Greater dependence on maize silage means close attention to variety choice is even more important

Kevin Bloomfield, who farms the 89ha Choon Farm on the Lizard Peninsula has grown maize for several years and the crop is taking on a greater importance as he moves to block calving with his 130 cow herd.

The move from all year round calving is designed to simplify the overall system and improve use of grazing and milk from forage.  The farm is prone to drying out and grass can be in short supply in the late summer.

“By calving from August onwards we can bring cows straight onto winter rations and move them out to grass in the spring when they are safely in calf,” Kevin explains.  “They will be drying off as grass runs short.

“Our aim is to feed a consistent diet at peak lactation and while cows are being served as this gives fewer problems than having to manage variable quality grazing, as was often the case when we calved all year round.”

The winter diet is a TMR comprising maize and grass silage, fodder beet, barley and a 40% protein blend.  In previous years, maize has not been available as cows were housed so the diet would initially contain higher proportions of grass and fodder beet.  The aim now is to increase maize production to allow feeding all year round.

In 2015 Kevin grew 13ha, an increase on 2014.  In 2016 he plans to grow around 16ha.

“This year we harvested 600 tonnes which means we will have some for buffer feeding as well as silage available to use with fresh calvers in August and September before we can add the 2016 crop to the diet.  As we are growing a greater proportion of maize, we must be sure we maximise the tonnage of quality feed available and that it can be harvested in time, making variety choice a crucial management decision.”

Kevin explains it is important to get maize planted early so is looking for good early vigour.  He also needs an early maturing variety to ensure the crop dries down quickly.  He says that being close to the coast in Cornwall he sees very little drying down of maize after mid-October.

“We won’t consider anything later than maturity class 10 but also want a variety that will deliver good yields of high quality silage with a high energy content and good starch levels.  We used to grow 3-4 varieties but I think that the fields being used have far more influence on how the crop will perform and now will grow a single variety.”

Variety selection is a discussion with Alan Moore from ACT who explains that after trialling the variety in 2014, the farm grows the LG variety Glory exclusively.

“Two years ago we tried a proportion of Glory as it meets all our criteria, being maturity class 10 and scoring 7.5 for early vigour, combined with high starch
content and excellent fibre digestibility,” Alan explains.  “It is the top ranked variety for starch yield and produces high dry matter yields.  It is 4^th highest on the BSPB/NIAB List for ME yield.”

The Glory was drilled on 15^th May which is about normal for the farm and harvested on 11^th October, being incorporated into the TMR from early November.

“The crop looked good for the year and was all ready to cut,” Kevin continues.  “The plant was a little green but the cobs were a good size and had ripened evenly.  It has analysed well (see table)”

Kevin focusses on making the best quality forage and minimising waste.  The maize clamp has concrete side walls and the forage was covered with an oxygen barrier and plastic sheeting.

To reduce aerobic spoilage the crop is treated with Ecocorn.  “I don’t think you need an additive to encourage more rapid maize fermentation, but we want to keep the face cool, especially in the summer.  There is no point investing in feed and then wasting it.  We have also reduced the face width to 32 feet to help reduce spoilage.

“By focussing on variety selection we can ensure we produce a high quality feed to act as the foundation of our feeding system right through the year but especially in the crucial early lactation period,” Kevin concludes.

Choon Farm LG Glory analysis 2015