Behavioral sampling techniques for feedlot cattle

Continuous observations are an accurate method for behavioral measurements but are difficult to conduct on large numbers of animals because of extensi ve labor requirements. Thus, we sought to develop methods of behavioral dat a collection in feedlot cattle production systems that reasonably approxima ted continuous sampling. Standing, lying, feeding, drinking, and walking be haviors were examined from 224 h of continuous video from 64 heifers. Exper iment 1 (n = 24 heifers) compared continuous behavioral sampling techniques (Continuous) with scan sampling using intervals of 1, 5, 10, 15, 30, and 6 0 min and time sampling (a technique for the periodic recording of behavior ) for the first 10 min out of every 60 min. Means for each scan sampling me thod did not differ in estimated percentage of duration of behaviors (P > 0 .05) from continuous sampling, except for scan sampling with a 60-min inter val. Scan sampling with a 60-min interval differed from more frequent scan sampling intervals for all behaviors except lying. Scan sampling with short intervals (1 and 5 min) was correlated highly with Continuous for all beha viors. The longer the scan interval, the lower the correlations, especially for behaviors with short duration. Time sampling was not an accurate techn ique for measuring the sampled behaviors. Focal animal sampling (using cont inuous sampling of individuals) indicated that one heifer was representativ e of the entire pen of 10 animals (Continuous) for all maintenance behavior s except drinking. Scan sampling methods (1-, 5-, 10-, and 15-min intervals ) were accurate methods of behavioral sampling for feedlot cattle, but scan intervals of 30 or 60 min were less accurate and less precise. Time sampli ng was not an accurate method because it overestimated standing and underes timated lying behaviors. Experiment 2 (n = 40 heifers) investigated the num ber of focal animals required to accurately represent continuous behavioral sampling for all animals. Focal animal sampling was accurate for most beha viors using as few as 1 animal out of 10 but was not an accurate method for drinking behavior unless 40% of the animals in the pen were observed. Esti mates of sample sizes needed for experimental protocols are provided. Behav ioral means, standard deviations, and coefficients of variation are present ed along with estimates of required sample sizes. These results validate ac curate, precise, and efficient methods for quantifying feedlot cattle behav ior.