Validating the use of pen scores to capture behaviors expressed by cattle unrestrained in a pen1.

Abstract

Many subjective methods exist to assist producers in evaluating temperament. Use of a pen test, which allows behavior to be observed in a non-restrained setting, may be an effective method to evaluate temperament by allowing more variation among animals to be expressed as compared to a restrained test. The objective of this study was to analyze video recordings of penned calves to determine whether the repertoire of behaviors they expressed were adequately captured by their individual (IPS) and group (GPS) pen scores. In each of 3 yr, 40 predominantly Angus commercial Bos taurus heifers, 2-wk post weaning, were assessed monthly in 3 consecutive months (recording periods). After routine handling through a weigh crate and squeeze chute, each heifer was released individually into a pen (12 x 6 m). Their response to 30 s of human presence within the pen was evaluated. They were then joined in groups of four in a larger (12 x 8 m) pen and re-evaluated for 30 s in a group setting. An IPS and GPS was assigned using an ethogram ranging from 1 (docile) to 6 (aggressive). This interaction was also video recorded. Using the videos, the explicit behaviors captured by each pen score were investigated using Noldus Observer software. Data were analyzed with ANOVA using SAS. Within each recording period, the concordance of pen scores with the repertoire of behaviors expressed were compared. In the group setting, heifers could not be clearly distinguished on video and were instead assigned the average GPS of the group. Heifers with higher IPS and average GPS categories had larger flight zone sizes and reached faster paces for longer periods of time. Furthermore, heifers with lower IPS appeared more neutral to the presence of a human and moved around less often. Ethograms for pen score successfully delineated the temperament of heifers. The use of such scores can provide a valuable on-farm assessment of cattle behavior during routine handling.