Eva Wiklund

Game and venison - meat for the modern consumer

This review focuses on how game meat from southern Africa and venison that are increasingly being imported into Europe and the US addresses consumer issues as pertaining to production (wild, free range or intensive production) and harvesting methods, healthiness (chemical composition, particularly fatty acid composition), and traceability. Although African game meat species are farmed extensively, deer species are farmed using extensive to intensive production systems. However, the increasingly intensive production of the cervids and the accompanying practices associated with this (castration, velvetting, feeding of balanced diets, etc.) may have a negative impact in the near future on the consumers perception of these animals. These alternative meat species are all harvested in a sustainable manner using acceptable methods. All these species have very low muscle fat contents consisting predominantly of structural lipid components (phospholipid and cholesterol) that have high proportions of polyunsaturated fatty acids. This results in the meat having desirable polyunsaturated:saturated and n-6:n-3 fatty acid ratios. The South African traceability system is discussed briefly as an example on how these exporting countries are able to address the requirements pertaining to the import of meat as stipulated by the European Economic Community.

Small heat shock proteins and their role in meat tenderness: A review

The eating quality of meat is a result of complex interactions between the biological traits and biochemical processes during the conversion of muscle to meat. It was hypothesised that muscles inevitably engage towards apoptotic cell death due to the termination of oxygen and nutrient supply to the muscle following exsanguination. Thus, factors that regulate the process of apoptotic cell death of muscle cells are believed to ultimately influence meat quality. Proteomic studies have associated the regulation of small heat shock proteins (sHSPs) with various meat quality attributes including tenderness, colour, juiciness and flavour. Due to the anti-apoptotic and chaperone functions of sHSPs, they are proposed to be involved with the eating quality of meat. In this review, we discuss the possible chaperone and anti-apoptotic role of sHSPs during the conversion of muscle to meat and consider the repercussions of this on the development of meat tenderness.

Consumer evaluation of venison sensory quality: effects of sex, body condition score and carcase suspension method.

Intact fallow bucks (n=20) and non-pregnant fallow does (n=24) (Dama dama), in the body condition score (BCS) of 2, 3 and 4 (lean, prime and fat) and rising 2 year old red deer stags (n=26) (Cervus elaphus) of the same BCS range (2-4) were used in this study to determine the impact of sex, BCS and method of carcase suspension on consumer perception of venison quality. Consumers were asked to evaluate cooked meat samples (M. gluteus medius) on an unstructured line scale for colour, flavour, tenderness, juiciness and overall liking. Meat from both fallow deer and red deer was preferred by consumers when carcases had hung by the pelvic suspension (PS) method compared with the Achilles tendon (AT) method of hanging (p<0.001). Consumers also noted a difference in colour between sexes in fallow deer venison, with venison from 36 month-old does being darker (p=0.015), and preferred venison from does over 18-24 month-old bucks. There was a significant difference in the consumer scores for tenderness in red deer stags of BCSs 2 and 4 (p=0.05) with panellists determining BCS 4 animals to be more tender; however no tenderness differences were observed for fallow deer does compared with bucks.

Effect of concentrate feeding on instrumental meat quality and sensory characteristics of fallow deer venison

Venison from twenty four hybrid fallow deer does, 36months old with an initial body condition score (BCS) of 2, was tested to determine the influence of feed type on meat quality. Feeding with concentrates increased BCS (P<0.01) but did not affect ultimate pH (P>0.05). BCS 4 animals had higher intra muscular fat (IMF) (P<0.01), and more tender meat (P<0.05). Venison from does fed over 24weeks exhibited less redness (P<0.01) than those fed for 19weeks regardless of feed type. Panellists evaluated samples for colour, flavour, tenderness, juiciness and overall liking. They detected significantly (P<0.05) stronger flavour in meat from animals fed concentrates. Male panellists detected flavour differences within meat from animals fed concentrates (P<0.05), with longer feeding periods resulting in stronger flavour. There was no difference in overall liking, therefore finishing fallow deer on grain-based concentrate feeds prior to slaughter provided little commercial advantage.

Carcass composition and yield of Alaskan reindeer (Rangifer tarandus tarandus) steers and effects of electrical stimulation applied during field slaughter on meat quality.

Twenty six adult reindeer steers (>3 years old) were used in a study to evaluate the effect of electrical stimulation (ES) on the quality of hot-boned, rapidly frozen shoulder meat and of the striploin (M. longissimus, LD) from carcasses held at +3°C for 48h. Carcass yield and composition was determined from the left carcass half from which the shoulder meat was not removed. The shoulder meat was processed frozen into cubed, sliced or ground products. Proximate composition of the LD, meat color and water-holding capacity were very similar for the ES (n=15) and non-electrical stimulation (NES; n=11) groups. Ultimate pH and shear force values were significantly lower in the ES meat (LD), however a trained sensory panel could not detect differences between the two groups in any of the measured sensory attributes. Consumer preference tests demonstrated that ES increased tenderness in the cubed and sliced products made from field slaughtered reindeer shoulder meat. ES in combination with hot boning and processing of boneless frozen meat can be used in field slaughter systems for reindeer to improve meat quality and to increase the potential value of the carcass.

Effect of pelvic suspension on the instrumental meat quality characteristics of red deer (Cervus elaphus) and fallow deer (Dama dama) venison.

The effect of pelvic and Achilles tendon suspension of red and fallow deer carcasses on meat quality parameters were compared. Venison was evaluated from red deer stags (n=14), bucks (n=14) and fallow deer does (n=10) between 12 and 36months old. Immediately after slaughter, carcasses were split down the dorsal midline and assigned to one of the two hanging methods and pH and core body temperature measured. Twenty-four hours post-slaughter muscles were excised. Venison from fallow deer and red deer stags pelvic-suspended had significantly lower (P<0.001) cooked shear force values than Achilles hung carcasses. There was no significant difference between hanging technique for other characteristics measured. These data indicated that pelvic suspension should be adopted by the deer industry to increase tenderness of venison.

Feeding soy or fish meal to Alaskan reindeer ( Rangifer tarandus tarandus ) – effects on animal performance and meat quality

Fourteen reindeer (8 steers and 6 females) were used to compare the effects of two different reindeer diets (a feed mix based on barley, brome hay and soybean meal (SBM) or fishmeal (WFM) as protein source) on animal growth performance, feed conversion efficiency and ultimate meat quality. Samples from free-ranging reindeer (n=4; 2 steers and 2 females) on the Seward Peninsula were included to provide comparisons with the traditional reindeer meat produced in Alaska. No significant difference was observed in overall weight gain between the WFM and SBM animals or between females and steers; however, the feed conversion efficiency was significantly higher for the reindeer fed the WFM mix. Carcass dressing percentage from the SBM group was higher compared with the WFM animals. No differences were found in live weight, carcass characteristics, meat pH, temperature decline, shear force, meat color or cooking loss when comparing the treatment groups. The meat samples ( M. longissimus ) from the free-range group had the highest amount of omega-3 fatty acids and also the highest amount of polyunsaturated fatty acids (PUFA). Meat from the animals fed SBM was significantly higher in triglyceride content and lower in phospholipid content compared with the two other groups. No significant differences were found when the trained panel compared the sensory attributes of the meat. Off-flavor attributes related to “wild’ or “gamey” flavor was reported by consumers for samples from the WFM and free-range reindeer (15 and 24 per cent of the consumers, respectively). No “fish-related” flavor was reported. In conclusion, no negative effects in either animal performance or meat quality characteristics by using fish meal as opposed to soybean meal as a protein supplement in a milled reindeer diet were found. Abstract in Swedish / Sammandrag: Utfordring av ren med soja- eller fiskmjol – effekter pa tillvaxt, foderutnyttjande och kottkvalitet I var undersokning ingick 14 renar (8 kastrerade sarvar (harkar)och 6 vajor) for att jamfora effekter av tva olika renfoder (baserade pa korn, ho och soja- (SBM) eller fiskmjol (WFM) som proteintillskott) med avseende pa tillvaxt, foderutnyttjande och kottkvalitet. Kottprover fran naturbetande renar (n=4; 2 harkar och 2 vajor) fran Seward Peninsula inkluderades i studien for att representera kvaliteten pa traditionellt producerat renkott fran Alaska. Inga signifikanta skillnader i tillvaxt observerades, varken mellan SBM- och WFM-grupperna eller mellan harkar och vajor. Foderutnyttjandet var dock signifikant battre hos WFM-renarna. Slaktutbytet var hogst for renarna i SBM-gruppen, daremot rapporterades inga skillnader i levandevikt, slaktkroppsegenskaper, pH-varde och temperatur i ytterfilen, skarmotstand, farg eller vattenhallande formaga i kottet nar de tre grupperna av renar jamfordes (SBM, WFM och naturbetande djur). Kottet fran de naturbetande renarna hade det signifikant hogsta innehallet av bade omega-3-fettsyror och av fleromattade fettsyror. Kott fran SBM-renarna hade det hogsta innehallet av triglycerider och det lagsta innehallet av fosfolipider jamfort med de andra tva grupperna. Den tranade smakpanelen kunde inte hitta nagra skillnader i sensoriska egenskaper hos kottet fran renarna i de tre olika grupperna. I en konsumentundersokning rapporterades kommentarer om olika ”vilt-relaterade” bismaker i kott fran naturbetande renar (24% av konsumenterna) och fran WFM-gruppen (15% av konsumenterna), men inga ”fisk-liknande” bismaker i kottet kunde pavisas. Att byta ut sojamjol mot fiskmjol som proteintillskott i renfoder hade inga negativa effekter pa renarnas tillvaxt, foderutnyttjande eller pa renkottets kvalitet.

Muscle biological and biochemical ramifications of farmed game husbandry with focus on deer and reindeer

The deer farming industry in New Zealand and the traditional Sami reindeer husbandry culture in Fennoscandia (Sweden, Norway and Finland) lead the world in commercial venison (deer meat) production from semi-domestic or farmed deer species, i.e. red deer (Cervus elaphus) and reindeer (Rangifer tarandus tarandus), respectively. Production systems are based on natural pastures but include pre-slaughter handling routines and a slaughter process similar to that of domestic species like beef and lamb. Venison has several attributes attractive to consumers – it is tender, has low fat content, a favourable fat composition and high levels of minerals. All these attributes of venison are criteria demanded by today’s discerning meat consumer. The introduction of new venison production routines such as intensive farm-based management, industrialised slaughter and meat processing, use of commercial feed mixtures and possibly new ingredients used to supplement or replace pasture can alter venison quality. One topic of central importance for venison is the image as a natural, free-range origin, clean and healthy product. Care should be taken to ensure the positive image of venison as a ‘natural’ and healthy product is not lost when production systems are intensified to meet the market demand.

Rate of blood loss and timing of exsanguination on prevalence of ecchymosis in fallow deer (Dama dama)

Blood loss associated with four combinations of stunning and exsanguination methods was determined as part of studying prevalence of ecchymosis in slaughtered fallow deer (Dama dama). A fifth treatment simulated incomplete severance of the extended neck after captive bolt stunning. Predicted mean weights of blood collected from the five slaughter treatments, including electrical stunning followed by the thoracic stick method of exsanguination, captive bolt stunning followed by the thoracic stick, captive bolt stunning followed by the gash cut method of exsanguination, electrical stunning followed by the gash cut, and captive bolt stunning followed by incomplete severance of the extended neck, were 1458.7, 1072.7, 684.5, 463.7, and 228.5 g, respectively. The overall effect of exsanguination method was highly significant (p<0.001) with the thoracic stick resulting in the greatest weight of blood collection in the 10s period immediately after initiation. The overall effect of stunning method on blood loss was not significant, although there was a significant (p<0.05) stunning method by exsanguination method interaction. Ecchymosis of varying severity occurred in some carcases from all treatment groups. Using the total loin and round ecchymosis scores, when little or no ecchymosis (grades 0 or 1) was compared with some ecchymosis (grade 2) by logistic regression, castrated bucks were 9.8 times more likely (p=0.002) and does 4.2 times more likely (p=0.06) to have some ecchymosis than entire bucks. The results indicate that ecchymosis can be reduced in fallow deer carcases by thoracic stick exsanguination incorporated less than 10s after stunning.

Does carcass suspension technique influence reindeer (Rangifer tarandus tarandus) meat quality attributes

In total, eight reindeer steers (ages 3-6 years old) were used in the study to evaluate the effects of carcass suspension technique on meat tenderness, colour and water-holding capacity (WHC). Carcasses were split along the spine and sides were randomly allocated to pelvic suspension (hung using a butcher hook through the obturator foramen) or normal Achilles tendon suspension (control treatment). From all 16 carcass halves, meat samples were collected from the loin (M. longissimus), inside (M. semimembranosus) and shoulder (M. triceps brachii) for sensory evaluation and measurements of shear force (tenderness). Loin samples were also evaluated for meat colour at 1 day after slaughter and for purge (WHC) after vacuum-packaged chilled storage (+2C) for 1, 2 and 3 weeks. No significant effects of carcass suspension technique were found for reindeer meat colour and WHC (purge). Shear force values for loin samples from pelvic-suspended carcasses were significantly (P = 0.001) lower than those from Achilles tendon-suspended carcasses, and there was a similar trend for inside samples, although this was not significant (P = 0.06). There was no effect of carcass suspension technique for shear force values of the shoulder samples. The trained panel judged loin and inside samples from pelvic-suspended carcasses to be more tender (P 0.001) while no effect of carcass suspension technique on tenderness was found in the shoulder samples. Juiciness was not affected by carcass suspension. The present study demonstrated that pelvic suspension improved tenderness in the most valuable cuts from the reindeer carcass (loin and inside).