Australian Sheep Meat Research Articles

A risk profile of the Australian red meat industry: Approach and management

A risk profile of microbial, chemical and physical hazards across the supply continuum for the Australian beef, sheep and goat meat industries was developed. The aim was to provide risk managers with a risk rating of hazard:meat and meat product combinations, advise on the feasibility and advisability of risk analyses and identify research and development priorities. Hazard:red meat combinations arising from manufacturing and catering settings that have been associated with food-borne illness and their risk ranking are reported elsewhere. The profiling process was completed within a one-year timeframe and involved a planned iterative consultation process between risk managers and assessors to ensure outputs remained relevant to current risk management concerns.

Pass-Through Elasticity, Substitution and Market Share: the Case for Sheep Meat Exports

This paper empirically examines the exchange rate pass-through elasticity, using sheep meat exports from the two major exporters, Australia and New Zealand. The results show the coexistence of incomplete and complete pass-through in the international sheep meat industry. The Australian sheep meat exporters have a relatively smaller market share than New Zealand and are not able to exercise monopoly power. New Zealand producers, on the other hand, can increase their mark-ups in those destination countries where they have a large market share.

Lamb and sheep meat eating quality — industry and scientific issues and the need for integrated research

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.

Critical control points for meat quality in the Australian sheep meat supply chain Critical control points for meat quality in the Australian sheep meat supply chain

The sheep meat eating quality research program has identified a number of outcomes and critical control points in the supply chain from live sheep genetics to cooked meat. The critical control points, which are largely independent of each other, can be translated into quality management systems to increase average eating quality of all cuts and lower variability. The choice of sire was a critical control point in that selecting for high growth rate and muscling can adversely affect eating quality. The challenge is to make sure that high yield traits are not promoted at the expense of eating quality. Animal age was a critical control point but it was clear that the definition of hogget could be revised to include slightly older animals with teeth in eruption but not in wear. Moreover, M. longissumus dorsi from older animals had only slightly lower eating quality than that from lamb such that this cut could be positioned as a premium product at all maturities, complementing the universally tender muscle psoas major. There was no doubt, however, that over all muscles, lamb remained the premium product. The critical control point for nutrition is that it be adequate, typically to ensure growth of at least 50 g/animal.day. Meat quality is improved through higher glycogen concentrations in muscles at slaughter, higher intramuscular fat content, and possibly reduced collagen crosslinking. Critical control points between muster and slaughter are more difficult to define but are generally aimed at stress reduction to minimise occurrence of the high ultimate pH condition. They include avoiding temperature extremes, loud noises and use of dogs, implementation of good lairage design and the use of skilled animal handlers. Stress is best monitored by ultimate pH measurements in abattoirs, rather than at remote points down the supply chain. After slaughter, the use of electrical stimulation to accelerate post mortem glycolysis is a critical control point. Its use is indicated where 2 conditions are simultaneously met: carcasses are Achilles-hung throughout processing, and the meat is destined for early consumption, as would normally be the case for the domestic market. By accelerating glycolysis, the temperature at rigor can be optimised for rapid tenderisation of low-connective tissue muscles through ageing. The alternative to electrical stimulation of these muscles for the local market is Tenderstretch hanging where rapid ageing is less temperature dependent. Where electrical stimulation is applied the monitoring of its effects with a temperature probe and a pH metre is a critical control point. Even where stimulation is not applied, measurement of average muscle temperature and pH is useful for defining any process. This is because the first 24 h after slaughter sets the scene for later meat storage/distribution, which has its own critical control point: the temperature at which meat is held between abattoir and consumption. Where meat is destined for early sale, the temperature of processing and storage can and should be higher than where the meat is destined for long-term storage as in export markets. For early sale, rapid ageing to optimum eating quality is promoted by higher temperature (2–4°C), whereas for export sale, very cool meat will slowly age in the weeks before consumption while at the same time minimising spoilage and maximising display life. Thus, matching the time–temperature profile of processing and storage to a particular market is a critical control point. The retail end of the supply chain has its own control points, principally display temperature and choice of display packaging, which have major effects on chilled display life. The cooler the better. Compared with conventional overwrap packs, modified atmosphere packs extend display life by typically 80%. However, these more sophisticated packs cost more and will not suit all domestic retailers. The matching of muscles by age with recommended cooking method is a critical control point at retail for ensuring consumer satisfaction. The challenge is effective communication with consumers and is part of the wider challenge of effectively communicating quality-related information at all links of the supply chain.

Microbiological Quality of Australian Sheep Meat

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/cm2 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.

Microbiological Status of Australian Sheep Meat

Two studies were undertaken to determine the microbiological status of sheep carcass meat and frozen, bulk-packed sheep meat produced in Australia. Samples were collected from 470 sheep carcasses and 415 cartons of frozen sheep trimmings over a period of approximately 12 months. Samples were collected from plants processing sheep carcasses for domestic or export markets. On carcasses, where bacterial counts were obtained, the mean of the log10 aerobic plate count (APC) was 3.92/cm2, the geometric mean of the most probable number (MPN) per square centimeter of Escherichia coli (biotype I) was 23, and the geometric mean of the coliform count was 38 MPN per cm2. A high percentage (75%) of samples was positive for E. coli (biotype I), 81% were positive for coliforms, 5.74% were positive for Salmonella spp., and 1.29% were positive for Campylobacter. Bacterial counts were higher on carcasses chilled over a weekend than on carcasses chilled for 24 h. The total number of bacteria on carcasses processed for domestic markets was similar to that on carcasses processed for export markets. E. coli O157 was not isolated from any of the 465 samples tested. Of the frozen export samples that tested positive, the mean of the log10 APC was 3.47/g, the geometric mean of the E. coli (biotype I) count was 9 MPN per g, and the geometric mean of the coliform count was 19 MPN per g. Of the frozen export samples tested, 48% were positive for E. coli (biotype I), 58% were positive for coliforms, and 6.5% were positive for Salmonella spp. E. coli O157 was recovered from 1 of 343 frozen sheep meat samples tested (0.29%). Bacterial counts were higher on samples of domestic product than on samples of export product. Results from both surveys are compared with data from similar studies conducted in other countries.

Comparative performance of South Australian Merino and Poll Dorset × Merino ewes mated to Suffolk rams

Reproductive performance of Poll Dorset × South Australian Merino (PD × M) ewes was superior to that of South Australian Merino (M) genotype with 10% more pregnant ewes, 11% more lambs born per pregnant ewe, and a 7% better lamb survival rate. This resulted in 22 more lambs slaughtered per 100 ewes exposed. Merino ewes produced more greasy wool (6.08 vs. 4.35 kg) of finer fibre diameter (27.5 vs. 32.9 μm) than PD × M ewes. Mature liveweight at mating of PD × M ewes was 17% more than that of M ewes (57.8 vs. 50.1 kg). Carcasses of lambs from PD × M ewes were heavier (18.7 vs. 16.8 kg), shorter per unit carcass weight (698 vs. 783 mm carcass length per 16.9 kg carcass weight), and fatter (13.0 vs. 11.6 mm; GR fat depth) when evaluated at similar carcass weight as compared with carcasses of lambs from M ewes. Skin weight and skin wool characteristics of lambs were similar between genetic groups. Under 1987 and 1988 Australian wool and sheep meat market price conditions, the economic worth of M ewes per unit metabolic weight (mature weight 0.75) was 45% more profitable than that of PD × M ewes.