Interrelationships between Two Gait Scoring Systems, Tibia Ash Contents, Body Weights and Latency-To-Lie of Commercial Broiler Chicken

Abstract

Leg abnormalities are among the most serious welfare problems in broiler production. Tibia ash content, latency-to-lie and gait scoring systems are used to evaluate the status of leg health of broilers. Objective of this study was to determine the relationships between body weight, tibia ash, latency-to-lie and two gait scoring systems [6 point and 3 point). A total of 90 broilers [Cobb) were observed individually for gait scores on day 53 and latency-to-lie times by a single observer. Eighty three percent birds had at least detectable level of gait abnormality as of 6 point scale. According to the three point scale, only 14.2% birds were classified either having obvious or severe leg impairments. The percentage of broilers showing "complete lameness” or "severe impairment" was 2.8% . The percentage of birds classified into scale 0 of three point system was higher than the sum of percentages of birds in scale" 0" and scale' 1' of the six point scale. There was no significant correlation between gait scores and the body weight. Tibia ash content reduced linearly with increasing [bad) gait socres of both scoring techniques. Furthermore, no statistically significant relationship was detected between gait scores and the latency-to-lie time. Indicating seriousness of the welfare problem that needs immediate attention, birds having severe leg abnormalities or complete lameness had as low as 7 seconds of latency -to-lie times. It ws concluded that apart from aiding to identify best and worst cases, latency-to-lie time did not prove to be a good indicator to detect leg abnormalities. Six point scoring techniques was proved to be better than three point scoring system to detect leg abnormalities of broilers