ORCID Profile
0000-0001-7684-4806
Current Organisation
Queensland Department of Agriculture and Fisheries
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Publisher: Elsevier BV
Date: 2017
Publisher: Elsevier BV
Date: 05-2007
Publisher: CSIRO Publishing
Date: 2016
DOI: 10.1071/AN14702
Abstract: PigBal is a mass balance model that uses pig diet, digestibility and production data to predict the manure solids and nutrients produced by pig herds. It has been widely used for designing piggery effluent treatment systems and sustainable reuse areas at Australian piggeries. More recently, PigBal has also been used to estimate piggery volatile solids production for assessing greenhouse gas emissions for statutory reporting purposes by government, and for evaluating the energy potential from anaerobic digestion of pig effluent. This paper has compared PigBal predictions of manure total, volatile, and fixed solids, and nitrogen (N), phosphorus (P) and potassium (K), with manure production data generated in a replicated trial, which involved collecting manure from pigs housed in metabolic pens. Predictions of total, volatile, and fixed solids and K in the excreted manure were relatively good (combined diet R2 ≥ 0.79, modelling efficiency (EF) ≥ 0.70) whereas predictions of N and P, were generally less accurate (combined diet R2 0.56 and 0.66, EF 0.19 and –0.22, respectively). PigBal generally under-predicted lower N values while over-predicting higher values, and generally over-predicted manure P production for all diets. The most likely causes for this less accurate performance were ammonium-N volatilisation losses between manure excretion and s le analysis, and the inability of PigBal to account for higher rates of P uptake by pigs fed diets containing phytase. The outcomes of this research suggest that there is a need for further investigation and model development to enhance PigBal’s capabilities for more accurately assessing nutrient loads. However, PigBal’s satisfactory performance in predicting solids excretion demonstrates that it is suitable for assessing the methane component of greenhouse gas emission and the energy potential from anaerobic digestion of volatile solids in piggery effluent. The apparent overestimation of N and P excretion may result in conservative nutrient application rates to land and the over-prediction of the nitrous oxide component of greenhouse gas emissions.
Publisher: Elsevier BV
Date: 07-2018
Publisher: Public Library of Science (PLoS)
Date: 24-10-2017
Publisher: Wiley
Date: 31-10-2012
DOI: 10.1111/J.1365-2915.2011.00981.X
Abstract: Species composition, seasonality and distribution of immature fly populations on a southern Queensland feedlot during 2001-2003 were determined. Similar data were collected on feedlots in central New South Wales and central Queensland. The fly species recovered in the highest numbers were Musca domestica L. (Diptera: Muscidae), Stomoxys calcitrans L. (Diptera: Muscidae) and Physiphora clausa Macquart (Diptera: Ulidiidae). Houseflies were the dominant species at all feedlots. Houseflies preferred the warmer months from October to June, but stable flies preferred the cooler months and peaked in spring (September-November) and autumn (March-May). Larval abundance ratings recorded in the feedlot and numbers of larvae extracted in the laboratory from corresponding s les followed similar trends. Larvae of M. domestica were most abundant in the hospital and induction area and least abundant in horse stables and yards. Pupae of M. domestica were abundant in the hospital and induction area and drains, but least abundant in horse stables and yards. Larvae of S. calcitrans were most abundant in drains and least abundant in horse stables and yards. Pupae of S. calcitrans were most numerous in drains and least numerous in old cattle pens. Feedlot design and management had little effect on fly reduction.
Publisher: CSIRO Publishing
Date: 2019
DOI: 10.1071/AN17388
Abstract: Feed waste in pork production sheds can amount to substantial economic losses. No simple methods exist to quantify this waste, which commonly ends up in the effluent stream. Monitoring piggery effluent might offer producers a practical alert solution for feed waste losses. We investigated piggery effluent pH as a potential marker of feed waste, given that most feed substrates and breakdown products are acidic whereas effluent is alkaline. To explore this prospective relationship, we constructed simulated effluent streams comprising faeces, urine and feed. These waste components were acquired from a commercial batch grower shed, at four different times over the 12-week growth cycle. In laboratory settings (25°C) we used the collected wastes to simulate the two stages of typical flushing piggery effluent systems: (1) Faeces + urine + feed waste accumulation in flushing channels, and (2) flush water mixing with these wastes in an effluent collection sump. We repeated the exercise for a one-off s ling event at a sow facility. For all events, at the grower and sow facility, the pH of the simulated effluents yielded exponentially decreasing relationships with increasing feed waste level (P & 0.05). For the grower facility we applied each of the four laboratory-derived relationships to the farm’s sump effluent pH, which was measured during each of these s ling events. The predicted feed waste levels were commensurate with estimates of feed waste for the same facility derived from alternative, time intensive approaches reported in other studies. Further work is needed to transition the promising results uncovered here into an alert system to help farmers improve profitability and minimise waste.
Publisher: Wiley
Date: 18-11-2012
Location: Australia
No related grants have been discovered for Alan Skerman.