Welfare of broilers on farm.

This Scientific Opinion considers the welfare of domestic fowl (Gallus gallus) related to the production of meat (broilers) and includes the keeping of day-old chicks, broiler breeders, and broiler chickens. Currently used husbandry systems in the EU are described. Overall, 19 highly relevant welfare consequences (WCs) were identified based on severity, duration and frequency of occurrence: 'bone lesions', 'cold stress', 'gastro-enteric disorders', 'group stress', 'handling stress', 'heat stress', 'isolation stress', 'inability to perform comfort behaviour', 'inability to perform exploratory or foraging behaviour', 'inability to avoid unwanted sexual behaviour', 'locomotory disorders', 'prolonged hunger', 'prolonged thirst', 'predation stress', 'restriction of movement', 'resting problems', 'sensory under- and overstimulation', 'soft tissue and integument damage' and 'umbilical disorders'. These WCs and their animal-based measures (ABMs) that can identify them are described in detail. A variety of hazards related to the different husbandry systems were identified as well as ABMs for assessing the different WCs. Measures to prevent or correct the hazards and/or mitigate each of the WCs are listed. Recommendations are provided on quantitative or qualitative criteria to answer specific questions on the welfare of broilers and related to genetic selection, temperature, feed and water restriction, use of cages, light, air quality and mutilations in breeders such as beak trimming, de-toeing and comb dubbing. In addition, minimal requirements (e.g. stocking density, group size, nests, provision of litter, perches and platforms, drinkers and feeders, of covered veranda and outdoor range) for an enclosure for keeping broiler chickens (fast-growing, slower-growing and broiler breeders) are recommended. Finally, 'total mortality', 'wounds', 'carcass condemnation' and 'footpad dermatitis' are proposed as indicators for monitoring at slaughter the welfare of broilers on-farm.

Culture-independent identification and quantification of Gallibacterium anatis (G. anatis) by real-time quantitative PCR.

Gallibacterium is a genus within the family Pasteurellaceae characterized by a high level of phenotypic and genetic diversity. No diagnostic method has yet been described, which allows species-specific identification of Gallibacterium anatis. The aim of this study was to develop a real-time quantitative PCR (qPCR) method allowing species-specific identification and quantification of G. anatis. A G. anatis specific DNA sequence was identified in the gyrase subunit B gene (gyrB) and used to design a TaqMan probe and corresponding primers. The specificity of the assay was tested on 52 bacterial strains. Twenty-two of the strains represented all of the presently available 13 phenotypic variants of G. anatis originating from different geographical locations. Nine strains represented each of the additional six Gallibacterium species and 21 strains represented other poultry associated bacterial species of the families Pasteurellaceae, Enterobacteriaceae and Flavobacteriaceae. Regarding specificity none of non-G. anatis strains tested positive with the proposed assay. To test and compare the qPCR method's ability to detect G. anatis from field samples, the sensitivity was compared to a previously published conventional PCR method and culture-based identification, respectively. The detection rates were 97%, 78% and 34% for the current qPCR, the conventional PCR and the culture-based identification method, respectively. The qPCR assay was able to detect the gene gyrB in serial dilutions of 10(8) colony forming units (CFU)/ml to as low as 10(0) CFU/ml copies. The proposed qPCR method is thus highly specific, sensitive and reproducible. In conclusion, we have developed a qPCR method that allows species-specific identification of G. anatis.