Wild horse and burro herds in the west are rapidly growing. The horses and burros on public lands now number more than 72,000. Federal officials says these animals may starve or die of thirst because the rangeland can’t support them and that they often interfere with ranching. Some politicians want to reduce the wild horse population by making it legal to sell them for slaughter. Jason Bruemmer is associate director of equine science at Colorado State University - Fort Collins. He’s one of the researchers hoping to keep the wild horse population in check by improving fertility control methods. Bruemmer spoke with Colorado Matters host Ryan Warner.