Back Inoculate your maize silage, choose wisely

Date: 15 February 2017

Maize silage harvest is running 2 - 3 weeks late in most areas as a result of later planting and cooler than average early summer temperatures. Now is a great time to ensure you are ready for maize silage harvest. The usual checklist applies. Clean out your stack or bunker to remove the residues of last year’s crop, make sure there is good access for harvesters, tractors and trucks, liaise with your contractor and order silage making supplies including silage covers, tape and inoculant.

Inoculant is an important part of the silage making process. Maize silage inoculants fall into two general categories – those which improve fermentation resulting in lower losses in the stack, and those which reduce heating resulting in lower losses when the stack is exposed to the air at feed-out time.

What type of product should I use?

If your stack management is really good (i.e. the face is always kept tight and you have a narrow stack and a high feed-out rate) or you are planning to feed out your maize silage immediately after harvest, a fermentation-enhancing product (e.g. Pioneer® brand 1174 or 1132) is the best choice. Aerobic stability products (which reduce heating at feed-out time e.g. Pioneer® brand 11C33) are a great option if your bunker has a relatively wide face and/or you like to fill the feed-out waggon the night before.

Choosing an inoculant brand

There are a number of inoculant brands on the New Zealand market, so which one should you choose? There are a few important things you should always look for:

  1. Guaranteed bacteria numbers. Independent experts agree that for an inoculant to be effective, it should contain enough live bacteria to allow an application rate of at least 100,000 cfu per gram of forage. Products with higher bacteria numbers are not necessarily better as some strains multiply more quickly and are more competitive than others. An independent study published in the US Journal of Dairy Science showed that a competitor product applied at 800,000 cfu/gram of forage didn’t keep silage cooler than Pioneer® brand 11C33 applied at 100,000 cfu/gram1.
  1. The right bacterial strains. Most farmers would never buy cheap semen from unproven bulls to produce replacement heifers. Why? Simply because they don’t know what they are getting. The resultant progeny may milk well and be of even temperament, or they could be low performers who climb out of the bale. In the same way, don’t buy a cheap, unproven silage inoculant (or additive) because you don’t know what you are getting.

A paper presented at the New Zealand Grasslands Association conference1, compared the aerobic stability of eight different maize silages inoculated with three commercially available silage inoculants. Pioneer® brand 11C33 inoculated silage stayed cooler 55.5 hours longer than the untreated control. There was no significant difference between silage treated with other products and the untreated control2.

  1. Good technical back-up. I am a firm believer in the value of technical back-up. It allows you to extract the most value out of the products you use, and is invaluable when things don’t work as they should. Choose a company which have knowledgeable local staff who can assist you to get the most out of your investment in their inoculant products.


Make the most out of your maize silage this year by applying a proven silage inoculant. All the best for the harvest season!



1Huisden et al, 2009. Effect of applying molasses or inoculants containing homofermentative or heterofermentative bacteria at two rates on the fermentation and aerobic stability of corn silage. J. Dairy Sci. 92:690–697

2Kleinmans et al, 2011. Using silage inoculants to improve the quality of pasture and maize silage in NZ. Proceedings of the NZ Grassland Association 73: 75-80


Ian Williams

Forage and Farm Systems Specialist