The relationship between the chemical composition of the carcass and the fatty acid composition of intramuscular fat and backfat of several pig breeds slaughtered at different weights

Pigs of Belgian Landrace (B), Duroc (D), Hampshire (H), and Pietrain (P) breeds were slaughtered at 90, 110 and 130 kg body weight (BW) and the carcass chemical composition and fatty acid profiles of intramuscular fat of loin and backfat were determined. The carcass of Pietrain pigs had a higher concentration of protein and less fat than of B, D and H breeds. In tissues, the PUFA:SFA ratio was lower in the heavier (130 kg BW) than in lighter pigs (90 and 110 kg BW). This feature was higher in P pigs compared with the other breeds. The backfat had a higher concentration of PUFA:SFA ratio than intramuscular fat. The PUFA n− 6:n− 3 ratio was not affected by the breed and weight of pigs, but it was lower in backfat than in longissimus muscle fat. The protein concentration in the carcass was positively related to PUFA and negatively to SFA concentration in tissues.     

Relationships between carcass quality parameters and genetic types

It is important for the meat industry, including pig farmers and breeding companies, to know the composition of the carcass including the proportions of the different commercial cuts when making decisions on the type of pigs to be produced and marketed. Carcass composition is influenced significantly by the genotype of the animals. The aim of this work was to characterise carcasses from five different pig genotypes, by means of the quantification and comparison of their physical composition. Carcasses from 500 gilts from five different genetic types were studied. These lines were based on the following breeds: Large White, Landrace, Duroc, Piétrain and a Meishan synthetic population developed from a cross with a Large White based line. Measurements were taken in the carcasses directly with a ruler and with the Fat-O-Meat'er. The carcasses were cut following the European reference method and the four main joints were dissected. Carcasses from the Piétrain based line, which was halothane negative, presented the highest killing-out (83.34%) and were the shortest (81.81cm). The Piétrain based line was also the leanest and the Meishan based line the fattest. The highest proportion of ham (270.9g/kg) and the lowest proportion of belly (97.97g/kg) were found in the Piétrain line. The proportion of lean in all of the dissected cuts was higher in carcasses from this line while the Meishan line presented the highest proportions of intermuscular fat in all of the pieces. Carcasses came from the Piétrain line received the highest conformation scores and they were leaner and with better ham yield.     

Relationship of physically separable lean with chemical lean in pig carcasses

This study was conducted to examine the relationships between 'physically separable lean' (carried out by the Kulmbach reference technique) and 'lean' determined by moisture or lipid analysis (called chemical lean). Five major cuts (ham, shoulder, loin, belly and neck), originating from the Hungarian cross-breed 'Hungahyb', were dissected and the weights recorded. The moisture and lipid contents of three tissue groups (lean, intermuscular fatty tissue and remainder) were determined by common laboratory methods. Adequate estimators (predictors) were then developed for the assessment of standardized or non-standardized lean content in the 'boneless cut' (without skin and subcutaneous fatty tissue). It was shown that the concept of moisture-standardized lean is analogous to that of the fat-standardized one. It appears that unbiased estimators could be obtained if the interdependences between the chemical composition (moisture or lipid content) of the lean, the 'residue' (intermuscular fatty tissue + remainder) and that of the 'boneless cut' are included in the respective equations. If these interdependences are neglected and only the corresponding means are used in these equations, biased estimates have been obtained for the standardized or non-standardized lean content in the 'boneless cut'. Difficulties arising at practical application of these concepts are also discussed in this paper.     

肌内脂肪与背最长肌肉质、脂肪酸组成的关系

研究肌内脂肪（IMF）含量与肉质以及脂肪酸含量和组成比例之间的关系。以北京黑猪背最长肌（n=20）为实验材料,测定肌内脂肪含量、肉质以及脂肪酸含量和组成。结果显示,肌内脂肪含量与滴水损失呈显著正相关（p<0.05）,与蒸煮损失、剪切力、肉色的相关性不显著（p>0.05）。随着肌内脂肪含量升高,除长链多不饱和脂肪酸(C_20:3n6、C_20:4n6)以外的大多数脂肪酸含量增加,相对比例也上升;多不饱和脂肪酸的含量增加,但是相对比例下降;长链多不饱和脂肪酸的含量和相对比例都降低。随着肌内脂肪含量的升高,饱和脂肪酸（SFA）和单不饱和脂肪酸（MUFA）的含量升高,回归方程斜率分别为197.3和248.31,多不饱和脂肪酸（PUFA）增加的幅度不大,回归方程的斜率为11.43。结果提示:肌内脂肪含量较低时（本实验平均值2.86%）,对肉质的影响不显著。随着肌内脂肪含量升高,总脂肪酸含量（TFA）增加,主要归因于SFA和MUFA含量的增加。PUFA的含量相对稳定,受肌内脂肪含量变化的影响较小。      

我国部分典型植烟区土壤腐殖质组成特征及其与部分土壤因子的关系

分析了我国部分典型植烟区土壤腐殖质组成特征及其与部分土壤因子的关系,结果表明:(1)在所考察的典型烟叶产区中,植烟土壤腐殖质碳量集中分布在10-20 g/kg之间,平均为15.25 g/kg.胡敏酸比例、富里酸比例、胡敏素比例分别分布在11.05%-32.15%、12.00%-36.28%、38.43%-68.23%之间,胡富比值集中分布在0.7-1.3之间.(2)腐殖质碳量以东南烟区显著较高,黄淮烟区显著较低;胡富比以东南烟区显著较高,胡富比值达1.14,其它烟区土壤胡富比小于1.(3)水稻土腐殖质及组分碳量均最高,紫色土、红壤、棕壤次之,褐土最低.水稻土腐殖化程度显著较高,棕壤和红壤腐殖化程度显著较低.(4)土壤pH与腐殖质组成整体呈显著负相关关系.土壤的富里酸比例越低、胡富比越高,土壤碱解氮含量呈升高趋势.     

Effect of source of dietary fat on pig performance,carcass characteristics and carcass fat content,distribution and fatty acid composition

Seventy gilts were used to compare the effect of including 10% tallow (T), high-oleic sunflower oil (HOSF), sunflower oil (SFO), linseed oil (LO), a fat blend (FB), or an oil blend (OB) in finishing diets vs. feeding a semi-synthetic diet with no added fat (NF) on pig performance, carcass traits and carcass fatty acid (FA) composition. Carcasses from SFO-fed gilts had greater fat and lower lean compositions than carcasses from T-fed gilts. Gilts fed NF had greater loin fat than FB-fed gilts, and greater flare fat, loin intermuscular fat and fat:lean than T-fed gilts. Bellies from NF-fed gilts had lower lean and higher intermuscular fat and fat:lean than other diets except HOSF. Fat source had minor effects on animal performance, carcass characteristics and carcass fat content and distribution, whereas feeding NF resulted in carcasses and major cuts with higher fat content. Diets rich in polyunsaturated FA (PUFA) did not reduce fat deposition in separable fat depots with respect to monounsaturated FA (MUFA) and saturated FA (SFA). Carcasses from gilts fed NF had a high degree of saturation (40.6% SFA) followed by carcasses of T- and FB-fed gilts. Feeding HOSF, SFO and LO enriched diets elevated the percentages of MUFA (56.7%), n−6 (30.0%) and n−3 (16.6%) PUFA, respectively, whereas carcasses from gilts fed OB had greater percentages of n−3 FA (14.8% n−3, 0.9% EPA, 1.0% DPA, 3.1% DHA) than gilts fed FB (6.72% n−3, 0.1% EPA, 0.4% DPA, 0.1% DHA).     

Dual X-ray absorptiometry accurately predicts carcass composition from live sheep and chemical composition of live and dead sheep

Fifty merino wethers (liveweight range from 44 to 81kg, average of 58.6kg) were lot fed for 42d and scanned through a dual X-ray absorptiometry (DXA) as both a live animal and whole carcass (carcass weight range from 15 to 32kg, average of 22.9kg) producing measures of total tissue, lean, fat and bone content. The carcasses were subsequently boned out into saleable cuts and the weights and yield of boned out muscle, fat and bone recorded. The relationship between chemical lean (protein+water) was highly correlated with DXA carcass lean (r(2)=0.90, RSD=0.674kg) and moderately with DXA live lean (r(2)=0.72, RSD=1.05kg). The relationship between the chemical fat was moderately correlated with DXA carcass fat (r(2)=0.86, RSD=0.42kg) and DXA live fat (r(2)=0.70, RSD=0.71kg). DXA carcass and live animal bone was not well correlated with chemical ash (both r(2)=0.38, RSD=0.3). DXA carcass lean was moderately well predicted from DXA live lean with the inclusion of bodyweight in the regression (r(2)=0.82, RSD=0.87kg). DXA carcass fat was well predicted from DXA live fat (r(2)=0.86, RSD=0.54kg). DXA carcass lean and DXA carcass fat with the inclusion of carcass weight in the regression significantly predicted boned out muscle (r(2)=0.97, RSD=0.32kg) and fat weight, respectively (r(2)=0.92, RSD=0.34kg). The use of DXA live lean and DXA live fat with the inclusion of bodyweight to predict boned out muscle (r(2)=0.83, RSD=0.75kg) and fat (r(2)=0.86, RSD=0.46kg) weight, respectively, was moderate. The use of DXA carcass and live lean and fat to predict boned out muscle and fat yield was not correlated as weight. The future for the DXA will exist in the determination of body composition in live animals and carcasses in research experiments but there is potential for the DXA to be used as an online carcass grading system.     

Texture of cooked potato II.—Relationships between intercellular adhesion and chemical composition of the tuber

In the variety Majestic, statistically significant relationships were found between intercellular adhesion and the levels of tuber starch, amylose, polyuronide, calcium and magnesium. It is suggested that the relationship between intercellular adhesion and a particular constituent may be modified by the levels of the other constituents. a mechanism is proposed for the action of amylose in influencing intercellular adhesion. the differences in intercellular adhesion, and in the levels of the various intrinsic factors, were produced by feeding plants different nutrient solutions (various chloride/nitrate ratios) or by maintaining different moisture regimes.     

猪胴体瘦肉率仪器测定值与生猪品种等级的关系研究

使用PG100瘦肉率测定仪,对四种不同品种等级的生猪屠宰后的胴体的瘦肉率进行了测定,并与精确分割试验测定的瘦肉率进行了比较。结果表明使用仪器测定的瘦肉率指标,能够较好地反映生猪品种等级的优劣,可以用于生猪屠宰过程中的智能分级。     

The relationship between carcass, meat and eating quality of three pig genotypes

The relation between the intrinsic carcass and meat quality and the organoleptical characteristics of three genotypes of pigs was studied. In total 411 pigs, consisting of 121 BL-genotype pigs, 115 hybrids (Seghers Hybrid) and 175 Large White-genotype pigs, were screened. Slaughter day and genetic background had a great impact on the intrinsic meat quality parameters. The factor 'slaughter day' implies the stunning method besides the total specific transport and slaughter conditions. Whatever the genetic background is, halothane susceptibility is obviously the crucial factor. Selection against the halothane gene positively influences the intrinsic and sensory meat quality parameters. This study also suggests that an increase in the intramuscular fat content, if desirable in the interest of the sensory meat quality, can be achieved without deterioration of the zoo-technical performance and the carcass quality of the pigs.     

猪胴体加工工艺与设备

根据猪胴体加工工艺,重点介绍在胴体加工过程中的输送、旋毛虫检验、同步检验、劈半等工艺及设备,同时,笔者结合多年的实践经验,提出了一些见解及操作方法.     

Prediction of carcass composition in the rabbit

Carcass composition of two synthetic rabbit breeds was predicted from retail cuts and external measurements by using regression equations. Breed R has a higher adult weight and reaches slaughter weight 1 week before breed V. Sixty rabbits of each breed were slaughtered when they (approximately) reached the Spanish commercial liveweight of 2kg. The carcasses were measured and retailed according to the norms of the World Rabbit Scientific Association. Rabbit carcass composition is well defined by meat percentage of the commercial carcass and ratio meat bone . External measurements on the carcass, retail cuts and meat of retail cuts or muscular masses are all bad predictors of carcass meat percentage or ratio meat bone (R(2) < 0.53). The ratio meat bone of the hind leg can give reasonable predictions for carcass meat percentage and meat bone ratio (R(2) = 0.60 and 0.69). Dissectible carcass fat weight and dissectible carcass fat percentage can be predicted by the perirenal fat weight (R(2) = 0.77 and 0.69). Fat depots had a low predictive power for fat percentage of the dissected meat in the half carcass.     

Prediction of carcass composition and individual carcass cuts of Japanese Black steers

The objective of this study was to develop equations to predict carcass tissue weights and percentages and boneless carcass non-trimmed cut weights by using the cold carcass weight (CCW) and three other traits at the 6–7th rib section, which are routinely collected in carcass markets in Japan. Carcasses from 94 Japanese Black steers were used for the multiple regression analysis with a stepwise procedure and a novel Least Absolute Shrinkage and Selection Operator (LASSO). The accuracies of prediction (R²) and RMSEs for the carcass tissue and cut weights were similar between the two procedures. In contrast, LASSO appeared to be the better procedure for predicting carcass tissue percentages. The longissimus muscle area and subcutaneous fat thickness were the important predictors for the lean percentage in the stepwise procedure, and CCW was additionally selected when the LASSO procedure was used.     

USDA yield grades and various carcass traits as predictors of carcass composition

Twenty-five carcasses from each of three breedtypes (Brahman, Angus and Brahman × Angus) were physically separated into fat, lean and bone. Several muscles from the round and the femur were used to derive equations to predict carcass composition and muscle-to-bone ratio. The femur (as a percentage of the carcass) was shown to predict percentage carcass bone with 90% accuracy. All of the muscles studied were highly related to total carcass lean but the percentage of carcass as M. biceps femoris was the best single muscle indicator of carcass lean of the muscles studied. More variation in carcass lean could be accounted for by a multiple regression equation, involving all four muscles studied, than by any single muscle. M. biceps femoris-to-femur ratio was found to predict carcass muscle-to-bone ratio with a high degree of accuracy. The USDA yield grades were found to be reliable indicators of carcass composition. A two-variable equation involving adjusted fat thickness and biceps femoris accounted for 88·6% of the variation (RSD = 1/·64) in percentage of carcass as separable lean.     

Effects of sometribove on performance, carcass composition, and chemical blood characteristics of dairy calves.

Ten intact male Holstein calves averaging 75 kg of BW and 59 d of age were used to study the effects of daily injections of 0 (control) or 10 mg of sometribove (recombinant methionyl bST) for 6 wk on performance, health, carcass composition, N metabolism, chemical blood characteristics, and hormone profiles. Average daily gain, feed intake, feed:gain ratio, and height at withers, hip, and hock were not influenced by bST. Carcasses from bST-treated calves contained 5% more protein and 36% less lipid than controls. Circulating concentrations of Ca, P, glucose, urea N, alkaline phosphatase, creatine phosphokinase, insulin-like growth factor-I, and insulin were not affected by bST. Packed cell volume was decreased about 7% (29.9 vs. 32.4%) in the bST calves. Hormone injection did not adversely affect health of the calves as measured by body temperature and by pulse and respiration rates. The most profound effects of sometribove were a reduction in carcass lipid and an increase in body proteins. These effects may be of some practical importance when leanness of carcass is desirable.     

Estimation of lamb carcass composition from measurements of the speed of ultrasound in the soft tissues of live animals and carcasses

The application of the velocity of sound (VOS) technique to lamb carcasses in a previous study (Fisher & Page, 1986) measured composition at a hind limb and neck site but was not as precise as fat scores in predicting lean proportion. This study examines VOS measurements made at sites in the hind limbs and along the vertebral column in live sheep and carcasses. A group (A) comprising five breeds of males and females (n = 61) and a sub-group (B) of Scottish Blackface castrated males (n = 34) were studied, and the reciprocal velocity of ultrasound (RV) was measured on the live sheep immediately behind the shoulder and over the last rib using a fixed-distance transducer assembly operating at 5 MHz, and in the hind limbs at 2·25 MHz using the apparatus described by Miles et al. (1984). Corresponding measurements were made on the carcasses which were classified by a Meat and Livestock Commission fatstock officer and then dissected. Standard deviations of lean proportion were 4·48% (A) and 3·39% (B). The residual standard deviations (rsds) for groups A and B respectively were obtained using the following predictors: live mass (LM) 4·27% and 2·96%; LM + breed (B) 3·08% (group A only); LM + mean RV 2·36% and 2·07%; LM + B + mean RV 1·99% (group A only). Using carcass measurements: carcass mass (CM) 4·25% and 2·90%; CM + MLC fat score 2·99% and 2·12%; CM + RV last rib 2·89% and 2·02%. These data show that VOS measurements through dorsal sites of live sheep provide encouragingly precise estimates of carcass lean proportion. For carcasses, dorsal sites provide a less precise estimate of carcass lean but when carcass mass is included in multiple regression the precision of the correlation is comparable with that of multiple regression of fat score with carcass mass.     

The yield and carcass chemical composition of impala (Aepyceros melampus), a southern African antelope species

This investigation analyses the commercial carcass yields and chemical composition of impala (Aepyceros melampus). The potential of this species for the export market is also discussed. Impala rams (eight) and ewes (eight) cropped commercially in Zimbabwe were found to have a similar dressout proportion (580 g kg⁻¹), although the males had a heavier live weight (49.4 ± 4.606 kg) than the females (33.5 ± 3.417 kg). Sexual dimorphism was shown, with the males having significantly (p < 0.01) heavier necks (69 ± 5.47 g kg⁻¹) and forequarters (279 ± 3.79 g kg⁻¹) than the females (51 ± 1.70 and 259 ± 2.15 g kg⁻¹ respectively) when expressed as a proportion of cold carcass weight (27.6 ± 2.551 and 19.0 ± 1.960 kg for males and females respectively). No sexual effects (p > 0.2) were found in the mean chemical proximate composition of the 9‐10‐11 rib cut for the moisture (724.0 ± 14.00 g kg⁻¹ pooled sample), protein (238.3 ± 7.46 g kg⁻¹ pooled sample) and ash (21.2 ± 3.74 g kg⁻¹ pooled sample) contents. The females had a statistically higher (p = 0.0197) mean total lipid content (33.9 ± 1.705 g kg⁻¹) than the males (24.5 ± 3.171 g kg⁻¹). This investigation occurred at the end of the impala rut season, a period when the rams not only consume less feed but also expend more energy owing to strenuous activities in fighting for and maintaining a harem. © 2000 Society of Chemical Industry     

Relationship between the chemical composition and the biological activities of food melanoidins

The relationship between the chemical composition and the biological activities of food melanoidin-rich fractions was investigated. Melanoidin-rich fractions were extracted using ultrafiltration (a 10 kDa cut-off) from coffee, barley coffee, dark beer, and traditional balsamic vinegar. All the food melanoidin-rich fractions were formed mainly of carbohydrates, phenolic compounds, and proteins. In dark beer, barley coffee, and traditional balsamic vinegar melanoidins, glucose was the most abundant sugar incorporated into melanoidins. Coffee melanoidins contained the largest amount of phenolic groups, followed by traditional balsamic vinegar melanoidins. The radical scavenging, Fe²⁺-chelating, and heme binding abilities of food melanoidins were investigated under gastric conditions. The melanoidinrich fraction extracted from coffee was the most active, showing the highest radical scavenging, Fe²⁺-chelating, and heme binding activities, compared to barley coffee, dark beer, and traditional balsamic vinegar. The radical scavenging and Fe²⁺-chelating abilities were assigned to the phenolic groups present in food melanoidins.     

The relationship of carcass measurements to carcass composition and intramuscular fat in Spanish beef

Forty beef carcasses were classified for conformation and fatness. Besides, carcass weight, fat thickness (FT), carcass dimension, marbling by computer image analysis and ultrasound readings was recorded to complement grading. For predicting intramuscular fat (IMF) content, FT, number of intramuscular flecks and conformation increased R²-value from 0.19 to 0.64 compared to conformation alone. For visual marbling, ultrasound readings and thoracic depth (TD) increased the R²-value from 0.24 to 0.57 compared to fatness score (FS). The best variables for predicting weight of fabricated subprimals were carcass weight or compactness which is a function of carcass weight (R² between 0.94 and 0.63). Fatness score was poorer than FT for predicting yield of subprimals cuts from round (R² = 0.16 vs. 0.50) and ultrasound readings for less valuable subprimals (R² = 0.31 vs. 0.39). These results showed that other variables could be used in combination with carcass fatness or conformation to achieve a more accurate estimation of fat and carcass yield.     

Comparison of the lipid content and fatty acid composition of intermuscular and subcutaneous adipose tissues in pig carcasses

Lipid contents and compositions were measured in 35 pigs from seven genotype-sex groups with large variations in body composition. The animals were slaughtered at 115kg live weight, and the left side was separated into four primal cuts: belly, ham, loin, and shoulder. Samples of adipose tissues were taken from flare fat and from subcutaneous and intermuscular adipose tissues in each of the four cuts. In the loin, the outer and inner layers of subcutaneous adipose tissue were sampled separately. Total lipid content was lower in intermuscular than in subcutaneous adipose tissue. It was the highest in flare fat. There was a gradient of decreasing unsaturation from the outer layer of subcutaneous adipose tissue, to the inner layer, to intermuscular adipose tissue, to flare fat. The monounsaturated fatty acid concentrations followed the same pattern. There was a statistically positive correlation between the linoleic acid concentration of the different adipose tissues and the half carcass muscle content.