By Teagasc’s Seán Cummins and James Fitzgerald
Much of Ireland has been gripped in storm-like conditions over the past number of days, bringing copious amounts of rainfall and posing challenges when it comes to grazing on heavier farms.
On account of the higher than average rainfall over the month of August in many regions, grass dry matter levels are falling to 12% and below and, as a result, the live weight gain ‘power’ of grazed grass is beginning to diminish significantly – especially for spring-born, dairy-beef calves.
Although many farmers would have traditionally waited until early/mid September to reintroduce concentrate feeds to calves – given the levels of precipitation we’ve witnessed – meal feeding should be fast tracked to spring-born calves to avoid any blip in daily live weight gains prior to housing.
Asking calves to meet their energy requirements from grazed grass only when grass dry matter levels drop to 12% is too big of an ask.
[grass_growth_map from=”2020/08/18″ to=”2020/08/25″]
The below table indicates the kilograms of fresh weight grass a 190kg calf requires on a daily basis at various dry matter levels.
The quantity of fresh grass the calf must consume increases by just over 10kg/day once dry matter grass levels fall from 18% back down to 12%.
In practical terms, this means the calf will have to consume 50% more fresh weight grass each day to just meet their dry matter intake needs when grass dry matters fall from 18% to 12%.
With the falling grass dry matter levels being witnessed at farm level, calves must be supplemented with a good-quality, fibre-rich concentrate at a rate of at least 1kg/day to ensure average daily live weight gain targets of 0.7-0.8kg/day are protected between now and housing.
The question is often raised on whether or not the economics of meal feeding dairy-beef calves at grass during the months prior to housing are justified.
The simple answer is that if this level of intervention can achieve a daily live weight gain of 0.2kg/day over and above what can be achieved from low dry matter grass diets only, it is cost neutral at slaughter time down to a received beef price of 280c/kg.
- Growth: 76kg DM/ha/day;
- Demand: 25kg DM/ha/day;
- Average farm cover: 1,312kg DM/ha/day;
- Stocking rate: 2.52LU/ha.
Grass is continuing to grow despite only 13 units/ac of nitrogen being applied since July 1 and a growth rate of 76kg DM/ha was recorded over the past week.
Some of the paddocks have a high clover content and this has kicked in and helped growth over the last number of weeks. I plan on spreading 27 units/ac of CAN next week and that should finish the year for us in terms of fertiliser.
The average farm cover is running at 1,300kg DM/ha or 521/LU currently, which is a little bit high. I had intended on cutting some of the paddocks for bales, but weather conditions just didn’t allow.
The calves on this block are entering covers of 2,000kg DM/ha, but they are cleaning them out well and the grass is clean and leafy. The way they are grazing these covers, it looks like we won’t be cutting silage once the weather improves.
I reintroduced meal to the calves on Monday and they are being supplemented with 1-1.5kg/day of a home-mixed ration. I also have four of the worst performing paddocks on the home block sprayed off for reseeding.
- Growth: 37kg DM/ha/day;
- Demand: 31kg DM/ha/day;
- Average farm cover: 1,114kg DM/ha/day;
- Stocking rate: 2.04LU/ha.
The amount of grass on the farm is coming close to the highest it will be for the year at 1,114kg DM/ha. From now on with shorter days – and most likely colder weather – grass growth is going to slow down by quite a lot.
Gradually, the cattle will eat their way through this grass up to when the most of them will be housed in late October.
Some of the finishing bulls have been housed already and are currently getting 5kg of meal along with some of the bales taken off the grazing ground earlier in the year.
The true worth of these bales is clear from the fact that I was feeding closer to 8kg of meal to last year’s bulls when the silage wasn’t as good. I will keep an eye on how the bulls are doing and step up the meal a bit more if needs be.
I have 8ac sprayed off for reseeding and I am waiting for a couple of fine days together to till and seed it. The grass mix that is going in is ‘Goldbite’ by Drummonds which is a good mix for taking an early cut of silage and grazing for the rest of the year.
I will close up this ground for first cut for the next couple of years and reduce the amount of second cut taken so that silage quality might be increased overall.
The reseed ground as well as some of the grazing ground beside it is after getting 1.5 t/ac of lime. Hopefully, that will set up that block of ground to grow better and more grass over the next few years.