Waikato DairyNZ Farmwatch for week ending October 20

While pre-graze mowing can be used as a tactical tool, research suggests post-graze topping may be a better option.

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By DairyNZ

As pasture levels lift, farmers will be considering strategies to maintain quality going into summer.

Pre-graze mowing is a management strategy sometimes used to achieve target pasture residuals when there is a pasture surplus.

Results from a trial conducted at Lincoln University Research Farm confirmed previous research that, compared with good spring pasture management:

1. There was no benefit of pre-graze mowing on cow intake, milk solids production or cow condition with both mown and grazed farmlets producing 1.8 kg MS/cow/day throughout the experiment

2. There was no difference in cow behaviour (lying, grazing, or ruminating times) between farmlets

3. Pasture performance was reduced in the mown farmlets. Pastures were less dense (kg DM/ha) for a given height, contained less tillers and had reduced growth rates

4. Less silage was conserved from the mown farmlets, but more silage needed to be fed to maintain cow intakes

Farmwatch graphic / DairyNZ

While pre-graze mowing can be used as a tactical tool, research suggests post-graze topping may be a better option. Cows can select higher quality feed, as smaller leaves (e.g. clover, new tillers) don’t fall below the grazing horizon. It is easier to identify a surplus if cows graze pastures first. See more at Pre-graze mowing - DairyNZ