Investigation into reducing odour emissions from partly loaded sheep vessels whilst in port

Summary

Dietary additives significantly reduced odour and ammonia emission from sheep urine and faeces mix. Gypsum consistently and significantly reduced ammonia emission from faeces and urine mix. Zeolite and, to a lesser extent, Yucca also had lower ammonia emissions but the difference was not significantly different from Control. All dietary additives (Yucca, Zeolite and Gypsum) reduced odour concentration by more than 50% at the 24 hour sampling point. None of the commercial bedding additives significantly reduced ammonia emission or odour concentration under the conditions described in this study.

Based on data from this study and published reports, we recommend Gypsum and Zeolite for testing on board shipping vessels. These products are relatively cheap and nonhazardous. In this study Yucca extract reduced odour concentration by 86%, but the published evidence shows contradictory results. Considering that there is some evidence of it improving animal performance (in poultry), it is worth considering this product for further study to find out (1) the cause of the mixed results observed in earlier studies and (2) the repeatability of its dramatic effect on odour concentration.

A long term solution to odour Control from livestock waste requires understanding the molecular-level mechanism of how the different additives work and how their effectiveness can be maximised. This is a major gap in our knowledge and deserves further research. The problems of livestock waste facing Live Export applies to all animal productions systems based on confined spaces (feedlots, piggeries, etc). We believe MLA/LiveCorp and PRDC can benefit from co-funding further research to find a solution to the problem of odour from livestock waste.