A study of retail requirements and genetic parameters of carcass quality in polled dorset horn sheep

1972 ◽  
Vol 14 (2) ◽  
pp. 189-198 ◽  
Author(s):  
J. C. Bowman ◽  
C. R. C. Hendy
Keyword(s):  
Growth Rate ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Live Weight ◽  
Backfat Thickness ◽  
Unit Weight ◽  
Carcass Quality ◽  
Insufficient Data ◽  
Eye Muscle

SUMMARYData on growth rate and carcasses of pedigree Polled Dorset Horn castrated male lambs have been collected. The lambs were the half-sib progeny of 18 rams mated to groups of 20 ewes in 1968 and 1969. The lambs were slaughtered at between 35 and 45 kg live weight and when considered ‘fit’ on the basis of a handling appraisal. The whole carcasses were classified by a retail organization as either ‘accepted’ or ‘rejected’ and subsequently all carcasses were cut into commercial joints ready for sale. Analyses indicated that classification of carcasses was largely but not solely based on backfat thickness. Accepted carcasses were from older and heavier lambs which had larger eye-muscle areas. There was no difference in value per unit weight between accepted and rejected carcasses.Heritability for growth rate to 16 weeks of age was zero but for growth rate and age at slaughter was 0·26 ± 0·22 and 0·28 + μ 0·22 respectively. The heritability estimates for percentage best end, loin and backfat thickness were greater than 0·30. There were insufficient data to estimate genetic correlations accurately, but the estimates of pheno-typic correlations and heritabilities were very similar to those obtained in a previous study of carcasses of Down cross lambs.It is suggested that the method of choosing lambs for slaughter accounts for the large difference in the heritabilities for growth to 16 weeks and to slaughter. Selection to change backfat thickness would be effective and would probably result in a reduction in age at slaughter and an increase in growth rate to slaughter. Selection to change proportions of the carcass is not considered to be worthwhile.

Evaluation of performance at slaughter of twenty combinations of three-breed crosses of pigs

1976 ◽  
Vol 23 (1) ◽  
pp. 95-102 ◽  
Author(s):  
M. H. Fahmy ◽  
W. B. Holtmann ◽  
T. M. MacIntyre
Keyword(s):  
Growth Rate ◽  
Average Daily Gain ◽  
Live Weight ◽  
Backfat Thickness ◽  
Carcass Quality ◽  
Feed Conversion ◽  
Eye Muscle ◽  
Evaluation Of Performance ◽  
Breed Crosses ◽  
Daily Gain

SUMMARYTwo castrated male pigs from each of 620 litters were fed ad libitum to 90 kg market weight at three stations. The pigs represented 20 three-breed crosses produced by mating Yorkshire, Landrace, Lacombe, Hampshire and Duroc sires to Landrace-Yorkshire, Hampshire-Landrace, Large Black-Lacombe, Large Black-Landrace, Duroc-Lacombe and Duroc-Yorkshire dams. The data on feed conversion, average daily gain, age at slaughter, backfat thickness and area of loin eye muscle were analysed by least-squares.Within breed cross of dam, pigs sired by Hampshire were consistently superior in feed conversion, carcass quality and in 3 crosses out of 5 had the fastest growth rate during the fattening period. They were, however, the oldest at 90 kg live weight. Pigs sired by Duroc ranked second in carcass quality and growth rate, whereas those sired by Landrace had the slowest growth rate. The pigs produced by Hampshire-Landrace sows were superior in carcass quality but inferior in feed conversion and growth to those from sows of the other five crosses.In descending order, the four highest ranking crosses based on an index combining average daily gain, backfat thickness and feed efficiency were Hampshire × (Landrace-Yorkshire), Hampshire × (Duroc-Lacombe), Duroc × (Landrace-Yorkshire) and Hampshire × (Large Black-Landrace).

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.

Evaluation of three- and four-breed cross litters and pigs sired by purebred and crossbred boars

1977 ◽  
Vol 24 (2) ◽  
pp. 261-270 ◽  
Author(s):  
M. H. Fahmy ◽  
W. B. Holtmann
Keyword(s):  
Growth Rate ◽  
Average Daily Gain ◽  
Live Weight ◽  
Backfat Thickness ◽  
Significant Source ◽  
Carcass Quality ◽  
Breed Crosses ◽  
Daily Gain ◽  
Sire Breed

SUMMARYBoars from four pure breeds and three two-breed crosses were mated at two stations to sows from six two-breed crosses to produce three- and four-breed cross litters. Two types of three-breed crosses were produced either using purebred boars or by partial backcrossing using crossbred boars. From the 504 litters produced 965 male pigs were slaughtered at 90 kg live weight. The purebred boars produced litters which were 0·4 and 0·2 pigs larger and 0·14 and 1·14 kg heavier at birth and 21 days respectively than the crossbred boars. Differences between pigs sired by purebred and crossbred boars were negligible for growth rate and carcass quality. Little difference was also found between three- and four-breed cross pigs sired by crossbred boars (except for daily gain, P < 0·05). Breed of dam was a significant source of variation on all the traits except dressing-out percentage. Significant breed of sire effect was found on all the traits related to carcass quality but not on those related to growth. Breed of sire × breed of dam interaction was significant on backfat thickness, carcass lean yield percentage and average daily gain. The best crosses in carcass value were those of Duroc boars mated to Hampshire-Landrace and Landrace-Yorkshire sows, while those pigs with the fastest gain were from Landrace boars ×Duroc-Yorkshire sows and Duroc-Yorkshire boars × Large Black-Lacombe sows.

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.

The effects of different amounts of liquid skim-milk on pork pigs with particular reference to carcass quality

1965 ◽  
Vol 7 (2) ◽  
pp. 153-164 ◽  
Author(s):  
R. S. Barber ◽  
R. Braude ◽  
Zena D. Hosking ◽  
K. G. Mitchell
Keyword(s):  
Dry Matter ◽  
Skim Milk ◽  
Live Weight ◽  
Experimental Period ◽  
Carcass Quality ◽  
Eye Muscle ◽  
Caloric Value ◽  
Calculated Energy ◽  
Matter Basis

SUMMARY1. Seventy-two individually fed pigs on six treatments were used to determine the effects on performance and in particular on carcass quality of (a) giving quantities of liquid skim-milk (preserved with formalin) in excess of those normally recommended; (b) replacing meal by skim-milk in the ration on a calculated dry-matter basis (1 gal. skim-milk equivalent to 1 · 1 lb. meal) as compared with a calculated energy basis (1 gal. skim-milk equivalent to 1 · 3 lb. meal) and (c) giving skim-milk for only a part of the growing period instead of throughout. The experimental period continued from 9–10 weeks of age until slaughter at an average live-weight of 135 lb.2. Extensive carcass measurements were taken and in addition assessment of the carcasses was made by a representative of the County Quality Pork Association and by an expert pork butcher.3. Carcasses from pigs given an all-meal diet were comparable in all respects with those from pigs given skim-milk throughout up to a maximum of either 5¼ or 10½ pints per pig per day.4. Carcasses from pigs given the highest level of skim-milk (maximum of 15¾ pints per pig per day) were superior in many respects to those on any of the other treatments, but the possibility that this was due to their slower rate of growth rather than to the high level of milk per se, is discussed.5. Pigs given skim-milk as replacement of part of their meal allowance on a calculated dry matter basis grew significantly faster than those in which the replacement was made on a calculated energy basis or than those given an all-meal diet. The importance is stressed of ensuring that in assessing the value of skim-milk for pigs the caloric value of the rations being compared is similar. The need for experiments based on actual determinations of the caloric value of the rations used is also emphasised.6. While the performance of pigs given skim-milk up to 75 lb. live-weight only was similar to that of pigs given skim-milk throughout, evidence was obtained that the quality of their carcasses was slightly inferior.7. There was some suggestion that as the level of skim-milk in the diet increased an eye muscle of a rather paler colour was produced.

THE EFFECTS OF SEX AND AGE OF MALE AT CASTRATION ON GROWTH AND CARCASS QUALITY OF YORKSHIRE SWINE

1961 ◽  
Vol 41 (1) ◽  
pp. 30-39 ◽  
Author(s):  
L. A. Charette
Keyword(s):  
Growth Rate ◽  
Iodine Number ◽  
Feed Efficiency ◽  
Carcass Characteristics ◽  
Live Weight ◽  
Carcass Quality ◽  
Selection Of ◽  
Effect On Growth

The effects of sex and age of castration of males on growth rate, feed efficiency and carcass characteristics in bacon type swine were measured using 16 pigs each as gilts, entire boars, and boars castrated at birth, 6, 12, 16, and 20 weeks of age. Castration at 20 weeks was too late since some pigs reached 200 pounds live weight before that age. Boars consumed less feed daily than barrows and gilts, were thinner in loin fat, and yielded a higher percentage of shoulder than gilts. The carcasses of boars and gilts were longer, had less fat covering over the shoulder and back, a larger area of loin, and a higher iodine number than those castrated late. Acceptability tests showed that sex or age of castration did not affect the flavour, odour, or tenderness of the meat.Purebred breeders can delay castration for better selection of boars without any serious effect on growth, physical carcass characteristics, and feed requirements. Although the market discriminates against boars, it appears questionable whether castration is necessary when boars are slaughtered at 200 pounds before they reach the age of 150 days.

scholarly journals (Co)variance components and genetic parameters for growth rate and Kleiber ratio in fat-tailed Mehraban sheep

2013 ◽  
Vol 56 (1) ◽  
pp. 564-572 ◽  
Author(s):  
F. Ghafouri-Kesbi
Keyword(s):  
Growth Rate ◽  
Variance Components ◽  
Genetic Parameters ◽  
Average Daily Gain ◽  
Genetic Correlations ◽  
Phenotypic Variance ◽  
Genetic Progress ◽  
Kleiber Ratio ◽  
Derivative Free ◽  
Maternal Heritability

Abstract. The aim of the present study was to estimate (co)variance components and genetic parameters for average daily gain from birth to weaning (ADGa), weaning to 6 months (ADGb), weaning to 9 months (ADGc), 6 months to 9 months (ADGd) and corresponding Kleiber ratios (KRa, KRb, KRc and KRd) in Mehraban sheep. A derivative-free algorithm combined with a series of six univariate linear animal models was used to estimate phenotypic variance and its direct, maternal and residual components. In addition, bivariate analyses were done to estimate (co)variance components between traits. Estimates of direct heritability (h2) were 0.10, 0.11, 0.16, 0.09, 0.13, 0.13, 0.15 and 0.08 for ADGa, ADGb, ADGc, ADGd, KRa, KRb, KRc and KRd, respectively and indicate that in Mehraban sheep genes contribute very little to the variance of the growth rate and Kleiber ratio. Estimates of maternal heritability (m2) were 0.10, 0.08 and 0.05 for ADGa, KRa and KRb, respectively. Direct additive genetic correlations ranged from −0.32 (KRa-KRd) to 0.99 (ADGb-KRb) and phenotypic correlations ranged from −0.53 (ADGa- ADGd) to 0.99 (ADGa-KRa). Estimates of direct heritability and genetic correlations show that genetic improvement in efficiency of feed utilization through selection programmes is possible, though it would generate a relatively slow genetic progress.

Genetic parameters for daily live-weight gain, live fleshiness and bone thinness in station-tested Piemontese young bulls

2001 ◽  
Vol 72 (3) ◽  
pp. 449-456 ◽  
Author(s):  
A. Albera ◽  
R. Mantovani ◽  
G. Bittante ◽  
A. F. Groen ◽  
P. Carnier
Keyword(s):  
Weight Gain ◽  
Genetic Parameters ◽  
Growth Traits ◽  
Genetic Correlations ◽  
Live Weight ◽  
Adaptation Period ◽  
Production Traits ◽  
Multiple Trait ◽  
Live Weight Gain ◽  
Total Gain

AbstractEstimates of genetic parameters for beef production traits were obtained for Piemontese cattle. Data were from 988 young bulls station-tested from 1989 till 1998. Bulls entered the station at 6 to 8 weeks of age and, after an adaptation period of 3 months, were tested for growth, live fleshiness and bone thinness. Length of test was 196 days. Growth traits considered were gain at farm, gain during the adaptation period, gain on test and total gain at the station. Six different fleshiness traits and bone thinness were scored on live animals at the end of the test using a linear system. Live evaluations of fleshiness were adjusted for the weight at scoring in order to provide an assessment of conformation independent of body size. Genetic parameters were estimated using animal models. Heritability of live-weight gain ranged from 0·20 in the adaptation period to 0·60 for total gain at the station. Genetic correlations between gains at station in different periods were high (from 0·63 to 0·97). Residual correlation between gain during the adaptation period and gain during test was negative, probably due to the occurrence of compensatory growth of the animals.Live fleshiness traits and bone thinness were of moderate to high heritability (from 0·34 to 0·55) and highly correlated indicating that heavy muscled bulls also have thin bones. Accuracy of breeding values and therefore response to selection were improved by multiple trait analysis of the live fleshiness traits and bone thinness. Overall weight gain at the station had a moderate negative genetic correlation with all live fleshiness traits and bone thinness (from –0·11 to –0·39).

Effects of castration on growth rate, feed conversion efficiency and carcass quality in Damascus goats

1977 ◽  
Vol 24 (3) ◽  
pp. 387-391 ◽  
Author(s):  
A. Louca ◽  
S. Economides ◽  
J. Hancock
Keyword(s):  
Growth Rate ◽  
Sexual Activity ◽  
Conversion Efficiency ◽  
Live Weight ◽  
Carcass Quality ◽  
Feed Conversion ◽  
Intact Male ◽  
Goat Meat ◽  
Feed Conversion Efficiency

SUMMARYOne hundred and forty-two kids of the Damascus breed of goat were used over a 10½-mo period to study the effects of early castration (at 7 days of age) on growth, feed conversion efficiency and carcass quality and late castration (at 7½ mo of age) on the presence or absence of taint in goat meat.Intact male kids grew faster and used feed more efficiently than castrates until they were about 9 mo old (56 kg live weight). There- after intact kids exhibited strong sexual activity and as a result their growth ceased completely whereas castrates continued growing. Early castrates produced fatter carcasses than those of intact kids. Castration of male kids at the age of about 7½ mo (44 kg live weight) was not successful in this trial and the kids performed very poorly. A taint of varying intensity was present in the meat of intact goats but not in that from any of the early or late castrates.

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