Dietary Resin Acid Concentrate Improved Performance of Broiler Chickens and Litter Quality in Three Experiments.

Dietary coniferous resin acids have previously been suggested to support the intestinal integrity of broiler chickens by reducing mucosal collagen degradation. The present study examined the effects of resin acid concentrate (RAC) on broiler performance and litter quality. In trial 1, RAC was added to diets at 0, 125, 250, or 1250 g/ton, while in trials 2 and 3, RAC dosing was 0 or 175 g/ton. Bird weight, feed consumption, mortality, feed conversion ratio (FCR), European Efficiency Index (EEI), litter moisture, and footpad dermatitis (FPD) lesions were measured. In trial 1, RAC at 125 and 250 g/ton improved weight gain and EEI, while RAC at 1250 g/ton group did not differ from control. Feed consumption, FCR, FPD scores and mortality were similar in all treatments, but litter quality was improved by all doses of RAC. In trials 2 and 3, RAC increased the final weight of birds, improved FCR, EEI, and litter quality, but had no effects in other parameters. In summary, RAC at 125-250 g/ton improved bird performance and thus shows promise as a feed additive. The dryer litter in RAC treatments may suggest improved intestinal condition as a response to in-feed resin acids.