Cultured yeast gives yields a rise

There's a lot of untapped potential in cows after years of keeping a lid on production costs, reckons Lancashire dairy farmer David Talbot. He's now using a cultured yeast feed supplement developed in the USA which has lifted daily cow yields by 1.2kg for a cost of about 8.5p a day.

Yeast products are not a new concept, but Lactaid - the yeast being used in Mr Talbot's 180-cow herd at Lower Alston Farm, Ribchester, Preston - is a cultured yeast rather than a live yeast.

USA ruminant specialist Tom Lorenzen, who has been touring the UK, says 75% of US dairy herds are now using stabilised yeast cultures. About 20% of the UK's dairy herds use a yeast supplement, but most herds are using live yeast.

"The problem with live yeasts is their instability," says Mr Lorenzen. "The rumen is an unfavourable environment for live yeasts and doesn't enable them to produce the necessary metabolites.

"These are all essential for feeding rumen bacteria and for rapidly increasing the total number of fibre-digesting bacteria to help to stabilise the rumen."

Cows in Mr Talbot's Riblee Holstein herd, which has an average yield of 8600kg, were failing to hold body condition after calving and it's a problem that was affecting overall herd health and leading to a higher level of returns to first service.

"Like many dairy farmers, the genetic potential of our herd has been steadily increasing over recent years and they've been milking harder. Holding body condition on cows has become more difficult.

"We started using the cultured yeast in January and saw an immediate lift in yield and a steady improvement in cow condition, overall health and better fertility," says Mr Talbot.

The yeast supplement, which is fed to high yielders for about 20 weeks, was temporarily stopped when cows were turned out to grass this summer.

Mr Talbot, who expects his herd average to reach 9000kg by next year, believes the cultured yeast has also reduced incidences of acidosis and boosted feed intakes. Cows, which are housed and fed at night even in the grazing season, are fed about 50kg of a TMR mix each day.

The mix comprises maize and grass silage, brewers' grains, a balancer meal and chopped straw to give an 18.5% protein mix. Concentrates are fed in the parlour up to 9kg a head.

Figures produced by Agri-Lloyd, which is marketing Lactaid in the UK, show the extra milk produced is valued at 32.64p a cow a day based on a current milk price of 27.2p/litre. The net additional income - taking account of a 9.5p a day yeast cost - is 23.14p. The cumulative benefit is worth an extra £4665.

The experience in this herd is in line with the benefits seen in the USA, says Mr Lorenzen. "There's been enhanced feed palatability, improved yield and increased dry matter intakes in this herd while the cultured yeast is maintaining a higher rumen pH to stimulate rumen microbes.

"In developing this cultured yeast supplement we've taken the guesswork out of feeding yeast to cows. Because live yeast can't survive in the temperature of the rumen, it's not performing an effective function.

"A cultured yeast is providing metabolates and that's what improves digestion and forms the basis for healthier, more productive cows."

The recommended feed rate is 50g a cow based on a 10,000-litre yield and although Mr Talbot's overall yield improvement this year is two litres a cow - partly due to a change in concentrates - the manufacturers believe many herds have the potential to lift yields by up to 2.5 litres a day simply by incorporating cultured yeast.

"The low milk price in the UK, as in the USA, has been holding producers back, but during this period there hasn't been a slow down in genetic progress. Far from it. There's a vast amount of latent production potential in UK dairy herds and as milk returns improve I believe we'll see many producers begin to fully exploit the real income earning ability of cows," reckons Mr Lorenzen.

Yeast supplement

• Up to 2.5 litres a cow increase
• Survives rumen heat
• Feeds rumen bacteria