Reduced grass production allows overgrazing of pastures by cattle unless stocking rates are reduced. Low intake of grass by cattle causes low intake of energy in their diet. Without energy supplements, the energy levels of the cattle decrease, and the cattle lose weight, become thin, and develop immune suppression and reproductive inefficiencies. The thin cattle become stressed and weak and die of diseases or starvation. Immune suppression causes the cattle’s immunity to be reduced and be more susceptible to disease agents, as well as reducing their ability to respond to vaccines to produce immunity. The incidence of sicknesses and deaths related to bacteria and viruses increases. Reproductive problems develop, such as abortions and infertility. Infertile cows don’t breed back, and infertile bulls don’t settle cows.