Sick animals are not productive animals, but will continue to consume feed since they have a requirement for body maintenance. They will continue to excrete nutrients in their manure. All animals should be on a regular health and herd management program. They should be vaccinated for disease regularly and monitored for special diseases.
All domestic livestock animals can be affected by parasites. Parasites will infest the intestines and can result in substantial decreases in performance. Whenever this happens, the efficiency of nutrient utilization is going to decline and influence nutrient excretion. All animals should be on a regular deworming and parasite control schedule.
Toxins in the feed or water may also influence animal production. For example, during a drought year forage quality will often decline, and toxins, such as nitrates, may be taken up from the soil by plants and influence animal production. Plant growth stress can also result in the formation of mycotoxins in the feed; this can occur in both feed grains and forages. These toxins can result in decreased production, as well as sickness and death, and may be a risk to human health. Whenever toxins are believed to be a problem, it is important to test feed and water supplies to ensure the adequate consumption of un-contaminated feeds and water.