Driving forces for changes in geographic range of cattle ticks (Acari: Ixodidae) in Africa: A review

Ticks are the most important external parasites of cattle and are known to transmit more pathogens than any other group of arthropods worldwide. About 80% of the world cattle population is at risk of ticks and tick-borne diseases, causing a global annual loss of $US22–30 billion. In Africa, the impact of ticks is ranked high, and they transmit diseases such as cowdriosis, anaplasmosis, bovine babesiosis and theileriosis. A range expansion of ixodid ticks has been observed in Africa, in particular for the genera Amblyomma and Rhipicephalus, which contribute greatly to cattle loss owing to morbidity and mortality. Distributional changes in ticks can lead to the emergence or re-emergence of infectious and parasitic diseases. Climate change is frequently invoked as the primary cause of tick distribution, but it is not the only factor. Human lifestyle changes, including transportation of livestock within countries, have promoted the introduction of new tick species and the diseases they transmit. One such example is the spread of the Asian cattle tick Rhipicephalus (Boophilus) microplus to West Africa. Rhipicephalus (Boophilus) microplus was recorded for the first time in Namibia and was probably introduced into Namibia from South Africa. Likewise, Amblyomma variegatum, the vector of heartwater disease, has the largest distribution in Africa. Its spread is outside its native range and it is considered the second most invasive tick species after R. (B.) microplus on the continent. Rhipicephalus (Boophilus) microplus is a one-host tick that is reported to be resistant to conventional acaricides and this contributes largely to its spread into non-endemic areas.Keywords: Acaricide resistance, climate change, epidemiology, range expansion, tick ecolog

Animal welfare in multipurpose cattle production Systems and its implications on beef quality

Animal welfare and its influence on beef production are major  considerations in many developed countries. In the developing world, where food insecurity and poverty are prevalent, the welfare of animals receives low priority due to factors such as traditional customs and beliefs, lack of knowledge in animal handling and sub standard handling facilities. This is worsened by the fact that cattle are used for several purposes, such as meat production, milk production, draught power and traditional ceremonies. Research on animal welfare and how it relates to animal production have been done in the developed world. The objective of this study is to discuss indicators of animal welfare assessment, their impact on meat quality and applications to improve beef production in developing countries.Key words: Behavioural assessments, flight zones, meat quality, ritual slaughter

Layer performance, fatty acid profile and the quality of eggs from hens supplemented with Moringa oleifera whole seed meal

The objective of the study was to determine how the partial supplementation of Moringa oleifera whole seed meal (MOWSM) would affect layer performance, egg quality and egg fatty acid profile. One hundred and forty-four Hy-Line hens in early-lay (20-weeks-old), with an average body weight of 1.45 kg were randomly allocated to four dietary treatments which were formulated to meet or exceed the National Research Council standards for brown-egg laying hens. Dietary treatments consisted of 0 (control), 1, 3, and 5% MOWSM. Layer performance was monitored over a period of 8 weeks. The inclusion of MOWSM in layer diets reduced feed intake, bodyweight, the rate of lay, egg weight, and egg mass. Yolk colour was significantly improved by 1, 3 and 5% inclusion levels, while the albumen height decreased. The albumen weight, yolk weight, eggshell weight, eggshell thickness, and egg shape index showed no statistical differences across all treatment groups. Similarly, the saturated fatty acid profile was also not affected. Palmitoleic acid decreased with the increase in MOWSM inclusion, whilst linolelaidic acid increased. The atherogenicity index was not affected by MOWSM inclusion, while the thrombogenicity index increased when compared to the control diet. It was concluded that, although MOWSM inclusion improved yolk colour, maintained external egg quality, and improved the fatty acid profile, the deleterious effect that it had on layer performance indicated that it may not be fed to early-lay hens at these respective levels.Keywords: Alternative protein, egg production, laying hens, oil seed

Correlations among sensory characteristics and relationships between aroma scores, flavour scores, off-flavour scores and off-flavour descriptors of chevon from four goat genotypes

The objective of the current study was to determine the correlations among sensory characteristics and relationships between flavour scores and off-flavour descriptors of chevon. Forty-eight male 6-months old Xhosa lop-eared, Nguni, Xhosa-Boer cross and Boer goat kids were kept at the University of Fort Hare Farm until slaughter. Sample cuttings for meat tasting were made from the hind leg. Aroma score was independent of off-flavour descriptors from meat from all goat genotypes (P > 0.05). Off-flavour descriptors and their frequencies varied with genotypes. There were significant (P< 0.001) correlations between most sensory characteristics of meat across genotypes although; there were variations in some goat genotypes. There were relationships among sensory scores, while flavour scores, aroma scores, off-flavour scores and off-flavour descriptors of chevon are independent. This implies that, all sensory characteristic scores and off-flavour descriptors should be included when carrying out sensory evaluations with meat from different goat genotypes.Key words: Goat genotypes, off-flavours, off-flavour descriptors, sensory  evaluations, sensory score relationships

Consumer sensory evaluation of meat from South African goat genotypes fed on a dietary supplement

The objective of the study was to evaluate the effect of genotype and supplementary feeding on sensory scores of chevon from different indigenous goat genotypes prepared using different thermal treatments. 48 6-month-old Xhosa lop-eared (XLE), Nguni (NGN), Xhosa-Boer cross (XBC) and Boer (BOR) castrated goats with a body weight range of between 20 and 25 kg was used in the study. Half of the goats were supplemented with 200 g per head per day of sunflower cake. A consumer sensory evaluation was done with consumers of different ages, tribes and gender. In the non-supplemented XLE and BOR goats, the aroma intensity scores of the fried meat were significantly higher than the cooked meat. Female respondents gave higher (P < 0.05) scores than male respondents for both cooked and fried meat on aroma intensity. Shona consumers gave higher (P < 0.05) aroma intensity scores than the Xhosa and the Zulu consumers for both cooked and fried meat. In the non-supplemented goats, fried meat for all the genotypes was superior (P < 0.05) to the cooked meat for initial impression of juiciness. The age and gender of respondents and thermal treatment influenced initial impression of juiciness scores (P < 0.05). In meat from the non-supplemented XLE and NGN goats, the consumers gave higher (P < 0.05) muscle fibre and overall tenderness scores in cooked meat than the fried meat.Key words: Dietary supplementation, fried chevon, cooked chevon, Xhosa lop-eared goats, Nguni goats, Boer goats

Effect of parity on the proximate composition and fatty acid profile of milk from Nguni cattle grazing on natural pastures

The objective of the study is to establish the effect of parity on milk composition and fatty acid profiles of Nguni cattle milk. Forty-four Nguni cows with parities ranging from 1 to 13 were included in this study. The cows were grouped to three parity groups: parity group 1 (parity 1 to 5), parity group 2 (parity 6 to 9) and parity group 3 (parity 10 to 13). Samples of the milk were collected in a single day and the milk was analyzed using gas chromatography. Parity had no effect of proximate composition (fat,DMC and moisture %) on milk. The fatty acids (FA) present in the milk of the three parity groups were primarily palmitic (33.3 to 40.5%), oleic (16.3 to 20.3%), myristic (12.5 to 13.2%) and stearic (10.8 to 11.7%) acids, in decreasing order of proportion. Milk from parity group 3 cows contained significantly (p < 0.05) higher proportions of butyric, myristoleic, oleic, eicosenoic, conjugated linoleic acid (CLA), arachidonic and eicosopentaenoic acids when compared with the other two parity groups. Parity group 3 also had significantly (p < 0.05) higher values for total SFA, MUFA, PUFA, omega 3 fatty acids and n-6/n-3 ratio than the other two parity groups. Cows in higher parities generally have higher values forindividual fatty acids when compared to those in lower parities. Parity is therefore, an important factor that must be considered when assessing milk quality in Nguni cows.Key words: Conjugated linoleic acid, fat content, harsh environment, fatty acid profile, milk composition

Relationship between pre-slaughter stress responsiveness and beef quality in three cattle breeds

The relationship between stress responsiveness and beef quality of 40 Nguni, 30 Bonsmara and 30 Angus steers was determined. The L* values, pHu, cooking loss (CL) and Warner-Bratzler shear force (WBSF) were determined. Catecholamine levels were determined from urine samples collected at slaughter. Bonsmara steers had the highest (P \u3c 0.05) levels of catecholamines with respective epinephrine, norepinephrine and dopamine concentrations of 10.8, 9.7 and 14.8 nmol/mmol. Nguni steers had the lowest (P \u3c 0.05) levels of catecholamines, with respective catecholamine concentrations of 5.1, 4.3 and 4.0 nmol/mmol. In the Nguni steers, there were significant (P \u3c 0.05) correlations between catecholamines and L* and between dopamine and tenderness in meat aged for two days (WBSF2). In the Bonsmara, dopamine was correlated (P \u3c 0.05) pHu, WBSF2 and CL. No significant correlations were found in the Angus. Therefore the relationship between stress responsiveness and certain beef quality traits may not be similar in different breeds

Physico-chemical quality attributes and fatty acid profiles of pork from Windsnyer and Large White gilts

The objective of the study was to assess the physico-chemical pork quality attributes and fatty acid profiles of indigenous Windsnyer (WS) and Large White (LW) gilts. Twelve gilts of each breed were fed similar commercial diets from weaning until slaughter at the age of 21 weeks. The m. longissimus thoracis et lumborum was sampled. Differences in muscle pH values obtained 24 hours post mortem (pH24) were not significant in pork from the WS or LW gilts. Pork lightness 24 hours post mortem (L*24) was significantly lower in WS gilts than in LW gilts. Muscle saturated fatty acids (SFA) were higher in WS gilts than LW gilts. Fat of LW gilts had higher polyunsaturated (PUFA), n-6 fatty acids, n-3 fatty acids and PUFA: SFA ratio than WS gilts. The study showed preferential attributes of pork from LW gilts than from WS gilts. The accrued information could benefit the food industry by assisting researchers and nutritionists to interpret the quality of pork from different pig genotypes for health-conscious consumers. Furthermore, it aids in determining the concern about pork as a cardiovascular risk factor and acts as a planning tool for public-health programmes.Keywords: Fatty acids, indigenous pigs, pork quality, tendernes

Relationship between pre-slaughter stress responsiveness and beef quality in three cattle breeds

The relationship between stress responsiveness and beef quality of 40 Nguni, 30 Bonsmara and 30 Angus steers was determined. The L* values, pHu, cooking loss (CL) and Warner-Bratzler shear force (WBSF) were determined. Catecholamine levels were determined from urine samples collected at slaughter. Bonsmara steers had the highest (P \u3c 0.05) levels of catecholamines with respective epinephrine, norepinephrine and dopamine concentrations of 10.8, 9.7 and 14.8 nmol/mmol. Nguni steers had the lowest (P \u3c 0.05) levels of catecholamines, with respective catecholamine concentrations of 5.1, 4.3 and 4.0 nmol/mmol. In the Nguni steers, there were significant (P \u3c 0.05) correlations between catecholamines and L* and between dopamine and tenderness in meat aged for two days (WBSF2). In the Bonsmara, dopamine was correlated (P \u3c 0.05) pHu, WBSF2 and CL. No significant correlations were found in the Angus. Therefore the relationship between stress responsiveness and certain beef quality traits may not be similar in different breeds

Assessing the nutritional status of beef cattle: current practices and future prospects

Accurate determination of nutritional and health status of animals is invaluable in modern animalagriculture. Body weights and body condition scoring are the commonly used methods of assessingnutritional status of animals. This paper discusses drawbacks these methods have and highlights thebenefits for using blood metabolites in assessing nutritional status of beef cattle. Blood metabolitelevels indicate the extent of metabolism of energy, proteins and other nutrients in animals. Glucose,cholesterol, non-esterified fatty acids, protein, urea, creatinine, albumin, globulin, minerals, liverenzymes and haematology can be used objectively, reliably and routinely to assess the nutritionalstatus of cattle. In Southern Africa, the use of these metabolites is rare due to lack of equipment forblood analysis and the high cost of analyzing the blood parameters. However, use of high value Ngunicattle in Southern Africa requires the use of blood parameters to accurately assess their nutritionalstatus. Several factors, such as physiological status of an animal, breed, nutrition, season and ageaffect levels of blood metabolites. Combining body weights, body condition scores and bloodmetabolites increase accuracy of assessing the nutritional state and welfare of beef cattle