Term
| When does development of lactation in mammary gland begin |
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Definition
| 3 weeks prior to calving???? |
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Term
| Why does DMI drop pre-partum? |
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Definition
-burning NEFA in lever
-crowding
-heat stress
-dietary changes
-social changes |
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Term
| When do the majority of metabolic problems occur in dairy cows? |
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Definition
| the first 4 weeks of lactation |
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Term
| What is the economic impact of periparturient disease? |
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Definition
-unrealized milk production
-treatment costs
-discarded milk
-delayed or non-pregnancy
-culling
-death |
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Term
|
Definition
hypocalcemia / parturient paresis
-large, rapid output of calcium into colostrum, reducing blood Ca and inhibiting milk production |
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Term
| What cows are typically affected by milk fever? |
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Definition
| cows in their 3rd lactation, esp. Jerseys |
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Term
| What are the clinical signs of milk dever? |
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Definition
Stage I
-unsteady on feet, cool extremeties
Stage II
-unable to rise, depressed
Stage III
-lying flat out
-bloating, death |
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Term
| How is milk fever treated? |
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Definition
-IV Ca injection (short duration of effect)
-oral calcium gel or drench
-subcutaneous Ca injection |
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Term
| What are the outcomes after treatment for milk fever? |
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Definition
Recovery but with production loss, risk of other diseases
Relapse
Downer cow syndrome
-ischemic necrosis of hind legs, 2/3 will die |
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Term
| How can you prevent milk fever? |
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Definition
Extra dietarycalcium is not absorbed a fast as the loss of Ca to colostrum
Dietary Cation Anion Difference
-balance diet to create a slight negative charge, producing metabolic acidosis to facilitate mobilization of Ca from the bone
-feed low calcium, low potassium, adequate magnesium
-PTH via Vit D3 can also enhance absorption |
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Term
| What are the consequences of subclinical hypocalcemia? |
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Definition
-increased odds of culling
-lower milk yield in early lactation
-reduced immune function |
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Term
| What are the primary metabolic fuel sources for cows? |
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Definition
|
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Term
| How are carbohydrates digested by cows? How is energy mobilized later? |
|
Definition
carbohydrates are converted to fat
-starch & fibers converted to VFA's
Cows must perform gluconeogenesis to create glucose for milk production
-can mobilize fat as a source of energy but this is not enough to substitute for glucose completely |
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Term
| How do cows make up for the difference when they can't physically eat enough to meet energy demands at peak lactation? |
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Definition
| mobilizing fat stores (NEFA) |
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Term
| What is the body's adaptive responses to a negative energy balance? What are the issues? |
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Definition
Spare glucose, shift to using fat as fuel
challenge: fetal & udder demand for glucose
Burn NEFA, increase gng from glycerol & propionate
-some glucose is required in order for FA's to enter the Kreb's cycle, otherwise they will be converted to ketones |
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Term
| What will the results be of an unsuccessful response to a negative energy balance? |
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Definition
| ketosis and fatty liver as the NEFA will be incompletely oxidized |
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Term
| What are some of the health effects associated with pre-partum NEFA? |
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Definition
-increased risk of a displaced abomasum
-increased risk of retained placenta
-increased risk of subclinical ketosis
-decreased neutrophil function |
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|
Term
True or False
All transition dairy cows are in a negative energy balance |
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Definition
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Term
| What are the issues of concern for transition dairy cows in NEB? |
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Definition
-degree of NEB
-success of adaptation |
|
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Term
|
Definition
-excessive rate of breakdown of body fat, leading to incomplete oxidation and increased level of ketones
-low blood glucose |
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Term
| What are some of the ketone bodies that would be found at elevated levels in the blood? |
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Definition
-beta hydroxybutyrate
-acetoacetate
-acetone |
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Term
| What are the signs of clinical ketosis? |
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Definition
-decreased feed intake
-decreased milk production
-firm, dry manure
-loss of body weight
-ketones in milk/urine
-nervous signs |
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Term
| What is sub-clinical ketosis? |
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Definition
-elevated circulating level of ketone bodies, but no clinical signs
-usually a cumulative effect 2 weeks post-partum |
|
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Term
| What are the health effects associated with sub-clinical ketosis in early lactation? |
|
Definition
-increased risk of abomasum displacement
-decreased milk production
-increased severity of mastitis, impaired neutrophil function
-decreased pregnancy rate
-increased risk of anestrus |
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Term
| What is the recommended treatment for ketosis? |
|
Definition
Provide additional energy to decrease ketone production
-propylene glycol
-corticosteroids
-dextrose IV
-correct the basic nutritional/management problem that is limiting the peripartum DMI |
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Term
| What is DA? What are the effects |
|
Definition
displaced abomasum
-shift of the abomasum, typically to the left
-associated with accumulation of gas & lack of abomasal motility
-restricts passage of feed, leads to anorexia, diarrhea, decreased milk production, ketosis |
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Term
| What are some of the risk factors for LDA? |
|
Definition
Fat Cows
Twins
Dystocia
Retained placenta
Milk fever / hypocalcemia
Ketosis
Metritis |
|
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Term
|
Definition
Rolling (will relapse)
Surgery (very successful) |
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Term
| What is sub-acute rumen acidosis? What are the effects? |
|
Definition
-episodes of low rumen pH daily
-impaired rumen functoin
-reduced feed intake
-loose manure, diarrhea
-reduced milk yield & milk fat
-laminitis
-poor non-specific immunity |
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Term
| What is the optimum rumen pH? |
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Definition
|
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Term
| What factors in ration formation & delivery might affect sub-acute rumen acidosis? |
|
Definition
-high grain intake
-errors in formulation e.g. moisture changes
-irregular feeding schedules
-short particle size (lack of effective fiber)
-over mixing of feed |
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Term
| What should the goal be in regards to managing transition cows? |
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Definition
| optimize metabolic health & immune function |
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Term
| What are some of the management considerations on the 'transition checklist'? |
|
Definition
-30" bunk space per cow
-<85% stocking density
-10m2 of bedded pack per cow
-comfortable stalls
-less than 24h in calving pen
-separate heifers
-minimize group changes
-provide heat relief if necessary
-BCS of 3.0-3.5 at calving |
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Term
| What should the BCS be of a cow at calving? |
|
Definition
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