Hunger, thirst, and malnutrition Flashcards
what is the five freedoms regarding nutrition
freedom from hunger and thirst- by ready acsess to fresh water and a diet to maintain full helth and vigiour
why is hunger and thirst two of the most basic, primitive and unremitting of all movivating forces
-failure to eat/drink leads to death
-lack of essential nutrients leads to illness and death
why is hunger not a simple thing
-mild deprivation has little effect
-infact restriction has been shown to increase lifespan in some species
-ad lib feeding of some species can lead to disease and poor repro performance (sows, broilers)
-increasing awareness of abesity as a problem (in humans, dogs, cats, parrots)
is hunger (or thirst) always a good indicative of poor welfare
-is not some degree of hunger necessary to regulate feed intake
-question is at what point do we consider hunger welfare a problem
hunger
the state in which an animal is stimulated to eat
malnourishment
insufficient quality, lack of nutrients, or incorrectly balanced
undernourishment
insufficient quatity
satiety
feedback system that inhibits feeding
what is the motivation behind feeding behaviour
hunger
what is the appetitive and consummatory phases
-appetitive phase: increasing hunger, foraging behaviour
-consummatory phase: feeding
-feed back is + then -
hunger results in increased feeding motivation, expressed as:
-increased activity (hunting/foraging)
-increased aggression (feed competition or resource guarding)
-redirected oral behaviour
what are some redirected oral behaviours
-increased drinking (polydipsia)
-coprophagia (poop-eating)
-geophagia (soil eating)
-stereotypies (knocking on a feeder)
has selaction of species for high growth rate increased hunger when limited fed
-may depend on the species
-pigs: limited gut storage, bouts of absorption
-ruminants: large stomach, continuous absorption
-chickens: moderate storage, continuous absorption
what reflects different animal transport times
species and their gut storage
why are the max transport times of other countries much shorter
-smaller countries
situations that may cause acute hunger and thirst
-feed system breakdown
-transport
-marketing (auction)
-management systems: skip a day feeding- sows, broiler breeders
-forces moulting
situations that may cause chronic hunger
-long term restriction of feed intake
-poor pasture or range conditions
-limit feeding of breeding animals
-subordinate animals when feed is limited
how do you measure hunger
-problems related to hunger affect:
behaviour
physiology
illness
-obsorvational measures: feed intake, rate of eating, time spent feeding
-operant measures: willingness to work for food
when was it found that max hunger sets in after a feeding for pigs
around 5 hours meaning pigs are hungry approximately 19hr/day
what are the types of stereotypies that animals in confinement exhibit
-oral (associated with hunger or feed quality)
-movement (associated with restrictive housing)
does increasing feed volume help with reducing steriotypies
-yes it can help reduce stereotypes/oral behaviours in sows
-has also been shown to reduce:
-cribbing and wood chewing in horses
-feather pecking in poultry (to some degree)
-tail biting in pigs
-tongue rolling in cattle
-so helps to reduce stress and hunger
where can some extensive operations struggle with starvation
-some extensive production systems experience seasonal weight loss, either annually or during dry years
-how much weight loss can be tolerated?
at what point should massive culling occur
-ie.. Aussie outback, blizzards, hay shortages
thirst or water restriction
-defined as insufficient water to meet physiological requirements
-problems of water quality and quantity (eg high sulfur levels)
-apart of basic management but a common problem in both intensive and extensive systems
summary: welfare problems related to malnutrition, undernutrition, or water restriction…
-will appear as:
-abnormal behaviour then physiological problems then illness
-acute and chronic forms
-occurs in intensive and extensive systems
