Carcass Grade Research Articles

답리작 재배 청보리 사일리지 급여가 거세 한우의 증체, 사료요구량 및 육질에 미치는 영향

본 연구는 답리작에서 보리를 재배하여 사일리지를 조제하고 거세 한우에게 청보리 사일리지를 급여하여 성장, 사료이용성, 도체특성 및 육질개선 효과를 구명하고자 전북 정읍 농가에서 4개월령 거세 한우 육성우 21두를 공시하여 27개령까지 사육하였다. 대조구(일반볏짚구), 청보리 사일리지구, 생볏짚 사일리지+청보리 사일리지구 등 3처리를 두었으며, 배합사료는 육성기는 체중의 1.5%, 비육전기는 1.8%, 비육후기는 자유 채식하도록 하였고, 조사료는 사육기간 자유채식을 원칙으로 하였다. 청보리 사일리지의 평균 생산량은 ha당 사일리지 17,135 kg, 건물 6,011 kg 이었으며, 사일리지의 품질등급은 청보리에서 2~3등급, 생볏짚은 4등급이었다. 청보리 사일리지 급여로 거세 한우증체와 배합사료 절감효과가 뚜렷하였는데, 육성기에는 일당증체 65% 증가, kg 증체당 배합사료 35% 절감, 비육전기는 일당증체 7% 증가, kg 증체당 배합사료 19% 절감, 그리고 전기간으로는 일당증체 8% 증가, kg 증체당 배합사료 18% 절감효과가 있었다. 또 청보리 사일리지구에서 육질 1등급 이상 출현율은 62.5%로 대조구(37.5%)에 비해 높았으며, 근내지방도도 4.38로 대조구(2.75)에 비해 높았고, 고기의 보수력, 가열감량, 다즙성, 연도, 향미 등도 우수하였다(p<0.05). 답리작 재배 청보리는 양질 사료작물로 거세 한우의 증체와 배합사료 절감, 육질개선에 효과적이었으며, 육성기와 비육전기 위주 급여가 바람직하였고, 답리작을 이용한 월동 사료작물 재배확대가 기대되었다. This study was carried out to investigate the effect of feeding whole crop barley silage (WBS) on the growth performance, gain, feed requirement, carcass grade and beef quality of Hanwoo steers in 1999 to 2001. Twenty one steers were allocated, and divided into three treatment groups which fed rice straw only (control), WBS only, and fresh rice straw silage plus WBS during overall period ad libitum. Concentrates were fed at 1.5% level of live-body weight during growing stages, 4~12 months of age, at 1.8% level of live-body weight during early fattening stages, 13~18 months of age, and ad libitum after late fattening stages, 19~27months of age. The production yields of WBS were 17,135 kg as a silage, and 6,011 kg as a dry matter per ha, and the quality of WBS was 2~3 grade, while that of rice straw silage was 4grade. The daily gain with feeding of WBS (0.70 kg) during experimental period was higher than that of control group (0.65 kg), and the concentrate requirement (7.31 kg) per kg gain in WBS was lower than that of control (8.95 kg). The effects of gain and feed efficiency were very distinct during growing stage. i.e., the daily gain of WBS (0.84 kg) was increased by 65% compared to control (0.51 kg), and the concentrate requirement (4.16 kg) per kg gain in feeding of WBS was decreased by 35%, compared to control (6.39 kg). Meat quality with WBS was higher than that of control. Frequency rate of 1 and/or <TEX>$1^+$</TEX> grade, and marbling score of feeding of WBS were 62.5% and 4.38, while those of control were 37.5% and 2.75, respectively. The results of the sensory evaluation showed that Hanwoo beef fed with WBS were better than that of control. In conclusion, feeding of WBS was desirable to improve daily gain, reduction of concentrates, feed efficiency and meat quality of Hanwoo steers.

Association of liver abnormalities with carcass grading performance and value

The association of liver abnormalities with carcass grading performance, value, and dressed yield was evaluated on data from 76,191 carcasses housed in 2 databases. Liver abnormalities were assigned as follows: normal = edible liver; A- = 1 to 2 small abscesses or inactive scars; A = 1 to 2 large abscesses or multiple small abscesses; A+ = multiple large abscesses; A+AD = liver adhered to gastrointestinal tract or diaphragm or both; A+OP = open liver abscess; cirrhosis; distoma; and telangiectasis. Overall liver abnormality rates among both databases were A- = 5.0%, A = 2.6%, A+ = 2.0%, A+AD = 2.7%, A+OP = 1.4%, cirrhosis = 0.1%, distoma = 5.4%, and telangiectasis = 0.3%, with 80.5% of livers being normal. In database 1 (n = 3,936), BW was 33.3 kg less (P < 0.01) for carcasses with cirrhotic livers compared with carcasses with normal livers. Dressed yields for carcasses with A-, A+, A+AD, A+OP, and cirrhosis liver abnormalities were 0.28 to 0.89 percentage points less (P < 0.05) than carcasses with normal livers. In database 2 (n = 72,255), carcasses with A-, A+, A+AD, A+OP, cirrhosis, distoma, and telangiectasis liver abnormalities had reduced (P < 0.05) HCW and reduced (P < 0.05) LM area as compared with carcasses with a normal liver. Less (P < 0.05) 12th-rib subcutaneous fat was observed for carcasses with A-, A, A+, A+AD, A+OP, cirrhosis, and distoma abnormalities compared with carcasses with normal livers. Estimated KPH was less (P < 0.05) for carcasses with A-, A+, A+AD, A+OP, cirrhosis, and distoma abnormalities. Calculated yield grade was less (P < 0.05) for carcasses with A+AD, A+OP, cirrhosis, and distoma abnormalities compared with carcasses with normal livers. Marbling score of carcasses that had livers with A+AD or A+OP abscess scores or distoma was less (P < 0.05) than that of carcasses with normal livers. In database 2, market price per 45.35 kg did not differ (P = 0.32) among liver classification. Gross carcass value analyses indicated carcasses with A-, A, A+, A+AD, A+OP, cirrhosis, and distoma liver abnormalities were less valuable (P < 0.05) than carcasses with normal livers. These data delineate the association of liver abnormalities present at harvest with subsequent changes in carcass characteristics and ultimately lost carcass value.

제주재래돼지의 성별 및 도체등급에 따른 도체특성 분석

본 연구는 도체등급을 판정받은 제주재래돼지 168두(거세돈 116두와 암퇘지 52두)를 공시돈으로 재래돼지의 성별, 도체 육질 등급별 및 육량등급별 도체특성을 조사하여 고급돈육 생산에 필요한 기초자료를 얻고자 실시하였다. 재래돼지의 도체특성의 평균치는 도체중이 72.94 kg, 도체율 72.46%, 등지방두께 20.98 mm, Hunter L* 값 38.14, a* 값 4.68, b* 값 6.04, pH 5.61, 육색도 3.61, 근내지방도 3.36, 육질등급 1.83, 그리고 육량등급 2.08로 조사되었다. 성별 도체특성에서 도체중은 암퇘지가 75.69 kg으로 거세돈 71.71 kg 보다 유의하게 무거웠으나(p<0.05), 도체율, 등지방두께, 그리고 육색도에서는 성별 간에 모두 유의한 차이가 없었다. pH는 암퇘지와 거세돈에서 각각 5.58과 5.62로 거세돈이 유의하게 높게 나타났다(p<0.05). 도체육질등급에서는 거세돈과 암퇘지의 평균등급은 1.95와 1.58로 거세돈이 유의하게 높은 등급을 보였다(p<0.05). 그리고 육량등급에서도 성별 간에 유의한 차이를 보였는데(p<0.05), 거세돈 1.90 등급보다 암퇘지 2.50 등급으로 암퇘지가 높게 나타났다. 도체 육질등급별 도체특성에서는 도체중은 도체등급이 높을수록 유의하게 무거운 것으로 나타났으며(p<0.05), 도체율에서도 도체육질등급이 높을수록(1과 2등급) 유의하게 높은 것으로 나타났다(p<0.05). 등 지방 두께는 등급 간에 유의한 차이를 보였는데(p<0.05), 등급이 높을수록 등지방 두께가 높았다. 육색도에서는 등급 간에 Hunter L* 값, a* 값, b* 값 모두 유의한 차이를 보이지 않았다. 근내지방도는 1등급은 4.06점과 3등급은 2.64점으로 등급이 높을수록(양호) 유의하게(p<0.05) 높은 점수를 보였다. 도체 육량등급별 도체특성에서 도체중과 도체율은 등급 간에 모두 유의한 차이를 보였는데(p<0.05), 등급이 높을수록(A 등급) 체중이 무겁고 도체율이 높은 것으로 나타났다. 등지방두께는 A 등급은 22.83 mm로 유의하게 높은(p<0.05) 반면에, D 등급은 18.63 mm로 등급이 낮을수록 등 지방두께도 얇았다. 육색도는 Hunter L* 값, a* 값, b* 값 모두 등급 간에 유의한 차이가 발견되지 않았으나, pH 값은 A 등급에서 5.53으로 하위등급보다 유의하게 높은 것으로 나타났다(p<0.05). 육색도판에 의한 육색도에서도 유의한 차이를 보였다(p<0.05). 근내지방도는 등급 간에 유의한 차이를 보였는데(p<0.05), 상위 A, B 등급에서는 4.00 이상으로 높았으나, 하위 C와 D 등급에서는 3.06 이하의 낮은 점수로 나타났다. 따라서 제주 재래종은 개량종보다 등지방두께는 양호하였으나, 육질과 관련된 특성을 더욱 더 심도있는 비교연구로 정확한 평가가 이루어져야 할 것으로 생각된다. The Jeju native pigs of 168 heads (116 barrows and 52 gilts) were examined to investigate the carcass characteristics related to gender, meat quality grades and yield grades. The averages of carcass characteristics for Jeju native pigs were 72.94 kg for carcass weight, 20.98 mm for backfat thickness, 38.14 for Hunter L*, 4.68 for a*, 6.04 for b*, 5.61 for pH, 3.61 for visual plate meat color, 3.36 for marbling scores, 1.83 for meat quality grades and 2.08 for yield grades, respectively. The carcass weight of gilts was significantly higher than that of barrows (p<0.05). There were no significant differences between barrows and gilts in carcass percent, backfat thickness, and meat color. The pH of barrows was significantly higher than that of gilts (p<0.05). The differences between gender groups were significantly noticed in carcass quality grades, and yield grades (p<0.05). The carcass weight, carcass percent, backfat thickness, and marbling scores for pigs with high grades(1 and 2 grades) were significantly higher than those for pigs with low grades (p<0.05). However, there was no significant difference among 4 carcass grades. The carcass weight, carcass percent, backfat thickness, pH, and meat color for carcass with high yield grades were significantly higher than those for carcass with low grades (p<0.05). The meat colors for Hunter L*, a* and b* were not significantly shown in carcass yield grades.

EFFECT OF TRANSPORT DURATION AND GENDER ON RABBIT CARCASS AND MEAT QUALITY

In order to evaluate the effect of transport duration and gender on carcass and meat quality, 204 rabbits were reared in individual cages from 35 d of age until slaughter at 77 d (average live weight at shipping: 2662±189 g). Before slaughter, four groups of rabbits were formed and transported for 2, 4, 6, or 8 hours from the breeding unit to the slaughterhouse. Increasing the duration of transport increased transport losses (2.44% to 4.59%; P&lt;0.001), decreased dressing percentage (59.5% to 58.9%; P&lt;0.01) and increased the redness of the longissimus dorsi muscle (CIE a* 2.38 to 2.73; P&lt;0.05). Commercial carcass grading for colour, conformation and fatness were not affected by transport duration. The effect of gender was appreciable at slaughter: final live weight and transport losses were higher in females than males. Dressing percentage was lower in females (59.1 vs 59.8%; P&lt;0.01) due to the greater gut content. Carcasses of females showed a higher proportion of longissimus muscle (P&lt;0.01). The meat of females was darker (CIE L* of biceps femoris muscle: 54.9 vs 55.9; P&lt;0.01) and less coloured (Chroma index of longissimus lumborum muscle: 3.52 vs 3.87; P&lt;0.05) than males.

Effects of Dietary Energy Level on Growth Efficiency and Carcass Quality Traits of Finishing Pigs

ABSTRACT A total of 96 non-lean-type (Yorkshire ×Landrace) × Duroc gilts and barrows weighing approximately 80 kg were randomly allocated to 24 pens under a 2 (sex) × 3 [diet; 3.4, 3.2, and 3.0 Mcal DE/kg {‘high’-, ‘medium’-, and ‘low’-energy diets (HE, ME, and LE), respectively}] factorial arrangement of treatments. All animals were slaughtered approximately at 115 kg, after which carcass quality traits and grades and physicochemical and sensory characteristics of the loin related to meat quality were analyzed. The ADG and gain:feed were not affected by the sex or dietary treatment, whereas ADFI was greater in the ME vs HE group. Backfat thickness was greater in barrows vs gilts and also in ME and HE vs LE only in barrows. Enumerated carcass marbling and quality grade, which were highly correlated (r=0.56; P<0.01), were greater in barrows vs gilts. Physicochemical characteristics including the color, pH, drip loss and contents of moisture, protein, and fat of fresh loin, as well as sensory characteristics of fresh and cooked loin, were not affected by the sex or dietary treatment, except for shear force for cooked loin which was greater (P<0.05) in LE and ME vs HE. In conclusion, it is thought that ME is comparable to HE in terms of the effect on growth and carcass quality of finishing pigs, but that the relative effect of LE vs ME needs to be further studied. (

Genetic Relationship between Carcass Traits and Carcass Price of Korean Cattle

The objectives of this study were to estimate genetic parameters for the carcass price and carcass traits contributing to carcass grading and to investigate the influence of each carcass trait on the carcass price using multiple regression and path analyses. Data for carcass traits and carcass prices were collected from March 2003 to January 2009 on steers of Korean cattle raised at private farms. The analytical mixed animal model, including slaughter house-year-month combination, linear and quadratic slaughter age as fixed effects and random animal and residual effects, was used to estimate genetic parameters. The effects of carcass traits on the carcass price were evaluated by applying multiple regression analyses. Heritability estimates of carcass traits were 0.20±0.08 for carcass weight (CWT), 0.33±0.10 for back fat thickness (BFT), 0.07±0.05 for eye-muscle area (EMA) and 0.25±0.10 for marbling score (MS), and those of carcass prices were 0.21±0.10 for auction price per 1 kg of carcass weight (AP) and 0.13±0.07 for total price (CP). Genetic correlation coefficients of AP with CWT and MS were -0.35±0.29 and 0.99±0.04, respectively, and those of CP with CWT and MS were 0.59±0.22 and 0.39±0.29 respectively. If an appropriate adjustment for temporal economic value is available, the moderate heritability estimates of AP and CP might suggest their potential use as the breeding objectives for improving the gross incomes of beef cattle farms. The large genetic correlation estimates of carcass price variables with CWT and MS implied that simultaneous selection for both CWT and MS would be also useful in enhancing income.

Meat standards and grading

This paper addresses the principles relating to meat standards and grading of beef and advances the concept that potential exists to achieve significant desirable change from adopting more consumer focused systems within accurate value-based payment frameworks. The paper uses the definitions that classification is a set of descriptive terms describing features of the carcass that are useful to those involved in the trading of carcasses, whereas grading is the placing of different values on carcasses for pricing purposes, depending on the market and requirements of traders. A third definition is consumer grading, which refers to grading systems that seek to define or predict consumer satisfaction with a cooked meal. The development of carcass classification and grading schemes evolved from a necessity to describe the carcass using standard terms to facilitate trading. The growth in world trade of meat and meat products and the transition from trading carcasses to marketing individual meal portions raises the need for an international language that can service contemporary needs. This has in part been addressed by the United Nations promoting standard languages on carcasses, cuts, trim levels and cutting lines. Currently no standards exist for describing consumer satisfaction. Recent Meat Standards Australia (MSA) research in Australia, Korea, Ireland, USA, Japan and South Africa showed that consumers across diverse cultures and nationalities have a remarkably similar view of beef eating quality, which could be used to underpin an international language on palatability. Consumer research on the willingness to pay for eating quality shows that consumers will pay higher prices for better eating quality grades and generally this was not affected by demographic or meat preference traits of the consumer. In Australia the MSA eating quality grading system has generated substantial premiums to retailers, wholesalers and to the producer. Future grading schemes which measure both carcass yield and eating quality have the potential to underpin the development and implementation of transparent value-based payment systems which will encourage improved production efficiency throughout the supply chain.

Assessment of meat quality properties and development of a palatability prediction model for Korean Hanwoo steer beef

Effects of the Korean carcass-grading system on carcass traits and meat quality parameters for the longissimus dorsi (LD) and semimembranosus (SM) muscles were investigated for Hanwoo steer beef. High quality grade beef cuts had significantly higher intramuscular fat content than those of low quality grade beef cuts. To establish a guaranteed system of eating quality for Hanwoo steer beef, a palatability prediction model was developed. The model development approach used canonical discriminant analysis and multivariate regression to assess effects of muscle type, cooking method, and aging treatment on Hanwoo beef quality grade. The palatability prediction model can provide Korean consumers with detailed information about expected eating quality for an individual cut, as well as provide critical information to the industry for maintaining high-quality beef production. The model is a significant advance in grading compared with the traditional carcass grading system, which applies a single quality grade to an entire carcass.

The prediction of carcass composition and tissue distribution in beef cattle using ultrasound scanning at the start and/or end of the finishing period

Ultrasound tissue depths, similar to those measured commercially as part of UK beef genetic evaluation schemes, were measured on 52 crossbred steers and 10 heifers at the start and end of the finishing period (average age 476 and 568 days, respectively). Animals were slaughtered at commercial target weights and carcass grades, and one carcass side fully dissected. Combining live weights and ultrasound tissue depths measured both before and after finishing provided the best predictions of carcass composition. Dissected fat weights and proportions in the carcass side, the forequarter and the hindquarter were predicted with high accuracy ( R 2 ∼ 0.8), muscle weights with moderate accuracy ( R 2 = 0.5–0.6), but muscle proportions were less accurately predicted ( R 2 = 0.23–0.49). Meat and Livestock Commission (EUROP) carcass conformation and fatness classes could also be predicted with moderate accuracy ( R 2 = 0.4 and 0.6, respectively). Fat and muscle weights in each quarter expressed as proportions of the total weight of that tissue in the carcass side were not predicted accurately ( R 2 < 0.4). Live weight and ultrasound data measured only at the start of finishing also gave good predictions of fat proportions in the carcass side and quarters ( R 2 = 0.64–0.67), and moderate predictions of fat and muscle weights and fatness class ( R 2 = 0.38–0.53), but low prediction accuracies for muscle proportions and conformation classes. In comparison, live weights and tissue depths measured only at the end of finishing explained 12 to 19% more of the variation in fat weights and fatness class, but predicted muscle weight, conformation class and fat proportions with similar accuracies and muscle proportions with similar or less accuracy. Including ultrasound fat depths, alongside muscle depth and live weight, in equations to predict muscle weights and proportions increased prediction accuracies to similar values as those estimated for fat traits, but increased confounding between predictions of different tissues. Derived prediction equations were validated on data from another 32 heifers and 48 steers, relating ultrasound-predicted weights to carcass tissue weights predicted from fore-rib sample joint dissections. Prediction accuracies ( R 2) of between 0.52 and 0.64 were achieved for fat and muscle weights and fat proportion in the carcass side, when the model included post-finishing measurements, but were lower (0.29–0.52) using only pre-finishing measurements. Predictions of muscle proportions and conformation classes were of poor accuracy, regardless of the model used.

Establishing an appropriate mode of comparison for measuring the performance of marbling score output from video image analysis beef carcass grading systems1,2

A beef carcass instrument grading system that improves accuracy and consistency of marbling score (MS) evaluation would have the potential to advance value-based marketing efforts and reduce disparity in quality grading among USDA graders, shifts, and plants. The objectives of this study were to use output data from the Video Image Analysis-Computer Vision System (VIA-CVS, Research Management Systems Inc., Fort Collins, CO) to develop an appropriate method by which performance of video image analysis MS output could be evaluated for accuracy, precision, and repeatability for purposes of seeking official USDA approval for using an instrument in commerce to augment assessment of quality grade, and to use the developed standards to gain approval for VIA-CVS to assist USDA personnel in assigning official beef carcass MS. An initial MS output algorithm was developed (phase I) for the VIA-CVS before 2 separate preliminary instrument evaluation trials (phases II and III) were conducted. During phases II and III, a 3-member panel of USDA expert graders independently assigned MS to 1,068 and 1,242 stationary carcasses, respectively. Mean expert MS was calculated for each carcass. Additionally, a separate 3-member USDA expert panel developed a consensus MS for each carcass in phase III. In phase II, VIA-CVS stationary triple-placement and triple-trigger instrument repeatability values (n = 262 and 260, respectively), measured as the percentage of total variance explained by carcasses, were 99.9 and 99.8%, respectively. In phases II and III, 95% of carcasses were assigned expert MS for which differences between individual expert MS, and for which the consensus MS in phase III only, was < or = 96 MS units. Two differing approaches to simple regression analysis, as well as a separate method-comparability analysis that accommodates error in both dependent and independent variables, were used to assess accuracy and precision of instrument MS predictions vs. mean expert MS. Method-comparability analysis was more appropriate in assessing the bias and precision of instrument MS predictions. Ether-extractable fat percentages (n = 257; phase II) differed among MS (P < 0.05) but were not suitable to predict or validate assigned MS. The performance and reproducibility of expert MS assignment in future evaluations was considered, and an official USDA performance standard was established, to which an instrument must conform to be approved for official on-line MS assessment. The VIA-CVS subsequently was approved to assign MS to carcasses on-line after completion of a 2006 USDA instrument approval trial conducted according to methods developed during completion of this study.

Effects of replacing barley grain with triticale-based dried distillers’ grains with solubles on nutrient digestibility, lamb growth performance and carcass traits

The objective of this research was to determine the effects of increasing proportions of triticale-based dried distillers’ grains with solubles (TDDGS) in the diet on nutrient digestibility, growth and carcass traits of lambs. The control diet contained 72.5% barley grain, 10.0% beet pulp, 9.0% sunflower hulls, 3.0% alfalfa meal and 5.5% mixed supplement, which contained molasses, calcium carbonate, minerals and vitamins. Treatment diets contained TDDGS in place of barley grain at 20, 40 or 60% of diet dry matter (DM). In a growth study, 60 weaned lambs stratified by live weight (26.6 ± 3.6 kg) were fed one of the four diets to slaughter weight. Additionally, a digestibility study using these diets in a replicated 4 × 4 Latin square design was conducted using 12 ram lambs. Increasing dietary allocation of TDDGS in the diet did not affect (P &gt; 0.12) DM intake, average daily gain or feed efficiency (feed:gain). At slaughter, cold carcass weight and grade rule scores responded quadratically (P = 0.04) to increasing TDDGS in the diets. Feeding TDDGS did not affect other carcass traits (P &gt; 0.22). Total saturated fatty acids and monounsaturated fatty acids in subcutaneous fat were unaffected by TDDGS, whereas polyunsaturated fatty acids increased linearly (P = 0.03). Concentration of t10, c12-conjugated linoleic acid (CLA) in carcass fat increased linearly (P = 0.02) with increasing TDDGS, but there was no effect (P ≥ 0.20) on concentrations of c9, t11-CLA or t11-18:1. In the digestibility study, DM intake increased linearly (P &lt; 0.01) with increasing TDDGS in the diet, whereas digestibility of DM, crude protein and fat responded quadratically (P &lt; 0.01). Starch digestibility decreased and ADF digestibility increased linearly (P &lt; 0.01), but there was no treatment effect on NDF digestibility (P &gt; 0.29). Total nitrogen, total phosphorus and soluble phosphorus excretion increased (P &lt; 0.01) with increasing TDDGS. In conclusion, TDDGS can be fed in place of barley grain at levels up to 60% in diets for lambs without adverse affects on growth performance or carcass traits, but this practice will lead to an increase in N and P excretion into the environment.Key words: Lamb, digestibility, triticale distillers grains, performance, carcass characteristics

Development of Analysis Condition and Detection of Volatile Compounds from Cooked Hanwoo Beef by SPME-GC/MS Analysis

The current study was designed to optimize solid phase microextraction (SPME)-GC-MS conditions for extraction and analysis of volatile components for Hanwoo beef and to establish a tentative database of flavor components. Samples were taken from Hanwoo longissimus muscle (30 mon old steer, <TEX>$1^+B$</TEX> carcass grade) at 24 h postmortem. Results indicated that the optimum adsorption time for <TEX>$75{\mu}m$</TEX> CAR/PDMS fiber was 60 min at <TEX>$60^{\circ}C$</TEX>. Thermal cleaning at <TEX>$250^{\circ}C$</TEX> for 60 min was the best practice for decontamination of the fiber. A short analysis program with a sharp oven temperature ramp resulted in a better resolution and higher number of measurable volatile components. With these conditions, 96 volatile compounds were identified with little variation including 22 aldehydes, 8 ketones, 31 hydrocarbons, 12 alcohols, 8 nitrogen- and sulfurcontaining compounds, 5 pyrazines and 10 furans. A noticeable observation was the high number of hydrocarbons, aldehydes, ketones, alcohols and 2-alkylfurans which were generated from lipid decomposition especially the oxidation and degradation of unsaturated and saturate fatty acids. This implies that these compounds can be candidates for flavor specification of highly marbled beef such as Hanwoo flavor.

Consumer responses for tenderness and overall impression can be predicted by visible and near-infrared spectroscopy, Meullenet–Owens razor shear, and Warner–Bratzler shear force

Beef ribeye rolls (n=40) from Select, low Choice, top (upper 2/3) Choice, and Prime quality grade carcasses were used to determine the relationship of visible and near-infrared spectroscopy (VNIR) reflectance, Warner-Bratzler shear force (WBSF), and Meullenet-Owens razor shear (MORS) with consumer responses for tenderness and overall impression. Steaks (2.54 cm) were cut and assigned to either 14 or 28d aging (n=4/aging period). Reflectance in the VNIR spectrum was measured 1d from the box-date no less than 30 min after cutting, and prior to aging. The steak used for VNIR measurement was designated for WBSF and MORS measurement, whereas three adjacent steaks were cooked for evaluation by a consumer panel (n=240 members). Steaks from the Select-grade ribeye rolls had the greatest (P=0.06) WBSF values and lower (P<0.05) overall impression scores than those from top Choice and Prime quality grades. Consumer panelists evaluated steaks aged 28 d as more tender (P<0.05) than those aged 14 d. The relationship of mechanical tenderness measurements were higher with consumer panel responses for tenderness than with overall impression, and those relationships were stronger for the Select grade than for quality grades with higher degrees of marbling. The 2nd derivatives of VNIR measurements were more successful at predicting consumer panel responses of tenderness and overall impression than WBSF and MORS; thus, VNIR methodology was less invasive and more predictive than other, more traditional tenderness measurements.

Growth performance and carcass characteristics of indigenous Mukota pigs of Zimbabwe

Carcass quality characteristics are essential in affecting grading and revenue that pig producers realize. No information is available on the grading of carcasses in indigenous Mukota pigs of Zimbabwe. The objective of this study was to determine the influence of genotype (Mukota and Large White x Mukota) and sex on post-weaning growth performance and carcass traits of pigs fed maize cob-based diets. All pigs were weighed at 2-week intervals to estimate average daily gain, dressing percentage (DP), and carcass lengths. Backfat thickness was also measured. Males had higher body weight gains than females (P < 0.05). Growth rates for Mukota (0.31 +/- 0.010) and crossbred (0.41 +/- 0.030) pigs were lower in the cool season than the other seasons (P < 0.05). Body weights were consistently higher in the crossbred than in the Mukota pigs (P < 0.05). Mukota pigs showed a peak growth between 12 and 14 weeks post-weaning (P < 0.05). The DPs were 0.70 and 0.73 for the Mukota and crossbred pigs, respectively (P < 0.05). Crossbred pigs had longer (P < 0.05) carcasses than Mukota (655.5 +/- 1.68 versus 507.2 +/- 0.92 mm). Although there were no differences in the backfat thickness between males and females of the crossbred pigs, Mukota males had thicker backfat than the females (P < 0.05). Crossbreeding is, therefore, significant in improving carcass grades of Mukota pigs.

주부의 돼지고기 구매행태에 관한 연구

본 연구는 주부 253명을 대상으로 학력별, 생활지역별 및 연간소득별로 구분하여 국내 외산 돼지고기의 선호도와 구매행태를 조사한 결과로 국내산과 외국산 선호점수는 5점 중 각각 평균 <TEX>$4.07{\pm}0.81$</TEX>점과 <TEX>$2.21{\pm}0.96$</TEX>점이었다. 소비자가 돼지고기 중 가장 선호하는 부위는 삼겹살이었고 (56.4%), 구매장소는 대형유통점에서 주로 구입하고 있었으며 (45.4%), 구매처를 선택할 때는 품질신뢰도를 중요시하였다(40.2%). 소비자는 1회 포장 적정단위로 600 g을 선호하였고 (54.6%), 돼지도체등급제의 인지도는 <TEX>$2.97{\pm}0.88$</TEX>점, 그리고 브랜드 돼지고기의 신뢰도는 <TEX>$3.47{\pm}0.60$</TEX>점으로 나타나 다양한 선호도와 구매행태를 보였다. This study was carried out to investigate consumer's purchase behaviors of pork. Questionnaires from a total of 253 housewives were analyzed Jan. to Feb. 2008. The average of preferences for domestic and imported pork were <TEX>$4.07{\pm}0.81$</TEX> and <TEX>$2.21{\pm}0.96$</TEX> scores of 5 points, respectively. Consumers (56.4%) liked belly of pork very much. Consumers (45.4%) purchased a great deal of pork in big discount mart. Consumers (40.2%) responded that they indicated quality reliability as the choice factors for determination of purchasing pork. Respondents (54.6%) hoped the wrapping pork pack of 600 g. The evaluation of the perception for carcass grading system and quality reliability for brand-pork averaged <TEX>$2.97{\pm}0.88$</TEX> and <TEX>$3.47{\pm}0.60$</TEX> scores of 5 points, respectively.

Effects of environmental factors on breast blister incidence, growth performance, and some biochemical indexes in broilers

SUMMARY Breast blisters (BB) are an important factor affecting the carcass grade of broilers. To investigate the effects of floor type, stocking density, and sex management on the incidence of BB, an orthogonal design with 3 factors and levels [L9(3 4 )] was used in this study. A total of 324 Arbor Acre broilers, 21 d of age, were randomly allocated into 9 groups with 2 replicates each, and were raised in cages with different floor types (wire netting, plastic slats, and bamboo slats), at different densities (17, 14, and 11 broilers/m 2 ), and with different sex management (males, females, and mixed sexes). Effects of these factors on the incidence of BB, growth performance, and some biochemical indexes were studied for birds from d 21 to 42. The results showed that floor type had the greatest effect on the incidence of BB compared with stocking density and sex management. The incidence of broiler BB was significantly higher in cages with wire netting than in those with plastic or bamboo slats (P 0.05). Birds on plastic slats had higher total antioxidant capability values than those on wire netting or bamboo slats (P < 0.05). Malondialdehyde content of birds in the wire netting group was higher than those of birds on plastic and bamboo slats (P < 0.05). In this study, floor type was the main environmental factor affecting the incidence of BB in broilers, compared with density and sex management. Results suggest that the increased serum levels of lactic acid and malondialdehyde are involved in the development of BB.

Relationship of Slaughter Age and Carcass Traits of Hanwoo Cattle

Two experiments were carried out to investigate the relationship of slaughter age and carcass traits of Hanwoo cattle. A total number of 11,284 heads of cattle (4,624 bulls, 6,120 steers, and 540 females) were used in the experiment (Exp.) 1. In the Exp. 2, 3,887 heads of steers slaughtered at age of 24-36 mon were used. After 24 h post-slaughter chilling, the carcasses were weighed and evaluated by an official grader of carcass traits according to the Korean carcass grading standard. Backfat thickness was the main variable in yield index and grade whereas marbling score was the main variable in carcass quality grade. Meat color was an important factor affecting carcass quality grade of bulls; fat color was an important factor affecting those of steers and females; and maturity was an important factor affecting that of females. After 24-mon-old, extension of slaughter age did not automatically increase the quantity and quality of meat. However, 29 mon of age can be regarded as the optimum time to slaughter steers to attain the highest take home money for farmers.

경제성 관련 계육 도체 결함과 축산물등급사에 의한 품질 A등급의 상관관계

본 연구는 2007년 9월 1일부터 2008년 8월 31일까지 1년간을 공시기간으로 총 597농가에서 출하된 육계를 각 농가당 100수씩 무작위로 선정하여 총 59,700수의 계육도체를 축산물등급판정사가 등급판정한 결과를 기초로 계육의 등급판정 대상 각 항목에 따른 품질 A등급 출현율의 상관관계를 알아보고자 실시하였다. 출하일령에 따른 닭의 체중은 31-33일령 사이에 증가되고 있으며, 35일령 이후에는 출하 시점에 체중이 감소하는 경향을 보였다. 계절에 따른 품질등급에서 일당증체량과 A등급 출현율은 가을철에 높게 관찰되었고, 멍/파계 비율과 비정상계의 비율은 겨울철에 높게 관찰되었다(p<0.05). 경제성 관련 결함은 출하일령이 증가함에 따라 발생 빈도가 높아지고, A등급 출현율과의 상관관계는 외관(-0.88), 외상(-0.48), 변색(-0.12)의 순으로 높은 부의 상관관계가 나타났다. 비경제성 관련 결함과 A등급 출현율은 깃털(-0.16), 이물질(-0.22) 및 도체처리(-0.32)에서 부의 상관관계를 나타내었다. 품질 A등급 출현율과 결함수 합계와는 높은 부의 상관관계(-0.93)를 나타내었으며, 특히 경제성 관련 결함수와는 -0.91로 축산물등급판정사의 A등급 판정은 추후 경제성 관련 항목과 매우 밀접한 연관이 있음을 알 수 있었다. 이상의 결과를 종합해보면 축산물등급판정사의 등급판정 결과를 농가의 사양정보로 활용하여 생산성 증대에 기여할 수 있으며 출하 시 적정 가격정산에 이용이 가능하다고 생각된다. 또한 고품질 계육에 대한 소비자의 선택권 부여와 우수농가 보상에 활용될 수 있으리라 판단된다. To investigate the relationship between the carcass defects considered by a meat grader and quality grade A, a total of 59,700 broiler carcasses, which were reared from September 1, 2007 to August 31, 2008 and randomly selected from 597 broiler farms with 100 broilers in each farm, were graded by a meat grader using the Korean meat grading system. The average slaughter weight of the broilers increased at the 31- to 33-d age but decreased after the 37-d age. The average daily gain to grade A ratio of the broilers was highest in autumn, and the bruises, flesh blemishes, and abnormalities of the carcasses were found to have been most frequent in winter (p<0.05). The number of economical defects (EDs) increased with the increase in the slaughter age, and the correlation coefficients of the EDs and grade A were -0.88, -0.48, and -0.12 in terms of the conformation, exposed flesh/cuts/tears, and skin discolorations of the carcasses, respectively. The correlation coefficients of the non-economical defects (NEDs) and the grade A of the broiler carcasses were -0.16, -0.22, and -0.32 in terms of the feathers, alien substances, and carcass treatment, respectively. The total number of defects (EDs + NEDs) and the grade A were highly correlated (-0.93), and in particular, the correlation between the grade A and the EDs was -0.91. It can be deemed that the grade A from a meat grader is highly correlated with the EDs. Therefore, the results suggest that broiler carcass grade evaluation using a meat grading system can provide direct information on profits in the market. The resulting carcass grade of broilers can also provide the information needed to decide on a proper incentive for a farm that has attained a good quality grade.

A survey of beef carcass quality and quantity attributes in Mexico1

The objective of the present study was to evaluate quality and yield attributes of Mexican beef carcasses to serve as a benchmark for production in the Mexican beef cattle industry. Seven packing plants were surveyed nationwide. Carcass yield and quality traits were assessed in the cooler at approximately 24 h postmortem. Results indicated that around 90% of the beef slaughter population in Mexico has a strong Bos indicus genetic background. Moreover, 71.6% of the surveyed cattle are presented for slaughter at a BW between 400 and 500 kg. Chilled carcass weight was between 220 and 340 kg in 88.9% of the surveyed population. According to European beef carcass grading standards, carcass conformation varied from poor to good in 82% of the carcasses, whereas in 17.8% the conformation was very good or excellent. In 60.7% of the surveyed carcasses the KPH was 2% or less. The subcutaneous fat depth was 1 cm or less in 90% of the carcasses. In 71.8% of the carcasses the LMA was of 80 cm(2) or less, whereas only 8.6% had LMA values of 90 cm(2) or greater. Carcass maturity score USDA B(100) or less was found in 92.4% of the evaluated carcasses, whereas 28.5% were graded as USDA A(100)/B(00). A total of 93.6% of the sample had marbling scores of 300 or less, corresponding to the categories slight, practically devoid, or traces. Only 12.9% of the carcasses exhibited a yellow fat cover. In the remaining 87.1% the fat cover was white or beige. The backfat layer was uniform in 43.2% of the carcasses, whereas 55.9% had an uneven fat cover. Information from this survey provided data that could serve as a means to develop a yield and quality evaluation program that can be further developed into a value system for Mexican beef carcasses and live cattle.

Effects of zilpaterol hydrochloride feeding duration and postmortem aging on Warner-Bratzler shear force of three muscles from beef steers and heifers

To determine the effects of zilpaterol hydrochloride (ZH; 6.8 g/t on 90% DM basis) feeding duration (0, 20, 30, and 40 d) on Warner-Bratzler shear force (WBSF) of longissimus lumborum (LL), triceps brachii (TB), and gluteus medius (GM) muscles, beef from feeding trials was collected and shipped to participating universities. Animals were slaughtered at commercial processing facilities across the United States. Strip loin, shoulder clod, and top sirloin butt subprimals (IMPS 180, 114, and 184, respectively) were obtained from a portion of USDA Choice and Select grade carcasses for WBSF using standardized procedures and equipment. Feeding ZH increased (P < 0.001) LL WBSF values of USDA Choice and Select steaks. A significant linear contrast existed for both quality grades, indicating increased WBSF values were associated with longer feeding durations. Increased postmortem aging decreased LL WBSF of control and treated steaks. Postmortem aging from 7 to 21 d decreased LL WBSF values by 17.6 and 16.4% for USDA Choice and Select steaks, respectively. The percentage of LL steaks from ZH-supplemented cattle with a WBSF value <4.5 kg was significantly less than control steaks for both quality grades. Postmortem aging from 7 to 21 d postmortem increased (P < 0.001) the percentage of LL Choice and Select steaks with WBSF <4.5 kg for all ZH feeding durations. Feeding ZH for 20, 30, or 40 d increased (P < 0.01) WBSF of USDA Choice TB and GM steaks compared with 0-d controls. Feeding ZH for 0, 20, and 40 d had a similar effect on WBSF of USDA Select GM steaks, and produced lesser values than steaks from cattle fed ZH for 30 d. Feeding ZH for 20, 30, and 40 d had no effect on WBSF values of USDA Select TB steaks. However, the 20-, 30-, and 40-d duration produced WBSF values greater (P < 0.05) than control (0 d) TB steaks. Postmortem aging decreased (P < 0.05) WBSF of USDA Choice and Select TB and GM steaks, but the percentage improvement in WBSF attributed to aging was less than observed for LL steaks. The results of this study indicate feeding ZH increased (P < 0.001) WBSF of LL, TB, and GM. The ZH feeding also decreased (P < 0.01) the percentage of steaks with WBSF <4.5 kg regardless of US quality grade, whereas postmortem aging increased (P < 0.01) the percentage of US Choice and Select steaks with WBSF <4.5 kg. Finally, postmortem aging reduced (P < 0.05) WBSF of steaks from ZH-supplemented beef cattle.