Exam 2 Flashcards
quarters or glands
The four parts of the udder
Udder
the mammary gland
mammary fat pad
essential for development of the mammary epithelium, providing signals that mediate ductal morphogenesis and, probably, alveolar differentiation
udder cleft
the anterior junction between the udder and the abdominal wall or between the front quarters
lateral suspensory ligaments
provide substantial support for the udder
teat
the projection from the mammary glands of mammals from which milk flows or is ejected for the purpose of feeding young
streak canal
The only orifice of the gland between internal milk secretory system and the external environment
sphincter muscle
The circular smooth muscles in their contracted state function to maintain tight closure of the teat canal between milkings to prevent leakage, and to keep keratin occluding the canal lumen compressed as an aid in preventing bacteria from progressing upward into the teat cistern
Mammary alveolus/alveoli
hollow cavities, a few millimeters large
Alveolar epithelial cell is
the secretory cell lining the alveoli
Ductal epithelial cells
the epithelial cell lining of the pancreatic duct that deliver enzymes from the acinar cells to the duodenum
myoepithelial cells
modified epithelial cells found in sweat, mammary, salivary, lacrimal, and tracheobronchial glands
endothelial cells
lining the blood vessel
leukocytes
white blood cells
Blood supply flow
artery
arteriole
capillaries
venules
veins
Diffusion of nutrients
uptake by cells
removal of waste
Lumen
Direction of milk flow
Alveoli
ducts
gland cistern
teat cistern
How do nutrients get from feed to the mammary gland
digestion
absorption
metabolism
circulatory and blood flow
what do ruminants do best
forage
Glucose-sparing
try to not use glucose if we can help it
2 organs that need glucose
brain
mammary gland
Rate-limiting
1st limiting
Dilution of maintenance
efficiency
Homeorhesis
setting metabolism and physiology to support a specific function
Homeostasis
maintenance
Metabolic disorders
what we get when the shift from dry cow to lactating doesn’t work
Near the end of gestation, the growing fetus demand how much of the cows energy
around 10%
At peak lactation, the lactating mammary gland demands how much of the cows energy
about 80%
Pre-absorptive organs
Mouth and esophagus
Reticulo-Rumen
Omasum
Abomasum
small intestine
large intestine
Function of mouth
wetting and mastication (chewing)
Rumination
Grazing
Rumination
cud-chewing
regurgitate bolus or cud
Function of esophagus
swallowing food
getting it to the rumen
Function of the Reticulo-Rumen
Cellulose degradation via fermentative digestion. Rumen bacteria produce cellulose.
VFA production
Less complex CHO fermented
Protein digestion begins
non-protein nitrogen used to produce bacterial protein
water soluble vitamins produced by rumen microorganisms
increase in gut fill with lactation
VFA’s
volatile fatty acids
volatile- means they can evaporate and be absorbed through the rumen wall into the blood stream
Rumen is not entirely ___ because it can absorb VFA’s through the wall
pre-absorptive
the three VFA’s
acetate
propionate
butyrate
There is how many lipids in the diet
limited, most likely saturated in low pH rumen
come from seed oils, oils in plants
Protein consumed ____ Protein digested
does not equal
digesta entering the omasum is
high in protein and lipid
low in carbs- converted into VFAs in reticulo-rumen
Omasum function
unsure
say absorbing water
concentrates digesta
Abomasum function
chemical digestion of proteins by HCl and pepsin in the abomasum
Small intestine function
extensive enzymatic digestion of peptides, amino acids then absorbed and enter hepatic portal circulation
Gluconeogenesis
making glucose
happens in the liver
critical to metabolism
Duodenum function (part of small intestine)
bile salts secreted to emulsify triglycerides
Lipase
act to produce free fatty acids, mono- and di- glycerides which are absorbed into epithelial cells of the small intestine
With lactation what changes happen to the omasum, abomasum, and SI
increase in size
Cycle of bile
made in liver
stored in gallbladder
released when lipid is in the tract
emulsify lipids so the lipase can access the smaller parts (more surface area)
Function of the large intestine
absorption of water and minerals
fermentation occurs, provides some energy via VFA’s absorbed across intestinal wall
Water absorption increases with
lactation
Homeorhetic shift in dairy cows
in partitioning of nutrients toward mammary gland at onset of lactation
Preabsorption is all about
ingestion and digestion
Liver is
central!
Postabsorptive metabolism
nutrients absorbed from gut
carried by portal vein to liver
then other organs
How much blood does it take to support 1 volume of milk production
500 volumes
Mammary gland metabolism does what during lactation
pulls perfusion
Plasma volume does what to accommodate demand for mammary perfusion
increases
mammary gland pulls
nutrients
Preabsorption is about
ingestion and digestion
Postabsorptive Metabolism
nutrients absorbed from the gut
carried by portal vein to liver
Liver is central!
Then to other organs
Storage depot for fatty acids
fat
storage depot for amino acids
muscle protein
storage depot for glucose
glycogen and in fat
storage depot for calcium and phosphate
bone
Job of the Kidney
Filters the blood
produces urine
reabsorption of water
Water intake does what with onset of lactation
increases
milk is 88% water, so water intake is crucial
How does the kidney change during lactation
adjust to reduce water excretion
Job of the liver
gluconeogenesis
nutrient partitioning of carbs, protein, and fat
Hepatic portal circulation
drains GIT and delivers absorbed nutrients
precursor for hepatic gluconeogenesis
propionate
Glycogenolysis
making a string of glucose- glycogen for storage
Fatty liver is caused by
liver picking up fatty acids to package it but there is a lack of glucose so it stores the fat instead
What provides energy source and substrate for fatty acid synthesis
acetate and butyrate
propionate is used for gluconeogenesis
What is synthesized in the liver
triglycerides
Ionophores do what
increase propionate and decrease acetate-leads to increased milk
Leptin does what
regulates appetite
Adipose tissues major function
store fat/energy
mobilize fat/energy
Job of bones
structural framework
mineral reserve
What hormone stimulates calcium uptake at the gut and mobilization from the bone
parathyroid hormone
Calcitonin does what
prevents elevated calcium in blood
Milk fever happens when
mammary gland hog the blood calcium
muscles need calcium to contract
heart is a muscle
How do we prevent milk fever for dry cows
dry cow diet that puts the cow in mobilization mode not by feeding calcium
The mammary gland needs what to make lactose
glucose
Glucose sparing mechanisms include
acetate utilization for energy
no pathway for glucose use for lipogenesis
glucose used for lactose synthesis in mammary epithelial cells
Mammary glands uptake of amino acids does what during lactation
increases
First limiting in milk production
methionine and lysine
UIP
undegradable intake protein
may improve available amino acid supply
Composition of milk
Total solids-12%
-Lactose 5%
-Fat 4%
-Protein 3%
milk fat is how much triglycerides
98%
milk protein is how much casein
80%
Fatty acids we need to make triglycerides come from
circulation (blood from the adipose tissue)
mammary glands (make their own)
In early lactation cows are in
a negative energy balance because the DMI cannot match output
Cow comfort is good for
farm reports
-good example of how investment/management
-how much money does a management problem cost
We design stalls so that
cows lay naturally and comfortably but poop in the alleyway
Diagonal lying check list
is the stall too short
is there a front lunge or bob zone space obstruction
does the loop design promote side lunge
is the brisket locator higher than 4 inches
is the brisket locator too close to the rear curb
is the neck rail too close to the rear curb
is there a social obstruction
goal of cow comfort
create an environment that allows the cow to carry out natural behaviors with consideration of management constraints
improve productivity and efficiency
Social hierarchy
pecking order
primiparious
1st calving
multiparious
more than one calvings
stocking/density rate
how many cows per pen
pen moves
stressful
change which cow is with which cow
turnover rate
how quickly you make pen moves
what type of barn does Foremost have in terms of stall rows
4 rows, head to head
CCI
cow comfort index
cows lying properly/cows in a stall X 100
Goal 80%, top herds can achieve 90%
RI
rumination index
cows chewing cuds/cows in stalls X 100
Goal 50% of cows lying down should be chewing cud, top herds can achieve 65%
SSI
stall standing index
SUI
stall use index
Knee-drop test
a way to test the comfort of the bedding in the stalls by dropping to your knees
Behaviors associated with Cow comfort
eating
resting
rumination
drinking
social
grooming
Factors that affect behavior and time budgets
facility design
stocking density
time spent away from the pen
length of time spent confined
grouping strategies/competition
ventilation, temp, humididty
human interaction
Daily time spent eating
5-5.5 hours
Daily time spent Resting/rumination
12-14 hours
Daily time spent standing, walking, idling, grooming, social, estrus
2-3 hours
daily time spent drinking
0.5 hours
hours needed per day for natural behviors
20.5-21.5 hours
Cows will sacrifice what if their resting time is not adequate
feeding
Cows will spend more time waiting for a place to lie down than eating when they are
overstocked
Resting and rumination is associated with
greater DMI and milk yields
increased rumination is associated with
rumen health and milk fat yield
maximize DMI by
encouraging more meals and avoiding fewer, larger meals
Factors affecting number and size of meals
competition
inconsistent feeding schedule
infrequent pushups
heat stress
inadequate lying time
Fewer and larger meals result in
reduced rumen health and feed efficiency
SARA
sub-acute ruminal acidosis
Rumen pH drops because
Microbes start making lactic acid instead of VFAs
Sand is used in beddings because it is
inorganic
can not host microorganisms
Natural resting postures
long
short
wide
narrow
Rising motion of a cow
lunge-bob
Mature Holstein needs ___ of lunge space for normal rising
30 inches
Attention needs of the cow has a
low cost compared to the return on investment
Perching
a cow with her front legs in the stall but back legs in the alley
Defensible resource
resources such as water, feed bunk, or stalls that the cows will fight over
Bedded Pack Barns
has no stalls just a bedding area
ventilation is important
should not overstock for it to work
Benefits of bedded pack barns
improved cow comfort and cleanliness
low maintenance
improved feet and legs
decreased SCC
increased heat detection
increased production
less odor and fewer flies
increased longevity
low investment costs
less concern with cow size
improved manure value for crops
Overstocking advantages and disadvantages
beneficial to return on facility investment
reduces the ability to express natural behavior
Transition Cow metabolic disorders
milk fever
ketosis
fatty liver
displaced abomasum (LDA or RDA)
-related- Mastitis, retained placenta, metritis
What is a transition cow
periparturient cow
Dry-calving-lactating
Goldilocks diet
feeding straw as a filler
dry cows should eat how much
2% of their body weight
