Abstract:
Animal nutrition studies require large resource outlays for paddock and treatment replication to ensure treatment outcomes are valid. In addition to paddock variations there can be large variations in supplement intake if voluntary feeding is paxt of a treatment. To overcome these problems, a technique for trapping grazing sheep at the watering point each day was investigated. Two studies were conducted under dry seasonal conditions, one using pregnant ewes, the other using wethers. Two other studies were conducted under more favourable green pasture conditions, again with pregnant ewes and wethers. In each study, the sheep were educated to enter the yard surrounding the water trough through a trap consisting of two weldmesh panels, each 2m in length. Lucerne hay was used in the first week to coax the sheep between the panels and into the yard. After the education period, treatments were administered to sheep within a race inside the trap yard. In one dry season study some sheep were returning to the trap yard six to eight hours after release. A standard alarm clock was then installed to open this trap at 6.00 a.m., two to three hours before treatments were administered. This procedure was successful in that all sheep continued to be trapped. More than 98% of the sheep were trapped over the treatment period in both dry season studies. However, under green pasture conditions an average of 86% of pregnant ewes and <50% of wethers were trapped. Aversion to the treatments applied in the latter study may have been partly responsible for the poor trapping result which had followed a successful education period. Trapping during dry seasonal conditions offers several advantages for grazing experimentation.