The effects of organic diets, with or without supplements of betaine, saponin, fructo-oligosaccharide and methionine, on the health, performance and gut flora of pullets were investigated. A comparison was also made between birds fed organic diets and those fed a non-organic diet. Day-old Lohmann Tradition pullets were reared in 24 groups of 64 chicks indoors until 11 weeks, and then in 48 groups of 24 to 27 chicks with access to range until 17 weeks of age. Groups of birds were fed one of eight diets, a conventional rearing diet with supplementary amino acids, an organic basal diet, organic basal plus methionine and organic basal supplemented with one of the test ingredients. At most stages of growth the birds fed the conventional diet and those fed the basal diet with methionine performed better than those that had no supplemental methionine. Other dietary treatments had no consistently significant effect on growth, the microbial populations within the gastro-intestinal tract of the birds or the number of parasite eggs excreted. After 5 weeks with access to range, the birds that were fed three out of five diets regarded as deficient in sulphur amino acids achieved similar weights (P > 0.05) to birds that received diets adequate in sulphur amino acids. Health and welfare of birds fed organic diets was not adversely affected; however, an investigation of birds housed in larger flocks and taken into the laying phase, when physical demands on birds are greatest, is required.

In the near future EU-legislation will ban the use of conventional battery cages, while national legislation in some countries in Western Europe will ban beak trimming as well. The ban on battery cages and beak trimming causes an increased risk of feather pecking and cannibalism in laying hens. Many factors influence feather pecking behaviour, but this paper focuses on nutritional factors. Nutritional factors can have positive and negative effects on feather pecking behaviour in laying hens. Severe feather pecking has been demonstrated in birds that were fed a too low mineral level in the diet, a too low protein level or a too low amino acid level (methionine, arginine). Sometimes somewhat more feather pecking was found when layers were fed diets with mainly vegetable protein sources as compared with diets with protein from animal origin. Also more feather pecking may occur when the diets were fed restrictedly, fed coarsely ground, or fed as pellets. Feeding high-fibre diets, low energy diets, or roughages reduced feather pecking. Providing additional grain or straw in the litter during rearing could result in lower levels of feather pecking behaviour in adult stages. Some of these positive effects on feather pecking seem to be related to the time birds spend on feed intake and foraging. This paper gives an overview of the relationships between the occurrence of feather pecking behaviour and nutritional factors, such as diet composition and feeding strategies in laying hens.

Evidence from published trials is reviewed to investigate whether there is any need to change the recommended optimal light intensity for laying fowls from 5 lux. Although some recent trials have recorded excellent performances from birds exposed to light intensities of less than 5 lux, it is concluded that this has more to do with the ability of modern pullets to lay well even without photostimulation than with any change in the threshold of light sensitivity. There is good recent evidence that the stimulation of early sexual maturity a large increment in the photoperiod during the growing stage requires minimal intensity of 2lux, and that 41ux is probably required for maximal response. By combining the results from all available trials, it is possible demonstrate small but significant effects of light intensity on egg size, food intake and mortality. An economic analysis, which takes into account all these responses, indicates that the optimal profit occurs at about .5 lux. Although the prices used in that analysis are both local and ephemeral, the optimum will vary very little within other cost structures, because it is determined almost entirely by the lower outputs predicted at intensities below 51ux and the greater electricity cost in providing very much higher intensities. It recognised that, because maximising profit is not always the sole objective enterprises involving animal production, considerations for the welfare of both the livestock and workers may make it prudent to recommend a slightly higher value such as 1O lux.

An analysis of data for domestic pullets, turkeys, partridges and quail (Coturnix) indicates that, once all birds within a flock have become sexually photoresponsive but before spontaneous sexual development commences, mean age at first egg, egg production in a given period, mean body weight at first egg and mean egg weight increase linearly with age at photostimulation. These relationships are steeper for age at first egg in turkeys, partridges and quail, for egg production in turkeys and partridges and for egg weight and body weight in turkeys than those seen in domestic pullets. This may indicate differential responses by seasonal and non-seasonal breeding birds, species-specific factors such as geographical origins, or may reflect differing periods of artificial selection in the four species. Egg weight in domestic pullets and turkeys is significantly correlated with body weight at first egg.