Changes

==Pathogenesis==

==Pathogenesis==

As ruminants, dairy cattle are designed to subsist on predominantly forage diets; however, to meet the energy requirements of pregnancy and lactation, they are offered diets high in carbohydrate-rich concentrates. Beef cattle and sheep may also face this problem, but generally to a lesser degree as they are raised more extensively and their energy demands are considerably lower.

As ruminants, dairy cattle are designed to subsist on predominantly forage diets; however, to meet the energy requirements of pregnancy and lactation, they are offered diets high in carbohydrate-rich concentrates.   

Field observations suggest that periparturient cows are at risk of subacute ruminal acidosis because of the time required for the rumen microflora and papillae to adapt to increased intakes of concentrates immediately before parturition and during early lactation when feed intake increases rapidly to meet the energy needs of high-producing dairy cows. The adaptation of the ruminal microflora and papillae from a system appropriate for forage to a system capable of utilizing high-energy lactation rations requires a gradual change over a period of 3-5 wk.

Field observations suggest that periparturient cows are at risk of subacute ruminal acidosis because of the time required for the rumen microflora and papillae to adapt to increased intakes of concentrates immediately before parturition and during early lactation when feed intake increases rapidly to meet the energy needs of high-producing dairy cows. The adaptation of the ruminal microflora and papillae from a system appropriate for forage to a system capable of utilizing high-energy lactation rations requires a gradual change over a period of 3-5 wk.