Careful balancing of rations and analysing silage regularly this year will be vital for farmers to maximise milk output and cut feed costs after early silage results reveal some potential pitfalls.

Some 200 first cut silage samples taken by Mole Valley Feed Solutions (see table) from across the UK were less digestible, had higher fibre content, and had lower energy values (ME) than in previous years.

Rumen fermentation could also be restricted if rations are not balanced appropriately due to a reduced lactic acid to volatile fatty acid (VFA) ratio.

"Rations will have to be modified this year if silage analyses show a low lactic acid to VFA ratio as this affects rumen function. The ideal ratio is at least 4-5, but this year's result is only 2.73, last year being 4.43," said Robin Hawkey, the company's senior nutritionist.

However, despite the results, Dr Hawkey says dairy farmers have the potential to increase margins even with high feed costs, but it will rely on them getting the most from their silage and maximising feed efficiency.

He suggests including live yeast in the ration to help cows digest the higher fibre, lower D value silages reported this year so far.

"Testing silage monthly and adjusting rations accordingly will be important to maximise feed efficiency. Whilst results show lower energy, protein levels appear okay, meaning less supplementation of protein may be needed. This is a win for farmers' pockets and the environment."

He also advises farmers to test silage if they notice a drop in production or change in the cows as it could indicate a shift in the silage quality and using additives in later cuts to help improve overall fermentation.

"Additives help improve fermentation, enhance the preservation of nutrients from the fresh crop to the ensiled crop and reduce dry matter losses. Whilst they are traditionally used on earlier cuts, these first cuts may not be as milky as previous years because of the lower D and ME values, so farmers may be more dependant on these later cuts to help them through."

Additives can be regarded as an added cost, but Dr Hawkey believes they are worth the investment due to the increased value of silage in the clamp and the potential dependency on these later cuts.

"The economics of the current circumstances means where silages were worth historically £30/t in the clamp, they are now worth far more, possibly £50-60/t. An additive now costs about £1.40-1.50/t, so if that helps improve the silage fermentation and the feed out and reduce the losses, it's a no-brainer," he said.

Farmers should also be aware of the mycotoxin risk, which could quickly become a problem with many farmers opening their clamps early and high temperatures.

"Mycotoxins are produced by specific fungi or moulds and tend to be a problem in drier silages. If farmers don't move across the face fast enough, secondary fermentation and mould formation can pose a significant risk to cows. Mycotoxins are also a risk when there isn't adequate fermentation, leading to more unstable faces of those drier silages.

"Mycotoxin binders are very effective and work quickly and cost 7-8p a cow a day," he said.

Table 1 Early first cut silage samples

No of samples Dry Matter (%) Protein (%) D Value ME

(MJ kg DM) NDF

(%) pH Lactic Acid

(g/kg) VFA

(g/kg) LA:VFA Structural

Fibre Index

2022 200 31.88 14.4 70.4 11.26 47.1 4.15 72.2 26.7 2.71 189

2021 163 33 13 71.1 11.4 43.8 4.3 72.7 16.4 4.43 176.00

2019-2021 average 34.03 14.20 70.97 11.37 45.03 4.30 70.63 16.50 4.28 180.83