Someone said you are in FL so I will offer my advise based on that. #1 in my opinion for areas as humid as the gulf coast states, keep him under a fan. From my experience, high humidity and 75degrees will shuch hair as much as 100 degree dry weather. Keep those fans on him to keep air circulating and hair moving. Then it is pretty much as everyone else said, rinse as often as possible, you arent going to get many days in FL that are to cold to rinse, and very few days that are truly cold enough to grow hair. Ambient body temp for cattle varies somewhere around 60 degrees, that means that at that temp they are going to maintain what hair they have and neither grow or shuck hair in most circumstances, that means that we have to get them colder in order to grow hair. When rinsing, if you can do it 3 or 4 times a day, use the coldest water you can and concentrate for 20 minutes or so on neck and heart girth area and legs, you run cold water over the most exposed major arteries then and will circulate cooled blood cooling the calf off. Then use a rice root brush until you think your arm will fall off, this not only trains hair but stimulates blood flow to hair follicles which gives healthier coat. Unless they are going under fans in a cooler, I never leave a calf wet. So blow him out after each rinsing, but dont over dry him use a brush to stimulate hair rather than the blower at home. Keep him in the dark, lack of daylight for prolonged periods makes their body think winter is approaching and they will start growing hair and laying down fat in an effort to prepare for the cold months.