INTRODUCING American genetics means some UK Jersey herds are averaging more than 6500 litres at 5% butterfat and 4% protein. But recognising that lack of nutritional knowledge could prevent the breed from maximising its potential, one Oxon producer is seeking solutions from CEDAR, at Reading University.
Making do with rationing programmes designed for black-and-whites, which do not take account of the Jerseys high output potential compared with her size, is frustrating for producer Duncan Dawes.
"No one knows how the Jersey works. Computer rationing programmes are based on research done on black-and-whites. Considering the Jersey as a small black-and-white means feeding ends up being hit and miss," he explains.
His 200-cow summer calving herd, run with his wife Felicity, at the 92ha (230 acre) Poplars Farm, Hornton, Banbury, averages 6500 litres at 5.4% fat and 3.9% protein. Average concentrate use is 1600kg for the cows which are housed from calving through to April. Mr Dawes believes feeding inside is the only way to maximise their potential.
Nutritionist, Clive Harris explains that the rations for Mr Dawess Jerseys are formulated using data obtained from black-and-white cows, modified to take account of smaller body size and increased milk solids content.
"We have looked at how some top US herds are fed. But they benefit from alfalfa silage and dried alfalfa which have a higher intake potential than grass silage," says Mr Harris.
Short grazing season
Total mixed rations and short grazing seasons are the norm for US Jersey herds visited by Mr Dawes.
"In the US it is all TMR. There is some loafing and grazing but this tends to be for a maximum of two and a half months a year," says Mr Dawes.
"The top yielding Jersey herd in America achieves 12,000 litres. Up to now most milk has been sold on liquid contracts, but the situation is changing and they are starting to look at fat and protein."
Recognising the lack of nutritional data relevant to Jerseys a year ago, Mr Harris and Mr Dawes discussed the problem with CEDAR director David Beever, from the agricultural department at Reading University, who is keen to conduct research. A project starting this autumn will study Jersey metabolism and how results can be applied to a practical situation, explains Mr Harris. "Partitioning of energy to milk or body fat, dry matter intakes and digestion of different forages including grass, forage maize and legumes will be studied.
"It is possible that Jerseys store more fat internally than black-and-whites, which may be mobilised more efficiently."
Mr Dawes has expended considerable effort in securing animals for the project. "There is a lot of variation within the Jersey breed. We wanted to include smaller Channel Island types and larger American types, so we will be sourcing cows from each extreme for the research," says Mr Dawes.
But getting producers to part with animals for research has been difficult, he admits. "Asking producers to donate their top animals temporarily for the work at CEDAR did concern some but I explained that cows would be in good hands and under regular veterinary supervision.
"We have secured animals from eight herds with a variety of calving dates so that we are covered for when research begins."
The project has attracted attention at home and in the US, gaining support of breed groups, semen companies and feed companies. "This work is for the good of the breed and we have a massive amount to learn," he adds. *