22 November 1996

ITALIANS SKIP

A GENERATION

Genetic progress in the Italian dairy industry is moving ahead at pace. Jessica Buss reports

ITALIAN bulls with the potential to enter progeny testing are being born to heifers that are only 11 months old by recovering eggs from two-month-old baby heifers.

So says Theo Pieters who manages the nucleus project known as ROYAL (reproductive overdrive yielding additional livestock) for the semen company CIZ research and genetics.

So far, six calves have been born to 11-month-old dams and the company has plans to recover eggs from 20 to 30 animals a year.

It is hoped that one in three of the bulls born will enter the progeny testing scheme.

"We are able to make unique crosses skipping a generation," he says. This takes six months off the generation interval that is achieved by non-surgical recovery of eggs or oocytes on eight-month-old maiden heifers.

Calves of two to three months are given hormone treatment so that their ovaries develop. A small surgical incision allows the immature eggs to be collected using the oocyte recovery technique. This uses an ultrasound scanner to identify the immature eggs and a needle to aspirate them from the ovary.

Up to 50 eggs are recovered for in-vitro fertilisation (IVF) of which 10 may be fertilised, claims Mr Pieters. After maturation in test tubes for seven days an average of 2.5 embryos are suitable for transfer into recipient animals. The procedure is only carried out once on each animal.

"This shortens the generation interval but with high risk of failure," says Mr Pieters. "But this high risk means there is also a possibility of extremes which could produce a top bull."

Young females selected to breed bulls are those with good pedigrees and the sires used for IVF are proven bulls or high potential test bulls. Current selections are based on predicted kg of protein, and the best Labelle and Fatal daughters have had eggs recovered.

Royal breeding

The first Italian nucleus herd breeding programme, named ROYAL, was set up in February this year. This aims to give precise selection of bull mothers based on reliable estimates of breeding values.

The herd will have 150 heifers that can be assessed without the preferential treatment that can occur on farms, says project manager Theo Pieters. Of these heifers one in five will be selected as a bull mother – to produce 50 bulls a year for testing.n

An 11-month-old mother and her son born using oocyte recovery and ET.

Collecting oocytes from 2-3 month-old calves helps reduce the generation interval, according to Theo Pieters.