Carcass Side Weight Research Articles

GROWTH PERFORMANCE, SLAUGHTER AND CARCASS COMPOSITIONAL TRAITS IN RABBITS OF A LOCAL STRAIN AND NEW ZEALAND WHITE BREED RAISED IN BURUNDI

A total of 77 males rabbits represented the Local rabbits (L) of Burundi and the New Zealand White (NZW) breed were used to evaluate the genetic differences among the two genotypes in live performance, slaughter and carcass compositional traits and to show the possibility of integrating the Local rabbits with the NZW breed in the Burundian rabbit industry for meat production. The rabbits were slaughtered al an average age of 12 weeks. Results showed that from 3 to 12 weeks of age the NZW breed produced significantly heavier animals and grew significantly faster than those of the Local strain at all ages considered in the study (1948 vs 982 g at 12 weeks). Local rabbits had higher proportions of non carcass components (except for pelt), bone in the carcass and carcass side weight occurring in fore limb, loin and hind limb and lower dressing percentage (44,7% vs 46,8%) and carcass lean to bone ratio and less lean in the carcass (80,4% vs 86,6%), and lower proportion of abdominal wall in the carcass than those of NZW rabbits. Results showed also the better distribution of carcass lean weight over the side cuts and the lower degree of carcass leanness of the Local rabbits compared to the NZW ral:Ibits. lt seems more beneficia! for the rabbit producers in Burundi to use the NZW breed in a crossbreeding program with the Local strain for rabbit meat production.

Polymorphisms in coding and regulatory regions of the porcineMYF6 andMYOG genes and expression of theMYF6 gene inm. longissimus dorsi versus productive traits in pigs

MYOG and MYF6 belong to the MyoD gene family. They code for the bHLH transcription factors playing a key role in later stages of myogenesis: differentiation and maturation of myotubes. Three SNPs in porcine MYF6 and two in porcine MYOG were analysed in order to establish associations with chosen carcass quality and growth rate traits in Polish Landrace, Polish Large White and line 990 sows. No statistically significant effect of SNP in the promoter region of the MYF6 gene on its expression measured on mRNA level was found. Associations between the genotype at the MYF6 locus and carcass quality traits appeared to be breed-dependent. The C allele in the case of SNP in the promoter region and GC haplotype in exon 1 were advantageous for right carcass side weight in Polish Landrace sows and disadvantageous for this trait in Polish Large White sows. These gene variants were also the most advantageous for loin and ham weight in sows of line 990. The mutation in exon 1 of the MYOG gene had no statistically significant association with carcass quality traits and the mutation in the 3'-flanking region had the breed-dependent effect as well. These results suggest that SNPs analysed in this study are not causative mutations, but can be considered as markers of some other, still unrevealed genetic polymorphism that influences the physiological processes and phenotypic traits considered in this study.

Carcass dissection and commercial meat yield in Piemontese and Belgian Blue double-muscled young bulls

To study the differences in meat yield in hypertrophied cattle, a commercial dissection trial was carried out on 48 carcasses obtained from 24 Piemontese (P: 12 reared with a restricted feeding, P-R, and 12 fed ad libitum, P-L), and 24 Belgian Blue (B: 12 reared with a restricted feeding, BB-R, and 12 fed ad libitum, BB-L) young bulls. The animals were reared under the same environmental condition and slaughtered at the same age and fattening degree. During commercial dissection, the weights of the retail cuts were recorded. Three fore-quarter meat cuts were heavier in P than in BB, while nine meat cuts (two from fore-quarter and seven from hind-quarter), hind-quarter meat and prime quality meat were heavier in BB than in P. Fat weight was higher in BB than in P, whereas meat production as a percentage of carcass side weight was higher in P than in BB. Only one hind-quarter meat cut was heavier in the ad libitum (L) than in the restricted (R) group, whereas meat yield was higher in R than in L. In comparing the meat yield in carcass sides of P-R, P-L, BB-R and BB-L fed young bulls, four meat cuts (one from fore-quarter and three from hind-quarter), hind-quarter, prime quality and 3rd quality meat were heavier in BB-L ( P ≤ 0.05), while one shoulder cut and fore-quarter were heavier in P-R group.

A comparison of Friesian-Holstein, Piemontese×Friesian-Holstein and Romagnola×Friesian-Holstein steers for beef production and carcass traits

Recently the Italian Piemontese and Romagnola beef breeds have been imported into Ireland. The objective of this study was to evaluate the progeny of these breeds from Friesian-Holstein dairy cows for beef production. A total of 120 spring-born steers comprised of 40 Friesian-Holsteins (FR), 40 Piemontese×Friesian-Holsteins (PM) and 40 Romagnola×Friesians-Holsteins (RO), born in 2 consecutive years, were reared from calfhood to slaughter at ∼2 years of age. Calves were artificially reared indoors and spent their first summer at pasture towards the end of which they were castrated. They were housed during the first winter and subsequently spent their second summer at pasture. At the start of the second winter they were assigned to a 3 (FR, PM, RO breed types)×2 (low and high feeding levels)×2 (short and extended finishing periods) factorial experiment. The low (L) and high (H) feeding levels were 3 and 6 kg concentrates per head daily, respectively, with grass silage ad libitum. The short (S) and extended (E) finishing periods were 124 and 207 days, respectively. After slaughter, the pistola hind quarter was separated into subcutaneous and intermuscular fats, bone and muscle. For the breed types as listed, mean values for carcass weight per day from arrival, kill-out proportion, carcass conformation score and carcass fat score were 434, 435, and 453 (S.E.D. 7.6) g, 519, 547 and 538 (S.E.D. 3.7) g/kg, 2.1, 2.9 and 2.9 (S.E.D. 0.12), and 4.0, 3.4 and 3.8 (S.E.D. 0.11), respectively. For FR, PM and RO, pistola weight as a proportion of carcass side weight was 447, 462, and 466 (S.E.D. 2.5) g/kg, pistola muscle proportion was 642, 716 and 687 (S.E.D. 4.1) g/kg, and pistola fat proportion was 165, 115 and 137 (S.E.D. 4.0) g/kg, respectively. Compared with L, the H feeding level increased carcass weight and improved carcass conformation but otherwise had few effects on carcass traits. Compared with S, the E finishing period increased carcass weight and all measures of carcass fatness. Allometric growth coefficients relative to carcass side weight for the hind quarter, the distal pelvic limb, the lumbar joint and the ribs joint were all <1.0, while the fore quarter and the proximal pelvic limb had coefficients >1.0. It is concluded that the Piemontese and Romagnola beef breeds are suitable for crossing on Friesian-Holstein dairy cows and the progeny are suited to Irish steer beef production systems. Productivity and carcass merit of these beef crosses are superior to those of Friesian-Holsteins. While live and carcass growth rates were higher for RO than PM, both had similar estimated muscle growth rates.

Prediction of swine carcass composition by total body electrical conductivity (TOBEC).

An experiment was conducted to determine prediction equations that used readings for total body electrical conductivity (TOBEC) in the model for estimation of total fat-free lean and total fat weight in the pork carcass. Ultrasound measurements of live hogs were used to select 32 gilts that represented a range in weight, muscling, and fatness. The TOBEC readings were recorded on warm carcass sides, chilled carcass sides, and the untrimmed ham from the left carcass side. Physical dissection and chemical analyses determined fat-free lean and fat weight of the carcass. All of the ham tissues were analyzed separately from the remainder of the carcass tissues to incorporate ham measurements for prediction of total fat-free lean and total fat weight in the entire carcass. Prediction equations were developed using stepwise regression procedures. An equation that used a warm carcass TOBEC reading in the model was determined to be the best warm TOBEC equation (R2 = 0.91; root mean square error = 0.81). A three-variable equation that used chilled carcass TOBEC reading, chilled carcass temperature, and carcass length in the model was determined to be the best chilled TOBEC equation (R2 = 0.93; root mean square error = 0.73). A four-variable equation that included chilled carcass side weight, untrimmed ham TOBEC reading, ham temperature, and fat thickness beneath the butt face of the ham in the model was determined to be the best equation overall (R2 = 0.95; root mean square error = 0.65). The TOBEC and the fat-free lean weight of the ham are excellent predictors of total carcass fat-free lean weight.

Growth, feed conversion efficiency and carcass composition of Arabian fat-tailed lambs fed diets with different proportions of a cardboard-based protein-enriched fermented feed

Twenty fat-tailed ram lambs of the Naeemi breed in Kuwait were offered four diets (5 lambs/diet) containing cardboard-based protein-enriched fermented feed (PEFF) and concentrates in ratios of 0 : 100 (control), 25 : 75 (PEFF25), 50 : 50 (PEFF50) and 75 : 25 (PEFF75) together with 200 g lucerne hay in order to determine the ability of PEFF to replace cereals in the diet. The PEFF was produced by treating cardboard boxes with Phanerochaete chrysosporium and Pleurotus ostreatus fungi which increased the crude protein (CP) content of the cardboard from 7 to 96 g/kg dry matter (DM). The average CP concentration of the diets fed was 162 g/kg. Average daily feed intake (ADFI), average dry matter intake (DMI), average daily gain (ADG) and feed conversion (i.e., FC = kg feed/kg gain), dressing percentage, carcass side weight (half-carcass), and weights of subcutaneous fat, muscle and bone were measured. ADG and FC were 279 g and 5.1, 224 g and 6.7, 146 g and 7.7, and 83 g and 11.3 for the control, PEFF25, PEFF50 and PEFF75 diets, respectively. Dressing percentage, adjusted for age, was 422, 437, 414 and 399 g/kg liveweight for the lambs fed the above diets, respectively. The difference between the PEFF25 and PEFF75 diets was significant. Side weights were similar for the control and PEFF25 diets at 12.1 and 11.0 kg, respectively, but significantly lower for the PEFF50 (8.5 kg) and PEFF75 diets (6.8 kg). When calculated on a constant side weight basis (g/kg side weight), lambs fed the PEFF25 diet were 75 g lower in subcutaneous fat, 68 g more in muscle and the same amount of bone as the control lambs. Increasing the proportion of PEFF in the diet from 250 to 750 g/kg feed, did not change the proportion of lean in the lamb carcasses. Lambs fed PEFF50 or PEFF75 diet had a significantly greater proportion of bone in their carcasses compared to the lambs offered the control or PEFF25 diet. The study indicates that PEFF could replace 250 g/kg of the conventional dietary ingredients in diets for growing lambs.

A modified hot processing strategy for beef: effects on fresh meat quality

A modified hot processing (MHP) strategy for beef carcasses using known chilling technology to maintain quality in the higher priced cuts while retaining lower value cuts for further, immediate hot processing was evaluated. Following high voltage electrical stimulation, paired sides from 36 carcasses were either conventionally processed (CP) or reduced in a manner similar to the French pan traité cut. The sides were help in a pre-chiller for 1 h prior to blast chilling at −20°C for 3 h at an air speed of 2·3 m s −1, followed by chilling at 2°C for the remainder of the 24 h period. Overall, MHP of beef carcass sides had minimal effects on fresh meat quality in the longissimus thoracis et lumborum (LTL) and the semimembranosus (SM) muscles despite removing over 50% of the carcass side weight in the form of lower value cuts. Sarcomere length was significantly shorter ( P ≤ 0·05) in the anterior (AL) and posterior (PL) LTL which was attributed to the removal of skeletal restraint and carcass weight. The increase in shear value in the AL, location of MHP sides although statistically significant ( P ≤ 0·05) would not likely be percieved by consumers. Hence a non-traditional method of processing carcasses by treating low value and high value primal cuts separately, may be viable.

Differences in the composition and tissue distribution of pig carcasses due to selection and feeding level

ABSTRACTA total of 96 Large White weaner pigs, comprising equal numbers of entire males and females, and of controls and eighth generation index-selected genotypes, were fed ad libitum until 40 kg live weight. From 40 kg until slaughter at 85 kg live weight pigs within genotype and sex groups were fed either ad libitum or 2·2 times maintenance. The left sides of the carcasses were divided into shoulder, middle and ham portions and the middles further divided into eye, wedge and belly dorso-ventral portions. Tissue dissection was performed on all portions separately.Selected pigs yielded proportionately 0·15 less fat, 0·08 more muscle, a smaller muscle: bone ratio and 4·05 mm less P2 backfat depth than the controls. When the data were adjusted to the same mean P2 fat depth, the carcasses of selected pigs had 0·07 less fat and 0·03 more muscle. There were no appreciable differences between the genotypes in cranio-caudal tissue distribution. However, there were differences in dorso-ventral tissue distribution since the middles of selected pigs had proportionately and absolutely more of each tissue in the belly. There was no evidence that selection against fat at the P2 site had caused any increase in fat lateral to the m. longissimus.Food restriction increased carcass muscle by 0·10 and decreased fat by 0·17, but had no effect on muscle: bone ratio or cranio-caudal or dorso-ventral tissue distribution. At the same carcass side weight and P2 fat depth, restricted feeding decreased fat by 0·10 and increased muscle by 0·06 in the carcass side.It is concluded that carcasses of the selected pigs would be undervalued relative to the controls due to less fat and more muscle at the same weight and P2 fat depth. Also, restriction on food intake can cause carcasses to be undervalued relative to feeding ad libitum.

Composition of pork carcasses by potassium-40 liquid scintillation detection: estimation and validation.

Liquid scintillation detection of potassium-40 was used to estimate pork carcass composition of 124 boars, barrows and gilts. Pigs were fed to five live weights (23, 45, 68, 91 and 114 kg) and 40K emissions were determined on live pigs in a whole body counter (WBC) equipped with a two-pi liquid scintillation detector. Then, pigs were slaughtered conventionally and the right side of each carcass was weighed, 40K emissions of this carcass side was determined in the WBC and total grams of potassium were calculated. The right side of each carcass was ground, sampled and analyzed for fat, protein, moisture and potassium. Fat, protein, moisture and overall potassium percentage means were 23.9 +/- 7.2, 16.5 +/- .94, 57.0 +/- 6.5 and .25 +/- .02, respectively. Whole body counter carcass potassium was highly correlated (P less than .01) to chemically determined carcass potassium (r = .70). Percentage of fat, protein and moisture prediction equations were formed by stepwise regression using the linear, quadratic and interactive effects of live animal and carcass side weight. Whole body counter live animal and carcass potassium and sex were utilized as independent variables. Carcass weight and 40K determined potassium of the carcass explained more of the variation in carcass composition than did live animal weight and 40K determined potassium of the live animal.

Growth performance and body composition of wether lambs implanted at two different initial live weights with trenbolone acetate combined with oestradiol-17β

AbstractThirty-two Border Leicester ♂ × Scottish Blackface ♀ wether lambs, aged about 5 months, were divided into two groups on the basis of live weight, such that group G1 contained the 16 lightest lambs and group G2 the 16 heaviest. Lambs in group G1 were subdivided equally at random either to be sham-implanted controls (Group C1) or to be implanted with 35 mg trenbolone acetate (TBA) + 5 mg oestradiol-17β (OE) (group T1) at 24 kg initial live weight. The lambs in group G2 were also subdivided into two groups (groups C2 and T2), and similarly treated approximately 1 month later at 37 kg initial live weight. The lambs were offered ad libitum a diet containing an estimated 12·5 MJ metabolizable energy (ME) per kg dry matter (DM) and 140 g/kg DM crude protein. Comparisons were made for the main effects of hormonal treatment and initial live weight. Both hormonal treatment and initial live weight gave increases for DM intake, gut fill, empty body weight, carcass weight and, in the half carcass side weight, weights of dissected lean tissue, bone and intermuscular fat and chemically determined DM, crude protein and lipid. Weights of mm. semitendinosus, longissimus dorsi, supraspinatus and gastrocnemius were also increased due to hormonal treatment and in group G2 lambs compared with those in group G1. When expressed as a proportion of carcass side weight, hormonal treatment effects were not significant for individual muscles and dissected carcass lean, bone and fat and chemically determined lipid and ash. Variable effects on other body components were recorded for both treatments in the absence of any significant interactions. The responses to hormonal treatment were essentially similar in groups G1 and G2. The question is raised as to the contribution of the greater food intake in implanted lambs to the maintenance of fatness in these animals.