A bale of grass with higher density has multiple advantages. Fewer bales are needed to store the same amount of crop, which reduces the costs for transport, storage and film. But the greatest advantage is higher forage quality.
Round bales with a 10% higher density – a calculation example
A farmer has to bale 1000 tons of grass a year with an average dry matter percentage of 40%. With an average bale weight of 650 kg, the total is 1539 bales a year. If the baler is set to a higher baling pressure, the bale density increases. So, if the bale density is 10% higher on average, what is the result?
Baseline calculation example:
|Amount of grass per year
|Average dry matter content
|Average bale weight
|Number of bales
10 % higher density:
|Average bale weight
|Number of bales
In the example above, a 10% higher bale density adds up to 140 fewer bales per year for the same volume of silage. And there’s no need to use any film for those 140 bales. With film costing €99 for a roll of 1500 metres, the cost to wrap 6 layers of film is €4.501. Film binding costs €1.27 per bale2. The total cost for film is €5.77 per bale. This delivers a total saving on film costs of €808 per year. Using less film also lowers the environmental impact.
Savings on film costs:
|Wrapping 6 layers of film3
|Binding 3 layers of film4
|The total cost for film per bale is
And, additionally, there are 140 fewer bales that need to be transported from the field to the yard and you save storage space for 140 bales. This gives a total annual saving of € 526 on transport and storage costs.
Savings on transport and storage costs:
|Transport costs per bale5
|Storage costs per bale6
|Total transport and storage costs per bale
Less air, more and better forage
10% more grass in the bale replaces air, which results in less oxygen in the bale. Less oxygen in the bale is beneficial for a fast and effective preservation process. Some amount of energy and dry matter is always lost in the bale because sugars are converted into water and CO2 by bacteria that need oxygen. The less oxygen there is in the bale, the faster this process will stop so more dry matter and energy will be retained in the silage. A higher bale density also benefits good shape retention as the bale is less likely to collapse. If a bale collapses, the layers of wrapping can slip apart and allow oxygen to enter the bales between the film layers. This will restart the decomposition process leading to losses of dry matter and energy.
At least 2% loss of dry matter
2% less of dry matter thanks to a higher bale density is a realistic assumption according to Sjon de Leeuw of agricultural consultancy PPP-Agro. In practice, the difference may even be much higher. In the example of 1000 tons of grass a year with a dry matter content of 40%, the total amount of dry matter is 400 tons. A 2% loss means 8000 kg more dry matter retention per year. At an average cost of €0.16 per kg of dry matter, this converts to a saving of €1,280 per year. The costs of producing the grass, such as fertilising, mowing and baling, have already been made. If additional forage has to be bought, then the costs of the dry matter losses are even higher.
Savings through better preservation:
|Total dry matter per year
|Lower dry matter loss in %
|Lower dry matter loss in kg
|Forage costs per kg of dry matter7
The greatest benefits are to be found in terms of agronomy. Better forage quality improves bale palatability which leads to a higher feed intake by the cows. Optimal preservation also reduces mould in the bales and lowers the health risks. This in turn lowers the costs for veterinary care. Higher quality forage makes it easier to maintain good milk production levels in dairy cattle.
Fewer other ingredients have to be added to the feed to compensate, so it is easier to formulate a balanced ration. A good bale equals ‘homegrown concentrate’.
Slightly more fuel may be needed to create a higher bale density, and there will be more wear and tear on the machine. But, in the majority of cases the advantages will outweigh these disadvantages.
Summary of benefits
Financial benefits (calculation example):
Savings on film costs : €808
Savings on transport and storage costs : €526
Lower dry matter loss : €1,280
Total annual savings : €2,614
- Better forage palatability à higher feed intake
- Less mould in the bale à lower health risks à lower costs veterinary care
- Possibly easier to maintain milk production levels due to better forage quality
- A better bale a ‘homegrown concentrate’