In search of the Rhipicephalus (Boophilus) microplus in the western-central regions of the Eastern Cape Province, South Africa.

The southern cattle tick, Rhipicephalus (Boophilus) microplus, is an economically important tick that parasitises cattle and is found on other host species if they graze with cattle. The R. (B.) microplus is a highly adapted tick species prevalent in tropical and subtropical regions of the world. In Africa, it has expanded its range and was reported to supersede the native tick, R. (B.) decoloratus. The objective of the study was to determine the distribution of R. (B.) microplus under different ecological zones in the western-central regions of Eastern Cape Province. Engorged adult blue ticks were collected monthly from 360 randomly selected cattle and free living ticks from six replicate drags of the vegetation over a period of 1 year at Bedford Dry Grassland (BDG), Kowie Thicket (KT) and Bhisho Thornveld (BT). A special attention was paid to the lower perineum, neck, dewlap and ventral body parts which are the preferred sites for blue ticks during sampling. In this study, 9 species of ticks which grouped under 5 genera were identified. The identified species of ticks were Amblyomma hebraeum, Haemaphysalis elliptica, Hyalomma rufipes, Ixodes pilosus, R. (B.) decoloratus, R. appendiculatus, R. evertsi evertsi, R. follis and R. simus. Only adult R. (B.) decoloratus (n = 8090) ticks were collected from cattle between April 2016 and March 2017. A total of 4382 females and 3708 males of R. (B.) decoloratus were recovered during the survey. Of the ticks (n = 2885) collected from the vegetation, R. (B.) decoloratus was the most abundant species with a relative prevalence of 58.16%, followed by R. appendiculatus (18.37%) and R. evertsi evertsi (16.90%). Least abundant ticks were H. rufipes (2.98%), A. hebraeum (2.46%), H. elliptica (0.38%), R. follis (0.34%), I. pilosus (0.24%) and R. simus (0.17%). The distribution of R. (B.) decoloratus ticks differ significantly (P < 0.05) among the vegetation types. Significantly more (P < 0.05) engorged R. (B.) decoloratus were collected in KT during summer season (1.39 ± 0.063 females and 1.30 ± 0.063 males) compared to other vegetation types. The R. (B.) decoloratus larvae were significantly higher (P < 0.05) in BT (20.56±1.154) and KT (18.50±1.154) vegetation types during the spring season. R. (B.) microplus was not found in the present study, signifying that it is not yet established in western-central regions of the Eastern Cape Province and as such, continuous monitoring would be advisable.

Effects of production systems on the carcass and meat quality characteristics of spent laying hens.

This study evaluated the carcass characteristics and meat quality attributes of spent laying hens raised under conventional battery cage and free-range systems. Thirty free-range and 30 conventional battery-caged Lohmann Brown-Elite spent laying hens of 53 and 40 wk of age, respectively were obtained from a commercial egg producer. Carcass, portion, and organ weights and percentages were determined. Physicochemical analyses were performed on thigh and breast meat samples. Caged hens had heavier (P ≤ 0.05) warm and cold carcasses, thighs, wings, and feet. The percentages of the breast (26.1 ± 0.51 vs. 28.3 ± 0.28), drum, breast bones, breast thaw and cooking loss, and thigh cooking loss were higher (P ≤ 0.05) for free-range than for caged hens. Free-range hens had heavy (P ≤ 0.05) gizzards (33.9 ± 1.04 vs. 30.5 ± 0.73) and bones and a lower (P ≤ 0.05) breast meat percentage (47.3 ± 0.94 vs. 51.7 ± 1.35). Meat redness (a*) (0.54 ± 0.222 vs. 1.40 ± 0.135) and hue angle, skin redness (a*), breast (12.37 ± 0.411 vs. 17.10 ± 0.751), and thigh (29.68 ± 0.306 vs. 39.75 ± 0.826) Warner-Bratzler shear force values (N), breast moisture, and thigh ash content were higher (P ≤ 0.05) for free-range hens. Caged hens had a higher (P ≤ 0.05) thigh thaw loss percentage and breast ash content. Production system significantly influenced the carcass characteristics and meat quality of spent laying hens. The results of this study supply baseline information for the utilization of spent laying hens by the poultry industry and consumers.

Ecological preferences and seasonal dynamics of ticks (Acari: Ixodidae) on and off bovine hosts in the Eastern Cape Province, South Africa.

A total of 31,425 ticks were collected from 10 cattle and also from six drag-samples during the 12-month study period. Adult ticks were removed from the right hand side of each animal and all instars of ticks were placed in containers filled with 70% ethanol. Based on morphological traits, 10 tick species were identified: Rhipicephalus (Boophilus) decoloratus (32.5%), R. evertsi evertsi (18.8%), R. appendiculatus (17.3%), Amblyomma hebraeum (16.3%), R. simus (7.7%), Ixodes pilosus (3.8%), Hyalomma rufipes (3.5%), R. follis (0.08%), Haemaphysalis elliptica (0.04%), H. silacea (0.02%). The southern African yellow dog tick, H. elliptica, was only found on vegetation. The agro-ecological zones differ significantly in tick species and their distribution. The A. hebraeum and R. evertsi evertsi counts were higher in Kowie Thicket (KT) during summer season (2.05 ± 0.01 and 1.00 ± 0.09, respectively) compared to Bedford Dry Grassland (BDG) and Bhisho Thornveld (BT) veld types. In all vegetation types, R. appendiculatus had higher counts in KT in spring (0.91 ± 0.08), summer (0.78 ± 0.08) and winter (0.78 ± 0.08). Rhipicephalus (Boophilus) decoloratus was more frequent in the BT (1.78 ± 0.11) during the summer season. BDG had lower tick infestation with R. evertsi evertsi being the most frequent species in summer. No H. rufipes was collected in the KT. Of epidemiological interest, R. (B.) microplus was absent in the study area which needs further investigation. Within the context of this study, we found agro-ecological differences and seasonal variations to have influence on tick species distribution.

Thermotolerance, health profile and cellular expression of HSP90AB1 in Nguni and Boran cows raised on natural pastures under tropical conditions.

Boran (n=15) and Nguni (n=15) cows were used in a study to determine the effect of breed, age and coat colour on the concentration of heat shock protein 90 (HSP90AB1), physiological rectal and skin temperature, and markers of health. The cows were exposed to summer heat stress and Boran cows had higher significant (P<0.05) skin temperature (35.1±0.42°C) as compared to the Nguni cows (36.0±0.38°C). Nguni cows had higher body thermal gradients than the Boran cows. Boran cows had thicker skin (P<0.05) and longer hairs (24.3±2.26mm) than their Nguni counterparts (20.2±2.00mm). The HSP90AB1 concentration was increased in Boran cows, although breed had no significant (P>0.05) influence. Significantly (P<0.05) high urea and total cholesterol was recorded in Boran cows. Coat colour had a significant (P<0.05) effect on the weight and rectal temperature of the study animals. Coat colour and age had no significant effect (P>0.05) on the concentration of HSP90AB1, although older cows (≥9 years) had higher concentrations (5.4±1.29ng/ml). Age had a significant (P<0.05) effect on packed cell volume, neutrophil/lymphocyte, urea, total protein and gamma-glutamyl transferase whereas cows with ≥9 years had more concentrations than young ones. Age significantly (P<0.05) influenced hair length, skin temperature and the thermal gradients. Breed was positively correlated (P<0.001) to coat colour, age, body condition score, weight and temperature humidity index while negatively correlated to urea and total cholesterol. It was concluded that Nguni cows were more adaptable to hot environments than the Boran cows as the latter were unable to balance thermal load between their bodies and the environment.

Hair coat characteristics and thermophysiological stress response of Nguni and Boran cows raised under hot environmental conditions.

Breed, age, coat colour, month and temperature humidity index (THI) influence on body weight (W), body condition score (BCS), thermophysiological variables (rectal temperature (Tr), skin temperature (Tsk)) and hair length was studied in Nguni (n = 19) and Boran (n = 16). As a result of this study, breed influenced W, BCS and Tsk on the neck and belly (P < 0.05). The BCS and W of Nguni cows were higher than the Boran cows. Hair length of both breeds increased from February to August. The THI influenced thermophysiological variables (P < 0.05). Increased Tr for both breeds was recorded in February and April, respectively (P < 0.05). Month influenced Tsk and June recorded lower values (P < 0.05). Younger cows (3-8 years) had lower weight and high Tr and Tsk (P < 0.05). Nguni cows had high neck and thurl temperatures in June while Boran cows had the highest in August (P < 0.05). Red, dun and white-black Boran cows had increased BCS. Nguni cows with red, fawn and white cows had high BCS. Fawn-coloured Nguni cows and white-brown Boran cows had the more weight than cows with other colours compared in the study. White-red Nguni and Boran cows recorded the highest Tr. For Nguni cows, neck and belly temperatures were significantly (P < 0.001) correlated to thurl temperature. Boran cows had significant (P < 0.001) correlations for THI and neck, belly and thurl temperatures. The current study found that Nguni cows were more adapted to the prevailing bioclimatic changes. However, Boran cows have the potential of performing well under heat stress conditions over time.

Genetic parameters for tick counts across months for different tick species and anatomical locations in South African Nguni cattle.

The objective of the study was to characterise genetic parameters across months for different tick species and anatomical locations in South African Nguni cattle. Tick counts were conducted monthly, over a 2-year period, on 586 Nguni cattle under natural infestation, from four herds located in different provinces of South Africa. The counts were recorded for six species of ticks (Amblyomma hebraeum, Rhipicephalus evertsi evertsi, Rhipicephalus decoleratus and microplus (Boofilids), Rhipicephalus appendiculatus, Rhipicephalus simus and Hyalomma marginatum) attached on eight anatomical locations on the animals and were summed by species and anatomical location. Heritability estimates, phenotypic and genetic correlations were estimated on a monthly basis using mixed linear models, fitting univariate and bivariate sire models. Fixed effects considered were location, sex, year and age as a covariate. Tick counts were higher in the hot months, and A. hebraeum was the most dominant tick species. Heritability estimates for tick count varied by month and trait and ranged from 0 to 0.89. Genetic correlations were mostly positive, and low to high, with some negative correlations with high standard error. Phenotypic correlations were low to moderate. In general, high genetic correlations were observed between whole body count and the anatomical location counts, suggesting that it may not be necessary to conduct whole body counts. Counts from the belly and perineum appeared to be the most suitable surrogate traits for whole body count. These findings provide useful information for developing strategies for the practical implementation of genetic selection, as a supplement to the traditional tick control measures.

Activities of some stress enzymes as indicators of slaughter cattle welfare and their relationship with physico-chemical characteristics of beef.

The study determined the activities of creatine kinase (CK) and lactate dehydrogenase (LDH) in transported cattle as indicators of welfare and how they relate to beef quality. A total of 219 (n=219) (85 Beefmaster, 48 Charolaise, 32 Holstein-Friesian and 54 nondescript) cattle brought to the abattoir for slaughter were used in the study. Disposable vacutainer tubes with anticoagulant (ethylenediaminetetraacetic acid) were used to collect 4 ml of blood samples to determine the activities of CK and LDH. The measurements of pHu and colour coordinates (L*, a* and b*) were carried out at 48 h after slaughter on the representative samples of muscularis longissimuss thoracis et. lumborum (LTL). Longer distance travelled by cattle had a significant effect (P3000 to 5000) and those that travelled for 1263 km had lower CK activities (1000). The activities of LDH were observed in cattle that travelled for 366 and 1012 km (7000) and for those that travelled for 877 and 922 km (6000). Results of the principal component analysis showed that the first three principal components (PCs) explained about 53% of the total variability. The first PC was correlated with meat quality attributes (pHu, Tm, a* and b* values). The activities of CK and LDH were related and useful to define the second PC. However, CK and LDH were not related to beef quality. Therefore, CK and LDH can be used as indicators of welfare in slaughter cattle but cannot be used to predict the quality of meat.

Conservation of indigenous cattle genetic resources in Southern Africa's smallholder areas: turning threats into opportunities - A review.

The current review focuses on characterization and conservation efforts vital for the development of breeding programmes for indigenous beef cattle genetic resources in Southern Africa. Indigenous African cattle breeds were identified and characterized using information from refereed journals, conference papers and research reports. Results of this current review reviewed that smallholder beef cattle production in Southern Africa is extensive and dominated by indigenous beef cattle strains adaptable to the local environment. The breeds include Nguni, Mashona, Tuli, Malawi Zebu, Bovino de Tete, Angoni, Landim, Barotse, Twsana and Ankole. These breeds have important functions ranging from provision of food and income to socio-economic, cultural and ecological roles. They also have adaptive traits ranging from drought tolerant, resistance to ticks and tick borne diseases, heat tolerance and resistance to trypanosomosis. Stakeholders in the conservation of beef cattle were also identified and they included farmers, national government, research institutes and universities as well as breeding companies and societies in Southern Africa. Research efforts made to evaluate threats and opportunities of indigenous beef cattle production systems, assess the contribution of indigenous cattle to household food security and income, genetically and phenotypically characterize and conserve indigenous breeds, and develop breeding programs for smallholder beef production are highlighted. Although smallholder beef cattle production in the smallholder farming systems contributes substantially to household food security and income, their productivity is hindered by several constraints that include high prevalence of diseases and parasites, limited feed availability and poor marketing. The majority of the African cattle populations remain largely uncharacterized although most of the indigenous cattle breeds have been identified.

Effect of genotype and age on some carcass and meat quality traits of beef carcasses subjected to the South African classification system.

Genotype and age effects on pH24, L*, a*, b*, tenderness (WBSF), cooking (CL %), and thawing loss (TL %) of beef carcasses subjected to the South African classification system were determined. Carcass traits (bruising, subcutaneous fat (SF), and conformation) were also measured. Meat quality measurements were taken on the longissimus thoracis et lumborum (n=175) of A, AB, B, and C carcasses from Angus, Bonsmara, Fleckvieh, Non-descript, and Simmental genotypes. No bruises were evident in all carcasses. All carcasses scored medium conformation (class 3) while in SF classification, class 2 had the greatest frequency (66.3%). Genotypic effects (P<0.05) were observed for a*, hue angle (HA), pH24, TL%, CL%, and WBSF between steers with six, seven, and eight incisors. Notable differences (P<0.05) were observed for tenderness where Angus and Simmental had least tender meat while Non-descript and Fleckvieh had the tenderest meat within the C-age class. Meat quality varied within animals of the same age-class across genotypes.

Effects of transport distance, lairage time and stunning efficiency on cortisol, glucose, HSPA1A and how they relate with meat quality in cattle.

This study determined the effects of distance travelled, lairage duration and number of stunning shots on the plasma levels of bovine heat shock protein 70 (HSPA1A), cortisol (CORT) and glucose (GLU) and their relationship with beef quality. There were positive correlations among HSPA1A, GLU, CORT, a*, b* and the HUE angle. Animals that were stunned more than once had the highest HSPA1A (13.61±2.874ng/ml) and CORT (109.36±8.373nmol/L) levels. Animals that travelled for 200<400km had lower HSPA1A expression (8.29±2.026ng/ml) than those that were transported for 400<800km (12.11±2.548ng/ml) and <200km (17.32±2.362ng/ml). Lairage duration affected (P<0.05) the expression of HSPA1A, GLU and CORT levels. Animals stunned more than once had elevated CORT and HSPA1A levels. HSPA1A, CORT and GLU were related to beef quality. Stunning of animals more than once increased the levels of blood CORT and HSPA1A.

Effect of sex and time to slaughter (transportation and lairage duration) on the levels of cortisol, creatine kinase and subsequent relationship with pork quality.

The study determined the effect of sex and time to slaughter on cortisol and creatine kinase levels, and pork quality in commercial crossbred pigs. Saliva samples were before collected transportation, on arrival at the abattoir, and after a 20 hour lairage period. Cortisol levels from saliva (SC), serum (SeC) and urine (UC) were determined. Creatine kinase (CK) levels were determined from serum samples. Fifteen boars vs. 15 gilts were immediately slaughtered on arrival (SOA), and the other 15 boars vs. 15 gilts were rested for 20 h before slaughter. Meat quality parameters were also determined. In both sexes, SC significantly increased in response to time to slaughter. There was a significant interaction of sex and time to slaughter on SeC. Gilts had higher CK levels and lower muscle L* values than boars. There were correlations among baseline SC, SeC, UC and most meat quality parameters. Time to slaughter influenced levels of SC, UC, CK and pork quality between boars and gilts.

Seasonal variation in coat characteristics, tick loads, cortisol levels, some physiological parameters and temperature humidity index on Nguni cows raised in low- and high-input farms.

Seasonal variations in hair length, tick loads, cortisol levels, haematological parameters (HP) and temperature humidity index (THI) in Nguni cows of different colours raised in two low-input farms, and a commercial stud was determined. The sites were chosen based on their production systems, climatic characteristics and geographical locations. Zazulwana and Komga are low-input, humid-coastal areas, while Honeydale is a high-input, dry-inland Nguni stud farm. A total of 103 cows, grouped according to parity, location and coat colour, were used in the study. The effects of location, coat colour, hair length and season were used to determine tick loads on different body parts, cortisol levels and HP in blood from Nguni cows. Highest tick loads were recorded under the tail and the lowest on the head of each of the animals (P < 0.05). Zazulwana cows recorded the highest tick loads under the tails of all the cows used in the study from the three farms (P < 0.05). High tick loads were recorded for cows with long hairs. Hair lengths were longest during the winter season in the coastal areas of Zazulwana and Honeydale (P < 0.05). White and brown-white patched cows had significantly longer (P < 0.05) hair strands than those having a combination of red, black and white colour. Cortisol and THI were significantly lower (P < 0.05) in summer season. Red blood cells, haematoglobin, haematocrit, mean cell volumes, white blood cells, neutrophils, lymphocytes, eosinophils and basophils were significantly different (P < 0.05) as some associated with age across all seasons and correlated to THI. It was concluded that the location, coat colour and season had effects on hair length, cortisol levels, THI, HP and tick loads on different body parts and heat stress in Nguni cows.

Farmers' perceptions and knowledge of cattle adaptation to heat stress and tick resistance in the eastern cape, South Africa.

The objective of this study was to determine the perceptions and knowledge of farmers of heat stress and tick resistance in cattle. A cross-sectional survey was conducted and 110 farmers in four villages in the sour and sweet velds of the Eastern Cape Province, South Africa were interviewed. The associations among area (municipality), gender, age, level of education, employment and religion were computed using Chi-square tests. The majority of the respondents had on average 4 bulls, 4 cows, 4 heifers, 4 calves, and 4 oxen. Milk was considered as the major (28.3%) reason for keeping cattle. Most farmers owned non-descript (72.6%), and Nguni (45.3%) cattle because of their heat tolerance (54.7%), tick resistance (54.7%), and milking ability (28.2%) traits. Excessive panting (56.6%) and disease transmission (76%) were regarded as the major effects of heat stress and tick infestation in cattle, respectively. About 50% of the respondents agreed that hair length influences tick resistance and 47.17% considered coat colour when acquiring cattle. In the sampled areas, ticks were prevalent in the summer season (93%), and 77.36% of the respondents use acaricides every fortnight. Gall sickness was reported to be a major problem in the cattle herds by 36.79% of the respondents. Our results showed that farmers in the two municipalities had knowledge of cattle adaptation to heat stress and tick resistance.

Bruising in slaughter cattle and its relationship with creatine kinase levels and beef quality as affected by animal related factors.

The objective of the study was to determine the effects of animal related factors on bruising in slaughter cattle, creatine kinase (CK) and beef quality. Three hundred and twenty one cattle from three breeds (108 Bonsmara, 130 Beefmaster and 83 Brahman) were used in this study. The animals were grouped as follows: Group 1 (16 months old), Group 2 (18 months old) and Group 3 (24 months old). At exsanguinations, blood samples for CK determination were collected using disposable vacutainer tubes. Muscularis longissimus thoracis et lumborum (LTL) was collected 24 h after slaughter to determine the colour (L*, a*, and b*) and ultimate pH (pHu) of beef. Breed, sex and age had significant effects (p<0.05) on bruising score, CK levels and beef quality. Bonsmara breed had the highest (80%) bruising score percentage, CK (705.3±80.57 U/L) and pHu (6.3±0.05) values while the Bonsmara had the highest L* (24.8±0.78) a* (17.5±0.53) and b* (12.8±0.53) values. Higher CK levels were also observed in winter compared to summer, spring and autumn respectively. Therefore, animal factors (sex, breed and animal age at slaughter) contribute to the development of bruises and have an effect on the levels of CK and meat quality. It was also concluded that there is no significant relationship between meat parameters (L,* a*, and b*) and CK levels.

Fatty acid composition and oxidative stability of breast meat from broiler chickens supplemented with Moringa oleifera leaf meal over a period of refrigeration.

Effects of diets supplemented with or without Moringa oleifera leaf meal (MOLM) on fatty acid (FA) composition and oxidative stability of broiler breast meat during refrigerated storage was determined. Dietary treatments (T) were as follows: T1, positive control, 668g/ton Salinomycin and 500g/ton Albac; T2, T3 and T4 contained graded levels of MOLM at 1%, 3% and 5% of dry matter (DM) intake, respectively; and T5, a negative control (0% additives). Oxidative stability was evaluated by thiobarbituric acid reactive substances (TBARS) on day (D) 1-8 of storage at 4°C; and FA analysis was done on samples obtained on D1 and D8. Significant effects on TBARS were noted on day (D) 1, 3, 4 and 7; increased with increasing storage time, and with increase in MOLM supplementation. Highest (P<0.05) C18:0 and C15:0 levels were noted on D1 in T2; C20:0 in T4 on D8; C20:2, C20:3n6 and C22:6n3 in T2; C18:3n6 and P/S ratio in T4 on D1; and n-3 in T3. Thus, despite the high SFA content, additive supplementation of M. oleifera leaf meal up to 5% of the bird's DMI improved the FA profile and reduced lipid oxidation in broiler breast meat.

Atherogenicity index and health-related fatty acids in different stages of lactation from Friesian, Jersey and Friesian×Jersey cross cow milk under a pasture-based dairy system.

The objective of the study was to investigate the effect of stage of lactation on the fatty acid profiles of milk from Friesian, Jersey and Friesian×Jersey cows. Linoleic acid in pastures was highest in the second phase which coincided with mid-lactation days (p<0.05). Highest milk moisture content and lowest fat free dry matter content was seen in early lactation (p<0.05). Higher fat content was observed in late lactation than early lactation. Highest butyric, caproic, linoleic, omega-6 and polyunsaturated fatty acids were observed for milk from Friesian cows. Highest conjugated fatty acids, α-linolenic acid, linoleic acid, saturated fatty acids, polyunsaturated fatty acids, omega-6, and omega-3 were observed in early lactation. Atherogenicity index and desaturase activity indices were highest in late lactation. In conclusion, stage of lactation and genotype affected milk health-related fatty acid profiles.

Effects of transportation time, distance, stocking density, temperature and lairage time on incidences of pale soft exudative (PSE) and the physico-chemical characteristics of pork.

The study determined the effects of transportation time, distance, stocking density, temperature and lairage time on incidences of PSE and pork quality. Frequencies of PSE cases in stocking density categories within transport duration classes were determined. General linear models, regression and the principal component (PC) analysis were used to analyse the data. Highest incidences of PSE were recorded in autumn season while lowest incidences were recorded in the spring season. Transportation time and stocking density significantly affected pHu and ultimately PSE incidences although there were no interactive effects. Highest risks of PSE occurrence were observed with more space allowance. The highest incidences of PSE were observed for animals that had travelled for two hours while the PSE cases were lower in animals that travelled for longer times. Distance travelled and transportation time had significant effects (P<0.05) on thawing loss (TL) % of pork. No relationships were reported between the other pre-slaughter variables and pork quality attributes. With the exception of transportation time and distance travelled which had a positive relationship with TL%, variation in other pre-slaughter variables did not affect meat quality variables. The risks of PSE occurrence were dependent on stocking density and transportation time.

Chemical composition, fatty acid content and antioxidant potential of meat from goats supplemented with Moringa (Moringa oleifera) leaves, sunflower cake and grass hay.

The present study determined the chemical composition, fatty acid (FA) content and antioxidant capacity of meat from goats supplemented with Moringa oleifera leaves (MOL) or sunflower cake (SC) or grass hay (GH). The meat from goat supplemented with MOL had higher concentrations of total phenolic content (10.62±0.27 mg tannic acid equivalent E/g). The MOL significantly scavenged 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic-acid (ABTS) radical to 93.51±0.19% (93.51±0.19%) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical to 58.95±0.3% than other supplements. The antioxidative effect of MOL supplemented meat on catalase (CAT), reduced glutathione (GSH), superoxide dismutase (SOD) and lipid oxidation (LO) was significantly (P<0.05) higher than other meat from goat feed on grass hay or those supplemented with sunflower seed cake. The present study indicated that the anti-oxidative potential of MOL may play a role in improving meat quality (chemical composition, colour and lipid stability).

Effect of Acacia karroo Supplementation on Growth, Ultimate pH, Colour and Cooking Losses of Meat from Indigenous Xhosa Lop-eared Goats.

The objective of the study was to determine the effect of Acacia karroo supplementation on growth, ultimate pH, colour and cooking losses of meat from indigenous Xhosa lop-eared goats. Eighteen castrated 4-month-old kids were used in the study until slaughter. The kids were subdivided in two treatment groups A. karroo supplemented (AK) and non-supplemented (NS). The supplemented goats were given 200 g per head per d of fresh A. karroo leaves. The kids were slaughtered on d 60 and sample cuttings for meat quality assessment were taken from the Longistimus dorsi muscle. The supplemented kids had higher (p<0.05) growth rates than the non-supplemented ones. The meat from the A. karroo supplemented goats had lower (p<0.05) ultimate pH and cooking loss than the meat from the non-supplemented goats. Acacia karroo supplemented goats produced higher (p<0.05) b* (yellowness) value, but supplementation had no significant effect on L* (lightness) and a* (redness) of the meat. Therefore, A. karroo supplementation improved growth performance and the quality of meat from goats.

The Effects of Pre-slaughter Stress and Season on the Activity of Plasma Creatine Kinase and Mutton Quality from Different Sheep Breeds Slaughtered at a Smallholder Abattoir.

The objective of the current study was to determine the effect of pre-slaughter stress, season and breed on the activity of plasma creatine kinase (CK) and the quality of mutton. One hundred and seventy-three (173) castrated sheep from Dormer (DM), South African Mutton Merino (SAMM), Dorper (DP) and Blackhead Persian (BP) sheep breeds were used in the study. The animals were grouped according to age-groups as follows: Group 1 (6 to 8 months), Group 2 (9 to 12 months) and Group 3 (13 to 16 months). Blood samples were collected during exsanguinations using disposable vacutainer tubes for CK analysis. Representative samples of the Muscularis longissimuss thoracis et. lumborum (LTL) were collected from 84 castrated sheep, of different breeds (28 per breed) 24 h after slaughter. The following physico-chemical characteristics of mutton were determined; meat pH (pH24), color (L*, a* and b*), thawing and cooking losses and Warner Braztler Shear Force (WBSF). The activity of plasma CK was significantly higher (p<0.001) in summer (1,026.3±105.06) and lower in winter (723.3±77.75). There were higher values for L* (33.7±0.94), b* (11.5±0.48) and WBSF (29.5±1.46) in summer season than in winter season; L* (29.4±0.64), b* (10.2±0.33) and WBSF (21.2±0.99). The activity of plasma CK was influenced by the type of breed with Dormer having the highest (p>0.001) levels (1,358.6±191.08) of CK. South African Mutton Merino had higher values for pH24 (5.9±0.06), L* (34.2±0.97), b* (12.2±0.50) and WBSF (26.8±1.51) and Blackhead Persian had higher values (35.5±2.17) for cooking loss (CL%) than the other breeds. Computed Principal Component Analyses (PCA) on the activity of plasma CK and physico-chemical characteristics of mutton revealed no correlations between these variables. However, positive correlations were observed between pH24, L*, a*, b*, CL% and WBSF. Relationships between pre-slaughter stress, CK activity and physico-chemical characteristics of mutton were also observed. It was therefore concluded that although mutton quality and creatine kinase were not related, pre-slaughter stress, season and breed affected the activity of creatine kinase and mutton quality.