Section 5a-h Flashcards
0
Q
What are the subclasses associated with herbivores?
A
- Grazers, Browsers, Folivores - Nectarivores - Frugivores - Granivores
1
Q
What are the subclasses associated with carnivores?
A
- Carnivores & piscivores
- Insectivores
- Other microfaunivores
2
Q
What types of prey do carnivores and Piscivores eat? What part of these prey are ingested?
A
- Vertebrates, fish - Soft Tissues - Indigestible Animal Tissues
3
Q
How are vertebrates & fish digested by carnivores and piscivores?
A
- Autoenzymatic digestion (by the animals own enzymes)
4
Q
Explain the variable fat content and composition of fish, give examples.
A
- oily fish store fat in muscles (sardines, herring)
- 20% + fat pre-spawning
- <1% fat post spawning
- non-oily/white fish store fat in liver
- <2% fat (cod, haddock, plaice, halibut)
- Cold water usually higher fat
5
Q
Explain the composition and digestion of vertebrates eaten by carnivores and piscivores.
A
- Highly digestible
- High in protein
- Balance of EAAs similar to the requirements
- Good source of minerals, vitamins
- LOW in Ca, IF prey is eaten whole
6
Q
What are the components of indigestible animal tissues that carnivores and piscivores eat? give examples.
A
- Bones - Fur (mammals) - Feathers (birds) - Scales (reptiles, fish)
7
Q
Explain how indigestible animal tissues are “dealth with”.
A
- Separated from soft tissues before ingestion - Separation in the gizzard (birds) and then egested (pellets) - Not separated: decrease digestibility of total diet, some digestion of bones (Ca)
8
Q
What do insectivores eat? What other feeding classification can the be?
A
- Insects - autoenzymatic digestion - Can also be gummivores - eat exudates from trees & shrubs, many exudates HIGH in Ca
9
Q
what parts of insects are ingested in the insectivore diet?
A
- Soft tissues - Indigestible chitinous exoskeleton
10
Q
Explain the composition and digestibility of the soft tissue portion of insects.
A
- Highly digestible
- High in protein
- Fat content variable
- balance of EAAs similar to requirements - good source of P, trace minerals, vitamins - Low in Ca (bones, snail shells, egg shells may be eaten)
11
Q
What is the composition of the indigestible chitin portion of the insectivore diet?
A
- Chitin is a carbohydrate - Chitin content is variable 18-60%
12
Q
Explain the seasonality of the insects of an insectivore diet.
A
- Adult insects may be seasonal in temperate areas - some adult/larval insects - in tree bark or in the group during the winter
13
Q
Explain the morphology of insects.
A
- have a chitinous exoskeleton - three-part body (head, thorax, abdomen) - three pairs of jointed legs - Compound eyes - two antennae
14
Q
What are Microfaunivores?
A
- Animals that eat other invertebrates, NOT insects
15
Q
What do mammal and bird microfaunivores eat?
A
- Annelids: worms - Molluscs: snails, mussels, oysters, clams (calcareous shells) - Molluscs: squid, octopus (chitinous beak) - Echinoderms: sea urchins, starfish (calcareous exoskeleton) - Arachnids: Spiders - Crustacea: crabs, lobsters, shrimp, crayfish, krill
16
Q
How do microfaunivores digest?
A
- autoenzymic digestion of soft tissues
17
Q
The soft tissues of the mucrofaunivore diet are similar to which other food?
A
- Insects
18
Q
How do microfaunivores “deal with” the indigestible shells and exoskeletons in their diet?
A
- Remove shell or exoskeleton before ingestion - Eat squid whole, then egest beak (cormorant, albatross) - Eat molluscs whole, crush shell in gizzard (eider duck) - Produce chitinase enzymes, at least partially digest chitin, energy value of chitin usually low (king penguins, chitin digestibility 85%)
19
Q
What are grazers, browsers and folivores? what do they eat?
A
- Eat vegetative parts of plants, leaves, stems - Grasses (monocotyledons), broad-leaved plants (dicotyledons), both herbaceous (forbs) & woddy
20
Q
How do grazers, browsers and folivores digest their food? What two occurances may be associated with this diet and the styles of digestion associated with it?
A
- Alloenzyme digestion + microbial enzymes - microbial fermentation essential for digestion of plant cells walls (cellulose, hemicellulose) - coprophagy, caecotrophy may occur
21
Q
What is the exception to the grazer, browser, folivores group?
A
Giant Panda: autoenzymatic digestion - cell contents - highly digestible, do not need microbial fermentation
22
Q
What is the food composition of the grazer, browser, folivore diet? (EAAs, specific AA, Na, Fibre)
A
- Protein: fairly good balance of EAAs in young, green plant material
- LOW levels of methionine, lysine
- variable Na source (may need salt licks): aquatic leaves & roots are a good Na source
- Cell wall “Fibre” - poorly digestible, hinders digestibility of cell contents
23
Q
How do Folivores deal with the cell wall content of their diet?
A
- physical breakdown, chewing (rumination/merycism) in mammals
- muscular gizzard in birds
- requires microbial fermentation
- Eating manure vegetation: higher cell wall content
24
What do young folivores birds supplement vegetative plant material with? and why?
- Insects - Other invertebrates - grains - seeds - to obtain extra energy and protein
25
What do nectarivores primarily eat and how do they digest?
- nectar, honey, honeydew (produced by aphids, sap-sucking insects) - pollen - autoenzymatic digestion
26
What is the composition of pollen for nectarivores?
- high protein 7-40% DM - good source of vitamins, minerals
27
What is the composition of the nectarivores diet? How digestible is this? (sugar concentration, AA, Lipids
- a very dilute sugar solution (sucrose, glucose and fructose)
- may contain very LOW levels of amino acids, lipids
- Poor amino acid balance
- highly digestible
28
What do grainivores eat?
- seeds, grains (seeds of grasses), nuts
29
What is the composition of the Grainivores diet? (8 pts)
- high in starch
- low to moderate protein
- AA balance is variable, may be poor
- Low in fibre (without seed coats/husked)
- good source of many vitamins, minerals
- Variable oil content
- LOW in Ca
- moderate P content
30
How do grainivores deal with the tough seed coat in their diet?
- may be cracked by teeth/beak and discarded before ingestion - may be chewed by teeth, or ground in the gizzard and the seed digested
31
What is the seasonality of the grainvores diet?
- seasonal in temperate areas - available all year in tropics
32
What do Frugivores eat?
- succulent, fleshy fruits
- Dry fruit
33
How do frugivores digest their food/
- autoenzymatic digestion
34
What is the composition of nutrient-dilute fruits? Give two examples of this type of fruit.
Nutrient-dilute fruits - High water content ~5% DM - high carbohydrates, fructose, glucose, sucrose - LOW amino acids - Low fibre
- apples and blueberries
35
How do frugivores deal with the indigestible tough fruit coat and seeds?
- may be discarded before ingestion - seeds may be collected in the gizzard and regurgitated - seeds may be chewed cracked in the bill or ground in the gizzard, and the protein in the seed digested
36
What is the seasonality of the frugivore diet?
- fruit is seasonal in temperate areas - available all year in tropics
37
In carnivores, how does energy content relate to nutrient deficiencies?
- if energy sufficient: nutrient deficiencies unlikely - if flesh only eaten (no bones), LOW Ca
38
In insectivores, how does energy content relate to nutrient deficiencies?
- if Energy sufficient, LOW Ca
39
In omnivores, how does energy content relate to nutrient deficiencies?
- if energy sufficient - nutrient deficiencies unlikely - high diet Variety
40
In herbivores, how does energy content relate to nutrient deficiencies?
- low/poor/variable protein, AA balance, Methionine, lysine, Na, Ca, Ca:P - high fibre, decreases diet digestibility
- diet Variability essential
41
Explain the trends within a coyote diet composed of white-tailed deer, snowshoe white hare and laboratory mice.
- DM: hare, mouse, deer - Ash: hare, mouse, deer - CP: deer, hare, mouse - EE: mouse, deer, hare - CF: deer, hare, mouse - NFE: hare, deer, mouse - GE: mouse, deer, hare
42
What is the range of dry matter content of a carnivorous diet? How is this value given in nutrient analyses?
- % - water content not usually given (100%-DM)
- all carcasses within 60-80%
- nutrient content can be given as %DM, dry matter basis or 'As Is'. 'As Fed', fresh weight basis
43
Explain the CF content of the carnivorous diet.
- may be given as ADF or NDF - herbivore diets - plant cell walls - from GIT contents
44
In the carnivorous diet, what does NFE indicate? How is this calculated?
- NFE value reflects errors in all other values (may even give -ve value)
- calculated by subtraction, not analyzed (100-(Ash + CP + EE + CF)
45
In carnivores, what are the normal ranges for GE in both animals and plant foods? What values would indicate high Ash values? What values would indicate obesity or sedentary living?
- normal range for food analyses: (4-6kcal/g - both animal and plant foods) (\< 4 kcal/g - usually means very high ash values) (\> 6 kcal/g, 7 - 7.5 kcal/g - usually means obese prey animals, pre-hibernation/torpor, pre-migration, lab animals)
46
Solve. A deer carcass contains 1.48 kcal/g GE on a fresh weight basis, convert to DM basis if the moisture content is 73%.
DM = 100 - 73 = 27% 1.48 x 100/27 = 5.48 kcal/g DM
47
Solve. A deer carcass contains 5.48 kcal/g GE on a Dry Matter basis, convert to fresh weight basis. (DM = 27%)
- 5.48 x 27/100 = 1.48 kcal/g Fresh Wt
48
What trends are observed in the digestibility of the carnivorous coyote's diet? (white tailed deer, snowshoe hare, lab mice) (DM, CP, EE, GE)
- DM: deer, mice, hare - CP: deer, hare, mice - EE: mice, deer, hare - GE: deer, mice, hare
49
How digestible are the aspects of in carnivore diets (lean tissue, adipose tissue and bone/indigestible components)?
- lean (muscle) tissue & adipose tissue, highly digestible
- digestibility decreases with indigestible components present in the whole carcass (Ca is supplied from bones)
50
What is the energy digestibility equation of intact carcasses ~90%?
GE x 0.90 = DE
51
Explain the trends for gastric digestion between the two groups of avian carnivores?
- The owl group is higher gastric pH, % food appearing as pellet and % bones in pellet
52
What are the two groups of avian carnivores?
- hawks, falcons, eagles - owls
53
What is the difference between the two avian carnivore groups?
hawks, falcons, eagles: - more often tear flesh of prey - less often eat prey wholes - but eat at least some of the bones
Owls: - often ingest prey whole
54
What is the difference in gastric pH between the two types of avian carnivores?
- Less acidic gastric pH in owls: decreased bone digestion and Ca availability
55
What is the difference in % food/bones appearing as pellet between the avian carnivore species? Why does this difference exist?
- Owl pellets are more useful for food habit studies than other group - bones in pellets from hawk/falcon/eagle are less representative of diet because of greater digestion, thus their pellets are less useful for food habit studies
56
Compare the digestive efficiency of carnivorous mammals vs. carnivorous birds.
- ME in birds is lower than DE in mammals - NOT because the digestive efficiency is lower - DE in birds is similar to DE in mammals
57
In the insectivore and microfaunivore diet: what is the general Ca:P ratio of invertebrates? What is the level of Ca? What amount of Ca do most animals need in the diet?
- Ca:P lower than 1:1
- Ca LOW
- most animals need ~0.5% DM Ca in diet
58
What other diet is similar in composition and digestibility to the insectivore and microfaunivore diet?
- food composition and digestibility very similar to vertebrate prey
59
In the insectivore and microfaunivore diet: What problems are caused by the chitin skeletons? How can this be managed?
- Ca in exoskeleton/shells decreases DM digestibility
- Provide Ca in the diet
- decreased CP & EE digestibility by physically blocking access of digestive enzymes to protein and lipid
- To manage: some mammals/birds produce chitinase enzyme which at lest partially digests chitin: 35-85% digestibility of chitin
60
What foods are included in the Herbivore diet? What is not included in their diet?
- eat leaves, stems, vegetative parts of plants
- may include algae (marine mammals), lichens
- does NOT include fruits, seeds, plant exudates, pollen
- USUALLY NOT fungi
61
What are Lichens? how does this symbiotic relationship work?
- algae are autotrophs and manufacture organic compounds from water, CO2 and minerals using solar radiation, photosynthesis
- algae then pass organic compounds to fungi (heterotrophs need organic compounds in food) - Fungi provide shelter for algae which are normally aquatic
62
How do forage and browse vary?
- quality, composition, energy content, digestibility, quantity - with: time & seasonally
63
What factors affect the variability of forage and browse ?
- species of plant
- part of plant (leaves usually higher quality than stems) - Age of plant (younger plants higher quality)
- stage of growth of plant (when grasses start to produce seeds, leaf and stem quality decreases)
- effects of climate
- effects of soils fertility and minerals (N, P, K, needed for growth, added as artificial fertilizer)
- plant defence chemicals (toxins, anti-nutrients, to protect plants from predation)
64
What is the composition of forage and browse in the herbivore diet? How are these components digested?
Cell walls: - pectin, soluble - hemicellulose, insoluble - cellulose, insoluble - lignin, insoluble, indigestible Cell contents: - soluble carbohydrates (~NFE) - protein (~CP)
65
How do the cell wall contents compare within species of the herbivore diet? (grasses, forbs, woody twigs, leaves) How do acorns, fleshy fruit and mushrooms compare in cell wall content?
- Grasses: immature \< mature
- Forbs: immature \< mature
- Leaves: growing \< fallen/weathered
- Woody twigs: immature \< mature
- Acorns \< Fleshy fruits \> Mushrooms
66
What is the relationship between cell wall content and maturity of herbivore diets?
- cell wall content increases with maturity - more cell wall material is deposited with time - lignin may be deposited after the pectin, cellulose, and hemicellulose
67
How does the accessibility of forage and browse in the herbivore diet change? (6)
- accessible with season - as snow depth increases, smaller browsers may gain access to browse that is normally too high to reach - depends on snow compactness/ice crust - some large herbivores, too heavy to walk across surface of snow, may 'breast' trees (walking over them) to gain access to higher browse - some herbivores need access to forage below snow - caribou 'crater' digging down to forage (extra energy expense)
68
What is the Ash composition of forage in browse in the herbivore diet?
- minerals important to herbivore foods - Na, K, Na:K, Ca, P, Ca:P - Na, Ca, P - may be LOW - K HIGH in most plant material - Na:K, Ca:P may be unbalanced
69
What is the Na:K seasonality and requirement of the herbivore diet?
- K highest in spring, decreases through to winter
- Most herbivores need ~0.15% DM Na in diet - 0.15% \> 1500 ppm (~1:4 Na:K)
70
What happens with a High K, low Na imbalance in herbivores?
- need to conserve Na - use of salt licks helps to redress imbalance, high levels of K
71
What herbivores might Na be limiting for? (8)
- white tailed deer - moose - reindeer - groundhogs - meadow voles - fox squirrels - prairie dogs - elephants (mine for salt in caves at night)
72
What are the requirements and relationships of Ca, P and Ca:P in the diet?
need Ca ~ 0.5% DM in diet (lichen low)
- need Ca:P 1:1 - 2:1
- willow twigs, pond lily stems too little P
- Lichen just about adequate ratio although Ca is LOW
73
What happens when Ca is low in the diet? (5)
- osteophagia (bone-eating) supplied Ca, P, Na - some rodents may chew shed antlers - snails may be eaten - Higher Ca requirements for birds laying eggs (may eat grit, broken egg shells) - Higher Ca requirements for lactating mammals
74
Make a comparison in digestive efficiencies between herbivores and carnivores.
- DM, CP, EE all lower than carnivores - CF similar in - ruminants & non-ruminants although strategy different
- NFE somewhat higher in non-ruminants
- DE lower in both ruminants & non-ruminants when compared to carnivores
- Energy density (GE) of vegetative plant food is less than that of animal flesh& adipose tissue
75
What are the different strategies in digestive efficiency of CF between ruminants & non-ruminants?
Ruminants: - rate of GIT passage slower - more efficient digestion - less material eaten Non-ruminants: - faster rate of passage through GIT - passage through GIT not restricted by omasum - CF digestion less efficient, bacteria have less time to ferment - Caecum fermenters may be at low end of range - more material may be eaten (colon fermenters) or food chosen more selectively (caecum fermenters)
76
What is the CP composition of weed seeds and cultivated grains in the granivore diet?
CP: - good source - slightly higher in weed seeds cf cultivated grains
77
What are the 3 parts of a seed?
- husk - germ - endosperm
78
What is the CF composition of weed seeds and cultivated grains in the herbivore diet?
CF: - moderately high in weed seeds - some seed-eaters remove husk/seed coat before eating (takes time) - higher food quality (inc. digestibility) VS. less time available for foraging - low in cultivated grains - cultivated grains bred for thinner husk, and for larger size - less seed coat/g
79
What is the EE composition of weed seeds and cultivated grains on the herbivore diet?
EE: - good in weed seeds, in germ - lower in cultivated grains, except oil seeds (bred for larger size, larger endosperm, less germ/g) - 1-2% EE in diet of seed-eaters, EFA needs should be met (fats in plants, mono or polyunsaturated
80
What is the NFE composition of weed seeds and cultivated grains of the herbivore diets?
NFE: - soluble carbs/sugars, mostly non-structural carbs (starch) - good in weed seeds - HIGH in cultivated grains
81
What is the Ash/Ca/P/Na composition of weed seeds and cultivated grains of the herbivore diet?
Ash: - weed seeds, variable partly due to Ca levels - eater of weed seeds, must eat a variety - Cultivated grains, ash LOW, Ca LOW
82
What is the AA composition of weed seeds and cultivated grains of the herbivore diet?
AA: - profile not given, methionine, lysine, may be low in some species MUST eat a variety
83
What is the GE and Digestibility of weed seeds and cultivation grains of the herbivore diets?
GE: - Weed seeds, good energy source Digestibility: - cultivated grains, NFE, CP, EE, well digested ~80% - weed seeds, may be less digestible - higher fibre levels, smaller seeds - higher level of tannins, trypsin inhibitors, other toxins/antimetabolites - if seeds are eaten, plants reproduction have failed (unless some seeds pass through GIT undigested) - seeds/grains seasonal in temperature areas, must combine with other food sources - grains are excellent energy source BUT: - not a balanced feed - monoculture agriculture makes grains available, may rpesent a problem to wildlife (migrating birds) - fewer hedges with weed seeds, also problem - BUT highway medians and verges now being planted with wild species, left unmowed
84
What is the digestibility of nuts by small rodent grainivores?
- high digestibility, cf ~90% in carnivores eating complete carcasses - both vole and mouse remove shell/husk before eating nuts
85
What is the composition breakdown of vegetative plant material by frugivores?
- CP: HIGH 25.7-33.3% - CF: moderate 12.5-12.9% - NFE: moderate 31.2-44.5% - EE: moderate 1.4-3.1% - Ash: HIGH 7.9 - 12.2% (usually ~5% not due to high Ca levels) - Ca & P: Ca LOW 0.03-0.16%, P HIGH 0.52-0.61%, Ca:P poor
86
What is the composition breakdown of Fruit in the frugivore diet?
- CP: LOW 1.9 - 5.8% - CF: moderate 8.0 - 19.3% - NFE: HIGH 56.7 - 73.2% - EE: Moderate for plant material 1 - 4.9% except sweet gallberries high 10.8% - Ash: moderate 1 - 7.6% - Ca & P: Ca low-high (0.13 - 0.71%), P low 0.06 - 0.1%, Ca:P poor - CP, Ca, P (LOW) - Ca & P usually LOW in fleshy fruits - apples, blueberries, cherries, grapes, prickly pear (0.007 - 0.028%) - Ca:P poor
87
What is the key problem with frugivore diets?
- Composition of food is VARIABLE and they MUST eat variety
88
what do mycophages eat? How is the composition of this food measured?
- fungi - Hypogenous/underground fungi - % DM
89
What is the composition of Fungi?
- very low DM%, bulky, ~73.5% water - HIGH CP, 21.5% - BUT 60-79% of CP is either unavailable in cell walls or indigestible spored or present as non-protein N - LOW Ca 0.09% - LOW Na 0.030% - GE 5.0 kcal/g
90
What mycophage animals eat hypogenous fungi?
- long-nosed potoroo, marsupial (fore gut fermenter) - red-backed vole, eutherian mammal (caecum fermenter)
91
Compare the digestibility % of a fore-gut fermenter with the caecum fermenter.
- DM & GE: Higher in foregut - CP digestibility quite low in both, lower in caecum - NDF, vole may grind food better when eating so caecum fermenter is higher
92
What do the fungal cell walls contain? are they available all year round or seasonally?
- Seasonally available - Fungal cell walls contain hemicellulose, cellulose and may contain chitin
93
What do Lichenophages eat?
- Lichens
94
What animals are included in the Lichenophage type?
- mountain goats, black-tailed deer, Tunnan snub-nosed monkey, flying squirrel, caribou/reindeer
95
What is the digestibility of CP in the lichenophage diet?
- Low - 2-3% CP - poor protein in diet
96
What are the limiting factors to the lichenophage diet? (7)
- protein (metabolism and conservation), Ca, P, Sodium, Toxins, antinutrients, Foraging Theory
97
What is the digestibility of Ca and P and Ca:P in the lichenophage diet?
- 0.31% Ca LOW - 0.36% P - Ca:P 0.9:1 OKAY
98
How do lichenophages "deal with" the limiting factor of salt in their diet?
- salt licks
99
What is the first possible reason for salt lick use by herivores and birds?
- Involves soil ingestion - Geophagia - Supplies adequate Na and Mg - Better than non-lick areas: roadside, old field, woodland
100
What is a "natural salt lick area"?
- Area where animals are observed to lick the ground and ingest soil/minerals
101
How would you investigate the reasons for salt lick use? Which salts were most successful?
- Use water containing Na salts to soak wooden stakes in - Salts used: NaCl, CaI, NaHCO3
102
In an experiment looking into salt lick use, what animals were observed and what were they doing?
- rabbits, fox squirrels, groundhogs, white-tailed deer - observed drinking dilute Na solution - observed chewing/licking the wooden stakes which had been soaked in NaCl, NaI, NaHCO3 - ignored the stakes soaked in Ma, Ca, K salts
103
What interesting observations have been made regarding mineral intake and salt licks?
- porcupines - damaging wooden buildings then the wood had been soaked in urine containing salt Na - Mountain goats in olympic national park have been observed eagerly eating table salt offered by visitors - NaCl has been used as a very effective bait in trapping white-tailed deer in the Adirondack Mountains in spring & summer (in winter food was the most effective bait)
104
What is the second reason for using salt licks? what is the importance os this aspect of the diet?
- to counter balance rumen acidosis - Healthy rumen/reticulum pH is 5.5-7.0 - pH may decrease -\> 4.0 with high starch in diet a: buffering pH b: physical protection of epithelium
105
What was the third reason for using salt licks?
- Protection against plant toxins - Adsorption of toxins, onto soil particles - Epithelium protection
106
what is the fourth reason for using salt licks?
- Communication (grinding and triturating) of food particles - Eg. pangolin (anteater, with no teeth), ingest sand to abrade ant exoskeletons
107
What is the fifth reason to use a salt lick? give and example
- microbial inoculation - eg. young ruminants, foregut fermenters
108
What is the sixth reason for using a salt lick?
- to fill stomach to dispel hunger during starvation
109
What is the 7th reason for using a salt lick? give example
Deprived appetite, pica - eg. eating a non-food item - may be difficult to tell when substance eaten has a valid nutritional use
110
What are toxins, antinutrients and antimetabolites?
- plant protective and defensive agents - substances that physically prevent digestive enzymes from reaching the digestible carbohydrates, protein and lipids - substances that interfere with digestion, nervous system function, growth and reproduction AND/OR taste bitter or smell bad
111
List the 4 types of physically protective antinutrients.
- Lignin, Cutin, Silica/Quartz, Suberin
112
Explain the composition of lignin.
- Xylem are dead, end walls disintegrate leaving hollow tubes & side walls are strengthened with rings or spirals of lignin - transport water, minerals from soil & support the plant/tree
113
How is lignin digested?
- not digested by animal, bird or bacterial enzymes or acid hydrolysis in the gastric stomach (abomasum, proventriculus) - lignin is the main protector of digestible cell wall carbohydrates - lignin can be broken down by certain fungi - eg. bracket fungi on tres
114
What is the composition and function of Cutin?
- found as the structural component of the plant cuticle @ the plan surface - reduces water loss - prevents entry my microbes
115
What is the composition and digestibility of Suberin (& cutin)?
- found between the cell wall and cell contents - cork cells/outer layer of tree bark, wound repair, around some roots - cutin & suberin very poorly digested
116
What is the composition and digestibility of silica/quartz?
- found in grasses, sedges, ferns, horsetails - not usually in dicotyledons - Si, 3-5% DM in grasses - hard gritty mineral - reduce cell wall digestibility - increase tooth abrasion - may result in formation of urinary calculi
117
Describe the composition and function of secondary plant components that are antinutrients/antimetabolites.
- Have few/no primary metabolic function within the plant - Anti-herbivory compounds - most act against all consumers (broad spectrum): against mammals, birds, reptiles, amphibians, fish, invertebrates - A few are selective
118
Which secondary plant compounds are selective?
- Pyrethrins (from chrysanthemum flowers) - highly toxic to insects - low toxicity to mammals
119
How do secondary plant compounds act within the plants that produce them? How do the plants deal with them?
- usually toxic to the plants that produce them - must be isolated within the plant OR must be stored in an inactive form that becomes active when the plant material is consumed
120
How do primary consumers deal with secondary plant components?
- evolve new biochemical detoxification pathways - plants constantly evolve new defence compounds OR - avoid - foregut bacteria - metabolic breakdown
121
How are secondary plant compounds digested?
- detoxified in the GIT bacteria - ruminants and other foregut fermenters have an advantage over hind-gut fermenters, detoxification early in passage through the GIT
122
Can some secondary plant compounds be beneficial? How?
- Yes, under certain circumstances - tannins may bind to viral, bacterial, fungal pathogens in the GIT and reduce infection - 6-MBOA stimulates reproduction in many herbivorous rodents, male and female. - In high concentrations in sprouting grasses (recently found in bamboo shoots) absence of bamboo shoots in diet of captive panda has been associated with reproductive failure.
123
What is the relationship between secondary plant compounds and unripe fruit?
in fruits that must be eaten first to disperse seed, as the fruit ripens: - levels of 2ndary plant compounds decrease in the fruit and increase in the seed - and NOT all fruit us for eating
124
What are the 11 groups of toxins, antinutrients and antimetabolites?
- Selenium - Cardiac glycosides - Coumarins - Goitrogens - Thiaminase - Oxalic Acid - Phytic Acid - Cyanogenic Glycosides - Terpenoids - Alkaloids - Soluble phenolics
125
What are soluble phenolics? give some examples.
- isoflavanoids, coumestans, phytoestrogens: proteins in \>200 plant species: - soybeans, some clovers may cause sterility, abortions, liver damage - Captive mink: infertility associated with soybeed feeds - Captive cheetahs: in US only 9-12% females produce live cubs compared to in S. africa where 60-80% (associated with soybean feed in US)
126
What is the distribution of tannins among plants? What is their main characteristic?
- 17% non-woody annuals - 14% herbaceous perennials - 79% deciduous woody perennials - 87% evergreen woody perennials - Bitter taste (tea or red wine)
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What is the difference between soluble and insoluble tannins?
- soluble tannins bind proteins dependant on pH - insoluble tannins may be more effective
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How do tannins affect digestibility?
- by binding to dietary protein, digestive enzymes - eg. tanning of leather eg. Steenbok antelope (7-16kg); 1% tannin added to the diet - protein and energy digestion decreased 5% - fibre digestion decreased 10%
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How do animals adapt to consuming tannin?
- secretion of tannin; binds proteins in the saliva - eg. bears, moose, mule deer - eg. rats produce proline rich ppt in saliva, these bind tannins - May also bind to Fe (excess Fe in black rhinos not fed enough browse.
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What are alkaloids?
- toxins, nitrogenous compounds - in ~20% of flowering plants - ex. micotine from tobacco, morphine from poppies, strychnine in seeds of NUX vomica
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What is an example of an alkaloid in poison hemlock?
- Conine - quail eat hemlock seeds, build up high levels of conine in tissues, quail unaffected - humans/animals eating quail are poisoned
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What are other examples of alkaloids in plants?
- tomatine in tomato plants - Solanine in unripe potatoes & potato shoots - Atropine (belladonna) in deadly nightshade - cocaine in leaves of coca plant - Ricinine in castor plant seeds - Caffeine in coffee plant and beans; higher concentration in young tender leaves, young soft coffee beans
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Over what time frame do alkaloids vary in concentration? give an example.
- throughout the day - Opium sap from poppies is the highest morphine concentration between 9-10am and is collected at that time - BUT opium poppy is the source of medical morphine and codeine
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What are terpenoids?
- lipids - some are essential oils (aromatic, herbs, etc.) antimicrobial, will not affect gut bacteria if introduced gradually - new shoots and buds have lower concentrations of essential oils
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Give examples of Terpenoids.
- volatile, aromatic oils of sagebush, evergreens - Pyrethrin from chrysanthemums (insecticide) - Eucalyptol from eucalyptus - oils in the peel of citrus fruits - also vitamins A, E and K
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What are Cyanogenic glycosides?
- toxic polysaccharides - inactive cyanogenic glycosides found in 1000+ species of plant - When plant material is chewed, the glycosidase enzyme comes into contact with the inactive cyanogenic glycoside and hydrogen cyanide is released
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Give example of cyanogenic glycosides:
- linamarin in linseed, java beans, cassava - vicianin in vetch seeds - amygdalin in bitter almonds, kernels of peach, cherries, plums, apples - lotaustralin in trefoil, white clover
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What is phytic acid?
- found in seeds, P only available to fore-gut fermenters and ruminants - if phytic acid is not broken down by gut bacteria, it will bind Zn and Ca making them unavailable - eg. low phytate rice gene silencing
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What is Oxalic acid?
- found in leaves (rhubarb) NOT in stems - broken down by gut bacteria in for-gut fermenters, ruminants - if OA is not broken down by gut bacteria it will bind Za and Ca making them unavailable - Is also a toxin
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What is thiaminase?
- breaks down thiamin (vitamin B1) - found in an inactive form in some live fish & shell fish - after death thiaminase is activated and destroys thiamin - may be a problem if wildlife eat dead fish in quantity, thiamin deficiency - found in bracken fern (except young shoots) and horsetail - Thiaminase broken down by bacteria in foregut fermenters and ruminants - if too much is eaten it becomes a problem
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What are goitrogens?
- nitrates, thiocyanates - block uptake of iodine = enlarged thyroid, goiter - found in cabbage, kale, soybeans - goitrogens broken down by bacteria in foregut fermenters, ruminants - in non-ruminants/foregut fermenters problems may only occur is iodine deficiency is pre-existing, or very large quantities are eaten for a considerable amount of time (diet variability)
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What are coumarins?
- vitamin K inhibitors - Dicoumarol, found in moldy sweet clover
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What are cardiac glycosides?
- toxin - eg. digitalis, in foxgloves, but is used to treat heart problems as medication "digoxin"
144
What is selenium?
- Se substituted for S in methionine and cysteine (malfunctioning selenozymes) - accumulator plants, contain toxic concentrations of SE when grown on High-selenium soils - eg. milk vetch, poison vetch, woody aster (accumulator plants) - normally unpalatable to herbivores, but may be eaten under starvation conditions - when accumulator plants die they release high Se into soil and non-accumulator plants may then become toxic
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What is the main source of poisoning for white-tailed deer?
- solanum sp. (potato, tomato, nightshades) - acorns
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What is the main source of poisoning for Mule deer?
- narrow-leaved milkweed, acorns
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What is the main source of poisoning for Koala?
- manna gum = a eucalyptus
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What is the main source of poisoning for Sika deer?
- pine needles & twigs
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What is the main source of poisoning for Elk?
- locoweed
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What is the main source of poisoning for Pronghorn antelope?
- chokecherry, tarbus
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How do animals deal with plant toxins?
Selectivity, dilution, detoxification, bind toxins
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Explain how animals use selectivity to deal with toxins.
- eat new, young vegetative plant material - Toxins may still be in low concentrations - lignin, essential oils of sagebush and evergreens - Caffeine in higher concentration in young
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How do animals use dilution to deal with plant toxins?
- eat a variety of plant foods - any toxins will be diluted in overall diet
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How do animals used detoxification to deal with plant toxins?
a: foregut fermenters, ruminants, GIT, bacteria break down many toxins - introduce new diet items slowly, if toxins present bacterial population have time to adapt b: tissue-level detoxification - by enzymes in the liver, first organ the blood reached after toxins are absorbed - eg. in koala ~1/3 glucose used in detox, glucuronic acid formed and excreted in urine
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Explain how binding toxins helps animals to deal with them.
- eat clay/soil particles which bind toxins
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- What is the protein, EAA, digestibility, minerals, and vitamin content of fish?
- Soft tissue is high in protein, highly digestible
- Balance of EAAs similar to requirements (vertebrates)
- they are a good source of minerals and vitamins (vertebrates)
- LOW in calcium, IF prey is not eaten whole
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What is the composition of nutrient dense fruits? Give 2 examples of these types of fruit.
- datesm avacados, mistletoe
- low water content
- high lipid 10-70% DM
- sometimes protein 5-20% DM
- low carbohydrates
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How is chitin dealt with in insects with a low chitin content?
- select insects with a low chitin content
- Remove high-chitin part of the exoskeleton before ingestion (wings, tibia, 50% chitin, of grasshoppers removed by grasshopper sparrows)
- Crush the insect with beak or teeth, extract soft tissues & discard exoskeleton
- eat insects whole then egest exoskeletons (kestrel, swallows, flycatchers)
- Produce chitinase enzymes, at least partially digest chitin, energy value of chitin usually low
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What are the different strategies in digestive efficiency of NFE between ruminants & non-ruminants?
NFE: - somewhat higher in non-ruminants - cell contents may be digested by pre-gastric bacteria in ruminants (less efficient anaerobic fermentation cf gastric digestion)
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What are the different strategies in digestive efficiency of DE between ruminants & non-ruminants?
DE: - lower in both ruminants & non-ruminants when compared to carnivores - energy density (GE) of vegetative plant food is less than that of animal flesh & adipose tissue
161
What is the Ca & P composition of weed seeds and cultivated grains of the herbivore diet?
- Weed seeds, Ca good (except buckwheat) P adequate
- Need 0.5%DM Ca and minimum Ca:P 1:1
- Cultivated grains: Ca LOW and Ca:P poor
P - some P seeds and grains is present as phytate, poorly digested
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Some P in seeds and grains is present as phytate and is poorly digested. How is this managed in grainivores?
- phytic acid = inositol hexaphosphate - phytases in the seed release P for germination - Animals/birds have little phytase - P in phytate will be unavailable - ruminants/foregut fermenters, microbes have phytases, make P available to animal Na: - not given in analysis, may be LOW
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What species digest autoenzymtically?
* Frugivores
* Grainivores
* carnivores & Piscivores
* insectivores
* Micro faunivores
* Nectarivores
*
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What do nectarivores feed their young? What so they also eat in order to fulfil their amino acid requirements?
- insects / other invertebrates
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In grainivores, the balance of amino acids may be variable or poor. Give 1 example of food where the imbalance is due to missing AAs and 1 where the imbalance is due to excess.
* Legumes- high in lysine
* Some seeds - low in methionine and lysine
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In grainivores, the oil content is variable. Give 1 example of food that has low lipids and 1 example with high lipids.
* oil seeds, sunflowers, safflowers
* Grass seeds
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Grainivores ingest moderate levels of P, explain why ~60-70% of this may be unavailable.
* In the form of phytate
* Gut microbes can break down phytate and release P
* Phytase enzyme
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What can be found in some wild seeds that may reduce digestibility?
- Toxins and antinutrients
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What do frugivores feed to thir young? why?
- insects to meet the protein requirements for growth
170
At what ratio should Ca:P be?
1:1 - 2:1
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true or false. Removing the bones before analysis will give a better nutritional profile of the animal.
False. Carnivores usually eat some of the bones or bone marrow.
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True or false. Removing the GIT from the animal does not affect the nutritional profile of the carcass?
False. GIT is usually eaten although contents may be left, adipose tissue around GIT may be eaten
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How does removing the bones and hide affect the CP analysis of a carcass?
- bones contain protein as collagen & hair/feathers are high in protein as keratin but vary in digestibilitiy
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What is the most variable component of animal food analysis?
- Ether extract
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How are animals often analysed for EE? What problem could this pose?
- carcasses from kills
- predators will often kill young of emaciated/ill animals (the weakest) and these may have less fat or a different composition
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Why do lab mice often have a higher fat content?
- no thermoregulation, activity hunting for food, and no activity escaping predators
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What are the two components of CF? where are these found in plants and animals?
- ADF and NDF
- plant cell walls and animal GIT contents
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What is the lease USEFUL value of a composition analysis? What plant and animal components are included in this value?
- NFE
- animal tissues: glycogen
- plant tissues (GIT contents): sugars, starch, pectin, hemicellulose, cellulose
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How does the gross energy of the carnivore diet change with season? When is it highest?
- Seasonally; highest in late summer early fall
180
How is digestibility measured in mammals? in birds? how is metabolizability meaured?
181
True or false. removing the GIT, bones and hide affect the lipid content of the analysis.
False.
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183
What is the ME of bird (GE)? What is the DE of mammals (GE)? What is the ME of mammals (GE and DM)?
~75% of GE in birds
~90% of GE
~ 82% of GE ( ~91% of DM)
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In the insecitvore and nicrofaunivore diet, what invertebrate is an exception to the Ca:P, and Ca? Why?
Earthworm because of soil in their gut.
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how do the effects fo climate affect the variability of forage and browse?
- High temperatures quality may decrease quickly
- Low rainfall may remay reduce growth & quality; may decrese quickly
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In the herbivore diet is crude protein seasonal? When is it higher & lower?
Lower from late summer to early spring, higher spring to summer
187
What is the relationship between biomass and quality in the peak of the summer?
- biomass is low when quality is high
188
How does CF fluctuate seasonally?
- Decreases from mid summer to late winter
189
How does DM digestibility vary seasonally? Why?
Drops at end of summer
- More fibre - increase cellulose and lignin
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What is included in NDF? what is this a measure of?
- cellulose, hemicelluose, lignin & plant cell wall
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What is ADF? What is this correlated with?
- cellulose and lignin and digestibility
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