the recommended fat inclusion in ruminant diets is 4% and maximum it can be included upto 7% in ruminant ration. reports beyond this is not encouraging. beyond 7% there is a drop in fibre digestion. accordingly you can use for goats.
The safe rate of palm oil is in the rage that Partha suggest (4 to 7 %). The mostly paper suggest a maximum of inclusion level of 8 % of oil in the diets. In fact this level reduce the fiber digestion, but also has beneficial effect because reduce the methane emissions. The level that you decide use need to be related with the production level of goats.
The EE (fat) requirement for different physiological functions of goats varies between 5-8% of diet on DM basis (NRC, 1981).
Palm oil can be supplemented in the ration of dairy goats provided the dietary fat does not meet the above requirements. or it can be supplemented in the ration as bypass fat. The thumb rule is that the bypass fat supplementation in the ration should not exceed 1/3 of dietary fat.
Fat inclusion level in dairy goats should not exceed 8% DM (4- 8% range) to avoid excessive defaunation of the rumen microbes which will be detrimental to structural fibre degradation and utilization.