Pasture and Browse for Worm Control in Goats

Problem: Your goats are affected by worms most or all year-round and control is difficult to achieve.

Solution: Consider using plants that have anthelmintic properties (they reduce worm burdens) and including browse species as part or all of their diet.

Benefit: Some pasture and browse species, when grazed or fed as hay, can reduce worm burdens in goats. Browsing reduces a goat’s exposure to worms, because worm larvae cannot move more than 15 cm or so above the ground. Additionally, good nutrition allows goats to better resist and cope with worms.

Forage plants with anthelmintic properties

Most of these species are naturally high in tannins, and goats, unlike some other species, do not reject high tannin plants. While some high tannin plants have only marginal anthelmintic effects, others, such as sericea lespedeza, when used as the sole source of nutrition for a period, have resulted in good reductions of worm egg counts and worm burdens.

The most promising species showing some anthelmintic properties are

• temperate legumes such as sainfoin (Onobrychis viciifolia) in Europe, and sericea lespedeza (Lespedeza cuneata) in South Africa and USA
• tropical legumes such as Leucaena leucocephala in Australia, and Arachis pintoi, Gliricidia sepium and Cratylia argentea in Mexico
• heather species, Erica spp. and Caluna sp. (Ericeacae) in Spain
• chicory (Cichorium intybus) in Australia, New Zealand and the USA
• sulla (Hedysarum coronarium) (Asteraceae) in Australia and New Zealand

Forage plants with anthelmintic effects can be

• over-sown in pastures and eaten with grass
• grown as forage banks and coppiced to 2 metres,
• grown as monocultures in dedicated ‘worm control’ paddocks,
• offered as hay, silage or pellets. Goats are often browsed from as little as a week to several months.

The success of such a regimen for worm control depends on sufficient plant material being eaten by animals, and the type and concentration of plant active constituents, which will vary with climatic, soil, harvesting and processing conditions.

Moderate levels of condensed tannins in forages, in addition to anthelmintic properties, are thought to prevent bloat and protect protein against degradation in the rumen, but at high levels can lower fodder digestibility and palatability. Any alternate forage then must be of high nutritional value and high palatability, and easily cultivated and propagated.

Browse

Browsing effectively separates the goat’s mouth from worm larvae on pasture grass. If a goat is grazing with its head up, it will not ingest worm larvae, which are rarely higher than 15 cm on a pasture.

Thick stands of leucaena, tagasaste or native shrubs, with little grass between the bushes, provide good browse. Goats are, however, very rough on browse and can break branches or kill the whole plant by ringbarking. Careful management is needed to preserve shrubs.

Note that some of these species (e.g. leucaena) may become invasive.

References

• Crocker G. 2008. Sulla NSW DPI Primefact 745
  http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0019/212851/Sulla.pdf
• eXtension.org Goat Pastures Sericea lespedeza
  Goat Pastures Sericea lespedeza – Goats (extension.org)
• Neeson R. 2013. Condensed Tannins, their role in livestock nutrition and worm control. NSW DPI Organic News, Spring edition.
  http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0005/477959/Organic-news-Spring-2013.pdf
• NSW DPI 2000. Chicory Part A Summary. Agfact P2.5.40
  Chicory Part A – Summary
• NSW DPI 2005.Agnote DPI-398 Chicory (Chicorium intybus) Chicory (nsw.gov.au)
• Queensland Department of Agriculture and Fisheries. 2020. Leucaena (daf.qld.gov.au)