Implementation of segregated weaner lamb management

Balla, Stephanie
University of New England


Neither an Abstract nor a Thesis was submitted. The following has been extracted from the application.

This project aims to investigate the potential of segregated management of Merino weaner lambs and the effects of this on wool and body growth. As such, the project is linked to the wool industry as it examines production as a result of modification to husbandry practices. Segregated management of animals displaying ill-thrift has been discussed in terms of potential production improvements, and this project provides the opportunity to deliver evidence in this field. The project will focus on the potential benefits of segregated management of weaner lambs in a grazing situation, with the intention of demonstrating the economic implications of managing poorly performing animals separately in a production system. This evidence can then be used in the future to create a management decision support tool for producers.

Segregated management of weaner lambs, with a focus on production, has been discussed with limited quantifiable results to date. With the increasing importance of economic efficiency, producers are seeking to improve productivity, as well as consistency, regarding the quality and quantity of their products. This project will investigate the feasibility of segregated management of weaner lambs, with the desire to have producers engage with the outcomes.

Project design;

The investigation will be conducted at CSIRO (Chiswick), outside of Armidale, NSW. 300 Merino weaner lambs will be separated into treatment groups. Groups will be allocated based on bodyweight (and/or weight from birth) and be balanced for sex, birth type and checked for sire group.

Three treatment groups will be formed:

  1. High bodyweight weaners – treated as per normal commercial best practice i.e. clean paddock, with good quality pasture.
  2. Low bodyweight weaners – treated with a clean paddock and good quality pasture, and also supplementary feed, for up to 4 months post-weaning. Shy feeders are to be identified using a colour feed marker. The group may be treated more frequently for internal parasites during this time.
  3. Control group – random selection of animals from both high and low bodyweight groups (prior to treatment commencement).

Animal measurements will be taken regularly throughout the trial. Weaners will be weighed periodically to determine if the low bodyweight treatment group will achieve similar weights to the high bodyweight treatment group. WEC will be monitored, and animals administered drench treatment correspondingly. Pasture will also be monitored for % green and DM kg/ha using the MLA pasture ruler. After the 4 month segregated management, the treatment groups will be combined and managed as one mob, for a further 3 months, until the event of shearing in August 2018. At this time, fleece measurements will be taken to compare treatment groups, in terms of greasy fleece weight and fleece diameter. It will also be assessed if the low bodyweight treatment group maintained performance without preferential treatment, and if the weaner mob is a consistent group in its entirety. These measurements will be assessed to determine the effect of weaner management on animal performance.