An Investigation into the Fertilizer Potential of Slaughterhouse Cattle Paunch

Abstract

Abstract. In Australia, recycling of paunch waste to farmland has been suggested as a cost-effective and practicable environmental option, but little is known about its agronomic value. Experimental work was undertaken to assess potential risks due to weed seed contamination, determine the agronomic response of ryegrass ( L.) to soil incorporation of paunch, and investigate short-term greenhouse gas (GHG) emissions. Five types of paunch with compost ages between 2 and 16 weeks were compared with urea (46% N) and applied at field equivalent rates of 0 (control), 150, and 300 kg ha-1 N. The risk of weed contamination from paunch applied to soil appeared to be negligible; however, techniques that enable seed viability to be determined may be required to fully discard such risk. Average dry matter yield with paunch was ~30% higher than untreated grass, but ~35% lower than with urea. Dry matter yield in paunch-treated grass was between 2500 and 3250 kg ha-1 over five cuts conducted at 25-day intervals. Paunch N responses were between 1.12 and 3.25 kg DM kg-1 N depending on compost age, but lower than with urea N (~6.5 kg DM kg-1 N). Nitrogen use efficiency of paunch ranged between 3% and 20%, compared to about 35% with urea. Nitrogen fertilizer replacement value (NFRV) of paunch was highest in the 6-week-old compost (~60%) and ranged between 20% and 55% across all other organic materials. Short-term N2O emissions were similar (p > 0.05) with both mineral and organic amendments; however, CH4 emissions were higher (p < 0.05) from paunch compared with urea-treated soil. Overall, there appears to be potential for paunch-derived products to be used as a source of C and nutrients in crop production. Industry quality specifications for compost are available, but they need to be expanded to incorporate guidelines relevant to paunch. There is a requirement for the value proposition to industry to be determined, including reduced cost of paunch disposal via gate fees. Keywords: Byproducts, Composting, Fertilizer replacement value, Nutrient recovery, Nutrient use efficiency, Recycling of abattoir-derived waste.

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“…Further, the feasibility of spreading bulky organic products on-farm can pose additional costs compared to manufactured fertilisers. This includes increased energy use through fuel consumption, which was estimated to be up to three times higher for spreading organic materials such as cattle paunch, or through engaging external contractors to spread materials using specialised field equipment (Antille et al, 2018). Research is needed to substantiate the claims made about various products for farm productivity or carbon and natural capital sustainability metrics.…”

Process Optimisation of Anaerobic Digestion Treating High-Strength Wastewater in the Australian Red Meat Processing Industry

“…Co-substrate selection is likely to be determined based on the type of pre-existing technology available onsite, but co-digestion opportunities may warrant the installation of new and more appropriate technology which may enable treatment of currently under-utilised substrates. In the RMP sector, paunch (stomach contents) of slaughtered cattle consists primarily of grass and is commonly disposed of via three routes [56]: (1) removal of paunch and other solids from the site (2) material is composted on-site with use on-site and; (3) material is composted on-site and used off-site. Similarly, spent bedding from the pork industry is typically a straw or saw dust which is also commonly composted.…”