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1. 1. The phospholipids of pig adipose tissue (loin back fat) have been isolated and the amount and fatty acid composition of each determined. 2. 2. The positional distribution of fatty acids in the phosphatidyl choline, the major component (61% of the total phospholipid), was determined after hydrolysis with phospholipase A 2 . 3. 3. Diglyceride acetates were prepared from the phosphatidyl choline and separated into simpler molecular species by silver nitrate chromatography and by high temperature gas-liquid chromatography. The results differ markedly from those reported for the phosphatidyl choline from other pig tissues.

31 lamb carcasses were split after slaughter and one side of each had pre-rigor tension applied to the longissimus muscle by weighted or mechanical methods. Warner-Bratzler shear values were obtained on each of three core positions within rib and within loin chop samples from each nontensioned and tensioned side. Differences in shear values between cores were significant (P < 0.001), and the interactions of muscle location, tension treatment and core were also significant (P < 0.001). The lateral position was the least tender in rib chops while the dorsal position was least tender in loin chops of the nontensioned sides. Pre-rigor tension made core positions more uniform in tenderness in the rib chops, while considerable tenderness variation persisted in tensioned loin chops.

Data from a swine breed development project provided estimates of the genetic correlation among six performance and carcass traits. The data from the new breed, called Managra, were obtained over a 7-year period. Most genetic relationships examined were such that selection for improvement of one trait would yield a favorable improvement in another. Both carcass backfat and live backfat probe were found to be negatively correlated with area of loin eye and length of carcass. A positive genetic correlation was found between post-weaning daily gain and loin eye area. A high positive genetic correlation was found between birth weight and loin eye area. An unfavorable association involved a positive genetic correlation between birth weight and backfat.Correction factors for effect of carcass weight on the magnitude of carcass trait measurements and differences in means between sexes were obtained.Heritability of the traits was estimated by paternal half-sib correlation. The estimates for carcass traits were moderately high and agree well with most other estimates reported in the literature.

SUMMARYCarcass yield and chemical composition of edible meat of fifteen fattened yearling rams and fifteen fattened yearling wethers of Sudan Desert sheep were studied. The animals studied were random samples from groups which had been fattened for 2 months on three different rations. They were about 14 months old at slaughter, and their weights at slaughter ranged from 25 to 52 kg. The average dressing percentage for rams and wethers was 53·0 and 52·2% respectively. Warm carcass weights were 20·22 kg for rams and 19·64 kg for wethers, and these carcasses lost 4·2 and 3·1% of their weight respectively, after 48 h storage in the cold room at 0°C. The bone content of carcasses of rams and wethers was 23·4 and 21·3% respectively. The longissimus dorsi ‘loin eye’ area at the 12th rib was 8·6 cm2 and 8·3 cm2 for rams and wethers. The proportions of wholesale cuts in ram and wether carcasses were comparable, whereas the proportions of slaughter by-products varied between the two ‘sexes’. Mean weight of kidney fat in wethers was 50% greater than in intact rams, but the mesenteric and caul fat was heavier in rams than in wethers.Ram carcasses had higher specific gravity than those of wether carcasses. Specific gravity was negatively correlated with fat content and positively correlated with protein, moisture and ash content of the edible meat of the carcass. The regression equations relating specific gravity to the major chemical components of meat had too high standard errors to be of predictive value in a practical sense.

Relationships between a number of split and internal carcass measurements and per cent yield of the carcass and its component cuts when trimmed in accordance with commercial standards were examined using a sample of 482 hog carcasses. Carcass length and weight were found to have low predictive value, accounting respectively for approximately 9 and 4% of the total variance in per cent yield of the trimmed lean cuts (ham, loin, picnic, and butt). Commercial grade explained approximately 27% of the variance in this trait and sex approximately 21%. The most useful predictors of per cent yield of lean cuts, and the proportion of total variance explained by each, were: per cent yield of trimmed loin, 83%; ratio of loin area to total back fat, 53%; total back fat, 54%; and per cent lean in the ham face, 43%. A regression equation combining total back fat, loin area, and per cent lean in the ham face explained 63%. Regression equations are provided and implications as regards commercial grading and carcass appraisal for progeny testing are discussed.

Data for 61,138 pig carcasses from 19 commercial packing plants across Canada were analyzed. These represented almost the complete Canadian kill of commercial pigs for one week. Barrow carcasses were fatter than those of gilts by an average of 0.66 cm total backfat (sum of measurements at the shoulder and loin). This difference was consistent at all weights with an almost parallel regression of total backfat on carcass weight for each sex (regression of 0.089 and 0.086 cm/kg for barrows and gilts, respectively). The three commercial grades of A, B and C divided carcasses into groups which differed in total backfat (averages of 7.33, 8.44 and 10.17 cm respectively) but which showed considerable variation in backfat within grades (standard deviation of 0.861, 0.999 and 0.947 cm respectively). Regional differences existed in carcass grades which were associated with differences in carcass weights. There was little to suggest that regional differences in carcass merit per se existed. Carcass weight had a large influence on commercial grade. As carcass weight increased from 61.4 kg to 68.1 kg, the percentage of grade A carcasses decreased from 42.8 to 34.5%. At 68.5 kg, however, the percentage of A carcasses averaged 59.7. This percentage decreased with increasing weight and averaged 46.4% at 77.2 kg. Only 4.7% of all carcasses were downgraded for reasons other than fat. The implications of these results are discussed.

Twenty-four sires, 168 dams, and 653 market pigs of several breeds were typed for up to 32 blood group factors to investigate possible relationships between blood group factors and economic traits. Least squares methods were used to study the effects of blood group factors on five measures of reproductive performance (numbers born, born dead, alive at birth, alive at 21 days, and alive at 56 days), four stages of growth (weight at birth, 21 days, 56 days, and 154 days), four carcass traits (length, total backfat, loin eye area, and lean cut yield), and on susceptibility to atrophic rhinitis. A greater frequency of low F-test probabilities than expected was observed for both growth and carcass traits. F-values for 10 of 107 factor-growth trait combinations (9.3%) and 16 of 104 factor-carcass trait combinations (15.4%) were significant (P

En la producción moderna de cerdos, la alimentación representa del 70 a 80% de los costos. En zonas tropicales que no tienen ventajas comparativas para producir cereales, pueden utilizar alternativas alimenticias como papa, yuca, malanga, camote, caña de azúcar, melaza y otros subproductos agro-industriales. El objetivo de este estudio fue evaluar el efecto de cuatro niveles de melaza en la dieta de cerdos en las etapas de crecimiento y engorde. El estudio se realizó entre enero y mayo de 2005 en la Escuela Agrícola Panamericana, Honduras. Se utilizaron cuatro grupos de 30 cerdos cada uno, con peso promedio de 27 kg en la etapa de crecimiento y de 48 kg en la etapa de engorde, los cerdos eran cruces de Landrace, Yorkshire, Duroc y cruce con verracos híbridos de la empresa PIC. Los tratamientos fueron 0, 10, 20 ó 30% de melaza en la dieta para ambas etapas. Se utilizó un Diseño Completamente al Azar, con cuatro tratamientos y tres repeticiones. Se realizó un Análisis de Varianza mediante el Modelo Lineal General (GLM), con una probabilidad menor a 0.05. Los cerdos que recibieron la dieta con 0% de melaza tuvieron una mayor ganancia de peso (781 g/cerdo/día) que los que recibieron melaza, no se encontraron diferencias entre los tratamientos en el consumo de alimento ni en el índice de conversión alimenticia en la etapa de crecimiento. En la etapa de engorde no se encontraron diferencias significativas (P> 0.05) para ninguna de las variables evaluadas. Es posible alimentar cerdos con dietas que contengan hasta un 30% de melaza sin alterar el rendimiento en canal, grasa dorsal ni área del lomo. Los costos de alimentación se pueden reducir hasta un 22% en dietas con 30% de melaza para la etapa de crecimiento y 24% en la etapa de engorde, sin embargo, el mayor margen sobre el costo de alimentación encontrado fue en dietas con 20%.Palabras clave: Área de lomo, desempeño animal, grasa dorsal, rendimiento de canal DOI: http://dx.doi.org/10.5377/ceiba.v47i1-2.441 Ceiba, 2006. Volumen 47(1-2):3-9

Sixty-six male pigs were allotted at random at birth to six castration treatments: partial castration at 6 and 26 days according to the Baiburtcjan method and complete castration at 6, 26, and 76 days and at 68 kg liveweight. No meaningful treatment differences were detected in growth rate or in carcass measurements (length, backfat thickness, loin eye area, percent lean in the ham face and percent ham of the side). The overall environment of the experiment limited growth rate of normal castrates to approximately 0.45 kg per day. The possibility of the environment dampening the expression of treatment effects cannot be precluded. The method of partial castration used was difficult to perform and more time-consuming than complete castration. It reduced testicular development bur did not eliminate it. Many of the partial castrates molested pen mates and sonic mated with gilts. Of 22 carcasses from partial castrates, 15 were detected as having odor.

SUMMARY The effects of ethylenediamiuetetraacetate (EDTA), pyrophosphate, and elevated pH on rehydratiou capacity and texture of freeze-dried meat were studied. Samples of pork loin were injected with solutions of EDTA and pyrophosphate in a cont. of approx. 10mM per 1000 g meat. After injection, the samples were frozen and freeze-dried. The treated samples had improved rehydratiou capacities and texture as measured with a Warner-Bratzler shear press. The main effect of EDTA appeared to he better penetration of water into the dried meat structure, whereas the effect of pyrophosphate appeared to he mainly swelling of the already wetted areas. These observations were substantiated by an experiment in which samples were frozen but not dehydrated. In this case, only pyrophosphate improved water-binding capacity. Application of EDTA in the rehydratiug solution did not improve the rehydration capacity of the freeze-dried samples. The average pH of the meat was raised approx. 1 unit through injection of NaOH solution before drying. This treatment did not appreciably improve hydration capacity or texture. Aging the meat before treatment with EDTA and NaOH did not improve the results. EDTA exhibited the same effects on beef as on pork.

Effects of castration on growth, wool production, carcass characteristics, and meat quality in sheep were investigated.The experiment included two flocks (similar in their effect on pre-weaning performance, but representing high and low planes of nutrition after weaning), two years, and two slaughter ages. Rams weighed approximately 5 % more thanwethers at weaning, and 15 % and 23 % more as yearlings on the low- and high planes of nutrition respectively. Differences in favour of rams in terms of skeletal and muscle size and wool production were also greater on the higher plane of nutrition. Carcass weight was approximately 4%, 8% and 19% higher for rams among lambs, low plane and high plane yearlings, respectively. Proportion of carcass weight in the forequarters was 0·5 %, 1·1 % and 2·3 % higher for rams in these three groups. Rams had less kidney fat and the same percentage of the carcass weight in loin and trimmed leg as wethers in all groups.Carcass grade and eating quality as evaluated by a taste panel did not differ between ram and wether lambs. Among the lighter yearling group, meat from the loin of ram carcasses was less tender. Quality was appreciably lower for rams in the heavier yearling group. Meat from ram carcasses had 1 to 2% higher cooking loss than that from wethers.

Two experiments, involving 144 individually-fed pigs, were conducted to determine the effects of fish visceral flour in growing and finishing rations on the performance and carcass characteristics of bacon pigs.The most rapid average daily gains in this study were obtained from pigs fed mixtures of fish visceral flour and soybean meal. Pigs fed fish visceral flour as the only source of supplementary protein made slower gains in both experiments than those fed other rations.Pigs fed high energy rations made more rapid gains in the finishing period and more efficient gains in the finishing and total feeding periods than those fed the control rations.Level of fish visceral flour in the ration had no significant effect on carcass scores and grades. However, area of loin muscle decreased with increasing levels of fish visceral flour. High energy rations had an adverse effect on carcass measurements.

Three trials, with a total of 20 pigs on each of eight treatments, were conducted to determine the effect, on carcass quality of Yorkshire pigs, of self-feeding rations of low, medium, standard, and high protein content, with and without chlortetracycline (aureomycin), from weaning to market weight. The approximate protein levels were 13, 15, 17, and 19 per cent from weaning to 70 lb.; 12, 13.5, 14.5, and 15.5 per cent from 70 to 130 lb.; and 11, 12, 12.5, and 13 per cent from 130 to 200 lb.Aureomycin had no significant effect on length of carcass, or on the area of the eye of lean, at any of the four levels of protein tested. Aureomycin significantly increased the depth of backfat, but not shoulder or loin fat, at all protein levels. With the type of pigs used this increase did not have any adverse effect on grades.Protein level had no significant effect on length of carcass, depth of shoulder fat, or depth of backfat. As protein level increased, increases in the area of the eye of lean occurred.

SUMMARY— The tenderness of lamb loin is affected greatly by the time-temperature pattern imposed on the dressed carcazs during the onset of rigor mortis. Very significant toughness develops in the longissimus dorsi muscles of carcasses exposed to low temperatures within about 16 hr of slaughter. This “processing toughness” is shown to be unrelated to the lack of aging. It appears to be due to muscle fiber shortening, earlier demonstrated to be responsible for massive toughening in excised muscles. Both cold shortening and thaw shortening are capable of toughness production, the latter type becoming prominent when meat, previously frozen before rigor completion, is cooked without a preliminary thawing.

SummaryResults are reported of an experiment with fattening pigs, made under commercial conditions, on the effect of adding formalin to liquid skim-milk, to delay souring, on the nutritive value of the milk given either in restricted or in unrestricted quantities.There were four treatments: (i) Meal, fed to a scale based on live weight, plus sour skim-milk restricted to a maximum of 5¼ pints per pig per day. (ii) As (i) except that milk kept sweet by the addition of 0·15% formalin shortly after separation, was fed. (iii) Daily allowance of 2 lb meal/pig fed throughout the fattening period plus an unrestricted supply of sour skim-milk. (iv) As (iii) except that milk kept sweet by the addition of 0·15% formalin shortly after separation, was fed.There were five pens of nine group-fed pigs on each treatment, involving a total of 180 pigs. The pigs were on experiment from about 9 weeks of age to bacon weight. Comprehensive carcass measurements were made on all the pigs, and bacon-tasting tests were made on samples of both green and smoked bacon from a number of the carcasses.There were no significant differences between any of the four treatments in rate of growth or overall efficiency of food utilization.Pigs given formalin-treated milk had a significantly thinner layer of back fat over the loin than those given sour milk. Although the difference was relatively small, it was apparent whether the milk was fed in restricted amounts or ad lib. and was reflected in the commercial grading results. There were no significant differences between treatments in dressing percentage, carcass length, shoulder back fat thickness, belly thickness or size of eye muscle.No taint or off-flavour was detected in samples of green or smoked bacon from pigs fed milk to which 0·15% formalin had been added.The feeding of liquid skim-milk in unrestricted quantities is discussed in relation to the comparative prices of meal and skim-milk.The importance of adding the formalin to the skim-milk as soon as possible after separation, particularly during warm weather, is stressed in order that souring might be delayed for at least 1 week.

1. The effect, on the concentration of volatile fatty acids (VFA) in the rumen, of increasing the frequency of feeding from twice daily to four or six times daily was investigated in sheep given isocaloric rations containing VFA salts. In a second experiment isocaloric rations containing acetate and propionate were given to groups of lambs in two or six equal feeds daily. The efficiency with which the lambs utilized the VFA salts was measured as gain in live weight, empty body weight and carcass weight and was compared to that of lambs receiving only the basal ration. The composition of the carcasses was estimated from that of the loin. 2. Increasing the frequency of feeding from twice daily to four or six times daily significantly reduced the marked changes in rumen VFA composition associated with giving rations containing VFA salts twice daily. In lambs receiving acetate and propionate, final live weight, empty body weight and carcass weight were significantly greater than in lambs receiving only the basal ration (P < 0.001). The combustible energy from added VFA was apparently utilized more efficiently than the calculated metabolizable energy of the basal rations given above maintenance level, and there was no difference between the utilization of acetate and propionate. 3. There were no differences approaching significance between feeding twice daily and six times daily either between groups of lambs receiving only the basal diet or between those given the diets supplemented with VFA salts. Nor were there any interactions between VFA and frequency of feeding. 4. It is postulated that in ruminants the effect of frequency of feeding depends on the environment and level of feeding.

The elastin content of various muscles of beef animals has been measured by a technique designed to remove the last traces of collagen and myofibrillar proteins. Amino acid analysis of the elastin prepared in this way is almost identical with that of purified elastin from ox ligamentum nuchae. In particular, the hydroxyproline values of each are less than 2% of the dry weight. Most of the choice cuts of meat from the hindquarter and loin contain less than 0.2% elastin on the dry weight basis, i.e. less than 5% of the total connective tissue. The M. semitendinosus is the chief exception found. It contains about 2% dry fat free solids (DFFS), i.e. about 40% of the connective tissue. In the forequarter, the latissimus dorsi is the only muscle which contains as much elastin as the semitendinosus, i.e. about 2.0% DFFS. Muscles of intermediate elastin content are the trapezius, rhomboideus and pectoralis superficilias (about 0.4 to 0.8% DFFS). The muscle of the skin, panniculus, has a somewhat higher content of about 1.2% DFFS. Elastin appears to contribute to the toughness of a cooked muscle to about the same extent as denatured collagen. Thus the semitendinosus and biceps femoris have similar total connective tissue contents, and are about equally tough, but the former contains 15 times more elastin than the latter.

SUMMARYTwo trials were carried out to investigate the effects of increasing calorie: protein (C:P) ratios of high iso-nitrogenous diets on the performance characteristics, nutrient digestibility, carcass quality and organ weights of 67 growing pigs of the Yorkshire and Landrace breeds, reared in a tropical environment on concrete-floored pens from 9 to 56-8 kg live weight before slaughtering and grading. The dietary protein content was approximately 24 % of dry matter in all cases, and the C:P ratios ranged from 153 to 184 kcal digestible energy/g in both trials. Results showed no consistently significant differences in gain and feed intake due to increasing C:P ratio, but feed conversion ratios consistently improved with increasing C:P ratio. Digestible energy consumed per kg of body weight gained also increased with increasing C:P ratio. The nutrient digestion coefficients did not appear to be significantly affected by the C:P ratio. With respect to carcass quality measurements, there were nonsignificant differences in dressing percentage and average backfat measurements, but significant differences in percentage trimmed fat with increase in C:P ratio. The carcass length, loin eye area, and percentage lean cuts decreased as the C:P ratios increased, the last two showing significant differences only in the second trial. The organ weights showed no significant differences due to increases in C:P ratio.

1. The accurate measurement of the amount of bone, muscle and fat in the bodies of meat animals is of considerable importance in all technical studies relating to carcass quality. Chemical analysis and laboratory dissection of complete animals are associated with disadvantages which preclude their extensive use. Material derived from nutritional experiments has provided the opportunity for statistical investigation of the possibility of using sample joints and carcass measurements as indices of the composition of bacon pigs of 200 lb. live weight. The extent and nature of the variation in the composition of the pigs concerned adds to the significance of the results obtained.2. The total weight of bone, muscle and fat in the bacon-pig carcass can be estimated with a high degree of accuracy from the respective weights of these tissues in either the loin or the leg. The combination of these two joints provide even higher correlations in each case than either one alone. In all cases the correlation coefficients approach unity and are strongly significant at the 1% point. For the combined joints the values ofrfor bone, muscle and fat respectively are +0·9444, + 0·9765 and +0·9750. Regression functions have been developed for the purpose of estimating carcass composition from these joints.

Summary The specific gravities (S.G.) of 58 Romney ewe mutton carcasses have been correlated with total carcass fat content and regression equations computed. A curvilinear regression of the form: Y (per cent fat in the carcass) = 8371.3 S.G. — 4382.9 S.G.2 — 3932.9 was fitted to the data. Correlation coefficients and regression equations for S.G. of the 9–10–11 rib cut, loin, and leg and state of fatness of these joints are presented. Some factors affecting the accuracy of determining S.G. and the predictive value of S.G. as an index of fat content of carcasses and certain joints are considered.

Data over two years on a total of 149 Shorthorn bulls from a closed herd under direct selection for yearling weight were used to examine line differences in carcass yield and quality and to evaluate relationships between live performance and carcass yield and quality. No significant differences [Formula: see text] in performance or carcass data between control and selected lines were apparent in 1967. However, in 1968 bulls from the selected line were heavier at slaughter (470.5 kg vs. 441.8 kg), their carcasses contained more kidney fat (9.14 kg vs. 8.46 kg), and they had larger loin eye area but smaller weight-adjusted loin eye area. Rate of gain was superior for the selected line whether examined as live-weight, carcass weight, trimmed primal cut weight or lean weight per day of age. There were no significant differences between lines for percent fat, lean or bone in primal cuts, or for rib fat thickness, percent trimmed prime cuts, percent seam fat, muscle/bone and hind/front ratios, or for chemical composition or tenderness evaluations of the longissimus dorsi. Averaged over the two years and at the same averaged slaughter weights (418 days), selected-line bulls produced a significantly greater quantity of total carcass, of trimmed primal cuts and of total lean than did the control-line bulls; selection for yearling weight appeared to have been effective in increasing rate of lean growth. Phenotypic correlations indicated that liveweight/day of age was more highly related to variation in lean growth rate than growth rate of fat. From 20 to 60% of the variation in wholesale cut weights was associated with differences in rate of gain. Distribution of the gains was little influenced by rate of gain. Tenderness evaluations were not related to live performance.

1. Twenty Southdown-Romney wether lamb carcasses of a mean hot carcass weight of 39·2 lb. (range 31·2–43·8 lb.) were frozen. Each frozen carcass was divided down the back-bone to give two sides and each side was divided into four parts: leg, loin, 9–10–11 rib cut, and fore. A method of obtaining samples from the parts and from the sides is described. The samples were analysed for water, fat (uncorrected), and residue (uncorrected). The dried residue was analysed to give an ash percentage and a Soxhlet correction factor so that total fat (ether-extract), protein (dried fat-free, ash-free residue), and ash were determined.2. The weights of the two sides of the twenty carcasses were similar, although the loins of the left sides were highly significantly heavier than those from the right sides and the right fores were highly significantly heavier than the left fores.3. The mean percentage composition of the two sides of the carcasses studied were similar. Likewise each of the four parts showed close similarity between sides except for the residue and protein percentage of the loin in which the left sides had significantly more protein percentage than the right sides. In all the uncorrected chemical components a significant side × carcass interaction was found.4. An analysis of the sampling errors showed that the variance of a treatment mean was decreased only slightly by increasing the number of samples per side or by sampling both sides instead of one. Any substantial increase in precision can be achieved only by increasing the number of carcasses per group.

SUMMARY— Boneless, trimmed steaks (U. S. Good) from the longissimns dorsi muscle (loin) and semimembranosus muscle (top-round) and conventionally cut loin steaks were removed 8 days post-mortem, quick-frozen and stored at −18°C to −23°C for three storage periods, 0, 6, and 9 months. Steaks were sampled at each storage period and cooked to an internal temperature of 70°C in a microwave oven and electric range. Quality was evaluated by chemical tests, sensory evaluations and cooking loss data. Storage up to 6 months had little effect on loin steaks with the exception of TBA values, but significant changes occurred between 6 and 9 months. Loin steaks had increased cooking losses and decreased juiciness scores, percent moisture, and juice content. TBA values increased with each storage period. Top-round steaks at the 9-month period showed a decrease in collagen content and juiciness and flavor scores, and an increase in TBA values. Storage up to 9 months did not influence tenderness in either muscle. Conventionally broiled loin steaks had higher palatability scores, cooking losses, percent moisture, percent total proteins, and lower percent total lipids than did microwave cooked loin steaks. Electronically cooked top-round steaks had higher total cooking losses and percent total proteins and lower collagen values than did conventionally roasted top-round steaks. The qualities of boneless loin steaks did not differ significantly from those of conventionally cut loin steaks when compared at each storage period.

Analysis of performance data from 209 barrows and 222 gilts, representing 135 gilt litters, indicated an important inverse relationship between litter size at birth and weaning and individual pig weights at both ages. Differences in litter size at weaning had no measurable influence on the post-weaning traits of average daily gain during the weight-constant growth period of 50 to 195 ± 3 pounds or on the carcass traits of length and loin area. There was reasonably consistent evidence of a small effect on total back fat, with females from small litters producing a greater amount of fat than expected in relation to their contemporary test barrows. These relationships were confirmed by analysis of a further sample of 149 barrows and 147 gilts from 82 litters. The significance of these findings in relation to R.O.P. testing is discussed briefly.

The eating qualities of pork from the longissimus dorsi muscles of pigs showing a wide variation in fatness (10-40 mm, back fat thickness) were assessed by taste panel after either the excised muscle had been grilled or a complete loin joint had been roasted. The average panel scores for texture and juiciness covered a wide range but were not consistently related to fatness. Although meat from fatter pigs tended to be judged more tender in direct comparisons, overall the results did not support the contention that fatness in the carcass is associated with tenderness in the lean meat.

Carcass data from 123 pigs slaughtered at either 120 lb., 200 lb. or 260 lb. live-weight have been analysed to study the relative value of four sample joints in predicting tissue composition in the carcass.Percentage fat, muscle or bone in all joints was highly correlated (PSignificance tests of the a and b constants in regression equations relating percentage fat, bone and muscle in the joint to that in the carcass showed that only with the rib joint was it legitimate to combine the data from each slaughter weight into ‘overall’ equations.As pooling the data for the combined loin and ham joint had little effect on the magnitude of the residual standard errors, overall equations relating tissue composition of that joint to the whole are also given. The accuracy of prediction, however, was lower than that obtained with the rib joint.Application of the pooled regression equations relating carcass and rib joint composition to independent data, obtained by identical techniques, gave promising results.

One hundred pigs were used in two experiments to determine the nutritive value of a purified source of cellulose (solka-floc) and its effect on body composition and iodine number of the loin fat. In each experiment one group of pigs received a basal ration ad libitum while levels of 10 and 40 per cent solka floe were added to the basal ration of two groups at 62 and 162 pounds liveweight, respectively. The pigs given solka-floc were fed ad libitum and the amounts of basal ration consumed were pair-fed to two respective control groups. There was a significant decrease (P

Summary The use of the leg and the loin as sample joints for estimating the carcass composition in terms of fat, muscle, and bone of 120 New Zealand lamb and mutton carcasses is discussed. In all cases the correlations between the dissectible components of these two joints and the same components of the whole carcass were highly significant. The correlation coefficients show that the combination of a leg and loin are better indices of carcass composition than either joint alone. Regression equations are presented for estimating carcass composition from the weights of the components of the leg and the loin. The use of the neck, thorax, shoulder, and pelvis as sample joints is also considered.

SUMMARYRelationships between specific gravity and carcass tissue were studied in 83 purebred Clun Forest lambs slaughtered at approximately 80 lb. liveweight and ranging in carcass weight from 29 to 42 lb. Carcass specific gravity accounted for 86·1% and 78·1% of the respective variances in carcass fat percentage and muscle percentage. Specific gravity determinations on a single joint were also highly correlated with the carcass tissues. Correlation coefficients between loin specific gravity and carcass fat and muscle were −0·89 and 0·82 respectively; corresponding figures for best-neck specific gravity were −0·86 with carcass fat percentage, and 0·76 with carcass muscle percentage. In partial correlation analyses, muscle/bone ratio failed to have a significant effect on these relationships. The usefulness of estimates of carcass composition based on specific gravity determinations is discussed in relation to the maximum probable errors associated with predicted values and with reference to the accuracy of these estimates under different experimental conditions. The magnitude of the confidence limits (P = 0·05) on individual predictions varied from ±2·98% to ±3·48% for fat and muscle respectively and for group (n= 12) predictions, from ±0·88% to ±1·01% respectively. This suggests that little confidence can be placed in specific gravity determinations as a reflection of real individual differences or small treatment differences.

1. By establishing the relationship between linear carcass measurements and the quantitative composition of the carcass in terms of bone, muscle and fat, we have provided a scientific basis for the use of many measurements hitherto only presumed to provide an index to carcass quality.2. External carcass measurements are correlated with weight of the skeleton. The most useful for this purpose are length of tibia + tarsus and length of the fore-cannon.3. As indices of muscle, external measures are only of indirect value. Thus, both F – T and G/F × 100 are strongly correlated with weight of muscle as a percentage of skeletal weight.4. Similarly, F provides an index of fat, being negatively correlated with fat as a percentage of bone.5. For muscle and fat internal measures permit a more precise estimate to be made. A + B is the best index of the former while C + J + Y provide the most accurate estimate of the weight of fat.6. Still better indices for muscle and fat are provided by suitable combinations of external and internal measurements. Thus L/10 + A + B is very highly correlated with the weight of muscle, and L/10 × (C + J + Y) is the best index of fat in the hoggets. For bone, a most efficient single index is shown to be the weight of the fore-cannon bone.7. The weight of the skeleton can be estimated with a high degree of accuracy from the weight of the bones in either one leg or loin. Both these joints combined, however, provide a still better estimate.8. The muscle in one leg or loin + leg provides an excellent index of the weight of muscle in the whole carcass.9. The fat in one leg, loin, or both these joints combined provides a good index of the weight of the total fat in the carcass. Both joints combined give the most precise measure.10. The value of certain measurements which are not necessarily associated with the quantity of the major tissues of the carcass, but which nevertheless have important qualitative significance, is emphasized.

Data on carcasses of 352 Large White baconers by 44 boars were taken from reports of Progeny Testing Stations to estimate the heritability of chemical fat in the loin muscle and of fatty tissue content in the carcass, and their phenotypic and genetic correlations.The heritability of the chemical fat content in the loin muscle was found to be 0·50, that of the fatty tissue content in the carcass 0·69. The genetic correlation between the characteristics under study seems to be very low (rA = 0·11), and their phenotypic correlation, though significant statistically, was also found to be low (about 0·2).

1. In two experiments with growing and fattening lambs sodium and calcium salts of volatile fatty acids (VFA) were added to a basal diet of hay and concentrate. In Expt I the lambs were approaching maturity, and the utilization of salts of acetic, propionic and butyric acids was studied. In Expt 2 the animals were younger; the experimental groups received acetate or propionate, and half of them were implanted with hexoestrol. The chemical composition of the carcass was assessed with the loin as a representative joint. The influence of the VFA salts on the digestibility of the basal ration was also investigated. 2. In both experiments the lambs receiving supplements of VFA salts grew faster, and their empty body weights and carcass weights were significantly greater than in lambs receiving the basal diet. 3. The energy derived from acetate and propionate was utilized more efficiently to promote carcass gains than the calculated metabolizable energy above maintenance of the basal ration. There were no differences in the utilization of energy from the different VFA, except in Expt I in which butyrate was utilized somewhat less efficiently than acetate and propionate. 4. Hexoes-trol implantation resulted in faster growth, and highly significantly greater empty body weights and carcass weights. There was no evidence of an interaction between the VFA and hexoestrol treatments. 5. There were no differences between the VFA treatments in the composition of the carcass gains as judged by the composition of the loins, except in Expt I in which lambs receiving acetate tended to be the fattest. The coefficient of variation in loin fat percentages was large in both experiments, but, in Expt I in which both ewe and wether lambs were used, the coefficient of variation among the wether lambs was four times that of the ewe lambs. 6. Additions of VFA salts to the diet resulted in a significant increase in the excretion of ash.

The body fat of three 50-kg pigs was labelled with 14C by feeding them 14C-palmitic acid. When later given a single, oral dose of 3.0 g of theophylline, these pigs expired six times as much 14CO2 during the subsequent 12 hr compared with control periods when no theophylline was given. Similarly, in the 12- to 24-hr interval after theophylline was administered, 29% more 14CO2 and 22% more CO2 was expired. In an experiment with 12 pairs of pigs, those fed theophylline from weaning until market weight had a 13% increase (P

Ninety-six Yorkshire pigs, reared during the growing period on high energy–high protein rations, were used in a 2 × 2 factorial feeding experiment to compare two levels of protein at two levels of energy in self-fed finishing rations. Pigs fed a high energy ration gained 0.34 lb more per day, consumed less feed, had more loin and back fat, lower Record of Performance (R.O.P.) scores, and received lower commercial grades than those fed the lower energy ration. The level of protein fed did not affect significantly, rate of gain, feed utilization, or carcass quality. An interaction existed between protein and energy whereby the adverse effects on carcass quality of the high level of energy were modified by the high level of protein with the result that average loin area was increased and a higher R.O.P. score and a higher percentage of grade A carcasses was obtained.

SUMMARY: A completely randomized design was followed to evaluate 48 roasts posterior third of the loin) from 12 Duroc and 12 Poland China barrows. Antemortem treatment of pigs produced “normal”, pale-soft-exudative (PSE) and dark-firm-dry (DFD) longissimus dorsi (LD) muscle. Meat was roasted at 350°F to an internal temperature of 167°F and evaluated by organoleptic and selected objective measurements. There was no significant organoleptic preference for one type (“normal”, PSE, DFD) of LD. Also, differences among types of muscle were not significant for roasting time, volume of press fluid or total moisture (press method); whereas roasting losses, total moisture (Brabender) and pH of LD were affected significantly by type of muscle. In general, there were significant (P < 0.05) differences between PSE and DFD muscle, and between “normal” and DFD muscle. DFD muscle exhibited the smallest roasting loss and greatest total moisture, whereas PSE muscle had the greatest roasting loss and least total moisture. DFD muscle rated highest in pH and lowest in Warner-Bratzler shear value. LD from Durocs was more tender (P < 0.05), had a higher (P < 0.05) pH, and contained less (P < 0.01) total moisture (Brabender) than LD from Poland Chinas. Cooking losses were greater (P < 0.05) for roasts from Durocs than for roasts from Poland Chinas.

An experiment was carried out to evaluate the importance of genotype-environment interactions in Canadian Yorkshire swine. Two males and two females from each of four litters by each of four sires were randomly allotted to two feeding and management treatments. One male and one female from each litter were self-fed A.R. feed mixtures in a piggery and the other male and female were self-fed the same feeds on pasture. Weights were taken at 56 and 140 days of age and at 190-200 lb. live weight. Carcass measurements were taken at slaughter.Rate of gain from 56 to 140 days for pasture-fed pigs was significantly lower (P =

Factors associated with differences in carcass conformation were studied in three experiments involving 85 pairs of lambs, half of which had been selected as having blocky conformation and half leggy conformation. Pairs of carcasses were matched for carcass weight and age at slaughter. The blocky carcasses contained more fat and less red meat and bone than the leggy carcasses. They also had a higher proportion of the fatter cuts (loin, ribs, and flap) and a lower proportion of the leaner cuts such as the leg. A taste panel found the palatability characteristics of leg meat from both types of carcasses acceptable and did not differentiate between them. The differences in conformation strongly influenced the export grading of the carcasses, the blocky carcasses grading predominantly Prime Down Cross and the leggy carcasses mainly Prime Crossbred and Y. Southdown sires produced the blockiest carcasses and the other breeds studied produced the leggiest carcasses. Within-breed variation was also noted...

The influence of high (HE) and low (LE) digestible energy diets fed for two 1-hr periods per day on the performance of Duroc × Yorkshire, Hampshire × Yorkshire, or Yorkshire × Yorkshire pigs marketed at 68, 91 or 114 kg liveweight was studied. Under the feeding system employed, daily feed intake averaged 2.01 kg and did not differ between dietary groups. The HE diet containing 3652 kcal DE/kg improved (P

SUMMARYInterrelationships between carcass measurements were studied in 83 purebred Clun Forest lambs slaughtered at approximately 80 lb. live-weight and ranging in carcass weight from 29 to 42 lb. Individual carcass measurements did not have a worthwhile predictive value; apart from loin (C) and rib (J) fat depths none of 12 external or internal carcass measurements showed a correlation with carcass composition greater than r = 0·70. Similarly, none of 9 offal measurements recorded had a worthwhile predictive value. In multiple regression certain combinations of these measurements accounted for as much as 77% of the variation in carcass fat, 64% in carcass muscle and 64 % in carcass bone.The predictive efficiency of sample joint composition, specific gravity determinations and carcass measurements were evaluated in terms of the increased error variance using predicted values and the effect of this increase on sample size in treatment comparisons. Generally the results indicated that increasing treatment group size by relatively few animals is sufficient to absorb the additional error variance arising from the use of predicted values. This is particularly true where treatment differences of the order of one standard deviation exist and where part-carcass dissection values are used.

Procedures have been suggested for the evaluation of the resistance of spores of Clostridium botulinum in food products subjected to ionizing radiation and have been illustrated by representative data. The occurrence of nontoxic spoilage yielding either strongly toxic or questionably toxic cultures has been noted. Although a mixture of strains, 3 Type A and 2 Type B, was used as inoculum, all survivors produced Type A toxin; and it is suggested that the determination of radiation resistance with a suspension representing a mixture of strains is inadvisable. Approximately the same resistance of the inoculum was found in chicken parts, steak, and whole kernel corn; survival at 2.8; no survival at 3.0 megarad; radiation D value, 0.33 to 0.35 megarad. In pork loin, resistance appeared slightiy lower but on the borderline of significance. Resistance of the suspension appeared definitely lower in green beans, based upon a comparison of D values. (Public Health Eng. Abstr. 40 (1960) Dec.)