Sex influence on muscle yield and physiochemical characteristics of common eland (Taurotragus oryx) meat

Consumer acceptance and quality of game meat "droëwors" sausages with different levels of added fat

Droëwors (dried sausage) is a unique dried meat product from South Africa, which is not smoked, fermented, nor is nitrite used in its production. The objective of the study was to compare the quality parameters and consumer acceptance of common eland meat droëwors with different quantities of added beef fat. Three treatments containing either 10, 15, or 20% (by weight) added beef fat were compared regarding chemical composition, fatty acid profiles, and sensory properties. Increasing the amount of fat in the dried product resulted in a significant decrease in the protein and ash percentages. The sausages with 10% added fat had the most favourable fatty acid profile in terms of nutritional value. Several differences were found in the sensory profiles of the products evaluated by the trained sensory panel; in particular, the evaluation scores for texture improved with increasing fat content. No differences were found between the products by the untrained consumer panel for appearance and taste. When the dataset was analysed according to gender, it was found that women evaluated the 10% fat samples more favourably. This is in line with their stated preference for low-fat meat products. For these reasons, the production of sausages with the lowest fat content can be recommended as they best meet consumer expectations.

The Effect of Sex on the Chemical and Mineral Composition of the Meat, Bone and Liver of Giraffe (Giraffa giraffa angolensis)

Consumers tend to buy meat based on visual physical characteristics, which are affected by the chemical composition of the meat, and there is very little known about the chemical composition of the meat of giraffe. This study therefore aims to broaden the knowledge base on the chemical composition of giraffe meat, rib bone and liver. Eight different muscles from 15 giraffes were analyzed to determine the chemical composition, yielding an average moisture of 77.2 ± 0.09 g/100 g meat, an average protein of 20.8 ± 0.09 g/100 g meat, an average intramuscular fat (IMF) of 1.4 ± 0.03 g/100 g meat and an average ash of 1.1 ± 0.01 g/100 g meat. There was a significant interaction between sex and muscle for the moisture, protein and ash contents, while only muscle had an effect on the fat content. The mineral content of the bone, liver and Longissimus thoracis et lumborum muscle was also analyzed, and bone was found to be a rich source of calcium (highest concentration), whilst the liver had the highest concentration of iron. The chemical composition of the giraffe meat was such that it could be classified as lean meat.

Low rumen degradable starch promotes the growth performance of goats by increasing protein synthesis in skeletal muscle via the AMPK-mTOR pathway

Since starch digestion in the small intestine provides more energy than digestion in the rumen of ruminants, reducing dietary rumen degradable starch (RDS) content is beneficial for improving energy utilization of starch in ruminants. The present study tested whether the reduction of rumen degradable starch by restricting dietary corn processing for growing goats could improve growth performance, and further investigated the possible underlying mechanism. In this study, twenty-four 12-wk-old goats were selected and randomly allocated to receive either a high RDS diet (HRDS, crushed corn-based concentrate, the mean of particle sizes of corn grain = 1.64 mm, n = 12) or a low RDS diet (LRDS, non-processed corn-based concentrate, the mean of particle sizes of corn grain >8 mm, n = 12). Growth performance, carcass traits, plasma biochemical indices, gene expression of glucose and amino acid transporters, and protein expression of the AMPK-mTOR pathway were measured. Compared to the HRDS, LRDS tended to increase the average daily gain (ADG, P = 0.054) and decreased the feed-to-gain ratio (F/G, P < 0.05). Furthermore, LRDS increased the net lean tissue rate (P < 0.01), protein content (P < 0.05) and total free amino acids (P < 0.05) in the biceps femoris (BF) muscle of goats. LRDS increased the glucose concentration (P < 0.01), but reduced total amino acid concentration (P < 0.05) and tended to reduce blood urea nitrogen (BUN) concentration (P = 0.062) in plasma of goats. The mRNA expression of insulin receptors (INSR), glucose transporter 4 (GLUT4), L-type amino acid transporter 1 (LAT1) and 4F2 heavy chain (4F2hc) in BF muscle, and sodium-glucose cotransporters 1 (SGLT1) and glucose transporter 2 (GLUT2) in the small intestine were significantly increased (P < 0.05) in LRDS goats. LRDS also led to marked activation of p70-S6 kinase (S6K) (P < 0.05), but lower activation of AMP-activated protein kinase (AMPK) (P < 0.05) and eukaryotic initiation factor 2α (P < 0.01). Our findings suggested that reducing the content of dietary RDS enhanced postruminal starch digestion and increased plasma glucose, thereby improving amino acid utilization and promoting protein synthesis in the skeletal muscle of goats via the AMPK-mTOR pathway. These changes may contribute to improvement in growth performance and carcass traits in LRDS goats.

A Descriptive Study on the Carcass, Muscle, and Offal Yields of the Plains Zebra (Equus quagga) Harvested in Two Seasons

This study presents descriptive data on the meat and offal production of Plains zebras harvested in the winter (n = 8) and summer (n = 12) seasons, at different respective locations in the Western Cape Province of South Africa. The cold dressing percentages were numerically higher for the winter (58.0 ± 0.60%) than for the summer-harvested animals (56.60 ± 0.70%). Heavier internal offal yields were reported for the winter-harvested group (70.76 ± 21.8 kg) compared to the summer-harvested animals (66.13 ± 3.78 kg). As harvest season had no influence, pooled data of the percentage contribution of each muscle to cold carcass weight indicated that the Longissimus et lumborum (3.5 ± 0.18%), semimembranosus (1.6 ± 0.04%), biceps femoris (2.7 ± 0.05%) and semitendinosus (0.9 ± 0.02%) muscles differed significantly in their respective contributions to cold carcass weight. No significant differences were recorded between the contribution of the infraspinatus (0.6 ± 0.02%), supraspinatus (0.4 ± 0.03%) and psoas major (0.6 ± 0.02%) muscles. Carcass and muscle yields, as well as low-cost protein offal yields from this study indicate that the Plains zebra has the potential to be used and distributed as an alternative protein source.

Carcass and Offal Yields of Farmed Common Eland (Taurotragus oryx) Males, as Affected by Age and Immunocastration

This study investigated the effects of immunocastration and slaughter age on the carcass yield performance of intensively farmed common eland males. Eighteen male eland (five immunocastrated juveniles, three intact juveniles, five immunocastrated sub-adults, and five intact sub-adults) were finished for four months, after which their carcass, offal, primal cut, and individual muscle yields were determined. Juveniles were ~6 months of age at the start of the experiment, while sub-adults were ~1.5 years old. Primal cuts were dissected to determine the percentage yields of meat, bones (with tendons), separable fat, and trimmings. Immunocastration had no effect on offal or carcass yields. While sub-adults had increased individual muscle yields, juveniles had greater proportionate yields of primal cuts and a greater total high-value: low-value meat ratio. Whilst slaughtering younger male eland could provide additional economic advantages, this should be considered being against changing marketing trends.

Physical meat quality characteristics of Angolan giraffe (Giraffa giraffa angolensis) as affected by sex and muscle

Giraffe numbers grow exponentially when farmed, necessitating periodic culling. This study quantified the effect of sex and muscle on the physical quality characteristics of eight giraffe muscles. The Warner-Bratzler shear force (WBSF) was the only parameter to be affected by an interaction between sex and muscle (P < 0.001), although the interaction for the CIE L* values tended towards significance (P = 0.054). Cooking loss (male = 41.6 ± 0.35%; female = 40.7 ± 0.33%; P = 0.024) and CIE L* values (male = 38.8 ± 0.23; female = 37.3 ± 0.27; P = 0.039) were both affected by sex. Muscle had an effect on all physical parameters. The ultimate pH of all muscles was 5.5-5.9; the average WBSF of <43 N for all muscles indicates giraffe meat in this study is tender. This study shows that yield and physical characteristics of giraffe meat are favourable, and the results may be useful for the marketing of giraffe meat.

The Effect of Barley and Lysine Supplementation on the longissimus lumborum Meat Quality of Pasture-Raised Fallow Deer (Dama dama)

The chemical characteristics (proximate composition, amino acids, and fatty acids) and sensory quality of the longissimus lumborum (LL) muscle of 45 farmed male fallow deer were investigated. The animals were divided into three separate groups (n = 15 per treatment): pasture-fed (P), pasture-fed and supplemented with barley (B), and pasture-fed and supplemented with barley and lysine (BL). Differences were observed in LL moisture and the intramuscular fat contents, the latter being almost two-fold greater in the meat of B and BL groups compared to P. The concentrations of histidine, leucine, alanine, glutamic acid and glycine in the raw meat were higher in the BL group compared to the P group. Higher contents of n–3 polyunsaturated fatty acids (PUFAs), and consequently lower n–3 ratios, were found in the P group, compared to the BL group. The grilled meat samples from the P group scored higher than the other groups for grassy flavour, and lower for liver flavour.

Physical Changes during Post-Mortem Ageing of High-Value Impala (Aepyceros Melampus) Steaks

Antelope meat production is rapidly growing, not only due to their adaptation to marginal land usage, but also because of its favorable nutritional properties and free-range production. However, limited information is available on the meat quality and processing potential of game meat for commercial consumption. The objective of this study was to determine the ageing period to achieve maximum tenderness of longissimus thoracis et lumborum (LTL) muscles of impala. The LTL muscles of 11 male and 11 female impala were harvested, and divided into eight portions. Each portion was randomly allocated to 1, 2, 4, 6, 8, 10, 12, or 14 days of wet-ageing (4 °C) in vacuum packaging. The meat pH, color, weep loss, cooking loss, and Warner–Bratzler shear force were measured throughout ageing. Initially the ageing profile differed depending on the sex of the animal from which the muscle was harvested; however, after 8 days of ageing, maximum tenderness was reached (13.5 ± 0.91 N) and no further sex differences were seen. Ageing improved the surface color of all meat until day 8, after which discoloration occurred. Therefore, it is recommended that impala LTL steaks should be wet-aged at 4 °C for eight days to achieve maximum tenderness and minimize sex variability.

Carcass yields and physiochemical meat quality characteristics of Namibian gemsbok (Oryx gazella) as influenced by muscle, gender and age

The carcass yields and physiochemical meat quality characteristics of six different muscles (biceps femoris, infraspinatus, longissimus thoracis et lumborum, semimembranosus, semitendinosus, supraspinatus) for different sex and age groups of gemsbok antelope were determined. No live weight nor dressing percentage differences were observed for the different sex groups. While muscles, age and sex had an influence on the physiochemical parameters investigated, these differences were minor. The CIE Lab colour values for all muscles, age and sexes were in line with those deemed acceptable for game meat, while mean crude protein (20.7%) and fat (1.6%) levels were typical of game species. Discriminant analysis revealed no differentiation among the muscle groups for the variables measured. Thus, at similar live weights, male and female (sub-adult) gemsbok can be considered of equivalent meat quality and marketed accordingly.

Ante-and post-mortem strategies to improve the meat quality of high-value muscles harvested from farmed male common eland (Taurotragus oryx)

The effects of immunocastration, pelvic suspension and wet ageing on the meat quality of the longissimus lumborum et thoracis (LTL) and biceps femoris (BF) muscles of male common eland were evaluated. Ten subadult males were either immunocastrated (n = 5) or remained intact (n = 5) throughout a four-month growth trial, after which their carcass sides were randomly allocated to either pelvic- or Achilles-suspension. The LTL and BF were further aged for 14 days, measuring changes in the physical quality weekly. The sensory quality of the LTL and BF were determined after ageing (8/9 days, respectively). Immunocastration had minimal effects on the meat quality of male eland, but pelvic suspension decreased the shear force. All muscles reached minimum shear force after seven days of ageing, and the panellists ranked the pelvic-suspended muscles higher for tenderness traits. Incorporating pelvic suspension and wet ageing into the commercial processing of eland carcasses should be considered to improve overall meat quality.

Chemical Composition of Wild Fallow Deer (Dama Dama) Meat from South Africa: A Preliminary Evaluation

Although fallow deer are abundant in South Africa, these cervids remain undervalued as a domestic protein source and little information exists on their meat quality. This study aimed to evaluate the proximate and mineral compositions of the meat from wild fallow deer (n = 6 male, n = 6 female) harvested in South Africa, as affected by sex and muscle. Proximate analyses were conducted on six muscles (longissimus thoracis et lumborum [LTL], biceps femoris [BF], semimembranosus [SM], semitendinosus [ST], infraspinatus [IS], supraspinatus [SS]), whereas mineral analyses were conducted on the LTL and BF. The proximate composition of the muscles ranged from 73.3-76.2% moisture, 20.4-23.1% protein, 2.2-3.2% fat, and 1.1-1.5% ash. Proximate composition was significantly (p ≤ 0.05) influenced by muscle, but not by sex. The primary essential macro- and micro-minerals determined in the LTL and BF were potassium, phosphorus, sodium, and magnesium, as well as iron, zinc, and copper, with more variation in concentrations occurring with muscle than with sex. Minerals in the muscles contributing most notably to human recommended dietary requirements were potassium, iron, copper, and zinc. These findings indicate that wild fallow deer meat is a nutritious food source and should enhance utilisation of such products.

Carcass Yields and Physiochemical Meat Quality of Semi-extensive and Intensively Farmed Impala (Aepyceros melampus)

The effects of sex and production systems on carcass yield, meat quality and proximate composition of sub-adult impala were evaluated by culling 35 impala from intensive (12 males) and semi-extensive (12 males and 11 females) production systems within the same game farm. While no sexual dimorphism was found for carcass weights, male impala had a higher dressing percentage than females, indicating a higher meat production potential. Few differences were observed for yields between the male impala from the different production systems, but physical meat quality parameters indicated possible stress for those kept intensively. Minor differences existed in physiochemical parameters between various impala muscles for the two sexes and production systems, providing little motivation for these factors to be considered when processing sub-adult impala carcasses. Impala meat from both sexes, all muscles and all production systems produced meat with shear force values below 43 N, and thus may be considered as tender. Furthermore, the proximate composition of all impala meat in this study ranged from 74.7 to 77.0 g/100g moisture, 20.7 to 23.5 g/100g protein, 1.2 to 2.2 g/100g fat and 1.1 to 1.3 g/100g ash content. These values compare favorably to other game species, indicating that impala meat may serve as a lean protein source.