At a microscopic level, wollastonite particles have an acicular structure. This means that they are composed of needle-like crystals. Many people are familiar with diatomaceous earth (DE) – the silicon-rich shell fragments of ancient marine life – and its pest control properties. Wollastonite has a similar effect: the needle-like calcium silicate crystals scratch and dessicate the skin and exoskeleton of insects and insect larvae. The advantage of wollastonite is that unlike DE which loses its “edge” when it gets wet, wollastonite retains its beneficial properties even in moist environments like soil, manure, bedding, and inside the digestive system. This leads to a number of potential applications in the livestock sector:
Cattle (Dairy and Beef)
Spread on floors, alleys, walkways, or added to stall bedding, wollastonite improves traction while balancing manure pH, potentially reducing odours and disease-causing bacteria. Wollastonite crystals can also dessicate fly larva, leading to reduced fly populations. Wollastonite will add calcium, magnesium, and silicon to the manure and adsorb phosphorus, increasing the fertilizer value of the manure or compost applied to fields.
Poultry producers are using wollastonite added to the bedding, or between flocks, as part of their disinfection and insect/mite control protocol. Growers report that chickens who ingest wollastonite appear to be in better overall health. Controlled feeding trials are currently underway in layers, broilers, and turkeys. Wollastonite will add calcium, magnesium, and silicon to the manure and adsorb phosphorus, increasing the fertilizer value of the manure or compost applied to fields.
Pork producers are experimenting with wollastonite to improve traction on slatted floors. In the manure pit, calcium silicate helps control odours, stabilize nutrients, adsorb phosphorus, and balance pH, creating a higher-value, lower-risk fertilizer for field application.
When added to bedding, wollastonite can help control external and internal parasites at various stages in their life cycles. Sheep farmers are beginning to experiment with wollastonite as a feed additive to aid in the control of internal parasites. Wollastonite will add calcium, magnesium, and silicon to the manure and adsorb phosphorus, increasing the fertilizer value of the manure or compost applied to fields.
Regulation and Oversight
Health Canada’s Pest Management Regulatory Agency categorizes calcium silicate as a “List 4A” formulant, the level of least concern, reserved for substances “which are generally regarded to be of minimal toxicological concern, as well as substances commonly consumed as foods.”
The U.S. Environmental Protection Agency considers calcium silicate to be exempt from the requirement for a residue tolerance level if used in accordance with good agricultural practices when applied to both growing crops or raw agricultural commodities after harvest and animals.