Meat Shear Force Research Articles

사료내 생균제, 일라이트, 활성탄 및 목초액의 첨가가 육계의 성장 능력 및 도체 특성에 미치는 영향

본 시험은 육계에 대한 생균제, 일라이트, 활성탄 및 목초액의 사료적 가치를 평가하기 위하여 생균제 0.2%(T1)와 일라이트(T2), 활성탄(T3) 및 목초액(T4)을 각각 1.0%를 broiler 200수에 급여하여 증체량, 사료 섭취량, pH, 전단력, 관능 평가, 육색 및 지방산 함량을 분석하였다. 증체량은 전기 사료 급여 시에 C보다 T1과 T4에서 유의적으로 높았고, 후기 사료 급여 시는 C와 T4보다 T1, T2 및 T3에서 유의적으로 높게 나타났다(P<0.05). 사료 효율은 처리구간에 유의성이 없었다. 계육의 일반 성분 중 수분과 조단백질 및 조회분은 유의성이 없으며, 조지방은 대조구보다 처리구에서 낮은 함량을 보였다. 가열 감량은 T3와 T4에서 낮았으며, 보수성은 T3와 T4에서 높았다. 관능 평가 결과 연도는 C가 가장 높고 T4가 제일 낮아 연도 개선 효과를 보였다. 육색 중 적색도<TEX>$(a^*)$</TEX> 및 황색도<TEX>$(b^*)$</TEX> 값은 모든 처리구에서 차이가 없었으나, 명도<TEX>$(L^*)$</TEX>값은 T1, T2, T3 및 T4에서 대조구보다 높았다(P<0.05). 포화 지방산인 stearic acid 함량은 C보다 T1, T2, T3 및 T4에서 낮았으며, 불포화 지방산인 oleic acid 함량은 대조구보다 처리구에서 높았다(P<0.05). 결론적으로 육계 사료에 목초액을 1% 첨가 급여할 경우 경쟁력 있는 브랜드 계육의 생산이 가능하며, 농가 소득 증대에 크게 기여할 것으로 생각된다. We investigated the effects of dietary supplements of probiotics, illite, active carbon and hardwood vinegar on growth performance, feed intake, and pH, shear force, sensory evaluation, meat color and fatty acid composition of meat in broilers. Two hundred broilers were fed diets for five weeks containing 0.2% of probiotics (T1), and 1% of Illite (T2), 1% active carbon (T3), or 1% hardwood vinegar (T4). Body weight gain was higher in T1 and T4 groups fed the starter diet but was the lowest in C and T4 for finishing period (P<0.05). Feed efficiency was not significantly different. In proximate composition, crude fat content of chicken meat were decreased lower in all treatment groups than control, but moisture, crude protein and crude ash were not significantly different. Cooking loss was decreased in T3 and T4 and WHC (water holing capacity) was increased in T3 and T4 groups compared to the other groups. In sensory evaluation, T4 tended to improve the hardness. Redness <TEX>$(a^*)$</TEX> and yellowness <TEX>$(b^*)$</TEX> were no difference between the all treatment groups, lightness <TEX>$(L^*)$</TEX> were higher in T1, T2, T3 and T4 groups than control group (P<0.05). Stearic acid content was lower in T1, T2, T3 and T4 groups, but oleic acid contents were higher in T1, T2, T3 and T4 groups (P<0.05). These results showed that supplementing broiler diets with 1.0% hardwood vinegar may noticeably improve the meat quality of broiler.

Effect of Chronic Heat Exposure on Fat Deposition and Meat Quality in Two Genetic Types of Chicken

The effects of chronic heat stress on growth, proportion of carcass and fat deposition, and meat quality were investigated in 2 genetic types of chickens. One hundred and eight 5-wk-old male chickens from a commercially fast-growing strain (Arbor Acres, AA) and a locally slow-growing species (Beijing You chicken, BJY) were kept in the following conditions: constant optimal ambient temperature at 21°C and ad libitum feeding (21AL), constant high ambient temperature at 34°C and ad libitum feeding (34AL), and constant optimal ambient temperature 21°C and pair-fed to the 34AL chickens (21PF). The results showed that feed intakes were decreased by heat exposure in both type of chickens at 8 wk of age (P < 0.001). At 34°C, AA broilers exhibited greatly decreased weight gain (22.38 vs. 61.45 g/d for 21AL) and lower breast proportion compared with 21AL, while the relevant indices of BJY chickens were not affected in hot condition. Abdominal fat deposition of BJY chickens was enhanced by heat exposure (P < 0.05). Fat deposition of AA broilers was decreased in heat-exposed and pair-fed chickens. Abdominal and intermuscular fat deposition in 34AL birds, however, were enhanced compared with 21PF birds (P < 0.01). The L* values, drip loss, initial pH, and shear force of breast meat in BJY chickens were not affected by treatments. In AA birds, chronic heat stress increased L* values and drip loss compared with 21AL, but pH and shear force were not affected by treatments. The results from this study indicated that the impact of heat stress was breed dependent and that BJY chickens showed higher resistance to high ambient temperature, which could be related to their increased feed efficiency and deposition of abdominal fat under heat exposure.

Influence of flock treatment with the antibiotic tylosin on poultry meat quality: results of a preliminary experiment

The veterinary antibiotic tylosin was administered to broilers at sub-therapeutic and therapeutic levels to study its effect on the quality of poultry breast meat. No statistically significant differences were observed in moisture content, pH, drip loss, colour and extent of lipid oxidation between the breast meat from treated and not treated birds. However, the cooking loss of the meat from the birds administered tylosin was significantly higher than that from the not treated ones. Additionally, the mean shear force of the breast meat was significantly lower for the sub-therapeutically treated broilers than for the not treated and the therapeutically treated ones. It was concluded that the level at which tylosin was administered to the broilers affected the quality of the breast meat, particularly its textural properties.

Association of CAPN1 and CAST gene polymorphisms with meat tenderness in Bos taurus beef cattle from Argentina

The activity of the calpains/calpastatin proteolytic system is closely related to the postmortem tenderization of meat. We investigated the association between beef tenderness and single nucleotide polymorphism (SNP) markers on the CAPN1 gene (SNP316, alleles C/G; SNP530 alleles A/G) and the CAST gene 3' untranslated region (SNP2870, alleles A/G). We sampled nine slaughter groups comprising 313 steers which had been reared in beef production systems in Argentina between 2002 and 2004 from crosses between Angus, Hereford and Limousin cattle. Minor allele frequencies for the markers were 0.27 to 0.46 (C), 0.02 to 0.18 (A), and 0.24 to 0.53 (A), respectively. The presence of CAPN1 markers had significant effects on meat shear force but no detectable effects were demonstrated for the CAST marker. The shear force of meat from steers with the SNP316 CC genotype was 11% lower than for the SNP316 CG genotype and 17% lower than for the SNP316 GG genotype. There were very few steers with the SNP530 AA genotype and, contrary to previous studies, meat from steers with the SNP530 GG genotype showed an 11.5% higher shear force than that from steers with the SNP530 GA genotype. Final body weight, carcass weight and rib eye area were not affected by any of the markers. These results support the concept that CAPN1 variants are associated with tenderness across a wide range of beef production systems.

Detection of Tenderness, Post-Rigor Age and Water Status Changes in Sheep Meat Using near Infrared Spectroscopy

The tenderness (objective measure is shear force) of sheep meat ( longissimus thoracis et lumborum) during post-rigor ageing at 15°C can be predicted using near infrared (NIR) analysis ( r2 = 0.85). Measurements ( n = 260 from 65 lambs) were made at 0, 8, 24 and 72 h post-rigor using an interactance system operating over the spectral range from 400–1700 nm. There was no predictive power in the NIR models to segregate tenderness measurements made at any one particular post-rigor time. NIR measurements could segregate the post-rigor ages with good accuracy ( r2 = 0.91). The OH combination band at 840 nm is the dominant feature of the predictive models and suggests that the underlying chemistry is related to the post-rigor changes in the water status of the meat. Observations on another similar data set ( n = 48 from 12 lambs), involving NIR and water content measurements, confirmed there are significant water changes in meat during aging. We speculate that the NIR models may be sensitive to the accumulation of free water arising from the degradation of cytoskeletal proteins during ageing, releasing the water normally tightly bound up in the tertiary protein structures.

Effects of feeding browses on growth and meat quality of Korean Black Goats

Effects of feeding browses on growth and meat quality of Korean Black Goats were investigated. Twenty-eight bucks were divided in equal numbers into four treatment groups and fed fibrous diets of oak browse, pine browse, fermented pine browse or rice straw each with concentrate supplement. Metabolic profile, growth rate, feed intake, carcass yield, meat quality and serum were investigated. Average daily gains of bucks were 45.3 g for oak browse, 36.4 g for rice straw, 28.1 g for pine browse and 30.0 g for fermented pine browse. Daily forage intake per goat was 197 g DM for oak browse, which was higher than those for the other diets. Bucks fed fermented pine browse ate only 74 g forage per day. Body metabolism was normal with all sources of browses from the results of serological inspection. Dressing percentage was 45.1–46.2%. Meat percentage was 55.2–55.9% and fat percentage was 7.31% for oak browse which was lower than those for pine browse and fermented pine browse. Shear force of goat meat was 4.11–5.11 kg/cm 2 for browses and 6.30 kg/cm 2 for rice straw. Cooking loss was 29.6% for pine browse which was lower than the others. Juiciness, tenderness and flavor of the goat meat were the best for the fermented pine browse followed by other browses and rice straw.

The Influence of Production Systems on Meat Quality, with Emphasis on Pork

Technological, nutritional, and sensory meat quality may be influenced by multiple interacting factors before and after slaughter. Reviewing the literature, it can be seen that alterations aimed at creating more sustainable production systems for pig meat generally have either no effect or a lowering effect on the ultimate pH value of the meat. Some studies indicate reduced water-holding capacity in sustainably produced pork. Outdoor production may be expected to increase further the shear force of the meat compared to conventional systems. The color may be affected in different ways, leading to either darker, more pigmented meat or paler, structurally effected meat. The more unsaturated profile of the lipids in meat produced in a system that includes feeds containing polyunsaturated fatty acids is favorable with respect to the nutritional quality of the meat. To conclude, the combinatory effects of, for example, feeding, production systems, genotype, sex, and preslaughter treatments, have to be addressed.

Evaluation of broiler performance when fed insect-protected, control, or commercial varieties of dehulled soybean meal

We evaluated the nutritional value of broiler diets containing approximately 35% soybean meal from insect-protected soybean containing CrylAc protein, or from a similar nontransgenic control, or from 7 reference commercial soybean varieties. The feeding trial lasted 41 d, and each treatment consisted of 10 replicates of 1-d-old Ross 508 broilers (5 pens males and 5 pens females). Each pen contained 12 birds, and at d 13, birds were randomly removed until 9 birds remained. Body weight and feed intake were measured on pen basis at 41 d. At d 42, 4 broilers per pen were slaughtered. The carcasses were dissected, and cut-up yields were determined. Dry matter, protein, and fat contents of breast meat as well as shear force of breast meat were determined. The data were analyzed by ANOVA. The BW and feed conversion ratio at d 41 averaged 2,435 g and 1.52, respectively. There were no significant treatment x sex interactions. Data for final BW, feed conversion, carcass yield, and breast meat data were not different (P < 0.05) between broilers fed insect-protected and those fed commercial soybean meal varieties. Thus, insect-protected soybean meal was nutritionally equivalent to nongenetically modified soybean varieties when fed to broilers.

한국 전통 양념으로 제조한 돼지고기의 숙성중 물리화학적 변화

한국 전통 양념 (T1, 된장소스; T2, 마늘소스; T3, 고추장소스)을 이용하여 0<TEX>${\pm}$</TEX> <TEX>$1^{\circ}C$</TEX> 에서 30일 동안 숙성 중 돼지고기의 물리화학적 변화를 측정한 결과는 다음과 같다. 숙성기간동안 양념의 염도와 당도는 유의적으로 감소한 반면, 육에서는 증가하였고(P<0.05), pH는 숙성기간 동안 양념과 육에서 증가하는 경향을 나타내었다. 보수력과 전단력은 모든 처리구에서 숙성 20일에 유의적으로 높게 나타났으나 이후 다시 감소하였고, 육색은 T3의 <TEX>$L^*과 b^* 값은 낮고, a^*$</TEX> 값은 숙성기간 동안 다른 처리구에 비해서 다소 높게 나타났다. VBN은 모든 처리구에서 숙성 20일에 유의적으로 증가하였으며 T3가 다른 처리구보다 높게 나타났다. TBARS는 저장 10일에 급격히 증가하였다가 저장 20일에 감소한 후 다시 증가하였고 T3가 가장 높은 값을 나타내었다. 총균과 유산균은 저장 10에 증가하다 저장 20일에 감소하였으며 그 후 증가하는 경향을 나타내었고 대장균은 저장기간에 따라 감소하였으며 저장 30일에는 모든 처리구에서 나타나지 않았다. 전체적인 기호도는 모든 처리구에서 숙성 초기보다 20일 이후 높게 나타났으며 30일에도 같은 경향을 나타내었다. This study was conducted to investigate physico-chemical changes of pork prepared by Korean traditional 3 types seasoning such as soybean sauce(Tl); garlic sauce(T2); red pepper sauce(T3). The seasoned samples were aged at 0 <TEX>${\pm}$</TEX> <TEX>$1^{\circ}C$</TEX> for 30 days. The results obtained were as follows; Salinity(%) and saccharinity(%) of sauce were significantly decreased(P<0.05) among the all treatments during aging periods, whereas fermented meats were significantly increased(P<0.05). pH of sauce and fermented meat were tended to increased as aging period. Water-Holding Capacity(WHC) and shear force of fermented meat increased(P<0.05) among the all treatments at 20 days of storage, and decreased after that period. In color, <TEX>$L^* and b^* value of T3 were lower, while a^*$</TEX> value was higher than other treatments during aging period. Volatile Basic Nitrogen(YBN) value of all treatments were increased(P<0.05) after 20 days of storage. YBN value of T3 was significantly higher(P<0.05) compared with other treatments. Thiobarbituric Acid Reactive Substances(TBARS) was rapidly increased until 10 days of storage and somewhat decreased up to 20 days after 10 days in all treatments, it was re-increased after 20th days. T3 showed the highest TBARS among the all treatment groups. Total bacterial and Lactobacilli spp. were significantly increased(P<0.05) in all treatments at 10 days of storage and decreased after that period, however it tended to increased at 30 days of storage. In sensory evaluation, overall acceptability in all treatments were increased after 20 days of storage compared to initial storage and it score was similar thereafter.

Desempenho, fibras musculares e carne de bovinos jovens de três grupos genéticos

O objetivo deste trabalho foi avaliar as características de desempenho, carcaça, qualidade de carne e das fibras musculares esqueléticas de bovinos jovens de três grupos genéticos, Angus x Nelore, Canchim x Nelore e Simental x Nelore. Noventa bovinos inteiros mestiços jovens, com idade média de oito meses, sendo 30 de cada grupo genético, foram distribuídos em delineamento experimental inteiramente casualizado, com três tratamentos (grupos genéticos) e seis repetições. Nas análises das fibras musculares, foram utilizados seis animais por tratamento e na avaliação de desempenho e características de carcaça, foram utilizados todos os animais. Em relação a ganho de peso diário, rendimentos de carcaça e cortes cárneos, área do músculo longissimus dorsi e proteínas e lipídeos totais na carne, não houve diferença entre os grupos genéticos, porém os mestiços Angus apresentaram maior espessura de gordura subcutânea. A maciez da carne não variou entre os grupos genéticos e entre os períodos de 7 e 14 dias de maturação. A semelhança da maciez da carne de 7 e 14 dias permite que o tempo de maturação das carnes seja reduzido, quando se utiliza animais jovens.

Effect of ageing time on consumer-perceived quality of Italian Simmental beefRiassuntoeffetto Della Durata Della Frollatura Sulla Percezione Di QualitÀ Del Consumatore Nei Confronti Della Carne Di Pezzata Rossa Italiana

The aim of the experiment was to provide an objective indication on the optimal ageing time of meat from Italian Simmental (IS) young bulls, the most important commercial category of the breed. The research was carried out on 10 young bulls slaughtered at the average weight of 688 kg (SE: 7.3 kg). The right side of each carcass was stored for 7 days and the left one for further 7 days, at normal refrigeration temperatures. At the end of the ageing period, the sides were sampled at the loin for meat pH, color, cooking loss and shear force measurement. A central location, affective test involving 74 consumers was carried out to measure the degree of liking for grilled beef aged 7 or 14 days.The pH and color parameters were not significantly affected by the duration of post-mortem storage, while cooking loss increased (31.4 vs 32.6 %; P<0.05) and shear force values diminished (56.7 vs 46.8 N; P< 0.01) when ageing time increased from 7 to 14 days. The degree of liking by the untrained respondents for the two types of cooked meat was different, considering that consumers gave the highest hedonistic scores to beef aged 14 days. Tenderness was the sensory attribute that allowed the best discrimination between beef stored for periods of different length. In fact, while the difference between 14-day-aged and 7-day-aged beef for flavour ratings (7.0 vs 6.9) did not reach the threshold of significance, the former meat was perceived as significantly finer than the latter regarding tenderness (6.5 vs 5.6; P= 0.01) and marginally preferred in overall terms (6.9 vs 6.5; P= 0.07). The classification test, carried out at the end of the quantitative test by asking consumers to select from a list the most appropriate attributes describing the stimuli associated with meat consumption, confirmed the effectiveness of texture attributes in ranking different-aged beef acceptability. In fact, the number of ticks reported for chewiness and juiciness descriptors were different for the two types of meat: the 14-day-aged beef was perceived as easier to chew (57 vs 34 ticks) and juicier (42 vs 24) than the shortest-aged beef.Ageing for 14 days should be recommended as a process control point for the beef industry to improve consumer acceptance of IS young bull beef.

Efeito da linhagem e do nível de lisina da dieta sobre a qualidade da carne do peito de frangos de corte

O experimento foi conduzido com o objetivo de avaliar o efeito da linhagem e do nível de lisina da dieta sobre o rendimento e a qualidade da carne de peito de frangos de corte. Foram utilizados 2250 pintos não sexados, de três linhagens comerciais, identificadas como A, B e C, distribuídos em delineamento inteiramente casualizado em esquema fatorial 3x3 (linhagens e níveis de lisina), com cinco repetições de 50 aves. As aves receberam ração à vontade, à base de milho e farelo de soja, suplementadas com 1,18; 1,24 e 1,30% de lisina nas rações pré-iniciais (1 a 7 dias); 1,10; 1,16 e 1,22% nas rações iniciais (7 a 21 dias); 1,0; 1,06 e 1,12% nas rações de crescimento (21 a 35 dias) e 0,85; 0,91 e 0,97% nas rações de terminação (35 a 42 dias). Foram avaliadas as características de rendimento de peito e carne de peito e as medidas de espessura, largura, comprimento, pH, perda de peso por cozimento e força de cisalhamento da carne de peito. Para o rendimento de peito não foram observadas diferenças significativas, enquanto para rendimento de carne de peito houve efeito significativo da linhagem, em que a linhagem A apresentou o maior rendimento e a linhagem B, o menor. Para as medidas físicas da carne do peito, foram encontradas diferenças significativas entre as linhagens para comprimento de peito, com a linhagem C apresentando o maior resultado. O pH da carne diferiu significativamente para linhagens e níveis de lisina. As linhagens tiveram efeito sobre o rendimento, comprimento e pH da carne de peito, em que a linhagem A apresentou maiores valores para rendimento e pH e a linhagem C para comprimento.

The relationship between postmortem urinary catecholamines, meat ultimate pH, and shear force in bulls and cows

We investigated the relationship between stress responsiveness and meat quality in cattle. The cattle were 16–19-month-old Mixed ( n=37, 303 kg) or Non-mixed ( n=23, 279 kg) Friesian bulls and Friesian cull cows (1.5–7 years) that were classified Unfinished ( n=133, 195 kg) or Finished for 3 months ( n=34, 252 kg). A portion of m. longissimus lumborum (LL) muscle was obtained from consecutive animals for a single days slaughter of 227 cattle processed through a hot boning plant. Catecholamines were obtained from bladder urine. Ultimate pH, lactate, glycogen, glycolytic potential and representative sarcomere lengths were determined from 20-h muscle samples. Shear force measurements were from meat aged at 15 °C for 20 and 90 h. Urinary noradrenaline was similar between Mixed (14.86 ng/μmol creatinine) and Non-mixed bulls (14.07 ng/μmol creatinine) and Finished cows (15.24 ng/μmol creatinine) and elevated in the Unfinished cows (22.28 ng/μmol creatinine). Urinary adrenaline was higher in Mixed bulls (9.5 ng/μmol creatinine) than Non-mixed bulls (5.7 ng/μmol creatinine) and higher in both Unfinished cows (16.67 ng/μmol creatinine) and Finished cows (14.19 ng/μmol creatinine). For bulls that are growing well on-farm, with a only short period of fasting prior to slaughter, pH u is a good predictor of meat tenderness. In this situation, stressors that lower muscle glycogen pre-slaughter can have a significant effect on meat shear force, and individual animals with elevated urinary adrenaline were the most susceptible. However, in the case of cows, adrenaline responses are not necessarily associated with glycogen depletion and pH u is less affected than for bulls. Furthermore, the ability of meat to tenderise fully, related to reduced proteolytic turnover, is reduced in nutritionally compromised animals such as the Unfinished cows.

지엽류 급여가 흑염소의 발육 및 육질에 미치는 영향

지엽류 급여가 흑염소의 발육 및 육질에 미치는 영향을 구명하기 위하여 체중 13kg 내외의 4개월령 흑염소 수컷 28두를 공시하여 처리구별로 각각 7두씩 배치하여 농후사료와 함께 지엽류를 급여한 결과는 다음과 같다. 일당증체량은 참나무지엽구가 45.3g으로 다소 높은 경향이었고 소나무지엽구와 발효지엽구는 비슷하였다. 일일 조사료 섭취량은 참나무지엽구가 건물 197g이었고 발효지엽구가 74g이었다. 증체 g당 사료요구율은 참나무지엽구가 11.0g이었고 소나무지엽구는 15.1g이었다. 지엽류를 급여한 흑염소의 혈청 화학치는 영양장애나 체내대사에 이상이 없는 것으로 나타났다. 도체율은 45.1~46.2%이었고 정육율은 55.2~55.9%로 처리구간에 비슷하였으며 고기의 일반조성분인 조단백질과 조회분은 처리구간에 비슷하였고 조지방은 소나무지엽구와 발효지엽구가 볏짚구보다 낮았으나(p〈.05) 참나무지엽구와는 비슷하였다. 육질의 물리적 특성인 전단력, 가열감량은 소나무지엽구와 발효지엽구가 볏짚구보다 낮았으며(p〈.05) 지엽류 간에는 비슷하였다. 다즙성, 연도 그리고 향미는 소나무지엽구가 볏짚구보다 우수하였으며(p〈.05)지엽류 급여구간에는 비슷하였다. Effects of feeding browses on growth and meat quality of Korean native goats were investigated. Twenty eight heads of male goats were divided into four treatment groups fed diets containing oak browse, pine browse, fermented pine browse, and rice straw. Growth rate, feed intake, carcass and meat quality and blood and serum criteria were investigated. The highest average daily gain of goats was 45.3g from oak browse, and goats on pine browse gained similar to those on fermented pine browse. Daily forage intake was 197g DM for oak browse and 74g DM for fermented pine browse. Feed efficiency(g feed/g gain) of oak browse was 11.0g and that of pine browse was 15.1g. From the results of serological inspection, metabolism in body was normal with all the browses tested. Dressing percentage was 45.1~46.2% and meat percentage was 55.2~55.9% without significant differences between diets. Fat percentage of goat carcasses fed rice straw was higher than those fed pine browse or fermented pine browse which was, however, not significantly different from those on oak browse. Shear force and coking loss of goat meat on pine browse or fermented pine browse was less than those on rice straw(p〈0.05) without significant differences between other browses. Juiciness, tenderness, and flavor of the goat meat were the better(p<0.05) from the pine browse diet than from rice straw.

Perimysial collagen crosslinking and meat tenderness in Belgian Blue double-muscled cattle

The relationship between intramuscular collagen and five collagen crosslink concentrations, and the tenderness of meat from Belgian Blue normal, heterozygous double-muscled (DM) and homozygous DM cattle was investigated using M. semitendinosus (St) and M. gluteobiceps (Gb). The histidinohydroxymerodesmosine (HHMD) concentration (per mol collagen) in St was less in DM animals than normal animals. Concentrations (per gram of wet meat) of HHMD and Erlich chromogen (EC) in Gb, and HHMD, EC, dihydroxylysinorleucine (DHLNL) and hydroxylysinorleucine (HLNL) in St were also lower in DM animals than normal animals. Shear force of raw meat was significantly greater in normal animals than DM for both muscles; cooked meat shear force was greater in the normal animals for the Gb muscles only, showing a good correlation with sarcomere length. Most correlations between shear force and collagen or crosslink concentrations were not significant and those that were highly significant were generally weak.

Citrus pulp and wheat straw silage as an ingredient in lamb diets: effects on growth and carcass and meat quality

Twenty “Merinizzata Italiana” lambs were introduced to two experimental diets. Ten animals (five males and five females, control group) received the traditional diet that is supplied by farmers in southern Italy, which comprised of oat hay ad libitum and commercial concentrate. The second group (the same number of lambs, silage group) received citrus pulp and wheat straw silage ad libitum and 70% of the commercial concentrate supplied to the control group. The animals were slaughtered after 80 days of feeding and carcass and some meat quality parameters were measured. No differences were observed for live weight between treatments, and carcass weights were similar for the two diets, but with obvious differences between sexes. Animals on silage produced carcasses with a better muscular conformation and with a lower fatness score ( P<0.05). Subcutaneous fat colour was influenced by sex, being lighter in the female carcasses ( P<0.05). Dissection of different anatomical parts showed a higher percentage of lean and a lower proportion of fat in silage samples compared to control ones. Ultimate pH was highly affected by sex being higher in the samples from male lambs ( P<0.01), but was unaffected by diet treatment. Diet tended to affect meat shear force value which was lower in the silage samples, although, samples from all the animals were extremely tender. Meat from silage samples had a higher water content ( P<0.05). Overall, in our experimental conditions, the use of citrus pulp silage seemed to be economically convenient for producing animals with substantially unmodified carcass and meat quality characteristics.

Influence of preslaughter stunning on turkey breast muscle quality

Pectoralis muscle quality was evaluated from 18-wk-old tom turkeys after electrical stun, carbon dioxide stun, or no stun methods were applied. Color was measured on raw muscle and cooked meat using a colorimeter. Muscle pH was measured 15 min post-mortem (initial), 24 h post-mortem (final), and after cooking. The right Pectoralis muscle of each carcass was excised for m-calpain analysis within 4 min post-mortem. After 24 h of storage at 4 C, the left Pectoralis muscle was excised to determine cook loss and shear force measurements. No significant difference was found in initial muscle pH (15 min) from turkeys receiving electrical or carbon dioxide stunning, 6.36+/-0.15 and 6.20+/-0.14, respectively. However, initial muscle pH for birds that were not stunned (5.99+/-0.08) was lower (P < 0.05) than the muscle pH of birds stunned using either of the two stunning methods. Stunning method had no effect on the final muscle pH, raw muscle color, cooked meat pH, cooked meat color, cook loss, or shear force. Cook loss was found to positively correlate with initial muscle lightness (r = 0.53), and cooked meat lightness (r = 0.48), but to negatively correlate with cooked meat yellowness (r = -0.48) and shear strength (r = -0.43). m-Calpain activity declined with the stunning methods in the following order: electrical > carbon dioxide > no stun. In addition, m-calpain activity was found to correlate with initial muscle pH (r = 0.95) and with cooked meat shear force (r = -0.43). The results of this study show that electrical stunning, carbon dioxide stunning, and no stunning methods provide comparable cooked turkey breast meat quality with no consistent differences after aging on the carcass for 24 h.

Meat tenderness and the calpain proteolytic system in longissimus muscle of young bulls and steers1

The objectives of this study were to examine the effects of castration on the calpain proteinase system (mu-calpain, m-calpain, and calpastatin) activities and meat tenderness. Six each, MARC III bulls and steers were slaughtered at approximately 12 mo of age. Longissimus muscle samples were obtained for determining myofibril fragmentation index, Warner-Bratzler shear force, and sensory panel evaluation at 1, 7, and 14 d postmortem, and mu- and m-calpain and calpastatin activities at 24 h postmortem. Bulls produced leaner carcasses with lower (P < .05) quality grades than did steers. Meat from bulls had higher (P < .05) shear force values than meat from steers; however, sensory panelists were unable (P > .05) to detect differences in tenderness or other sensory traits between bulls and steers. Activities of mu- and m-calpain were not affected (P > .05) by castration; however, calpastatin was higher (P < .05) in muscles from the bull carcasses. Lower (P < .05) myofibril fragmentation index values indicate that less proteolysis occurred in muscle from bulls than in muscle from steers during the first 7 d postmortem. Greater calpastatin 24-h activity may be associated with the increased shear force of meat from bulls.

Effects of ewe breed and management system on efficiency of lamb production: III. Meat characteristics

Effects of management system, ewe breed, sex, and legume grazing on cooking and sensory characteristics and shear force of lamb meat were estimated from data collected on animals produced in three management systems. System 1 lambs were born in late fall and fed to slaughter on a concentrate diet. System 2 lambs were born in January and February and grazed pure stands of alfalfa or ladino clover after weaning. System 3 lambs were born in March and April and remained with their dams on native bluegrass-white clover pasture throughout the grazing season. Lambs were progeny of either 1/2-Suffolk, 1/2-Rambouillet ewes or 1/2-Suffolk, 1/4-Finnsheep, 1/4-Rambouillet or Dorset ewes and were sired by Suffolk rams. Lambs were slaughtered at 50 (females) to 55 kg (males). One-half of the males in System 1 were left intact; all males in Systems 2 and 3 were castrated. Mean age at slaughter was 156, 204, and 234 d for lambs in Systems 1, 2, and 3, respectively. Cooked weight of loin chops averaged 68.5% of uncooked weight and did not differ among systems. Shear force was greatest for System 1 lambs and least for System 3 lambs in yr 1, but systems did not differ in shear performance in yr 2. System differences in tenderness favored System 3 lambs. Although mean flavor intensity was least for System 2 lambs, the frequency of high-intensity, potentially objectionable flavors was highest for these lambs and especially for those grazing alfalfa. In general, however, sensory characteristics did not differ greatly among production systems, and correlation analysis revealed little potential to use carcass traits to predict meat characteristics.

Twinning Agreement with Adriant

The effect of aging time in vacuum on tenderness, and lipid and color stability of modified-atmosphere packaged (MAP) beef during display was evaluated in eight Friesian mature cows. Longissimus thoracis et lumborum (LTL) sections were vacuum packaged and aged for 0, 3, 6, 8, 14 and 21 days. After each aging time, the LTL sections were cut into steaks and packaged in high oxygen atmosphere (80% O2: 20% CO2). Meat shear force, and color and lipid stability were evaluated at 0, 3, 6, and 9 days of simulated retail display. Aging for 6 or 8 days improved beef tenderness with color stability, instrumental discoloration (R630–R580) and visual color evaluation in MAP similar to those of short-time aged (3 d) or un-aged (0 d) beef. Longer aging times (14 and 21 d) resulted in tenderness values similar to those obtained with meat aged for 8 days but affected negatively color and lipid stability and, consequently, reduced the shelf life of beef in MAP.