Nutritional Challenges Related to Animal Welfare in Feedlot and Dairy Cattle.

The current article describes select nutritional metabolic disorders that can impact the health and well-being of beef and dairy cattle. These include: Subclinical or clinical acidosis that can lead to rumen, hind gut, or systemic acidosis. Acidosis can disrupt epithelial barrier function in the rumen and hindgut, enabling bacteria to enter the portal vein and form liver abscesses. If rumen acidosis is severe, rumen contractions can be inhibited, or objects may block the esophagus, leading to free-gas bloat. Frothy bloat can occur in cattle fed high grain or legume diets, where froth in the cardia region prevents eructation and the rumen expands to the point that the lungs cannot inflate. Reduced blood Ca levels as a result of milk fever can also impair rumen contractions and is often mistakenly identified as bloat. Reductions in intake as a result of acidosis can lead to an energetic deficit in dairy cows, with heightened metabolism of fatty acids leading to ketosis. Water quality can also impact animal health and welfare, where elevated levels of sulfate in the water can induce polioencephalomalacia as a result of the production of H2S or thiaminases leading to thiamine deficiency. These conditions can occur currently or precipitate a number of other metabolic disorders including lameness, dystocia, uterine prolapse, retained placentas, metritis, abomasal displacement, and mastitis. Ensuring that the nutrient requirements of the host are satisfied and that diets are fed appropriately in an optimally processed form, with high quality water being readily available, are key to avoiding most of the nutritionally linked health and welfare issues in feedlot and dairy cattle.