When they were conducting trials on Angus cattle in Trangie, NSW, Australia, they had three lines: low, control and high.
The trials which produced the Lowline breed began in 1974, with funding from the Meat Research Corporation, to evaluate selection for growth rate on herd profitability. The aim was to establish whether large or small animals were more efficient converters of grass into meat. This trial continued for 19 years.
The Trangie staff chose one herd selected for high yearling growth rates and another selected for low yearling growth rates, with a randomly selected control group. Satellite herds were established at Glen Innes in the northern tablelands of NSW and at Hamilton in the Western Districts of Victoria to enable climate to be taken into account.
The program involved a detailed evaluation of weight gain, feed intake, reproductive performance, milk production, carcass yield and quality and structural soundness.
The original low line herd comprised 85 cows, which were joined to yearling bulls also selected for low growth from birth to yearling age. From 1974, the low line herd remained closed, with all the replacement bulls and heifers selected from within the line.
After 15 years of selective breeding, the low line herd had stabilised at about 30 per cent smaller than the high line cattle. The bulls were maturing at about 43 inches, and the cows at about 39 inches or less, against 59 inches for standard Angus bulls, and close to the same height for standard Angus cows.