Factors Influencing Reproductive Wastage in Victorian Sheep Flocks

The cost to the national sheep industry of reproductive wastage has been estimated at around $839.6 Mil per annum (Jubb et. al. 2015). The Victorian sheep flock currently makes up 21$176.3 Mil each year. This thesis was developed to investigate the conditions which lead to reproductive wastage in Victorian sheep flocks through a review of the available literature and an investigation of data collected from commercial Victorian sheep flocks involved in the Sentinel Flock Project (DPI Victoria). Twenty flocks of prime lamb and wool producing sheep were initially enlisted across the sheep production areas of Victoria to monitor factors influencing reproductive wastage, morbidity and mortality over a three year period. One flock retired from the project and another flock was added hence 21 flocks were assessed. As far as possible, the spread of these flocks represented the distribution of sheep across Victoria. Flocks were enlisted from the known contacts of the Department of Primary Industries Victoria, Meat and Wool Services Branch. Target flock size was 400 – 3000 breeding ewes. Both commercial and stud flocks were eligible for consideration. The flocks husbandry, management, reproductive performance and procedures were monitored for a period of three years and documented to evaluate the incidence reproductive wastage and livestock deaths in the participating flocks. Deaths were investigated to establish cause. According to need, the investigation included on-farm necropsy and/or the submission of samples to the Gribbles Veterinary Laboratory for analysis and diagnosis. Over the course of this investigation there were 82092 ewes scanned for pregnancy status including reproduction rate. The mean conception rates (number of feotus scanned per number of ewes joined) for ewes over the years 2009 to 2012 across seasons of joining (Autumn/Spring lambing's) in this work were, for the Merino Ewe x Merino Sire (MXM) 116.9%, Merino Ewe X Prime Sire (MXP) 126.7% and Prime Ewe x Prime Sire (PXP) 145.7%. The mean lamb marking (lambs marked /ewe joined) percentages were for the MXM ewes 84.6%, MXP ewes 103.2% and the PXP ewes marked 118.6%. This equated to a total loss of 23726 lambs from ultrasound scanning through to lamb-marking and a further 1107 lambs were lost from lamb-marking to weaning. Of the lambs lost from ultrasound scanning to lamb-marking the largest losses were attributed to Starvation mis-mothering (48%) followed by dystocic birth (25%) then primary predation (7%) and there were 7% which could not be diagnosed due to the state of the lamb carcass. The ewes in this study were monitored throughout the years of this work to determine the cause of loss. There were 1421 or 1.7% of ewes recorded as dying over the 2009 to 2012 period of this work. Investigations were carried out on a sample n=209) of these ewes to determine the cause of death. The primary cause of loss was due to endemic infectious disease (34%) followed by obstetrical disease (26%), then metabolic disease (13%). There were 17% of the ewes submitted for necropsy which were unable to be diagnosed as to cause of death due to the condition of the carcass. In this work conception was under the control of BCS for the MXM and MXP but genotype of the sire was significant for the PXP grouping. Birth weight of the lamb which was to a large degree under genetic control was a significant factor in survival of the lamb

Defining Sheep Grazing Environments Using Remotely Sensed Data at a Range of Scales

The grazing environment (i.e. the quantity and quality of pasture available) drives sheep production in Australia. The long-term viability of the sheep industry is dependent on the sustainable use of pasture, which requires monitoring. Remotely sensed data have the potential to monitor changes in pasture resources within and between seasons. Remotely sensed data have the potential to; map pasture resources within a paddock, differentiate paddocks within a farm, differentiate farms within a region and differentiate grazing environments across the country. This thesis examines the application of remotely sensed data in the sheep industry at three scales (within a paddock, at the paddock/farm scale and at a continental scale). Data from a hand-held active sensor (Crop Circle™) were used to estimate green dry matter (GDM) within a paddock and produce a map that highlighted the variability within the paddock. The normalised difference vegetation index (NDVI) and soil adjusted vegetation index (SAVI) were used to estimate GDM in mixed annual and perennial swards over three years at two sites. Comparisons between NDVI, SAVI, pasture height and GDM indicated that producers should continue to use pasture height to estimate GDM but the Crop Circle™ could be used to map GDM variability within a paddock

Sheep Updates 2007 - part 4

This session covers eight papers from different authors: GRAZING 1. The impact of high dietary salt and its implications for the management of livestock grazing saline land, Dean Thomas, Dominique Blache, Dean Revell, Hayley Norman, Phil Vercoe, Zoey Durmic, Serina Digby, Di Mayberry, Megan Chadwick, Martin Sillence and David Masters, CRC for Plant-based Management of Dryland Salinity, Faculty of Natural & Agricultural Sciences, The University of Western Australia, WA. 2. Sustainable Grazing on Saline Lands - outcomes from the WA1 research project, H.C. Norman1,2, D.G. Masters1,2, R. Silberstein1,2, F. Byrne2,3, P.G.H. Nichols2,4, J. Young3, L. Atkins1,2, M.G. Wilmot1,2, A.J. Rintoul1,2, T. Lambert1,2, D.R. McClements2,4, P. Raper4, P. Ward1,2, C. Walton5 and T. York6 1CSIRO Centre for Environment and Life Sciences, Wembley, WA 2CRC for Plant-based Management of Dryland Salinity. 3School of Agricultural and Resource Economics, University of Western Australia. 4Department of Agriculture and Food WA. 5Condering Hills, Yealering. 6Anameka Farms, Tammin. MEAT QUALITY 3. Development of intramuscular fat in prime lambs, young sheep and beef cattle, David Pethick1, David Hopkins2 and Malcolm McPhee3,1School of Veterinary and Biomedical Sciences, Murdoch University, Murdoch, WA, 2NSW Department of Primary Industries, Cowra, NSW,3NSW Dept. of Primary Industries, University of New England, Armidale, NSW, 4. Importance of drinking water temperature for managing heat stress in sheep, Savage DB, Nolan JV, Godwin IR, Aoetpah A, Nguyen T, Baillie N and Lawler C University of New England, Armidale, NSW, Australia EWE MANAGEMENT TOOLS 5. E - sheep Management of Pregnant Merino Ewes and their Finishing Lambs, Ken GeentyA, John SmithA, Darryl SmithB, Tim DyallA and Grant UphillA A Sheep CRC and CSIRO Livestock Industries, Chiswick, NSW B Turretfield Research Station, SARDI, Roseworthy, SA 6. Is it important to manage ewes to CS targets? John Young, Farming Systems Analysis Service, Kojonup, WA MULESING 7. Mulesing accreditation - Vital for Wool\u27s Future, Dr Michael Paton, Department of Agriculture and Food WA, 8. Mulesing Alternatives, Jules Dorrian, Affiliation Project Manager Blowfly Control Australian Wool Inovatio

Diet has Minimal Impact on Australian Consumer Palitability

This study tested the palatability of lamb meat derived from pasture versus grain finishing systems. The loin and topside muscles from 105 lambs were collected. Sensory scores were generated using untrained consumers who tasted 5 day aged grilled steaks, scoring tenderness, juiciness, flavour and overall liking. Consumer scores did not differ in female lambs fed grain or pasture diets. However in wether lambs palatability scores for overall liking, tenderness and juiciness were higher for those on grain compared to those on pasture. Correcting for intramuscular fat accounted for most of these differences. These results confirm that Australian consumers do prefer grain-fed lamb meat, but only in wether lambs