A novel bacterial strain isolated in Australia, Propionibacterium jensenii 702 (PJ702), was examined for its potential as a direct-fed microbial (DFM) to improve weight gain in calves.
Holstein bull calves, 24, were randomly allocated into a treatment or control group and held under simulated commercial calf rearing conditions. Both groups were treated identically, with the exception that the treatment calves were given between 1.1×108 and 1.2×109 cfu/(kg day) of PJ702.
Faecal
recovery of PJ702 from the treatment calves from week 2 indicated successful
gastrointestinal transit of the bacterium, and blood haematology and
biochemistry indicated no adverse effects following PJ702
administration.
Weight gain
There were
improvements in weight gains with the treatment group during both the
pre-weaning and the weaning period.
Eighteen weeks after cessation of
treatment, and removal to an extensive farming operation, treatment calves
remained heavier to the control calves, with a final weight difference between
the groups of 21.3 kg.