Which of the following is a common symptom of a nutrient deficiency in animals?

A common symptom of a nutrient deficiency in animals is weakness or lethargy. This occurs because essential nutrients play a critical role in maintaining energy levels, muscle function, and overall well-being. When animals do not receive adequate vitamins, minerals, or other vital nutrients, their bodies can become depleted, leading to a lack of energy and a general feeling of weakness, which can manifest as lethargy.

In contrast, excessive weight gain typically results from an overabundance of nutrients or calories rather than a deficiency. Increased aggression may be influenced by a variety of factors, including the environment or social interactions, rather than a specific nutrient shortage. Rapid growth is usually associated with an adequate or excess supply of nutrients, not a deficiency, as animals require the right balance of nutrients to support healthy growth. Thus, weakness or lethargy serves as a significant indicator of potential nutrient deficiency in animals.