Potential for silvopastoral systems to control nematode burden in livestock farming in winter rainfall areas of South Australia, Australia

Hannah Griffiths* and Amanda (Mandi) N. Carr

Gastrointestinal nematode infections cause significant production losses in ruminants. In southern Australia, the estimated annual cost of internal parasites in sheep, cattle and goats are $436million, $82m and $2.54m, respectively. An over-reliance on anthelmintic treatments has resulted in anthelmintic resistance becoming an increasing concern for producers. Reducing the need for chemical anthelmintics is desirable to lower producer costs and limit the development of anthelmintic resistance. Condensed tannins found in many trees and forages are a plant secondary compound receiving considerable interest as an alternative anthelmintic strategy. Direct anthelmintic effects from condensed tannins are associated with the binding of larval proteins; slowing egg hatching, larval development and exsheathment. Indirect effects are associated with improvements to protein metabolism and immune function within the animal. Several native Australian tree extracts have demonstrated anthelmintic properties, but further research is required to assess their suitability for silvopastoral systems in South Australia.

Lay Summary

Gastrointestinal nematodes or ‘worms’, significantly lower both the physical well-being and economic profitability of livestock such as cattle, sheep and goats, in South Australia. There are concerns about parasite resistance with current chemical treatments and consumers are demanding chemical-free, sustainably produced food. Silvopastoral systems, where animals are grazed underneath or alongside trees, have many potential benefits to the animals and the environment. This review explores the potential effects of condensed tannins on worm burden and protein metabolism. Condensed tannins are found in the leaves of several types of plants, including trees and show considerable potential to reduce nematode burden in ruminant livestock by slowing parasite lifecycle, with a particular focus on egg and larval stages. Condensed tannins may also improve livestock protein metabolism or excretion. Several native Australian trees contain condensed tannins with the potential to reduce nematode burdens when used in silvopastoral systems.

Teaser Text

Condensed tannin ingestion by allowing access to tree forage in silvopastoral systems, has the potential to reduce gastrointestinal nematode burden in livestock by slowing the parasite lifecycle.

Keywords:

Published on: Sep 9, 2022 Pages: 118-126

Full Text PDF Full Text HTML DOI: 10.17352/ijvsr.000124
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