TheBmomma wrote:
... he has kept every mare on the property in heat for 3 weeks. He reaches through the fence and licks and nibbles them....

This is a common "cause and effect" mistake. The mare's repro cycle is not influenced by external factors (besides photoperiod/temperature, and any drugs given to her). The presence of a stallion or gelding will not bring her into heat or keep her in heat- that's what estrogen and LH and FSH produced by an active follicle and pituitary gland do. What you are seeing is either a true display of "heat" that's going on inside the mare regardless, or false "heat" behaviors that aren't actually aligned with her reproductive activity. It's like the difference between getting an A on a test because you are smart, vs getting an A on a test because you were given the test... if that makes any sense...