No abstract

Southern Africa is home to over 64 million cattle, of which 75% are raised on natural pasture in smallholder farming areas. Indigenous cattle breeds Bos indicus (zebu), B. taurus africanus (Sanga type) and their crosses with B. taurus (European and British) are the most dominant. Despite their dominance, indigenous cattle breeds in smallholder farming areas are commonly marketed through informal markets, and their contribution to formal national economies is therefore limited. This is partly because the current beef carcass grading and classification systems used in the region value inappropriately carcasses from slow-maturing indigenous cattle breeds that are ideally suited to being marketed off natural pasture. The existing systems use carcass yield and quality attributes, but do not predict eating quality at consumer level. Moreover, the principal criteria used to estimate carcass yield and quality, namely age, fat cover and conformation, are assessed indirectly and subjectively. The objective of the current review is to provide an overview of beef carcass grading and classification systems in Southern Africa and analyse their shortcomings in valuing carcasses from indigenous breeds and local production systems. In addition, the review highlights opportunities for improving these systems in Southern Africa and makes suggestions towards developing a regional beef carcass classification system.

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.