Natural alternatives to antibiotics in stockfeed may be on the menu for sheep and cattle if new research is confirmed.
CRC Salinity postgraduate student, Pete Hutton, has discovered that two Australian native plants have similar effects in a test tube to antibiotics in preventing lactic acidosis, a digestive disorder of ruminants.
Ongoing research is being conducted with the aim of providing replacement of antibiotics in some stockfeeds by a clean, green alternative.
?Antibiotics are used in stockfeed to increase growth rates and production,? Pete said. ?As far as we know this practice remains safe, but there is a perception that it will lead to development of resistant organisms that could harm human health.?
From 1992 to 1999 Australia imported more than 700 tonnes of antibiotics each year, with nearly 400 tonnes going into stockfeed and around 50 tonnes for veterinary uses. This was much greater than the 250 tonnes used by humans. More recent statistics are difficult to obtain.
The European U_nion banned the use of many antibiotics in stockfeed in the late 1990s, particularly those also used in human medicine. A total ban has applied from January 2006 in the EU and intensive livestock producers in other countries including Australia will be under pressure to follow suit to gain entry into European markets.
It has been known for some time that some Australian native plants can selectively inhibit microbes in a similar way to antibiotics. Pete?s objective was to find plants that inhibit the microbes responsible for lactic acidosis, at present controlled by adding small doses of specific antibiotics to feed.
He has so far screened 110 plants from a very long list of candidates, and found two that have similar effects to antibiotics when tested in the laboratory. One plant showed a level of anti-microbial activity very close to that of current antibiotics.
?Consumer perception is that returning to ?natural products? such as grazing plants rather than administering antibiotics is very attractive,? Pete said.
?At the moment we don?t know the mode of action of the chemicals in the two plants, so the next steps are feeding trials and then isolation of the active compounds that are inhibiting the bugs.?