With rising purchased feed prices, forage quality is going to be a major objective on dairy farms this winter. Farmers are advised to look closely at all aspects of quality when selecting maize varieties this year.
Tim Richmond, Maize Manager with Limagrain UK, maintains that while maturity class must still be the primary selection criterion, it is then vital to focus on varieties delivering the highest quality forage to ensure maize supplies the maximum benefit in terms of reducing feed costs and improving margins. He says new varieties are capable of delivering higher quality feeds.
He says: “A recent survey showed by selecting varieties based on experience, sticking with what they have grown before, a significant proportion of farmers are missing out on the huge advances that have been made in plant breeding, particularly in terms of the quality of the feed produced.
“In the last 24 years, the milk production potential of maize varieties has increased from 30,900 litres/ha to 44,800 litres. That is an increase of 45 per cent and demonstrates why farmers need to commit to new varieties rather than sticking with varieties that might have been successful in the past.We have seen advances in yield, feed quality and agronomy, which combined mean new varieties can give a better return on investment.
“A new variety on the BSPS/NIAB Descriptive List can supply sufficient energy to produce about 600 litres more per hectare compared to the average variety. This equates to a concentrate feed saving of about £65/ha.”
For a farm growing 30ha of maize, he says this would cut the purchased feed bill by £1,950 with no increase in growing costs compared to an average variety. With feed costs on the rise, the financial benefit of selecting varieties shown to support higher milk production will only increase.
While maize is still seen foremost as a starch producing crop, he says it is important to look at the total energy the crop can provide as this drives not only energy yield but also how well cows will perform on the forage.
“You need to look at the whole plant as you do not just harvest and feed the cob. Up to 50 per cent of the total energy available is in the leaf, stover and other vegetative material, so it makes sense to maximise the contribution they can make to the feed in the clamp. As cows are fibre-digesters, improving the utilisation of the fibrous parts of the plant can bring benefits in terms of rumen health and diet formulation and this is where the Limagrain breeding programme has been focussed for more than 30 years.
“The cob is 92-100 per cent digestible so there is little opportunity to influence energy yield. However, the rest of the plant is 40-70 per cent digestible, meaning if cell wall digestibility (CWD) can be improved so the energy available will increase. The only way to significantly increase energy production per hectare now is by improving CWD, and improving CWD does more than just increase energy content and yield.”
He says research by Professor Mike Wilkinson from the Maize Growers Association shows each 1 per cent increase in fibre digestibility will raise total dry matter intakes by 0.12kg/day. This compares well with American research which showed each 1 per cent rise in CWD increased total dry matter intake by 0.17kg/day, resulting in a yield increase of 0.25 litres per cow per day.”
“So not only does improving CWD increase the usable energy in the plant, it also encourages higher forage intakes giving a two pronged benefit when looking to control purchased feed costs.”
By selecting varieties with a good balance of starch and CWD, he says farmers will optimise forage quality and production from forage and reduce purchased feed requirements.
“Farmers should look closely at starch content, CWD and energy yield when refining their variety choice, as there is a significant difference in milk yield per hectare between average and top varieties ranked on energy yield. CWD in particular is going to become increasingly influential in variety selection.”