GENETIC AND PHENOTYPIC PARAMETERS OF CARCASS TRAITS IN RAM LAMBS REARED ARTIFICIALLY IN A CONTROLLED ENVIRONMENT

1986 ◽  
Vol 66 (4) ◽  
pp. 905-914 ◽  
Author(s):  
J. N. B. SHRESTHA ◽  
A. FORTIN ◽  
D. P. HEANEY

Genetic and phenotypic relationships among carcass traits were calculated for 654 ram lambs from 210 sires of three synthetic strains developed at the Animal Research Centre. Lambs were housed indoors in a controlled environment on expanded metal floors and reared artificially with milk replacer and solid diets. Paternal half-sib estimates of heritability at 36-kg body weight and 116 of age were moderate to high ranging from 0.38 to 0.67 for shoulder and leg (trimmed and lean), total trimmed retail cuts, total lean, chilled carcass weight and lean weight per day (P < 0.01). Estimates of phenotypic and genetic correlations between the above traits showed a significantly favorable relationship indicating their usefulness as criteria in selection for meatiness. Heritability estimates for front, back and total in rough retail cuts, trimmed loin cuts, lean in rack and loin, kidney fat weight and dressing percentage ranged from −0.19 to 0.27 (P > 0.05). Estimates involving loin, rack, front, back, total retail cuts, kidney fat wt, dressing percentage and chilled carcass weight per day showed lower and nonsignificant relationships with total trimmed retail cuts or total lean. Key words: Sheep, heritability, genetic and phenotypic correlations, lamb carcass traits

2019 ◽  
Vol 97 (11) ◽  
pp. 4405-4417 ◽  
Author(s):  
David N Kelly ◽  
Craig Murphy ◽  
Roy D Sleator ◽  
Michelle M Judge ◽  
Stephen B Conroy ◽  
...  

Abstract Some definitions of feed efficiency such as residual energy intake (REI) and residual gain (RG) may not truly reflect production efficiency. The energy sinks used in the derivation of the traits include metabolic live-weight; producers finishing cattle for slaughter are, however, paid on the basis of carcass weight, as opposed to live-weight. The objective of the present study was to explore alternative definitions of REI and RG which are more reflective of production efficiency, and quantify their relationship with performance, ultrasound, and carcass traits across multiple breeds and sexes of cattle. Feed intake and live-weight records were available on 5,172 growing animals, 2,187 of which also had information relating to carcass traits; all animals were fed a concentrate-based diet representative of a feedlot diet. Animal linear mixed models were used to estimate (co)variance components. Heritability estimates for all derived REI traits varied from 0.36 (REICWF; REI using carcass weight and carcass fat as energy sinks) to 0.50 (traditional REI derived with the energy sinks of both live-weight and ADG). The heritability for the RG traits varied from 0.24 to 0.34. Phenotypic correlations among all definitions of the REI traits ranged from 0.90 (REI with REICWF) to 0.99 (traditional REI with REI using metabolic preslaughter live-weight and ADG). All were different (P < 0.001) from one suggesting reranking of animals when using different definitions of REI to identify efficient cattle. The derived RG traits were either weakly or not correlated (P > 0.05) with the ultrasound and carcass traits. Genetic correlations between the REI traits with carcass weight, dressing difference (i.e., live-weight immediately preslaughter minus carcass weight) and dressing percentage (i.e., carcass weight divided by live-weight immediately preslaughter) implies that selection on any of the REI traits will increase carcass weight, lower the dressing difference and increase dressing percentage. Selection on REICW (REI using carcass weight as an energy sink), as opposed to traditional REI, should increase the carcass weight 2.2 times slower but reduce the dressing difference 4.3 times faster. While traditionally defined REI is informative from a research perspective, the ability to convert energy into live-weight gain does not necessarily equate to carcass gain, and as such, traits such as REICW and REICWF provide a better description of production efficiency for feedlot cattle.


1985 ◽  
Vol 65 (1) ◽  
pp. 37-49 ◽  
Author(s):  
J. N. B. SHRESTHA ◽  
D. P. HEANEY

This study involved body weights of 6078 lambs from 525 sires of two synthetic dam strains developed at the Animal Research Centre with 50% Finnish Landrace background. Breeding was practiced in flocks A and B for lambing at 4-mo intervals under an 8-mo breeding cycle. Lambs were housed indoors in a controlled environment on expanded metal floors in windowless barns, reared artificially with milk replacer and solid diet from birth to weaning at 21 days of age. Thereafter, all lambs were fed solid diet to 70 days of age. Paternal half-sib estimates of heritability for lamb weights at birth, weaning, 49 and 70 days of age were 0.25–0.26. Heritability estimates in the two synthetic dam strains were in close agreement (P > 0.05). Genetic and phenotypic parameter estimates did not demonstrate any significant linear trends across lambing periods. The moderate levels of heritability estimates for lambs reared artificially under a controlled environment suggest that genetic response to selection could be enhanced by selecting lambs independent of potential maternal effects and competition among litter mates for a fixed quantity of milk. Estimates of genetic and phenotypic correlations among various lamb weights ranged from 0.60 to 1.00, and from 0.51 to 0.93, respectively. Lamb weights having closer proximity in time showed higher correlations. Moderate to high genetic correlations between body weight of lambs at different ages indicated that selection for weight at one age should cause no adverse effects on body weight at other ages. Key words: Sheep, artificial rearing, lamb weights, heritability, genetic and phenotypic correlations


2012 ◽  
Vol 28 (4) ◽  
pp. 855-861 ◽  
Author(s):  
D.M. Ogah

In this study, canonical correlation analysis was applied to estimate the relationship between body measurements and carcass traits of 28 male cross bred rabbits of about 12 weeks of age, reared under semi intensive system. Four body measurements, pre-slaughter weight (PSW) , body length (BL), chest circumference (CC), and ear length (EL) as predictor variable while dressing percentage ( DP) , hot carcass weight (HCW) and cold carcass weight (CCW) as criterion variables. Pre-slaughter weight and body length had significant (P<0.001) simple correlation coefficients with the carcass traits except for dressing percentage. The three canonical variate pairs ranged between .99 to .42 and only the first pair was significant (P<0.001). From the analysis pre-slaughter weight and body length can be regarded as the main factors as live measurement traits, while dressing percentage did not have pronounced effect on the emerged criterion variables.


1984 ◽  
Vol 39 (3) ◽  
pp. 433-440 ◽  
Author(s):  
G. J. Lee

ABSTRACTA total of 219 lambs of the Welsh Mountain (W) and Scottish Blackface (B) breeds, and six types of crossbred with varying proportions of the two breeds from a cyclical crossbreeding experiment, were slaughtered in six groups at fortnightly intervals from 6 to 8 months of age. Each group had balanced numbers of each genotype and each sex. Genotype differences and effects of heterosis were estimated. Fat grades were assessed by farm staff before slaughter and Meat and Livestock Commission fat and conformation scores and external linear hindquarter measurements of each carcass were recorded.At the same age, W carcasses were lighter (W: B = 0·86, W = 11·7 kg, B = 13·4 kg) but were more mature and had more kidney fat (W: B = 1·73) and higher fat and conformation scores especially in the loin region, but relatively shorter, thinner legs. At the same degree of maturity (carcass weight/estimated mature carcass weight), the Welsh carcasses had more kidney fat but the difference in leg measurements was reduced, and the differences for fat and conformation scores disappeared. When compared at the same grade, the Welsh lambs were 2 kg lighter and had higher conformation scores suggesting comparative undergrading, especially by the farm assessors. Results for crossbred lambs were as predicted from their breed composition and there was no evidence of heterosis.The results suggest that at the same estimated carcass fatness, the Blackface has the potential to produce a heavier carcass but is later maturing, taking approx. 12 days longer to reach this degree of fatness.


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


1967 ◽  
Vol 9 (1) ◽  
pp. 115-119 ◽  
Author(s):  
D. Levi ◽  
M. Soller ◽  
A. Shilo

Data were collected during 1961–2 on the live-weight, age and warm carcass weights of 83 lots of Israel-Friesian bull calves, 525 animals in all, the offspring of 26 sires. For varying numbers of these animals weight of various non-saleable fat components, including ruminal fat, kidney fat, inguinal fat and scapular fat were also obtained. Ruminal fat alone and ruminal fat plus kidney fat were found to be highly correlated with total non-saleable fat (r = 0·84 and 0·94, respectively). Heritability of dressing percentage was 0·20, of live-weight rate-of-gain 0·92, and of carcass rate-ofgain 0·49. The genetic correlation between live-weight and carcass weight was 0·7. Between-lot correlations indicated that increased rate-of-gain achieved through management will be accompanied by decreased dressing percentage and increased non-saleable fat content.


Author(s):  
Eser Kemal Gurcan ◽  
Dogan Narinc ◽  
Selcuk Kaplan

This study aimed to determine the phenotypic values of the slaughter and carcass traits in the flocks of quails obtained when a flock of parent quails were at 12, 16, and 20 weeks of age and to estimate the heritabilities and the genetic correlations for these traits. For this purpose, a total of 1,346 Japanese quails were slaughtered at 8 weeks of age, and their slaughter weights as well as carcass, breast, leg, and abdominal fat weights and ratios were determined. Differences in all traits were detected between female and male quails (P<0.05). The averages of many important traits, primarily slaughter weight, carcass weight, and breast weight, increased with the increase in the breeder age. On the contrary, the carcass yield decreased (P<0.05). There were no significant variations in the phenotypic and genetic variances for the slaughter and carcass traits in the flocks obtained when the breeder flock was at different ages. The heritabilities for slaughter weight, carcass weight, and abdominal fat weight were estimated to be moderate, and the genetic correlations among them were estimated to be positive and high. In conclusion, it is possible to state that positive results might be obtained by using the carcass ratio as the criterion for selection in quails. Besides, the breeder age was discovered to have had no significant effect on the genetic parameter estimations.


1983 ◽  
Vol 63 (4) ◽  
pp. 791-802 ◽  
Author(s):  
G. W. RAHNEFELD ◽  
H. T. FREDEEN ◽  
G. M. WEISS ◽  
J. A. NEWMAN ◽  
J. E. LAWSON

Carcass characteristics of 3673 steers and heifers born over a 6-yr period 1973–1978 at Brandon, Manitoba (farm conditions) and Manyberries, Alberta (range conditions) were compared. Calves weaned at Manyberries were fed and evaluated at Lacombe. The progeny were out of 10 specific F1 crosses of dams mated to bulls of the Charolais (C), Simmental (S), Limousin (L) and Chianina (Chi) breeds. Dam crosses included the Hereford × Angus (HA) and crosses sired by C, S and L sires out of H, A and Shorthorn (N) dams. Breed of sire of dam effects indicated that progeny from S cross cows generally had the heaviest carcasses S = C > L, the greatest carcass weight per day of age S = C > L, the highest percentage of dissected bone of the round S > C > L and rib S > C = L, the highest proportions of brisket S > L > C and flank S > L = C, and carried more kidney fat (percent liveweight) S > C = L and average rib fat S > C = L. Progeny from Limousin and Charolais cross cows had the highest dressing percentage [Formula: see text] and rib eye area/100 kg carcass wieght L > C > S while those from Limousin cross cows had the highest proportion of long loin and the combined lean cuts (rib, round and long loin) a higher percentage of dissected lean in the round L > C > S and the highest lean-to-bone ratio L > C > S. Progeny from dams of Shorthorn breeding generally had the heaviest carcasses, the greatest carcass weight per day of age, the highest percentage kidney fat and at Brandon the greatest proportions of plate and brisket. Hereford cross dams consistently produced progeny with the highest percentage head H = A > N, hide [Formula: see text], feet H > A = N, percentage bone in the long loin [Formula: see text], round [Formula: see text], and rib [Formula: see text], and the highest percentage lean in the long loin H > N (Brandon) and chuck H > N (Brandon). The progeny from Angus cross dams carried the greatest average rib fat [Formula: see text], had the greatest rib eye area/100 kg carcass weight [Formula: see text], the highest percentage lean in the round [Formula: see text], and the highest lean to bone ratio A > H = N. Key words: Cattle, breeds, carcass, cuts, composition


1983 ◽  
Vol 23 (122) ◽  
pp. 235 ◽  
Author(s):  
JR Wythes ◽  
MJ Brown ◽  
WR Shorthose ◽  
MR Clarke

In two experiments, we examined the effects on liveweight, carcass traits and muscle properties of (a) sending cattle to the abattoir either direct from a farm or via a saleyard, and (b) different curfew and sale procedures at a saleyard. During the 12 h curfew and 10 h sale periods, cattle were held with or without water, but always denied feed. In experiment 1, after a journey of 1320 km, 252 bullocks (mean liveweight 558 kg) were subjected to one of seven treatments. The groups transported direct to the abattoir were (1) denied water between arrival and slaughter (26 h), (2) offered water for 26 h, or (3) offered water and feed for 50 h and then water alone for 24 h. Those sent to the saleyard were given access to water (4) at all times, (5) only during the curfew and sale periods, (6) only before the curfew began, or (7) were denied water until after the sale, when all groups were offered water for 36 h until slaughter. Among the bullocks sent direct to the abattoir, the group with water for 26 h until slaughter had heavier (P< 0.0 1 ) carcasses than those denied water (331 kg vs 312 kg) and also a greater (P < 0.0 1) muscle water content, while the carcasses of the group slaughtered 2 d later were intermediate for both. Whether dressing percentages were calculated on liveweights at the start or end of the simulated sale for the four saleyard groups, the differences in mean dressing percentages between groups offered water (0.7 and 0.3 percentage units) were less than the differences between the means of the groups denied water (3.7 and 3.5 units). The increases in dressing percentage during the sale for groups with water (0.7 and 0.3 units) were less than those for the groups denied water (1.5 and 1.7 units). Differences in mean liveweights and mean muscle water contents between groups followed the same trends. Mean carcass weights did not differ significantly between saleyard groups (318-323 kg). In experiment 2, after a journey of 90 km, 152 cows (mean liveweight 323 kg) were subjected to one of four treatments. The group going direct to the abattoir was offered water for 4.5 h, fasted for 16 h and then slaughtered. For the other three groups, the saleyard treatments 4,6, or 7 of experiment 1were imposed, followed by 21 h on water and a 16 h pre-slaughter fast. Trends in dressing percentage and liveweight were similar to those recorded in experiment 1. Mean carcass weight varied (P<0. 05) between groups and tended to increase with muscle water content. Method of sale was important because it affected the time from mustering to slaughter, and thus, carcass weight. At saleyards, the practice of giving cattle continuous access to water reduced significantly the variation in liveweight, dressing percentage and muscle water content between groups with similar initial liveweights. This practice at abattoirs avoided dehydration of carcass tissues at slaughter


2004 ◽  
Vol 84 (4) ◽  
pp. 599-609 ◽  
Author(s):  
J. A. Minick ◽  
M. E. Dikeman ◽  
E. J. Pollak ◽  
D. E. Wilson

Heritabilities and correlations of Warner-Bratzler shear force (WBSF), marbling score (MS), hot carcass weight (HCW),12–13th rib-fat (FAT), and ribeye area (REA) were calculated from 3360 Angus-, Charolais-, Hereford-, and Simmental-sired cattle in the C attleman’s Beef Board Carcass Merit Project. The heritabilities (± SE) for WBSF, MS, HCW, FAT, and REA were 0.34 ± 0.25, 0.43 ± 0.28, 0.73 ± 0.35, 0.16 ± 0.19, and 0.56 ± 0.31 in Angus; 0.43 ± 0.22, 0.30 ± 0.18, 0.21 ± 0.16, 0.35 ± 0.20, and 0.23 ± 0.16 in Charolais; 0.12 ± 0.11, 0.55 ± 0.22, 0.20 ± 0.14, 0.25 ± 0.15 and 0.34 ± 0.17 in Hereford; and 0.16 ± 0.14, 0.44 ± 0.20, 0.45 ± 0.20, 0.23 ± 0.16, and 0.30 ± 0.18 in Simmental. The genetic correlations, averaged across analysis type, for WBSF-MS, WBSF-HCW, WBSF-FAT, WBSF-REA, MS-HCW, MS-FAT, MS-REA, HCW-FAT, HCW-REA, and FAT-REA were -0.17, 0.32, -0.23, 0.30, 0.10, -0.17, 0.39, -0.15, 0.68, and -0.86 in Angus; -0.42, 0.77, 0.52, -0.05, -0.44, -0.22, -0.19, 0.66, -0.05, and -0.24 in Charolais; -0.43, -0.04, -0.33, 0.09, 0.08, 0.79, -0.14, -0.26, 0.50, and -0.38 in Hereford; and 0.55, 0.08, 0.62, -0.08, 0.30, 0.61, -0.14, 0.06, 0.65, and -0.48 in Simmental. Key words: Beef cattle, genetic parameters, carcass quality, tenderness


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