DIATOMACEOUS EARTH as an alternative treatment for internal parasites
By Dr Mackie Hobson BSc(Agric),BVSc

DIATOMACEOUS EARTH as an alternative treatment for internal parasites

The problem of Anthelmintic resistance and the poor acquired and innate immunity in Angora goats is a major problem when implementing roundworm control. For this reason, Mohair producers need to look at management strategies and alternative products when considering roundworm control.

Diatomaceous earth (DE), also known as Diatomite, has been used for many years as a natural de-wormer for animals. It has also been shown to:

• To be effective as an insecticidal treatment
• To have mineral benefits to enhance nutrition and growth.
• To improve heat tolerance in certain sheep breeds.

Are you looking specifically at Diatomaceous earth (DE) as an alternative treatment for INTERNAL PARASITES (Roundworms) in ruminants?

What is Diatomaceous earth (DE), also called Diatomite?

DE is a naturally occurring, silicon-rich sedimentary rock made up of fossilised remains of millions of diatoms, a type of hard-shelled plant algae originally deposited millions of years ago in the earth from dried up seas and lakes. The product is composed primarily of hydrated silica (silicon dioxide), with 10-16% other minerals, depending upon the source.

How does DE work to break the life of the roundworm?

One of the ways it works is that it breaks the roundworm life cycle by preventing the roundworm Larvae from moving from the faeces to the grass where they would normally be taken in by the ruminant.

Having an impact on the life cycle, the parasitic burden on the pasture would decline over time and so reduce the uptake and parasitic burden carried by the ruminant. (Laing et al. 2013, Baloyi 2011, Beltran and Martin 2015, Islam et al. 2016).

One theory states that because DE has small, sharp edges, its abrasive action scratches off the waterproof coating of the insects and absorbs lipids from the waxy outer layer of their exoskeletons, causing them to dehydrate and die.

Another theory is that DE acts as a buffer in the stomach, thereby creating an unsuitable environment for the feeding and reproduction of the parasites (Köster, 2010).

What have studies concluded about DE as a treatment for internal parasites in ruminants?

• El Gayar et al. (2002) on pen-fed does artificially infected with Haemonchus contortus. DE treated animals had lower faecal egg counts compared to the untreated does

• McLean et al. (2005) reported that cattle and sheep that received a DE supplement had low faecal egg count (FEC) for the duration of the experimental period was, similar to animals treated with an anthelmintic. This study suggested DE may offer some benefits in controlling internal parasites.

• In a study with goats by Gregory et al. (2009), DE did not show any significant effects on the parasite
• In a study by Osweiler & Carson (1997) with grazing lambs, no significant difference in FEC and abomasal gastro-intestinal larval counts were found in control vs DE-fed lambs.
• In a review article, Whitley & Miller (2015) concluded that most controlled studies with published results including sheep, goats, and cattle, have noted no significant impact of DE products on gastrointestinal nematode infection indicators.

• In a Grootfontein trial, T. Nkwana et al. (2019) on lambs involved DE in their diets at different levels concluded that the DE did not significantly reduce parasite loads as measured by FEC. (Coccidiosis and Roundworm counts).

• Moore et al.(1995) indicated that DE did not provide control of gastrointestinal nematodes.

• Bernard et al. (2009) confirmed no significant reductions of faecal egg counts in sheep.

• In a review article, Dr Niki et al. concluded information about the use of this product for gastrointestinal nematode control is sparse and unconvincing. The majority of controlled studies with published results, including sheep, goats and cattle, have noted no significant impact of diatomaceous earth products on gastrointestinal nematode infection indicators.

• Fernandez et al., 1998 found no positive effect of DE research conducted with feedlot steers in 1996.

• Ahmed et al., 2013 concluded there was no effect on faecal egg counts, although the author reported differences in treatments for larvae per gram of faeces.

• Bowie, 2014 concluded that faecal egg counts decreased with time for 11 days after treatment for lambs but were not significant for ewes.

• Nuti et al. (2000) stated there were no differences among treatment groups for faecal egg counts or packed cell volume but estimated survival was significantly lower for untreated than for treated animals.

There is certainly debate by different researchers as to the direct use of Diatomaceous earth (DE) as a gastrointestinal nematode treatment. However, the impact on the larvae as a control mechanism to reduce pasture contamination and larvae uptake and the additional benefits of growth and production must be considered. 

REFERENCES:

Effects of fossil shell flour supplementation on heat tolerance of dohne merino rams Lwazi Mwandaa, Olusegun O Ikusikaa,b,⁎, Conference T Mpenduloa, Anthony I Okohb,c

THE EFFECT OF DIFFERENT INCLUSION LEVELS OF DIATOMACEOUS EARTH IN FEEDLOT DIETS ON THE PERFORMANCE OF LAMBS A.T. Nkwana1,2, J.H. Hoon1# & P.J. Fourie2 1 Grootfontein Agricultural Development Institute, Private Bag X529, Middelburg (EC), 5900 2 Department of Agriculture, Central University of Technology, Private Bag X20539, Bloemfontein, 9300

Köster, H., 2010. Diatomite in animal feeds. Animate Animal Health.

McLean, B., Frost, D., Evans, E., Clarke, A. & Griffiths, B., 2005. The inclusion of diatomaceous earth in the diet of grazing ruminants and its effect on gastrointestinal parasite burdens. In: International Scientific Conference on Organic Agriculture, Adelaide, Australia, 277-280.,

Gregory, B., Mulumebet, W. & Mohamed, A., 2009. The effects of diatomaceous earth on parasite-infected goats. Bull. Georg. Natl. Acad. Sci. (3)1, 129-135.

Osweiler, G.D. & Carson, T.L., 1997. Evaluation of diatomaceous earth as an adjunct to sheep parasite control in organic farming. Leopold Center Completed Grant Reports, 102.

Moore, G.A., A.M. Zajac, C.D. Thatcher, D. Notter and S. Umberger. 1995. Use of diatomaceous earth in the control of internal parasites of grazing lambs. Proceedings of the American Association of Veterinary Parasitologists meeting. 40:66-67.

Bernard et al. (2009) The Effects of Diatomaceous Earth on Parasite Infected Goats.Authors: Gregory C. Bernard   Tuskegee University Mulumebet Worku     North Carolina Agricultural and Technical State University, Mohamed Ahmedna   Qatar University

Dr Niki C. Whitley and Dr James E. Miller, North Carolina Agricultural and Technical State University, Greensboro, NC, USA

Fernandez, M. I., B.W. Woodward and B.E. Stromberg. 1998. Effect of diatomaceous earth as an anthelmintic treatment on internal parasites and feedlot performance of beef steers. Animal Science. 66:635-641. DOI: 10.1017/S1357729800009206

Ahmed, M., M.D. Laing, and I.V. Nsahlai. 2013. Studies on the ability of two isolates of Bacillus thuringiensis, an isolate of Clonostachys rosea f. rosea, and a diatomaceous earth product, to control gastrointestinal nematodes of sheep. Biocontrol Science and Technology. DOI:

Bowie, E.A. 2014. Alternative treatments for Haemonchus contortus in sheep: Testing of a natural dewormer and literature review of management. Dickinson College Honors Thesis. Paper 163.

Nuti, L., B. Johnson, D. McWhinney. N. El-Sayed, and T. Craig. 2000. Is there any effect by dietary diatomaceous earths in the control of gastrointestinal nematodes? Proceedings of the American Association of Veterinary Parasitologists meeting. 45:50.

El Gayar, A., T. Craig, J. Thompson, B. Johnson, D. McWhinney and L. Nuti. 2002. The effect of protein levels and diatomaceous earths on Haemonchus contortus challenge in goats. Proceedings of the American Association of Veterinary Parasitologists meeting. 47:53-54.