Carcass quality characteristics of swine selected for reduced backfat thickness and increased growth rate

1993 ◽  
Vol 73 (3) ◽  
pp. 483-494 ◽  
Author(s):  
R. L. Cliplef ◽  
R. M. McKay

Selection for reduced backfat thickness and increased growth rate in Yorkshire (eight generations) and Hampshire (seven generations) swine resulted not only in less backfat but carcasses which were longer with higher percentages of dissectible lean in the fresh hams. Selected carcasses also had a higher incidence of more severe loin lean-fat separation and subjectively perceived softness in the subcutaneous fat. Boar carcasses were longer and leaner with smaller loin eye areas compared with gilt carcasses. Key words: Swine, carcass quality, backfat, growth, selection

1992 ◽  
Vol 72 (2) ◽  
pp. 403-408 ◽  
Author(s):  
R. M. McKay

The impact of continued selection for reduced backfat thickness and improved growth rate on weight changes in Yorkshire and Hampshire sows, from breeding as gilts to weaning their second litter, was studied. Results suggest that some sow weight changes may have been influenced by selection pressure exerted. Key words: Sows, Canadian Yorkshire, Hampshire, liveweight change


1993 ◽  
Vol 73 (1) ◽  
pp. 201-206 ◽  
Author(s):  
R. L. Cliplef ◽  
R. M. McKay

Eight generations of Yorkshire swine and seven generations of Hampshire swine, involving a total of 2300 animals of which 1350 were selected for reduced backfat thickness and increased growth rate, had concurrent increases in visceral organ weights (heart, lungs, spleen, liver and kidney). Implications are that this could amount to 0.4 kg less weight per carcass. Key words: Pigs, organs, selection, Yorkshire, Hampshire


1993 ◽  
Vol 73 (2) ◽  
pp. 437-442 ◽  
Author(s):  
R. M. McKay

Index selection for reduced backfat thickness and increased postweaning growth rate resulted in increased preweaning death losses due either directly or indirectly to the sow in the Yorkshire and Hampshire breeds. This resulted in a reduced percentage of piglets weaned in the Yorkshire breed. Key words: Swine, selection index, preweaning period, mortality, survival


1990 ◽  
Vol 70 (3) ◽  
pp. 973-977 ◽  
Author(s):  
R. M. McKAY

Selection resulted in a decrease in probed backfat thickness and a negligible change in postweaning average daily gain. Realized heritabilities in the Yorkshire and Hampshire select lines were 0.41 ± 0.04 and 0.34 ± 0.18, respectively, for probed backfat thickness and 0.38 ± 0.43 and 0.65 ± 0.19, respectively, for postweaning average daily gain. Key words: Swine, selection differential, selection response, backfat, growth rate


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.


1993 ◽  
Vol 33 (6) ◽  
pp. 685 ◽  
Author(s):  
DL Hopkins ◽  
AHK Roberts

Fifty-six carcasses from grass-fed steers of 4 breed types, purchased for the Japanese market, were evaluated for quality and yield characteristics. The mean (� s.d.) carcass weight was 324 � 28.3 kg, and P8 fat depth 16.5 � 5.27 mm. Based on the Japanese grading system. 52 of the carcasses were considered acceptable for marbling, 54 for fat colour, and all carcasses for meat colour. The mean marbling, fat colour, and meat colour scores were 3.3, 3.3, and 3.5 respectively. The rank correlation between P8 fat depth and marbling score was 0.09, and a similar level of association was found between marbling score and fat depth measurements at other positions on the carcass. Measures of M. longissimus thoracis et lumborum (LD) area, using different techniques at the same rib, were significantly (P<0.001) correlated (5th rib, r = 0.87; 10th rib, r = 0.80); however, there was no association between LD area at the 5th and 10th ribs. Models were developed to predict the weight of saleable meat (SM) and fat trim (FT) based initially on hot standard carcass weight (HCW) and P8 fat depth as the independent variables. For all models HCW was the important predictor, with various measures of subcutaneous fat depth increasing the accuracy of estimates by a small amount. Fat depth measurements from the loin region reduced the error of prediction of SM more than fat depth measurements from the rump region, irrespective of the method used to measure fat depth. Replacing fat depth measures with the weight of trimmed fat significantly improved the accuracy of the predictions. The best model for predicting FT weight was based on the predictors HCW and fat depth at the 12th113th rib. Breed type was found to be not significant (P = 0.07) if included in a model with P8 fat depth and HCW. When breed type was included, P8 fat depth was no longer significant. When LD area at the 10th rib was included with HCW and P8 fat depth as a predictor of SM, P8 fat depth was no longer significant (P>0.05), but this was not the case when estimates of LD at the 5th rib were used. Regardless of this, estimates of LD area at both ribs showed themselves to be useful predictors of SM additional to HCW and P8 fat depth. Breed type was not a significant (P>0.05) contributor to the model based on the predictors HCW, P8 fat depth, and LD area at the 10th rib. If fat depth at the 10th rib was used with HCW and LD at the 10th rib instead of P8 fat depth, then more of the variation (R2 = 0.88 v. 0.85) in SM was explained and the error of the prediction was less (3.34 v. 3.75). Also, when fat depth at the 10th rib was used, the rib site used to estimate LD area was less important. The models showed that prediction of SM in heavyweight carcasses was marginally aided by using estimates of LD area.


1995 ◽  
Vol 1995 ◽  
pp. 90-90
Author(s):  
M. I. Mustafa ◽  
G. M. Webster

There is great variation in lamb carcass quality due to there being many breeds and crosses involved in lamb production. Breed of lamb appears to influence the pattern of development of the important carcass components, and thus the carcass quality, when comparison is made at equal weights. Plane of nutrition may also affect the growth rate, carcass composition and eating quality of lambs of the same genotype. It was planned to study the effect of both breed and diet on growth performance, carcass and meat quality characteristics by feeding two different diets to the lambs of two different breeds similarly managed from birth to slaughter.


1983 ◽  
Vol 36 (3) ◽  
pp. 389-397 ◽  
Author(s):  
J. D. Wood ◽  
O. P. Whelehan ◽  
M. Ellis ◽  
W. C. Smith ◽  
R. Laird

ABSTRACTThe effects of selection for low backfat thickness on tissue deposition in different body sites has been investigated in pigs. Eight castrated male and eight female pigs from each of the selection and control lines maintained at the University of Newcastle upon Tyne were used. One castrated male and one female from each line was killed at 15, 30, 45, 60, 75, 90, 105 and 120 kg live weight following ad libitum food consumption and fully dissected.There were only small effects of line on carcass composition, selected pigs having 120 g/kg more bone than controls at the mean side weight (P < 0·001) and 40 g/kg more lean (NS). At the same mean weight of subcutaneous fat, selected pigs had thinner backfat than controls (approximately 3 mm) over m. longissimus at the last rib and over the shoulder but not at the mid-rump or mid-back positions. There appears to have been a slight shift in the sites of fat deposition from above m. longissimus in the loin towards the mid-line and rump as a result of selection, even though mid-rump, C and K measurements were all included in the selection index. However, there was no difference between the lines in the weight distribution of subcutaneous fat between six regions and so these shifts must have been very localized. There was no difference between lines in the relationship between P2 fat thickness and proportion of lean in the side.The effects of selection on the sites of deposition within tissues other than subcutaneous fat were small. In particular there was no evidence that selection has caused relocation of body fat from subcutaneous to the other sites.


1976 ◽  
Vol 23 (1) ◽  
pp. 95-102 ◽  
Author(s):  
M. H. Fahmy ◽  
W. B. Holtmann ◽  
T. M. MacIntyre

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).


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