Genotype and age effects on sheep meat production. 3. Meat quality

2007 ◽  
Vol 47 (10) ◽  
pp. 1155 ◽  
Author(s):  
D. L. Hopkins ◽  
D. F. Stanley ◽  
L. C. Martin ◽  
E. S. Toohey ◽  
A. R. Gilmour
Keyword(s):  
Meat Quality ◽  
Significant Interaction ◽  
Shear Force ◽  
Breeding Value ◽  
Meat Production ◽  
Post Mortem ◽  
Fat Percentage ◽  
Sheep Meat ◽  
Semimembranosus Muscle ◽  
Sire Breed

A 5 × 4 factorial experiment was designed in which lambs representing five genotypes were slaughtered at four ages (110, 236, 412 and 662 days of age or 4, 8, 14 and 22 months of age). The genotypes represented were Poll Dorsetgrowth × Border Leicester Merino (PDg × BLM), Poll Dorsetgrowth × Merino (PDg × M), Poll Dorsetmuscling × Merino (PDm × M), Merino × Merino (M × M) and Border Leicester × Merino (BL × M). In total, 595 animals were slaughtered and carcass traits, composition and meat quality measured. As the animals grew older, intramuscular fat percentage (IMF) increased in the longissimus (LL) muscle and as the proportion of Border Leicester parentage increased so did the levels of IMF. There was a significant sire breed effect on LL pH at 24 hours after slaughter (pH24), with Merino-sired animals having a higher pH24 than both Poll Dorset and BL-sired animals. A significant dam breed effect was found for pH24 of the semitendinosus (ST) muscle, with lambs born to Merino ewes having a higher pH than those born to BLM ewes. A significant effect of sire estimated breeding value (EBV) for yearling muscling (YEMD) on LL pH was detected indicating an increase in pH as the sire EBV for muscling increased. There was a significant Merino effect for ultimate pH of the ST, with Merino-sired animals having a higher ultimate pH than both Poll Dorset and Border Leicester-sired animals. Sucker lambs had a significantly lower ST pH than older animals. As animal age at slaughter increased, the LL became darker based on L* values. There was a significant increase in a* values as animals became older, with 14 and 22-month-old animals having redder muscle. As LL pH and YEMD EBV increased, a* values decreased. There was a significant interaction between animal age and post mortem aging time such that sucker lambs (4 months old) produced LL with the lowest shear force after 5 days of aging and exhibited the greatest decline in shear force with aging. There was a significant increase in semimembranosus muscle shear force for PDm-sired animals (mean ± s.e., 66.5 ± 1.99 Newtons) compared with other genotypes at 61.4 ± 1.28 Newtons, but this could not be attributed to YEMD.

Genotype and age effects on sheep meat production. 1. Production and growth

2007 ◽  
Vol 47 (10) ◽  
pp. 1119 ◽  
Author(s):  
D. L. Hopkins ◽  
D. F. Stanley ◽  
L. C. Martin ◽  
A. R. Gilmour
Keyword(s):  
Significant Interaction ◽  
Meat Production ◽  
Age Group ◽  
Weaning Weight ◽  
Genotype Effect ◽  
Ewe Lambs ◽  
Sheep Meat ◽  
Fleece Weight ◽  
Estimated Breeding Values ◽  
Sire Breed

The growth, wool production and teeth eruption of animals from five genotypes [Poll Dorsetgrowth (PD) × Border Leicester × Merino (BLM); PDg × Merino (M); Poll Dorsetmuscling (PDm) × M; M × M; BL × M] were evaluated over the age span of 4 to 22 months of age. In total, 16 sires were used to generate the animals and these were selected for growth based on estimated breeding values (EBVs), apart from one group (PDm) which was selected for muscling based on EBVs. In total, 595 animals were slaughtered at 4, 8, 14 or 22 months of age. The birthweight of lambs born to BLM ewes was 0.6 kg heavier (P < 0.001) than those born to Merino ewes, and wether lambs were 0.2 kg heavier than ewe lambs (P < 0.001). The yearling weight (YWT) EBV had no effect on birthweight. There were significant (P < 0.001) differences between genotypes for predicted weaning weight at 4 months of age, with a range of 10.6 kg among the groups. The PDg × BLM were the heaviest (37.8 ± 0.7 kg) and the Merino the lightest (27.3 ± 0.8 kg). Wether lambs were 2.0 kg heavier (P < 0.001) than ewe lambs at weaning. The YWT EBV had no effect on weaning weight. There was a significant (P < 0.001) interaction between the age at slaughter and genotype for final liveweight of each age group. The PDg × BLM were the heaviest at each age and the Merinos the lightest, and for the oldest animals, the BLM were significantly (P < 0.05) heavier than PDm × M, whereas at younger ages this was not the case. The significant interaction (P < 0.001) between sex and age at slaughter reflected the increasing difference in liveweight between the sexes as age at slaughter increased. There was also a significant (P < 0.05) interaction between the YWT EBV and age at slaughter. The overall coefficients were –0.01, 0.14, 0.34 and 0.65 for slaughter ages 4, 8, 14 and 22 months, respectively, indicating that in young animals there was no effect of sire YWT EBV on liveweight, but as the animals aged there was an increasing effect such that progeny of sires with high sire YWT EBV were heavier. This effect was evident within all genotypes. There was a sire breed effect on fleece weight and total wool weight (P < 0.001) with Merino-sired hoggets producing 0.4 kg more wool than Border Leicester-sired hoggets and 1.5 kg more than Poll Dorset-sired hoggets. There was a weak genotype effect on time to erupt the first permanent incisor, which if modelled as a proportion of Border Leicester (0, 1/4, 1/2) was significant (–34 ± 12 days, P < 0.05), Border Leicester earlier than not Border Leicester. Ewe lambs took 9 days longer (P < 0.05) to erupt their first permanent incisor compared with wether lambs.

Variability of the IGF2 locus in the Suino Nero Lucano pig population and its effects on meat quality

2018 ◽  
Vol 58 (11) ◽  
pp. 1976 ◽  
Author(s):  
Amalia Simonetti ◽  
Andrea Rando ◽  
Paola Di Gregorio ◽  
Carmelisa Valluzzi ◽  
Annamaria Perna ◽  
...  
Keyword(s):  
Meat Quality ◽  
Shear Force ◽  
Quality Characteristics ◽  
Porcine Insulin ◽  
Drip Loss ◽  
Fat Percentage ◽  
Promoter Regions ◽  
Igf2 Gene ◽  
Longissimus Lumborum ◽  
L Value

The aim of this study was to analyse the polymorphisms in the two promoter regions, P1 and P2, of the porcine Insulin-like Growth Factor 2 (IGF2) gene and to investigate the effect of IGF2 genotypes on meat quality traits in the Italian autochthonous Suino Nero Lucano pig. Three polymorphic sites were analysed and only two of the eight potential haplotypes were observed in the Suino Nero Lucano pig population: A haplotype (–366A – –225G – –182C), and B haplotype (–366G – –225C – –182T). Muscle mass and meat quality characteristics were analysed in 30 castrated pigs (10 for each of the three IGF2 genotypes: A/A, A/B, and B/B). According to the results, B/B animals, at the same carcass weight, showed the highest Longissimus lumborum and Psoas weight (P < 0.05), whereas A/A animals showed a higher intramuscular fat percentage and lower Warner–Bratzler shear force, drip loss, and polyunsaturated fatty acids content. Meat from B/B animals showed also a higher L* value and myoglobin and deoxymyoglobin percentage compared with meat from A/A ones (P < 0.05).

scholarly journals The effect of extended post-mortem ageing on the Warner–Brazler shear force of longissimus thoracis from beef heifers from two sire breeds, slaughtered at 20 or 25 mo of age

2020 ◽  
Author(s):  
A.P. Moloney ◽  
B. Picard ◽  
L. Moran
Keyword(s):  
Chemical Analysis ◽  
Consumer Satisfaction ◽  
Shear Force ◽  
Muscle Fibres ◽  
Type I ◽  
Post Mortem ◽  
Beef Heifers ◽  
Holstein Friesian ◽  
Main Effects ◽  
Sire Breed

The effects on tenderness of extended ageing of longissimus thoracis (LT, striploin) muscle that differed in structure and composition were examined. Spring-born Angus × Holstein-Friesian heifers (n = 48) and Belgian Blue × Holstein-Friesian heifers (n = 48) were slaughtered, within sire breed, at 20 or 25 mo of age. Approximately 48 h post-mortem, LT steaks (2.5 cm) were removed, and either stored at −20°C for chemical analysis or vacuum-packed, stored at 2°C for 7, 14 or 28 d post-mortem and then at −20°C pending Warner–Bratzler shear force (WBSF) analysis. Muscle from Angus-sired heifers had higher (P < 0.001) intramuscular fat (IMF) concentration, lower (P < 0.001) proportion of type IIX muscle fibres and higher (P < 0.001) proportion of type IIA and type I muscle fibres compared to muscle from Belgian Blue-sired heifers. Collagen characteristics did not differ between sire breeds. Later slaughter increased (P < 0.001) IMF concentration and decreased (P < 0.001) total and insoluble concentrations and collagen solubility. There were no interactions between the main effects for WBSF and no difference between sire breeds. Later slaughter and increasing the duration of ageing decreased (P < 0.05) WBSF. Based on threshold WBSF values in the literature, all samples would be considered tender (<39 N) after 7 d ageing. Untrained consumers are likely to detect the decrease in WBSF from 7 to 14 d ageing but not due to further ageing. Within the production system examined and based on WBSF data, extending LT ageing to 28 d is not necessary to ensure consumer satisfaction.

Identifying QTL for meat quality and carcass composition traits in Blackface sheep

2005 ◽  
Vol 2005 ◽  
pp. 45-45
Author(s):  
E. Karamichou ◽  
G.R. Nute ◽  
R.I. Richardson ◽  
K. McLean ◽  
S.C. Bishop
Keyword(s):  
Meat Quality ◽  
Quantitative Traits ◽  
Carcass Composition ◽  
Farm Animals ◽  
Meat Production ◽  
Livestock Species ◽  
Sheep Meat ◽  
Qtl Identification ◽  
Genomic Regions ◽  
Qtl Effects

The development of genetic markers and their application to farm animals has progressed rapidly, opening new prospects for identifying chromosomal regions that control quantitative traits (quantitative trait loci or QTL). However, there is less activity in QTL identification in sheep than in other livestock species. Surprisingly few QTL have been published for traits of direct relevance to sheep meat production, apart from studies of individual major genes such as the callipyge locus (Freking et al, 2002). This suggests there may be more QTL effects still to be found in sheep. Hence, this study aims to identify QTL for carcass composition and meat quality traits. This will provide a basis for targeting genomic regions to verify QTL in independent sheep populations.

scholarly journals Physicochemical properties of meat from Bos taurus and Bos indicus

2011 ◽  
Vol 40 (6) ◽  
pp. 1250-1259 ◽  
Author(s):  
Maria Cristina Bressan ◽  
Erika Cristina Rodrigues ◽  
Lizandra Vercezi Rossato ◽  
Eduardo Mendes Ramos ◽  
Luis Telo da Gama
Keyword(s):  
Physicochemical Properties ◽  
Meat Quality ◽  
Shear Force ◽  
Positive Relationship ◽  
Bos Taurus ◽  
Bos Indicus ◽  
Post Mortem ◽  
Fresh Meat ◽  
Lower Shear ◽  
Before And After

The objective of this study was to characterize meat quality in Bos taurus and Bos indicus and to determine the influence of finishing system and genetic group on the physicochemical properties of the longissimus thoracis at 24 hours and 10 days post mortem (1ºC). The sample included 160 bulls of the B. taurus (n=75) and B. indicus (n=85) groups, finished either on pasture (n=46) or with grain supplementation (n=114), slaughtered at a carcass weight of 270 to 300 kg. Pasture-finished animals had higher pH, lower red content and a fat content 2.5 times lower than those finished with supplementation. Meat from supplement-finished animals had lower shear force in comparison to that from animals finished on pasture, with means of 7.7 and 8.5 kg at 24 hours, and of 5.5 and 5.9 kg at 10 days, respectively. Samples of B. taurus and B. indicus were similar in moisture and protein, but B. taurus presented higher means for ash and lower means for fat. Aged samples of B. indicus finished on pasture showed lower values for lightness and yellowness. Overall, lightness and yellow content increased and red content decreased with 10-day ageing. Means for shear force were lower in B. taurus than in B. indicus, with differences of 1.4 kg in fresh meat and 0.6 kg in aged samples. The reduction in shear force with ageing was more pronounced in samples with higher initial shear force, in spite of the positive relationship between shear force before and after ageing.

Effects of a non-synonymous CBG gene single nucleotide polymorphism (SNP) on meat-quality traits in Berkshire pigs

2016 ◽  
Vol 96 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Seul Gi Kwon ◽  
Jung Hye Hwang ◽  
Da Hye Park ◽  
Tae Wan Kim ◽  
Deok Gyeong Kang ◽  
...  
Keyword(s):  
Moisture Content ◽  
Meat Quality ◽  
Shear Force ◽  
Cooking Loss ◽  
Quality Traits ◽  
Post Mortem ◽  
Single Nucleotide ◽  
Meat Quality Traits ◽  
Berkshire Pigs ◽  
Water Holding

Corticosteroid-binding globulin (CBG) is a plasma transport protein that has glucocorticoid-binding activity. In the present study, we identified CBG gene expression in several tissues of four pig breeds: Berkshire, Duroc, Landrace, and Yorkshire. Expression of CBG mRNA was detected in the liver of all four breeds, and was the highest in Berkshire pigs. We also found single nucleotide polymorphisms (SNPs) in the CBG gene from Berkshire pigs, including SNP c.919G>A, which corresponds to 307G>R. We analyzed the relationships between this CBG variant and various meat-quality traits. The SNP was significantly associated with backfat thickness, post-mortem pH24h, meat color [CIE a* (redness), CIE b* (yellowness)], water-holding capacity, fat content, moisture content, protein content, cooking loss, and shear force. However, the effects differed by gender: the values were significantly associated with almost all traits in gilts, whereas only cooking loss and shear force were shown significantly in barrows. The variant G allele was associated with decreases in backfat thickness, post-mortem pH24h, CIE a*, fat content, and cooking loss, but with increases in CIE b*, water-holding capacity, moisture content, protein content, and shear force. Because the general correlation between meat-quality traits were not validated in the present study, we suggest that certain SNP might be used in the restrictive application to distinguish meat-quality traits.

Unravelling the complex interactions between genetics, animal age and nutrition as they impact on tissue deposition, muscle characteristics and quality of Australian sheep meat

2007 ◽  
Vol 47 (10) ◽  
pp. 1229 ◽  
Author(s):  
R. D. Warner ◽  
D. W. Pethick ◽  
P. L. Greenwood ◽  
E. N. Ponnampalam ◽  
R. G. Banks ◽  
...  
Keyword(s):  
Meat Quality ◽  
Subcutaneous Fat ◽  
Intramuscular Fat ◽  
Carcass Composition ◽  
Early Weaning ◽  
Fat Percentage ◽  
Complex Interactions ◽  
Sheep Meat ◽  
Australian Sheep

The combined effects of age and genetics and Poll Dorset sire and growth path were studied in two separate experiments (n = 595 and 627, respectively). In the first experiment, containing genotype crosses typically used in Australia (Merino, Poll Dorset, Border Leicester) and sires selected for growth or muscling, sheep were slaughtered at 4, 8, 14 and 22 months. The second experiment used Poll Dorset sires selected for high muscling, fat or growth with progeny having two levels of nutrition postweaning. Border Leicesters expressed higher levels of carcass fat percentage and intramuscular fat and produced the heaviest carcass. Merinos had the lowest subcutaneous fat depth and highest carcass lean percentage when compared at the same age. The progeny of Poll Dorset sires selected for high muscling (PDm) expressed a shift toward glycolytic fibres relative to those from Merino sires, and PDm sires produced progeny with reduced spine and limb length and higher carcass muscle : mineral ratios, suggesting skeletal stunting. Genotype meat quality differences were minimal except that PDm sire topsides were tougher and Merinos produced higher pH meat. With age (4–22 months), lambs became heavier and fatter, fibres shifted towards oxidative and away from glycolytic, muscle myoglobin increased, the meat became darker and redder and tenderness declined. Early weaning had no effect on the time to reach slaughter weight, provided nutrition was not restricted. The sire genetics influence on the carcass composition far outweighed the effect of nutrition postweaning. Lambs on a restricted diet tended to have less acceptable meat quality but this was not evident in lambs from sires selected for high fatness. Sensory tenderness was improved and intramuscular fat was higher in lamb progeny from sires selected for high fatness.

Sire and growth path effects on sheep meat production. 2. Meat and eating quality

2007 ◽  
Vol 47 (10) ◽  
pp. 1219 ◽  
Author(s):  
D. L. Hopkins ◽  
D. F. Stanley ◽  
E. S. Toohey ◽  
G. E. Gardner ◽  
D. W. Pethick ◽  
...  
Keyword(s):  
Shear Force ◽  
Sarcomere Length ◽  
Subcutaneous Fat ◽  
Eating Quality ◽  
Meat Production ◽  
Growth Path ◽  
Treatment Groups ◽  
Sheep Meat ◽  
Australian Sheep ◽  
The Impact

The meat and eating quality characteristics of 627 crossbred lamb progeny from 20 Poll Dorset sires were studied. The sires were selected on the basis of Australian sheep breeding values (ASBVs) for postweaning growth (PWWT), depth of loin muscle (PEMD) and subcutaneous fat (PFAT). Lambs were either weaned at 20- or 30-kg liveweight and then within each of these groups held at their weaning weight for 55 days or fully fed, giving four treatment groups. Restricted lambs were realimentated subsequent to the period of feed restriction and the lambs within each treatment group were slaughtered when their mean liveweight reached 45 kg.Shear force of the M. longissimus thoracis et lumborum (LL) decreased with temperature at pH 6.0, increased with LL ultimate pH and decreased as sarcomere length increased. Within LL aged for 5 days there was no difference between (P > 0.05) between treatments for shear force. There was a treatment effect on M. semimembranosus (SM) shear force, such that for a sire having an average ASBV PWWT of 9.34, topsides from lambs early weaned and restricted had significantly (P < 0.05) lower values. Further within these same lambs, i.e. early weaned and restricted, as the sire ASBV PWWT increased there was a significant (P < 0.001) reduction in shear force. There was a significant (P < 0.05) increase in sensory tenderness as the sire ASBV PFAT increased and across the range of ASBV PFAT this represented a change in sensory tenderness of four points. Overall liking increased with an increase in the temperature at pH 6.0 (P < 0.05) with a coefficient of 0.43 ± 0.19. There was a significant (P < 0.05) interaction between feeding level and the sire ASBV PFAT, such that for restricted fed lambs overall liking increased as the ASBV PFAT increased (coefficient 2.80 ± 0.89) after adjusting for temperature at pH 6.0, but this is not the case for fully feed lambs (coefficient –0.01 ± 0.89). Subtle interactions between sire ASBVs and growth path suggest that the impact of a period of restriction and refeeding on meat and eating quality will be meditated by the sire genetics.

scholarly journals 3. The Impact of Ante- and Post-Mortem Factors on the Incidence of Pork Defective Meat – A Review

2016 ◽  
Vol 16 (2) ◽  
pp. 333-345 ◽  
Author(s):  
Barbara Sionek ◽  
Wiesław Przybylski
Keyword(s):  
Meat Quality ◽  
International Standards ◽  
Stress Factors ◽  
Meat Production ◽  
Post Mortem ◽  
Electrical Method ◽  
Production Chain ◽  
The Impact ◽  
Quality Features

Abstract The occurrence of defective meat depends on factors affecting meat quality at the various stages of meat production. Defective meat has a broad definition and includes any property of meat that will dissatisfy end-users. For consumers the main meat quality features are colour, taste and texture (tenderness and juiciness). For processors and butchers very important are technological quality features: water holding capacity, pH, content of connective tissue, fat and protein. The functionality of defective meat is limited. The risk of incidence of defective meat is a result of the combination of ante-mortem and post-mortem factors. The ante-mortem factors are linked with the procedure at the lairage, the slaughtering factors, such as the method of stunning, and the post-mortem factors, including processing of meat carcasses. The ante-mortem factors such as genotype, gender, breeding conditions, nutrition, transport conditions, stress, weather conditions and the methods of slaughter are considered of primary importance for the quality of pork. It is estimated that 40% of meat defects are due to the procedure at the lairage. The impact of stressors causes a loss of weight of the pigs, contributes, in extreme cases, to the death of porkers, increases the risk of incidence of defective meat. Mixing animals from different herds is the cause of stress which leads to aggression and fights between animals. Limiting the stress factors is essential for improving the quality of pork. The applied stunning method affects the quality of meat. Physical stress during electrical stunning is associated with risk of an accelerated post-mortem glycolysis, contributing to the rapid decrease in pH. In comparison with the electrical method, stunning with carbon dioxide causes less stress in swine. In order to reduce the occurrence of defective meat, bleeding should be carried out as soon as possible directly after stunning. Deterioration of the quality of meat in the production chain can occur at any stage and is most often associated with the lack of compliance with the standards. The studies on the improvement of livestock breeding, transport and marketing carried out over a number of years contributed to the introduction of international standards and, consequently, to the reduction of quality and quantity losses in pork.

Eating quality of conventionally chilled sheep meat

2006 ◽  
Vol 46 (7) ◽  
pp. 897 ◽  
Author(s):  
D. L. Hopkins ◽  
E. S. Toohey
Keyword(s):  
Significant Interaction ◽  
Shear Force ◽  
Full Range ◽  
Eating Quality ◽  
Rating Score ◽  
Ph Values ◽  
Sheep Meat ◽  
Ranking Score ◽  
The Mean

The meat and eating quality of the M. longissimus et lumborum (LL) from 80 adult sheep carcasses was examined. Half of the carcasses were subjected to the full range of electrical inputs that are routinely used at the abattoir: immobilisation, spinal discharge and high voltage stimulation (HVS), whereas the other half of the carcasses were subjected to all electrical inputs except HVS. HVS significantly decreased the first pH values and increased the average predicted temperature at pH 6.0. When the shear force of samples aged for 1 day was examined (n = 77), there was a significant effect of stimulation, such that non-stimulated meat was tougher. For a reduced sample (n = 40), the most influential effect on shear force was aging, with no significant effect of stimulation or interaction between stimulation and aging. This was such that aging reduced the percentage of samples with a shear force above 50 N from 75% after 1 day to 17.5% after 7 days of aging for the 40 LLs. When the LLs were aged for 7 days, there was no effect of stimulation on eating quality traits including tenderness, flavour, juiciness or overall liking. Based on the data for the LLs aged for 7 days, a relationship between overall liking and the overall ranking score was derived. Predicted overall liking scores at each rating score were derived, from which it was determined that to achieve a rating score of 3 (good every day), the overall liking score had to be 57. There was a significant interaction between category (less or greater than 57) and stimulation, such that for the less than 57 category, the mean overall liking score was lower for samples from non-stimulated carcasses (46.1) than those from stimulated carcasses (54.4). In the greater than 57 category, there was no difference between stimulated and non-stimulated samples with mean overall liking scores of 67.2 and 70.8, respectively. In total, 14% of samples had overall liking scores below 57. These results show that the proportion of very poor samples is reduced with stimulation even with aging and this is a very important outcome.

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