Harvesting high quality silage is vital for farms that will be milking cows in the shed next winter, and now is the time to place a focus on this.

The quality of silage or forage can have a significant impact on the cost of production during the housed period or on farms where cows are fed using a total mixed ration (TMR).

Lorna MacPherson, a dairy expert with SAC Consulting, says now is the time to look ahead to managing this year’s silage quality to reduce input costs as well as the farm’s environmental footprint.

MacPherson is part of the Farming for a Better Climate initiative run by SAC Consulting – part of Scotland’s Rural College (SRUC).

SRUC uses on-farm trials and industry expertise to help farmers across Scotland to introduce pragmatic and cost-effective measures to reduce the environmental impact of their enterprises, as well as improving profit.


Commenting on the importance of harvesting high quality silage, McPherson said: “With feed costs still relatively high this year, it makes sense to maximise the potential of homegrown forage, which is the cheapest and often largest part of the ration.

“This is a good time of year to decide how you will manage your silage.

“By making some small, considered changes, you can reduce bought-in concentrates and fertiliser but produce the same or more milk through higher quality silage, you offset both costs and related emissions.”

Lorna MacPherson, a dairy expert with SAC consulting
Image: SAC consulting

Silage cut and harvested earlier will have an improved digestibility and energy value.

MacPherson noted that while overall yield will be lower with earlier cutting, it is a good option for those who currently have ample forage stocks or cereals to wholecrop.

She also recommend that farmers know the nutrient value and indexes or their soil and slurry.

She said: “Silage cut even a week earlier can improve the digestibility (D-value) by 3.5% points and increase the energy.

“An uplift of around 0.5 megajoules (MJ)/kg of dry matter (DM) can increase the milk yield by one litre/cow/day (assuming a 12kg DM intake from silage).

“In addition, raising crude protein in silage from 13% to 14% would save 0.4kg of rapeseed meal.

“This could see an overall saving of 72kg concentrate/cow over a six-month period for the same level of milk output.”

MacPherson said that reducing bought-in feeds, including soya, helps reduce the farm’s carbon footprint, and focusing on nutrient management to maximise soil health and productivity locks carbon into the farm to help offset emissions, as well as improving grass yields and helping to extend the grazing season.


MacPherson advises that farmers get their slurry test prior applying on silage fields, as chemical fertiliser levels could be reduced.

“By getting the slurry also analysed, you can adapt slurry applications appropriately and save unnecessary spend on buying in artificial inputs.

“For early cut silage, adding sulphur, which is not naturally available in the soil at this time of year, can boost yields by 10-15%, as well as its nitrogen use efficiency (NUE) which will improve the protein level.”

Continuing, MacPherson said: “We’ve seen through the trials we’ve run with the project’s Climate Change Focus Farms that making changes to reduce the farm’s environmental impact usually positively correlates with improving financial gains for the business.

“In the case of improving silage quality, this directly translates to economic benefits for farmers, as it enhances animal nutrition, reduces feed costs and increases productivity.

“In turn, increasing production efficiency by producing more milk from fewer and more targeted inputs will lead to less emissions per kilo of milk output.”

Longer-term factors for achieving good silage quality include ensuring good drainage and reducing compaction, and considering newer grass varieties which will benefit grass crop quality without compromising yield.

Improvements in feeding management, along with better fertility, genetics and herd health, can also play a part in improving both profit margins and environmental efficiencies.