Abstract | This paper alleges that information necessary to make management decisions, such as calving date, and improved precision in estimating characteristics of an individual cow's liveweight profile can be obtained when liveweights taken frequently and automatically are compared to liveweights taken at greater than 27-day intervals using conventional methods. The measurement, liveweight, is used to evaluate biological and economic components of production animal agriculture. Changes in liveweight are dynamic, both diurnally and seasonally, mainly in response to body fluids anti fill (Anderson and Tietjen, 1982). To reduce variability in the mean liveweight between animals, past research has been directed to evaluate number of animals to be weighed, time of weighing, type and length of fasting, and the use of consecutive weighings (Hughes, 1976). Until the advent of single animal electronic scales and individual electronic animal identification, frequent weighing of free ranging cattle was not practical (Anderson, Landt and Salazar, 1981). Automatic liveweight data acquisition reduces the incidence of transcriptional and phonetic errors and variability in data taken during manual weighing arising from nervous animalsthat move excessively on the scale platform. Analyses in this paper compare liveweight data of free ranging cattle obtained when both infrequent manual and automatic weighings were recorded. Prior to drinking, automatically obtained individual liveweights were taken whenever animals entered the corral to drink water. |