GARY, Ros and Justin Zweck, Blyth, South Australia, heard about grape marc as a feed supplement and were interested in its potential for their dairy herd’s feeding strategy.
Grape marc is a by-product of winemaking with a high concentration of fat and tannins.
Crimped marc is steam-distilled grape marc that has been screened to remove stalks then rolled to crush the seeds, improving digestibility and energy availability.
Crimped marc is basically a silage material with 50 per cent moisture and with modest but consistent values of 12-13pc protein, 8-9pc fat and a metabolisable energy score of 11.
In early 2015 the Zwecks took part in a trial of crimped marc held byTarac Technologies, with results showing an increase in average milk production and no discernible difference in fat and protein.
Gary continues to incorporate crimped marc into his feeding strategy because it is a good replacement for cereal hay or silage and, at $200 a tonne DM for cereals and $95/t DM landed for the crimped marc, there is a significant cost saving to the ration.
The difference in moisture content between the crimped marc and cereal silage it is replacing means the crimped marc provides more dry matter with less water.
Some other high-fat supplements have been found to suppress feed intake and milk production so this feature of crimped marc is a positive for its inclusion in the ration.
Production volumes when feeding crimped marc are good, but Gary has found they need to work hard to manage the fat content of the milk, and with their payment structure this is important.
The Zwecks work with their nutritionist to make sure the ration keeps the milk’s fat content as high as possible.
Another note of caution is that the crimped marc can heat up in storage and mould can be an issue if stored for long periods of time.
Gary buys a load a fortnight so it doesn’t need to be stored for long.
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