Dynamics and influence of environmental components on greenhouse gas emissions in sub-Saharan African rangelands: a review

Sub-Saharan African (SSA) countries consist of ~200 million livestock owners who utilise marginal rangelands as a feed resource base for their animals. These rangelands offer various resources to the communities and are in-turn vulnerable to climate change related challenges. Currently, information on greenhouse gases (GHG) emission from SSA rangelands is heavily dependent on the generic values generated by the Intergovernmental Panel on Climate Change (IPCC) Tier I trajectories on various aspects of the environment. There is, therefore, a need to identify research gaps between the dynamics and influences of environmental components, highlight their magnitude and potential aggregate contribution towards GHG emission in an SSA context. Rangeland sustainability, weather patterns, soils, plant biodiversity, and current methods used to measure GHG emission from rangelands are influenced by institutional, community, and national policy frameworks. Various intertwined environmental components exist within the SSA rangeland ecosystems and research has not extensively covered such interactions. It is crucial to generate a database that includes information of in-situ trajectories on GHG emission from soil properties, vegetation image maps using remote sensing and geographic information system, plant biodiversity indices, climatology, and animal husbandry aspects.

Fermented meat sausages from game and venison: what are the opportunities and limitations?

An increase in the acceptance, demand and production of game meat and venison has been experienced globally. Game meat and venison fit into consumers' ideology of healthy and environmentally friendly meat when compared to domesticated animals. Opportunities exist to explore the use of these meat sources in developing new products, particularly as game meat and venison in their fresh state are sometimes perceived as being tough. Consumers have shown a trend for trying exciting new products with different organoleptic qualities, and fermented sausages occupy a special niche in the gastro-economic trade. In this review, the production potential of game meat and venison and its prospective use in the development of fermented sausages are discussed. Emphasis is placed on the importance of meat characteristics in textural and sensorial development as well as the safety of fermented sausages. Additionally, consumers' perception of venison and game meat is discussed. Possible areas of research and knowledge gaps are highlighted, particularly the potential use of meat with high pH and microbial load. © 2018 Society of Chemical Industry.

Prevalence and seasonal variation of gastrointestinal nematodes and coccidia infecting ovine grazing on communal rangelands in the Eastern Cape, South Africa

Nematodes and coccidia are major pathogens causing parasitic infections in livestock production. This study aimed to determine the prevalence and seasonality of gastrointestinal helminths and coccidia in communal sheep grazing in humid, semi-humid and arid zones of the Eastern Cape Province. A total of 3299 faecal samples were collected from sheep between January 2012 and December 2015. Of the collected roundworm species (faecal eggs and faecal cultures), Haemonchus contortus was the only species found. The prevalence of gastrointestinal parasites was significantly higher in the humid zone (H. contortus 81% and coccidia 37%), followed by a semi-humid zone (H. contortus 75% and coccidia 22%) and the arid zone was the lowest (H. contortus 71% and coccidia 14%). Haemonchus contortus had significantly higher faecal egg counts (FEC) during spring (1465.73 ± 143.56) and summer (1418.73 ± 160.73) and the lowest during autumn (496.67 ± 219.13) and winter (352.05 ± 164.44) in all agro-ecological zone. The humid zone had significantly higher FEC in seasonal occurrence of H. contortus and coccidia compared with other agro-ecological zones (P < 0.05). There was no significant difference (P > 0.05) observed in the seasonal occurrence of H. contortus species in arid zone. Surprisingly, higher coccidia counts (352.17 ± 43.58) during 2012 winter season in humid zone and in summer season (0.00 ± 559.72) of 2013 in the semi-humid zone than other agro-ecological zones. However, agro-ecological zone differences and seasonal variations had an influence on H. contortus and coccidia distribution and abundance. This study confirms that helminths and coccidia are major causative agents causing parasitic infections in livestock production, and therefore, good animal health management practices including proper hygiene should be followed to prevent parasitic infection in small ruminants.

Biochemical indices and heamtological parameters of goats fed lablab purpureus and vigna unguiculata as supplements to a chloris gayana basal diet

The objective of this study was to evaluate the effects of forage legume diets on haematological and biochemical indices of Xhosa goats. Eighteen animals, one-year-old, of average live weight 14.13 ± 0.24 kg were assigned, in a completely randomized design, to three treatment diets. Animals were housed individually and sex was equally represented among treatments with 6 animals per treatment. Weights and blood samples were taken every fortnight. A pair of blood samples (5 ml each) were collected from each goat, via jugular vein puncture and were subjected to either haematological or biochemical analysis. The results show that treatment diets and sex significantly (P < 0.05) affected DMI, total gain, ADG, and feed conversion ratio. Treatment diets and sex had no effects (P > 0.05) on serum total proteins, globulins, urea, creatinine, alanine aminotransferase, alkaline phosphatase (ALP), and gamma- glutamyl transferase concentrations. The diet influenced albumin was (P < 0.05) while sex influenced ALP concentration (P < 0.05). Measured over time, the plasma concentration of urea and ALP significantly increased (P < 0.05) while creatinine and cholesterol concentration decreased (P < 0.05). Although the overall blood biochemical properties remain unchanged among the treatments and between sexes; treatment by sex, treatment by day and sex by day interactions were significant (P < 0.05). The white blood cells, red blood cell, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, haemoglobin, haematocrit, and platelet and mean platelet volume levels were similar among treatments and between sexes (P > 0.05). The mean cell volume and red cell distribution width were different among treatments (P < 0.05). Treatment diets significantly (P < 0.05) influenced neutrophil (%) content while sex influenced basophile (%) content. In conclusion forage legumes did not cause toxicity in goats or any pathological condition.

In vitro efficacy of Elephantorrhiza elephantina root extracts against adult Paramphistomum cervi in goats

Elephantorrhiza elephantina is a medicinally important plant whose roots are used to control gastrointestinal parasites in goats. The use of plant-based anthelmintics as potential alternatives to synthetic anthelmintics in controlling gastrointestinal worms in ruminants is a promising area of research. The study was carried out to ascertain the efficacy of E. elephantina in controlling goat trematodes. Standard procedures were used to quantify the phytochemicals in the water, ethanol and methanol root extracts of E. elephantina. The quantitative phytochemical analysis revealed that alkaloids (93.24 ± 1.68%), condensed tannins (450.52 ± 0.15 mg CE/g), flavonoids (803.93 ± 0.13 mg QE/g), phenols (476.11 ± 0.37 mg GAE/g) and saponins (83.28 ± 1.72%) were present in E. elephantina root extracts. Paramphistomum cervi adult worms recovered from the rumen of freshly slaughtered goats were used. In vitro screening of ethanol, methanol and water extracts of E. elephantina for potential anthelmintic activity against adult P. cervi worm motility showed time and dose-dependent significant effects. Ethanol extracts showed a highly significant (P < 0.05) inhibition of motility (86.67 and 96.67%) at concentrations 7.5 and 15 mg/mL respectively, after 12 h of treatment, while methanol and water extracts exhibited a significant (P < 0.05) inhibition of motility (96.67 and 66.67% respectively) at concentration of 15 mg/mL 16 h post-exposure. Our findings confirm the efficacy of E. elephantina in controlling goat trematodes.

An outlook on livestock welfare conditions in African communities - A review

A significant proportion of the African continent is conducive for animal agricultural production, due to its historical experience and available resources to accommodate and nurture various indigenous and exotic animal species and breeds. With food security being a global challenge, animal products can play an important role as nutrient dense food sources in human diets, particularly in Africa. However, this does not seem to reach its full potential in practice, due to numerous reasons that have not been adequately addressed. Animal welfare reservations can be highlighted as one of the major contributing factors to the curbed progress. The consequences have been scientifically proven to affect product quality and market access. However, in the African community, the concept of animal welfare has not been fully embraced. While there are international animal welfare standards in the developed world, there are inherent factors that hinder adoption of such initiatives in most developing regions, particularly among communal farmers. These include cultural norms and practices, social ranking, socio-economic status, available resources, information dissemination and monitoring tools. Therefore, there is need to harmonize what is internationally required and what is feasible to accommodate global variability. The protocols followed to ensure and evaluate farm animal welfare require regular investigation, innovation and a sustainable approach to enhance animal productivity, efficiency and product quality. Additionally, investing in animal wellbeing and health, as well as empowering communities with significant knowledge, has a potential to improve African livelihoods and contribute to food security. This review seeks to highlight the concept of animal welfare in relation to livestock and food production in African conditions.

Behavioral and Haemato-Biochemical Responses of Nguni and Boran Steers Post Relocation and Herd Regrouping in a Novel Environment

Behavioural and blood-based physiological responses of Nguni (NG) and Boran (BR) steers, following relocation to a new environment and herd regrouping were examined. Ten steers of each genotype aged 9 months and reared under similar conditions were studied over 16 weeks: 1 for acclimatization and baseline measurements in original groups, 15 for post regrouping measurements. Each sampling week, direct visual observations and durations of aggressive and affiliative interactions were recorded between 0500-1900h for 3 conservative days. Blood samples were drawn fortnightly by jugular venipuncture for plasma cortisol, glucose, creatine kinase (CK) and haematological analysis. In weeks 1-5, BR had higher instances of head-butting (P=0.0311), mounts (P=0.0142) and threats (P=0.0241) compared to NG (P<0.0001, P=0.0412 and P=0.0241, respectively). However, these significantly declined from weeks 7-15 in both genotypes. Grooming increased consistently over the weeks in both genotypes (P=0.0214). Head-butting correlated with cortisol (r=-0.116), CK (r=-0.295) and neutrophil-to-lymphocyte ratio (r=-0.144). Grooming correlated (r=0.137) with white-blood-cell-count. Herd regrouping temporarily disrupted social behaviour, with BR showing more aggression towards NG steers. Nevertheless, the two genotypes established some stability within five weeks of social mixing.

Meat quality, fatty acid profile, and sensory attributes of spent laying hens fed expeller press canola meal or a conventional diet

This study evaluated the effects of feeding an expeller press canola meal (EPCM) supplement (20%) on the carcass, meat, and sensory quality characteristics of spent laying hens. Thirty EPCM-based and thirty conventionally (soybean based) fed Lohmann Brown-Elite spent laying hens were obtained from a commercial egg farm. Carcass, portions, physical quality, proximate composition, fatty acids, and sensory quality were determined. EPCM-fed hens had higher (P ≤ 0.05) drum yield, breast bone weights and percentages, but lower (P ≤ 0.05) thigh and breast meat yields. Conventionally fed hens had higher (P ≤ 0.05) thaw losses, skin yellowness (b*), Chroma values and breast fat content with lower (P ≤ 0.05) cooking losses, skin redness (a*) and hue angle values, as well as breast Warner-Bratzler shear force values (N) (15.43 ± 0.600 vs. 12.37 ± 0.411). Palmitic acid, stearic acid, heneicosanoic acid, palmitoleic acid, saturated fatty acids (SFA) (34.0 ± 0.56 vs. 38.7 ± 0.71), n-6:n-3 polyunsaturated fatty acids (PUFA) ratio (5.5 ± 0.13 vs. 7.2 ± 0.28), atherogenic index, thrombogenic index, delta-5 desaturase, elongase index, and thiosterase index were lower (P ≤ 0.05) for EPCM-fed hen breast meat. Myristic acid, lignoceric acid, nervonic acid, alpha-linolenic acid, docosahexaenoic acid (DHA), PUFA:SFA ratio (0.7 ± 0.05 vs. 0.9 ± 0.02), n-3 PUFA (3.4 ± 0.31 vs. 5.1 ± 0.17), hypocholesterolemic:Hypercholesterolaemic, stearoyl-CoA desaturase 16, and stearoyl-CoA desaturase 18 were higher (P ≤ 0.05) for EPCM-fed hen breast meat. Metallic flavor was decreased (P ≤ 0.05) for EPCM-fed hen breast meat. Generally, effects of EPCM supplementation were observed to have an effect on the carcass, physical quality, proximate composition, fatty acids, and health indices. The sensory profiles did not differ between EPCM and conventionally fed spent laying hen breast meat (except for metallic flavor). The EPCM improved the nutritional profile of spent laying hen meat with low intramuscular fat, low n-6:n-3 PUFA ratio, and favorable lipid health indices.

Effects of feeding increasing levels of grape (Vitis vinifera cv. Pinotage) pomace on lamb shelf-life and eating quality

The study evaluated shelf-life and sensory quality of meat from lambs fed finisher diets containing increasing levels of grape pomace (GP; 0, 5, 10, 15 and 20% GP/kg DM). Color, antioxidant activity and lipid oxidation of the longissimus lumborum were evaluated on different storage times (days 1, 3, 5, 7 and 9) post-slaughter using overwrapped air-permeable packaging. Treatments 0, 10 and 20% GP/kg DM were used for evaluation of protein oxidation and microbial counts on days 1, 5 and 7, while a trained panel assessed the sensory quality on day 1. Diet neither influenced meat color nor sensory quality. Diet × day interactions were observed for antioxidant activity, lipid and protein oxidation. Overall, the 20% GP/kg-diet finished lamb meat had the highest antioxidant activity and the lowest total viable bacterial counts, lipid and protein oxidation values during the shelf-life period. The 20% GP/kg DM in lamb diets, therefore, improved lamb meat shelf-life without negatively affecting sensory quality.

Influence of drying technique on chemical composition and ruminal degradability of subtropical Cajanus cajan L

The experiment investigated the influence of forage drying methods on the dry-matter digestibility of foliage from Cajanus cajan varieties (ICEAP 00557, ICEAP 01514 and CIMMYT100/01). These leaves were harvested at week 20 of growth and either oven- or shade-dried and analysed for chemical components and rumen degradability. Three rumen fistulated lactating Holstein cows (430 ± 18 kg live weight) were used to evaluate ruminal degradation kinetics using in vitro and in sacco procedures. Samples were incubated for 0, 4, 8, 12, 24, 30 and 48 h in vitro (IV DaisyII) procedure. In the in sacco procedure, samples were incubated for 0, 4, 8, 12, 24, 30 and 48 h in the rumen of cows. Dry matter disappearance (DMD) data for both measures were fitted to the equation Y = a + b (1 - e -ct ), where b is the slowly degradable fraction and c is the degradation rate constant, to approximate rumen degradability characteristics of varieties. Shade dried leaves contained higher crude protein (CP) (P < 0.05) than oven dried leaves. Oven drying method increased (P < 0.05) neutral detergent insoluble nitrogen (NDIN) and acid detergent insoluble nitrogen (ADIN) content of varieties. However, shade drying method gave the higher concentration of NDIN and ADIN. Drying technique had no effect (P > 0.05) on ash, neutral detergent fiber (NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL) of varieties. Drying method did not affect (P > 0.05) calcium (Ca) and phosphorus (P) concentration in the forage dry matter. Drying method had no effect (P > 0.05) on b and c of all varieties during in vitro procedure. However, shade-drying method increased (P < 0.05) b and c of all varieties during in sacco procedure. It was concluded that shade-drying, in contrast to oven-drying, would be the most suitable method as it improves the nutritive value of the forage for ruminants.

Molecular characterisation of antibiotic-resistant Salmonella enterica isolates recovered from meat in South Africa

Salmonella enterica is a leading cause of human gastroenteritis in both developed and developing countries, causing significant economic losses on humans and animals worldwide. There are several routes for contracting salmonellosis, but the consumption of contaminated foods is by far the most frequent cause of human infections. This study aimed to assess the prevalence and resistance determinants of S. enterica isolates obtained from meat. Swab samples from meat were cultured for the identification of Salmonella spp., and 239 presumptive S. enterica isolates were recovered, purified and kept in glycerol stocks. The S. enterica. confirmed by polymerase chain reaction (PCR) were further tested against 15 antimicrobials using the disc-diffusion method on Muller-Hinton agar and the genotypic antimicrobial resistance determinants by PCR. Resistance among tetracyclines, bêta-lactams, and 3rd generation cephalosporins was found to be most frequent with a noticeable rise in the number of multi-drug resistance ranging from two to seven antimicrobials. A total of 20 resistance determinants were assessed with their prevalence and distributions obtained as follows; [aminoglycosides: aadA (89%), aacC2 (100%), aphA1 (38%), aphA2 (0%) and strA (7%)], [β-lactams: (ampC 100%), blaTEM, (33%), blaZ (17%) and blaOXA (10%)], [Chloramphenicol: catI (9%), catII (7%), and cmIA1 (10%)] and [tetracyclines: tetA (57%), tetB (30%), tetC (11%), tetD (73%), tetK (20%) and tetM, (43%)], and [sulfonamides: sulI (82%), sulII (7%)]. The findings signify a high prevalence of multidrug-resistant (MDR) S. enterica isolates and resistance determinants indicating increased public health risks associated with the consumption of contaminated meat.