Ingestion Behaviors (feeding and drinking) Domestic Animal Behavior

Transcription

1 Ingestion Behaviors (feeding and drinking) Domestic Animal Behavior

2 Otline General principles Physiology of ingestion Defense of body weight and composition Meal patterns, Social facilitation, Palatability, Temperatre Species-specific information (mixed throghot principles)

3 Anatomy of the digestive tract

4 General principles Animals mst eat and drink fresh water (with rare exceptions, sch as the Kangaroo Rat, Qokkas and the Tammar Wallaby) All domestic animals mst eat food/feed and drink water Rminants drink more water than non-rminants, bt they drink less often with camalids drinking less freqently Ingestion leads to elimination Kangaroo rat (USA) Qokkas, Rottnest Island W. Astralia Tammar Wallaby, W. Astralia

5 General Principles Yong animals have a growth crve ntil adlthood Animals grow slowly, then more rapidly (dynamic phase), then they platea in body weight One can slow the growth crve by limit feeding

6 General Principles Remember we have for types of biological types among domestic animals: Rminants (cattle, sheep, goats, llamas) Non-rminant herbivores (horse, rabbit) Non-rminant omnivores (pigs, poltry) Carnivores (dogs and cats) Clearly each type mst be fed differently and their feeding behaviors differ Generally, the time it takes to eat and the mass of feed eaten depends on the biologically relevant food s natral ntrient density Low ntrient-dense foods like hay & grass reqire eating large amonts high- ntrient-dense foods like grain+soybean or meat don t reqire as mch mass of food eaten to obtain the same amont of ntrients

7 General Principles Major ntrients Water (can be drank directly, or obtained throgh food) Protein Carbohydrates Fats or lipids (fat, oil, or wax) Fiber Vitamins and minerals General ntrient densities Meat is a nearly complete, ntrient-dense food Corn-soybean diet spplemented with vitamins and minerals provides all the ntrients any animal needs Forage is high in fiber (some highly digestible to rminants), bt has valable levels of other ntrients Feeding the wrong diet to a given speices may case health problems

8 General Principles Obesity is a large problem in domestic animals Ø Farm pigs have been bred for leanness in recent years Ø Dogs and cats in the USA are increasingly obese Ø Herbivores are less commonly obese (bt it happens) Ntrients (calories) taken in + Activity level = Body composition

9 Physiology of Ingestion Ø Hormonal commnication between the brain and the GI tract control feed intake (hnger and satiation) Ø Hormones that increase feeding: Ø Neropeptide Y (NPY) Ø Agoti-related protein (ARP) Ø Hormones that sppress feeding: Ø Melanocyte-stimlating hormone (MSH) Ø Cocaine-Amphetamine related transcript (CART) Pls: Leptin, Gt peptides, Inslin, Glcagon, Grelin, CCK and others

10 Physiology of Ingestion The environment has a large effect on food and water intake Warm temperatres lower and cold temperatres increase feed intake Disease (fever especially) cases inflammation and redced feed intake

11 Feeding Behavioral Principles Social facilitation Hngry animals, aggressively eating (or not), increase motivation to feeding of other animals Animals prefer company while eating Social sppression Social stats can impact feeding and drinking Harris on the pig, 1883

12 Feeding Behavioral Principles Meal Patterns Most feeding is done according the circadian cycle of the species Dirnal, noctrnal, crepsclar Mechanics of feeding Teeth vs lips vs tonge Bite, grasp, scoop Chew Swallow Eat-drink-eat-drink seqences Pig feeding behavior Cattle feeding behavior

13 Feeding Behavioral Principles Food related aggression Animals can be protective abot their food Many animals do not like being messed with while feeding Food-related aggression is common among domestic animals Modifying dog food aggression via positive reinforcement

14 Feeding Behavioral Principles Palatability Depending on the species, different foods have different preferences Even animals in the same species vary in their preference for certain foods Preference vs. Aversion Food neophobia (more common in carnivores and non-rminants) Animal genetic aversion to some poisonos plants or other foods

15 Control of Food/Feed Intake Scientists have been looking for molecles and methods to increase or decrease food intake. Animals, generally, eat to reach a calorie target Animals can have ntrientspecific cravings (ex., fiber, salt, microminerals) Temperatre has a large effect on feed intake (see graph)

16 Ad Libitm vs. Meal feeding Allowing some dogs to eat ad libitm cases them to become obese; others not so mch

17 Food qality impacts feeding levels Food qality changes present and ftre feed intake

18 Special times that change feed intake Temperatre Partrition Lactation Stress Pberty reqires a certain age, weight and body composition

19 Defense of Body Weight Animals eat for: maintenance, growth, pregnancy, or lactation. If the amont of ntrients are limited, animals will attempt to at least meet their maintenance needs for ntrients Adlt animals (like people) defend a set-point body weight An animal s set point will be different among animals of the same species Physiological internal signals change the set-point feed intake level Diet density has a large effect on calorie intake Animals like salt, fat, sgar, and for some species, meat

20 Feeding behavior of rminants Rminants have different physiological mechanisms that control feed intake Glcose is less critical than for nonrminants Bacterial digestion of ntrients, especially, fiber and protein change the ntrients that reach the small intestine

21 Behavioral problems associated with ingestion Obesity Anorexia Pica Specific hngers Grass eating by dogs Coprophagic Psychogenic polyphagia or polydipsia Often associated with new pet introdction Adipsia (no drinking) and hypernatremia (high NaCl in blood associated with dehydration) Not drinking water can be a physiological problem