|Cheng, Heng Wei|
Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/10/2007
Publication Date: 3/1/2008
Citation: Marchant Forde, R., Fahey, A.G and, Cheng, H. 2008. Infrared Beak Treatment: Part I, Comparative Effects of Infrared and 1/3 Hot-blade Trimming on Beak Topography, Focal Behavior and Growth.. Poultry Science. 87:1474-1483. Interpretive Summary: Beak trimming poultry functions to reduce and/or inhibit undesirable behaviors such as inter-bird pecking, aggression and cannibalism. As with most invasive husbandry procedures, beak trimming has solicited a great deal of debate and research concerning the relative advantages and disadvantages of the practice from an animal well-being perspective. Infrared beak trimming is a completely automated process where day old chicks are immobilized using a head restraint and infra-red energy is focused on the area of the beak requiring trimming. The present work is the first in a series of studies designed to evaluate the effectiveness and effects of infrared beak trimming on layer well-being. The specific objective of this work was to compare the temporal effects of infrared and hot-blade trimming at 1 day of age on subsequent behavior and growth of layer chicks from 0 to 10 weeks of age. On the whole, it appears that both trimming methods had similar impacts on production and well-being parameters. Based on earlier studies we would have predicted that infrared treated birds would perform more poorly given that the amount of beak removed in these birds was more severe. Further work is necessary to examine the effects of removing equal amounts of beak tissue using infrared and hot-blade methods so we can fully evaluate the relative impact of these procedures on production and wellbeing. These findings could be adapted by producers and other scientists for future development of animal wellbeing standards and guidelines for management practices.
Technical Abstract: This study examines the effects of beak trimming on production and well-being. Seventy-two layer chicks were assigned to hot-blade trimming (HB), infrared treatment (IR), or a control(C) untrimmed treatment at one-day-old. Chicks were pair housed by treatment and beak images, behavior and production indices were obtained post-treatment and at fixed intervals for 9 weeks. All beaks were normally shaped at the onset of the study and no perceptible treatment related differences in shape occurred over time (P>0.05). Different trimming methods did, however, result in: varying proportions of trimming across treatment (P<0.01); different beak regrowth rates (P<0.01) and; deviations from normal upper-to-lower mandible length ratios (P<0.01). Immediately post-treatment, HB birds had shorter beaks relative to the other two groups (P<0.05). C and IR beaks remained comparable in length until the onset of tissue degeneration and erosion of the IR beaks 1 to 2 weeks post-treatment. Thereafter, there was an increase in beak length in all treatments over time (P<0.01). Two weeks post-treatment, beaks were longest in C, intermediate in HB (P<0.001) and shortest in IR birds (P<0.001). Finally, HB birds exhibited more deviations from what would be considered a normal upper-to-lower mandible length ratio than the other treatment groups (P<0.05). For most behavior indices, any treatment related differences dissipated within 1 week after trimming. Inactivity was higher in trimmed birds for up to 4 d post-treatment (P<0.05), was highest in the HB birds for 24 h post treatment (P<0.05) and tended to be higher in the IR birds during d 3 and 4 afterwards (P<0.01). Notable effects of treatment on production emerged by +2 d and persisted for up to 5 weeks. Growth and feed intake were suppressed in HB and IR compared to C birds (P<0.05). Feed intake did not differ between treatments aside from a reduction in intake in the IR treatment during week 3 (P<0.05). Feed waste was lowest in the IR group but alternated in magnitude between the other two groups (P<0.05). Growth was suppressed for 3 weeks in the HB birds and for 4 weeks in the IR group (P<0.05). Thereafter IR birds performed numerically, though not statistically, better than the HB group indicating a certain degree of compensatory gain. Results indicate that early production parameters are impacted by both trimming methods. While the impact of trimming appears greatest in the IR birds initially, these differences dissipated quickly and overall performance is similar in both groups. More severe trimming is nearly always associated with persistently poorer outcomes than those caused by more moderate trimming. IR birds in this work were more severely trimmed than HB birds so we would have predicated a more sustained negative response in the IR birds. Further work is pending that examines the effects of standardized IR and HB trimming (½ beak) on production and welfare.