28 June 2002

Matching strains is worth it

EARLY results from a long-term study suggest that matching the strain of Holstein-Friesian cow to the system will help producers manage cow body condition.

With the emphasis on dairy cow fertility, some producers have considered using imported strains such as New Zealand Friesians, says Teagasc researcher Frank Buckley.

"But are they bred to be economically efficient under different management systems? In addition, are there any characteristics which breeders can select to improve profitability?"

The strains being investigated are high genetic merit Holstein-Friesians selected for yield only, medium genetic merit animals selected for yield, calving interval and muscularity and New Zealand Holstein-Friesians, says Dr Buckley.

Even at this early stage, there is evidence of an interaction between strain and feeding system. High genetic merit cows gave the most efficient response to additional concentrates at 0.97kg milk/kg, nearly 2.5 times greater than NZ ones.

"While NZ Holstein-Friesians respond less to concentrates, they are better suited to grass based systems.

"High genetic merit cows tend to be under greater pressure in grass based systems."

This is reflected by body condition score where high genetic cows had the largest decrease and were consistently lower than both other strains, he says.

"Early results also reveal no differences between strains for grazing behaviour. This is surprising as we expected NZ cows to graze more aggressively than higher merit cows."

Current performance Jun 16

Holstein-Friesian strain

High Medium New

index index Zealand

Milk yield 23.6 22.4 20.6

(kg/day)

Fat (%) 3.99 3.92 4.34

Protein (%) 3.27 3.30 3.44

Body 2.61 2.74 2.92

condition score