Daniel Bureš

Ageing is a key post-mortem process affecting beef quality; however, alternative fat-coating methods remain insufficiently understood. This study compared wet ageing (WA), dry ageing (DA), butter ageing (BA), and tallow ageing (TA) in terms of their effects on physicochemical, technological, and sensory characteristics. Longissimus lumborum muscles from Fleckvieh heifers were aged for 50 days under controlled conditions: WA samples were vacuum-packed, DA samples were stored bone-in, and BA and TA samples were coated with butter or rendered tallow. Instrumental quality analyses and descriptive sensory evaluation by a trained panel were performed. Ageing significantly improved tenderness in all treatments, reducing the Warner–Bratzler shear force (WBSF) from 55.8 N in fresh meat to 35.1–39.9 N after 50 days of ageing. However, tenderness did not differ significantly among the ageing methods. Meanwhile, pH increased and myofibrillar fragmentation progressed during ageing. The BA and TA samples exhibited higher scores for sour and atypical sensory notes. DA samples were also perceived as juicier than the other treatments. Overall, although all methods produced acceptable tenderness, conventional ageing, particularly dry ageing, provided superior sensory quality. Utilising butter or tallow coating during beef ageing did not enhance flavour development, and may negatively affect sensory profiles.

This exploratory study determined the ideal ageing period for optimum tenderness of Longissimus thoracis et lumborum (LTL), Semimembranosus (SM) and Biceps femoris (BF) steaks from male and female giraffe. The muscles of eight male and seven female giraffes were divided into 10 steaks each, and each steak was randomly allocated to age for 1, 5, 9, 14, 18, 22, 26, 30, 34 or 38 days in vacuum-sealed bags at ±4 °C. At each time point, the pH, surface colour, purge loss, cooking loss and Warner–Bratzler shear force (WBSF) were determined for the respective steaks. Significant interactions between the sex, muscle and days post mortem were observed for the Warner–Bratzler shear force (WBSF), CIE a*, CIE b*, hue-angle, and chroma, while the CIE L* values were affected by an interaction between muscle type and days post mortem. The pH showed three distinct phases: over Days 1–9, the pH (~5.54–5.55) was stable; over Days 14–22, it declined; and the pH dropped more sharply between Days 22 and 26 (~5.42 to ~5.32), before plateauing. The purge loss initially increased rapidly, after which the rate decreased during the ageing period; however, the cooking loss, which was affected only by muscle, remained constant throughout. The tenderness improved until Day 22 across all three muscle types (19.1 ± 0.30 N), after which it plateaued. The colour improved, in terms of redness and saturation, until Day 18 (L* = 44.1 ± 0.29; a* = 15.7 ± 0.19; b* = 15.3 ± 0.08; hue-angle = 44.8 ± 0.39; chroma = 22.0 ± 0.15); thereafter, discolouration occurred. Vacuum-ageing giraffe meat for 14–22 days is recommended to improve tenderness and colour and minimise the negative effects of increased purge loss. This recommendation is based on instrumental measurements with discolouration as a major determinant of acceptability. It is suggested that future research validate this through sensory evaluation and microbial analyses.

The aim of the study was to investigate the incorporation of white (WL) and yellow lupine (YL) seed meal as a replacement for rapeseed meal (RS) in the diets of finishing bulls with respect to growth, serum biochemical parameters, carcass composition and meat quality, including sensory analysis. A total of 30 Fleckvieh bulls (average initial weight 441 kg; SD = 33 kg) were housed under identical conditions and fed ad libitum diets similar in protein and energy contents, but with different protein sources—YL seed meal (70 g/kg DM), WL seed meal (77 g/kg DM), and RS meal (75 g/kg DM)—for an average of 85 days. The RS bulls gained weight more rapidly (p < 0.05) and were more efficient (lower feed to gain ratio; p < 0.001) than the YL animals, with the WL group being intermediary. The slaughter and carcass traits, most blood parameters, and meat quality attributes measured in two different muscles were not affected by diet. The proportions and contents of saturated and monounsaturated fatty acids were higher in YL and WL meat (p < 0.001), whilst polyunsaturated fatty acid proportions were higher in RS meat (p < 0.001). Several meat texture characteristics were slightly more favourable in the YL samples compared to the other treatment groups. In conclusion, WL could be used as a replacement of RS in the diets for finishing bulls. However, further research is needed to examine different varieties and inclusion levels of YL in cattle feeding.

The utilisation of game meat contributes towards various Sustainable Development Goals; however, it is necessary to quantify and optimise game meat quality for the commercial market to ensure high and uniform product quality to ensure consumer satisfaction. Understanding the factors that impact game meat quality, like muscle fibre composition, can provide insight into the expected meat quality of certain game species and subsequently determine appropriate processing and cooking techniques. Therefore, the aim of the study was to compare the muscle fibre characteristics of two farmed game species and cattle. Cattle (Bos Taurus; n = 10), common eland (Tragelaphus oryx; n = 10), and fallow deer (Dama dama; n = 10) were slaughtered at approximately 18 months of age. The samples of the longissimus thoracis et lumborum (LTL), triceps brachii (TB), and rectus abdominis (RA) muscles were analysed for muscle fibre composition. Cattle muscles had larger cross-sectional areas for all muscle fibre types within all muscles compared to the common eland and fallow deer muscles. The LTL of the fallow deer and eland muscles showed lower proportions of type I and higher proportions of type IIA fibres than cattle. Moreover, the proportion of type I fibres was lower in the LTL of fallow deer and eland compared to other muscles, differences that were not observed in cattle. These results may be an important indicator of changes in muscle mass that could occur in these farmed species as a result of future breeding selection.

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.

In Africa, offal is a cheap source of protein and is regularly consumed. The yields and proximate analyses of 15 giraffe (eight male, seven female) were evaluated. The only significant differences of offal weights between sexes were for the head with tongue (P = 0.011), feet (P = 0.006), and kidneys (P = 0.045), with each being heavier for males than females. However, as a percentage of the total dead weight, there were no significant differences between sexes. The study also looked at the proximate composition of the heart, liver, kidneys, and tongue. The moisture % averaged ∼76%, protein % averaged ∼17%, total fat % averaged ∼5% and the ash % averaged ∼1% for all organs across both sexes. While sex only had an effect on the ash content (P = 0.038), organ type had an effect on all parameters (P < 0.001). Red offal had a favourably high protein content as well as a low fat content, which, when combined with the high yields thereof per animal, indicates that giraffe offal can serve as a source of low-cost protein.

Forty-four fallow deer bucks (10 months old; 22.9 ± 2.4 kg) were utilized to investigate the effects of immunocastration and amino acid supplementation on testes development. Immunocastrated bucks were administered Improvac^® at weeks 1, 8, and 20 of this study (control group: intact males). Starting at week 8, half of each sex received rumen-protected lysine and methionine (3:1) supplementation. At slaughter (week 37/39), body size, internal fat deposits, antler size parameters, testes weight, testes surface color, cauda epididymal sperm viability and morphology, and seminiferous tubule circumference and epithelium thickness were determined. Animals with larger body sizes, greater forequarter development, and antler growth also had greater testes development. Whilst the result of immunocastration on testes size is unexpected, testes tissue showed impaired development (atrophied seminiferous tubules), decreased sperm viability, and normal morphology. Testes tissue from immunocastrated deer was less red, possibly indicating reduced blood supply. Conversely, amino acid supplementation increased testes’ redness and sperm viability, and intact males fed amino acids showed the greatest seminiferous tubule development. Thus, immunocastration may be a welfare-friendly alternative for venison production. Whilst the results support findings from the literature that testes size is not a reliable indicator of immunocastration success, this warrants further investigation in deer over different physiological development stages.