Liesel L. Laubscher

Meat quality of kudu (Tragelaphus strepsiceros) and impala (Aepyceros melampus): Carcass yield, physical quality and chemical composition of kudu and impala Longissimus dorsi muscle as affected by gender and age

The meat quality of kudu and impala was compared. Live weight and carcass weight differed between species, genders and age groups. Impala had the highest dressing percentage while kudu had the highest live weight and carcass weight. Kudu had the lowest fat content while female animals had a higher fat and myoglobin content than males. Sub-adults had a higher ash content than adults. Species, gender and age had no effect of pH, drip loss, cooking loss or tenderness although kudu had higher L∗, a∗, b∗ and chroma values than impala. Impala sub-adults had significantly higher insoluble collagen, soluble collagen, total collagen and hydroxyproline content than kudu sub-adults. Kudu had the highest potassium levels while impala had the highest phosphorus levels. Potassium, sodium, iron and copper levels also differed between species.

Nutritional value of cooked offal derived from free-range rams reared in South Africa.

Nutritional value of Dorper (n=10) and Merino (n=10) by-products were evaluated. Proximate composition differed between organs and breeds with Merino heart (68.9 g/100 g), spleen (77.2 g/100 g) and testicles (83.7 g/100 g) having higher moisture contents than their Dorper counterparts. Dorper brain (10.1 g/100 g), heart (15.2 g/100 g), spleen (20.4 g/100 g) and testicles (12.9 g/100 g) had higher protein contents than Merino. Dorper organs also tended to have a lower fat content. Amino acid and fatty acid profiles differed between organs and breeds. Few differences were noted in total SFA and MUFA. Dorper heart (1.8%) had significantly lower total PUFA than Merino heart (7.3%). All the organs showed favourable P:S ratios, with the exception of the tongue, heart and stomach. Dorper and Merino brain, lungs and testicles had favourable n-6/n-3 ratios. Cholesterol content differed between both organs and breeds. The value of offal as food is discussed further.

A comparison between the effects of day and night cropping on gemsbok (Oryx gazella) meat quality

This study compares the effects of day- and night cropping on the quality of gemsbok meat. Day-cropped animals had higher behavioural scores and cortisol levels (behavioural score: 3.5+/-0.423; cortisol: 136.88+/-2.731nmol/L) than night-cropped animals (behavioural score: 2.1+/-0.378; cortisol: 64.1+/-1.633nmol/L) while night-cropped animals had a higher mean pH(u) (5.54+/-0.013) than day-cropped animals (5.49+/-0.014). The exponential decay model, y=a+b(-)(ct), fitted to the pH data indicated a difference in constant a only (day=5.45+/-0.006; night=5.51+/-0.006). Night-cropped animals produced meat that was darker in colour. The results indicate that day cropping may have elicited more ante-mortem stress although this did not necessarily affect the meat quality adversely, however due to the limitation of sample size, the data may be skewed by outliers and should thus be interpreted with caution.

Meat quality of kudu (Tragelaphus strepsiceros) and impala (Aepyceros melampus): the effect of gender and age on the fatty acid profile, cholesterol content and sensory characteristics of kudu and impala meat.

Game meat has distinct sensory characteristics and favourable fatty acid profiles which differ between species. The SFAs percentage was found to be higher in impala meat (51.12%) than kudu meat (34.87%) whilst the total PUFA was higher in kudu (38.88%) than impala (34.06%). Stearic acid (22.67%) was the major fatty acid in impala and oleic acid in kudu (24.35). Linoleic acid, C20:3n-6 and C22:6n-3 were higher in kudu while C20:4n-6, C20:5n-3 and C22:5n-3 were higher in impala. The PUFA:SFA ratio for kudu (1.22) was higher than for impala (0.73) while impala had a higher n-6 PUFAs to n-3 PUFA ratio (3.76) than kudu (2.20). Kudu was higher in cholesterol (71.42±2.61mg/100gmuscle) than impala (52.54±2.73mg/100gmuscle). Sensory evaluation showed impala had a more intense game aroma and flavour while the initial juiciness of cooked samples of kudu was higher. The results show kudu and impala can be marketed for their unique flavours and aromas as well as being a healthy substitute for other red meats.

A Comparison between the Effects of Day Versus Night Cropping on the Quality Parameters of Red Hartebeest (Alcelaphus buselaphus) Meat

Ante-mortem stress is known to adversely affect meat quality, and cropping methods that minimize stress are key to ensuring acceptable meat quality from wild ungulates. The purpose of this study was to compare the difference in meat quality between day- and nightcropped red hartebeest (Alcelaphus buselaphus). The cropping method had no significant effect on the stress parameters, the ultimate pH of the meat or any of the constants of the exponential decay model of the pH data (y=a+b e (-ct)). No significant differences were found in drip loss, cooking loss or shear force between treatments. Significant correlations were found between carcass pHu versus drip (r = -0.322) and cooking losses (r = -0.323). A significant difference was found for a* (P= 0.048) and chroma (P= 0.032) between day and night-cropped animals. All colour ordinates, except hue angle, were found to be significantly correlated to pHu. The results of this study indicate that if an experienced cropping team is used, neither of the two cropping methods has any adverse effect on the meat quality of red hartebeest.

A comparison between the effects of day and night cropping on greater kudu (Tragelaphus strepsiceros) meat quality.

The greater kudu (Tragelaphus strepsiceros) has become a popular ungulate species for game meat production and the purpose of this study was to determine the effects of day and night cropping on its meat quality. Eight animals were cropped during the day and eight at night. Day-cropped animals had higher mean behavioural scores (perceived amount of ante-mortem stress experienced) and Cortisol levels (behavioural score = 3.0 ± 0.641; Cortisol = 68 ± 1.28 nmol/l) than night-cropped animals (behavioural score = 1.8 ± 0.955; Cortisol = 14 ± 2.15 nmol/l). The muscle ultimate pH (pHu) values differed significantly between the two treatments (day-cropped animals = 5.40 ± 0.030; night-cropped = 5.48 ± 0.041). Significant differences were also found in drip loss (day-cropped = 2.76 ± 0.261%; night-cropped = 1.36 ± 0.361 %) and in shear force between treatments (day-cropped = 3.45 ± 0.171; night-cropped = 4.06 ± 0.237 kg/1.27 cm diameter). No differences were found between the treatments for any of the colour ordlnates, except L* values (day-cropped: 33.45 ± 0.435; night-cropped = 32.13 ± 0.601). The results of this study are Inconclusive in that although day-cropped animals experienced more ante-mortem stress and, as a result produced meat with higher drip loss, they had a lower shear force and a paler colour, which are positive meat quality attributes associated with less stress.

Comparing the Effects on Meat Quality of Conventional Hunting and Night Cropping of Impala (Aepyceros melampus)

In South Africa, night cropping from a vehicle Is commercially used to crop game. Conventional hunting employs the principles of fair chase and usually consists of hunting on foot during the day. The purpose of this study was to compare the meat quality of the Impala (Aepyceros melampus) shot utilizing these two methods. No significant differences In pH45 or pHu were found between the two methods. An exponential decay model (y = a + b-ct) was fitted to the pH data and conventionally hunted animals showed significantly higher rates of pH decline (c = -0.385 ± 0.022 units per hour) than night-cropped animals (c = -0.184 ± 0.019 units per hour) - a phenomenon that may be linked to the ante-mortem stress experienced by the animals, and the cooling rate of the carcasses. Impala conventionally hunted also had significantly higher constants for the pH exponential model (a = 5.424 ± 0.039; b = 1.405 ± 0.034) than the night-cropped Impala (a = 5.295 ± 0.033; b = 1.556 ± 0.029). No significant differences were found with regards to meat quality between treatments except for slight differences In colour (night-cropped: a* = 10.56 ± 0.229, chroma = 12.81 ± 0.235; day-hunted: a* = 11.41 ± 0.245, chroma = 13.78 ± 0.252: the later being slightly darker). The study therefore found that conventional hunting affected the rate of pH decline of the carcasses but did not adversely affect the meat quality compared to night cropping.

Validating a human biotelemetry system for use in captive blue wildebeest (Connochaetes taurinus)

We fitted two blue wildebeest (Connochaetes taurinus) with modified versions of the Equivital™ EQ02 wireless monitoring system to evaluate if the device could accurately measure heart rate and respiration rate in this species whilst anaesthetized as well as whilst fully conscious in captivity. Whilst under anaesthesia, we monitored each animals heart rate and respiration rate using the Equivital™ biotelemetry belt, a Cardell(®) veterinary monitor and manual measurements. The animals were also administered doxapram hydrochloride (Dopram(®) ) and adrenaline intravenously at different times to stimulate changes in respiration and heart rate, respectively. Once 30 minutes of monitoring was completed, we reversed the anaesthetic and left the animals in captivity for 24 hours whilst wearing the Equivital™ belts. After 24 hr, we repeated the anaesthesia and monitoring as well as the administration of the doxapram hydrochloride and adrenaline. Intraclass Correlation Coefficients (ICC) calculated between all three monitoring methods showed moderate to excellent agreements for heart rate on both days (ICC: 0.73-0.98). ICCs calculated between the three methods for respiration rate showed good to excellent agreement between the Equivital belt and the other two methods (0.82-0.92) with the exception of occasions when only poor to fair agreements were found between the Cardell(®) measurements and manual measurements. Heart rate and respiration rate were also found to increase with motion while animals were in captivity. The results indicate that a modified version of the Equivital™ EQ02 system can be used as a potential biotelemetry device for measuring heart and respiration rate in captive blue wildebeest.

Evaluation of butorphanol–azaperone–medetomidine (BAM) in captive blesbok immobilization (Damaliscus pygargus phillipsi)

OBJECTIVE The fixed-dose combination of butorphanol, azaperone and medetomidine (BAM; 30, 12 and 12 mg mL-1, respectively) with subsequent antagonism by naltrexone-atipamezole was evaluated for reversible immobilization of captive blesbok (Damaliscus pygargus phillipsi). STUDY DESIGN Prospective, clinical trial. ANIMALS Sixteen blesbok (four males and twelve females), weighing 52.5-71.0 kg, were immobilized in South Africa. METHODS The total dose of BAM ranged from 0.5 to 0.7 mL for females and 0.7 to 0.9 mL for males. In seven animals chosen randomly, 8000 units of hyaluronidase was added to the dart. Physiologic variables were recorded every 5 minutes beginning at 10-20 minutes after darting. Arterial blood samples were collected three times at 20, 30 and 40 minutes after darting for analysis of blood acid-base status. RESULTS The mean administered doses of BAM were as follows: butorphanol (0.34 ± 0.08 mg kg-1), azaperone (0.14 ± 0.03 mg kg-1) and medetomidine (0.14 ± 0.03 mg kg-1). The inductions were calm and smooth. The mean induction time was 9.6 ± 3.2 minutes with just BAM and 5.1 ± 0.8 minutes with BAM and hyaluronidase combination. Heart rate (45 ± 6 beats minute-1) and respiratory frequency (38 ± 4 breaths minute-1) were stable throughout immobilization. The mean arterial blood pressure for all animals was stable but elevated (137 ± 7 mmHg). Rectal temperature slightly increased over time but remained within an acceptable range. The recovery time after administering naltrexone and atipamezole was 4.8 ± 0.7 minutes. CONCLUSION AND CLINICAL RELEVANCE The BAM combination proved to be reliable and effective in blesbok.

THE EFFECT OF A SLOW-RELEASE FORMULATION OF ZUCLOPENTHIXOL ACETATE (ACUNIL®) ON CAPTIVE BLUE WILDEBEEST (CONNOCHAETES TAURINUS) BEHAVIOR AND PHYSIOLOGICAL RESPONSE

Abstract The study investigated the effect of a slow-release formulation of zuclopenthixol acetate (Acunil®) on blue wildebeest (Connochaetes taurinus) in captivity. Two groups of trials were conducted using either Acunil or a placebo (control). Animals (Acunil: n = 17; placebo: n = 12) were observed for a 12-hr period before the administration of Acunil or the placebo (pretreatment). After 24 hr, animals were administered Acunil (1.5 mg/kg) or a placebo (1.0–3.0 ml of sterile water) and observed again for 12 hr (posttreatment). During both treatments, animals were stimulated every 2 hr for 1 min by a person entering the enclosure (referred to as periods of stimulation). Behavioral observations and continuous heart rate, respiration rate, and motion measurements were taken throughout. Animals treated with Acunil spent more time lying with their heads folded back, eating and standing with their heads down, and less time being vigilant and exploring while walking around. Animals treated with the placebo also spent less time being vigilant and more time lying with heads up. Animals treated with Acunil groomed less while standing and performed less head shaking; no such changes were observed in the control group. Neither Acunil nor the placebo had any effect (P > 0.05) on heart rate. However, overall mean respiration rate was lowered (P = 0.02) when animals were treated with Acunil (pretreatment: 14.5 ± 0.82 breaths/min; posttreatment: 12.5 ± 0.83 breaths/min). Acunil also caused a lowered (P < 0.05) respiration rate during periods when animals were stimulated (pretreatment: 16.2 ± 0.87 breaths/min; posttreatment: 13.7 ± 0.87 breaths/min) and when animals were trotting and being vigilant. No such changes were observed with the placebo. Both placebo- and Acunil-treated animals spent more time being stationary during periods of stimulation. However, Acunil-treated animals also spent less time moving fast when they were stimulated.