Feed Strategy - July 2018 - 29
FeedStrategy ❙ 29
stress is equal to whole-system stress that can lead to local problems or general shutdown. Luckily, antioxidant
nutrition is becoming a recognized field of science for
animals raised under intensive conditions, and it appears
nutritionists are now considering heat stress as one more
causative factor to this generic problem.
What is oxidative stress?
Oxidation is a normal physiological process within the
animal organism. As such, there are counter processes to
neutralize damaging free radicals so as not to cause excessive or irreparable damage. However, oxidative stress
- a condition where normal antioxidant mechanisms are
overwhelmed - occurs under two situations:
First, when animals outright consume free radicals,
like oxidized feed, something that can be easily prevented with quality control and antioxidant feed protection.
Second, when stressful conditions appear in the life
of an animal, including disease, even in sub-clinical
forms, crowding, relocation, over-handling and, of
course, heat stress.
Although there is some innate capacity for internal
handling of oxidative stress, these mechanisms are
deemed insufficient for animals raised under modern intensive production systems. This is clearly a case
where the high genetic capacity for production of modern animals has not been followed by a concomitant
increase in antioxidant capacity. Thus, oxidative stress
prevails, and first it consumes internal and external
natural antioxidant systems including pigments and vitamins such as A and E. It then diminishes the capacity and functionality of organs and systems that depend
on the presence of antioxidants, such as kidneys and
the immune system. In general, animals under severe oxidative stress respond by reduced feed intake,
worse feed efficiency rate (reactive oxygen species are
toxic to mitochondria, affecting energy metabolism),
impaired growth rates and diminished health that may
lead to death due to secondary infections.
Phenolic compounds in animal feeds:
July 2018 ❙ www.WATTAgNet.com