Haemorrhages in the muscles of broiler chickens are major quality defects which occur in all types of muscles and muscle parts. They are closely related to muscle injury and can be the result of trauma, strenuous muscle activity, exposure to extreme environmental conditions, restraining and electrical stunning. In this review the different types of haemorrhages are classified. A brief introduction on muscle morphology and blood supply is given to discuss the mechanisms that may cause haemorrhages and a survey of these mechanisms is presented. Some of the mechanisms, together with factors likely to affect the susceptibility of chickens to haemorrhages, are discussed in relation to rearing, transport, slaughter and processing of broiler chickens.

Modern fowl breeder production has resulted in a wide disparity between the environment, mating behaviour and morphology of modern breeds in comparison with progenitor species. The environment is strictly controlled in most respects and dim lighting is maintained with luminaires that were originally designed for humans and that differ substantially in terms of intensity and colour balance from natural daylight. The elaborate mating displays observed in feral poultry and red jungle fowl rarely, if ever, occur in breeder houses. In most avian species females choose the males, whereas cockerels in breeder houses often appear to mate forcibly and aggressively with hens in the absence of any assessment by the hen. Cockerel and hen breeder fowl also differ morphologically from their progenitor species through genetic selection (larger and heavier) or mutilations (dubbing, etc). Given the apparently large differences between the subtle, gradually evolved mating ‘ecology’ found naturally and the production environments found commercially, it is perhaps surprising that little consideration has been given to this disparity in modern breeder production environments. An understanding of the factors governing choice of mate in commercial breeder houses and the influence of the visual environment may highlight novel methods whereby efficiency of these enterprises can be improved and elements of the welfare of breeder fowl assessed.

An important objective of the least cost formulation of broiler diets is to provide sufficient amounts of the most limiting amino acids to support the needs of tissue maintenance and accretion while minimising any excesses. Threonine is the third most limiting amino acid in broiler diets behind the total sulphur-containing amino acids and lysine. Research into the threonine requirement of broilers is sparse compared with that of methionine and lysine. However, recent work on the threonine needs of growing and finishing broilers has been invaluable in helping commercial nutritionists determine the minimum amount of threonine required in least cost diet formulations. This review summarises this recent research. It also considers threonine needs for optimal immune system functions, feather growth, glycine requirements and gastrointestinal functions, as well as under conditions causing heat stress.

A total of 215 indigenous chickens were found in 10 homesteads visited in Oodi, Kgatleng, Botswana from June to July 1999. The mean (SD) flock size was 21.5 (11.6) with a range of 7–47. The chickens were not housed but instead spent the night on top of trees to escape predation. Vaccinations against poultry diseases such as Newcastle disease were not carried out. Instead, traditional herbal remedies were used to treat sick chickens. Only a few adult birds were infested with scaly leg mites and fleas. Worm eggs were not detected in faecal samples examined but some coccidial oocysts were seen. Antibodies to avian infectious bronchitis, infectious bursa1 disease, Mycoplasma gallisepticum and egg drop syndrome were demonstrated in some of these chickens, suggesting previous infections or exposure.

Capillaria contorta is a parasitic nematode of the oesophagus and crop of a number of domestic and wild birds. This study deals with three cases of capillariasis in the red-legged partridge. Infected individuals in two of these cases presented a history of weight loss, weakness, feather alterations and death, while morbidity and mortality were limited. In the third case, deaths occurred only after the birds were freed for repopulation purposes. Congestion of the crop was seen at necropsy. Histological examination revealed the presence of parasites and their eggs in the epithelium of the oesophagus and crop of every partridge. The worms displayed a characteristic distribution in all three cases: adults were found in the basal portion of the epithelium while the eggs were located in the middle. In one bird, parasites were observed in the anterior segment of the proventriculus. The fundamental epithelial lesion consisted of spongiosis of the oesophagus and crop. In the individual with proventricular parasitism, epidermoid metaplasia was also seen. The inflammatory reaction observed in the lamina propria was discrete and diffuse, except in those cases in which epithelial necrosis and bacterial colonies were detected.