Utility of Acacia karroo for beef production in Southern African smallholder farming systems: A review

Significance of sesame (Sesamum indicum L.) as a feed resource towards small-ruminant animal production in Southern Africa: a review

Sesamum indicum (sesame) is a small seed legume, which is of nutritional and medicinal value to livestock. Sesame is a legume with positive attributes that include drought tolerance (owing to its extensive rooting system), low input demand for growth, and reduction of soil nematodes (in crop rotation systems). Attention in research has been shifted towards usage of sesame as human food to exploitation as livestock feed because of its high levels in crude protein (CP), minerals, amino acids, and polyunsaturated fatty acids (PUFAs). However, it is underutilized as a livestock feed resource in Southern Africa. In recent years, there has been increasing interest to cultivate the crop in Southern African countries through non-governmental organizations (NGOs) initiatives. The focus of such initiatives has been mainly production without value addition of the seed. At present in Southern Africa, widespread adoption of feeding strategies based on sesame has been restricted mainly due to lack of knowledge on production, marketing and value addition, availability of the seed, and technology adoption. Technology adoption is often limited specifically when oil extraction is considered, where by-products such as the meal are useful in animal production. This paper reviews the potential use of sesame to improve growth rates, feed intake, carcass qualities, meat quality, milk quality, milk yield, and blood metabolite levels of small ruminants. Production potential, economic feasibility, and strategies of using sesame in small-ruminant feeding programs are also outlined.

The Potential Effect of Dietary Tannins on Enteric Methane Emission and Ruminant Production, as an Alternative to Antibiotic Feed Additives – A Review

Antibiotic growth promoters in livestock nutrition cause microbial resistance which produces threats to human health. Therefore, tannins have been considered as natural alternative antibiotic feed additives which possess various biological properties including antimicrobial, anti-inflammatory, antioxidant and immunomodulatory. Additionally, these plants also have antiparasitic and anti-bloat characteristics which contribute to inhibit the enteric methane emission in order to improve nutrient digestibility, milk and meat quality, fatty acids composition and ruminant production. Antibiotic growth promoters have been practiced in animals feeding to increase feed intake, growth rate, weight gain as well as reduce metabolic disorders and energy losses in the rumen. In 2006, the European Union banned the usage of antibiotic growth promoters in the feeding of livestock. This antibiotic resistance issue has increased demand to explore the natural feed additives that might be useful for animal production system. Consequently, natural forages have been categorized as potential feed additives in animal production since it improves nutritive value, protein digestibility, increase amino acid absorption and growth rate. But, some plant materials are usually rich in tannins known as anti-nutritional factors. Therefore, the application of tannin-rich plants in ruminant nutrition needs great precaution due to its possible injurious effects (dose dependent) on animal health such as metabolic disorders. Hence, there is need to give attention to the usage of tannins in ruminant nutrition as an alternative to antibiotics feed additives to investigate its effects on enteric methane emissions and ruminants production. In addition, safety and risk associated with tannins feeding have also been briefly discussed.

Strategies for Sustainable Use of Indigenous Cattle Genetic Resources in Southern Africa

Indigenous cattle breeds are the most important livestock species in the Southern African Development Community (SADC) region owing to their role in human food, nutrition, income, and social security. Despite the role of these breeds in the household and national economies, they are currently underutilised, their productivity remains low, and populations are faced with extinction. In addition, there are insufficient measures taken to secure their present and future value. The current review highlights strategies for sustainable use of indigenous cattle genetic resources in the region, including the use of novel production and marketing practices, women and youth empowerment, and development of the appropriate capacity building, legislative, and policy structures. At present, the lack of coordination among the different stakeholders still poses a challenge to the implementation of these strategies. To this end, partnerships, collaboration, and stakeholders’ participation are recommended to effectively implement strategies for sustainable use of indigenous cattle breeds.

Intake, digestibility, rumen protein synthesis, and growth performance of Malawi Zebu steers fed diets containing rangeland-based protein sources

The study evaluated effects of feeding Malawi Zebu steers with diets containing baobab (Adansonia digitata) seed meal and white thorn tree (Vachellia polyacantha) leaf-meal as alternative protein sources to soybean meal on dry matter intake (DMI), total tract nutrient digestibility, rumen microbial nitrogen supply and growth performance. Thirty Malawi Zebu steers (181 ± 21.4 kg and 29 months), put into individual pens, were randomly assigned to three treatments (10 steers per treatment) made up of rangeland hay and maize bran with either baobab seed meal (baobab diet), V. polyacantha leaf-meal (Vachellia diet), or soybean meal (soybean diet, control) as the protein source. Steers fed the soybean and baobab diets had higher (P ≤ 0.05) DMI, final BW, average daily gain (ADG), and total tract nutrient digestibility of DM, NDF, CP and crude fat than those fed the Vachellia diet. Steers fed the soybean diet had the highest feed conversion ratio followed by those fed the baobab and Vachellia diets, respectively (P ≤ 0.05). Steers fed the baobab diet had the highest rumen microbial N followed by the soybean- and Vachellia-fed steers in that order (P ≤ 0.05). Steers fed the baobab diet had higher microbial N supply, comparable DMI, ADG, FCR, and nutrient digestibility to the soybean diet. The baobab seed meal could be an alternative protein source to the soybean meal for beef production in Malawi.

Effect of polyethylene glycol 4000 supplementation on the performance of yearling male Pedi goats fed dietary mixture levels of Acacia karroo leaf meal and Setaria verticillata grass hay

Eighteen yearling male Pedi goats weighing 21.7 ± 3.1 kg were used in a 42-day trial in a 2 (Acacia karroo leaf meal levels) × 3 (levels of PEG 4000) factorial arrangement in a completely randomized design to determine PEG 4000 supplementation levels for optimal productivity of indigenous Pedi goats fed different mixture levels of A. karroo leaf meal and Setaria verticillata (L.) P.Beauv. grass hay. Each goat was supplemented with 0, 23 or 30 g of PEG 4000 per day in addition to dietary mixture of A. karroo and S. verticillata hay. Polyethylene glycol 4000 supplementation had no effect (P > 0.05) on nutrient intake of goats. However, a diet × PEG (P < 0.05) was observed for intake of all nutrients studied. Dry matter, OM, NDF and ADF intakes per goat were optimized at PEG 4000 supplementation levels of 19.62, 19.62, 19.61 and 19.53 g/goat/day, respectively, for diets containing 20% A. karroo leaf meal. Polyethylene glycol 4000 supplementation had no effect (P > 0.05) on the apparent digestibility of all nutrients. The dietary inclusion level of A. karroo leaf meal at 20% improved (P < 0.05) DM, OM, CP, NDF and ADF digestibility of goats. Crude protein digestibility was optimized at a PEG 4000 supplementation level of 15.78 g/goat/day. Dietary mixture level and PEG 4000 supplementation had no effect (P > 0.05) on final weights of Pedi goats. Similar results were observed for blood urea and glucose concentrations of yearling male Pedi goats. However, daily body weight gain was higher (P < 0.05) in goats fed 50% A. karroo leaf meal than those on 20% inclusion level. Polyethylene glycol 4000 has potential to improve the feeding value of tanninifeorus A. karroo leaf meal.

Acacia karroo Hayne: Ethnomedicinal uses, phytochemistry and pharmacology of an important medicinal plant in southern Africa

Acacia karroo (A. karroo) has been used as herbal medicine by the indigenous people of southern Africa for several centuries. The potential of A. karroo as herbal medicine, its associated phytochemistry and biological activities are reviewed. The extensive literature survey revealed that A. karroo is traditionally used to treat or manage 32 and five human and animal diseases and ailments, respectively. The species is used as herbal medicine for diseases and ailments such as colds, diarrhoea, dysentery, flu, malaria, sexually transmitted infections (STIs), wounds, and also as colic and ethnoveterinary medicine. Multiple classes of phytochemicals such as flavonoids, phenols, phytosterols, proanthocyanidin, tannin, terpenes as well as several minerals have been identified from leaves and roots of A. karroo. Scientific studies on A. karroo indicate that it has a wide range of pharmacological activities which include antibacterial, antifungal, antigonococcal, antihelmintic, antilisterial, antimalarial, antimycobacterial, antioxidant, HIV-1 reverse transcriptase, anti-inflammatory and analgesic. A. karroo has a lot of potential as a possible source of pharmaceutical products for the treatment of a wide range of both human and animal diseases and ailments. Future research should focus on the mechanisms of action of the different plant parts used as herbal medicines, isolated compounds, their efficacy, toxicity and clinical relevance.

Influence of Acacia tortilis leaf meal-based diet on serum biochemistry, carcass characteristics and internal organs of finishing pigs

Dietary inclusion of tannin-rich leguminous leaf meals beyond threshold levels can impose toxicity and compromise welfare of pigs. The objective of the study was to determine the response of metabolites, carcass characteristics and internal organs of finishing pigs to Acacia tortilis leaf meal inclusion levels. Thirty Large White × Landrace pigs (61.6 ± 1.23 kg bodyweight) were randomly allotted to six dietary treatments, to give five replicates per treatment. The treatments contained 0, 50, 100, 150, 200 and 250 g/kg of A. tortilis leaf meal and were rendered iso-energetic and iso-nitrogenous. An increase in A. tortilis inclusion was related to an initial increase and then a decrease in feed intake (P < 0.05), weight gain (P < 0.001) and feed conversion ratio (P < 0.05). Serum concentrations of iron and activities of aspartate aminotransferase and alkaline phosphatases increased quadratically (P < 0.001) as A. tortilis leaf meal increased. There was a significant linear increase in alanine aminotransferase activity with leaf meal incremental level. Hepatosomatic index, scaled kidney weight and scaled heart weight increased linearly (P < 0.001) as A. tortilis increased. There was a quadratic increase in the relative weight of lungs (P < 0.001) as leaf meal increased. Although quadratic decreases (P < 0.01) in cold-dressed mass and dressing percentage were observed with incremental levels of A. tortilis leaf meal, there was a linear decrease (P < 0.05) in backfat thickness. It was concluded that serum biochemistry, internal organs and carcass characteristics respond differently to increases in A. tortilis inclusion. The A. tortilis leaf meal can be supplemented in finishing pig diets at low levels before feed efficiency and carcass characteristics are negatively affected.

Feed intake and growth performance of growing pigs fed on Acacia tortilis leaf meal treated with polyethylene glycol

The objective of the study was to determine the response in feed intake and performance of pigs fed on incremental levels of polyethylene glycol (PEG). Forty-eighty male F1 hybrid pigs were randomly allotted to six diets containing 0, 5, 10, 15, 20, and 25 g/kg of PEG, respectively. Acacia tortilis leaf meal was included at a rate of 150 g/kg. Each diet was offered ad libitum to eight pigs in individual pens. Average daily feed intake (ADFI), scaled feed intake (SFI), average daily gain (ADG), and gain to feed ratio (G:F) were determined weekly. The ADG showed a linear response to PEG (p < 0.01). The linear regression equation was y = 0.0061x + 0.6052 (R(2) = 0.64). There was a quadratic response to PEG on ADFI, and SFI (p < 0.01) and G:F (p > 0.05). The regression equations and R(2) values were as follows: ADFI y = 0.0008x(2) - 00086x + 1.2339 (R(2) = 0.96), SFI y = 0.0147x(2) - 0.2349x + 40.096 (R(2) = 0.95), and G:F ratio y = 0.0002x(2) - 0.0017x + 0.5168 (R(2) = 0.56). The ADFI, SFI, and ADG increased as weeks of feeding progressed (p < 0.01), but the G:F ratio decreased as weeks increased. It can be concluded that the relationship between PEG inclusion and performance of growing pigs fed on A. tortilis is exponential, rather than linear. The economic benefit of using PEG depend on cost of labor, availability of Acacia, costs of harvesting together with processing, and acceptability of the pork.

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).

Non chemical control of helminths in ruminants: adapting solutions for changing worms in a changing world

Infections with gastrointestinal nematodes (GIN) remain a major threat for ruminant production, health and welfare associated with outdoor breeding. The control of these helminth parasites has relied on the strategic or tactical use of chemical anthelmintic (AH) drugs. However, the expanding development and diffusion of anthelmintic resistance in nematode populations imposes the need to explore and validate novel solutions (or to re-discover old knowledge) for a more sustainable control of GIN. The different solutions refer to three main principles of action. The first one is to limit the contact between the hosts and the infective larvae in the field through grazing management methods. The latter were described since the 1970s and, at present, they benefit from innovations based on computer models. Several biological control agents have also been studied in the last three decades as potential tools to reduce the infective larvae in the field. The second principle aims at improving the host response against GIN infections relying on the genetic selection between or within breeds of sheep or goats, crossbreeding of resistant and susceptible breeds and/or the manipulation of nutrition. These approaches may benefit from a better understanding of the potential underlying mechanisms, in particular in regard of the host immune response against the worms. The third principle is the control of GIN based on non-conventional AH materials (plant or mineral compounds). Worldwide studies show that non conventional AH materials can eliminate worms and/or negatively affect the parasite's biology. The recent developments and pros and cons concerning these various options are discussed. Last, some results are presented which illustrate how the integration of these different solutions can be efficient and applicable in different systems of production and/or epidemiological conditions. The integration of different control tools seems to be a pre-requisite for the sustainable management of GIN infections. This new era of GIN management requires a new paradigm: to achieve enough control to reduce the negative impact of GIN infections enabling an optimum level of production, health and welfare.