You know that your silage quality and feedability directly impacts the amount of feed you need to buy in. Getting the cut timing and fermentation right will maximise protein, digestible fibre and dry matter retention, reduce spoilage and shrinkage and increase digestibility to boost milk production from your forage.
To get the best quality silage, it’s helpful to think of all forages as arable crops, even the grass, with a clear agronomic plan tailored to maximise the growth and quality of the crop. This way you will set the forage up for a successful growth phase. Before making silage, pre-cut testing will also help you keep track of grass quality. Aim to be ready to start mowing two weeks prior to the “normal” cutting date for the farm and go during the best weather window in those two weeks if the quality is there. It’s not about making 4+ cuts, it’s about the digestibility of the grass at cutting. Every 5-unit increase in D-value produces approx. 40,000 litres of additional milk from the same 1,000t of 30% DM silage.
Treating your grass silage with an inoculant is also proven to help retain valuable protein and enhance digestible fibre in silage. There are naturally occurring microbes that break down protein in their metabolism, producing foul-smelling silage acids, leading to nutrient loss and reduced silage palatability. These microbes can be inhibited quickly if you use a proven, specific forage inoculant to rapidly drop the pH below the level where they can be active.
Other important points to consider alongside the inoculant if you want to maximise the amount of protein retained in your grass silage:
- Do not wilt grass for more than 24 hours. Studies have shown that up to 20% of the initial protein will be broken down when grass is wilted for >24 hours.
- Only mow the amount of grass that can be picked up before rain, because wet grass has a higher rate of protein breakdown than dry grass.
- Spread slurry far enough in advance (minimum 4 weeks) so no residue is left on the leaf surface, because slurry is rich in microbes that break down protein.
If you want to maximise the digestibility of your forage consider the maturity of the grass when you cut it. Only two of the three fibre types are digestible in the rumen and as the grass matures the proportion of the indigestible type of fibre increases making the forage inherently less digestible before it is ensiled. A common measure of fibre is called neutral detergent fibre (NDF), and it should be between 38-40% for the grass to be at the optimal digestibility.