New Zealand farm trials of feeding a live probiotic to calves have shown a 14:1 return on investment (ROI). Calf growth and subsequent milk production improved significantly, cows were retained longer in the milking herd, and fewer died compared with control groups.

An independently managed MPI Sustainable Farming Fund study used CalfBrew to determine the short- and longterm effects of using a probiotic on calves.

Calfbrew is a fresh, intact probiotic product from BioBrew Ltd, which was developed through Callaghan Innovation-funded research at Lincoln University.

The results showed that the use of CalfBrew increased calf growth rate by up to 10%. As adults the treated calves produced significantly more milk solids in the 2015-16 season. These cows were also less likely to die and were more likely to remain longer in the production herd.

The conclusion was that the use of a fresh probiotic for calves had both short and longer-term benefits and the longerterm ROI was greater than 14:1.

The 2012 study was funded by SSF and DairyNZ and undertaken by the Clutha Agriculture Development Board. The study followed 296 calves on three farms. In 2016, a further SFF and industry funded project looked at the long-term advantages in giving probiotic supplements to neonatal calves.