3 August 2001

CROSSBREDSBACKONSONG

Crossbred dairy cows taboo

appears to be on the wane

in the UK as milk producers

begin to follow the

New Zealand trend.

Jeremy Hunt reports

BRITISH dairy farmers have always had hang-ups about crossbred cows, but their views are beginning to change.

A big swing to crossing Holstein cows with Jersey sires is already underway in UK herds, with demand for semen reaching record levels.

The latest results from a testing programme in New Zealand show that this could increase UK cow longevity with crossbred dairy cows lasting two lactations longer than purebred Holsteins.

Herefordshire based Livestock Improvement – importers of New Zealand Jersey semen – say sales now account for 40% of their total turnover, with 98% of this Jersey semen used on Holstein cows.

"Many producers have decided to use nothing but New Zealand Jersey semen on their black-and-white cows.

"They have become disillusioned with the Holstein, particularly when faced with the need to produce milk more cheaply than in the past," says the companys sales manager Colin Jones.

Crossbreeding is in vogue in New Zealand following concern among milk producers over the falling fertility and longevity of purebred Holsteins.

The latest results from a testing programme started in 1994 show that the average length of lactation of dairy cows in New Zealand is 4.5, across all breeds.

"But they show that for import-bred Holsteins average length of production is -119 days on the 4.5 lactation all breed average. The average for the New Zealand Friesian is plus 275 days. But when you compare the import-bred Holstein with the Jersey x Holstein there is 622 days difference in the average lifetime, that is two lactations.

"This is an enormous difference. Apart from the extra production there is a huge saving on replacements," says Mr Jones.

Official New Zealand Dairy Board figures show that the countrys highest yielding cows are crossbred fourth calvers. There are almost 700,000 Jersey x Holstein dairy cows in New Zealand in a cow population of 3.5m.

The crossbreds benefit from 5% hybrid vigour, which is equivalent to four years of genetic improvement in one generation, says Mr Jones. First-cross heifers are typically mated back to New Zealand Friesians.

New Zealand Jerseys are also capable of yielding up to 8000 litres, while still maintaining high milk solids.

"We all know there has been a historical reluctance by UK producers to milk crossbred cows. But those who have visited New Zealand and seen what these animals are capable of are convinced they have a vital role to play here and are beginning their own crossbreeding schemes."

With an average UK dairy cow lasting 3.1 lactations, Mr Jones says it is equivalent to having to replace the entire herd every three years. "If producers thought of it in that way, they would start to look at things differently."

A fertility index for New Zealand dairy cows has just been introduced based on 10m milk records. With 95% of the countrys dairy herds calving in the spring, bulls have been evaluated on their daughters calving dates.

The figures show that bulls with the highest estimated breeding values for fertility have the highest number of daughters calving within the first six weeks of the calving period.

"In New Zealand, the aim has been to breed good fertility into the herd. The system wont tolerate poor fertility. It is no good having a cow giving 30 litres of milk when the dairies have closed. A 12-week calving pattern, even in herds of 1000 cows, is essential."

"The New Zealand Jersey x Holstein does not have the stature of the import-bred Holstein, but she is definitely not the small 120cm cow that some may imagine. These are good sized cows, aggressive grazers, with ample body capacity and a huge gut making them highly efficient converters of forage.

"That is what the profitability of New Zealand milk production hinges on. Staying profitable with a milk price that has been as low as 8p/litre puts that into perspective," he adds.