Browsing by Subject "opinnäytteet"

The experiment was a part of a project concerning national adaptation of the European Union directive on the protection of chickens kept for meat production. One of the aims of the project was to improve broiler chickens’ welfare by exploiting Welfare Quality® assessment system. The objective of this thesis was to find environment and management factors that could explain the differences in broiler flocks’ cleanliness, foot pad and hock health and walking ability. The hypothesis was that the distinction between the results obtained from animal-based measurements can be explained by the differences in environment and management factors. The experiment conducted in winter 2013 and a total of 22 farms and 45 broiler flocks participated in the experiment. The research sample represents about a 10 percentage of the all the Finnish farms that rear broiler chickens. The broilers were Ross 508 or Ross 308 hybrids. At the time of the visit flocks were expected to be slaughtered within a week. The flocks were assessed by using Welfare Quality® assessment system. Cleanliness of the birds was assessed by using a scale from 0 (clean) to 3 (very dirty). Foot pad and hock lesions were assessed by using a scale from 0 (no lesions) to 4 (severe). The walking ability of the broilers was assessed by using a scale from 0 (smooth) to 5 (unable to walk). Litter quality was good and the mean value was 0.66 when the scale ranged from 0 (dry) to 4 (wet). Air quality was quite good as measured by dustiness. There were only a few panting birds, which indicated that the temperature of the houses was right for the birds. All the flocks were clean, the mean value was 0.97. Older and heavier birds were slightly dirtier. The foot pad and hock health was overall good, because over 70 % of the birds had a score of 0. The mean value for foot pads was 0.40 and for hocks 0.31. The good litter quality correlated with better foot pads and hocks. Heavier birds had a better foot pad score and the hock score was better, when the birds were younger. The walking ability was impaired by the age of the birds and by the low stocking density (birds/m2). A regression analysis was conducted to find the relationships among variables. The analysis could create prediction models for broiler flocks’ cleanliness, foot pad score, hock score and walking ability that only had a weak or a moderate coefficient of determination. All the models had independent variables that were obtained from the data collected at the slaughter house. An interesting finding was that the variable “percentage of the birds discarded because of emaciation” was among all the created prediction models. This experiment suggests that the emaciation percentage of the flock reflects the overall health and the level of management of the flock. There are not many differences in rearing conditions between Finnish broiler houses and therefor it was difficult to find any statistical relationship between the measurements. All the flocks were quite clean and had healthy foot pads and hocks.