Effects of animal age on the eating quality of sheep meat

2005 ◽  
Vol 45 (5) ◽  
pp. 491 ◽  
Author(s):  
D. W. Pethick ◽  
D. L. Hopkins ◽  
D. N. D'Souza ◽  
J. M. Thompson ◽  
P. J. Walker

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.

2005 ◽  
Vol 45 (5) ◽  
pp. 517 ◽  
Author(s):  
D. W. Pethick ◽  
R. Davidson ◽  
D. L. Hopkins ◽  
R. H. Jacob ◽  
D. N. D'Souza ◽  
...  

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 × 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.


2005 ◽  
Vol 45 (5) ◽  
pp. 499 ◽  
Author(s):  
D. L. Hopkins ◽  
P. J. Walker ◽  
J. M. Thompson ◽  
D. W. Pethick

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 × (Border Leicester × Merino) (second cross unweaned lambs, mixed sex, 3–5 months of age); Poll Dorset × (Border Leicester × Merino) (second cross weaned lambs, mixed sex, 9–12 months of age); Border Leicester × Merino (BLM; first cross weaned lambs, mixed sex, 9 months of age); Poll Dorset or White Suffolk × Merino (PDM; first cross weaned lambs, wethers, 12 months of age); Merino × Merino (weaned wether lambs, 9–12 months of age); Border Leicester × Merino (BLM; first cross hoggets, mixed sex, 20 months of age); and Poll Dorset or White Suffolk × 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.


2020 ◽  
Vol 49 (6) ◽  
pp. 1158-1173
Author(s):  
E Moholisa ◽  
P.E. Strydom ◽  
I Van Heerden ◽  
A Hugo

Feeding systems and other factors associated with processing influence meat quality, and therefore sensory attributes. This study was conducted to assess the meat quality attributes of young grain-fed and older grass-fed steers that mostly affect consumer acceptability of beef. Eighty Bonsmara steers consisting of 20 each of A-age (0-tooth) grain-fed (AC) and grain-fed supplemented with zilpaterol (AZ), 20 each of grass-fed AB (1-2 teeth) and B-age (3 - 6 teeth) animals were used. This combination represented the typical feeding systems of South Africa and other countries using similar classification systems, therefore describes the typical feeding systems of the South African beef industry. The longissimus lumborum (LL), semitendinosus (ST), and biceps femoris (BF) muscles were tested for colour, moisture properties, lipid oxidation and sensory attributes. It was found that diet in combination with animal age influenced meat colour. Muscles of the older grass-fed steers were generally darker and duller (darker red) compared to muscles of young grain-fed animals. Moisture loss was consistently higher in zilpaterol supplemented meat samples compared to the feedlot controls, while muscles of the grass-fed animals had lower moisture loss. A sensory panel clearly distinguished between cuts of grain-fed (AZ and AC) and grass-fed carcasses (AB and B) on the grounds of flavour characteristic. The AB and B cuts scored higher for grassy, animal-like and rancid flavour overtones and lower for roasted flavour and sourness than AZ and AC grain-fed cuts. This indicated that typical flavours related to diet define expected eating quality. Keywords: age, grain, grass, meat quality, zilpaterol


1998 ◽  
Vol 66 (2) ◽  
pp. 329-340 ◽  
Author(s):  
K. D. Sinclair ◽  
A. Cuthbertson ◽  
A. Rutter ◽  
M. F. Franklin

AbstractAn experiment was devised to examine the effect of animal age at slaughter, within genotype and finishing system, on bull beef eating quality characteristics to assess the 15 month age limit imposed for bulls at slaughter by the Meat and Livestock Commission specification for improved beef eating quality. The experiment was a factorial design using bulls of two crossbred genotypes (Aberdeen Angus × and Charolais ×), offered two diets (silage-based and barley-based) and slaughtered at two abattoirs. Bulls were slaughtered from approximately 10 months of age on seven dates (ages) at 6-week intervals. Bulls given barley were slaughtered on date numbers 1 to 5 (43 to 67 weeks of age) and bulls given silage on date numbers 2 to 7 (49 to 79 weeks of age). On each slaughter date and at each abattoir the first four commercial steers which followed the bulls on the slaughterline and met the United Kingdom (UK) modal carcass specification R 4L were selected as abattoir, slaughter date and industry representative controls. At 48 h post mortem samples of m. longissimus lumborum; m. biceps femoris; and m. semimembranosus were recovered from all bull and steer carcasses, vacuum packed and stored at 2°C for a fiirther 12 days before freezing and subsequent assessment by a 12 member taste panel and texture analysis using a Warner Bratzler shear jig.Bulls achieved high growth rates during the finishing period averaging 1·22, 1·55, 1·41 and 1·98 kg/day for silage-fed Angus × bulls; barley-fed Angus × bulls; silage-fed Charolais × bulls; and barley-fed Charolais × bulls, respectively (s.e.d. = 0·08; P < 0·05). Age at slaughter had no significant effect on beef tenderness from young bulls in this study. Similarly, no significant differences in beef tenderness either between genotypes or diets were detected. Bulls, however, produced meat which had lower mechanical shear force values (10·2 v. 11·9 kg for m. biceps femoris; P < 0·001) and was considered to be more tender (P < 0·001), less flavoursome (F < 0·001) and more acceptable (P < 0·01) than that produced by steers.It was concluded that beef aged for 14 days post mortem and recovered from young bulls which have achieved high growth rates can be at least as good as that representative of the UK standard product. The 15-month age limit for bulls ensures that commercially produced bulls achieve high lifetime growth rates and will produce beef of a quality comparable with that achieved in this study.


2001 ◽  
Vol 72 (1) ◽  
pp. 87-94 ◽  
Author(s):  
B. Lebret ◽  
H. Juin ◽  
J. Noblet ◽  
M. Bonneau

AbstractThe aim of this study was to investigate the effects of a 30-day increase in age of pigs slaughtered at 110 kg body weight (BW) on carcass and m. longissimus dorsi (LD) and m. biceps femoris (BF) traits, and meat sensory quality. A total of 60 pigs from two genotypes: synthetic line ✕ (Large White ✕ Landrace) (SL) and Duroc ✕ (Large White ✕ Landrace) (D) were used, each genotype containing five groups of six littermates (three castrated males and three females). At the average BW of 30 kg, littermates of the same sex were allocated to three groups. Pigs of group AL were offered ad libitum a standard growing-finishing diet (13·6 MJ/kg digestible energy, 9·5 g/kg of lysine) from 30 up to 110 kg BW. The R1 pigs received the same diet at 0·75 of the ad libitum intake of their AL littermates. The R2 pigs were submitted to both energy and protein restrictions in order to get the same growth rate as the R1 pigs and the same body composition as the AL pigs. Results were similar in both genotypes. In agreement with the protocol, age at slaughter was increased by 30 days in R1 and R2, and AL and R2 pigs had comparable carcass composition. Compared with AL, average daily gain was decreased in R1 and R2 pigs, and food efficiency was decreased in R2, but remained unaffected in R1 pigs. Intramuscular fat (IMF) concentration was decreased in the R1 pigs, especially in BF (15·5 v. 19·7 mg/g), while it was increased in the LD of the R2 pigs, particularly in the D animals (24·2 v. 17·4 mg/g), compared with AL pigs. Meat quality parameters (rate and extent of pH fall, reflectance and drip loss) were similar in the three feeding regimens. The taste panel did not find any significant difference between feeding regimens for tenderness, juiciness, flavour, flour sensation after mastication and mouth coating of the meat, despite the differences reported in IMF concentration. This suggests that, for the genotypes used in this experiment, an increase of 30 days in the age at slaughter greatly influences the carcass and/or the muscle chemical composition, depending on the feeding strategy applied to reduce the growth rate but does not strongly modify the meat eating quality.


Foods ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 332 ◽  
Author(s):  
Lees ◽  
Konarska ◽  
Tarr ◽  
Polkinghorne ◽  
McGilchrist

Actinidin is a cysteine protease enzyme which occurs in kiwifruit and has been associated with improved tenderness in red meat. This study evaluated the impact of actinidin, derived from kiwifruit, on consumer sensory outcomes for striploin (M. longissimus lumborum) and outside flat (M. biceps femoris). Striploins and outside flats were collected from 87 grass-fed steers. Carcasses were graded to the Meat Standards Australia (MSA) protocols. Striploins and outside flats were then dissected in half and allocated to one of the following two treatments: (1) not infused (control) and (2) infused with a kiwifruit extract (enhanced), and then prepared as grill and roast samples. Grill and roast samples were then aged for 10 or 28 days. Consumer evaluations for tenderness, juiciness, flavor, and overall liking were conducted using untrained consumer sensory panels consisting of 2080 individual consumers, in accordance with the MSA protocols. These scores were then used to calculate an overall eating quality (MQ4) score. Consumer sensory scores for tenderness, juiciness, flavor, overall liking, and MQ4 score were analyzed using a linear mixed-effects model. Kiwifruit extract improved consumer scores for tenderness, juiciness, flavor, overall liking, and MQ4 scores for striploins and outside flat (p < 0.05). These results suggest that kiwifruit extract provides an opportunity to improve eating experiences for consumers.


2005 ◽  
Vol 45 (5) ◽  
pp. 561 ◽  
Author(s):  
J. M. Thompson ◽  
D. L. Hopkins ◽  
D. N. D'Souza ◽  
P. J. Walker ◽  
S. R. Baud ◽  
...  

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).


Author(s):  
Z Pietrasik ◽  
Phyllis J Shand

Abstract Several muscles from mature beef carcasses have been identified as failing to provide adequate tenderness required for a satisfactory consumer eating experience. Postmortem processing strategies can help improve the tenderness and subsequent eating quality of mature beef muscles. The current study was undertaken to investigate the impact of processing strategies (blade tenderization [BT], pre-tumbling [PT], and moisture enhancement [ME]), alone and in combination, on processing yield and eating quality-related parameters of selected loin and hip muscles (gluteus medius [GM], longissimus lumborum [LL], semimembranosus [SM], and biceps femoris [BF]) from youthful and mature beef cattle. Results indicate that muscles from mature beef were inherently less tender (P &lt; 0.05), but some tenderization procedures produced meat that was similar in tenderness to that of youthful cattle. Of the different tenderization strategies evaluated, BT followed by ME (injection of a salt/phosphate solution) was the most effective strategy for improving (P &lt; 0.05) tenderness of tougher muscle cuts such as BF and SM. Moisture enhancement alone improved tenderness (P &lt; 0.05) and juiciness (P &lt; 0.01) of SM, GM and LL, but with the exception of samples tenderized prior to injection, was not effective (P &gt; 0.05) in BF muscles. No additional tenderization of GM and LL samples was observed (P &gt; 0.05) by combining PT or BT with ME. Combining PT or BT with ME; however, was effective (P &lt; 0.05) to control the increased purge loss observed following ME treatment in SM and LL muscles. Pre-tumbling as a single treatment was ineffective (P &gt; 0.05) in all of the muscles, and only treatments that included BT were sufficient to affect an increase (P &lt; 0.05) in tenderness of BF.


Foods ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 529 ◽  
Author(s):  
Rachel A. O’Reilly ◽  
Liselotte Pannier ◽  
Graham E. Gardner ◽  
Andrea J. Garmyn ◽  
Hailing Luo ◽  
...  

Along with animal production factors, it is important to understand whether demographic factors influence untrained consumer perceptions of eating quality. This study examined the impact of demographic factors and sheepmeat consumption preferences on eating quality scores of American, Australian and Chinese untrained consumers. M. longissimus lumborum (LL) and m. semimembranosus (SM) were grilled according to sheep Meat Standards Australia protocols and evaluated by 2160 consumers for tenderness, juiciness, flavour and overall liking. Linear mixed effects models were used to analyse the impact of demographic factors and sheepmeat consumption habits on eating quality scores. Consumer age, gender, number of adults in a household and income had the strongest effect on sensory scores (P ≤ 0.05), although, the impact was often different across countries. Frequency of lamb consumption had an impact on sensory scores of American, Australian and Chinese consumers but larger sample sizes in some underrepresented subclasses for Australian and Chinese consumers are needed. Results suggest it is important to balance sensory panels for demographic factors of age, gender, number of adults and income to ensure sensory preferences are accurately represented for these particular populations.


2021 ◽  
Author(s):  
Kyle T Mahagan ◽  
Andrea J. Garmyn ◽  
Jerrad F. Legako ◽  
Mark Miller

A consumer study was conducted to determine if consumers scored beef palatability traits differently on paper vs. digital ballots. Beef subprimals were collected to represent four treatments with inherent variation in eating quality: USDA Select eye round aged 7 d postmortem, USDA Select strip loin aged 7 d postmortem, USDA Choice tenderloin aged 21 d postmortem, and USDA Prime strip loin aged 21 d postmortem. Accessory muscles, external fat, and connective tissue were removed from subprimals. Muscles were fabricated into 2.5 cm steaks and further divided into 2 equal halves for consumer testing. Consumers (n = 360) were served eight samples divided into two blocks representing the two ballot types. Select longissimus lumborum samples were always served in the first and fifth position to start each ballot block, with the remaining three treatments served in a randomized order between the latter three positions within each ballot block. Consumers rated each steak sample for tenderness, juiciness, flavor liking, and overall liking on either a paper or digital ballot, and then rated the paired steak halves on the opposite ballot during the second block of sample testing. Ballot type influenced (P &lt; 0.02) all traits, as consumers scored tenderness, juiciness, flavor liking, and overall liking greater (P &lt; 0.05) on paper ballots compared to digital ballots, regardless of treatment. The smallest margin between paper and digital ballots was observed for tenderness, where scores only differed by 1.8 units. However, juiciness, flavor liking, and overall liking all differed by 3.4 units in favor of paper ballots. Consumers scored palatability traits greater on paper ballots compared to digital ballots, and these findings were consistent across a range of eating quality outcomes. These results should be considered when comparing past consumer testing results using paper balloting systems to those where digital ballots were used.


Sign in / Sign up

Export Citation Format

Share Document