AHDB Dairy showcased its latest research findings at the Discover, Innovate and Grow conference, Derbyshire. Laura Bowyer reports.
With the current milk crisis, high yielding dairy producers may be forced to rethink their feeding regimes, said David Keiley of SAC Consulting.
One method of reducing costs which some producers were turning to was zero-grazing, with grass being the cheapest feed available on-farm.
Mr Keiley said: “Our research was based on high yielding cows which are milked three times-a-day and shows there comes a point in these herds where it might be more economic to feed 50:50 grass and TMR rather than solely TMR. Our work suggests this point is 27-28ppl.”
Mr Keiley said there was mileage in zero-grazing for high yielding dairy cows and it stacked up better in a low milk price situation, with Mr Keiley suggesting the saving would be about 2-3ppl, providing better economies of scale in a herd of 200 cows plus.
Mr Keiley advised avoiding heating the crop, grass should not be ‘overly mashed’ when put through the wagon. He also advised against incorporating grass into the ration, but said to feed it separately.
He said otherwise it could jeopardise the integrity of grass, while increasing likelihood of rejection through ration heating.
It should be fed at the end of the day as a buffer, providing starch.
He said: “In our own consultancy, 3 per cent of clients have now adopted the zero-grazing system. We recommend grass is cut four times per day, providing meals of 15kg fresh weight per cow, with two cuts being taken in the morning and another two cuts in the afternoon.
“TMR should be put out first thing and grass should be cut from 11am onwards, as it will have a higher sugar content later in the day. Feeding grass in this manner requires a smaller grazing platform and enables a longer grazing season.”
Quality must be managed, and it was noted zero-grazing improved utilisation of grass, as cows were not excreting on pasture and no areas of the field were being missed, so the grazing platform did not have to be as big.
Another method of trying to stimulate dry matter intake was through cell grazing, said Mr Keiley. “Using this practice, 100 cows can be fed from one hectare per day, involving six fence shifts per day.
“This is a more intensive management method, with a shorter grazing season than zero-grazing, although zero-grazing can deal with 0.5ha per 100 cows at peak growing season, halving the area required.”
|Forage||Costs (including labour)|
|Fresh grass: including machinery hire purchase over 5 years, fuel and running costs.||£73/ tonne dry matter|
|Total mixed ration: including grass silage, maize whole-crop, blend, fat and minerals||£205/ tonne dry matter|
|TMR and fresh grass||£125/ tonne dry matter|
|Grazed grass||£65/tonne dry matter or £11/tonne fresh weight|
There has been a large amount of research into the link between bedding bacteria and udder health and, although there have been links established, they have not always been clear and consistent, said Andrew Bradley, specialist in cattle health and production.
However, it is considered bedding management factors are more important than bacterial numbers in bedding.
Mr Bradley was involved in a study into bedding management, not just bedding type.
Through management, teat contact and exposure could be minimised. Teat hygiene needed to be maximised in the parlour, while increasing the cow’s defence at the same time.
The trend in research of a sample of dairy herds of more than 300 cows showed recycled manure systems tended to have higher levels of bacteria per gram than sand and sawdust.
The bacterial count of sand sat in the middle of the data range, whereas sawdust bed bacteria counts were mixed, with some at the highest end of the scale and others at the bottom.
Mr Bradley said: “When looking at the bulk tank, less bacteria is found here in comparison to the bedding, and there is no clear correlation between bacteria counts of the two. The bulk tank should not be used as a measuring tool for udder health.”
According to the research, deep recycled manure solids – or green bedding – could lead to cleaner udders. He added higher bedding bacterial load was not necessarily associated with an increased risk of intramammary infection or clinical mastitis.
However, some bedding materials could be associated with a higher risk of certain types of environmental mastitis. More than one million bacteria per gram of bedding caused an increased risk of mastitis.
Mr Bradley said: “Fore-milking brings down total bacterial count in milk produced thereafter.
“Teat dipping brings down streptococcus counts in the bulk tank, while cluster disinfection is associated with lower thermophilic and psychrotrophic counts – bacteria which thrive in extreme hot or cold conditions.
“But, there has been no proven link between somatic cell count and bedding type.”
He also said internal teat sealants could decrease 75 per cent of infection in the dry period, suggesting 90 per cent of dry cow mastitis was caused by environmental factors.
Chemical positions of grass samples can significantly change from being cut in the field, finding their way through the postal service and being received by the lab, according to Andrew Dale, scientist at Agri-Food and Biosciences Institute, Northern Ireland.
Mr Dale urged sample takers to get harvested samples to a laboratory within 24 hours of harvesting, to minimise the risk of changes in the chemical composition, although an immediate analysis was only really achieved in the first five hours of being cut in the field.
Mr Dale said: “We carried out research to see how the nutrient value of grass changed under different conditions after harvesting.
“There was little effect on the forage if the sample had air excluded or air present.
“But chilling trapped the quality, regardless if it was being stored for 24 or 48 hours, overriding whether it was in air-present or air-excluded conditions.”
Research suggested storing grass under breathable conditions resulted in an increased deterioration of the sample compared to those stored in sealed bags, irrespective of whether air was present or excluded.
Samples needed to be collected and stored correctly to ensure accurate results and Mr Dale advised they should be stored in sealed bags wherever possible.
He said: “Real-time information and analysis is becoming increasingly important and locking in the nutrient value in your grass samples is one way of achieving this.”
To improve sample consistency, farmers were advised to cut grass for analysis with scissors or hand shears, rather than plucking it.