Ponies that are used for sports and are trained intensively, it’s best to give the minimal dosage. In case they are only used for recreation or light work, it might be sufficient to give a little less, for example 125 grams. Shetland ponies and other smaller breeds can suffice with a lower dosage (between 50 and 100 grams)
The general guideline for calculating the right amount of BASIC is +- 40 grams per 100 kg weight.