https://search.dev.ndltd.org/etd/massey/oai:mro.massey.ac.nz:10179/5246
type: CreativeWork
name: Shearing Merino ewes at different stages of pregnancy : some consequences for the progeny : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science majoring in Agricultural Science at Massey University, Palmerston North, New Zealand
description: Merinos are bred primarily for wool production, valued specifically for the fine-wool they produce. Wool returns have been diminishing over recent years so using management to improve wool quantity and quality is beneficial to growers. Shearing ewes at different stages of pregnancy has been shown to potentially influence the follicle population which in turn could achieve a finer, heavier fleece in the offspring, although this has not been examined in Merinos. A consequence of the diminishing wool returns is a greater emphasis on meat production, resulting in a shift in focus to increase live weight and body condition in order to increase reproductive performance and produce heavy lambs for sale. The whole Merino wool market is also currently threatened by the perception of overseas purchasers towards the practice of mulesing. Mulesing is undertaken in approximately half of New Zealand's Merino lambs as a means of reducing blowfly strike. There are few data available under New Zealand conditions for these pre-mentioned management factors that influence Merino production. Therefore, the aim of this thesis was to profile the live weight and body condition of single- and twin-bearing Merino ewes; investigate the effect of shearing time of Merino ewes on the live weight, fleece characteristics and the follicle population in their progeny; and to investigate the effect of mulesing Merino lambs on their live weight, dag score and fleece characteristics. Two hundred and ninety nine Merino owes were bred to 4 mature Merino rams on day 0 of the experiment (d0; May 20, 2006). Pregnant ewes were then allocated to one of three shearing times; mid-pregnancy (d106), late-pregnancy (d141) and post-lambing (d191). Ewes were weighed and condition scored on dO, d79, d106, d141, d191 and d283 of the experiment. The ewes produced 128 ewe-lambs which were used for subsequent measurements. Ewe-lambs were identified using DNA parentage testing to their dam's maternal shearing treatment. E…
abstract: Merinos are bred primarily for wool production, valued specifically for the fine-wool they produce. Wool returns have been diminishing over recent years so using management to improve wool quantity and quality is beneficial to growers. Shearing ewes at different stages of pregnancy has been shown to potentially influence the follicle population which in turn could achieve a finer, heavier fleece in the offspring, although this has not been examined in Merinos. A consequence of the diminishing wool returns is a greater emphasis on meat production, resulting in a shift in focus to increase live weight and body condition in order to increase reproductive performance and produce heavy lambs for sale. The whole Merino wool market is also currently threatened by the perception of overseas purchasers towards the practice of mulesing. Mulesing is undertaken in approximately half of New Zealand's Merino lambs as a means of reducing blowfly strike. There are few data available under New Zealand conditions for these pre-mentioned management factors that influence Merino production. Therefore, the aim of this thesis was to profile the live weight and body condition of single- and twin-bearing Merino ewes; investigate the effect of shearing time of Merino ewes on the live weight, fleece characteristics and the follicle population in their progeny; and to investigate the effect of mulesing Merino lambs on their live weight, dag score and fleece characteristics. Two hundred and ninety nine Merino owes were bred to 4 mature Merino rams on day 0 of the experiment (d0; May 20, 2006). Pregnant ewes were then allocated to one of three shearing times; mid-pregnancy (d106), late-pregnancy (d141) and post-lambing (d191). Ewes were weighed and condition scored on dO, d79, d106, d141, d191 and d283 of the experiment. The ewes produced 128 ewe-lambs which were used for subsequent measurements. Ewe-lambs were identified using DNA parentage testing to their dam's maternal shearing treatment. E…
author: van Reenen, Erica Helen
keywords: Sheep-shearing, Lambs, Merino sheep, Growth, New Zealand
date published: 2008
date modified: 2026-07-27T20:17:49Z
provider: Massey University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Massey University