Watch: Three spring essentials to manage grass

Peter Hynes’ farm at Aherla, near Bandon in west Cork, is a farm in transition. Sixty cows were milked in 2014. One hundred cows were milked last year and 130 cows are calving down this year. The long-term goal is to milk 200 cows.

Five years ago, the farm was receiving a milk price 2c/litre below the Dairygold average. Last year, the average price received was 3c/l above the average. With the herd genetics more or less the same, Peter reckons it’s all down to better grass management.

The farm was chosen to host one of the 20 grass walks that Teagasc organised around the country. While acknowledging that Peter is fortunate to have a dry farm in a good grass-growing area, getting the most out of that grass takes planning and management.

The farm walk outlined the three essentials for managing grass this spring.

Spring rotation planner

The biggest obstacle to early spring grazing is the fear of running out of grass too early or, to be more specific, the fear of running out of land to graze too early.

Using the spring rotation planner removes this uncertainty as the planner allocates a fixed and increasing proportion of the farm for grazing during each week of the spring.

So by sticking to the area allocated by the plan every day, you can be certain that you will not have to start the second round of grazing earlier than you would like. Importantly, by sticking to the plan, you should have at least 30% of the farm grazed by the end of February, kick-starting this land into an aggressive growth phase and ensuring that there is sufficient grass for the second round of grazing in early April.

For Peter, the most important targets are to have 30% grazed by 28 February, 60% grazed by 13 March and all the farm grazed by 3 April, so the second round of grazing can start on 4 April.

“I’ll still be measuring grass weekly, so depending on the growth rates and farm covers, I will have some flexibility around the start date of the second round. If growth rates are good, I can start it a bit earlier and if growth rates are bad, I can put in some extra feed to delay it a bit,” Peter says.

By knowing what area is available to be grazed per day from the plan and by knowing what cover of grass is in that area and the number of cows to eat it, Peter will know how much extra feed, if any, needs to be fed. He doesn’t think he will need to feed any more than 3kg of meal per day or 180kg of meal per cow this spring.

Fertiliser

Peter was quick off the block and spread 23 units of urea/acre across 30% of the farm on 15 January. The following day, he spread slurry on another 30% of the farm. When asked if he was getting a response to this, he was certain that he was.

“The fields that got both the nitrogen and the slurry are definitely greener and growing faster than the other fields. I’m certain I’m getting a return from it and will be spreading the rest of the farm shortly.”

John Maher from Teagasc says that the response to nitrogen in spring is high, with 10kg of grass grown for every 1kg of nitrogen spread. The target is to have 60 to 70 units per acre out before 1 April, but 20 to 30 units per acre should be out in February, either in the form of bag nitrogen or slurry.

John says spreading 30 units per acre in February will be worth an extra seven or eight days of grass in the spring.

Grazing techniques

Pat Dillon from Moorepark spoke about the grazing techniques required to utilise grass in spring. He says having the right infrastructure is a big help – good roadway access and plenty of gaps into and out of the paddocks.

Peter went through his approach to grazing. He uses strip wires and temporary fences to allocate grass and walks cows in single file alongside a ditch or permanent fence to get them to the next section (see the video online for more on this).

When it is really wet, he will only go to the driest paddocks and the paddocks with the best access. He uses on/off grazing by letting them out for two three-hour grazing periods.

He says he makes sure that the cows are hungry when they are going out so they have a good appetite. He says he usually gives them a small bit of silage when letting them back in – more for his own peace of mind more than anything.

Questions from the crowd

Q. What should you do with high covers?

John Maher: Some fields with high grass covers are beginning to deteriorate. Just because they have a high cover now doesn’t mean they don’t need nitrogen, so I would say the best thing to do is to spread fertiliser on these fields and graze them in a few weeks when it will hopefully be drier and there will be enough cows calved to move through them faster.

Q. Is it not too early to spread nitrogen?

Pat Dillon: No, provided there is not very heavy rain in the 48 hours after spreading, the nitrogen will have worked its way into the soil and will be relatively stable and available for uptake. Soil temperatures are high at 6°C or 7°C, so it is essential that nitrogen is out as it will be used by the grass plant.

Q. Do cows need water at every grazing?

Peter Hynes: When I’m on-off grazing, the cows get water in the shed and in the collecting yard, so I’m not worried about giving them water in the field. When I’m not on-off grazing, I try to give them access to a water trough for at least one grazing out of two, but there is a big water trough in the collecting yard so this is never really a big issue.

Listen to an interview with Teagasc advisor Grainne Hurley in our podcast below: