Förbättring av djurskydd och välfärd vid lastning av slaktkyckling

Transport of animals is of a big concern and different means to improve welfare and decrease transport mortality or dead on arrival, DOA, must be looked for. In a previous/former project,”Chicktrans”,it was concluded that the incidence of DOA of broiler chickens, was not affected by transportation time or by the outer climate during transport to the processing plant. Although, it was found that DOA between farms, delivering to the same processing plant, differed significantly. The aim of this study was to examine differences in the condition/health status of the broiler chickens, influenced by climate management of the chicken house, during their last week and the day for catch. The litter quality was also a factor examined for influencing broiler chickens and contributes to chickens being “fit for transport”. One of many animal welfare and health status measures, affected by stable climate management, is foot score, which we also have chosen to study. The aim of the study was therefore to analyze if there are differences among measurable variables, which could explain why some breeders always managed to end up with low and some with a high incidence of DOA, when delivering to the processing plant, during the period from year 2001 to 2008. The study was collaboration with a processing plant of Kronfågel in Kristianstad, Sweden. We selected breeders who consequently had produced broiler chickens with low incidence of DOA, A-farms, and those who had produced at a higher incidence of DOA, B-farms. Nine A-farms and six B-farms from region Skåne and Blekinge, were involved in this study. During the period from year 2001 and 2008, the incidence of DOA was in average 0,085% +/- 0,038 at the A-farms, which was significantly lower (p<0,0001) compared to 0,187% +/- 0,060 at the B-farms. The breeders also answered a survey to get basic data from the farms. Kronfågel contributed with slaughter data from the selected farms. The investigation was divided in two periods for each farm, the last week before catch and the day of catch. Measurements were performed during midst of the summer until late autumn, during year 2008. A total of 473 776 broiler chickens (Ross 308) were slaughtered. Loading staff, feed supplier and straw material were the same at all A- and B-farms. Transportation time never exceeded 3 hours. During the last week before catch, temperature and relative humidity was measured with loggers at two different points on the litter, 15 cm above surface and one logger was placed outdoors. At the day of catch, CO2-levels were also measured at floor level, at the front where the birds were picked up by the machine. Nine of the farms had their catching during daytime, while six of the farms had their catching during nighttimes. In connection with loading, samples were taken at 9 different points to evaluate the moisture content in the litter. More than half of the farms were build in the beginning of the year of 2000, large buldings at a total of around 4 000 m2, divided into two sections. The smallest farms were built in the beginning of the year of 1970/the seventies, with an area of around 660 to 2 112 m2 per section. The ventilation was in overall exhaust (under pressure) ventilation systems from different manufacturers. Table A summarize the results from our research. Both the level and the difference between A- and B-farms regarding DOA, were the same during our project as during the period of year 2001-2008. The analyzes showed no correlations between DOA and the parameters measured which could give any expla-nation regarding climate in the broiler house, and why the A-farms had a lower incidence of DOA. Despite a low foot score at the A-farms compared to B-farms, there was higher moisture content in the litter at A-farms, although no signinficant differences. Table A. Summary of the results from our research and data from the processing plant A-farms B-farms P-value Floor area, m2 1 662 1388 0,36 Stocking density, kg/m2 34,1 36,6 0,26 Slaughter weight, kg 1,68 1,76 <0,05 Moisture content in litter, % 40 36 0,20 Loading time, hour 5,2 4,3 0,47 House temp, measure period,°C 25,7 24,2 0,11 Relative humidity, measure period, % 72 68 0,09 House temp, loading, °C 24 22 0,19 Relative humidity, loading, % 79 74 0,05 THI, loading 73 69 <0,05 Control of ventilation (5 = top score) 2,9 3,5 0,31 CO2 loading, ppm 709 730 0,51 DOA, % 0,08 0,18 <0,001 DOA, 2001 – 2008, % 0,085 0,197 <0,00001 Foot score 30 59 0,36 (low value is best) The loading staff together with the breeder or farm hands did a good job to maintain the underpressure ventilation during catching and opening of door for the truck. No signs of “puncturing” of the ventilation were seen. The theoretical air flow rates in the houses was generally only 50% of the recommended and the controls of the venti-lation (fans) was in many cases not working satisfactory. This should be controlled and improved. For future research it is suggested that systematically investigation of how to establish and maintain the litter in good shape i.e. moisture content should not exceed 37 % to increase the presumption to reach a low foot score.