Validation of scan sampling techniques for behavioural observations of pastured lambs

Abstract

The study of farm animal behaviour is a critical tool for assessing animal welfare. Collecting behavioural data with continuous sampling or short scan sampling intervals (eg every 60th second) is considered ideal as this provides the most complete and accurate dataset; however, these methods are also time and labour intensive. Longer sampling intervals provide an alternative in order to increase efficiency, but these require validation to ensure accurate estimation of the data. This study aims to validate scan sampling intervals for lambs (Ovis aries) housed on pasture. Grazing, lying, standing, drinking, locomotion, and mineral consumption were evaluated from six pens of crossbred lambs (six lambs per pen) for 15 h. Data from 1-min instantaneous scan sampling were compared with data from instantaneous scan sampling intervals of 5, 10, 15, and 20 min in two statistical tests: generalised linear mixed model and regression analysis. Using the mixed model, the percentage of time each behaviour was performed did not differ amongst sampling intervals for all behaviours except grazing, which was statistically different at 20-min intervals. Using regression analysis, lying and grazing estimations were accurate up to 20-min intervals, and standing was accurate at 10- and 20-min intervals only. Locomotion, mineral consumption, and drinking demonstrated poor associations for all tested intervals. The results from this study suggest that a 10-min instantaneous scan sampling interval will accurately estimate lying, grazing, and standing behaviour for lambs on pasture. This validation will assist with the efficiency of future data collection in lamb behaviour and welfare research.

Diurnal Concentration of Urinary Nitrogen and Rumen Ammonia Are Modified by Timing and Mass of Herbage Allocation

“…One trained observer was assigned to each group to record grazing behavior of each cows. Grazing activity was recorded using an instantaneous scan sampling at intervals of 10 minutes during daylight and 15 minutes during night [11,21]. Cows were considered as grazing when standing or walking with muzzle close to grass (i.e.…”

“…Cows were considered as grazing when standing or walking with muzzle close to grass (i.e. head is below shoulders) [21] and eating activity was maintained for one minute or more. Cows were painted with large numbers on their sides to assist identification and avoid altering normal grazing behavior.…”

Technical note: Instantaneous sampling intervals validated from continuous video observation for behavioral recording of feedlot lambs1

“…Collectively these behaviors encompassed 4.3% of the daily time budget for the feedlot-housed lambs in this study (0.7, 2.0, and 1.6% for drinking, locomotion, and oral manipulation, respectively) and were performed in bouts of ≤10 s. These findings are similar to those of Das et al (1999), who reported that feedlot lambs perform drinking in bouts of 1 min for 0.3% of a 24-h day. Additionally, Pullin et al (2017) found that locomotion and drinking behavior of lambs housed on pasture were not accurately estimated using 5-, 10-, 15-, or 20-min intervals. Results from the present study support methodologies in previous literature, where researchers used continuous sampling to collect data on stereotypies or abnormal behavior in confined lambs (Vasseur et al, 2006;Aguayo-Ulloa et al, 2014;Teixeira et al, 2014).…”

“…Lying behavior plays a critical, diurnal role for rumination and rest, where most animals perform the behavior in the early morning and early evening (Shreffler and Hohenboken, 1980;da Cunha Leme et al, 2013). As such, longer, infrequent sampling intervals will accurately estimate lying behavior in confined ruminant animals (Chen et al, 2016;Pullin et al, 2017).…”

“…Previous literature has validated behavioral methodologies for other ruminant animals in confined environments, such as feedlot cattle (Mitlöhner et al, 2001), dairy calves (Miller-Cushon and DeVries, 2011), and dairy cows (Chen et al, 2016). To the authors' knowledge, only 1 prior study has validated behavioral observation methodologies for lambs housed on pasture (i.e., Pullin et al, 2017), and no studies have previously focused on lambs housed in a feedlot. Therefore, the objective of this study was to validate the accuracy of 4 different instantaneous scan sampling intervals (i.e., 5, 10, 15, and 20 min) compared with continuous sampling for lambs housed in a feedlot.…”