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.

Determinants of consumer willingness to pay for quality-graded Australian sheep meat

2018 ◽  
Vol 58 (9) ◽  
pp. 1692 ◽  
Author(s):  
Kara Tighe ◽  
Oscar Cacho ◽  
Stuart Mounter ◽  
Renato Villano ◽  
Alex Ball ◽  
...  
Keyword(s):  
Willingness To Pay ◽  
Eating Quality ◽  
Quality Differentiation ◽  
Sheep Meat ◽  
Quality Grading ◽  
Australian Sheep ◽  
Quality Specifications ◽  
Consumer Age ◽  
Meat Samples ◽  
The Impact

The present study investigated the influence of a quality-grading system, demographic information and consumption preferences on consumer willingness to pay (WTP) for sheep meat. Eating quality was defined by four grades developed by the Meat Standards Australia (MSA) sheep meat-grading scheme. These grades were based on consumer palatability scores for cooked sheep-meat samples and described as 2-star (‘unsatisfactory’ quality), 3-star (‘good every day’ quality), 4-star (‘better than every day’ quality) and 5-star (‘premium’ quality). Currently, sheep-meat available in Australian retail outlets that meets MSA quality specifications is trademarked as ‘MSA graded’ and consists of lamb that falls into at least the 3-star quality band. There is no distinction made between 3-, 4- and 5-star-graded product. A challenge for marketers would be pricing the product by these three grades should finer-quality differentiation be adopted. The present study evaluated consumer WTP for the MSA quality grades and interactions with consumer demographic factors and consumption preferences. Results clearly showed that consumers were willing to pay less for the 2-star grade and more for 4- and 5-star grades, than for 3-star grade. Robust results for the impact of demographic and consumption preferences on WTP were limited to consumer age, occupation, income level and the interaction between MSA grade and consumer age.

Sire and growth-path effects on sheep meat production. 3. Fascicular structure of lamb loin muscle (m. longissimus lumborum) and the impact on eating quality

2009 ◽  
Vol 49 (3) ◽  
pp. 239 ◽  
Author(s):  
P. G. Allingham ◽  
W. Barris ◽  
A. Reverter ◽  
V. Hilsenstein ◽  
R. van de Ven ◽  
...  
Keyword(s):  
Connective Tissue ◽  
Rapid Growth ◽  
Seam Thickness ◽  
Eating Quality ◽  
Meat Production ◽  
Growth Path ◽  
Eye Muscle ◽  
Positive Effects ◽  
Longissimus Lumborum ◽  
The Impact

The effects of sire genetics and growth path on the fascicular structure (FS) of lamb loin muscle (m. longissimus lumborum; LL) and the consequences for eating quality were studied in progeny (n = 299) of 20 Poll Dorset sires and Merino ewes. Sires were selected on the basis of their Australian sheep breeding values (ASBV) for post-weaning growth (PWWT), loin eye muscle depth (PEMD) and subcutaneous fat (PFAT). Growth of lambs was varied by time of weaning (early or late) and by feeding level within weaning group, where lambs were either fully fed throughout or were feed restricted for 55 days then re-alimented to achieve liveweight of ~45 kg at slaughter. The FS variables were determined in differentially stained histological sections of LL by using automated image segmentation and circle geometry methodology and were defined as percentage connective tissue, perimysial seam thickness and fascicular width. Sire ASBV was not a significant covariate to measures of FS, despite ASBV-related effects on growth, carcass leanness and fatness. Independent of weaning time, faster growth was induced by re-alimentation of feed-restricted lambs, resulting in LL with less connective tissue as a percentage of cross-sectional area and larger fascicles than for fully fed peers. The direction of the perimysial seam thickness response varied with treatment and time of weaning. Rapid growth of re-alimented early weaned restricted lambs resulted in thinner seams than for fully fed peers, whereas the opposite response was observed in the late-weaned lamb contrast. This suggests that the weight and age of the lamb at the time of nutritional compromise and re-alimentation are important factors in determining the thickness of perimysial connective-tissue seams. Whilst the evidence confirms differential accretion of the myofibrillar and connective tissues and despite reports of positive effects on tenderness brought about by such changes, variation in structural measures was not associated with variation in either objective measures (compression) or sensory scores for tenderness of the loin muscle. The data from the present study support the tenet that rapid growth before slaughter, combined with appropriate sire genetics, will not compromise the physical characteristics and sensory qualities of the meat.

The Australian sheep industry - undergoing transformation

2010 ◽  
Vol 50 (12) ◽  
pp. 991 ◽  
Author(s):  
J. B. Rowe
Keyword(s):  
New Technologies ◽  
Economic Value ◽  
Genetic Selection ◽  
High Rate ◽  
Meat Production ◽  
Sheep Industry ◽  
Sheep Meat ◽  
Productivity Gain ◽  
Australian Sheep ◽  
Meat Market

Changes in the sheep industry over the last 20 years represent a trend that is unlikely to be reversed. The farm gate value of wool production has decreased from over $6 billion to ~$2.5 billion and the value of sheep meat has increased from $0.5 to $2.2 billion. Wool and meat are now on an equal footing in terms of the economic value of each sector of the industry. Future profitability of both wool and sheep meat production depends on achieving a high rate of productivity gain and improving quality attributes valued by consumers. Wool and sheep meat cannot compete on price or volume with synthetics and cotton in the textile market or with chicken and pork in the meat market. Differentiation based on quality and consistency needs to be measurable and clearly understood by consumers. The combination of genetic selection and good management can deliver improved productivity gain. Skills development and training will be essential for the industry to fully utilise available knowledge and new technologies.

The influence of pre-weaning nutrition on biochemical and myofibre characteristics of bovine semitendinosus muscle

2001 ◽  
Vol 52 (9) ◽  
pp. 891 ◽  
Author(s):  
Peter G. Allingham ◽  
Gregory S. Harper ◽  
David W. Hennessy ◽  
V. Hutton Oddy
Keyword(s):  
Muscle Development ◽  
Late Pregnancy ◽  
High Energy ◽  
Eating Quality ◽  
Growth Path ◽  
Semitendinosus Muscle ◽  
Calf Growth ◽  
Treatment Groups ◽  
Sarcoplasmic Protein ◽  
Biophysical Attributes

This study investigates pre-weaning growth of cattle and its effect on biochemical and histochemical markers of muscle development and subsequent biophysical attributes of eating quality. Combinations of cow (late pregnancy to mid-lactation) and pre-weaning (varying duration of access to a high-energy ration) supplementation were used to vary calf growth to weaning in 6 treatment groups. After weaning, calves were grazed together on pasture (backgrounding) and then grown rapidly on a feedlot ration (finishing) until slaughter. Biochemical and myofibre characteristics were determined in semitendinosus muscle samples collected just prior to weaning (7 months), at the end of backgrounding (13 months), and at slaughter (17 months). The concentration of sarcoplasmic protein and the activity of lactate dehydrogenase in the muscle at weaning were associated with differences in pre-weaning growth and both variables correlated positively with liveweight at weaning. Isocitrate dehydrogenase activity varied with sex, not treatment, at weaning and at the end of backgrounding. The size of myofibres at weaning related to differences in growth path and correlated positively with liveweight. Pre-weaning growth effects on these characteristics were not evident at slaughter. Biophysical properties of the meat were not affected by earlier growth path treatment, and were not correlated with biochemical characteristics or myofibre type profile. Variation in both shear peak force and adhesion was related to sex. We conclude that the effects of divergent early life growth do not persist 10 months after weaning, at least in meat quality characteristics.

The impact of processing on sensory and objective measurements of sheep meat eating quality

2005 ◽  
Vol 45 (5) ◽  
pp. 561 ◽  
Author(s):  
J. M. Thompson ◽  
D. L. Hopkins ◽  
D. N. D'Souza ◽  
P. J. Walker ◽  
S. R. Baud ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Biceps Femoris ◽  
Eating Quality ◽  
Sensory Testing ◽  
Meat Eating ◽  
Sheep Meat ◽  
Per Se ◽  
The Impact ◽  
Processing Factors ◽  
Age Category

The impact of processing factors on sheep meat eating quality was investigated in an experiment in which stimulation (stimulation and no stimulation), chilling rate (fast and slow chilling) and carcass suspension (tenderstretch and normally hung by Achilles tendon) treatments were overlaid on 80 lamb and 40 mutton carcasses processed over 2 days, at 2 different abattoirs. Within each carcass, 3 muscles (M. longissimus thoracics et lumborum, biceps femoris and serratus ventralis) were collected from both sides and aged for 2 of 3 ageing periods (2, 5 or 14 days), before sensory testing for tenderness, juiciness, like flavour and overall liking, using a consumer taste panel. Processing treatments of stimulation and chilling were variable in their effect on the rates of pH and temperature decline and temperature at pH 6 (temp@pH6), between the 4 slaughter groups. Therefore chilling rate and electrical stimulation were considered as tools by which temp@pH6 could be manipulated, rather than as treatment effects per se. Age category (lamb or mutton) had the largest impact on tenderness score, followed by muscle, ageing and carcass suspension. There were significant interactions for tenderness and overall liking scores between muscle × ageing, age category × muscle and carcass suspension × muscle (P<0.05). The magnitude of the tenderstretch advantage in sensory scores was a function of temp@pH6. In normally hung carcasses, the highest sensory scores were evident at about 21°C temp@pH6, with a decrease in sensory scores at high (>30°C) or low (<10°C) temp@pH6. There was a tendency for sensory scores (particularly for the like flavour score) to decline for the biceps femoris when it was stored for extended periods (14 days).

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.

The influence of feeding regimen and lactation length on growth, carcass characteristics and meat quality of once-bred gilts

1996 ◽  
Vol 62 (3) ◽  
pp. 561-571 ◽  
Author(s):  
M. Ellis ◽  
V. R. Fowler ◽  
M. F. Franklin ◽  
J. D. Wood ◽  
M. A. Varley
Keyword(s):  
Meat Quality ◽  
Growth Rates ◽  
Subcutaneous Fat ◽  
Live Weight ◽  
Eating Quality ◽  
Treatment Groups ◽  
Lactation Length ◽  
Lean Growth ◽  
Pregnancy And Lactation ◽  
Ad Libitum

AbstractA study was made to investigate the influence of pregnancy feeding level (ad libitum (AL) and restricted (R); 2·0 kg food per day) and lactation length on growth, carcass, meat quality and processing characteristics of pregnant gilts (P) slaughtered after weaning on day 0 (P·0), day 10 (P·10) or day 35 (P·35) after farrowing. Non-pregnant (NP) control gilts were slaughtered at live weights of approximately 95 kg (NP-L), 135 kg (NP-M), and 160 kg (NP-H). P gilts were mated at an average age of 172 days and an average live weight of 97 kg. Pregnancy per se reduced live weight and lean growth rates compared with NP-H animals which were slaughtered at a similar age to the once-bred animals. Weight loss during lactation tended to increase with lactation length and was higher for gilts given food ad libitum during pregnancy compared with restricted animals. The weight of closely trimmed lean in the carcass was similar for the P·0, P·10 and P·35 groups (59·5 v. 62·2 v. 58·8 kg respectively; average s.e. 2·42) and all once-bred gilt groups virtually doubled trimmed lean yields during pregnancy and lactation. Curing yields were similar for P and NP gilts. As lactation length increased, the fat content of the longissimus dorsi and of the overlying subcutaneous fat layers tended to decrease and the moisture content of these two tissues increased. The major impact offeeding level was on fat levels which were significantly higher for AL animals. Trimmed lean yields were also higher for AL gilts suggesting that lean growth rates were not being maximized on the R feeding regime. Subjective muscle colour scores indicated that the longissmus dorsi from P gilts was darker than from NP-L animals and muscle colour tended to become darker with increasing lactation length. There were few significant differences between treatment groups for eating quality. Meat from once-bred gilts was generally judged to be tougher than that from NP-L animals and toughness generally increased with lactation length. This study confirms the potential of the once-bred gilt as an efficient producer of pig meat but raises issues regarding meat quality that require further research.

Validating the benefits of a medium voltage electrical stimulation unit at an abattoir in Western Australia

2008 ◽  
Vol 48 (7) ◽  
pp. 898 ◽  
Author(s):  
R. H. Jacob ◽  
K. L. Pearce ◽  
N. Smith
Keyword(s):  
Electrical Stimulation ◽  
Western Australia ◽  
Shear Force ◽  
Sarcomere Length ◽  
Quality Parameters ◽  
Eating Quality ◽  
Colour Stability ◽  
Visual Appearance ◽  
Medium Voltage ◽  
Optimal Setting

Two experiments were done following installation of a new generation medium voltage electrical stimulation unit at a commercial lamb abattoir in Western Australia. The first experiment was designed to optimise settings in relation to rate of pH decline post mortem. The second experiment was designed to investigate the eating quality and visual appearance effects of the optimal setting. In the first experiment, nine different settings were compared with a control using 60 lamb carcasses from each of 10 different consignments. The rate of pH × temperature decline was optimal with a pulse width of 2.5 ms and a current of 1.2 A. In the second experiment, 80 lamb carcasses consisting of four carcasses from each of 20 consignments were examined for various eating quality parameters including sarcomere length, shear force, bloom colour and colour stability. Two of the lambs from each consignment were stimulated and two were not stimulated. Stimulation improved compliance with the Sheep Meat Eating Quality (SMEQ) pH × temperature ‘window’ for domestic and frozen product but not for long ship product. Colour was improved by electrical stimulation without changing colour stability. There was a small effect on sarcomere length and no effect of stimulation on shear force measured at day 1 and day 10 after slaughter.

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.

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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