Effects of different infrared beak treatment protocols on chicken welfare and physiology

Infrared beak trimming provides an alternative to conventional trimming, purporting to provide a welfare-friendly means of trimming. The infrared system can be adjusted to use multiple plate and power settings. In the present study, we used 2 different plate sizes (27/23C, less severe; 25/23C, more severe) with each of 3 power settings: high (52), moderate (48), and low (44). These birds, along with conventionally (hot blade; HB) trimmed birds were maintained in an industry egg-laying facility. Physiological and behavioral measures were taken at 5, 10, 20, and 30 wk. All birds followed a similar growth curve; birds from the 27/23C (48) protocol were the heaviest across all ages and 25/23C (44) birds were the lightest. Upper and lower beak growth curves showed birds trimmed with 25/23C protocols had shorter upper and lower beaks compared with 27/23C protocols or HB. Birds trimmed using 27/23 (44) and (48) had consistently longer upper and lower mandibles. Amount of feed wasted was greatest in HB and 27/23C birds and tended to be reduced in 27/23 (48) and 25/23 (48) and (52) birds (P < 0.10). Beak-related behaviors (eating, drinking, and pecking) were measured to observe the effects of trimming protocol on beak usage, which could indicate beak pain or morphological changes that inhibit normal behaviors. Walking behavior was also measured to assess overall activity. Behavior analysis revealed that compared with HB-trimmed birds, those of 27/23C protocols walked and drank more at a young age. At 5 and 10 wk of age, a test feather was attached to the cage and pecking at as well as the damage score of the feather were determined. Birds from 27/23C (44) and (48) protocols pecked significantly more at the feather than HB, whereas HB and 25/23C (52) birds had the highest damage score. The results from the study suggest that infrared protocols can be optimized for superior productivity as well as animal well-being.