The Irish Agriculture and Food Development Authority (Teagasc) – pronounced Chogis – has carried out extensive research on pasture-based dairying systems at its Moorepark research centre in CountyCork. As part of that it’s also investigated various wintering systems, their costs and the impacts on animal health and welfare factors, the subsequent season’s milk production and reproductive performance.
Its scientists have found that ultimately cost will have the main bearing on which wintering system is best. Their research shows there are no animal welfare or production benefits to putting a roof over a wintering system.
But that’s not to say there aren’t other benefits such as reducing the frequency of cleaning of the standoff pad or the ability to reduce slurry storage requirements in higher rainfall areas.
Welfare benefits
Some differences were found in animal health indices such as lameness depending how clean the standoff pads were kept and body condition score (BCS) gain was never better indoors compared with cows outdoors on pads.
Calves from cows wintered in outdoor environments were found to be born heavier than those from mothers housed indoors.
The studies did conclude there was better potential for higher cow welfare standards with outdoor wintering than indoors in cubicles.
Cows could exhibit more natural behaviour in outdoor systems, the research found.
Teagasc dairy enterprise leader and head of livestock systems research at Moorepark, Padraig French described one set of experiments carried out over two winters from 2004 to 2006 looking at alternative wintering systems to the traditional housed, cubicle bed sheds.
Cow trials on a wintering pad in Ireland where the effect of a roof and shelter was investigated on standoff pads.
“We were looking at alternatives that would bring down costs,” he said.
“We wanted to lower capital costs, get improved labour efficiency and reduce running costs but at the same time make sure the systems were environmentally secure and didn’t affect animal performance.”
Four wintering systems were investigated with one – the housed cubicle system – used as the control. The other three were:
- An uncovered woodchip standoff pad with an adjacent concrete apron where cows were fed silage at a barrier.
- A covered woodchip standoff pad, which had two sides sheltered with windcloth and a polythene tunnel roof. Cows were fed silage at a barrier on a concrete apron next to the standoff pad.
- A woodchip standoff pad with a silage bunker on top where cows could self-feed.
In the first winter the self-feed pad system wasn’t included as an option and the stocking density on the covered feed pad area was higher than the uncovered pad.
In the second year the stocking densities on the outdoor systems were the same.
In year one there was no effect on daily milk yield or composition but in year two cows on the self-feed pad and unsheltered pad produced more milk than the cubicle cows.
During year two there was also no effect on BCS or liveweight but there had been in year one with indoor cows having BCS higher than uncovered cows. The milksolids (MS) yields are for the first 250 days of lactation and were all first lactation animals.
The scientists found the higher feed intakes of cows on the self-feed system suggested differences in reproductive performance and milk production may have also been related to feeding system rather than just wintering system.
Cows on the self-feed pad that had continuous access to food performed better, suggesting that outdoor systems that could facilitate a self-feeding regime and be kept clean had the potential to improve productivity. Self-feeding on a scraped, designated feed-pad area adjacent to a standoff pad could be the best option.
French said a comprehensive study of cows’ climatic energy demand found that while outdoor cows had higher energy demand than those indoors they could still produce twice as much heat as the climate stripped off them.
They were never in energy deficit, suggesting that keeping cows warm is not a reason to house them over winter or put a roof over their head.
Hoof health
In year one cows housed in cubicles had higher sole bruise scores at calving than those wintering outdoors.
Cows on the outdoor wintering pads had better foot health at calving but sole bruising increased rapidly once they came off the pad and went out to grazing pastures, particularly those on the unsheltered pad. The Irish scientists believed this was because the wet and muddy conditions on the pad softened the hooves, predisposing them to bruising once they had to walk to milking twice-a-day (TAD).
In year two they found cows on the sheltered pad and in cubicles had harder hooves than those on the uncovered outdoor pads. They also found animals on the uncovered standoff pad with the self-feed stack on top of the pad had the highest heel erosion scores and a higher digital dermatitis score at calving because they were standing in muddier conditions with more cow effluent.
They concluded the optimum pad design for hoof health was one that included a concrete apron that’s cleaned or scraped several times a day.
Animal behaviour
In the first year of their studies scientists found cows on the unsheltered pad had higher standing and idling times but they believed this could have been addressed by more frequent cleaning off of the woodchip pad through the winter.
The behavioural indices they used to measure how “happy” and comfortable cows were in year two indicated they felt more comfortable on the outdoor pads and could exhibit more natural behaviour.
Outdoor cows had long lying bouts indicating a highly acceptable lying surface.
Udder health, cleanliness
In the first year cows on the sheltered pad were much dirtier than those on all the other wintering systems but the stocking density was higher with cows given six square metres (m2)/cow compared with 12m2/cow on the unsheltered pads. In the second year the area was increased to be the same as the others and it was then the self-feed cows on the outdoor pad that were the dirtiest.
The level of animal cleanliness is largely determined by the frequency of pad cleaning with unsheltered and self-feed pads needing more cleaning than the covered pad.
Despite the uncovered systems having dirtier cows and the self-feed pad having higher levels of bacteria there was no significant effect on udder health or mastitis incidence of the different systems.
Scientists concluded that outdoor wintering systems could be managed so that milk quality and udder health was not compromised.
