Which of the following is a consequence of acidosis in ruminants?

Acidosis in ruminants is a condition typically characterized by an excessive accumulation of acid in the rumen, often associated with high grain diets that lead to rapid fermentation and subsequent production of lactic acid. This metabolic disturbance can have several adverse effects on the animal's health and production.

Decreased milk production is a consequence of acidosis due to the negative impact it has on the cow's overall health and metabolic functions. When acidosis occurs, it can lead to inflammation of the rumen lining and changes in the microbial population that adversely affect digestion and nutrient absorption. Consequently, when a ruminant is experiencing acidosis, its ability to effectively convert feed into energy and nutrients diminishes. This reduction in feed efficiency can lead to lower milk yields as the cow's body redirects energy to cope with the metabolic disturbance instead of investing it in milk production.

In contrast, the other options describe outcomes that generally would not occur with acidosis. Increased feed intake is unlikely since animals experiencing acidosis often exhibit signs of distress and may eat less. Improved weight gain could be a result of optimal feeding practices but would not typically be associated with acidosis, which tends to impair weight gain due to reduced feed efficiency and health issues. Enhanced immune response also does not correlate