Effect of group size on processing time and some stress-related behaviors in cattle in straight chutes

Abstract

Stress during handling can affect welfare in beef cattle and pose a risk to handlers. An evaluation was done of processing time and stress-related behavior (vocalization, turning, jumping, hitting, falling) in cattle during transit through a straight chute. Eight herds of 50 Brahman x Swiss Brown animals each were processed over an 8-d period. Each herd contained the same proportions of young to adult animals, and female to male ratios. Four herds were processed in small groups of four to five animals (TS), and the remaining four in groups of ten to twelve animals (TG). Processing involved moving the animals through a 13-m long straight chute during which they were injected with 1% Ivermectin. Processing time was shorter (P<0.05) in the TS (42.5 ± 2.2 min) than in the TG (51.04 ± 1.9 min). Vocalization (5.5 ± 0.6 vs 7.7±0.2), turning (6.3 ± 0.4 vs. 9.5 ± 0.6), and jumping (2.7 ± 0.5 vs. 5.2 ± 0.5) occurred less frequently (P<0.05) in the TS than in the TG. No differences between treatments (P>0.05) were observed for hitting (TS: 2.7 ± 0.4; TG: 5.5 ± 1.7) or falling (TS: 2 ± 0.4; TG: 3.7 ± 1.0). Processing small groups resulted in shorter processing times, less stress to animals and lower risk of injury to animals and handlers. This practice is a viable option for improving processing efficiency and animal welfare in semi-intensive tropical beef cattle systems.