Possible Sheep and Wool Research Projects
Supervisor: Professor David Cottle
Interests: Sheep nutrition and wool characteristics • selective grazing behaviour • feed conversion efficiency • livestock systems and decision support tools • quantitative traits for sheep production • genotype by environment interaction • relative value of wool traits • wool supply chains.
Sheep nutrition and wool characteristics
Title: Is more fleece weight without higher diameter possible?
Co supervisor: L Kahn
Summary: Design of feed rations for Sharlea sheep aimed at economic production of superfine wool
Title: Wool quality in dual purpose/meat merinos
Co supervisor R Mortimer Centre Plus
Summary: Using @Risk Gross Margin spreadsheets to compare the economic performance of different dual purpose sheep enterprises, e.g. Centre Plus and Dohnes.
Selective grazing behaviour
Title: Sheep feeding preferences
Summary: : Sheep prefer to graze a mix of 70% clover: 30% grass when given free choice. Paradoxically, sheep which have a higher preference for clover can have lower clover (and protein) intakes as they may initially overgraze the clover. Dietary preference has a genetic component. Projects will study sheep dietary preferences versus their nutritional requirements and their possible incorporation into sheep and pasture breeding programs.
Feed conversion efficiency
Title: Feed efficiency and methane modeling - metabolic pathways- gene expression
Co supervisors: NSWDPI staff
Summary: Feed costs for maintenance are over 60% of the feed requirements of a flock/herd. Feed costs make up about 60% of production costs with protein and energy accounting for 90% of feed costs. Projects may include modelling the effects of management practices on methane production on farms to improve the maintenance efficiency of flocks/herds, studying the effects of feeding regimes on a range of metabolites (leptin, leptin binding proteins, adiponectin, Ghrelin, GLP-1, resistin, insulin, neuropeptides and hormones) in sheep with high and low breeding values for maintenance feed efficiency and developing models to describe variance in feed efficiency due to environmental and genetic influences.
Livestock systems and decision support tools
Title: Use of decision support tools, e.g. Grassgro3, SGS Pasture
Co supervisors: D Lamb, L Kahn (AIMS), K Mochany, (CSIRO PI), I Johnson (IMJ)
Summary: Case studies on Northern Tablelands properties and/or model development, e.g. incorporating FD, SS/SL/style, remote sensing validation, potential impacts of over grazing on soil parameters, nutrient loss and subsequent recovery, fodder crops, climate parameters/drenching impacts on internal parasite loads and stocking rate and grazing management choices.
Title: Managing spatial variability for increased pasture and livestock productivity in high rainfall grazing systems
Co supervisors: D Lamb, C Guppy, L Kahn (AIMS), C Walker (Incitec Pivot)
Summary: Refine protocols for acquisition and processing of remote- and proximally-sensed precision agriculture data relevant to livestock/pasture systems. Evaluate, then select, a range of decision support tools for integration of spatial data. Integrate biophysical sensing with productivity modeling and economic analyses. Precision management of fertiliser applications in livestock farming systems based on a suite of data collection and decision support tools (contingent on external funding).
Quantitative traits for sheep production
Title: New England Merino sire evaluation
Summary: Assessment of the progeny of fine wool rams (outliers/extremes for bare crutch, muscle Merino, high SGA EBV for wool-meat-reproduction-disease measured for standard and non-standard traits, e.g. feed efficiency, feed selectivity (pen feeding), temperament (box flight), stayability via conformation traits, drought tolerance (leptin etc.).
Title: Information Nucleus Flocks wool traits
Summary: Data from the Sheep CRC's information nucleus flocks will be explored for relationships between traits, the physiological basis of any relationships and implications for applied breeding programs.
Genotype by environment interactions
Title: Genotype by environment interaction corrections
Co supervisor: D Brown, AGBU
Summary: Classifying sheep grazing environments using various data, e.g. spatial data and studying the use of environmental classes in Sheep Genetics Australia breeding value analyses of wool traits.
Title: Mechanistic models
Co supervisor: A Wilson, SAC
Summary: Improving the prediction of GHG (methane) into the SGS Pasture model. Using the SGS mechanistic animal growth model to incorporate a description of the GHG genotype as represented by underlying biological traits that aim to specify the animal’s genetic potential for performance, independent of the environmental factors captured by the models. It can be argued that these traits may therefore be more closely associated to genetic potential, or components of genetic merit that are more robust across environments, than the environmentally dependent phenotypic traits (feed intake etc) currently used for genetic evaluation. The prediction of merit for underlying biological traits can be valuable for breeding and development of selection strategies across environments. Model inversion has been identified as a valid method for obtaining estimates of phenotypic and genetic components of the biological traits representing the genotype in the mechanistic model. Introduction of new biological traits that are less influenced by the environment than phenotypic traits currently used is possible by choice of growth pathways. Potential value comes from the estimation of underlying biological trait components and the explicit description of their expression across a range of environments as predicted by the model equations.
Relative value of wool traits
Title: Wool Market segmentation
Co supervisor: S Champion, Meat and Wool NZ; S Causer, Merino NZ
Summary: Analysis of relative economic values for wool in different product –process groupings and their changes over time and between countries.
Wool supply chains
Title: Wool Metrology projects
Co supervisor: T Mahar, AWTA
Summary: Metrology projects conducted in consultation with the Australian Wool Testing Authority.
Title: Virtual classer - case studies
Co supervisor: S Semple, NSWDPI
Summary: Using Virtual Classer software on wool clips to compare actual and optimized clip preparation practices.