Again, I have to back up Chey on this. Not to scare you but I've seen some ugly things happen with babies that didn't get the colostrum. One, at the farm I used to work at, was perfectly fine and frolicking the night before, and when we got there in the early morning, he was standing legs splayed, joints swollen, head hanging down - within a few hours pus was draining out his umbilicus - he just had absolutely no way to fight even the most minor infection and it overwhelms their weak little systems LIGHTENING FAST. To me, any foal that was not out of a hyper-vaccinated mare and you didn't SEE nurse within the first few hours, should be checked. It might be just the test and his levels are fine - he might be low and need plasma - but wouldn't you rather know and be proactive then take the wait and see approach and find out when it's too late?