Dr Stephan Tait
Dr Stephan Tait, who succeeded Dr Rob Wilson on July 1 as Leader of Pork CRC Program 4 ‘Carbon conscious nutrient inputs and outputs’, has been actively involved in the CRC for High Integrity Australian Pork, with specific strategic advice, coordination and collaboration within the ‘Carbon neutral pork production’ Subprogram.
This Subprogram encourages novel research and development to maximise methane production from effluent ponds to reduce carbon emissions, together with effective on-farm utilisation of the gas for heat and power.
Stephan, who has a Bachelor of Engineering and a PhD in Chemical Engineering from University of Queensland, was awarded a Pork CRC Research Fellowship in 2012 to lead the Pork CRC’s Bioenergy Support Program, which has successfully encouraged and promoted commercial on-farm uptake of renewable energy production and use and nutrient recovery utilisation from waste technologies in Australia and New Zealand.
Currently, around 18 biogas systems are established across Australia. The reduction of GHG emissions from just seven farms contracted under the Federal Government Emissions Reduction Fund, has abated 0.5 million tonnes of CO₂, worth $7.1 million in carbon credits.
Stephan’s enthusiastic extension of R&D outcomes to the commercial pork industry and the practical on-farm adoption of novel technology via two early adopter demonstration farms, has been the key to the success of this support program.
He has also been instrumental in four pilot to full scale technology testing programs, in conjunction with some of the largest pork producers in Australia.
A significant contribution by Stephan with Australian Pork Limited has been through communicating with and educating federal government regulators on the technical aspects of renewable technologies and projects associated with the Carbon Farming Initiative.
Stephan has also facilitated workshops with gas safety regulators across Australia, which led to the development of practical on-farm safety policies and regulations for the adoption of biogas production and use in agriculture – Code of Practice for on-farm biogas. Regulators have recommended this code be included in some state-based safety legislation and it has been proposed as a likely future Australian Standard.
Stephan has also co-authored new design guidelines for anaerobic ponds which are now utilised by more than 60% of Australian pork farms.
His research has focused on the utilisation of waste streams and wastewater as an energy source, nutrient recovery and water re-use, with a particular emphasis on agricultural wastes.
Stephan is involved is a number of large research projects funded by Pork CRC, APL and collaborating rural RDCs, commercial and government institutions and Federal Government. These have attracted about $1million in external funding and cover diverse research areas, including the understanding of the biology of anaerobic systems, development of low cost solid waste digestion and nutrient recovery, enhanced energy recovery through anaerobic co-digestion, low cost biogas purification and gas safety requirements. Stephan also supervises PhD and Masters students through these projects.
Stephan was Project Leader for an $840,000 project, ‘Anaerobic treatment for emissions reduction from solid manure residues’, with the Federal Government’s ‘Filling the Research Gap’ under the National Agricultural Manure Management Consortium. This was co-funded by Pork CRC, Australian Egg Ltd and a commercial supplier of bioenergy and engineering infrastructure.
Other waste to energy projects include:
- Waste to Revenue: novel fertilisers and feeds (APL).
- Fertilisers from piggery liquid and solids via nutrient extraction and solid formulations (APL).
- Enhanced energy recovery in Australian industry through anaerobic co-digestion (Pork CRC).
- Enhanced methane production from pig manure in covered lagoons and digesters (Pork CRC).
- Assessing stimulation and inhibition of anaerobic lagoons (Pork CRC).
- Bio-upgrading piggery biogas by growing algae for value-add end uses (Pork CRC).
- Assessment of low cost biogas purification media (Pork CRC).
Two further collaborative projects were:
- On-farm evaluation of a pond-less piggery treatment system.
- Options for cost effective and efficient use of piggery biomass energy.
A significant development has been a safe method for biological scrubbing of methane produced from effluents to eliminate hydrogen sulphide. This has resulted in a significant reduction in the cost of removing H₂S from biogas and is now being considered, and in one situation accepted, by a State Fuel Gas Safety Regulator. The method was developed from on-site testing, fine-tuning and collaboration at the two Bioenergy Support Program demonstration sites and is now being used at on-farm scale biogas projects.
Although essentially a research-focused academic, Stephan dedicates much of his time and energy developing and delivering a range of undergraduate, postgraduate and professional development course materials for technology transfer and industry use.
Stephan is a popular and regular contributor to the annual Pork CRC supported Roseworthy, SA, course, ‘The Science and Practice of Pig Production’, this year attended by 35 people, including pork industry and farming personnel, postgraduate students and undergraduate students.
Stephan also contributed a column, “It’s a Gas”, highlighting new research and development, in Australian Pork Newspaper.
Technology feasibility reviews have been undertaken for piggery clients across Australia, from desktop findings and recommendations to technology testing and on-farm adoption.
Stephan has also contributed to the Pork CRC/APL ‘Roadshow’s across the country, delivering to grass-roots producers the results from his research and answering site-specific queries about the adoption of biogas technology. Stephan and his students are regular contributors to industry scientific conferences and events, including Australian Pig Science Association, Pan Pacific Pork Expo and Bioenergy Australia.
According to Dr Rob Wilson, Stephan’s quiet and unassuming approach to significant industry issues has gained him the respect of the smaller family farm operators and the large integrated pork enterprises.
Dr Wilson, who said he was confident Stephan would do an excellent job leading Pork CRC Program 4, has outlined below some outcomes and directions for the three Subprograms.
4A – ‘Future Feeds For Future Needs’
Dr Navid Moheimani’s research team at the Algae R&D Centre at Murdoch University, WA, has successfully isolated two macroalgae species that can grow on diluted anaerobic digestion piggery effluent (ADPE), containing up to 250mg Nh4 nitrogen per litre. The biochemical composition and chlorophyll content of the macroalgae has been analysed and biomass productivity using algal mats in a new bioreactor is now being studied.
Navid’s group has also investigated the growth of microalgae in ADPE, using tubular photobioreactor and open ponds. Both systems were successful in treating ADPE using microalgae of which Chlorella sp. was the most dominant, but overall there was a 2.1 increase in biomass productivity in the Biocoil compared to the raceway pond. There was no differences in the ammonium removal rate however between the two treatment systems.
4B – ‘Enhanced Use Of Traditional Protein And Energy Sources’
While earlier Pork CRC projects showed that reducing milled grain particle sizes improved feed efficiency for weaner and grower pigs, a large program (4B-112) followed this work to investigate and optimise particle size distribution for grains and protein sources. Led by PhD student Giang Nguyen, together with Dr Peter Sopade and Prof Michael Gidley at University of Queensland, the project has concluded and the final report is being reviewed by Pork CRC.
The project showed particle size management continues to be an important and potentially overlooked aspect of feed quality. A prototype hand-held on-site sieving device offers the potential for on-site adjustment of milling parameters, in particular to reduce the levels of particles larger than 1 mm.
Further investigations continue with project 4B-124, which is looking at the potential to re-engineer grain grinding and/or sieving equipment in commercial feedmills.
4C – ‘Carbon Neutral Pork Production’
Alan Skerman at Queensland Department of Agriculture & Fisheries is providing practical and essential information to producers interested in biogas through the Bioenergy Support Program, with ongoing support from Dr Stephan Tait. Alan has updated the list of biogas equipment and service suppliers and has successfully completed the first methane potential analysis of effluent samples from a southern Queensland producer using the AMPTS 11 testing equipment.
Pork CRC project 4C-109 is looking to enhance methane production in covered ponds and digesters using the inhibition test developed in an earlier project (4C-105), has shown that the observed inhibition was considerably less than expected than from acute inhibition, being only 45 – 55%. High ammonia, nitrogen or sodium levels would have been expected to inhibit around 90% of biogas organisms. This suggests microbes could be much more resilient when exposed to inhibitors over extended periods of time, even if the inhibitor concentration is high. Microbial concentration analysis is continuing to clarify whether the microbial community is similar to that in the control digester or if the promoted resilience has resulted in a unique microbial population.
Pork CRC project 4C-117 was the first to establish a life cycle assessment of greenhouse gas emissions across the Australian pork supply chain. A comprehensive and fascinating report.
For further information, contact Dr Stephan Tait, Tel (07) 3346-7208 or Email email@example.com
Subprogram 4B: Enhanced use of traditional protein and energy sources
Pork CRC Subprogram 4B leader is research management consultant Dr John Black AM, FTSE, FAIAST, a fifth generation Australian born in Omeo, east Gippsland, Victoria. With his mother a grazier’s daughter and his father a civil engineer, John developed a strong interest in agriculture and science long before completing his Agricultural Science degree and PhD at the University of Melbourne.
John regards one of the major achievements from Pork CRC Subprogram 4B as the development and commercialisation of near infrared (NIR) technology for rapidly measuring the chemical composition, digestible energy content and intake probability of cereal grains for pigs. NIR calibrations are also being developed to rapidly measure total lysine and biologically active (reactive) lysine content of canola and soybean meal, which vary widely, depending on the oil extraction procedures. Subprogram 4B has also assisted in breeding and commercialising of two varieties of field pea (Maki & Walana) for northern pig regions and a triticale (Berkshire) for southern regions.
Another major outcome of the Subprogram has been the observation that digestion rate of starch and protein in milled grain or pulse samples decreases with the square of particle size, meaning a doubling of particle size decreases the rate of digestion four-fold. This finding has major significance for the pig industry because large feed particles pass undigested from the small intestines and are fermented by microbes in the hind-gut. Fermentation of feed results in 15-20% of the digested energy being unavailable to the pig and is lost as heat, methane and voided microbes. Experiments show that removal of large particles by sieving, regrinding and adding them back can improve feed conversion efficiency by more than 20%. A simple, hand-held sieve developed with Pork CRC support has revealed that most feeds milled for pig feed have excessive amounts of large particles.
John’s University of Melbourne PhD, Utilisation of protein and energy in growing lambs, was directed to defining the protein requirements of young sheep as previous attempts had given a huge range in estimates. At that time (mid 1960s), the significance of rumen microorganisms modifying the nature of ingested nutrients was relatively new knowledge. It was clear that previous estimates of protein requirements depended on the protein sources used in the experiments and the degree they were degraded in the rumen. Consequently, John adopted a novel approach for the time, to first determine the protein requirements of the lamb’s tissues and then account for the effects of microbial activity in the rumen on the supply of amino acids and energy to the tissues. Milk based diets varying widely in their protein and energy content were infused with peristaltic pumps into the abomasum (simple stomach) of the lambs as their sole diet. This technique allowed the rumen to be bypassed and nutrients were digested as in a simple stomached animal. The result was the first thorough understanding and description of the interrelationships between protein and energy supply to the tissues and protein and fat deposition in domestic animals.
The last experiment in his PhD investigated the effects on protein and energy utilisation when the same amount of a milk based diet was given into the rumen or abomasum of lambs offered a roughage diet. The differences in protein and energy deposition resulting from the two treatments was large, demonstrating the extent to which milk was degraded by microbes in the rumen.
His PhD had a major impact on the rest of John’s career in three ways. He firstly had to understand and explain the reasons for these large differences in nutrient utilisation between the rumen digestion and simple stomach-small intestine digestion. This required the integration of biochemical and physiological knowledge from many sources into a quantitative analysis – the genesis of mathematical modelling being such a strong part of his subsequent professional activities.
Secondly, he realised that all mammals with more than one stomach chamber needed to have a reticular groove (two muscular folds that make a tube from the oesophagus to the simple stomach whenever an animal suckles) to prevent loss of nutrients in milk from microbial fermentation in the other stomach chambers.
The third significant event was Dr Tony Dunkin’s appointment as director of the new pig research centre at the University Melbourne while John was studying his PhD. John and Tony had many discussions about the research and biological principles, resulting in a similar approach used in the milk-fed lamb studies being adopted to understanding relationships between protein and energy utilisation in pigs and the subsequent PhD work of Ian Williams and Roger Campbell.
John spent many years at the CSIRO Division of Animal Physiology (later Division of Animal Production) in Sydney, where he became a Chief Research Scientist, Assistant Chief of the Division and OIC of the Prospect Laboratory. At CSIRO he continued research into amino acid and energy utilisation in sheep for both body and wool growth, collaborating with others to develop fundamental computerised mathematical models integrating biochemical and physiological information for grazing sheep and for partitioning nutrients between body functions. A major focus throughout his career has been to understand the reasons for biological observations and to describe these mathematically in an integrated system.
At CSIRO John continued an association with Tony Dunkin to help refine the protein energy relations in pigs and prove there was a ‘break-point’ in the relationship. Finally, this association led to the development of AusPig, which remains the most comprehensive mathematical description available for predicting nutrient utilisation in pigs and the likely economic outcome from a wide range of management practices. John continually upgraded AusPig, which now includes utilisation and loss of all major minerals and greenhouse gases.
After leaving CSIRO, John started his research management consultancy and has managed research projects for many RDC’s and private companies. His major objectives are always to ensure that research by these organisations does not repeat earlier work, that it moves towards providing new technologies (because he believes all significant developments within industries arise from new technologies or new applications of technologies) and that systems are developed to aid adoption of knowledge. John has worked with several R&D groups to develop a knowledge adoption procedure that ensures only those management processes that have a major impact on productivity and profitability are undertaken and a methodology is established to ensure they are undertaken correctly and consistently over time.