Transcript NUTRITIONAL STRATEGIES IN MAMMALS

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