Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
NUTRITIONAL STRATEGIES IN MAMMALS EEOB 625 – 18 February 2004 -----------------------------------------------Assigned Reading: Foods & Feeding, Chapter 6 from Feldhamer et al. (1999) available on Electronic Reserve (Instructions on Course Website) ------------------------------------------------- Components of a Nutritional Strategy • Strategy: A suite of adaptations providing a solution to a major “problem of existence” 1) nutrition, 2) survival, & 3)reproduction Components of a Nutritional Strategy: • Foraging and anti-predation behavior • Feeding habits or diet • Morphological & Physiological Adaptations Feeding Habits of Mammals & their taxonomic distribution (Zoo 625) Feeding Habit • • • • • • Number of Orders Herbivory 10 Frugivory, Graniv., Nectivory 5 Carnivory 4 Planktonivory ? (Krill feeders) 2 Insectivory 10 Omnivory 7 Percent of Species 40 4 12 <1 33 10 Feldhammer Fig. 6.1 Feeding & Locomotory Adaptations • An important “animal” relationship between feeding and locomotion • Traditional basis for grouping mammals into orders by adaptive zone classification (17 of 26 orders), but will this survive cladistic analysis? • Feeding & locomotion provide solutions to two of three major problems of existence: Nutrition, Survival (antipredation) & Reproduction Analysis of Feeding and Related Adaptations Feldhamer’s Approach: Foods and morphological adaptations for capture, mastication, & digestion; e.g., herbivore, carnivore, insectivore Alternative Approach: One based on: 1. Distribution & abundance, including seasonal variation 2. Availability: e.g., Low in nocturnal flying insects 3. Quality: e.g., High (in protein) in insects, fleshy prey, & seeds and nuts, Low in leave & stems of plants • The problem of toxicity in leaves of some plants Herbivory & The Problem with Cellulose Cellulose: 1) Ultra-abundant? plant cell walls & fiber 2) High in energy? polycarbohydrate 3) Unavailable ? Cellulase: Origin & taxonomic distribution? Found only in bacteria & some protozoans Morphological & Physiological Adaptations for Herbivory 1. Finding, securing, & masticating food 2. Providing for (?) anaerobic bacteria & protozoans (microflora) 3. The problem of plant toxins Dental adaptations for herbivory Incisors, molar occlusal surfaces, & masseter Fig. 6.6 Felids: highly derived carnivores Carnassials & claws Schwartz & Schwartz (1959) Fig. 6.2 Basics of Ruminant Digestion • Evolutionary response to toxins or cellulose? • Anatomy of the ruminant “stomach” (R-R-O-A) • Cellulose + microflora SCFA & microflora - hydrolysis of cellulose to glucose - glucose short-chain fatty acids (SCFA) & ____? - microflora are digested in the abomasum Recycling of salivary urea to fertilize rumen bacteria • Foregut & hindgut fermentation: deer vs.horses Recycling of Urea in Ruminants Fig. 6.9