Selcote Ultra

Selcote Ultra is a selenium granule which can be added when spreading fertiliser to supply selenium, through pasture, to livestock.

Selcote Ultra – the natural choice

Selcote Ultra granules have both fast and slow release forms of selenium. Upon application to the pasture, the fast release selenium is rapidly released and provides a quick boost to the pastures, which can be utilised by the grazing animals within days.

The slow release component releases selenites at a more gradual rate providing sustained pasture and animal selenium levels. Only a comparatively small amount of Selcote Ultra is required on each hectare as Selenium is a trace element and only required in parts per billion.

Using Selcote Ultra is a simple, convenient and cost effective way of ensuring your stock have sufficient levels of this essential trace element – all year round naturally through their diet.

Application Rates

Sheep / Beef / Deer Farms

Selcote Ultra should be applied at either 0.5kg/ha for 1 year supplementation or 1.0kg/ha for 2 years supplementation. The 1.0kg/ha application rate can last for 24 months because of the lower dry matter yield from these pasture types.

Dairy Farms

Because of the elevated dry matter production and higher soil activity levels in dairy pasture, Selcote Ultra should be applied at 1.0kg/ha for 12 months supplementation. While 1kg/ha is recommended for dairy farms, applications of 0.5kg/ha will provide a basal level of selenium above deficiency. There is however a growing trend to provide high-producing cows with selenium levels well above deficiency. Variations to application regimes, such as split season applications are possible. Higher rates than recommended should only be undertaken with close monitoring or veterinarian supervision.

Forage Crops

Because animals require selenium al the time, forage crops such as swedes, lucerne, kale, maize and cereals should also be treated. Application rates will vary from 0.5kg/ha to 1.0kg/ha depending on the amount of dry matter produced. Best results are achieved by applying to the drill row at sowing.


Selenium levels in supplements such as silage are as equally important as pasture levels. Selenium levels in silage can be boosted by early spring application to pasture or at sowing with maize silage.


For best results the entire farm should be covered at the recommended rates. Alternatively paddocks can be banded, provided the full quantity for each paddock is applied in the paddock and stock have free grazing access to the selenised pastures. In high country farms elevated selenium levels achieved on the flats will help stock through the key selenium requirement periods of mating, winter and lambing.

Easy application with Selcote Ultra

1. Spread with your spring or autumn fertiliser or applied nitrogen.

When ordering fertiliser specific the addition of Selcote Ultra (not just selenium). Selcote Ultra can be mixed on site during fertiliser application.

2. Self spread.

Selcote Ultra can be purchased from agricultural merchants and spread easily with a small bike/trailer mounted spinner. To help even coverage, add a little fertiliser to provide a greater bulk to spread.


Selcote Ultra is best applied prior to pasture growth periods i.e spring or autumn to coincide with fertiliser applications. Spring applications tend to give flatter pasture response curve while autumn applications can result in a peak selenium level the following spring. However because of the slow release properties, application timing is not critical. If stock are selenium deficient, Selcote Ultra should be applied as soon as possible to boost their selenium status.

Why should you use Selcote Ultra?

Convenience and Versatility

Selcote Ultra can simply be added to fertiliser. No stock handling, no labour requirement, and all your animals are supplemented. Alternatively Selcote Ultra can be easily applied direct with a small spreader to suit your individual requirements.

Effective & Proven

Selcote Ultra has for 17 years provided sustained assure selenium levels to New Zealand’s top farmers. Regular use means all your grazing stock have continued access to natural selenium source your pasture. No injection, no dosing or level worries and when you sell the stock the selenium investment stays on the farm.


Compare the cost of using Selcote Ultra to using other methods of selenium treatment. When you take into account application rates and ease of application, stocking rates, length of supplementation and no stock handling requited, Selcote Ultra is in a class of it’s own.


Selenium can be toxic if stock are given too much. Selcote Ultra has a 10-20 fold application error margin. Once Selcote Ultra is applied other supplementation methods are not necessary and should not be used. Selenium in drenches and vaccines is unlikely to be detrimental if used in addition to Selcote Ultra.

Beware of limitations

Selcote Ultra is the only slow release selenium grail available. Other selenium granules can give excessive initial levels and have a short pasture life. When you order insist on Selcote Ultra (not selenium) for both 12 month and 24 month supplementation – see Application Rate advice.

Talk to your agricultural merchant or fertiliser company when ordering your fertiliser.