The Sarcoplasmic Protein Profile of Breast Muscle in Turkeys in Response to Different Dietary Ratios of Limiting Amino Acids and Clostridium perfringens-Induced Inflammation

In this study, the effects of the Arginine/Lysine (Arg/Lys) ratio in low- and high-methionine (Met) diets on the sarcoplasmic protein profile of breast muscles from turkeys reared under optimal or challenge (Clostridium perfringens infection) conditions were determined. One-day-old Hybrid Converter female turkey poults (216 in total) obtained from a commercial hatchery on hatching day, and on the basis of their average initial body weight were randomly allocated to 12 pens (4 m² each; 2.0 m × 2.0 m) containing litter bedding and were reared over a 42-day experimental period. Diets with high levels of Lys contained approximately 1.80% and 1.65% Lys and were offered in two successive feeding periods (days 1–28 and days 29–42). The supplemental levels of Lys were consistent with the nutritional specifications for birds at their respective ages as established in the Management Guidelines for Raising Commercial Turkeys. The experiment was based on a completely randomized 3 × 2 × 2 factorial design with three levels of Arg (90%, 100% and 110%) relative to the content of dietary Met (30 or 45%) and without (−) or with (+) C. perfringens challenge at 34, 36, or 37 d of age. Meat samples were investigated in terms of pH, color, and sarcoplasmic protein profile. The experimental factors did not influence meat quality but the dietary Arg content affected meat color. The sarcoplasmic protein profile was influenced by all studied factors, and glycolytic enzymes were the most abundant. This study evidenced strong association between the challenge conditions and the involvement of glycolytic enzymes in cell metabolism, particularly in inflammatory processes, and DNA replication and maintenance in turkeys. The results showed an effect of C. perfringens infection and feeding with different doses of Arg and Met may lead to significant consequences in cell metabolism.

Proximate Composition, Amino Acid Profile, and Mineral Content of Four Sheep Meats Reared Extensively in Morocco: A Comparative Study

This study aimed to compare the organoleptic and nutritional quality of four sheep meats produced in Morocco. This comparison was carried out by analyzing the proximate composition, amino acid profile, and mineral content of meat. The majority of the evaluated parameters were influenced by genetic and geographical factors (p < 0.05). The longissimus lumborum muscle had higher a^∗ value in Timahdite and Ouled-Djellal breeds. The highest values of macroelement were recorded in samples of Beni-Guil meat sampled in the Tendrera region (BGT; 1067.3 mg/100 g), while the highest microelement content was registered in Timahdite meat (5.7 mg/100 g). Iron and zinc were the major identified trace elements, while phosphorus and potassium were the most abundant macroelements. The abundant amino acid was glutamic, while cysteine and methionine were least abundant. The higher essential amino acids index (IEAA) was recorded in the Timahdite sheep meat (162.20, 158.71, 161.02, and 159.65, respectively, for Timahdite, BGT, Ouled-Djellal breeds, and Beni-Guil meat sampled in Ain Beni Mathar region). From a nutritional point of view, the studied meats had a good protein and mineral quality, due to their richness in essential amino acids and microelements. The present study provided new insights on the organoleptic quality and the nutritional value of three Moroccan sheep meats reared in outdoor production system.

Quality, nutrient and sensory characteristics of aged meat from lambs supplemented with selenomethionine

Selenium (Se) as a co-factor of antioxidant enzymes is metabolically essential for animals. Its presence in muscle can improve the oxidative stability of meat and is a desirable nutrient for consumers. A novel approach to Se supplementation for meat-producing livestock was demonstrated in a 95-day study of young lambs. DL-selenomethionine (SeMet) was administered by subcutaneous injection at day 0 (3-4 weeks of age) and again at day 54. A Control group (n = 9) received carrier only, whilst Medium and High groups (n = 10) received graded levels of Se. Physicochemical attributes of meat quality and sensory characteristics were measured at 1, 3, 14 and 42 days of ageing (vacuum packaged at -1.5 °C), followed by instrumental colour measurements after 7 days of simulated retail display. There were no significant interactions between SeMet treatment and ageing. Muscle pH, drip and cooking losses, initial display colour and sensory evaluations by trained and consumer panels were unaffected by treatment. Smaller changes in colour during display were observed for the Medium group compared to Control (P < 0.05). The shorter range of ageing times improved meat tenderness however extended ageing decreased colour stability. SeMet markedly increased Se concentrations in muscle, blood, kidney and liver (P < 0.05), resulting in Se enriched meat without appreciable changes in meat quality.

Seleno-compounds and Carnosic Acid Added to Diets with Rapeseed and Fish Oils Affect Concentrations of Selected Elements and Chemical Composition in the Liver, Heart and Muscles of Lambs

The objective of our studies was to investigate effects of carnosic acid (CA), selenized yeast (SeY) and selenate (SeVI) added to the diet including rapeseed oil (RO) and fish oil (FO) on concentrations of elements, fatty acids (FAs), tocopherols, cholesterol, and malondialdehyde in the liver, heart, musculus longissimus dorsi (MLD), and musculus biceps femoris (MBF) of lambs. Lambs were fed diets: group I-the basal diet (BD) with RO; group II-BD with RO and FO; group III-BD with RO, FO, and CA; group IV-BD with RO, FO, CA, and SeY; group V-BD with RO, FO, CA, and SeVI. The diets with Se compounds increased Se concentrations in all tissues compared with other diets. The diet with SeVI increased Cd, Sb, and Pb concentrations in the liver compared to groups I, II, and IV. The diets containing Se compounds increased Sb and Pb concentrations in MBF compared to groups I and II. All diets with CA reduced As, Sb, and Pb concentrations in MLD compared to groups I and II. All diets with FO increased concentrations of FAs and malondialdehyde in the liver compared to group I. All diets with FO decreased FAs concentrations in MBF compared to group I. The diets containing CA with/without Se compounds increased malondialdehyde concentrations in MBF compared to groups I and II. The diet with Se compounds reduced malondialdehyde concentrations in MLD compared to group II. All diets with FO changed concentrations of tocopherols and cholesterol in all tissues compared to group I. Our study showed that the addition of SeY or SeVI to the experimental diet increased the concentration of Se in all assayed tissues of lambs without adversely influencing performance or causing physiological disorders in internal organs. Both, SeY or SeVI added to the experimental diet decreased the oxidative stress and the concentrations of As, Sb, and Pb in MLD compared with the diets containing RO, irrespective of the presence of FO (groups I and II). Our study provides useful knowledge for nutritionists carrying out further investigations aimed at improving farm animal health, performance, and the nutritional quality of animal products for humans.