Content Of Carcasses Research Articles

Relationships between pig farm management and facilities and lung lesions' scores and between lung lesions scores and carcass characteristics

BackgroundThe objective of this study was to examine the inter-relationships between pig farm management and facilities (as assessed by questionnaire) and post-mortem lung lesion (lung score assesment), which are the result of respiratory infections. The relationships between carcass characteristics and post-mortem lung lesion scores were also investigated.ResultsQuestionnaire responses were collected from 22 self-selecting pig farmers about their farm facilities/management and health condition of the respiratory system of pigs, including the occurrence of clinical respiratory signs, results of laboratory testing for respiratory pathogens, and the use of respiratory vaccines. When fatteners were sent to the abattoir, their carcasses (n = 1,976) were examined for evidence of respiratory disease by lung lesion (pleuritis pneumonia-like (PP-like) and enzootic pneumonia-like (EP-like) lesions) scoring and the Actinobacillus pleuropneumoniae Index (APPI) was calculated. Carcass characteristics were recorded and, retrospectively, the prevalence of cachectic pigs was calculated. Using these variables, the relationships between farm facilities/management and lung lesions scores and the relationships between the latter and carcass characteristics and cachexia were explored. The key findings relating farm facilities and management to lung lesions were: slatted floors were associated with significantly higher EP-like lesions scores than litter bedding in weaners, single-stage fattening in the same building was associated with significantly higher EP-like lesions scores than two-stage fattening, but herd size, stocking density, use of all-in/all-out (AIAO) rule, technological break duration and variation in daily temperature did not affect lung lesions scores. The key findings relating lung lesion scores to carcass characteristics were: a significant, negative correlation between EP-like scores and carcass weight but not with other carcass characteristics, a significant positive correlation between PP-like scores and carcass meat content and prevalence of cachectic carcasses and a significant positive correlation between lung APPI and prevalence of cachectic carcasses.ConclusionsIt can be concluded that both farm facilities and management affect lung lesions scores and that the latter affect carcass characteristics. Lung lesion scoring is an inexpensive technique suitable for rapid monitoring of large numbers of carcasses that can be performed after animal slaughter. It provides useful information to inform producers about possible deficits in farm facilities or management and is a predictor of economic loss due to poorer quality carcasses.

Use of defatted fermented rice bran in the diet of juvenile mullets Mugil liza

The study aimed to evaluate the use of increasing levels of defatted rice bran fermented by Rhizopus oryzae in the diets of juveniles of mullet fish Mugil liza, assessing growth parameters, proximal carcass composition, and lipid peroxidation (TBARS) in the liver and intestine. Six experimental diets were formulated: a control treatment without rice bran, a second treatment with the inclusion of 200 g kg−1 of defatted rice bran without fermentation (DRB200), and the remaining treatments received diets with the inclusion of 100, 200, 300, or 400 g kg−1 of fermented bran. The experimental design used 216 mullet juveniles (2.10 ± 0.04 g) randomly distributed in a recirculation system composed of 18 tanks, divided into six treatments and three replications, with 12 fish per experimental unit. During the experiment, fish were fed ad libitum three times a day, for 50 days. No mortalities were recorded during the experimentation. The performance variables showed that an inclusion equal or higher than 200 g kg−1 of fermented rice bran resulted in decreased growth. Furthermore, in carcass proximal composition, the lipid content decreased with higher inclusion levels of fermented rice bran and the control treatment showed the highest lipid content, while the ash content of fish carcasses increased with the higher inclusion of the tested ingredient. No differences were recorded for TBARS in the liver and intestine. According to the results, we recommend a maximum inclusion of 100 g kg−1 fermented rice bran in diets for M. liza juveniles.

The analysis of pig carcass classification in Slovakia

In the last decade, the pig sector in Slovakia has been changing continuously, especially in regard to the proportion of pigs coming from foreign breeding programs. These changes lead to changes in carcass characteristics and to a change in the distribution of carcasses within the classes of the Union scale for the classification of pig carcasses. Therefore, this study was undertaken to analyse the actual state of pig carcass classification in the Slovak Republic and to investigate the needs of updating the equations for the classification methods and possible steps to improve the quality of pork produced within the country. Results showed that an increased number of pig carcasses originated from Danish breeding program, and also from the Czech Republic and Poland. When compared to carcasses in 2009, these changes resulted in lower backfat thickness and higher muscle thickness of the longissimus dorsi muscle and thus higher lean meat content of carcasses. This results in a higher number of carcasses classified in the S and E classes. Slight differences between two instrumental classification methods were calculated. The study showed the need for updating the equations for classification methods, and also suggested possible further steps in order to improve the quality of pork.

Effects of the Dietary Inclusion of Buriti Oil on Lamb Performance, Carcass Traits, Digestibility, Nitrogen Balance, Ingestive Behavior and Blood Metabolites.

Simple SummaryDietary fat is important for animals, not only because it supplies essential fatty acids and fat-soluble vitamins, but also because of its high energy content, approximately twice as many calories per gram of carbohydrates. Thus, it induces a caloric increase, in addition to modulating the fatty acid (FA) profile of meat. Vegetable oils inclusion in the diet of lambs improves the lipid quality of meat. Among them, buriti oil (Mauritia flexuosa L.F.) is an example that stands out; it can represent an important alternative to meet the energy demands of lambs, particularly because of its easy availability, especially in the northern and northeast states of Brazil. In addition, as a consequence of the high cost of protein supplements in feed concentrates, unconventional alternatives have been exploited in recent years. Thus, this research proposes the use of a byproduct of the biofuel industry. This study was conducted to enhance our knowledge of interesting opportunities for farmers in terms of lamb meat production. Its use could promote activity in the livestock sector by reducing feed costs and becoming an alternative to producers without easy access to more expensive supplements.Buriti (Mauritia flexuosa L.) oil (BO) is a byproduct that can be incorporated into the diet of lambs, thus increasing the energy density. The study aimed to evaluate the optimum BO inclusion level in lamb diets. Sixty-five Santa Ines lambs were distributed in two completely randomized experiments with five treatments each (BO inclusion at 0 (control), 12, 24, 36 and 48 g/kg dry matter (DM) total). The BO supplementation to partially replace ground corn linearly decreased the nutrient intake and digestibility of DM, ether extract and neutral detergent fiber (NDF), N° chews/bolus, DM and NDF rumination or eating efficiencies, the N intake and N balance, carcass weights and yields, and dressing content of lamb carcasses (p < 0.05). The addition of BO responded quadratically to DM eating efficiency and N-fecal and N-urinary excretion (p < 0.05). The linear response plateau (LRP) analysis demonstrated that the levels of 0 and 12 g/kg of BO were similar, and improved intake and digestibility and consequently performance (p < 0.001). There was a linear increase in feed efficiency and shrinkage after chilling with the BO inclusion replacing ground corn. The inclusion of 12 g/kg BO in the total DM of diet is recommended, because it improves feeding intake, digestibility and performance of lambs.

Nutrient and moisture transfer to insect consumers and soil during vertebrate decomposition

Decomposition of organic matter leads to the redistribution of nutrients to organisms and the environment. Yet knowledge of this process has focused largely on plant-derived organic matter, with little known about relative quantities of nutrients and moisture transferred from decomposing animal remains to insect consumers and soil. We used a replicated and spatially blocked experiment to quantify the moisture, carbon, nitrogen, and phosphorous content of rabbit carcasses, maggot consumers, and soil over 20 days of decomposition.We found that maggot biomass reached 22% of the fresh rabbit carcass, or 39% of the consumable soft tissues. Maggots were comprised of 68% moisture, and their dry mass was comprised of 25% carbon, 4.9% nitrogen, and 0.8% phosphorous. Soils accumulated approximately 12.9% of the total carcass moisture, but only 0.7% of the carcass dry mass. The largest quantity of carcass mass loss was attributable to evaporation of moisture to the atmosphere (45%). Approximately 9% of the initial carcass mass was left as unconsumed remains. Our study provides estimates of the quantities of nutrients moving from vertebrate carcasses to insect consumers and soil. This knowledge is critical to scaling up the effects of carcasses and to developing our understanding of their role in biogeochemical cycling in ecosystems.

Effect of chitosan on production performance of feedlot lambs

AbstractIntake, digestibility, nitrogen (N) balance, microbial protein synthesis, weight gain, yields of the main commercial cuts and carcass morphometric measurements were evaluated in lambs fed diets containing different levels of chitosan. Sixty Santa Inês crossbred sheep with an average body weight (BW) of 24 ± 2.2 kg were assigned to three treatments (diets containing 0, 136 or 272 mg chitosan/kg BW) in a completely randomized design. There was no effect of chitosan on dry matter (DM) intake. Ingested and retained N showed a quadratic response, with the highest values estimated at the chitosan levels of 142 and 152 mg/kg BW, respectively. Similar to N balance, microbial protein synthesis showed the same quadratic response, in which the level of 136 mg/kg BW resulted in higher synthesis when compared with the other levels. No effect of chitosan was detected on average daily gain, final weight, or carcass variables (hot carcass weight, cold carcass weight, yield of commercial cuts and morphometric measurements of the carcass). Conformation, visceral fat content and fatness of carcasses were also not altered by the use of chitosan. Chitosan improves the digestibility of DM, crude protein and neutral detergent fibre, and increases N balance and microbial protein synthesis but does not change the production performance of feedlot lambs.

The analysis of meat and bone traits of Plymouth Rock cockerels and capons (P55) at different age

The aim of the study was the comparison of Plymouth Rock cockerels and capons and the evaluation of the influence of their age on slaughter yield, meat quality, and bone traits. The studies were conducted on cockerels and capons from P55 strain (Plymouth Rock). At 16, 18, and 20 wk of rearing, a dissection of whole carcasses of cockerels and capons was conducted, and breast and leg muscles were evaluated in terms of the physical and chemical traits, as well as the chemical composition. Also, traits of femur and tibia bones were studied. It was indicated that capons were characterized by a higher body weight (BW) before slaughter and higher weight of the eviscerated carcass than cockerels at consecutive dates of slaughter. Based on BW, the slaughter yield and muscle content of carcasses, it was found that the most optimal slaughter time in Plymouth Rock cockerels is at 18 wk and capons at 20 wk. It was observed that caponization had a significant effect on the chemical composition of breast muscles with respect to water and protein content. Along with bird age, collagen content in muscles decreased; however, significant differences were observed only in capons. At consecutive dates of evaluating cockerels, resistance and toughness of their femur and tibia bones increased significantly. Significant changes in the physical characteristics of bones were also found.

Using Dual Energy X-Ray Absorptiometry (DXA) For A Rapid, Non-Invasive Carcass Fat and Lean Prediction in Beef

ObjectivesThe objective of this study was to evaluate the potential use of the dual energy X-ray absorptiometry (DXA) for estimating total lean, fat and bone content of beef carcasses and main primal cuts. Materials and MethodsTo represent the majority of commercial cattle, the animal population used (n = 316) to develop and validate the prediction models was selected within a grid based on live weight at slaughter and grade fat. Following normal commercial slaughter and chilling, left carcass sides were fabricated using the Institutional Meat Purchase Specifications (IMPS) for Fresh Beef Products, Series 100. The primals collected included the chuck (IMPS #113), rib (IMPS #103), brisket (IMPS #118), flank (IMPS #193, non-trimmed), foreshank (IMPS #117), loin (IMPS #172A), round (IMPS #158A) and plate (IMPS #121). Each primal cut was scanned with a Lunar iDXA unit (GE Lunar Lunar Prodigy Advance, General Electric, Madison, WI, USA) using the whole body scan option on standard mode to estimate DXA fat, lean and bone tissues. After scanning, all left primal cuts were fully dissected into subcutaneous fat, intermuscular fat, body cavity fat, lean, and bone and then weighed. ResultsRegression and partial least square regression (PLSR) were used to evaluate the relationship of DXA lean, fat and bone values from primal cut scans to cut-out values from manual dissection. Using linear regression, R² (i.e., the % of variation accounted for by the model) for total carcass lean, fat and bone were 0.88, 0.95 and 0.53, respectively. Within individual primals, R² for lean, fat and bone ranged from 0.26 to R² = 0.90, with the highest R² generally for fat, and the lowest predictions generally for bone. Industry applications of this technology for total lean, fat and bone would be expected to achieve these levels of prediction robustness. Using PLSR analyses, which consider all the DXA scan information from all primals as independent variables, overall R² for total carcass lean and fat were both 0.98. PLSR improved the lean prediction for most of primal cuts yielding R² over 0.94 for the brisket, foreshank and flank. The highest R² were observed for the chuck (R² = 0.99), round (R² = 0.98) and loin (R² = 0.97). Similar to lean, PLSR increased the R² for fat predictions; with all being higher than 0.91, excluding the foreshank (R² = 0.77). The highest R² for fat were observed for the flank (R² = 0.98), rib, plate and loin (R² = 0.97). ConclusionDXA was able to be used to develop robust equations for estimating total lean and fat in carcasses normally encountered in the market. Both linear and PLSR equations will provide realistic estimations of the potential utility of DXA within an industry environment, to improve estimations of lean meat yield. In research, DXA coupled with PLSR will also be able to replace manual cut-outs which are destructive, time consuming and costly.

Using Dual Energy X-Ray Absorptiometry (DXA) For A Rapid, Non-Invasive Carcass Fat and Lean Prediction in Beef

ObjectivesThe objective of this study was to evaluate the potential use of the dual energy X-ray absorptiometry (DXA) for estimating total lean, fat and bone content of beef carcasses and main primal cuts. Materials and MethodsTo represent the majority of commercial cattle, the animal population used (n = 316) to develop and validate the prediction models was selected within a grid based on live weight at slaughter and grade fat. Following normal commercial slaughter and chilling, left carcass sides were fabricated using the Institutional Meat Purchase Specifications (IMPS) for Fresh Beef Products, Series 100. The primals collected included the chuck (IMPS #113), rib (IMPS #103), brisket (IMPS #118), flank (IMPS #193, non-trimmed), foreshank (IMPS #117), loin (IMPS #172A), round (IMPS #158A) and plate (IMPS #121). Each primal cut was scanned with a Lunar iDXA unit (GE Lunar Lunar Prodigy Advance, General Electric, Madison, WI, USA) using the whole body scan option on standard mode to estimate DXA fat, lean and bone tissues. After scanning, all left primal cuts were fully dissected into subcutaneous fat, intermuscular fat, body cavity fat, lean, and bone and then weighed. ResultsRegression and partial least square regression (PLSR) were used to evaluate the relationship of DXA lean, fat and bone values from primal cut scans to cut-out values from manual dissection. Using linear regression, R² (i.e., the % of variation accounted for by the model) for total carcass lean, fat and bone were 0.88, 0.95 and 0.53, respectively. Within individual primals, R² for lean, fat and bone ranged from 0.26 to R² = 0.90, with the highest R² generally for fat, and the lowest predictions generally for bone. Industry applications of this technology for total lean, fat and bone would be expected to achieve these levels of prediction robustness. Using PLSR analyses, which consider all the DXA scan information from all primals as independent variables, overall R² for total carcass lean and fat were both 0.98. PLSR improved the lean prediction for most of primal cuts yielding R² over 0.94 for the brisket, foreshank and flank. The highest R² were observed for the chuck (R² = 0.99), round (R² = 0.98) and loin (R² = 0.97). Similar to lean, PLSR increased the R² for fat predictions; with all being higher than 0.91, excluding the foreshank (R² = 0.77). The highest R² for fat were observed for the flank (R² = 0.98), rib, plate and loin (R² = 0.97). ConclusionDXA was able to be used to develop robust equations for estimating total lean and fat in carcasses normally encountered in the market. Both linear and PLSR equations will provide realistic estimations of the potential utility of DXA within an industry environment, to improve estimations of lean meat yield. In research, DXA coupled with PLSR will also be able to replace manual cut-outs which are destructive, time consuming and costly.

Effects of the origin and caponisation on carcass and meat traits in cockerels and capons aged 18 weeks

The aim of the present research was to evaluate the effect of the origin and caponisation on selected slaughter traits and quality indicators of meat in cockerels and capons of strains N88 (New Hampshire), R55 (Rhode Island Red), S11 (Sussex), and P55 (Plymouth Rock). The slaughter yield, breast muscle weight, percentage share of muscles in total in the carcasses, and fatness in general did not differ between the cockerels and capons within the evaluated strains. The trait that mostly distinguished cockerels from capons of strain N88 was the weight of leg muscles. Similarly, the fat content of carcasses expressed with the weight and percentage share of the skin with subcutaneous fat and abdominal fat did not differ between the evaluated groups of cockerels and capons. However, the weight of the leg muscles varied depending on the origin of cockerels and capons. As for the physiochemical properties of meat as well as its chemical composition, no significant differences were recorded in 18-week-old birds. The only obvious effect of the origin and caponisation was found on varied contents of fat in breast muscles in cockerels of strains N88 and P55, and capons of strain P55.

Resistance Phenotypes and Genotypes of Salmonella enterica subsp. enterica Isolates from Feed, Pigs, and Carcasses in Brazil

Salmonella enterica subsp. enterica plays a role as a foodborne pathogen worldwide. The consumption of contaminated pork has been associated with human salmonellosis and the increase in antimicrobial resistance among Salmonella from pigs and pork products is a concern. A total of 225 Salmonella isolates from feed mills, the lairage environment, and the intestinal contents of pigs and carcasses were investigated for their antimicrobial susceptibility. A MIC for ciprofloxacin was screened by agar dilution, and antimicrobial resistance genes were investigated by PCR assays. Among the tested isolates, 171 (76%) showed resistance to at least one antimicrobial agent, and 91 (40.4%) were multiresistant. Resistance occurred most frequently to tetracycline (54.5%), sulfonamides (39.6%), and streptomycin (33.7%). Thirty-two (94.1%) nalidixic acid-resistant isolates exhibited decreased susceptibility to ciprofloxacin. The resistance genes found were blaTEM (ampicillin), tet(A) (tetracycline), tet(B) (tetracycline/minocycline), sul1, sul2, and sul3 (sulfonamides), catA1 (chloramphenicol), floR (florfenicol/chloramphen- icol), strA and strB (streptomycin), aph(3')-Ia (kanamycin), aac (3)-IIa and aac (3)-IVa (apramycin/gentamicin), aadA variant (streptomycin/spectinomycin), and dfrA1 (trimethoprim). Salmonella isolates from pig feces and carcasses displayed a higher frequency of resistance to most antimicrobials tested than isolates from feed mills. Common resistance gene profiles were found in isolates from the lairage and the intestinal content of pigs and carcasses, demonstrating that resistance genes selected on farms may be found in pork.

Bayesian modelling to identify the risk factors for Yersinia enterocolitica contamination of pork carcasses and pluck sets in slaughterhouses

The probability of contamination by pathogenic Yersinia enterocolitica of carcasses and pluck sets at slaughterhouse was determined by means of a Bayesian analysis. Prior information of the prevalence of Y. enterocolitica in faeces and the seroprevalence of Yersinia in serum of pigs collected at farms were obtained from previous studies and introduced in the models as beta prior informative distributions. Samples of intestinal content, tonsils, and swabs of carcasses and pluck set surfaces were collected at slaughterhouses. The posterior probabilities, odds ratio (OR) and their probability interval (PI) were calculated by means of a generalized linear model constructed in WinBugs. Occurrence of Y. enterocolitica in intestinal content (OR: 35.6, 95%PI 2.8–8285), tonsils (OR: 38.4, 95%PI 5.0–854), and pluck set (OR: 16.6, 95%PI 1.9–1111) was a risk for the contamination of pork carcasses, and an increased risk of contaminated pluck set was observed when Y. enterocolitica was isolated in intestinal content (OR: 40.6, 95%PI 2.1–10510) and tonsils (OR: 17.6, 95%PI 3.4–230.6). This increased risk indicated a potential cross-contamination at the slaughterhouse.

The Ewe's Reproductive Performance, Growth Rate and Carcass Quality of Lambs Kept in a Barn vs Those Kept under an Overhead Shelter.

A herd of polish lowland local sheep was divided into two equal groups: the first group was kept under an overhead shelter, and the second group was kept in a warm barn. The effect of maintenance on ewe’s reproductive performance, survival as well as the growth rate of lambs, and their carcasses quality was investigated. The lack of differences in fertility and prolificacy of ewes as well as in the survival and growth rate between the groups confirmed a good adaptation of Żelaźnieńska sheep to low temperature. Harsh environmental conditions did not cause a significant decrease of the body weight growth; however, they brought in an (insignificant) reduction of subcutaneous fat thickness and meatiness of the loin part of a lamb’s body. The fat content of carcasses obtained from lambs reared under the overhead shelter was significantly lower, with no differences of meat and bones contribution between the groups.

Growth performance, carcass characteristics and meat quality of growing rabbits housed in cages or open-air park

Abstract. The study was carried out to investigate the effects of two housing systems on the growth performance, carcass traits, and meat quality of growing rabbits during the terminal fattening period. The rabbits were lodged in conventional cages between 35 and 59 days of age (growing period). At this age, they were moved into two different housing systems until they were 87 days of age (fattening period). During the fattening period, 48 rabbits were housed in 12 wire cages (0.5×0.6×0.35 m) and 48 rabbits were housed in one open-air pasture pen (20×9 m). At 87 days, 12 rabbits per treatment were slaughtered and the carcass characteristics and meat quality were evaluated. During the fattening period, the rabbits reared in cages had significantly higher live weights (3 062 vs. 2 705 g), weight gains (45.9 vs. 34.2 g·d−1) and feed intakes (163.4 vs. 110.2 g·d−1) than those reared in pens. The rabbits in the open-air group had a lower percentage of dissectible fat (1.35 vs. 4.19 %), a higher proportion of hind part (34.9 vs. 33.1 %), and less hind leg muscle (79.3 vs. 81.9 %) than caged rabbits. The m. biceps femoris of the rabbits in the open-air group had a higher cooking loss (3.64 vs. 3.02 %), Warner-Bratzler Shear Force (4.26 vs. 3.29 kg·cm−2), and myoglobin concentration (0.41 vs. 0.32 mg·g−1) than caged rabbits. The housing system had no effect on the dressing out percentage, viscera proportion, and ultimate pH. Open-air housing system reduces the growth of rabbits and the fat content of carcasses and increases the redness colour of meat.

Effect of dietary choline on growth, intestinal enzyme activities and relative expressions of target of rapamycin and eIF4E-binding protein2 gene in muscle, hepatopancreas and intestine of juvenile Jian carp ( Cyprinus carpio var. Jian)

The effects of dietary choline on growth, digestive and absorptive capacities, and target of rapamycin (TOR) and eIF4E-binding protein2 (4E-BP2) gene expression in muscle, hepatopancreas and intestine of juvenile Jian carp ( Cyprinus carpio var. Jian) were assessed. A total of 1200 juvenile Jian carp with an average initial weight of 7.94 ± 0.03 g were fed six semi-purified diets containing 165 (unsupplemented control group), 310, 607, 896, 1167 and 1820 mg choline kg − 1 diet for 65 days. Specific growth rate (SGR), feed intake, feed efficiency, protein retention value, protein content and lipid content of fish carcasses were significantly improved by dietary choline supplementation; whereas, protein efficiency ratio and body ash content were not significantly different among dietary groups. Patterns of differences in intestine length, relative gut length, intestine weight, hepatopancreas protein content, intestinal folds height in three intestinal segments, trypsin and chymotrypsin activities in intestine and hepatopancreas, α-amylase and creatine kinase activities in intestine, Na +/K +-ATPase activity in distal intestine and relative expression of TOR gene in distal intestine and 4E-BP2 gene in muscle responded similar to SGR; whereas, the trends of hepatosomatic index, lipase activity in intestine and hepatopancreas, Na +/K +-ATPase activity in proximal intestine and mid intestine, TOR gene expression in muscle and hepatopancreas, and 4E-BP2 gene expression in proximal intestine, mid intestine and distal intestine were opposite. Alkaline phosphatase and γ-glutamyl transpeptidase activities in intestinal segments were not significantly different among dietary groups. These results indicated that dietary choline could improve fish growth, enhance digestive and absorptive ability and regulate TOR and 4E-BP2 gene expression in tissues. The dietary choline requirement of Jian carp estimated by the broken-line model based on SGR was 566 mg choline kg − 1 diet in the form of choline chloride.

Moisture content, processing yield, and surface color of broiler carcasses chilled by water, air, or evaporative air

This study was conducted to investigate the effects of water chilling (WC), air chilling (AC), and evaporative air chilling (EAC) on the moisture content, processing yield, surface color, and visual appearance of broiler carcasses. For the WC treatment, 1 group of birds was hard scalded and submersed into ice slush, whereas for AC, 1 group of birds was soft scalded and exposed to blowing air (1.0 m/s at 0°C) and for EAC, or 1 group of birds was soft scalded and exposed to blowing air and a cold water spray (every 5 min). During chilling, carcass temperature was reduced most effectively by WC (55 min), followed by EAC (120 min) and AC (155 min). After chilling, both WC and EAC carcasses picked up moisture at 4.6 and 1.0% of their weights, respectively, whereas AC carcasses lost 1.5% of their weight. On cutting at 5 h postmortem, WC carcasses showed the highest (2.5%), EAC showed the second highest (0.4%), and AC showed the least (0.3%) moisture loss. After 24 h of storage, almost 83% of the absorbed water in the WC carcass parts was released as purge, whereas EAC and AC carcasses maintained weights close to the prechilled weights. In an instrumental color evaluation and a visual evaluation by panelists, AC carcasses showed a darker appearance, a more yellow color, and more surface discoloration compared with WC or EAC carcasses.

Slaughter value, meat quality, creatine kinase activity and cortisol levels in the blood serum of growing-finishing pigs slaughtered immediately after transport and after a rest period

The experimental materials comprised 44 hybrid [female (Polish Large White x Polish Landrace) x male Duroc] growing-finishing pigs. The animals were randomly divided into two groups: 24 pigs were slaughtered immediately after transport and 20 pigs were slaughtered after a 24-hour rest period in the lairage. The meat content of pork carcasses, carcass dressing percentage, the proximate chemical composition, physicochemical and sensory properties of meat and shear force values were determined. Serum creatine kinase activity and cortisol levels were determined in blood samples collected before transport and during carcass bleeding. Pigs slaughtered immediately after transport, compared with those slaughtered after a 24-hour rest period, were characterized by a higher meat content of the carcass and a higher carcass dressing percentage. Pre-slaughter handling had no effect on pork quality. The incidence of normal-quality meat, partially PSE (pale, soft, exudative) meat and PSE meat was similar in both groups. Chemical analysis showed that the content of dry matter, total protein, fat and minerals in meat was comparable in both groups. As regards the functional properties of the pork, samples from the carcasses of pigs that had rested before slaughter had a higher contribution of the red color component. Meat from pigs slaughtered immediately after transport had more desirable sensory properties. Pre-slaughter resting had a significant effect on those analyzed physiological parameters which were found to be good indicators of pre-slaughter stress. Serum creatine kinase activity and cortisol levels were higher in blood samples collected after transport (during carcass bleeding) than in samples collected before transport, pointing to a strong stress response of animals to pre-slaughter treatment. The decrease in serum cortisol levels in blood samples collected during bleeding from the carcasses of pigs slaughtered after a 24-hour rest period, compared with samples collected from animals slaughtered immediately after transport, suggests that rest before slaughter alleviated stress induced by pre-slaughter handling operations.

Fattening Results of Finishing Pigs Fed Second-Stage Diets with a High Content of Oat Bran and Soybean Oil

The experiment was performed on 48 crossbred ( Polish Landrace x Duroc) finishing pigs divided into three feeding groups: group I (control) – fed a cereal-soybean diet (diet 1), group II – fed a diet containing 15% oat bran and 3% soybean oil (diet 2), group III – fed a diet containing 30% oat bran and 5% soybean oil (diet 3). The pigs were kept in straw-litter pens (two animals, one gilt and one barrow, in each), and they were fed ad libitum from 70 to 110 kg live weight. A second-stage diet containing 30% oat bran and 5% soybean oil (group III) significantly decreased average daily weight gains and feed conversion efficiency, compared with control group I and group II. Different feeding had no significant effect on the lean meat and fat content of carcasses and the proximate chemical composition of meat. Diet supplementation with oat bran and soybean oil contributed to a significant increase in alpha-linolenic acid concentrations in the lipids extracted from m. longissimus dorsi (m.l.d.). The higher content of crude fiber and crude fat in diets resulted in a highly significant increase in HDL concentrations and a significant increase in triacylglycerol levels in the blood serum of pigs, yet it had no influence on total cholesterol levels in meat (m.l.d.) and liver samples.

Physiological Stress as a Fundamental Mechanism Linking Predation to Ecosystem Functioning

We present a framework to explain how prey stress responses to predation can resolve context dependency in ecosystem properties and functions such as food chain length, secondary production, elemental stoichiometry, and cycling. We first describe the major nonspecific physiological stress mechanisms and their ecologically relevant consequences. We next synthesize the evidence for prey physiological responses to predation risk and demonstrate that they are similar across taxa and fit well within the general stress paradigm. We then illustrate the utility of our idea by applying our understanding of the ecological consequences of stress to explain how herbivore‐prey physiological antipredator responses affect ecosystem dynamics. We hypothesize that stressed herbivores should forage on plant species with higher digestible carbohydrates than should unstressed herbivores to meet heightened energy demands. Increased consumption of carbohydrate‐rich plants should reduce their relative abundance in the community, hence altering the quantity and quality of plant litter entering the detrital pool. We further hypothesize that stress should change the elemental composition and energy content of prey excreta, egesta, and carcasses that enter the detrital pool. Finally, prey stress should lower energy and nutrient conversion efficiency and hence the transfer of materials and energy up the food chain, which should, in turn, weaken the association between ecosystem productivity and food chain length.

Weight of selected muscles as an indicator of the lean meat and fat content of broiler carcasses (Short Communication)

Abstract. The objective of this study was to test whether the weight of selected arm and leg muscles and breast muscles may be used as an indicator of the content of lean meat and skin, including subcutaneous and abdominal fat, in the carcasses of broiler chickens. The experimental materials comprised 40 Ross 308 chicks aged 42 days (sex ratio 1 : 1). A total of 17 muscles were dissected from the right wing and the right leg. The right and left breast muscles were also dissected. Coefficients of simple correlation between the weight of individual muscles and selected slaughter quality parameters were calculated. The highest correlation was found between the lean meat content of a carcass and the weight of the right and left breast muscles (r=0.81 and 0.82 respectively), m. gastrocnemius mediale (r=0.81) and m. peroneus superficialis (r=0.73). The prediction of the weight of skin and fat in the carcasses of broilers based on the weight of single muscles may be unreliable due to low and non-significant values of correlation coefficients (r from 0.04 to 0.29). The weight of this tissue component was significantly correlated (r=0.42) with breast muscle weight only.