Reduce waste to mitigate milk-price squeeze (Jan 26)

Feed is too valuable to waste, particularly this winter. So we shares some pointers on how to maintain forage and feed quality and maximise intakes.

TEXT PHIL EADES

Focusing on reducing feed waste will underpin margins and preserve feed stocks at a time when milk prices are under pressure.

“Recent movements in milk pricing have come at the worst time possible for milk producers,” says Trouw Nutrition GB’s Alicia Wilson. “Producers are faced with having to juggle the pressure of tight margins with, in many cases, low forage stocks. So with feed being the most significant cost when it comes to  milk production, ensuring the diet is used as efficiently as possible will be crucial.”

She adds that dairy diets will have to be carefully formulated, monitored closely and amended as required to ensure optimum yields and feed efficiency to maximise available margins. “And one area where producers should keenly focus is on reducing feed spoilage and waste, which can increase feed costs.”

The root cause of feed spoilage is the activity of micro-organisms, particularly yeasts, on silage once it is exposed to the air. “The microbes feed off energy in the diet, reducing the energy available to the cow,” explains Mrs Wilson. “Spoilage can compromise diet freshness and palatability, reducing dry matter intakes of the entire TMR and not just the forage element. And the presence of active yeasts and moulds increases the risk of problems with mycotoxins.”

In the presence of oxygen, dormant yeasts are activated and immediately start to affect feed quality. They degrade lactic acid, producing heat and water. As the pH of the silage increases moulds, fungi and bacteria further degrade the silage, rapidly fermenting sugars, proteins and starches into CO2 and heat.

Increased rejections

“Unless the problem is addressed, the micro-organisms will continue to proliferate further degrading the silages but also other ingredients in the TMR,” adds Mrs Wilson. “After mixing and feedout, the longer feed remains in the trough the greater the degradation in available energy and the bigger the risk of reduced dry matter intakes, which leads to increased rejections.”

She stresses that the loss of energy can significantly impact milk yields. Increased microbial activity decreases sugar levels in silages by 10% or more, which reduces the ME content by 0.25MJ/kgDM.

If a cow is consuming 10kgDM of silage per day, this is equivalent to a reduction in energy intakes of 2.5MJ/day, equating to 0.5 litres of lost milk per cow. “At 40ppl, this is a loss of 20p per cow from daily margins. But the impact on dry matter intakes can be more significant,” says Mrs Wilson.

“Cows are selective eaters with a particularly strong sense of smell. They will reject diets that have heated and have reduced palatability,” she adds. “They will sort diets more, spend longer periods at the trough and less time lying down and, ultimately, more feed will be left in the trough.”

Tidy face: good clamp management is key to reducing waste

Typical TMR

Looking at a typical TMR, formulated for maintenance plus 55 litres and based on 50:50 maize and grass silages and 6kg of a blend, if cows ate the target amounts they would consume 46kg freshweight and 18.05kgDM per day. At current prices the diet would cost £3.43 per cow per day.

“An extremely conservative 2% reduction in daily dry matter intakes, which is not unusual if diets are affected by spoilage, would reduce intakes by 0.38kgDM per cow and result in the loss of 0.8 litres per cow per day,” explains Mrs Wilson. “Margins would be reduced by 32p per cow and 1kg of diet freshweight would be wasted.”

For a 180-cow herd these losses would add up to 4,320 fewer litres produced per month, a £1,382 reduction in margin, and 5,400kg of feed wasted that puts even greater pressure on tight forage stocks.

“If the dry matter loss was combined with the reduction in energy content due to microbial activity, then yields could be reduced by 1.3 litres, further increasing the margin that would be lost,” says Mrs Wilson. “And it is probable that herd fertility would also be impacted.”

She adds that it will be important to watch for signs that spoilage is a problem because it is possible to reduce its impact by taking preventative action. “Check the silage clamp regularly and look for signs of spoilage on the face, top and shoulders. But also remember that micro-organisms can be active without physical signs of spoilage. Signs of spoilage include white, green or black spots, as well as clumping or discolouration.”

Producers should also monitor waste levels in the trough. “If cows are leaving more than they would usual this is a sign of rejection,” she says. “Watch cow behaviour – are they sorting the diet more or spending more time standing at the trough and not eating. Inspect the rejected feed to see if it is heating up or has a sour and musty smell.”

It is the presence of oxygen in the clamp that initiates the spoilage cascade. “So maintain a tight face to help prevent spoilage, moving across it quickly,” adds Mrs Wilson. “Ensure block cutter knives are sharp and only uncover the clamp in small increments.

“Remove and discard any spoilt material to reduce the extent of spoilage and avoid further contamination of clean feed. Also be sure to keep troughs clean, removing rejected feed to prevent contamination when new feed is added.”

Microbial load

As spoilage causing organisms are always present on all forages, she says it will pay to take steps to maintain a low microbial load on the forage to reduce the fermentation activity. Selko TMR is a blend of buffered organic acids and acid salts that’s optimised to create a hostile environment for micro-organisms, effectively reducing their growth and activity in the TMR.

The blend of acids inhibits microbial growth by penetrating microbial cell membranes, disrupting their structure and function, ultimately inhibiting microbial growth. This results in less heating, improving palatability of the ration and reducing dry matter and nutrient value losses.

The product can be added to the diet in the mixer wagon or sprayed onto the silage face. In trials it has been shown to maintain feed intakes and milk yields.

In one trial, where cow behaviour was observed, cows fed a diet treated with Selko TMR exhibited faster eating, fewer visits to the feed trough and less time in total at the feed trough. Cows fed an untreated diet were slower, more selective eaters and spent more time at the trough and less time lying down and ruminating. Cows on the treated diet produced 0.9kg more milk and had greater feed efficiency.

Mrs Wilson stresses that the presence of spoilage organisms increases the risk of mycotoxin poisoning. If mycotoxins are suspected, she advises screening clamps and using Selko Toxo to bind and eliminate the toxins.

“Reducing feed waste is one practical step that producers can take this winter to help mitigate the impact of pressure on margins and make best use of forage stocks,” she adds.