As the weather turned wet in early October, the 2020 maize harvest could be described as a tale of two halves.
Farmers growing early varieties which were ready by mid-September were able to make the most of the dry early autumn weather and harvested in good time.
In contrast, those who chose to grow less costly later maturing varieties found themselves struggling to bring maize in during the very wet weather which characterised most of October.
Tim Richmond, UK maize manager with LG, suggests farmers who invested in modern, early maturing varieties, which are high in starch and have improved cell wall digestibility (CWD) are now reaping the rewards.
He says: “This year has shown yet again that farmers who grow the right variety in the right place and harvest it at the right time will have maize silage in the clamp which has a high energy density.
“Modern, early maturing varieties, such as LG Resolute and LG Prospect, have high CWD, which is critical because more than half of the energy from a maize plant is contained in the leaf and the stem, so these varieties have the potential to provide a very high energy forage.
“Varieties with high CWD will produce a feed with higher digestible NDF, which is vital for rumen function.
“Furthermore, the high digestibility of the plant means the silage made from it will be more palatable, resulting in higher intakes.
“Timely harvesting of these varieties will have resulted in excellent yields of maize silage with a high energy value, providing more milk from forage.
As a result, farmers will now be able to reduce the amount of purchased feed they need to buy-in, thus driving down costs.
Conversely, crops harvested late will have yielded a less productive feed due to increased lignin content and a higher proportion of dead material.” Mr Richmond points to the LG Feed Manager app, which farmers can use to compare different maize varieties and which calculates the financial benefit of growing the new early varieties.
Figures are calculated in terms of potential milk output, assuming a milk price of 28ppl.
"Farmers who grow the right variety in the right place and harvest it at the right time will have maize silage in the clamp which has a high energy density"
He says: “LG Prospect and Resolute deliver an added benefit worth £600-£775/hectare compared to average varieties.
When compared to the worst varieties, this difference rises to £1,300/ha.
“There is an increase of 4 per cent CWD for LG Prospect and Resolute, resulting in an increase in energy value to 12ME, compared to 11ME for the poorest varieties.” Roy Eastlake, LAN UK technical support manager, agrees, highlighting that growers who were able to harvest maize early and who now have quality silage in the clamp with high starch and digestible neutral detergent fibre (NDF) levels.
He says: “This early harvested maize has analysed well, but those who had to delay harvesting have seen increased fibre content due to higher lignin levels and lower proportions of digestible NDF.
“Once the maize silage has been in the clamp for at least two weeks, it is important to have a sample analysed to evaluate the nutritional quality.
Most nutrition companies will offer this as a free service, but if farmers have to do this themselves due to Covid-19 restrictions, it is important to obtain a sample which is representative of the whole clamp.
“Take about 20 sub-samples from a few inches behind the clamp face, following a ‘W’ shape across the face to ensure all parts of the clamp are sampled.
This should be placed in a bucket, mixed up, then a representative sample taken and sent to the laboratory.” Yields of maize have been better than expected, according to Mr Eastlake, but as many farmers were unable to carry over any forage from last year, it is important they now calculate what they have available to feed to avoid any shortages later in the year.
“Planning ahead is vital to ensure cows have a consistent diet throughout.
Using the results of the analysis, a nutritionist can assess the quantity of starch and digestible NDF available and balance the diet accordingly.
“Where the crop was harvested late, lignin levels will be higher, so less straw needs to be added to the diet.
“Adding a rumen specific live yeast product, such as Lallemand’s Levucell SC, will improve fibre digestion by favourably improving the rumen pH.
“Checking the cows’ manure regularly is recommended because it will indicate how much fibre is passing undigested through the rumen.
It will also be possible to spot if maize grains have not been broken up by the processor and passing through intact.” Mr Eastlake emphasises the importance of minimising wastage of maize and the need to adopt best practice clamp management and feed protocols.
He says: “Now the maize is in the clamp and the farmer has paid to grow, cut and clamp it, it is vital to ensure as much of it is fed to the cows as possible.
Avoiding waste through spoilage is essential.
“Figures show farmers who are best at managing their maize silage minimise losses to just 4 per cent, whereas those at the other end of the spectrum will lose about 15 per cent due to aerobic spoilage and feed out losses.
For every 1,000 fresh weight tonnes of silage made, assuming a dry matter [DM] of 32 per cent, this will give 320t of DM.
The difference in quantities of wasted silage between farmers who are the best and worst at managing their clamps will be 32t DM.
Based on an average cost of maize silage of £100/t of DM, with poor management, farmers are wasting up to £3,200 of maize DM.” Mr Eastlake points to careful clamp face management and the importance of discarding any spoilt silage to avoid contamination to further reduce aerobic degradation.
Across the West Midlands, Ian Evans says his clients have had the best maize yields in 2020 compared to recent years.
This is despite a cold spell at the start of the season and yet another wet October this year.
He says: “The impressive yields are down to more farmers choosing the established, early maturing varieties, such as LG Glory, but also improved management of the maize crops.
“Farmers now recognise the importance of removing compaction, creating the right seedbed, sowing at the right time, appropriate weed control and feeding the maize plant with the correct and adequate nutrition.” Mr Evans recommends farmers grow a maize variety which is in maturity class eight or above.
He says: “This season we will also have the exciting new variety LG Saxon delivering up to 7 per cent higher fresh weight yield than current varieties; this should help growers maintain high maize yields.
Some farmers in Shropshire and Montgomeryshire drilled maize around the Easter Bank Holiday weekend, so completed their maize harvest before the end of September and did not encounter the very wet and difficult conditions later in October.
“We were frequently seeing yields as high as 50 fresh weight tonnes/hectare across our area, with DM averaging 30 per cent, but often as high as 32-35 per cent with starch at similar values.
“The earlier harvest dates this year have allowed many farmers to establish a wheat crop after maize, while others have drilled a Westerwolds ryegrass ley so they can protect soils over winter but also secure an early silage crop next spring.
This has both economic and environmental benefits.” Mr Evans says many farmers have had to open their maize clamps very early this year as clamps were empty at the end of summer.
Quality While this is not ideal as the maize does not get sufficient time to ferment, because some of his clients were using a bespoke maize inoculant, Mr Evans reports quality has not been compromised.
He says: “The specific bacteria in Lallemand’s Magniva Platinum Maize inoculant helps to significantly reduce aerobic spoilage organisms, such as yeast and moulds.
This has enabled farmers to open their maize clamps in as little as 15 days without adversely affecting the aerobic stability of the silage.
Farmers have commented that their maize has remained cool and it is feeding really well.
“Feedback has been very positive and I have been able to respond to farmers’ enquiries confirming the presence of this bacteria in the grass and wholecrop innoculants.”
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