Effect of electrical stunning on meat and carcass quality in lambs

The effect on meat quality and the presence of haemorrhages were assessed in head-only electrically stunned and non-stunned lambs. Colour (L?, a?, b?), muscle ultimate pH (pHu), chilling losses and carcass weight at 45 min and 24 h were not significantly different between treatments. However, the amount of blood lost relative to live body weight and the killing-out were significantly higher (P<0.05) in electrically stunned lambs compared with non-stunned lambs. No carcasses with petechiae, ecchymosis, haematomas and bone fractures were found in either treatment. On the other hand, the incidence of hearts with petechiae was significantly (P<0.05) higher in electrically stunned lambs compared with lambs slaughtered without prior stunning. It is concluded that meat quality and the incidence of haemorrhages are unaffected by head-only electrical stunning for 3 s at a constant voltage of 250 V.     

Effects of slaughter weight on carcass composition and meat quality in pigs of two different growth rates

Three hundred and forty (340) Duroc×(Landrace×Yorkshire) crossbred piglets were allotted to a 2×2×3 factorial design experiment. The independent variables were the growth rate (fast: around -10 days at 100kg and slow: around +2 days at 100kg), based on two different EBV's (estimated breeding value) of the sire-line for age, the sex (barrows and gilts) and the live weight at slaughter (107, 115 and 125kg). A sub-population of 119 pigs (10 carcasses per treatment) was selected for the carcass and meat quality evaluation trials. As live weight increased there were significant increases in hot carcass weight and dressing percentage (P<0.05). Lean, fat and bone proportions were not affected by weight. Gilts had higher lean proportion (P<0.05) than barrows. Furthermore, carcasses of fast growing pigs were fatter (P<0.05) than those of slower growing ones. Loin muscle pH, drip loss and reflectance values did not vary significantly with any of the treatments. Intramuscular fat was higher in barrows (P<0.05) than in gilts and soluble collagen content decreased with increasing weight (P<0.05). Muscle protein (%) increased (P<0.05) from 107 to 115kg and gilts had a higher (P<0.05) content than castrates. No evidence was found that increasing slaughter weight detracts from carcass characteristics or meat quality.     

The effects of breed and halothane sensitivity on pig meat quality

The effects of halothane sensitivity and breed (Belgian Landrace BL and Landrace L), and their interactions on carcass and meat quality were analysed. Also the effect of breed (Pietrain P, BL, L, Large White LW and Duroc D) on carcass and meat quality was studied in a sample of 153 gilts. Each of the half-carcasses was cut and fully dissected to obtain lean percentage. The following measurements of meat quality were carried out: muscle pH, electrical conductivity (QM) and light scattering (POP). Muscle reflectance (GOFO value), muscle protein solubility (MPS) and intramuscular fat content were also determined. The results obtained in this study revealed the effect of halothane gene on all of the traits studied. The halothane-positive animals showed less fat thickness and more lean percentage in the carcass. The P and BL breeds had more lean percentage in the carcass and a better lean-to-bone ratio compared with L, LW and D. The L breed was intermediate. Stress sensitivity is an important factor affecting the inverse relationship between carcass quality and meat quality. Those breeds free of the halothane gene (LW and D) had the best meat quality. The L breed was in an intermediate position, but more similar to halothane-negative breeds. The Duroc breed had significantly higher intra-muscular fat (>2·0%), required for optimum fresh meat quality and for the production of Spanish dry-cured ham of high quality.     

Halothane genotype and pork quality. 1. Carcass and meat quality characteristics of three halothane genotypes

The carcass and meat quality characteristics of three halothane genotypes in pigs were evaluated. Sixty crossbred Landrace×Large White pigs (NN=25, Nn=19, nn=16) of ±86 kg live weight were slaughtered, the carcasses chilled for 24 h at 2°C, certain carcass and meat quality traits determined and the shoulder and leg cuts deboned and cut into primal cuts. Dressing percentage of the Nn pigs was higher (P<0.05) than that of the NN and nn pigs. Carcass length was the longest (P<0.05) for the nn pigs. Midline fat measurements as well as measurements at the 2nd-3rd last rib (45 mm from the midline) indicated that the nn pigs had less fat (P<0.05) and a larger eye muscle width (P<0.05), depth (P<0.001) and area (P<0.001) than the NN or Nn pigs. This resulted in the nn pigs having the highest (P<0.05) percentage predicted carcass lean content. Fat, bone and lean yield of the shoulder identified the nn pigs with the least bone (P<0.05) and fat (P<0.001) and the highest lean yield (P<0.05), expressed as a percentage of total shoulder weight. Yield from the legs identified the nn pigs as having the lowest fat (P<0.001) and highest lean (P<0.05), expressed as a percentage of total leg weight. The primal lean cuts (topside, silverside, thickflank and rump) from the legs showed that the nn pigs had the highest values (P<0.05) for lean as a fraction of cold carcass weight. This resulted from the higher weight of these cuts (P<0.05) in the nn pigs. Calculation of bone yield in the legs showed that the femur weights were highest (P<0.05) for the Nn pigs, also when expressed as percentage of leg weight (P<0.05) and as a fraction of cold carcass weight (P<0.05). Comparison of meat quality traits show that the nn pigs had poor quality with regard to pH(45) (P<0.001), pH(24) (P<0.05), drip loss (P<0.001) and reflectance values (P<0.05).     

不同饲养条件对苏尼特羊背最长肌中MyomiRs表达及屠宰性能的影响

选择不同饲养条件下12月龄苏尼特羊的背最长肌为实验材料,通过测定6种mi RNAs的表达量及苏尼特羊的屠宰性能,研究不同饲养条件对mi RNAs表达量及屠宰性能的影响。结果表明:放牧苏尼特羊生长性状(体长、体高、胸围)、宰前活质量、胴体质量均显著高于圈养(P0.05),圈养苏尼特羊屠宰率、净肉率高于放牧。放牧苏尼特羊mi RNAs表达量均高于圈养苏尼特羊。放牧苏尼特羊mi R-1表达量与体高、胴体质量、净肉质量、净肉率显著正相关(P0.05),mi R-133表达量与净肉质量呈显著正相关性(P0.05),圈养苏尼特羊mi R-128表达量与净肉率显著负相关(P0.05)。说明不同饲养条件对mi RNAs的表达有影响,进一步影响屠宰性能。     

Electromagnetic scanning to estimate carcass lean content of Taiwan native broilers

To estimate lean content of Taiwan native broiler carcasses accurately, objectively and rapidly, electrical conductivity measurements of broiler carcasses and other relative factors (carcass weight, length and temperature) were used in multiple linear regression analysis for lean prediction. Forty native broiler carcasses, with average market weight 2477.5±465.5 g, were scanned through a 10 MHz electromagnetic field created by an electromagnetic scanner (SA-3203) to measure the total body electrical conductivity (TOBEC) index. After scanning, each broiler carcass was separated into wing, breast, leg and back. Each primal cut was dissected into lean, fat and bone. The weight, length, temperature and TOBEC index of broiler carcass were significantly correlated with lean weight of broiler carcass (P<0.001). Regression analysis for lean estimation with carcass weight, length, temperature and TOBEC index showed higher coefficient of determination (R(2)=0.968) and lower coefficient of variation (CV=4.178) with an equation using beheaded carcass weight, temperature and TOBEC index as variables.     

不同屠宰方式对新疆多浪羊肉品质的影响

以新疆多浪羊为研究对象,对比分析传统屠宰（对照）和3 个不同电压（90、127 V和220 V）击晕屠宰 （分别计作EST 90、EST 127、EST 220）对多浪羊肉品质的影响。结果表明：EST 90处理组成熟过程中pH值下降 速率最快,血液中的皮质醇浓度、肌酸激酶和乳酸脱氢酶活力最高,羊应激反应最剧烈,宰后1、7 d的蒸煮损失率 最高（P＜0.05）;EST 127处理组的持水力最好;电击晕对多浪羊肉嫩度有一定影响,宰后7 d各处理组嫩度显著 改善,而EST 127处理组表现最佳;EST 220处理组放血不充分,且胴体表皮有多处血斑形成;电击晕屠宰对多浪羊 肉色泽无显著影响（P＞0.05）。综合分析实验结果,EST 127处理组持水力与嫩度较优,羊应激反应较小,肉品质 相对较好,因此EST 127处理适合应用于多浪羊的屠宰加工。     

Effect of rate of pH decline on muscle enzyme activities in two pig lines

Muscle enzyme activities were measured in m. transversus abdominis (TA) samples of two pig lines, differing in stress sensitivity and in breeding objectives. Animals of line one were stress sensitive and selected for a high carcass lean content (LEAN), those of line two were homozygous stress resistant and selected for maximum live weight gain (GROWTH). Muscle samples of 16 pigs per line were excised at 1 h and sampled at 3 h post mortem. Boars, gilts and barrows were almost equally represented. Pigs of line GROWTH had a higher fat and lean tissue gain (P<0.01) and a lower carcass lean content (P<0.001) than those of line LEAN. Lower activities of μ-calpain, m-calpain, pyroglutamyl aminopeptidase I, acid lipase and neutral phospholipase were measured in TA muscle samples of line LEAN compared with line GROWTH (P<0.05). Activities of dipeptidyl peptidase IV and acid phospholipase tended to be somewhat lower for line LEAN, whereas activities of calpastatin, cathepsin (B+L) and cathepsin D were not different. Sex-class effects were analogous to line effects. Significant correlation coefficients between activities of several enzymes and pH values 1 h post mortem, both within and across lines, suggest that lower enzyme activities are a consequence of a more pronounced denaturation due to a faster post mortem pH decline.     

Characterisation of young bulls of the Bruna dels Pirineus cattle breed (selected from old Brown Swiss) in relation to carcass, meat quality and biochemical traits

Seventy-four young bulls of the Bruna dels Pirineus beef cattle breed were reared in a typical production system and slaughtered at an average age of 381 days and live weight of 541 kg. The animals were evaluated for productive traits, carcass quality, meat quality, eating quality and biochemical characteristics of m. longissimus thoracis (LT). Biochemical measurements included intramuscular fat (IMF) and collagen proportion, haem pigment concentration, lactate dehydrogenase and isocitrate dehydrogenase activities and type I (MHC I) fibre percentage determined by ELISA. Bruna dels Pirineus bulls achieved high growth rates during the fattening period (1.63 kg/day) and showed good carcass quality, with a high dressing-out proportion (607 g/kg, hot carcass), a good conformation score (U; EUROP) and a moderate fatness score (3;1-5). Carcass composition was estimated from the sixth rib joint dissection (682 g/kg lean proportion, 127 g/kg total dissectable fat and 163 g/kg bone). IMF (24.3 g/kg) and MHC I (27.9%) showed high variabilities (CV>30%). Sensory analysis of LT included beef and livery odour and flavour intensity, and overall tenderness and juiciness assessment of loin samples (14-day ageing). Beef odour and flavour were slightly positively correlated with IMF and carcass fatness score (P<0.05). Fatness, MHC I, insoluble collagen and cooking losses tended to affect the livery flavour intensity positively. This variable was significantly higher in meat from bulls of lower carcass quality (i.e. lower conformation score, lower lean proportion; P<0.05) and higher type I fibre percentage. Loin overall tenderness and juiciness were not affected by the biochemical traits studied, however, they were negatively affected by cooking loss (P<0.05).     

The effect of stunning method on the incidence of PSE meat and haemorrhages in pork carcasses

Two commercial pig abattoirs (A and B) equipped with a head-only and head-to-chest electrical stunning systems, and two (C and D) equipped with compact carbon dioxide (CO(2)) stunning systems, were visited during 3 days to evaluate the effects of the stunning system on meat quality and haemorrhages. Meat quality was evaluated by measuring muscle electrical conductivity (PQM) and colour (Minolta Chromameter) at 2 and 7 h post mortem (abattoirs A and C, and B and D, respectively). PQM and colour were measured in 2486 and 2321 loins respectively. Also ultimate pH (pHu) was measured in 2395 loins at 24 h post mortem. Haemorrhages were evaluated by recording the incidence of petechiae, ecchymosis and haematomas, bone fractures were also recorded. A total of 1980 shoulders, 3943 loins, and 5438 hams were inspected. In the abattoirs equipped with the electrical stunning systems, a higher (P<0.05) incidence of potentially PSE meat (PQM>6) was found compared with the abattoirs equipped with CO(2) stunning. Likewise, the loins from electrically stunned pigs were paler than those from CO(2) stunned pigs (P<0.05). Electrical stunning increased the incidence of petechiae in the loin and the ham (P<0.05). No shoulder, loin or ham with bone fractures was found in the abattoirs studied. Therefore, CO(2) stunning reduces the incidence of PSE meat and of petechiae on muscle fascia of loins and hams, compared with electrical stunning. However, petechiae are not of great importance because they can be removed from the affected commercial cuts.     

The effect of increasing carcass weight of finishing boars and gilts on joint composition and meat quality

Two hundred and eighty-eight crossbred (3/4 Landrace × 1/4 Large White) pigs, comprising equal numbers of boars and gilts, were housed in single sex groups from 50 kg liveweight to slaughter at liveweights of 92, 105, 118 and 131 kg (carcass weights of 70, 80, 90 and 100 kg). Sample joints from the left longissimus dorsi muscle were obtained at slaughter for dissection and meat quality assessment. As carcass weight increased there were significant (p<0.001) increases in eye muscle area and subcutaneous fat content. Lean content decreased (p<0.001) with increasing carcass weight while intermuscular fat content was not affected. There was a significant interaction between carcass weight and gender with % drip loss in pork from gilts at 100 kg having a higher drip loss than boars and gilts at all other weights. There were small but significant (p<0.01) reductions in ultimate pH with increasing carcass weight. Cooking loss was also reduced (p<0.001) at the heavier weights. There was no effect of carcass weight on shear force or on intramuscular fat. Dry matter (DM) and crude protein (CP) contents of m. L. dorsi increased (p<0.001) at heavier weights while sarcomere length decreased (p=0.001). Compared with boars, gilts had greater eye muscle area (p<0.05), more subcutaneous fat (p<0.001). Meat from gilts in comparison with boars had higher % DM and % CP contents (p<0.001), higher intramuscular fat content and shear force (p<0.05). It is concluded that meat quality may be improved when carcass weight is increased from 70 to 100 kg. ?     

The influence of dietary protein on market barrows and gilts supplemented creatine monohydrate in conjunction with a high glycemic carbohydrate

The objective of the study was to determine if additional dietary protein improves the lean tissue deposition and carcass merit of pigs supplemented creatine monohydrate in combination with a high glycemic carbohydrate (dextrose). Forty-eight crossbred barrows and gilts (91±0.18 kg) were blocked by sex assigned to 1 of 12 pens (4 pigs/pen, 16 pigs/treatment). Treatments included: control (CON; basal diet consisting of a ground corn-soybean base), combination diet (COMBO; basal diet supplemented with 0.92% creatine monohydrate and 2.75% dextrose), and a combination high protein diet (COMBOHP; COMBO formulated to contain a minimum of 16% crude protein). Barrows on the COMBOHP gained the least 10th rib fat and expressed the highest percentage fat-free carcass lean (P<0.01) after 28 days on test. No significant treatment differences were noted in the fat and lean tissue accretion of gilts. Treatments had no affect the meat quality parameters of barrow and gilt carcasses.     

Effect of cardiac arrest on susceptibility to carcass bruising in sheep

The effect of inducing a cardiac arrest at electrical stunning on the susceptibility of the carcass to bruising was evaluated in thiopentone-anaesthetised sheep. Bruising was induced with a percussion pistol and measured in terms of meat appearance and extractable haem pigment. Cardiac arrest caused a prompt and marked reduction in susceptibility to bruising, and it is concluded that stunning techniques which cause simultaneous heart failure could help to reduce the incidence of carcass bruising. Exsanguination of sheep which had a normal cardiac rhythm prevented the induction of bruising once 50% of the total blood loss had occurred.     

Effect of sex and terminal sire genotype on performance, carcass characteristics, and meat quality of pigs slaughtered at 117 kg body weight

The effects of gender (barrows; gilts) and terminal sire genotype (DD, Danish Duroc; PxLW, Pietrain×Large White) on performance and carcass and meat quality of pigs sacrificed at a fixed weight of 117 kg were studied. Barrows ate more feed, grew faster, and had poorer feed conversion and less yield of trimmed lean cuts than gilts. Castrates were fatter and had more intramuscular fat and more intense colour of the meat than females. Crossbreds from DD boars grew faster and had better feed conversion than crossbred from P×LW boars. Also, DD sired-pigs had smaller dressing percentages but more trimmed lean cuts proportion than P×LW sired-pigs. Meat from DD pigs was more tender, had more intramuscular fat, and presented lower a* value than meat from P×LW pigs. We conclude that DD boars are a good alternative to P×LW boars for production of heavy pigs destined for the dry-cured industry.     

Influences of dietary conjugated linoleic acid (CLA) and total lysine content on growth, carcass characteristics and meat quality of heavy pigs

To assess the effects of dietary CLA, lysine and sex on performance, blood metabolites, carcass characteristics, meat quality and skeletal development, seventy-two pigs (initially 105.3 ± 6.6 kg live weight) barrows and gilts, were assigned to one of four diets in a 2 × 2 × 2 factorial arrangement. The diets contained 0% or 0.75% CLA, and 0% or 0.16% of l-lysine–HCl. All pigs were slaughtered at an average weight of 153.4 ± 11.0 kg. Neither CLA nor lysine supplementation influenced growth, blood metabolites or carcass characteristics. CLA reduced (P < 0.05) pH₂₄ and increased (P < 0.01) yellowness (b^*) of the Longissimus muscle. Lysine increased (P < 0.01) pH₂₄ and reduced (P < 0.01) muscle ash content. CLA reduced (P < 0.05) collagen synthesis, and lysine increased (P < 0.05) collagen synthesis in Longissimus muscle, but no influence on intramuscular collagen maturity or muscle hydroxylysylpyridinoline crosslink concentration were observed. In addition, metacarpal bone diameter was reduced (P < 0.05) by CLA. Barrows had higher ADG, final weight (P < 0.01), carcass weight, lean percentage (P < 0.05), serum cholesterol (P < 0.05) and triacylglycerol (P < 0.001) than gilts. Metatarsal diameter was larger in gilts than barrows (P < 0.05).     

Relationships of fat-tail dimensions with fat-tail weight and carcass characteristics at different slaughter weights of Torki-Ghashghaii sheep

The purpose of this research was to investigate the relationship between fat-tail and carcass attributes in Torki-Ghashghaii sheep. Thirty ram lambs belonging to six weight groups (weighing from 25 to 50kg) were used. Fat-tail measurements were recorded on the live animals before slaughter. Hot and cold (after 24h in the cold room) carcass weights, and the weights of the tail and internal organs were recorded. The carcass was dissected into conventional cuts. Each cut was de-boned and the physically separable fat was removed from the meat. The bone, physical fat and trimmed meat were weighed separately. The weight of trimmed meat as a percentage of slaughter weight did not change significantly from 25 to 50kg live weights (23.4-25.3%). The weights of physically separated fat and the fat-tail as a percentage of live weight varied from 6.6% to 15.5% for various weight groups. The correlation coefficients between the tail weight and dimensions were large, positive, and significant. The highest correlation coefficient was found between the tail weight and upper circumference (r=0.88), and the lowest one was found between the tail weight and upper thickness (r=0.61). The upper and lower circumferences of the tail accounted for 85% of the total variation in the tail weight. The tail weight was positively correlated with the meat chemically determined fat (ether extract; r=0.43; P<0.05) and with the total body fat (r=0.70; P<0.01). Further studies are needed to see whether inclusion of fat-tail measurements in breeding programs would result in a decrease in body fat in this breed.     

Prediction of lean meat content in pork carcasses using the Hennessy Grading Probe and the Fat-O-Meater in Argentina

Rapid evolution of pork production in Argentina requires new calibrations for predicting carcass lean meat percentage with the Fat-O-Meater (FOM) and Hennessy Grading Probe (HGP), first adopted in 1995. The second objective was to unify the lean percentage units with those applied by the European Union. Carcasses of 59 gilts and 56 barrows from different environments and breeds were tested. Carcass weights were from 65 to 117kg, and lean content was from 38% to 62%. Predicting lean content by multiple regression equations, the coefficients of determination R(2) were 0.801 and 0.794 for the FOM and HGP equations, and the residual standard deviations (RSD) were 2.40% and 2.45%, respectively. Both instruments had the same precision and were accurate enough to be adopted in national carcass grading classification. Hot carcass weight was not selected as a significant variable. The same prediction equations could be used for gilts and barrows. Quadratic terms did not improve predictions.     

Carcass and meat quality in double-muscled Belgian Blue bulls and cows

Carcass and meat quality of 37 bulls and 91 cows of the Belgian Blue breed (double-muscled type) were compared. Age at slaughter averaged 648±73 and 1820±689 days, respectively. Both groups of cattle were finished on maize silage supplemented with concentrate, and were slaughtered at about 750 kg live weight. Females had a lower (P=0.004) cold carcass weight (469.7 kg) in comparison with bulls (500.8 kg), due to a reduced dressing percentage (63.8 vs. 66.6; P <0.001). SEUROP conformation was better for bulls. SEUROP fat covering (P=0.007) and fat content in the carcass (16.4 vs. 12.9%; P <0.001) and in the M. longissimus thoracis (LT) muscle (2.3 vs. 1.1%; P <0.001) were higher for females than for males. The LT of cows was darker (lower L* and higher a*-value; P <0.001), had a better waterholding capacity (P?0.063) and was slightly more tender (P=0.120) than the LT of bulls. Increasing parity reduced dressing percentage and increased LT lightness (L*-value) in cows. Several carcass (SEUROP-grading, composition, LT-area) and meat quality traits (protein and fat contents, drip and cooking losses, a*-value) were better correlated with carcass weight than parity. It is concluded that meat quality of the aged LT of cows is not negatively affected by age, while some carcass quality traits decreased with advancing age. Carcass quality traits adjusted for age at slaughter were better for bulls, but LT meat quality characteristics were at least as good for females as for males.     

Carcass and meat characteristics of the Nile crocodile (Crocodylus niloticus)

Seven Nile crocodiles (Crocodylus niloticus) of 1300 mm length were slaughtered in order to established baseline values for component yields and expected percentage of lean meat, fat and bone for this species. The skin presents nearly 20% of the live weight of the Nile crocodile, while a dressing percentage of 56.5% was derived. The tail realised 18 and 33% of the live weight and empty carcass weight respectively. Values of 60.8, 12.2 and 26.6% of carcass weight were obtained for total lean meat, fat and bone respectively. A pH value of ± 6.5 at 24 h post‐mortem in both tail and leg muscles and a decreasing pH towards 48 h post‐mortem illustrated that rigor mortis is still not complete when crocodile carcasses are processed. While fat content differed statistically (P < 0.05) from 91.1 g kg⁻¹ in raw torso samples to 29.4 g kg⁻¹ in raw neck samples, protein content was relatively constant around a mean of 220.8 g kg⁻¹ in raw meat. Cooking did not have any influence of practical value on proximate, amino acid or mineral composition. Crocodile meat is characterised by a lower iron, magnesium and sodium content than either beef or chicken. Of the total fatty acids present in the tail samples, 37.7% were saturated, 51.1% monounsaturated and 10.7% polyunsaturated. Oleic acid was predominant (43.1%), whilst palmitic acid (25.4%), stearic acid (9.9%) and linoleic acid (9.1%) were also present in high concentrations. © 2000 Society of Chemical Industry     

Effect of the insulin-like growth factor-II and RYR1 genotype in pigs on carcass and meat quality traits

Recently, a new QTN (quantitative trait nucleotide), which is located in the regulatory sequence of the imprinted IGF-II gene was discovered in the pig and is associated with a significant increase in IGF-II mRNA expression in skeletal muscle during postnatal growth. The aim of the current study was to investigate the effect of the IGF-II paternal allele (Apat and Gpat animals that inherited, respectively, the mutant and wild type paternal allele of interest) on carcass and meat quality traits in Nn and NN RYR1 genotypes. A total of 141 animals were measured, almost equally distributed over the IGF-II and RYR1 genotypes and gender. The Apat allele increased carcass lean meat percentage with approximately 4.5% (P < 0.001) as a result of decreased backfat thickness. Average live weight daily gain was not affected, hence average daily lean meat gain was significantly higher for Apat compared to Gpat animals. The IGF-II mutation had no noticeable effect on meat quality in contrast with the RYR1 mutation. No interaction effects of both mutations on meat quality were noticed.