The focus on the Teagasc Green Acres Calf to Beef Programme farms has switched to silage harvesting, with the aim of having all first cuts completed by May 24.
While the majority of farmers enrolled in the programme have grass saved either in the form of first-cut pit silage or surplus bales, one farmer in particular, Martin Connolly – who farms in Castleplunket, Co. Roscommon – has made a significant improvement in terms of silage harvest date and quality.
The scale of the operation has increased in recent times with the expanding national dairy herd and some 120 Friesian bull calves are purchased each year, with the intention of bringing these through to beef at the end of the second winter.
While Martin – who works as an agricultural contractor off-farm – always made strides to cut silage mid-May, over the past two years, silage ground was grazed late into spring which resulted in fertiliser being applied too late and pushing out the closing date.
As it turns out, with the silage date pushed out until late June, the weather went against Martin in both 2018 and 2019, resulting in poorer-quality silage for his dairy calf-to beef operation.
Silage sample results at the back end of 2019 indicated a dry matter digestibility (DMD) value of 63.1% and 61.8% for first and second-cut silage respectively.
So, while there may be room for lower-quality silage on suckler farms, that is not the case on calf-to-beef units. The quality and cost of the winter diet fed to all stock in this system is extremely important in ensuring that liveweight targets are met and that physical and financial farm targets are achieved.
Calf-to-beef systems require high-quality silage of 72-74% DMD, which is a key factor in achieving the desired levels of animal performance and reducing feed costs over the winter months.
When silage quality falls to a sub-optimal level, increased levels of concentrate supplementation are required in order to achieve the targeted average daily gains for weanlings and finishing cattle.
The expense of this increased meal feeding is a significant cost to the system and it has the potential to erode a significant proportion of the margin achievable per animal.
Despite 2018 and 2019 not going to plan, Martin is well on track to harvest top-quality silage this year. Firstly, Martin and his dedicated programme advisor, James Fitzgerald, completed a silage budget for the farm earlier in the year.
Following this, slurry was then applied in late March – to ground grazed tight in the backend of 2019 and earmarked for silage – before following with nitrogen (N) fertiliser and closing up in early April.
This 42ac block includes 14ac of newly-reseeded land, which was sown in early August, 2019, and a 3ac paddock which had gone too strong for grazing and was subsequently taken out of the rotation.
With favourable weather conditions forecast for this week, Martin opted to knock the grass with a 10ft mower on Monday evening / Tuesday morning. This was then allowed to wilt before these swarths were raked on Wednesday.
On Thursday, the silage was lifted with a wagon and the pit was rolled and covered by that evening.
Commenting on the harvest, Martin said: “I got caught in June on both occasions over the past two years and we ended up running a couple of weeks over, so the quality wasn’t there.
“I’ve made the conscious effort to get it early this year and the weather has thankfully come good for us. We’re lucky this year.”
There is a significant link between earlier harvesting dates and increased silage quality. A rapid reduction in silage quality is seen in crops harvested from late May onwards, as the plant enters into its reproductive phase.
Silage quality deteriorates significantly after this growth stage, with a 0.5% drop in the DMD value expected each day thereafter.
Therefore, just like Martin has achieved, the optimum time to cut first-cut silage from a bulk, quality and expected harvesting conditions point of view is mid-May.
“Normally, we swarth the grass with the mower, but we just felt if we left it for the day and then raked it would be a better job. It was quite heavy even though it was dry and the run with the rake did a great job yesterday,” Martin explained.
Wilting is very beneficial for preservation where sugars are marginal and/or nitrates remain elevated. The aim should be to increase crop dry matter to 27-30%. This is best achieved by tedding out rows and wilting for 24 hours in good conditions.
Data from Teagasc Grange shows that grass left in larger rows (+3m) will not dry sufficiently to be effective. In addition, anaerobic conditions are essential for initial fermentation and to prevent subsequent spoilage.
At the pit, Martin rolled the grass with the loading shovel to remove any pockets of air that may be present, before covering with heavy duty covers. Ideally, farmers should cover with two 125mm polythene sheets and ensure that there is no damage to allow anaerobic conditions remain.
A silage analysis will be completed later in the year to evaluate the quality of the silage present in the pit, so concentrate feeding rates can be identified.