RESEARCH ▶▶▶


Four slow-growing broiler genotypes get approval


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BY HELEN LOUTON, CHRISTIANE KEPPLER, MICHAEL ERHARD, OTTO VAN TUIJL, JOSEF BACHMEIER, KLAUS DAMME, SVEN REESE AND ELKE RAUCH.


n Germany and many other countries there are various la- belling programmes for the rearing of broiler chickens to meet higher welfare standards. In addition to reduced stocking densities, alternative genotypes have also been


suggested for use in welfare labels and have been studied for productivity or meat quality that complies with animal welfare and health indicators. In this article ‘slow-growing’ is defined as a growth rate of no more than 49.2 to 50.7 grammes/day. In consultation with scientific, agricultural, trading and pro- cessing stakeholders the German Animal Welfare Association established an animal welfare label for broilers. The pro- gramme provides for a two-stage label with an entry level and a premium level. The entry level requires an improve- ment in animal welfare compared to government require- ments, for example, through reduced stocking densities, pro- vision of environmental enrichment and a winter garden or the use of alternative genotypes. For the premium stage the broilers must have access to an outdoor run; a standard housing requirement in organic farming. For a new genotype to be approved an application must be submitted to the organisation. The breeder or applicant has to provide data confirming that the average daily gain in 56 fattening days does not exceed 45 g/day. The Association then decides whether to grant approval and might ask for more data on weight development and the welfare of the genotype, including an assessment of animal welfare indica- tors. Competent authorities in the European Union common- ly apply animal-based welfare indicators such as foot pad dermatitis, dead on arrival, total rejections, ascites, cumula- tive daily mortality, joint lesions, hock burn, breast lesions, emaciation, wing fractures, cellulites, respiratory disease and scratches. Not all animal welfare associations use the same list of indicators and treshholds. Sometimes gait score as- sessed on the farm, as well as foot pad dermatitis and hock burn assessed at slaughter, are added. The aim of this study was to examine and compare the preva- lence of animal-based welfare indicators in four slow-grow- ing broiler genotypes. Correlations between these indicators and access to a mandatory winter garden were examined. The body weight of the four broiler genotypes differed on


Broilers of four slow-growing broiler genotypes (Ranger Classic, Ranger Gold, Rowan Ranger and Rambler Ranger) were tested for potential approval of these genotypes for a German animal welfare label programme. Animal-based welfare indicators were assessed after 36 and 44 fattening days.


both examination days (36 and 44 days). Walking ability was within the scope of the animal welfare label for all genotypes. It was better in genotypes with a lower mean body weight and correlated positively with body weight in three geno- types. Hock burn was only observed at a low severity score, with male broilers affected more often than female broilers. A positive correlation in the development of hock burn with the weight of the broilers was observed after 44 fattening days when data for all the genotypes were pooled. The footpads of all the broilers examined were without lesions at both exami- nations. Skin scratches were observed in all genotypes at both examinations, with Ranger Classic showing a higher prevalence of more severe scratches. Broilers in pens with ac- cess to a winter garden were more often affected by skin scratches than broilers without. With the exception of weight gain in two genotypes, the indicators assessed showed that all genotypes met the requirements of the animal welfare la- bel. The assessed indicators were suitable for use in an animal welfare label programme, although the mandatory winter garden resulted in more skin scratches.


In consultation with scientific, agricultural, trading and pro- cessing stake- holders, the Ger- man Animal Welfare Associa- tion established an animal wel- fare label for broilers.


▶ POULTRY WORLD | No. 9, 2019


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PHOTO: SEBASTIAAN ROZENDAAL


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