2 August 2002

More cash in cubicles?

High straw prices and rising

somatic cell counts have

forced some producers to

consider switching from

yards to cubicles. But is it

cost-effective?

Richard Allison reports

CONVERTING loose straw yards into cubicle housing has boosted the financial performance of one Somerset herd by 3p/litre, due to improved cow performance and lower bedding costs.

More than nine years ago, Neil Christensen decided to rip out cubicles and house cows in straw yards. "Cows had outgrown cubicles and lameness was becoming a big problem because cows couldnt lay down comfortably.

"Good housing is particularly important at Steanbow Farm with 450 cows housed for nearly eight months of the year to make way for the annual Glastonbury Festival held on grazing land."

He believes it was the right decision to move to straw yards with cows averaging 6000 litres. But with cow yields increasing to more than 8000 litres, straw use was becoming excessive at 4t a cow each winter. Cow numbers were also declining as the space allowance increased from 4 to 5.5sq m a cow (45 to 60sq ft a cow).

"We were also struggling to keep somatic cell counts under control, averaging up to 300,000/ml. This was despite having one member of staff totally dedicated to bedding yards twice daily and cleaning out buildings monthly.

"Spreading manure on rented land 5-6 miles away was also a large cost, with several tractors clocking up 100 miles in a single day transporting muck."

The trigger for change was the need to bring the unit back into profitability, says Promar national dairy consultant Derek Gardner. "Straw yards were proving costly and one solution to cut costs was to install cubicles designed for larger cows," he says.

Mr Gardner is convinced of the importance of cow comfort. "Some herds in the US achieve 15,000 litres a year, but you dont obtain these high yields from feed alone. Other factors, such as housing, are equally important."

One option considered was cow mattresses, but they have a high initial cost of £50 a place. In addition, mattresses in the UK are different to those in the US, which are 20cm (8in) thick with shreds of tyres. Mattresses in the UK are thinner and tyre shreds tend to be pelleted making mattresses harder.

"We selected sand cubicles as they passed the comfort test. If you can drop on your knees without any pain, the bed is comfortable for cows," says Mr Christensen.

He constructed cubicles with a 30cm (12in) wide concrete kerb at the rear. Tyres were laid on their side in the bottom to prevent cows digging out sand. These were then covered with a 15cm (6in) layer of sand. This meant the step was higher than recommended at 20cm (8in) high, but no problems have been observed.

Having a kerb helps minimise maintenance as most dung falls on the kerb, which is scraped off before cows return after each milking, he says.

Cubicle dimensions were a compromise, as they were being installed in an existing building. We settled for narrow scraping passages and cubicles 2.3m (7ft 6in) long and 1.1m (3ft 9in) wide. Making beds too small is a sin, believes Mr Christensen.

"Double rows of cubicles were installed without a brisket board, with the ends left open to provide lunging room. There are no uprights to bruise pin bones."

After installing cubicles, there was an immediate increase in daily milk yield of 1.5 litres a cow. Mr Gardner believes this is due to improved cow comfort, as cows seemed to lie down more. "Blood flow to the udder is 30% higher when cows are lying down, increasing the supply of nutrients for milk fat synthesis."

Within the first year, there were also improvements in somatic cell count, with the herd qualifying for a milk quality bonus, says Mr Christensen. "This milk quality bonus alone has paid for the cubicles within a single year."

Cow fertility has also improved, with conception rates to first service at 49%, compared with 32% when housing in straw yards three years ago. But he admits this may not be entirely due to adopting cubicles.

"One benefit of better cow fertility is an 11 day reduction in calving interval to 388 days. Over the same period, average milk yields have increased from 7800 litres to 9400 litres."

Greater cow comfort also means lameness is no longer a problem, which together with improvements in fertility has cut replacement rates. "We had the luxury of culling 36 cows on milk yield for the first time this spring.

Mr Gardner believes switching to sand cubicles at Steanbow Farm has reduced bedding costs by 2p/litre of milk. "Sand costs about £30/year for each cow when using 2t/cow, more than five times lower than straw at £160/cow.

"Combining these lower costs with increased value of milk sales and lower labour requirements, the overall benefit is nearly 3p/litre."

But there is one downside when using sand, with greater wear and tear of slurry equipment, says Mr Christensen. Ideally, dung should be scraped directly into a lagoon. However, the unit has underground channels, which can become blocked with sand.

Contractors currently apply slurry with umbilical injection three to four times a year, but this may change in future and the unit may be forced to buy its own equipment, he adds. &#42

"We were struggling to control somatic cell counts, despite having one member of staff dedicated to bedding straw yards twice a day," says Neil Christensen.

Improved cow comfort led to a 1.5 litre a day increase in milk yields, says Derek Gardner.

&#8226 Lower bedding cost.

&#8226 Reduce somatic cell count.

&#8226 Cow comfort critical.