Can a Modified Latency-to-Lie Test be Used to Validate Gait-Scoring Results in Commercial Broiler Flocks?

Abstract

AbstractBodily contact with water is a novel and aversive experience for broiler chickens, and this has been used when designing the Latency to Lie (LTL) test. The original testing procedure, in which the birds are tested in groups, involves a certain settling period, which makes the test time-consuming to carry out on commercial broiler farms. Our modifications of the LTL test for on-farm use mean that a) the birds are tested individually without visual contact with other birds; and b) the water tub is already filled with water when the birds are placed in it. The results from the LTL tests can then be compared with the scores achieved for each individual bird on the commonly used ‘gait scoring’ procedure. At 14 farms participating in a larger survey, we used three birds of each gait score from 0 to 4 (when available) for LTL testing. The time spent standing before making the first attempt to lie down was recorded. The results show a clear negative correlation (r = -0.86, P < 0.001) between time spent standing and gait score. The mean LTL values for the different gait scores were all significantly (P < 0.01) different. There was no significant difference in LTL results between flocks. The method described appears to be well suited for on-farm use. If further developed, it could become a useful tool in monitoring programmes for the ongoing efforts aiming at decreasing the levels of leg weakness in modern broiler production.