Peripartum Dairy Flashcards
transition
change from one state to another
How much milk can a dairy cow produce at peak?
150-180 pounds per day
Peak milk production occurs how many days post-calving?
50-60 days in milk
What is the range when a dairy cow may begin producing milk?
21d before to 21d after calving
Energy requirement change in postpartum cattle?
doubles! (basically same story for protein and calcium too)
Do cows who transition well lose weight?
yes - they eat well but the requirements are so big they still lose weight
For how long after calving does highest production occur?
1st 100 days after calving
lipolytic
mobilization of fat
hepatic lipidosis
can occur if too many triglycerides are stored in the liver prior to calving
4 Consequences of a Fatty Liver
- Low dry matter intake
- Low milk production
- Decreased rate of gluconeogenesis
- Impaired immune function
Why do we want dairy cows to mobilize fat prior to calving?
supports milk production
triglyceride
3 fatty acids and a glycerol
What happens when acetyl CoA supply exceeds TCA cycle capacity?
they turn into ketones! –> ketosis
TCA (Krebs) Cycle
essentially peeling off 2 carbon units at a time, run the cycle, prooduce acetyl CoA (listen to lecture to clarify this card)
ketosis
peripheral tissues do not have the capacity to use all of the ketones that are produced so they accumulate in the blood
beta-hydroxybutyrate
can measure this to detect clinical or subclinical levels of ketosis
Ways for the body to get rid of ketones?
breath (smells “sweet” from acetate?), urine
Symptoms of ketosis?
decreased dry matter intake, decreased milk production
LDA and metritis
metritis
inflammmation of the uterus
Ways to prevent ketosis or fatty liver?
don’t overfeed dry cows and only feed energy to MAINTENANCE needs and no more, use low quality forage like straw
choline
improves export of liver triglycerides
niacin
decreases lipolysis
chromium
reduces insulin resistance
Non-Dietary Issues that affect the Dairy Cow
stress due to overcrowding in poorly designed stalls or too many cows, heifers and older cows mixed, heat
Catecholamine
increases in times of stress and increases lipolysis and the movement of fat
3 Reasons Cows ave Increased Calciium Needs
- Growth
- Fetal growth (during late gestation)
- Lactation!
3 Locations in the Body for Regulation of Calcium
- Kidney
- Bone
- GI
Kidney and Calcium Regulation
fast, limited capacity
Bone and Calcium Regulation
slow, moderate capacity
GI and Calcium Regulation
slow, large capacity - time is needed to upregulate the number of calcium in the tract
Risks of Subclinical Hypocalcemia
retained placenta, LDA, dystocia, uterine pprolpse, immunosuppression, ketosis
Signs of Clinical Hypocalcemia
less than 5mg/mL of calcium in serum
generally will find these cows ataxic, if not entirely recummbent, can’‘t get up, cold extremities
DCAD
dietary cation-anion difference
3 Ways to Control Ca2+ at calving
- manipulate DCAD
- Limit calcium in diet (don’t want too much, but this is tricky to do!)
- Extra Vitamin D
What is DCAD?
feed an excess of anions during last weeks of dry period (typically Cl- in the form of soybean meal and HCl or bichlor) in order in induce a mild metabolic acidosis to increase urinary excretion of calcium and increase PTH receptor binding
Low Calcium Diet?
hard to achieve, can also use calcium binnding agents like Zeolite and phytic acid
Extra Vitamin D diet?
can be toxic at too high doses, typically done in combination with a negative DCAD diet for calcium homeostasis
Transition Cow Diseases (5) secondary to energy and calcium homeostasis imbalance
- retained placenta
- metritis
- milk fever
- ketosis/fattty liver
- LDA
Clinical hypocalcemia is also known as?
milk fever
