What Causes Runt Cattle?

Runt cattle are those that are small or stunted compared to others of the same age. Some cattle are born smaller than others, while some are born the same size and weight but do not grow and develop as well as those around them. The reasons can be due to genetic or environmental factors, but there are several causes of runt cattle.

  1. Inbreeding

    • If closely related animals are mated, the resulting calf is often small and will have less vigorous growth than normal. This can happen quite often in small, single-bull herds where replacement heifers are kept. If the same bull is kept for three of more years, he will be covering his own daughters, and the chances are much higher of deformed and sickly calves being born. Those that survive will probably always be runts.

    Nutrition

    • Calves that do not get adequate nutrition during the first six weeks of their lives will never reach their full growth potential. This can happen if the mother has a poor milk supply because of age, illness or inadequate feed intake. In Australia, small runt cattle are often referred to as "drought babies" because Australia is prone to droughts, in which some cattle die due to the lack of pasture. Hand-reared calves may end up as runts if a quality calf food is not used.

    Worms and Parasites

    • Cattle are affected by a range of internal worms, flukes and external parasites. These vary from area to area. If farmers don't control parasites, they will affect the condition of cattle and they will lose weight, lose condition, their coats will lose their gloss, and in severe cases of worms, they can even die. If young cattle and first-calving heifers don't get adequate worm and parasite control, it can permanently stunt their growth.

    Illness

    • Cattle can suffer from a range of illnesses. Some can be due to mild poisoning from pasture weeds, and many cattle illnesses lead to diarrhea because of the rumen digestion system. If young cattle are not treated for illnesses, although many will recover naturally over time, they will become stunted and not reach full growth potential if they are allowed to suffer a prolonged period of illness. If a cow is ill for more than 24 hours, a vet should be called.