Shinagh open day to offer pointers in effective grass use
Shinagh dairy is a joint investment by the west Cork co-ops in developing a 200-cow spring calving herd on a 77ha farm that demonstrates best practice. It is operated in conjunction with Teagasc and there are 196 cows, 40 replacement heifers and 55 heifer calves on the farm.
Not all the ground is available for grazing because of reseeding. We have 74.67ha available now. This gives us a stocking rate at present of 3.22LU/ha. We estimate that the heifers are eating 15kg/DM/day (not as much as mature cows at 17-18kg/day). Our grass demand is now 48kg DM/ha. We had a lot of reseeding done earlier this year and this is now part of the grazing ground. Growth rates each week are high on this ground, usually double what the permanent pasture paddocks are producing. Last week, our growth over the whole farm was 64kg DM/ha/day. We usually walk the farm once a week but will walk it even more regularly during periods of high growth to estimate a grass cover on each paddock. We produce a grass wedge based on these covers and this, combined with our cover per cow, helps us in making management decisions.
We have been going into covers of around 1,300kg/ha all season. We try to graze out each paddock well every time. Our target grazing residual was 4cm earlier in the season and is now increased slightly to 4.5cm. We measure this residual with a plate meter. In measuring this, we take a random walk through the paddock after grazing and drop the plate every 10 steps.
This method ensures that we measure both grazed ground and around dungs. At the intensity that we are aiming for in our grazing, all grass around dungs is clipped by the cows and between dungs is grazed to the floor. The objective is to produce a lot of high-quality grass on the farm and then to have high utilisation of this grass by grazing it at the right stage and leaving a low residual after each grazing.
We don't get it right all the time, but we have a target we are trying to achieve. Like any farm, grass will exceed demand at times of the year. We take these paddocks out for bales and try and target the paddocks that we did not get grazed as well as we would have liked at some stage. Cutting allows us to start with a clean sheet in that paddock once again. We are happy with our contractor, who is cutting paddocks for us as low as the cows graze.
We are starting to build up grass now for the autumn. We are doing this by letting the paddocks go to higher covers and not cutting them for bales. We have enough nitrogen left in our derogation plan allowance to apply more. This will go out in the next week when there is a better response to nitrogen than in September. All season, we were running at an 18-20-day rotation and a grass cover of around 130kg DM/cow. We are now at a grass cover of 225kg DM/cow and pushing the rotation out to 28 days. We want to get to a rotation of 42 days by the end of next month and a grass cover of 1,100kg DM/ha.
We don't want to cut anymore paddocks for bales from now on. But, if we feel we are going to exceed this cover, we may have to. We do not want the cows having to graze covers over 2,200kg/ha in October, and this roughly equals a farm cover of 1,100kg/ha.
Shinagh Open Day