Dairy farmers who add straw to their cows’ diet would be better off taking up yachting, says a rumen specialist.
Lincoln University expert Jim Gibbs spoke to about 100 farmers at DairyNZ’s FeedRight roadshow at the Westpac Taranaki Agricultural Research Station (WTARS) at Hawera last week.
Gibbs said adding straw to a pasture-based diet was a waste of money. Not one study showed an increase in milk production when straw was added.
“You’re replacing something that has an ME (metabolisable energy) of 12 with one that has an ME of 6 or 8. You’ll see either a loss of production or no change.
“You should take up yachting rather than feed straw. The effect on the cows will be the same and you’ll enjoy yourself a whole lot more.”
WTARS was the last of 22 stops for the nationwide roadshow, which covered a range of topics about dairy cow nutrition. Sixty people also attended the roadshow in Inglewood.
A panel consisting of Gibbs, DairyNZ scientist Jane Kay and Canterbury consultant Terry Hughes answered questions about dairy cow nutrition.
Gibbs said the roadshows were held because it was difficult for farmers to obtain independent, unbiased information about feeding cattle. Much of the information available to New Zealand farmers was based on overseas research based on dairy cattle kept in stalls and fed grain.
The amount of water consumed by cows on a pasture-based diet was much higher than that of stall-fed cattle. He described a New Zealand dairy cow’s rumen as full of 140kg of “wet lawn clippings” rolling around. Her daily intake of about 18kg of quality pasture and about 100 litres of water created a greater water flow through her rumen than through the rumen of grain-fed cattle. The rumen of a pasture-fed animal represented 20 to 25 per cent of its liveweight, twice that of a grain-fed animal.
Kay said reports that high levels of urea in milk were harmful to cow health were false.
“The big thing is that urea is not toxic, it’s not detrimental to the cow.”
Research had shown high levels of urea in milk had no impact on cows’ reproductive performance. Levels fluctuated because they reflected protein in the diet. If the level was above 30 decilitres, extra protein was probably not needed. If it was lower than 15 decilitres extra, protein might be needed.
Kay advised farmers to buy on cents per megajoule of ME. A supplement revenue predictor on DairyNZ’s website outlined profit to farmers from feed they purchased. She said a high-starch feed like maize silage should be introduced slowly in a pasture-based system.
Source: NZ News
