It is two years since the University of Nottingham’s 240-cow herd moved into the £6million Centre for Dairy Excellence. Jonathan Wheeler finds out what impact the new facility has already had.
Giving dairy cows adequate space can improve both milk yields and cow health, experience from the University of Nottingham’s new dairy research unit suggests.
Much of the last two years have been spent collecting data from the herd that will form the baseline for future studies. Some benefits were quickly apparent.
The then 240 cow herd moved in May 2018 and saw yields swiftly rise from 10,500 litres/cow to around 12,500 litres/cow.
In itself that was a surprise, says the University’s Professor Phil Garnsworthy. “Often you would expect to take a hit on milk production for a couple of months when you move a herd. But milk yields increased from the day the cattle went into the new unit”.
Those gains have been maintained, and improved on, even though the closed herd includes many heifers as it expands from 240 head to its eventual target of 360. It contains 325 cows now.
Currently yields are stable at 12,700 litres/head, coming from a total mixed ration containing three forages, and concentrates fed at milking.
The forage element of the ration contains equal thirds – on a dry matter basis - of grass silage, maize silage and whole-crop wheat.
The concentrate element is based on soya and rapeseed meal, protected fats, combined with minerals and molasses.
The TMR is fed at 47kg/day. Additional concentrates are fed via the milking robots at 0.45kg/litre to animals yielding over 30 litres/day.
Somatic cell counts hover around 100, well down on the 174 it was before the herd moved into the new accommodation, with mastitis incidence also much reduced.
The extra space each cow gets in the 7,500 square metre development is noticeable throughout, but most pronounced in three areas – around the milking robots, at the feed stations and drinking troughs, and in much larger ‘loafing spaces’.
Even when the herd reaches its 360 cow target the new unit leaves them with 10 per cent more cubicles than the need so all cows can lie down at once.
This means they have space for extra walkways between blocks of cubicles. This reduces the influence of ‘bully cows’ and is helping younger animals and heifers gain better access to feed and water, improving both their performance and that of the whole herd.
Prof Garnsworthy says: “The full amount of space provided in the unit is about 1.5 times the recommended level (14.2m2 v 8.75m2).
“All animals can eat at individual feeding stations, which are at wider spacings than normal. We find cows eat more at them than if they are competing for feed in a trough.
“If you have a real bully animal, she can clear all the other cows away from a silage face or a trough and stop anyone else from eating.
“One of the design aspects of the new unit is the numerous cross over points between the cubicles, so if there is a dominant cow the other animals can avoid it”.
The design has also led to gains in cleanliness and associated disease reduction.
Prof Garnsworthy says the sand bedded cubicles have not only increased lying times but have also helped to reduce incidences of mastitis.
Robotic muck scrapers are also used on the slatted floors.
Prof Garnsworthy explains: “The scraper system in the older building used to push the slurry the full length of the building.
“When it ran, any cows standing in the passageway got a bow wave of slurry on their hooves and legs – and potentially onto their udders – several times a day, so they were continually wet.
“The better level of cleanliness is a major benefit to cattle health. Dry, clean feet has reduced lameness and the most serious mastitis threats now are mainly environmental”.
The herd expansion means they have a very high proportion of heifers at the moment, and as a result heifer management has been crucial.
Prof Garnsworthy says: “We are looking for well-grown heifers that meet their target weight for age, because they last longer and produce much greater life-time milk yields.
“Heifers that eat better in their first lactation will also perform better as they are still growing at that stage, and if they cannot get enough food they either do not grow as well, or they reduce milk yield”.
In this respect reducing the influence of ‘bully cows’ is a major benefit.
The drop in mastitis issues and better fertility management are playing role in these improvements and staff expect to be able to make further conclusions from the wealth of measurements now being collected in the unit. Prof Garnsworthy says: “We do notice that cows seem to be showing oestrus better and holding to service more reliably. Butterfat levels have also improved even while the cows have been producing better yields.
“We have not changed the diet, but cows are eating a lot more forage than before and digesting it better”.
That more efficient production is being realized in better environmental performance. “Milk production is about 20 per cent greater but methane emissions have remained about the same, so the emissions per litre of milk produced is lower, and the maintenance portion of the emissions is spread over a much greater volume of milk", adds Prof Garnsworthy.