intramuscular fat, and intramuscular water, but low for longissimus muscle area, intermuscular fat thickness, and pH.


1995 ◽  
Vol 46 (4) ◽  
pp. 703
Author(s):  
PA Kenney ◽  
ME Goddard ◽  
LP Thatcher

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.


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