Flight speed as an indicator of Zebu cattle growth performance and suitability to the feedlot environment

Abstract

Context: Studies assessing the relationship between cattle reactivity and growth performance, as well as suitability to the feedlot, in Zebu cattle are limited. Based on previous studies using Bos Taurus cattle, it is expected that reactivity measured at weaning could be used as a predictor of feedlot performance, and that cattle with greater flight speed (FS) would have reduced average daily gain (ADG). Aims: The aims of this study were to (1) determine if FS (m/s) measured before entry into the feedlot could be used as a predictor of cattle performance, (2) evaluate the consistency of FS over time, and (3) determine when FS should be measured to best predict animal suitability to the feedlot. Methods: A total of 54 Nellore and 40 Guzerat calves were assessed by using FS, which was collected at the time of (FS0) and 1 week after weaning (FS1), as well as on Day 28 (FS28), 56 (FS56) and 168 (FS168) after entry into the feedlot, and a FS average was calculated using FS28, FS56 and FS168 (FS28-168). Performance using ADG (kg/calf.day) was calculated for each animal over three periods: ADG1-28, ADG28-168 and ADG1-168. Bunk attendance (min/calf.day) was recorded over a 173-day feeding period. Key results: The ADG28-168 was reduced by 0.14 kg/calf.day for each unit increase in FS0 (P < 0.05). Both ADG28-168 and ADG1-168 were reduced by 0.02 kg/calf.day for each unit increase in FS1 (P ≤ 0.01), but neither FS0 nor FS1 was associated with ADG1-28 (P > 0.10). A significant increase was observed between FS1 and FS28 (P < 0.01), followed by a reduction in FS56 (P < 0.01) and FS168 (P < 0.01). Conclusion: FS measured at or within 1 week of weaning has the potential to be used as an indicator of feedlot growth performance in Nellore and Guzerat cattle. Implications: Although our results do not indicate the efficacy of FS as a predictor of early suitability of cattle to the feedlot, it does have the potential to support its recommendation as an indicator of overall feedlot growth performance in Nellore and Guzerat breeds.