Broiler lameness (syn. leg weakness) is a cause of commercial loss through mortality, culling and reduced performance and is a welfare concern both within and outside the broiler industry. Many of the cases of lameness are associated with infection in bone, joint or integument. Several groups of organisms have the potential to cause disease resulting in lameness, but the most common causes are restricted to a small group of infectious organisms. These bacterial, viral and fungal infections and their associated pathologies are systematically described.

This review focuses on recent progress on the functions of choline and betaine and on the interactions between these two methyl donors and methionine chickens (mainly), pigs, fish (and crustaceans). When chickens receive a diet marginally deficient in methionine, supplementation with choline or betaine does not generally induce a return to the maximum growth rate. In this species betaine potentiates submaximal doses of some anticoccidial compounds, most probably through its osmolytic property. The ‘slimming’ effect which has been observed for betaine in a few assays with chickens and pigs has not been confirmed in several other species and therefore remains to be unequivocally demonstrated. In fish there is a need for phospholipids during the early stages of development. In salmonidae some studies suggest that betaine may facilitate the adaptation to sea water.

The review presents information on non-starch polysaccharides (NSPs), the major antinutritive factors found in cereals and a variety of other feed ingredients. The unique characteristics of these compounds and their effects on the utilisation of other dietary components are highlighted. The effects of NSP on the gross weight of the gastrointestinal tract, mucosal structure and function are examined and some reference is made to other species on which more research has been conducted. More research is required into the effects of NSPs on the integrity of the intestinal mucosa in poultry. Such information may assist in the development of breeding and management strategies to reduce the effects of NSPs.

Ostrich meat may be consumed as a healthy alternative to beef. The establishment of ostrich farming systems is not sufficient to satisfy consumer demand without the use of a successful production and marketing strategy. Given the current export driven nature of the industry in Southern Africa and the need for the development of a domestic market, a good understanding of the position of ostrich meat in the marketing mix and the key elements in meat processing is necessary.

The effects of ante-mortem stressors such as stunning, struggling, environmental temperature and feed withdrawal on the biochemical changes of broiler breast muscle are assessed in relation to post-mortem biochemical changes and the subsequent tenderness of broiler breast meat. The findings of investigations concerned with broiler meat are presented alongside more fundamental studies addressing such aspects as Ca2+ release and sequestration, endocrine changes during periods of stress and the role of fatty acids as regulators of membrane bound channels. An attempt is made to assimilate the pertinent facts associated with this topic and to give directions for future research. It is concluded, however, that, whilst tenderness in meat is often associated with a loss of ATP, glycogen breakdown and lactic acid accumulation within muscles, current data are insufficient to enable a definitive decision to be made as to which have adverse effects on broiler meat tenderness.