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Lecture 8

ANSC 3180 Lecture Notes - Lecture 8: Altricial, Puggle, Crop MilkPremium

12 pages99 viewsWinter 2017

Department
Animal Science
Course Code
ANSC 3180
Professor
Esther Finegan
Lecture
8

This preview shows pages 1-3. to view the full 12 pages of the document.
Sperm
Egg (mammal and bird)
Foetus
Enlarged reproductive organs (testes, ovary/oviduct, uterus, mammary glands)
Milk
Heat for egg incubation
Territorial establishment and defense / courtship
Nest/burrow construction
Energy and nutrients are required for:
Testicular growth -minimal energy and protein requirements
Sperm productions -minimal energy and protein requirements
Ex. Manes in lions; horns/antlers on cattle/deer -->protein/calcium requirements
Males:
Ovary and oviduct growth -minimal energy and protein requirements
Water content decreases; protein, fat and mineral content increases
Foetal growth: ~80% growth occurs during the last 40% of gestation
!
Gravid uterus growth (uterus + foetus)
Mammary growth
Total energy expenditure by lactating mammals: 4-7 x BMR
!
Milk is produced by all mammals (eutherians), marsupials and
monotremes
!
Lactation
Protein -12.5%
!
Ash (mineral) -2.7% (mostly in skeleton)
!
Seals: ~9-12% fat (cold ambient temperatures; short lactation)
Guinea pig: ~10% fat -used immediately
Human: ~16% fat
Fat - 2.1% …except:
!
Body composition (averages) of the mammalian neonate:
Mouse (altricial: naked, blind, immobile)
!
White-tailed deer (precocial: pelage/plumage, sighted, mobile)
!
Low fat of most neonates (~2%)-both precocial and altricial species
17-35% higher than non-pregnant
!
Daily expenditure of pregnant mammals: 2.7-3.1 x BMR
Females:
Energy Reproduction in Mammals:
*monotremes -egg laying mammals (young echidna -puggle)
Fed as only food for first 3 days and then is gradually mixed with other
food (production for 3-4 weeks)
!
Under control of prolactin
!
Pigeons and doves (both parents) produce 'crop milk' (sloughed, crop-wall
epithelial cells) rich in fat (35%) and protein (60%)
Male emperor penguins: feed newly hatched chicks a secretion from oesophageal
epithelial cells
Greater flamingoes: feed hatchlings with a secretion from oesophageal mucous
glands
'Lactation' -oesophageal/crop secretions fed by a few bird species to hatchings
Energy Reproduction in Birds:
To the foetus only in utero (primates, guinea pigs, rabbits)1)
To the foetus both in utero and from colostrum (rats & mice -16-20days;
cats, dogs)
2)
Have heavy barrier in placenta -require milk for disease
control
!
Will appear in blood rapidly
!
Ungulates (24-36 hrs): hooved mammals, perissodactyls (equids,
tapirs, rhinos), and artiodactyls (pigs, hippos, camelids, ruminants)
Marsupials (macropods: 170-200 days)
Mink (8 days)
To the neonate only in colostrum (for as long as intestine is permeable to
immunoglobulins)
3)
Maternal immunoglobulins may be passed:
Colostrum -first milk produced each lactation; may contain IgG immunoglobulins to
provide passive immunity to the neonate
Water, minerals, protein (e.g. casein), fat, carbohydrates (lactose in
eutherian mammals)
!
Composition:
Equids/black rhino: 90-91% water
!
Seals: 30-48% water
!
Concentration (dilute -very concentrated)
Equids/black rhino/ primates: <2% protein
!
Some seals/lagomorphs: 10-15% protein
!
Protein Content:
Equids/black rhino/primates: <2% fat
!
Seals: 39-61%
!
Fat Content:
Equids/black rhino/ primates: 6-8% sugar
!
Seals: <1% sugar
!
Sugar Content:
Equids/black rhino/primates: <1kcal/g
!
Seals: 4-6 kcal/g
!
Energy Content:
Dilute (76-83% water) --> Concentrated (65-74% water)
Low fat (2-5%) --> moderate fat (13-16%)
Low protein (3-6%) --> moderate protein (7-15%)
High sugar (6-11%) --> moderate sugar (2-5%)
Low energy (<1kcal/g) --> higher energy content (1.5-2 kcal/g)
Period 1 (young is confined to pouch )--> Period 2 (young can leave
pouch)
!
Marsupial Milk:
Concentrated, high fat, high energy milk
!
May compensate for high heat loss by neonates in cold environment
!
Hooded seal: short lactation (~4 days), grows 22-44 kg/4 days
!
Seals:
Mainly plamitic (16:0), oleic (18:1)
!
Lagomorphs, elephants -mainly capric (10:0)
!
Seals -mainly long chain unsaturated FA (18:3, some 18:1, some palmitic)
!
Fatty Acid Composition:
Usually highest in colostrum
!
Taurine -essential for most mammalian neonates (especially carnivores)
Mule deer -yound nurses 2-10x per day
Single fawn drinks 150-200 g/nursing bout
'hiders' -mother returns to 'hidden' neonate several times a day to nurse
!
Mountain goat -nurses ~40x /day
Single young drinks ~50g/nursing bout
'followers' -neonate follows mother and nurses more frequently than
hiders
!
Intake by Neonates:
Milk:
Mammalian Reproduction:
Testicular growth -0.5% BMR, 3.5% maintenance protein
Sperm production -0.8% BMR
Males:
Ovary and oviduct (produce albumen, shell) -growth is 4% BMR, 28%
maintenance protein
Number varies with age of female (young females may lay
fewer eggs)
!
Number varies with food availability (fewer eggs may be laid
when food is scarce)
!
Egg number:
Size inversely proportional to BW (smaller birds lay larger
eggs relative to BW)
!
Size varies with age of female (young females lay smaller
eggs)
!
Size varies with availability of foods (eggs may be smaller
when food is scarce)
!
Egg Size:
Depends on stage of development of embryo at hatching
!
Young show a marked delay in beocming
independent
!
Young often hatched/born naked, blind and
immbobile
!
Ex. Crows, robins. Starlings, rat, mouse
!
Altricial species:
Young show high degree of independent activity
from hatching/birth
!
Young usually hatched/born with plumage/pelage,
sighted and mobile
!
Ex. Chickens, ducks, white-tailed deer
!
Precocial species:
'nest loving'
!
Young remain in nest being fed for a prolonged
period after hatching/birth
!
Nidicolous species:
'nest fleeing'
!
Young leave the nest almost immediately after
hatching, and start searching for food
!
Nidifugous species:
Altricial -precocial (nidicolous -nidifugous)
!
~40% fresh weight egg -precocial (ducks, geese)
~20% fresh weight egg -altricial (crows, robins)
Yolk size is larger in precocial species than altricial to support
more advanced development before hatching
!
Yolk synthesis (in ovary) takes 4-26 days, albumen synthesis
takes 1-2 days as the ova passes through oviduct
!
Albumin -no lipids, protein (7.1-10.1%)
Yolk contains lipids and protein (13.5-18.5%)
!
Yolk lipid content in higher (34.7-38.3%) in precocial species
than in altricial (23.2-28.4%)
!
1.2:1 -ducks and geese (precocial)
3.6:1 -crows and blackbirds (altricial)
4.9:1 -starlings (altricial)
Albumen/yolk ratio:
!
Egg Composition:
Requirement depends on egg number, egg size, egg composition and
laying interval
!
Egg production
29% BMR, 72% maintenance protein
Hawks, owls (semi-altricial) lay 1 medium sized egg per 3-4 days
!
200+% BMR, 220% maintenance protein
Waterfowl (precocial) lay 1 large, high-energy egg per day
!
Fat deposition prior to egg laying
Mobilizing body fat and protein while laying
Increasing food intake
Changing diet to highly nutritious foods (e.g. Insects)
Meeting requirements for egg laying
!
Egg Laying: daily energy and protein requirements
Heat is needed to start embryonic development in the egg and allow it to
continue
!
Clutch size
Insulation provided by nest
BW of incubating adult bird
Ambient air temperature
Heat required depends on:
!
Normal heat loss through the brood patch is sufficient if ambient
temperature is in the birds thermoneutral zone
!
As incubation progresses, the developing embryo contributes an increasing
heat amount
!
Adult incubating bird has less time to feed
!
Penguins, geese -one parent may do all incubating and rely on fat
deposited before nesting
Canada geese, common eider ducks -loose ~45% BW between
arriving at nesting group and eggs hatching
Some species, both parents share incubation or non-incubating parent may
bring food for the incubator
!
Incubation
Females:
Avian Reproduction:
*Seals are born without lactase
--> lactose-intolerant
*Marsupials can
produce milk with
different content in
each nipple if they
have two young in
different periods
Energy: Reproduction
Friday,*February*10,*2017
12:24*PM
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Unlock to view full version

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Sperm
Egg (mammal and bird)
Foetus
Enlarged reproductive organs (testes, ovary/oviduct, uterus, mammary glands)
Milk
Heat for egg incubation
Territorial establishment and defense / courtship
Nest/burrow construction
Searching for food for young
Energy and nutrients are required for:
Testicular growth -minimal energy and protein requirements
Sperm productions -minimal energy and protein requirements
Ex. Manes in lions; horns/antlers on cattle/deer -->protein/calcium requirements
Males:
Ovary and oviduct growth -minimal energy and protein requirements
Water content decreases; protein, fat and mineral content increases
Foetal growth: ~80% growth occurs during the last 40% of gestation
!
Gravid uterus growth (uterus + foetus)
Mammary growth
Total energy expenditure by lactating mammals: 4-7 x BMR
!
Milk is produced by all mammals (eutherians), marsupials and
monotremes
!
Lactation
Protein -12.5%
!
Ash (mineral) -2.7% (mostly in skeleton)
!
Seals: ~9-12% fat (cold ambient temperatures; short lactation)
Guinea pig: ~10% fat -used immediately
Human: ~16% fat
Fat - 2.1% …except:
!
Body composition (averages) of the mammalian neonate:
Mouse (altricial: naked, blind, immobile)
!
White-tailed deer (precocial: pelage/plumage, sighted, mobile)
!
Low fat of most neonates (~2%)-both precocial and altricial species
17-35% higher than non-pregnant
!
Daily expenditure of pregnant mammals: 2.7-3.1 x BMR
Females:
Energy Reproduction in Mammals:
*monotremes -egg laying mammals (young echidna -puggle)
Fed as only food for first 3 days and then is gradually mixed with other
food (production for 3-4 weeks)
!
Under control of prolactin
!
Pigeons and doves (both parents) produce 'crop milk' (sloughed, crop-wall
epithelial cells) rich in fat (35%) and protein (60%)
Male emperor penguins: feed newly hatched chicks a secretion from oesophageal
epithelial cells
Greater flamingoes: feed hatchlings with a secretion from oesophageal mucous
glands
'Lactation' -oesophageal/crop secretions fed by a few bird species to hatchings
Energy Reproduction in Birds:
To the foetus only in utero (primates, guinea pigs, rabbits)1)
To the foetus both in utero and from colostrum (rats & mice -16-20days;
cats, dogs)
2)
Have heavy barrier in placenta -require milk for disease
control
!
Will appear in blood rapidly
!
Ungulates (24-36 hrs): hooved mammals, perissodactyls (equids,
tapirs, rhinos), and artiodactyls (pigs, hippos, camelids, ruminants)
Marsupials (macropods: 170-200 days)
Mink (8 days)
To the neonate only in colostrum (for as long as intestine is permeable to
immunoglobulins)
3)
Maternal immunoglobulins may be passed:
Colostrum -first milk produced each lactation; may contain IgG immunoglobulins to
provide passive immunity to the neonate
Water, minerals, protein (e.g. casein), fat, carbohydrates (lactose in
eutherian mammals)
!
Composition:
Equids/black rhino: 90-91% water
!
Seals: 30-48% water
!
Concentration (dilute -very concentrated)
Equids/black rhino/ primates: <2% protein
!
Some seals/lagomorphs: 10-15% protein
!
Protein Content:
Equids/black rhino/primates: <2% fat
!
Seals: 39-61%
!
Fat Content:
Equids/black rhino/ primates: 6-8% sugar
!
Seals: <1% sugar
!
Sugar Content:
Equids/black rhino/primates: <1kcal/g
!
Seals: 4-6 kcal/g
!
Energy Content:
Dilute (76-83% water) --> Concentrated (65-74% water)
Low fat (2-5%) --> moderate fat (13-16%)
Low protein (3-6%) --> moderate protein (7-15%)
High sugar (6-11%) --> moderate sugar (2-5%)
Low energy (<1kcal/g) --> higher energy content (1.5-2 kcal/g)
Period 1 (young is confined to pouch )--> Period 2 (young can leave
pouch)
!
Marsupial Milk:
Concentrated, high fat, high energy milk
!
May compensate for high heat loss by neonates in cold environment
!
Hooded seal: short lactation (~4 days), grows 22-44 kg/4 days
!
Seals:
Mainly plamitic (16:0), oleic (18:1)
!
Lagomorphs, elephants -mainly capric (10:0)
!
Seals -mainly long chain unsaturated FA (18:3, some 18:1, some palmitic)
!
Fatty Acid Composition:
Usually highest in colostrum
!
Taurine -essential for most mammalian neonates (especially carnivores)
Mule deer -yound nurses 2-10x per day
Single fawn drinks 150-200 g/nursing bout
'hiders' -mother returns to 'hidden' neonate several times a day to nurse
!
Mountain goat -nurses ~40x /day
Single young drinks ~50g/nursing bout
'followers' -neonate follows mother and nurses more frequently than
hiders
!
Intake by Neonates:
Milk:
Mammalian Reproduction:
Testicular growth -0.5% BMR, 3.5% maintenance protein
Sperm production -0.8% BMR
Males:
Ovary and oviduct (produce albumen, shell) -growth is 4% BMR, 28%
maintenance protein
Number varies with age of female (young females may lay
fewer eggs)
!
Number varies with food availability (fewer eggs may be laid
when food is scarce)
!
Egg number:
Size inversely proportional to BW (smaller birds lay larger
eggs relative to BW)
!
Size varies with age of female (young females lay smaller
eggs)
!
Size varies with availability of foods (eggs may be smaller
when food is scarce)
!
Egg Size:
Depends on stage of development of embryo at hatching
!
Young show a marked delay in beocming
independent
!
Young often hatched/born naked, blind and
immbobile
!
Ex. Crows, robins. Starlings, rat, mouse
!
Altricial species:
Young show high degree of independent activity
from hatching/birth
!
Young usually hatched/born with plumage/pelage,
sighted and mobile
!
Ex. Chickens, ducks, white-tailed deer
!
Precocial species:
'nest loving'
!
Young remain in nest being fed for a prolonged
period after hatching/birth
!
Nidicolous species:
'nest fleeing'
!
Young leave the nest almost immediately after
hatching, and start searching for food
!
Nidifugous species:
Altricial -precocial (nidicolous -nidifugous)
!
~40% fresh weight egg -precocial (ducks, geese)
~20% fresh weight egg -altricial (crows, robins)
Yolk size is larger in precocial species than altricial to support
more advanced development before hatching
!
Yolk synthesis (in ovary) takes 4-26 days, albumen synthesis
takes 1-2 days as the ova passes through oviduct
!
Albumin -no lipids, protein (7.1-10.1%)
Yolk contains lipids and protein (13.5-18.5%)
!
Yolk lipid content in higher (34.7-38.3%) in precocial species
than in altricial (23.2-28.4%)
!
1.2:1 -ducks and geese (precocial)
3.6:1 -crows and blackbirds (altricial)
4.9:1 -starlings (altricial)
Albumen/yolk ratio:
!
Egg Composition:
Requirement depends on egg number, egg size, egg composition and
laying interval
!
Egg production
29% BMR, 72% maintenance protein
Hawks, owls (semi-altricial) lay 1 medium sized egg per 3-4 days
!
200+% BMR, 220% maintenance protein
Waterfowl (precocial) lay 1 large, high-energy egg per day
!
Fat deposition prior to egg laying
Mobilizing body fat and protein while laying
Increasing food intake
Changing diet to highly nutritious foods (e.g. Insects)
Meeting requirements for egg laying
!
Egg Laying: daily energy and protein requirements
Heat is needed to start embryonic development in the egg and allow it to
continue
!
Clutch size
Insulation provided by nest
BW of incubating adult bird
Ambient air temperature
Heat required depends on:
!
Normal heat loss through the brood patch is sufficient if ambient
temperature is in the birds thermoneutral zone
!
As incubation progresses, the developing embryo contributes an increasing
heat amount
!
Adult incubating bird has less time to feed
!
Penguins, geese -one parent may do all incubating and rely on fat
deposited before nesting
Canada geese, common eider ducks -loose ~45% BW between
arriving at nesting group and eggs hatching
Some species, both parents share incubation or non-incubating parent may
bring food for the incubator
!
Incubation
Females:
Avian Reproduction:
*Seals are born without lactase
--> lactose-intolerant
*Marsupials can
produce milk with
different content in
each nipple if they
have two young in
different periods
Energy: Reproduction
Friday,*February*10,*2017 12:24*PM
You're Reading a Preview

Unlock to view full version

Subscribers Only

Only half of the first page are available for preview. Some parts have been intentionally blurred.

Subscribers Only
Sperm
Egg (mammal and bird)
Foetus
Enlarged reproductive organs (testes, ovary/oviduct, uterus, mammary glands)
Milk
Heat for egg incubation
Territorial establishment and defense / courtship
Nest/burrow construction
Searching for food for young
Energy and nutrients are required for:
Testicular growth -minimal energy and protein requirements
Sperm productions -minimal energy and protein requirements
Ex. Manes in lions; horns/antlers on cattle/deer -->protein/calcium requirements
Males:
Ovary and oviduct growth -minimal energy and protein requirements
Water content decreases; protein, fat and mineral content increases
Foetal growth: ~80% growth occurs during the last 40% of gestation
!
Gravid uterus growth (uterus + foetus)
Mammary growth
Total energy expenditure by lactating mammals: 4-7 x BMR
!
Milk is produced by all mammals (eutherians), marsupials and
monotremes
!
Lactation
Protein -12.5%
!
Ash (mineral) -2.7% (mostly in skeleton)
!
Seals: ~9-12% fat (cold ambient temperatures; short lactation)
Guinea pig: ~10% fat -used immediately
Human: ~16% fat
Fat - 2.1% …except:
!
Body composition (averages) of the mammalian neonate:
Mouse (altricial: naked, blind, immobile)
!
White-tailed deer (precocial: pelage/plumage, sighted, mobile)
!
Low fat of most neonates (~2%)-both precocial and altricial species
17-35% higher than non-pregnant
!
Daily expenditure of pregnant mammals: 2.7-3.1 x BMR
Females:
Energy Reproduction in Mammals:
*monotremes -egg laying mammals (young echidna -puggle)
Fed as only food for first 3 days and then is gradually mixed with other
food (production for 3-4 weeks)
!
Under control of prolactin
!
Pigeons and doves (both parents) produce 'crop milk' (sloughed, crop-wall
epithelial cells) rich in fat (35%) and protein (60%)
Male emperor penguins: feed newly hatched chicks a secretion from oesophageal
epithelial cells
Greater flamingoes: feed hatchlings with a secretion from oesophageal mucous
glands
'Lactation' -oesophageal/crop secretions fed by a few bird species to hatchings
Energy Reproduction in Birds:
To the foetus only in utero (primates, guinea pigs, rabbits)
1)
To the foetus both in utero and from colostrum (rats & mice -16-20days;
cats, dogs)
2)
Have heavy barrier in placenta -require milk for disease
control
!
Will appear in blood rapidly
!
Ungulates (24-36 hrs): hooved mammals, perissodactyls (equids,
tapirs, rhinos), and artiodactyls (pigs, hippos, camelids, ruminants)
Marsupials (macropods: 170-200 days)
Mink (8 days)
To the neonate only in colostrum (for as long as intestine is permeable to
immunoglobulins)
3)
Maternal immunoglobulins may be passed:
Colostrum -first milk produced each lactation; may contain IgG immunoglobulins to
provide passive immunity to the neonate
Water, minerals, protein (e.g. casein), fat, carbohydrates (lactose in
eutherian mammals)
!
Composition:
Equids/black rhino: 90-91% water
!
Seals: 30-48% water
!
Concentration (dilute -very concentrated)
Equids/black rhino/ primates: <2% protein
!
Some seals/lagomorphs: 10-15% protein
!
Protein Content:
Equids/black rhino/primates: <2% fat
!
Seals: 39-61%
!
Fat Content:
Equids/black rhino/ primates: 6-8% sugar
!
Seals: <1% sugar
!
Sugar Content:
Equids/black rhino/primates: <1kcal/g
!
Seals: 4-6 kcal/g
!
Energy Content:
Dilute (76-83% water) --> Concentrated (65-74% water)
Low fat (2-5%) --> moderate fat (13-16%)
Low protein (3-6%) --> moderate protein (7-15%)
High sugar (6-11%) --> moderate sugar (2-5%)
Low energy (<1kcal/g) --> higher energy content (1.5-2 kcal/g)
Period 1 (young is confined to pouch )--> Period 2 (young can leave
pouch)
!
Marsupial Milk:
Concentrated, high fat, high energy milk
!
May compensate for high heat loss by neonates in cold environment
!
Hooded seal: short lactation (~4 days), grows 22-44 kg/4 days
!
Seals:
Mainly plamitic (16:0), oleic (18:1)
!
Lagomorphs, elephants -mainly capric (10:0)
!
Seals -mainly long chain unsaturated FA (18:3, some 18:1, some palmitic)
!
Fatty Acid Composition:
Usually highest in colostrum
!
Taurine -essential for most mammalian neonates (especially carnivores)
Mule deer -yound nurses 2-10x per day
Single fawn drinks 150-200 g/nursing bout
'hiders' -mother returns to 'hidden' neonate several times a day to nurse
!
Mountain goat -nurses ~40x /day
Single young drinks ~50g/nursing bout
'followers' -neonate follows mother and nurses more frequently than
hiders
!
Intake by Neonates:
Milk:
Mammalian Reproduction:
Testicular growth -0.5% BMR, 3.5% maintenance protein
Sperm production -0.8% BMR
Males:
Ovary and oviduct (produce albumen, shell) -growth is 4% BMR, 28%
maintenance protein
Number varies with age of female (young females may lay
fewer eggs)
!
Number varies with food availability (fewer eggs may be laid
when food is scarce)
!
Egg number:
Size inversely proportional to BW (smaller birds lay larger
eggs relative to BW)
!
Size varies with age of female (young females lay smaller
eggs)
!
Size varies with availability of foods (eggs may be smaller
when food is scarce)
!
Egg Size:
Depends on stage of development of embryo at hatching
!
Young show a marked delay in beocming
independent
!
Young often hatched/born naked, blind and
immbobile
!
Ex. Crows, robins. Starlings, rat, mouse
!
Altricial species:
Young show high degree of independent activity
from hatching/birth
!
Young usually hatched/born with plumage/pelage,
sighted and mobile
!
Ex. Chickens, ducks, white-tailed deer
!
Precocial species:
'nest loving'
!
Young remain in nest being fed for a prolonged
period after hatching/birth
!
Nidicolous species:
'nest fleeing'
!
Young leave the nest almost immediately after
hatching, and start searching for food
!
Nidifugous species:
Altricial -precocial (nidicolous -nidifugous)
!
~40% fresh weight egg -precocial (ducks, geese)
~20% fresh weight egg -altricial (crows, robins)
Yolk size is larger in precocial species than altricial to support
more advanced development before hatching
!
Yolk synthesis (in ovary) takes 4-26 days, albumen synthesis
takes 1-2 days as the ova passes through oviduct
!
Albumin -no lipids, protein (7.1-10.1%)
Yolk contains lipids and protein (13.5-18.5%)
!
Yolk lipid content in higher (34.7-38.3%) in precocial species
than in altricial (23.2-28.4%)
!
1.2:1 -ducks and geese (precocial)
3.6:1 -crows and blackbirds (altricial)
4.9:1 -starlings (altricial)
Albumen/yolk ratio:
!
Egg Composition:
Requirement depends on egg number, egg size, egg composition and
laying interval
!
Egg production
29% BMR, 72% maintenance protein
Hawks, owls (semi-altricial) lay 1 medium sized egg per 3-4 days
!
200+% BMR, 220% maintenance protein
Waterfowl (precocial) lay 1 large, high-energy egg per day
!
Fat deposition prior to egg laying
Mobilizing body fat and protein while laying
Increasing food intake
Changing diet to highly nutritious foods (e.g. Insects)
Meeting requirements for egg laying
!
Egg Laying: daily energy and protein requirements
Heat is needed to start embryonic development in the egg and allow it to
continue
!
Clutch size
Insulation provided by nest
BW of incubating adult bird
Ambient air temperature
Heat required depends on:
!
Normal heat loss through the brood patch is sufficient if ambient
temperature is in the birds thermoneutral zone
!
As incubation progresses, the developing embryo contributes an increasing
heat amount
!
Adult incubating bird has less time to feed
!
Penguins, geese -one parent may do all incubating and rely on fat
deposited before nesting
Canada geese, common eider ducks -loose ~45% BW between
arriving at nesting group and eggs hatching
Some species, both parents share incubation or non-incubating parent may
bring food for the incubator
!
Incubation
Females:
Avian Reproduction:
*Seals are born without lactase
--> lactose-intolerant
*Marsupials can
produce milk with
different content in
each nipple if they
have two young in
different periods
Energy: Reproduction
Friday,*February*10,*2017 12:24*PM
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