Prior to giving birth, the cow, ewe, and sow store large quantities of antibodies in the udder. These, together with high levels of protein, vitamins, and fat, make up colostrum, the first milk. During the first few hours of life, their offspring can absorb antibodies directly into the bloodstream from the gut without digesting them. This provides instant protection for a calf, lamb, or pig against diseases to which the dam is immune. Calves born in a confined area are more likely to have severe scours than calves born in the pasture.
Scours tend to be more severe in newly established herds than inclosed herds.
In recently assembled herds, calves are more apt to be exposed to organisms to which the dam has not produced colostral antibodies. Causes Some infectious agent is usually involved in serious scours, either as a primary cause or as a secondary opportunist. Often more than one such agent is involved. Two diarrhea-producing groups of bacteria are Escherichia coli and Salmonella typhimurium. E. coli is normally present in the lower intestine of all warm blooded animals.