The weight of hatching eggs can influence broiler live performance regardless of hen age. Egg composition is altered with egg weight, but such alterations do not seem to have major effects on broiler growth and processing yields. The chick hatches with a yolk sac which provides nutrients for the transition to independent feeding. Alterations in egg weight and composition do not affect the proportion of yolk sac to body weight as much as its composition, particularly with eggs from very young hens. The contents of the yolk sac are high in fat and protein but very low in carbohydrate, which could lead to ketosis with prolonged fasting. Enhancing the first feed with either carbohydrate or gluconeogenics such as propionic acid may alleviate this ketosis and help early development. The digestive system of the chick is physically complete at hatching but is not fully competent at nutrient retrieval as many enterocytes are orientated to immunoglobulin uptake. Villi length and enzymatic activity increases with feeding, reaching maturity within a few weeks. Access to food and water after hatching varies, and long delays until placement are common. These delays cause losses in live performance. Loss in body weight due to late placement or undernutrition may also affect early muscle development. These adverse effects extend to marketing age and reduced meat yield. Factors that affect early chick development are gaining interest as the length of time to market progressively decreases and the chick's first days represent an increasing proportion of the total time for production.

Points that raise animal welfare concerns in the turkey broiler production chain are reviewed. Genetic selection of fast growing strains has increased locomotory problems and made natural mating impossible. A range of different photoperiods are used in practice (constant daylength, increased daylength with age, intermittent lighting) and have many consequences for welfare. High stocking densities have several drawbacks such as poor air quality, cannibalism and impairment of the gait of the birds. Methods of control against cannibalism, which include keeping birds at low light intensities or beak trimming, also raise welfare questions. Studies on the determination of optimal group size and on the possibility of enriching the pen environment are required. Depopulation procedures, transport and slaughter are further causes of poor animal welfare and would also benefit from further research.

Sunflower meal (SFM) has the potential to be a major feed ingredient for poultry in many countries not suitable for extensive soyabean cultivation. SFM is a good source of protein with amino acid availabilities similar to those of soyabean meal (SBM), and much higher than those in cottonseed or rapeseed meals. Its lysine content is relatively low but this can be resolved with supplemental lysine. Fibre content should be decreased to a minimum by dehulling during processing of the sunflower seed for oil extraction. Fibre < 12%) can still cause bulky feed at higher inclusion rates (< 30%), and as a result dietary nutrient dilution (particularly in broiler diets) may occur. Nevertheless, pelleting the diet can help overcome the bulkiness and thereby lead to improved growth and feed efficiency. Another characteristic of SFM is that it does not have anti-nutritional factors such as those found in soyabean, cottonseed and rapeseed meals. Enzyme supplementation to SFM-based diets in different types of poultry species need further study. The ingredient can successfully be included in layer, broiler and waterfowl diets to replace 50–100% of soyabean meal, depending on the type of diet and the nature of the other ingredients.

Mycoplasma synoviae belongs to the class Mollicutes which includes the mycoplasmas, the ureaplasmas, the acholeplasmas and the spiroplasmas. These organisms, most of which are parasites or commensals of plants, insects and animals, are among the smallest prokaryotes capable of independent life. Numerous factors have been associated with the pathogenicity of Mycoplasma infection, including cytadhesion to host target cells, evasion of host immune defences, stimulation of host immune-related self injury, toxin production and harmful effects on host cell metabolism. In animals, mycoplasmas usually colonise mucosal epithelial surfaces of the upper respiratory and urogenital tracts and the mammary gland; however, some mycoplasmas have the potential to invade systemically. Strains of M. synoviae differ in the severity with which they cause disease in poultry, from subclinical infection to upper respiratory disease and, occasionally, septicaemia and synovitis. Current findings indicate that the pathogenicity of M. synoviae in poultry involves attachment and colonisation of the organisms in target tissues; however, one or more as yet unidentified factors seem also to be necessary.

The high incidence of disease is one of the major constraints to smallholder poultry production systems in Africa. In order to control various poultry diseases, ethnoveterinary medicine is widely practised by poor village farmers. Natural products, especially those which are locally available, are generally used. The use of ethnoveterinary medicine can be considered sustainable as it is economical, culturally acceptable and ecologically sound. Although village poultry farmers claim that these practices are effective, there is an urgent need for applied research to substantiate their assertions.

A total of 2083 Culicoides spp. were collected in an ultraviolet light trap hung from the rafters of a laying chicken house at a location in Sebele, giving a mean daily catch of 208.3 biting midges. C. imicola was the most abundant and constituted 57.5% of the total catch. C. leucosticus and C. engubandei constituted 20.5% and 14.770, respectively, of the catch. A comprehensive questionnaire conducted at three sites in the village indicated that many chickens in the homesteads in this location had died as a result of fowl pox. A high incidence of Haemoproteus columbae gametocytes was also found in the cytoplasm of erythrocytes of domestic pigeons (Colurnbiae livia domestica).