As long as he eats his 25 oz for a few more months he will be fine. 30 oz is an average, so I think your lo should be OK. His need for milk will slowly start decreasing and at 11 to 16 months he will need approximately 19 oz, so you see what is the trend.
Right now his milk contributes to 90 percent of his calorie intake while at 1 year he will be getting only 50 percent from milk, if you, of course, keep on nursing that long :wink: .