RT Dissertation/Thesis T1 Dose Titration, Tolerance and Compatibility of some Feed Additives in Broiler A1 Islam,Khan Shaiful WP 2005/08/17 AB In two dose titration studies on chicken for fattening growth promoting efficacy and some aspects of safety of fumaric acid (FA), an approved preservative, and humic acid (HA), approved as veterinary drug, were examined. In a third experiment on chicken for fattening the compatibility of the ionophore coccidiostat semduramicin (AVIAX®), also approved at EU level, with the veterinary antibiotic tiamulin should be investigated. In experiment 1 six diets with increasing FA contents were fed for 26 days to 96 newly hatched male chicks per treatment. Final body weight (feed efficiency) amounted to 1,506 (756), 1,597 (767), 1,532 (754), 1,485 (759), 1,342 (738), and 1,378 g (747 g gain kg-1 feed) for the groups with 0, 1.25, 2.50, 3.75, 5.0, and 7.5 % FA, respectively. The 1.25 % FA group showed significantly (p<0.05) better weight gain than all other groups and better feed efficiency than the groups with 5.0 and 7.5 % FA. Body weight of the 5.0 and 7.5 % FA groups was significantly lower than that of the other groups. The relative organ weight was not affected by the treatment. In experiment 2 six diets containing 0, 0.3, 0.6, 1.2, 2.4, and 4.8 g Huminfeed® (74 % humic acid in DM) kg-1, respectively, were fed for 35 days to 80 newly hatched male chicks per treatment. Initially HA depressed weight gain, but recovery started in the third week, so that at the end no significant differences could be observed. But body weight gain was negatively correlated with the HA content of the diets (y (weight gain) = 2327.98 ? 0.0181x (Huminfeed content), r = -.280*). Feed intake was not affected by the treatment. The relative organ weights did not differ among the groups. Experiment 3 (35 days) with a total of 320 female broilers chicks was conducted to study the effect of 25 mg semduramicin kg-1 feed and the potential interference between semduramicin and tiamulin on zootechnical parameters (10 replicates with 8 chicks each), haematology, blood routine biochemistry and health status (1 chick per replicate). Tiamulin medication (250 mg L-1 water) from day 15 to 19 reduced significantly water intake, especially when concurrently given to birds fed semduramicin. Also feed intake was depressed in that period. Body weight gain of the semduramicin/tiamulin group in the third week was affected too. After 35 days, body weight (feed efficiency) was 2,062 (665), 2,067 (669), 2,084 (678), and 2,008 g (679 g gain kg-1 feed) for the control, the tiamulin, the semduramicin and the semduramicin/tiamulin group, respectively. All data obtained form haematology, blood biochemnistry ad pathology did not give evidence for any adverse influence of the coadministration of tiamulin and semduramicin. After a withdrawal period 20 broilers from the control and the semduramicin group were slaughtered and examined for product quality. No treatment effects (P>0.05) on hot carcass weight, viscera, dressing percentage, edible portions (breast muscles, haunch), fat and skin portions were seen. Also the sensory characteristics (juiciness, tenderness, unpleasant pungent aroma, general impression) except the aroma/flavour were not influenced by the treatment. K1 Kompatibilität K1 Broiler K1 Fumarsäure K1 Huminsäuren K1 Antibiotikum PP Hohenheim PB Kommunikations-, Informations- und Medienzentrum der Universität Hohenheim UL http://opus.uni-hohenheim.de/volltexte/2005/105