ebook img

The problem of dark-cutting in beef : a seminar in the EEC programme of coordination of research on animal welfare, organised by D.E. Hood and P.V. Tarrant, and held in Brussels, October 7-8, 1980 PDF

484 Pages·1996·35.35 MB·English
Save to my drive
Quick download
Download
Most books are stored in the elastic cloud where traffic is expensive. For this reason, we have a limit on daily download.

Preview The problem of dark-cutting in beef : a seminar in the EEC programme of coordination of research on animal welfare, organised by D.E. Hood and P.V. Tarrant, and held in Brussels, October 7-8, 1980

THE OCCURRENCE, CAUSES AND ECONOMIC CONSEQUENCES OF DARK- CUTTING IN BEEF - A SURVEY OF CURRENT INFORMATION. P.V. Tarrant Meat Research Department, Agricultural Institute, Dunsinea, Castleknock, Co. Dublin, Ireland. ABSTRACT In the ppepa:t'ation of this semin= on stpess in cattle and dapk-eutting in beef, infoPmation vas eo Hected from a wide baekgpound by means of a survey to detemine the ppesent position and pecent deveLopments in this aPea. Questionnaires (see Appendix 1) were sent to senior scientists in meat peseapch LabomtoPies. Twenty-seven compLeted questionnaipes Wepe returned from nineteen aount'Pies 1. Respondents were asked to present the situation as it exists in their own countries. The results represent informed scientific opinion based on research findings and practicaL expePience of the ppobLem in the meat industry. They ppovide a peasonabLe estimate of the extent of the pmHem, in tems of incidence and type of cattle affected, the ppincipLe chapactePistics of the condition and its impact on the meat industpy. In ppesenting the pesuUs, pesponses ape frequently identified on a nationaL basis. This was found to add considembLy to the usefuLness of the data. Howevep, it is necessary to emphasise that the infol'm'J.tion ppese-nted in any particuZ-ar case does not necessarily represent the national position, but pathep a ppevaiUng situation within each eountPy. In assessing the resuLts, aU pepUes were given an equaL weighting. Australia, Belgium (2), Britain, Bulgaria, Canada, Czechoslovakia, Denmark, France, Finland, West Germany, Ireland, The Netherlands, New Zealand, Norway, Poland (2) r South Africa, Sweden, The United States (Maryland, Illinois, Missouri, Wyoming, Texas (2), Oregan) and Yugoslavia. D. E. Hood et al. (eds.), The Problem of Dark-Cutting in Beef © ECSC, EEC, EAEC, Brussels-Luxembourg 1981 The principal results of the survey follow and the detailed results are presented in Appendix 2. Question: What sectors of the beef trade have problems associated with dark-cutting? The sectors of the beef trade most widely considered to have p~oblems associated with dark-cutting are the Cdrcass sector, vacuum-packed primal sector and retail fresh beef sector. All the other sectors of the trade which were listed in the questionnaire, (see Appendix 1) were occasionally consid- ered to have problems with dark-cutting beef. Question: What category of animal is affected? Young bulls are universally. considered to be affected by dark-cutting, whereas opinions regarding the other sex cate- gories were divided. In steer-producing countries, in general, all categories of cattle were considered to be affected. In countries with substantial bull beef production, dark-cutting is predominantly associated with young bulls and other cate- gories were not frequently thought to be affected. Question: Is there a breed effect? There is a lack of information concerning the effect of breed on the incidence of dark-cutting in beef. Question: Can you estimate the incidence of dark-cutting? Estimates of incidence varied. The incidence was most frequently estimated at 1 - 5 per cent for steers and heifers, 6 - 10 per cent for cows and 11 - 15 per cent for young bulls. Question: What muscles are most liable to be affected? M. Longissinm.s dorsi was universally considered to be one of tne muscles most liable to be affected. Other muscles were much less frequently cited. These tended to be the major hindquarter muscles more often than forequarter muscles. Question: What ultimate pH values (measured in M. 1. dorsi) would indicate dark-cutting to you? Beef quality deteriorates when the ultimate pH value is equal to, or above, 5.8. The precise value at which a carcass is deemed 'dark-cutting' depends largely on processing and marketing factors and is in the range pH 5.8 - 6.3. Values above this range are always associated with an unacceptable degree of dark, firm, dry (DFD) beef. Question: Is there a seasonaZ effect? If your answer is ryes I, please indicate in which months dark-cutting is most likely. A majority of respondents reported a seasonal effect. These respondents were mainly from the traditional steer-prod- ucing regions. There was considerable agreement concerning which months are most frequently associated with incidence or intensity of DFD. In the northern hemisphere, these are Sept- ember to January, inclusive, and the month of April. PZease suggest three causes of dark-cutting in your' country in order of importance. Mismanagement of cattle before slaughter, resulting in physiological stress and exhaustion, was the most frequently suggested cause of dark-cutting in beef. In particular, the practice of penning cattle together in mixed lots at the abbatoir, and unsuitable transport conditions, were often cited. The other causes suggested concerned climatic conditions, nutrition, path- ological conditions, genetic factors and stress in general. Question: What do you think are the main objections to dark-cutting beef? There was general agreement that abnormal colour and spoilage characteristics are the main reasons for objecting to DFD beef. The appearance, consistency and organoleptic characteristics of the meat are also considered to be object- ionable. Question: Is theY'e an economic penaUy foY' daY'k-cutting beef at any stage in the m=keting chain? If so, what is the economic Zoss relative to a normaZ carcass or meat out? A majority of replies indicated that there is an economic penalty. The economic loss relative to normal meat was most frequently put at 10 per cent. ~ch higher losses were occasionally reported. Question: Is theY'e down-gY'ading of caY'Casses on a national, Y'egional or local classification or grading scheme? Down-grading of dark-cutting carcasses at beef classific- ation or grading is fairly common and was reported by 44 per cent of respondents. Question: Are there other economic consequences? Rejection of DFD beef at various stages of the marketing cnain was the principle area of concern. Cost of -disposal of DFD beef and substituting normal meat, loss of reputation for quality and down-grading of non-affected cuts were also cited as additional economic consequences. CONCLUSIONS The survey confirms that dark-cutting is a persistent condition in cattle, occurring in all categories of cattle and in all countries surveyed. Conclusions relevant to the subjects of meat quality and animal welfare can be drawn and these will be considered separately. Meat quality The results of the survey show that dark-cutting beef is rejected by the meat industry and by the consumer on the basis of a number of serious quality faults. These are such as to exclude its use in normal fresh meat products. The frozen beef trade is a possible outlet. However, the reduced organoleptic characteristics of the product raise the question whether such meat can be diverted into frozen beef outlets, particularly the home freezer market, without long-term repercussions. The estimated incidences (Table 4, Appendix 2) show that the condition is of considerable proportions in many of the countries surveyed. The reported high variability in the daily incidence makes detection and control by industry more difficult. For example, the seasonal effect in Ireland is estimated to cause a four-fold increase in the average incidence and this is made up of a highly variable daily incidence. Young bulls were, predictably, reported to have the highest incidence. The meat industry itself has control over the major causes of dark-cutting in these animals, which concern pre-slaughter management procedures. Proper control of penning and handling procedures at abattoirs would greatly reduce the incidence in young bulls and other cattle from intensive product- ion systems. As it is often economically more favourable to produce beef from bulls rather than steers, it is clearly impor- tant for the industry to minimise meat quality defects in bull beef. The acceptability of beef of abnormal ultimate pH is greatly influenced by production and trading circumstances. There is scope for the preparation of a comprehensive pH stand- ard for use in quality control and quality assessment. Measure- ment of ultimate pH is widely practised and pH standards vary considerably, to meet particular production and marketing circumstances. A suitable pH standard for use within" the European Community would take into account the type of carcass under examination and the process and market for which it is intended. In this context it is important to emphasise the wholesomeness of dark~cutting beef, despite its technological and organoleptic disadvantages. Substantial economic penalties were widely reported. These may serve as an impetus towards developing practical procedures aimed at reducing the incidence and improving the methods of detection. Suitable procedures should be developed for utilising DFD beef. Any attempt to market DFD as normal beef should be discouraged in the long-term interests of the industry. Animal Welfare The dark-cutting condition is relevant to animal welfare because it results from exposure to stress and is indicative of physical exhaust10n before slaughter. The condition is unknown in well-fed and rested animals. Some categories of cattle are more likely to be affected than others. This may be due to inherent sex characteristics as in the case of young bulls. Alternatively, in the case of cows, it may be due to lower standards of care before slaughter. The difficulty of inducing dark-cutting experimentally, e.g. by fasting, exercise or similar stressors, has been reported in the literature. It follows that the observed incidence of dark-cutting underestimates the number of cattle exposed to stress before slaughter. The observed incidence of dark-cutting represents only the most severely stressed animals. From the point of view of animal welfare, young bulls should be considered apart from the other categories of cattle. The high incidence of dark-cutting in these animals is assoc- iated with the sex characteristics of an excitable temperament and aggressive or sexual activity. These activities are more pronounced in a novel environment and, although stressful, represent normal animal behaviour. Dark-cutting in these animals does not necessarily indicate ill treatment before slaughter. Dark-cutting was attributed to severe environmental stress factors, sometimes potentiated by genetic factors. The causes reported in the survey are obviously the most common ones. In practice, any situation which results in substantial depletion of muscle glycogen reserves will cause dark-cutting if the animal is slaughtered before recovery takes place. The mechanisms of muscle glycogen depletion are (a) the performance of heavy muscular work resulting in an increased intra-cellular energy demand, (b) adrenergic activation of glycogenolysis by increased adrenaline concentration in the circulation, and (c) long-term depletion of glycogen reserves as a consequence of inanition. Because of the frequency with which mismanagement of cattle before slaughter was cited as a cause of dark-cutting, the results suggest that there is a need for further information concerning procedures for handling and transport of cattle. Standards must be agreed upon and made available to cover the various situations which exist in the industry. The construction of pens and their method of use would appear to require partic- ular attention. The recommended holding time for the different categories must be clarified, together with procedures for allowing exhausted cattle to recover before slaughter. The results suggest that the climate and other seasonal factors are important in the aetiology of the dark-cutting condition. Exposure to the elements and inadequate nutrition obviously occur, particularly in extensive beef production systems, and the consequences are apparent in the carcass. Alleviation of animal suffering due to seasonal factors is a more difficult proposition than is the case with pre-slaughter factors. ACKNOWLEDGEMENTS Information was kindly provided by the following persons: Dr. A.J. Bailey, United Kingdom; Dr. H.F. Bernholdt, USA; Ir. H. de Boer, the Netherlands; O.S. Braathen, Norway; Mrs. L. Buchter, Denmark; Canada Packers Ltd., Canada; 10 Ir. M. Casteels, Belgium; Dr. B. Chrystall, New Zealand; Dr. E. Cosentino, Italy; Dr. C.L. Davey, New Zealand; Dr. T.R. Dutson, USA; Dr. R.A. Field, USA; Eng. Geraldo Cia, Brazil; Dr. Maria Gorna, Poland; Dr. H.B. Hedrick, USA; Ing. J. Jedli~ka, Czechoslavakia; Dr. D.E. Hood, Ireland; Prof. Dr. E. Kallweit, Federal Republic of Germany; Dr. W.H. Kennick, USA; Dr. A.W. Kotula, USA; Dr. K. Krzywicki, Poland; Dr. G. Monin, France; Dr. R. Naude, South Africa; Prof. Dr. N. Nestorov, Bulgaria; Prof. F.P. Niinivaara, Finland; Prof. Dr. H. Pfeiffer, German Democratic Republic; E. Puolanne, Finland; Dr. S. Rahelic, Yugoslavia; H. Ruderus, Sweden; Prof. Dr. L. Sch8n, Federal Republic of Germany; Dr. G.C. Smith, USA; Prof. N.M. Tulloh, Australia; Prof. Dr. J. van Hoof, Belgium; Dr. D.J. Walker, Australia; Dr. Maria Vada, Hungary. II APPENDIX 1 QUESTIONNAIRE DARK-CUTTING IN BEEF Please tick (thus I) the box on the questionnaire that best expresses your opinion of the situation in your country or region. Where appropriate more than one box may be ticked. Please give additional information which you consider to be relevant to this subject. Please give the country or general region to which your answers apply: 1. What sector(s) of the beef trade in your country or region has (have) problems associated with dark-cutting: D D D D 0 0 D Carcass Vac-pack Retail Ground Cured/ Fermented Other trade fresh beef fresh beef salted products (please primals beef products specify COMMENT: 2. What category of animal is affected: D D 0 0 0 0 Steer Heifer Cow Young bull Other All (castrate) (virgin) (lactating) (entire) (specify) categories if +0 ~ if COMMENT: 3. Is there a breed effect? o D o Yes No Don't know If 'yes', what breeds'are most susceptible: 12 4. Can you estimate the incidence of dark-cutting: Don't o 1-5% 6-10% 11-15% 16-20% 20%+ know Steer Heifer Cow Young bull i i All categories ~ i ADDITIONAL COMMENTS: 5. What muscles are most liable to be affected: 1~. biceps femoris M. sem~memb.~anosus M. trapezius M. psoas major M. 8em1.- terU1:z.nosus M. infraspinat" 8M. gLuteus medius BM. longissimus dorsi § M. supraspinat" ,~. adductor - M. triceps brachii Other muscles or meat cuts, please specify: 6. What ultimate pH values (measured in M. L. dorsi) would indicate dark-cutting to you: U 0 i_I D U 0 0 0 pH 5.7 5.8 5.9 6.0 6.1 6.2 6.3 6.4 COMMENT:

See more

The list of books you might like

Most books are stored in the elastic cloud where traffic is expensive. For this reason, we have a limit on daily download.