Farm Ireland

Tuesday 12 December 2017

Risky grass management strategies can pay off now in creating a surplus


Mary Kinston

The thing I love about grassland management is determining the present situation, weighing up the best plan of action for the week ahead and then Mother Nature playing a blinder that results in it being the right decision.

For example, just over a fortnight ago, I measured our farm and the decision was either to run the farm with a demand of 65kg DM/ha and a pasture cover of 753kg DM/ha (180kg DM/LU) with a slight surplus evident above the target line on the feed wedge, or tighten things up to a high demand of 77kg DM/ha/day (pasture cover 742kg DM/ha (155kg DM/LU).

Often farmers do their grass walk, look at the feed wedge and decide it's better to be conservative about their grass covers, than overestimate or risk a feed deficit, saying to themselves, 'I'd rather be looking at grass than looking for it'. Many would, in this instance, have taken the conservative option and ran the farm with a small surplus and, at a pasture demand of 65kg DM/ha for another week, see what happened and go from here. However, knowing the farm and that it had provided sufficient grass growth to provide for a demand of 75-85kg DM/ha/day since the end of April, and also that surpluses perpetuate surpluses, it prompted my decision to step up the pressure and push demand back up to 77kg DM/ha/day.


The weekly farm walk, the weather for the week ahead and knowing the farm's ability is critical to making a sound decision. In this case, everything was sweet one week later and the cover had actually increased to 817kg DM/ha. In addition, it provided the opportunity to clean up the odd paddock where seed heads were appearing and reducing pasture quality. Working on such a knife-edge of grass supply and demand can make the weekly farm walk rather addictive.

As we all know, Mother Nature doesn't always like to play in our favour, so was the decision potentially reckless and likely to cost money in supplement due to a pasture deficit? Everybody hates a feed deficit, and I believe this is because it's easy to put a monetary figure on it in terms of the cost of the extra ration or silage required to fill it and because we hate to think we are compromising the cow in terms of intake and production potential.

However, at this time of year, the decisions required to manage a deficit are easier than those of a surplus and often small deficits are ridden out by hanging tough, getting the fertiliser out and letting growth catch up or exceed demand.

Perpetual surpluses have the biggest cost, due to a loss of pasture quality that penalises the cow's diet and her ability to produce. Often, milk yield and milk protein will fall drastically in July as a result of letting a surplus fester. There is also a larger cost of corrective management -- either in the form of extra cutting for bales, topping or pre-moving as a small surplus in a few paddocks often manifests into a surplus over the whole farm. Therefore, this month and the start of the next still present an opportunity to be optimistic and manage for quality before quantity.

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However once we hit mid-August, it's time to switch from optimism to conservatism by extending the rotation and building pasture covers for the autumn, which will allow you to milk on with less supplementary feed.

Another key decision at the moment is the date to end mating, by either finishing AI or pulling the bulls out from the heifers and milking cows. Opting for a 12-week mating period is the first step to developing a compact-calving pattern. A normal pregnancy is 40 weeks, so conception must occur within 12 weeks of calving if a cow is to calve on or before the same day next year. A longer mating period will reduce the number of empty cows but it also results in a higher percentage of late-calving cows, which will drag out the calving spread for the next year and so on.

In the past, there has often been a market for late-calving cows, but will this market exist next year when there is a lot of pressure on our quota position?

Rather than letting your AI straws run out or allowing the bulls to hang around the cows or heifers, take action and choose whether you will either eliminate the late-calving cow or continue to allow her time to go in-calf. If you decide to wait for her, what will you do with her?

Mary Kinston is a farm consultant based in Kerry. Email:

Indo Farming