Research suggests there's a great deal of variation in individual animal consumption of supplements, says Jan Bowman, a professor in the Montana State University-Bozeman Animal and Range Sciences Department. Bowman and MSU colleague Bok Sowell analyzed research studies on animal supplement intake, and found that trough size, animal dominance and other factors can influence how much supplement each animal gets. Over-consumption of supplement by certain animals wastes money and has the potential to be harmful to the animals. Animals not getting enough can reproduce or grow at a reduced rate, have decreased feed efficiency and depressed immune systems. Producers select the amount and type of supplement depending on mineral deficiencies in the forage and other site-specific factors.
Producers usually determine a target level of intake per cow or sheep.
Some producers hand-feed certain animals to make sure they are getting a desired amount. But often producers will put out a bulk amount which is intended for the whole herd or flock. The producers usually assume that each animal is getting an equal portion, but often that's not the case, says Bowman. When animals have free access to supplement, such as in blocks or liquid form, some animals over-consume, while some don't get any. Trough space can influence competitiveness by the animals.