Stirling Products' (ASX:STI) second study into the effects of its lead beta agonist growth promotion product ST810 in broiler chickens has shown positive preliminary results, according to the company.

ST810 is a metabolic modifier that repartitions energy with the aim of creating carcasses with more meat and less fat.

The study was conducted at Massey University, New Zealand under the supervision of Dr Ravi Ravindran, on 120 male and 120 female 21-day old broiler chickens. There were five different treatment groups of 24 birds per group -- a control, a group receiving 1 ppm, 2 ppm, or 5 ppm of ST810 and an additional group that were fed a diet containing 5 ppm of ST810 supplemented with 100 ppm of zinc bacitracin (a commonly prescribed antibiotic).

Preliminary results from the study found that the 5 ppm dose produced a reduction in feed content of up to 5.5 per cent. Leg muscle weights (lean meat) were increased by up to 11 per cent and body fat was reduced by up to 28.6 per cent. The inclusion of zinc bacitracin had a variable effect on the results at 5 ppm.

"There are currently no commercial beta agonist growth promoters available to poultry producers," said Stirling Products managing director Calvin London in a statement. "The industry is dominated by antibiotics for this purpose, which are under increasing scrutiny from the public and the Food and Drug Administration who have started to withdraw several of these antibiotics."