Farm Ireland

Thursday 27 October 2016

Dairy: Cut your costs this spring by switching to on-off grazing

John Donworth

Published 17/02/2016 | 02:30

Ideally cows will be put out to grass in spring.
Ideally cows will be put out to grass in spring.

As a nation, we are fascinated by the weather, particularly rainfall.

  • Go To

Personally, I have an interest in measuring how much of it falls every 24 hours and as I was writing this piece, my rain gauge was telling me that 72mm had fallen in the first 10 days of February where I live close to Limerick city.

However, my colleagues in Killarney were able to tell me that down there, 130mm had fallen over the same period.

Every dairy farmer out there knows that it is going to be a tough spring as regards milk price. March is traditionally the lowest milk price month of the year as solids are at their lowest levels, particularly milk protein percentage.

The spring is the most expensive time of the year on dairy farms and every effort needs to be made to keep costs under control.

Ideally, this means getting cows out to grass and replacing expensive silage with cheap grass.

This is easier said than done, but the technology is tried and tested and it works. Increasing the number of days at grass should be an objective for every dairy farmer. This is particularly so in the spring. So, can we take the cows natural grazing cycle and turn it to our own advantage?

When cows are out for 24 hours, they only graze for about nine or 10 hours. The rest of the time they are either loafing around, lying down and chewing the cud or just enjoying the day so cows don't have to be out for 24 hours to be fully fed.

However, if you want to let them out and maximise their grass intake, you must do it at two specific times in the day.

These two times are after both milkings. The cow has a natural inclination to graze aggressively after each milking. This period lasts for about three hours.

It is up to you, the farmer, to exploit this 'window'. To get the cow ready for the first time for on/off grazing, she needs to be out of silage by 5am in the morning if they are going to grass by 8am.

If cows are going to grass at 8am, by 11am they will have grazed for 96pc of the allocated time. These cows are not hanging about. Once they go out, their only focus is on grazing grass. In fact, these cows are so focused on grazing, they will increase their bite rate per minute from 26 grams of grass to 37.6 grams of grass - a 30pc increase in biting rate. That's not the end of the story.

The amount of grass they take in each bite also increases. Again the figure is 30pc. All the while the cow is compensating for her reduced access to pasture.

So, if you are offering 8kgs of grass dry matter in a three-hour allocation, she will have 90pc of that removed in three hours. At the end of the period, the cow goes back to the cubicle shed, only to come out again for another three hours. after evening milking.


Should you alter the time you milk your cows in the evening? Yes is the answer. Ideally, the evening milking would be between 3.30 and 4.30pm.

Then the latest the cows are back into the house for the night is 7.30pm. Should the cows have access to silage at night? The answer is no. Silage is a bulky feed. It produces gut fill and this will depress the appetite for the cow when she goes to grass the following morning at 8am.

Emer Kennedy in Teagasc, Moorepark has carried out experiments over two springs in Moorepark to validate this on/off grazing technology. It works. Cows were also fed 3kgs of concentrates while on the 31-day trial period.

Minimising group damage is one of the major benefits of on/off grazing.

Poaching/treading results in reduced grass growth as leaf is buried, plants are crushed and one also has a reduction in shoot and plant growth. In a bad situation, this can be in the order of 50pc.

John Donworth is Teagasc Regional Manager for Kerry/Limerick

Indo Farming