Performance, foot-pad dermatitis and haemoglobin saturation in broiler chickens kept on different types of litter Leistung, Häufigkeit an Pododermatitis und Hämoglobinsättigung bei Broilern bei Haltung auf verschiedenen Einstreusubstraten

Intensive selection of broiler breeders in the direction of rapid growth rate and increased final body weight has led to the appearance of a number of metabolic diseases in broilers. The most important among them include sudden death syndrome (SDS) and ascites which are directly associated with cardiovascular and respiratory system failure of rapidly growing birds (KRANEN et al., 1998; IMAEDA, 2000; WIDEMAN, 2001). Ascites is connected very frequently with the phenomenon of hypoxemia caused by reduced oxygen content in blood (BUYS et al., 1999). Both, lower blood oxygen pressure (pO2) and smaller haemoglobin saturation (PEACOCK, 1990; OLKOWSKI et al., 1999) were observed in fast-growing broiler chickens. Thus, it must be underlined that cardiovascular and respiratory system efficiency cooperation, whose dysfunction influences significantly the incidence of ascites, can depend not only on bird’s rate of growth but also on environmental conditions in which they live, including litter quality. It was shown, that dust in the airspace of broiler chickens may increase the incidence of ascites. It can effectively reduce the efficiency of oxygen uptake inside the lungs (ZUIDHOF et al., 1997). There were also experiments which tried to analyze the frequency of ascites occurring in broilers when litter with canola oil was used to decrease its dust (MCGOVERN et al., 1999). It was also affirmed that the level of ammonia in the air affects ascites incidence (TERZICH et al., 1998). Among increasing problems in broiler chicken and turkey rearing there are contact skin inflammations which can occur either in the form of oedema in the area of breast, popliteal fossa or, most frequently, in the region of foot-pad (foot-pad dermatitis – FPD) (EKSTRAND et al., 1998; KJAER et al., 2006). Serious lesions of the pad can be very painful and cause stress and lead to the appearance of other infections causing deterioration of general health condition and reduced production results, including poorer body weight gains and lower final body weights (MARTLAND, 1984 and 1985; CAMPO et al., 2005). Among major factors, the type and quality of litter seems to contribute to the above-mentioned problems. Already MARTLAND (1984) and GREENE et al. (1985) reported interrelationships between litter moisture content and frequency as well as prevalence of foot-pad dermatitis in broiler chickens. In addition, also HESTER et al. (1997) found that the use of course particleboard residue as litter for turkey led to the increase of FPD incidence in comparison with birds which were kept on fine particleboard residue or wood shavings. Therefore, it seems that the relation between the type of litter and the FPD prevalence results in all probably from water content in examined litter. Thus, a higher water content in the litter impairs the wellbeing of the legs. In view of the above, it seems important to carry out investigations involving, among others, the analysis of the suitability of rearing broiler chickens on different types of litter, the possibilities of improvement of its quality and the impact of the applied substrate on health and performance of broilers (GOETSCH et al., 1998; IVANOV, 2001; SOGUNLE et al., 2006) taking into consideration primarily their welfare. Bearing in mind a number of activities already in progress aiming at the improvement of effectiveness and profitability of broiler chickens rearing, the authors of this study adopted as the objective of their investigations the determination of the impact of different types of litter employed in broiler chicken rearing on their performance and health condition. In addition, they aimed to find the answer to the question which of the applied litters is the best.