Thus artificial milk formulas for many species should include this amino acid as a supplement. While on the discussion of milk, it should be noted that not all milk is the same, and attempting to substitute cow's milk for that of other species can have dire results. We will discuss this in more detail as specific examples arise in lecture. As mentioned above, many marine mammals are strict carnivores, feeding entirely on fish and other aquatic species. They too have strict needs that cannot be met completely with plant-based diets.
Fish are generally rich in some required fatty acids.
While terrestrial mammals can produce these components, marine mammals have not needed to do so, since they are easily derived directly from the fish they eat. Fats, however are prone to oxidation and degradation that can occur during storage and freezing. Thus, just supplying carnivorous aquatic mammals with fish that have been frozen or kept in cold storage may not be enough. Rather, a constant supply of fresh fish is required for some marine mammals. We will address this topic again in further discussions.