The Experts below are selected from a list of 17217 Experts worldwide ranked by ideXlab platform
D L Hopkins - One of the best experts on this subject based on the ideXlab platform.
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adapting seasonal Sheep production to year round fresh Meat and halal market in norway
Sustainability, 2019Co-Authors: Muhammad Azher Bhatti, D L Hopkins, Thomas Williams, Leif Jarle Asheim, Geir Steinheim, Michael Campbell, Lars Olav Eik, Peter Wynn, Tormod AdnoyAbstract:Norway is the largest Sheep Meat producer among Nordic countries with more than 1.3 million lambs and Sheep slaughtered in 2017. The Sheep industry is limited by the need for in-house feeding during the winter months. In summer, Norwegian Sheep are mainly kept on rangeland pastures, with sufficient feed for almost double the current Sheep population. Lambs are slaughtered over a three- to four-month period from September to December with a peak in September–October, providing a surplus of lamb, much of which is subsequently frozen, followed by eight months during which fresh produce is in limited supply. Norwegian consumers eat an average of 5.4 kg of Sheep Meat per person per year, much of which is purchased as a frozen product. The Muslim (4.2% of the population) preference for year-round halal Meat, with an increased demand on the eve of the Muslim Meat festival (Eid al-Adha), has the potential to boost demand, particularly in Oslo. This paper provides an overview of the Norwegian Sheep farming system, the current market value chains, and the potential to meet the demand for halal Meat in Norway (specifically during the Muslim Meat festival—Eid al-Adha) to the advantage of both consumers and Sheep farmers.
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retail colour stability of lamb Meat is influenced by breed type muscle packaging and iron concentration
Meat Science, 2017Co-Authors: D L Hopkins, R H Jacob, R D Warner, G KearneyAbstract:The longissmus lumborum (LL) and semimembranosus (SM) muscles from 391 lamb carcasses, derived from various breed types, were used to investigate the effect of animal/muscle factors, packaging type [over-wrap (OW) or high oxygen modified atmosphere packaging (MAPO2)] and duration of display on redness of Meat during simulated retail display. Using statistical models the time required (in days) for redness to reach a threshold value of 3.5 (below this is unacceptable) was predicted. High levels of iron in the SM, but not LL, reduced the time for redness to reach 3.5 by 2-2.6days in MAPO2 and 0.5-0.8days in OW. The greater the proportion of Merino breed type, the shorter was the time for redness to reach the value of 3.5, an effect consistent across muscles and packaging types. In summary, breed type, packaging format, muscle and muscle iron levels had a significant impact on colour stability of Sheep Meat in oxygen-available packaging systems.
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consumption patterns and consumer attitudes to beef and Sheep Meat in china
American Journal of Food and Nutrition, 2016Co-Authors: Yanwei Mao, D L Hopkins, Yimin Zhang, Xin LuoAbstract:This review paper provides an overview of the Meat production status in China and Chinese consumer requirements with respect to red Meat, especially for beef and Sheep Meat. The analysis of Meat output, consumption and price indicates that the production and consumption of beef and Sheep Meat has increased in China, and the price of Meat has risen significantly as the consumption requirements have risen. The quantity and quality requirements of Chinese consumers in terms of beef and Sheep Meat are different between urban and rural residents and regions, and are influenced by price, income, religious beliefs, flavor, nutritional value, dietary habits, safety and eating quality. The demand for high quality and the concern with respect to the safety of beef and Sheep Meat by Chinese consumers is increasing, but there are gaps between the requirements and the supply, despite the increased the importation of beef and Sheep Meat. Lastly, the paper outlines what the Meat industry and researchers should do to promote the strength of Chinese Meat industry, and gives guidance to exporting countries with respect to the quality Chinese consumers are likely to expect in the future.
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effect of genotype gender and age on Sheep Meat quality and a case study illustrating integration of knowledge
Meat Science, 2014Co-Authors: D L Hopkins, S I MortimerAbstract:Subtle breed differences exist for Meat quality traits and the Merino does stand out, although many comparisons are confounded by production site or lack of processing intervention. Despite this, the Merino does seem to have a propensity to produce Meat with a higher pH and reduced colour stability under extended ageing. Use of the Merino in a crossbreeding system not only provides benefits from hybrid vigour, but also overcomes the Meat quality constraints of pure Merinos. Genetic evaluation for lamb production has enabled impressive genetic gains, but an overemphasis on lean Meat production has had to be addressed to counter adverse effects on Meat quality traits like eating quality. In this regard, the development of genomic selection has provided a methodology for accurate prediction of genetic merit and applying balanced breeding objectives. The potential for negative Meat quality effects has stemmed adoption of non-castration approaches, but ensuring that lamb is young when slaughtered does provide brand integrity.
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preliminary investigation on the relationship of raman spectra of Sheep Meat with shear force and cooking loss
Meat Science, 2013Co-Authors: Heinar Schmidt, Rico Scheier, D L HopkinsAbstract:Abstract A prototype handheld Raman system was used as a rapid non-invasive optical device to measure raw Sheep Meat to estimate cooked Meat tenderness and cooking loss. Raman measurements were conducted on m. longissimus thoracis et lumborum samples from two Sheep flocks from two different origins which had been aged for five days at 3–4 °C before deep freezing and further analysis. The Raman data of 140 samples were correlated with shear force and cooking loss data using PLS regression. Both sample origins could be discriminated and separate correlation models yielded better correlations than the joint correlation model. For shear force, R2 = 0.79 and R2 = 0.86 were obtained for the two sites. Results for cooking loss were comparable: separate models yielded R2 = 0.79 and R2 = 0.83 for the two sites. The results show the potential usefulness of Raman spectra which can be recorded during Meat processing for the prediction of quality traits such as tenderness and cooking loss.
D W Pethick - One of the best experts on this subject based on the ideXlab platform.
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genotype and age effects on Sheep Meat production 4 carcass composition predicted by dual energy x ray absorptiometry
Australian Journal of Experimental Agriculture, 2007Co-Authors: En Ponnampalam, D L Hopkins, D W Pethick, F R Dunshea, K L Butler, R D WarnerAbstract:This study compares the carcass composition of different genotypes of Australian Sheep slaughtered at four ages (110, 236, 412 and 662 days of age, or 4, 8, 14 and 22 months of age). The genotypes used 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). Approximately 150 mixed sex animals were slaughtered at each age and the right sides (half carcass) were scanned by dual energy X-ray absorptiometry (DXA) for chemical lean, fat and bone mineral percentages of the carcass. Carcass lean percentage decreased (P 0.1) between PDg × M and PDm × M in either chemical lean or fat percentages at any age but ash mineral percentage was higher in the PDg × M genotype at older ages (P < 0.05). This in turn led to differences in chemical lean : ash mineral content at later ages between PDg × M and PDm × M. Wethers had higher chemical lean (P < 0.05) and lower fat (P < 0.05) percentages in the carcass than ewes at all ages but ash mineral and chemical lean : ash mineral content did not differ between sexes. It was clear that the level of chemical lean or fat or ash mineral composition reached by some genotypes at one age was equivalent to that reached by other genotypes at the next measurement age. Those genotypes that reach a specification at younger ages will be more productive for Meat production. Purebred Merino genetics will always be less productive in terms of carcass weight and muscle related productive traits (loin weight, semitendinosus muscle weight, eye muscle area) than BL and PD genetics, but the relative productivity of PD and BL genetics will depend on the traits used in the specification [see also Ponnampalam EN, Hopkins DL, Butler KL, Dunshea FR, Warner RD (2007) Genotype and age effects on Sheep Meat production. 2. Carcass quality traits. Australian Journal of Experimental Agriculure 47, 1147–1154]. The results suggest that selection for muscling had a greater impact on reducing ash mineral content associated with bone mineral mass than on increasing lean mass in the carcass.
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a model relating a function of tenderness juiciness flavour and overall liking to the eating quality of Sheep Meat
Animal Production Science, 2005Co-Authors: A B Pleasants, J M Thompson, D W PethickAbstract:A probabilistic model of consumer perception of Sheep Meat eating quality is constructed on the basis of a sensory score derived from consumer evaluation of tenderness, juiciness, flavour and overall liking. The model includes consideration of the variability of the sensory score within a mob, the probability that Meat with a given sensory score will be perceived by the consumer as correctly classified, and the distribution of the average sensory score within an eating quality grade. Based on this information the model can calculate the frequency with which Sheep Meat given a sensory score that will fail to meet the consumer expectation of the allocated eating quality grade. The model provides a basis for integrating the information gathered on Sheep Meat eating quality to formulate a method of classification and to quantify the reliability of this classification. This information can be applied in a variety of ways to evaluate the efficacy, financial or otherwise, of a retailer adopting a given Sheep Meat eating quality classification based on the nominated eating quality score.
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lamb and Sheep Meat eating quality industry and scientific issues and the need for integrated research
Australian Journal of Experimental Agriculture, 2005Co-Authors: B C Russell, G Mcalister, I S Ross, D W PethickAbstract:This paper provides an introduction to the special edition of the Australian Journal of Experimental Agriculture dedicated to an integrated research program aimed at understanding the critical control points which determine the consumer defined eating quality of Australian lamb and Sheep Meat. The reasons for a general approach in the research is outlined.
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the impact of processing on sensory and objective measurements of Sheep Meat eating quality
Australian Journal of Experimental Agriculture, 2005Co-Authors: J M Thompson, D L Hopkins, D N Dsouza, P J Walker, S R Baud, D W PethickAbstract: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 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).
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the effect of dietary treatment on Meat quality and on consumer perception of Sheep Meat eating quality
Animal Production Science, 2005Co-Authors: D W Pethick, D L Hopkins, D N Dsouza, J M Thompson, R H Davidson, R H Jacob, P J WalkerAbstract:The aim of this experiment was to test the effects of dietary treatment on Sheep Meat eating quality as perceived by untrained Australian consumers. Six-month-old Suffolk x Merino lambs (n = 192) were allocated to 1 of 4 nutritional treatments for 60-77 days and were fed: (i) an irrigated perennial ryegrass-clover-kikuyu sward; (ii) irrigated perennial ryegrass-clover-kikuyu pasture for 48-61 days then poor quality straw for the last 12-16 days; (iii) a mixed ration treatment consisting of a high-energy pelleted diet (40% barley grain, 30% wheat grain, 15% hay and 12% lupin grain); or (iv) irrigated pasture for 37-51 days followed by a moderate-energy pelleted diet (36% wheat grain, 35% hay and 24.5% lupin grain) for 23-26 days. The starting liveweight of lambs was 31.5-35.5 kg and the final hot carcass weight was 19-20 kg. The nutritional treatment finishing system employing straw feeding for the last 12-16 days was associated with a loss of liveweight during this period, a decreased tissue depth at the GR site and a decreased content of intramuscular fat and glycogen in muscle. Untrained Australian consumers were asked to rate samples (scale 0-100) of the M. longissimus thoracis et lumborum (LL) from lambs for tenderness, liking of flavour, juiciness and overall liking and then classify the Meat as unsatisfactory, good everyday or better than everyday. Straw feeding was also associated with significantly reduced consumer scores for juiciness (P<0.05) and liking of flavour (P<0.10) with no changes in tenderness and overall liking. There was no significant difference in the consumer acceptance of the LL obtained from lambs finished on pasture v. grain-based diets. It is concluded that nutritional finishing systems should be selected to prevent animals from losing weight pre-slaughter and that decisions on pasture v. grain based feeding systems be based on the cost of production.
E.s. Toohey - One of the best experts on this subject based on the ideXlab platform.
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explaining the variation in the shear force of lamb Meat using sarcomere length the rate of rigor onset and ph
Meat Science, 2011Co-Authors: D L Hopkins, E.s. Toohey, T A Lamb, M J Kerr, R Van De Ven, Gordon RefshaugeAbstract:The temperature when the pH=6.0 (temp@pH6) impacts on the tenderness and eating quality of Sheep Meat. Due to the expense, sarcomere length is not routinely measured as a variable to explain variation in shear force, but whether measures such as temp@pH6 are as useful a parameter needs to be established. Measures of rigor onset in 261 carcases, including the temp@pH6, were evaluated in this study for their ability to explain some of the variation in shear force. The results show that for 1 day aged product combinations of the temp@pH6, the pH at 18 °C and the pH at 24 h provided a larger reduction (almost double) in total shear force variation than sarcomere length alone, with pH at 24 h being the single best measure. For 5 day aged product, pH at 18 °C was the single best measure. Inclusion of sarcomere length did represent some improvement, but the marginal increase would not be cost effective.
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some important changes in the australian Sheep Meat processing industry
Animal Production Science, 2008Co-Authors: D L Hopkins, E.s. Toohey, K L Pearce, I RichardsAbstract:In the last 5 years there has been a dramatic increase in the adoption in the Australian Sheep Meat processing industry of electrical technologies designed to streamline processing and improve product quality. Part of this change was initiated by an Australia-wide audit of lamb tenderness in 1997–98 and the development of a program to establish an eating quality scheme for Sheep Meat across Australia. Critically, these initiatives coincided with the development of new ways of administering electrical currents to either bodies or carcasses. Underlying this new approach is the electrocution of carcasses individually on segmented electrodes in a dose responsive way with electricity that has short pulse widths and lower voltages. This paper documents the pivotal factors which have contributed to this level of industry adoption and which has seen 14 abattoirs install the new technology. Of these abattoirs only one previously had any form of stimulation and these abattoirs represent more than 70% of the throughput of Sheep and lambs on a tonnage basis per year in Australia.
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genotype and age effects on Sheep Meat production 3 Meat quality
Australian Journal of Experimental Agriculture, 2007Co-Authors: D L Hopkins, E.s. Toohey, D F Stanley, Lee Martin, Arthur R GilmourAbstract: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.
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effects of lairage time and electrical stimulation on Sheep Meat quality
Animal Production Science, 2006Co-Authors: E.s. Toohey, D L HopkinsAbstract:This paper describes an experiment which examined the effects of lairage time and electrical stimulation on Meat quality and carcass traits in conventionally chilled Sheep Meat. The 120 Merino wethers used in this experiment were sourced on farm and were transported to the abattoir and held in a paddock 1 week before slaughter. The animals were then placed into 2 different pens (replicas). The Sheep were killed at random either at day 1 (n = 60) or day 2 (n = 60). There were 30 animals taken from both pens 1 and 2 each day. Half of these animals were exposed to high voltage stimulation (30 stimulated) and for the other half the high voltage stimulation was turned off (30 control) each day. There was no significant (P>0.05) effect of lairage time on hot carcass weight, GR, initial pH, shear force or cooking loss. However, lairage time had a significant (P 0.05). A significant (P<0.05) interaction between lairage time and stimulation was found for shear force which showed that non-stimulated Meat from Sheep held in lairage for 2 days was tougher than that from stimulated carcasses.
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eating quality of conventionally chilled Sheep Meat
Animal Production Science, 2006Co-Authors: D L Hopkins, E.s. TooheyAbstract: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.
P J Walker - One of the best experts on this subject based on the ideXlab platform.
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effects of animal age on the eating quality of Sheep Meat
Animal Production Science, 2005Co-Authors: D L Hopkins, D N Dsouza, J M Thompson, P J WalkerAbstract:The aim of this work was to test the effects of animal age on consumer perceptions of Sheep Meat quality. Experiment 1 tested eating quality scores (tenderness, liking of flavour, juiciness and overall liking) derived from untrained consumers of grilled M. longissimus lumborum (LL) or M. biceps femoris (BF) derived from Merino ewes ranging from 8.5 to 68.5 months of age. The ewes were derived from one farm and all received a pelleted diet (60% hay, 30% lupin grain and 10% barley grain) that sustained growth between 118 and 173 g/day for at least 22 days pre-slaughter. In experiment 2 consumer testing of grilled LL and roasted BF and M. semimembranosis (SM) was conducted on a commercial line of 12-month-old White Suffolk × Merino lambs (0 erupted incisor teeth) v. a line of Merino yearling Sheep about 22 months old (with either 2 or 4 erupted incisor teeth). The results of experiment 1 showed a significant effect of muscle (LL>BF, P<0.001) and a cubic effect of animal age on the consumer scores for grilled steaks. The cubic relationship was due to Meat from lamb (8.5 months) and hogget (20 months) having higher scores than those of older animals. There was a close relationship between the objective measures of tenderness and the consumer tenderness score (r2 = 0.53, P<0.001). Results of experiment 2 indicated no significant difference between the grilled LL for the crossbred lamb and 22-month-old (2–4 teeth) Merino yearling Sheep. However, the consumer scores for the roasted BF and SM were significantly depressed in the 2–4 tooth yearling Merino categories. In conclusion, this work clearly underpins the current Australian definition of lamb, lamb having better eating-quality attributes than older animals with fully erupted permanent incisor teeth, particularly in muscles from across the carcass. However, this work also highlights the eating quality attributes of older Sheep (6 or more permanent incisor teeth) particularly for the LL, and suggests that negative influences of flavour associated with older Sheep Meat are minimal when the product is served in the absence of subcutaneous and intermuscular fat. Finally, the results suggest the possibility of a new ‘yearling’ Sheep Meat category based on animals in the 2–4-tooth dentition category.
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the impact of processing on sensory and objective measurements of Sheep Meat eating quality
Australian Journal of Experimental Agriculture, 2005Co-Authors: J M Thompson, D L Hopkins, D N Dsouza, P J Walker, S R Baud, D W PethickAbstract: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 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).
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the effect of dietary treatment on Meat quality and on consumer perception of Sheep Meat eating quality
Animal Production Science, 2005Co-Authors: D W Pethick, D L Hopkins, D N Dsouza, J M Thompson, R H Davidson, R H Jacob, P J WalkerAbstract:The aim of this experiment was to test the effects of dietary treatment on Sheep Meat eating quality as perceived by untrained Australian consumers. Six-month-old Suffolk x Merino lambs (n = 192) were allocated to 1 of 4 nutritional treatments for 60-77 days and were fed: (i) an irrigated perennial ryegrass-clover-kikuyu sward; (ii) irrigated perennial ryegrass-clover-kikuyu pasture for 48-61 days then poor quality straw for the last 12-16 days; (iii) a mixed ration treatment consisting of a high-energy pelleted diet (40% barley grain, 30% wheat grain, 15% hay and 12% lupin grain); or (iv) irrigated pasture for 37-51 days followed by a moderate-energy pelleted diet (36% wheat grain, 35% hay and 24.5% lupin grain) for 23-26 days. The starting liveweight of lambs was 31.5-35.5 kg and the final hot carcass weight was 19-20 kg. The nutritional treatment finishing system employing straw feeding for the last 12-16 days was associated with a loss of liveweight during this period, a decreased tissue depth at the GR site and a decreased content of intramuscular fat and glycogen in muscle. Untrained Australian consumers were asked to rate samples (scale 0-100) of the M. longissimus thoracis et lumborum (LL) from lambs for tenderness, liking of flavour, juiciness and overall liking and then classify the Meat as unsatisfactory, good everyday or better than everyday. Straw feeding was also associated with significantly reduced consumer scores for juiciness (P<0.05) and liking of flavour (P<0.10) with no changes in tenderness and overall liking. There was no significant difference in the consumer acceptance of the LL obtained from lambs finished on pasture v. grain-based diets. It is concluded that nutritional finishing systems should be selected to prevent animals from losing weight pre-slaughter and that decisions on pasture v. grain based feeding systems be based on the cost of production.
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effect of Sheep type on Meat and eating quality of Sheep Meat
Australian Journal of Experimental Agriculture, 2005Co-Authors: D L Hopkins, J M Thompson, P J Walker, D W PethickAbstract:The effect of type of lambs and hoggets on eating quality was evaluated using the M. longissimus lumborum (LL) and the M. biceps femoris (BF) from 210 animals. The animals comprised 7 types as follows: Poll Dorset or White Suffolk x (Border Leicester x Merino) (second cross unweaned lambs, mixed sex, 3-5 months of age); Poll Dorset x (Border Leicester x Merino) (second cross weaned lambs, mixed sex, 9-12 months of age); Border Leicester x Merino (BLM; first cross weaned lambs, mixed sex, 9 months of age); Poll Dorset or White Suffolk x Merino (PDM; first cross weaned lambs, wethers, 12 months of age); Merino x Merino (weaned wether lambs, 9-12 months of age); Border Leicester x Merino (BLM; first cross hoggets, mixed sex, 20 months of age); and Poll Dorset or White Suffolk x Merino (PDM; first cross hoggets, wethers, 16 months of age). The animals were sourced from a number of different properties in New South Wales (NSW) (n = 120) and Victoria (n = 90). Each carcass was subjected to high voltage stimulation (700 V) within 1 h of slaughter. All Meat was aged for 5 days before freezing and was subsequently tested by consumers on a 0-100 scale for a number of attributes after cooking using a grilling procedure. The LL from sucker lambs had the lightest colour (highest L* values) with the hoggets having the darkest colour in the NSW group with differences less apparent in the Victorian group. Muscle from first cross and Merino weaned lambs had consistently higher pH levels across the 3 muscles tested (LL; M. semimembranosus; M. semitendinosus) for the NSW group with no differences detected in the Victorian group. LL Meat from second cross sucker and first cross (BLM and PDM) weaned lambs had the highest overall liking score, with that from second cross weaned lambs, BLM hoggets and Merino lambs scored as intermediate, while Meat from the PDM hogget group had the lowest overall liking score. A similar outcome was found for the other sensory attributes with differences between types being lower for juiciness compared with overall liking scores but they were of a similar ranking. For the BF there was some re-ranking of the overall liking scores compared with the LL, with Meat from suckers and first cross PDM lambs and hoggets being intermediate in score while second cross weaned lambs and first cross BLM lambs had the highest scores. The BF from hoggets (BLM) and Merino lambs were given the lowest scores. The lower juiciness score for sucker BF contributed to this change in ranking compared with the LL.
John Sumner - One of the best experts on this subject based on the ideXlab platform.
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relationships between the density of different indicator organisms on Sheep and beef carcasses and in frozen beef and Sheep Meat
Journal of Applied Microbiology, 2007Co-Authors: David R Jordan, David Phillips, Stephen Morris, John Sumner, Ian JensonAbstract:Aim: To describe the relationship between the concentration of different indicator bacteria in red Meat. Methods and Results: Enumeration data for aerobic plate count (APC), Enterobacteriaceae, coliforms and Escherichia coli biotype I were analysed from an Australia-wide survey of beef carcasses, Sheep carcasses, frozen beef and frozen Sheep Meat. In all commodities, there was only low-to-moderate rank correlation (0·16–0·47) between concentration of APC and concentration of each Gram-negative indicator. Rank correlations between counts of Gram-negative indicators were much higher (0·47–0·92) especially when nondetections were excluded from analysis (0·78–0·94). Receiver–operator characteristics analysis showed that detection of coliforms can predict the presence of E. coli biotype I with almost 100% sensitivity but fails to predict absence in 2·7–8·5% of samples not containing E. coli biotype I. Conclusions: Enumeration of coliforms is a useful adjunct to enumeration of E. coli biotype I or Enterobacteriaceae in red Meat. The density of coliforms or Enterobacteriaceae can be used to predict the presence or absence of E. coli biotype I, although when the latter is at low prevalence errors in positive test prediction can be large. Significance and Impact of the Study: A quantitative basis is provided for comparing the concentration of different indicator bacteria measured in the production, regulation and trade of red Meat.
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microbiological quality of australian Sheep Meat in 2004
Meat Science, 2006Co-Authors: David Phillips, Stephen Morris, Ian Jenson, David Jordan, John SumnerAbstract:The third national baseline microbiological survey of Australian Sheep carcases and frozen boneless Sheep Meat was conducted in 2004. Carcases (n = 1117) sampled at 20 slaughter establishments were found to have a mean log total viable count (TVC, 25 °C) of 2.28 cfu/cm2 and Escherichia coli was isolated from 43.0% carcases with a mean log 0.03 cfu/cm2 on positive samples. In samples from 10 boning (fabrication) plants (n = 560) the mean log TVC for frozen boneless Sheep Meat was 1.85 cfu/g and the mean log count for the 8.2% of samples with detectable E. coli was 1.39 cfu/g. E. coli O157:H7 was isolated from 6/1117 carcases and from 1/560 boneless samples. Salmonella was isolated from 0/1117 carcases and from 3/560 samples of boneless product. Campylobacter sp. were isolated from 4/1117 carcases and from 1/560 boneless samples. Coagulase positive staphylococci were isolated from 23.4% to 32.7% of carcases and boneless Sheep Meat samples, respectively, with positive samples having a mean log count of 0.93 cfu/cm2 and 1.14 cfu/g, respectively. The low level of bacteria described here is consistent with a very low risk to human health due to bacterial hazards in Australian Sheep Meat.
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Microbiological quality of Australian Sheep Meat.
Journal of food protection, 2001Co-Authors: David Phillips, John Sumner, Jodie F. Alexander, Kym M. DuttonAbstract:Microbiological quality of Sheep carcasses and boneless Sheep Meat produced in Australia was surveyed during the period June to November 1998. Sponge samples were collected from 917 carcasses, and Meat samples were drilled from 467 cartons of frozen boneless Meat. Carcass and boneless Meat samples were respectively collected from 7 and 10 establishments that concentrated on export, and from 36 and 5 establishments supplying the Australian domestic market of which 31 were very small plants slaughtering cattle and Sheep but no more than 1,200 Sheep equivalents per week. The mean log total viable counts were 3.55/cm 2 and 3.30/g for carcasses and boneless Meat, respectively. Escherichia coli was detected on 29.2% of carcasses and 24.5% of boneless Meat samples and coagulase-positive staphylococci on 24.1% of carcasses, and 38.6% of boneless Meat samples. Salmonella was detected on 0.1% of carcasses and 1.3% of boneless Meat samples. E. coli O157:H7 was recovered from 0.7% of carcasses and 1.3% of boneless Sheep Meat. There were statistically significant differences between establishment types for some microbiological criteria, although there were no significant differences in prevalence of Salmonella or E. coli O157:H7 between establishment types. While there were differences in sampling and microbiological techniques between this study and another conducted in 1993 to 1994 that require detailed consideration, there were small but significant improvements in several microbiological criteria for boneless Meat. While data that would allow for comparison of carcass data were not gathered, it is unlikely that improvements in the microbiological quality of boneless Sheep Meat could accrue without improvements to carcasses.
