The modern-day space race

Increasing cow space is beneficial to milk production and behaviour of housed dairy cows while also improving cow comfort, a recent AHDB funded trial has found.

Jake Thompson, vet at LLM in Derbyshire and a researcher at the University of Nottingham, was involved in the trial which evaluated the impact of indoor living space on dairy cow production, reproduction, and behaviour.

Jake said: “99% of UK dairy cows will be housed at some point during the year, but some cows have double the amount of space as others.

“It is important to consider how we improve management when cows are indoors, and we lacked the evidence to quantify how extra space impacted them.”

‘Living space’, the additional non-lying space availability for dairy cows above that deemed to be a baseline requirement, can be easily calculated using simple building measurements. This will help reduce the ambiguity and uncertainty which currently accompanies discussions about ‘loafing areas’.

“Farmers are asked to provide loafing areas without appropriate guidance of what and how this will impact their cattle. For example, opinions differ on whether passageways should be considered loafing areas,” says Jake.

Large variation in space allowances

Current housing recommendations on loafing areas and total space per cow lack clarity and vary widely.

As part of his PhD studies, Jake measured the total space given in 50 dairy farms across GB and found it ranged from 5.4 m2 to 12.7 m2 per cow, with the average farm providing 8.3 m2.

These results helped form an AHDB-funded trial at the University of Nottingham to evaluate the impact of indoor living space on 150 cows from the high-yielding indoor herd.

A year-long randomised controlled trial was undertaken in a unique, purpose-built facility. This allowed precise measurement and novel configurations of the housed area.

Adult Holstein dairy cows were randomly allocated into a ‘high’ or a ‘commercial average’ living space group. The high-space group was given 6.5 m2 of living space within14 m2 per cow overall space, compared to the control group with 3 m2 living space within 9 m2 per cow total space.

Importantly, all other aspects of their environment, management, and husbandry were identical between groups. To ensure direct comparison between the two groups, cows were partnered by parity and days in milk, which meant that the group structure was also the same throughout the trial.

Jake said: “We wanted to measure the effect of living space against three main parameters: production, behaviour, and reproduction/fertility.”

Production was primarily measured using daily yield per cow. Rumination time, body weight, and milk solids data were also compared between groups.

To monitor behaviour, cows were fitted with their own wireless geo-location sensors, much like a ‘Fitbit’ for cows, which sent a location measurement every seven seconds. Comparisons were made between groups on the time spent in key designated areas such as living space, feed-face, and cubicles, as well as environmental enrichment use.

Time taken to pregnancy was used to measure the reproductive performance of the cows between the two groups. All key reproductive data such as artificial insemination records and pregnancy diagnosis records were collected. Underlying reproductive physiology was analysed using samples of Anti-Mullerian hormone (AMH) and milk progesterone levels.

Improved cow output

Cows in the high-living-space group gave similar peak yields to those in the control group but held their yield higher for longer through a lactation. This led to an increase in a 305-day yield from 14,644 litres to 14,746 litres, equating to over 100 litres per cow per 305-day lactation.

The largest yield effect was observed in the heifer population. Those in the high-space group produced, on average, over 600L per cow per lactation more than their control-space counterparts, increasing from 11,592L to 12,235L.

However, more space did not have such a positive impact on reproduction, with cows in the high-space group taking longer to conceive, although all other fertility parameters measured showed no difference between groups.

When these results were assessed in a simulation model, it indicated that the reduced reproductive performance was compensated for by the increased milk volume in the higher-space group. It is therefore still likely to be economically beneficial to provide more living space.

Increased space also provided enhanced cow welfare through significant behaviour changes.

“We found that cows in the higher-space group spent an extra 65 minutes/day lying down and an extra 10 minutes/day at the feed face. They spent less time in the additional living space and more time in the cubicles” says Jake.

This is the first long-term study to show that increased living space leads to meaningful benefits to milk production and behaviour of housed dairy cows.

Jake said: “Given the current large variation in space allowances provided to dairy cows across GB, the results of this trial should help farmers decide on how to invest in improving housing and ultimately improve cow comfort, wellbeing, and productivity.”