Effect of Pre-Slaughter Practises and Early Post-Mortem Interventions on Sheep Meat Tenderness and Its Impact on Microbial Status

Tenderness, together with flavour, is the main quality trait that defines consumer acceptance of sheep meat. The factors affecting tenderness can be grouped as those influenced before slaughter, in the early post-mortem intervention and, finally, during the aging period. These factors have been extensively studied with respect to tenderness, but the impact of early post-mortem interventions and subsequent aging on the microbial quality of the final products has not been broadly reviewed to date. In this review, the authors summarize the most recent knowledge on lamb meat tenderness management and how such practices may impact the final meat quality, especially its microbial status. The impacts of pre-slaughter factors (age, sex, diet, genotype and transport) and post-mortem interventions (chilling regime, electrical stimulation, or hanging method), are described and comprehensively discussed.

Metabolomics of meat color: Practical implications

Objective: Meat is biochemically active, and the various pre-and post-harvest processes can affect meat quality. Metabolomics is a valuable tool to elucidate metabolite changes in meat. The overall goal of this study was to provide an overview of various techniques, data analysis, and application of metabolomics in meat color research. Results: Both targeted and non-targeted approaches have been used to determine metabolite profiles in meat. Researchers use gas-, liquid-chromatography, and nuclear magnetic resonance platforms to separate molecules. Metabolomics is used to characterize muscle-specific differences in color stability, meat tenderness, the impact of aging on meat color, and to determine metabolite profile differences between normal-pH and dark-cutting beef. Color stable muscles have more glycolytic metabolites than color labile muscles. Conclusion: The use of metabolomics has greatly enhanced our understanding of metabolites' role in meat quality. There are challenges in data analysis; thus, there is a need for multiple platforms in order to obtain comprehensive metabolite libraries specific to food. Metabolomics in combination with wet-laboratory techniques can provide novel insights on the relationship between postmortem metabolism and meat color.

Genes and proteins associated with ribeye area and meat tenderness in a commercial Nellore cattle population

Despite several studies on genetic markers and differently expressed genes related to ribeye area (REA) and tenderness traits in beef cattle, there is divergence in the results regarding the genes associated with these traits. Thirteen genes that had been associated or have biological functions that may influence such phenotypes were included in this study. A total of five genes for REA (IGF-1, IGF-2, MSTN, NEDD4, and UBE4A) and eight genes for meat tenderness (CAPN1, CAPN2, CAST, HSPB1, DNAJA1, FABP4, SCD, and PRKAG3) were selected from previously studies in beef cattle. Genes and its respective proteins expression were validated in a commercial population of Nellore cattle using quantitative real-time PCR (RT-qPCR) and advanced mass spectrometry (LC / MS-MS) techniques, respectively. MSTN gene was upregulated in animals with low REA. CAPN1, CAPN2, CAST, HSPB1, and DNAJA1 genes were upregulated in animals with tougher meat. The proteins translated by these genes were not differentially expressed. Our results could confirm the potential of some studied genes as biomarkers for carcass and meat quality in Nellore cattle.

Chemical, Physical And Oxidative Characteristics Of Broilers Meat Supplemented With Passion Fruit Seed Oil

Residues that could be discarded and transformed in high biological value protein is a measure of environmental preservation combined with the sustainability of animal production. This study evaluated the effects of the addition of passion fruit seed oil (PFSO) on broiler diet under the resistance of skin, physical-chemical characteristic, fatty acid profile and lipid oxidation (under storage) of breast meat obtained from these animals. There was improvement in the condition of skin rupture and meat tenderness; apart from that, oxidative reactions decreased, as PFSO was added to the diet (P<0.05). On the other hand, no effect on colour, pH, water retention capacity and weight loss on cooking (P>0.05) was observed. There was a linear effect increasing only for the margaric (C17:0) and cis10-Heptadecanoic (C17:1; P<0,05) fatty acids. However, due to the low amount of these fatty acids in PFSO, the found content was still low in all evaluated treatments. However, the evaluated levels did not contribute to the increase of the polyunsaturated fatty acid profile (P>0.05). Thus, it can be concluded that PFSO improves the resistance of broiler skin, which becomes softer and less susceptible to oxidative effects due to the oil’s antioxidant action, suggesting that it may be an ingredient that brings substantial benefits in the poultry industry.

Response to iodine supplementation in the growth and quality of Texel lamb meat

Iodine deficiency determines reproductive problems especially in the production of thyroid hormone, affecting the functions that thyroidal hormones regulate, such as energy metabolism, thermoregulation, reproduction, growth, muscle and bone tissue function. Indeed a certain concentration of iodine in the diet can promote performance in production in terms of fattening and growth. The main goal of the work was the supplementation with iodine salt from weaning to work on the production and quality of carcass and meat of early lambs of the Texel breed. Three random groups were formed. In one group, iodine salt was administered daily individually, in another group salt without iodine and finally a third "control" group without salt aggregate. All these animals were fed on natural field with an energy-protein supplement. The weaning weight and its evolution (daily gain) were determined, fortnightly until the work weight (35 kg) was reached. Blood levels of thyroid-stimulating hormone (TSH) and Selenium (Se) were evaluated. In the carcass were measured the hot and cold carcass weight, pH, colour; GR point and in the meat tenderness will be determined in the Longissimus dorsi muscle. Se concentrations, neutral detergent fiber, crude protein and iodine in pastures were also determined. The results show that no significant differences were found for any of the characters measured.

Southern African Large Frame Indigenous Veld Goat and Boer Goat Wether and Buck Tenderness and Colour of Six Muscles

Meat tenderness, water holding capacity (WHC) and colour attributes of six muscles (Longissimus thoracis et lumborum (LTL), Semimembranosus (SM), Biceps femoris (BF), Supraspinatus (SS), Infraspinatus (IS), Semitendinosus (ST)) from large frame Indigenous Veld Goats (IVG) and Boer Goats (BG) were studied. Weaner male Boer Goats (BG; n = 18; 10 bucks and 8 wethers) and large frame Indigenous Veld Goats (IVG; n = 19; 9 bucks and 10 wethers) were raised on hay and natural grass, and on a commercial pelleted diet to a live weight of 30 - 35 kg. All goats were slaughtered at a commercial abattoir and the dressed carcasses chilled at 4&deg;C within 1-hour post-mortem. The muscles were dissected from both sides 24-hours post-mortem and aged for 1-day and 4-days. Variations in meat characteristics such as ultimate pH, WHC, percentage purge, myofibril fragment length, intramuscular fat, connective tissue characteristics, and Warner-Bratzler shear force. Bucks had higher L* and Hue-angle values, whereas wethers had increased a* and Chroma values. The muscle baseline-data will allow informed decisions to support muscle-specific marketing strategies, which may be used to improve consumer acceptability of chevon.

Frame Score, Grazing and Delayed Feedlot Entry Effect on Performance and Economics of Beef Steers from Small- and Large-Framed Cows in an Integrated Crop-Livestock System

When selling small-framed steers at weaning, profitability is diminished. The hypothesis is that by using a vertically integrated business model that includes retained ownership, extended grazing, abbreviated feedlot finishing, and selling at slaughter, profitability would increase. Crossbred yearling steers (n = 288) from small size Aberdeen Angus (Lowline) × Red Angus × Angus × Angus cows and moderate to large size Red Angus × Angus × Simmental × Gelbvieh cows calved May−June were randomly assigned (complete randomized design), in a 3 y study, to feedlot control (FLT) and extended grazing (GRZ) frame score treatment groups. Mean frame score for FLT were small frame (SF) 3.82 and large frame (LF) 5.63, and for GRZ, SF: 3.77 and LF: 5.53. Least-square means were utilized to identify levels of effects and to control family-wise error adjusted with Tukey test. The FLT control steers were housed in the feedlot and fed growing diets and subsequently high energy corn-based diets for 218 days. The GRZ steers grazed a sequence of forages (native range, field pea-barley mix, and unharvested corn) for 212 days and then were transferred to the feedlot and fed high energy corn-based finishing diets for 82 days. The SF GRZ steers grew more slowly grazing native range and annual forages compared to GRZ LF steers, but SF steer grazing cost per kg of gain was reduced 7.80%. Grazing steers did not grow to their full genetic potential. Slower growth during grazing allowed LF and SF steers to grow structurally before feedlot entry creating a compensatory feedlot finishing growth response. Overall, grazing steer performance exceeded steer performance of the FLT control treatment and LF grazing steers had the highest rate of gain, and lowest feed cost per kg of gain. The GRZ steer feedlot days on feed were reduced 136 days and total feed intake was reduced resulting in LF and SF grazing steer feed cost reductions of 175.9 and 165.3%, respectively. Extended grazing also resulted in LF and SF grazing steer hot carcass weights to be greater than control LF and SF steers and SF grazing steers had greater dressing percent, and marbling score. Carcass quality grade, meat tenderness, and cooking losses were similar. System net returns were highest for LF (USD 911.58), and SF (USD 866.61) grazing steers. Managerial modification combining retained ownership, extended grazing, and delayed feedlot entry increased profitability and eliminated market bias.