All farmers participating in the Dairylink Ireland programme have an electronic weigh bridge to track replacement heifer growth and help hit the main liveweight targets.
Everyone can judge weights by eye to a certain extent, but it is surprising how far out estimates can be.
We visited Nigel Corbett’s farm last week. Going on current weights judged by eye, I would have been certain that his main batch of replacement heifers averaged more than 207kg when last weighed in mid-May.
The range of weights within a group is a key factor that makes it difficult to accurately estimate a group’s average weight by visual assessment.
As most dairy farmers don’t have weigh bridges, a weigh band tape is a much cheaper option which gives fairly accurate estimates of weights.
Cost saving
Having an up-to-date list of weights allows heifers to be regrouped and fed accordingly. As well as pushing lighter heifers on, it can result in a saving with concentrates cut back or removed completely for heavier heifers.
The main targets are 60% of mature weight at breeding and 90% of mature weight at calving at 24 months of age.
The latest figures from CAFRE indicate that the average heifer-rearing cost in business development groups in NI is £1,766 (€2,006) and the average age of first calving is 28.3 months.
With AFBI researchers estimating that it costs £2.87/head (€3.26/head) for every day a heifer calves over 24 months of age, this helps explain the wide range in heifer-rearing costs in groups from £1,438 (€1,634) for the top 25% of farms to £2,167 (€2,462) for the bottom 25%.
Banbridge, Co Down
There are 27 in-calf heifers due to calve down in autumn. We sold off eight heifers in spring as maiden heifers because we didn’t need them to maintain cow numbers and they would have been calving down too late, as we are moving towards a single autumn-calving block.
There were also five heifer calves sold off around the same time for the same reason. At present, we have 34 heifer calves in two groups. The stronger group was weighed in mid-May and 23 averaged 207kg. They are getting concentrates at 2kg/head/day and need to grow at 0.75kg/day to hit our 360kg liveweight target for breeding at the start of December.
The other group of 11 are lighter calves from later-calving cows. We are considering selling some more calves, as some of this group will not hit 360kg liveweight at the start of December. Another option is to serve them later and sell the surplus heifers for a better price as spring-calving in-calf heifers.
The first cows are due to be dried off at the start of July and will start calving in September. Yields are holding up well, with the herd averaging 27.6 litres at present. Concentrate feeding is continuing to fall back, with average feed rate of the 16% crude protein nut at 4.5kg/cow/day.
Reseed
We reseeded a six-acre field on the grazing platform in mid-May and the grass seed initially struck well and came out of the ground. However, we have had no rain since before it was planted and the dry conditions are putting some stress on the new grass.
We were considering irrigating the paddock with a slurry tanker, but it shouldn’t be needed now with rain forecast for this week. A mixture of the late-heading tetraploid AberGain and diploid AberChoice was used in the paddock and it was drilled in one direction.
First-cut silage was cut on 18 May and was clamped in good condition. It was a good-quality crop and there was as much or maybe even more bulk than last year’s first cut. Regrowth for second-cut was coming along well, but it has slowed up recently with the dry weather.
On the grazing platform, we were reluctant to take some heavier covers out for silage over the past few weeks as growth had slowed up. This meant some of these paddocks were not cleaned out well and residual targets were missed. We started topping some paddocks after cows last week and will continue to top when needed to maintain quality in swards.
On Monday, we decided to mow down three paddocks of heavier covers with this being the first surplus grass baled this year. Cows were then moved on to lighter covers and clean-outs are a lot better now.
Infrastructure
Work is continuing with improving grazing infrastructure on the farm. New drinkers were purchased last winter and are being installed. Additional drinkers will give us more flexibility when dividing paddocks and allocating grass to cows.
New hardcore laneways were laid at the end of last year and we put a layer of fine-binding quarry aggregate on top of the surface this week. The material still might be a bit sharp, so we are considering a layer of quarry dust on top of it as well.
The new laneways will give better access to paddocks and will allow more flexibility when grazing areas of the block that are mostly cut for silage, particularly in spring and autumn. Away from the grazing platform, we have done some fencing work on the outfarm to allow better grazing management of heifers.