Term
What is Phase I of lactation cycle in a dairy cow? |
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Definition
-day 0-70 -peak lactation occurs at 4-6 weeks |
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Term
What problems occur during Phase I of lactation cycle in a diary cow? |
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Definition
-clinical and subclinical hypocalcemia -ketosis, hepatic lipidosis, LDA, RFM |
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Term
What is PHase II of lactation cycle in a dairy cow? |
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Definition
-day 70-140 -max feed intake at 8-10 weeks: begin gaining weight |
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Term
What problems exist during Phase II of lactation cycle in a dairy cow? |
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Definition
-silent heats, cystic ovaries -low milk fat test, early drop in milk production |
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Term
What is PHase III of lactation cycle in a dairy cow? |
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Definition
-day 140-305 days -mid to late lactation: replace body weight -INSTITUTE PREVENTIVE MEASURES FOR KETOSIS AND HEPATIC LIPIDOSIS |
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Term
What is Phase IV of lactation cycle in a dairy cow? |
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Definition
-day 60 to 21-14 days prepartum -dry period -maitain body condition score for fetal development and colostrum production |
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Term
What is Phase V of lactation cycle in a dairy cow? |
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Definition
=transition phase of dry period: 14-21 days prepartum to parturition -INSTITUE HYPOCALCEMIA PREVENTIVE MEASURES -rumen adaptation to concentrate diet |
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Term
What are the other names for hypocalcemia in a pregnant dairy cow? |
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Definition
-aka parturient paresis and milk fever |
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Term
How common in milk fever in the US? Who is affected? |
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Definition
-5% in the US -metabolic disease of adult dairy cows |
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Term
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Definition
-acute Ca deficiency that occurs during the periparturient period -75% within 24h of calving |
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Term
How does age and production levels affect incidence of milk fever? |
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Definition
-inc age & inc pdn = inc incidence of milk fever |
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Term
What is the physiology behind milk fever? |
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Definition
-demand for Ca > resourced and availability |
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Term
What is the physiology behind dec [Ca] wiht milk fever? |
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Definition
-dec feed intake at calving = dec Ca absorption from GI tract -dec Ca mobilization = tissues refractory to PT => delayed Vit D pdn => dec # Vit D Rc |
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Term
What is the common predisposing factor in the diet that leads to milk fever? |
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Definition
-diet for dry cow: inc K, inc P, dec Mg |
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Term
How does a diet high in K lead to milk fever in a dairy cow? |
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Definition
-causes metabolic alkalosis which dec tissue response to PTH by changing Rc confirmaiton |
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Term
What are the clinical signs of Stage I milk fever in a dairy cow? |
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Definition
-less than 1 hr -ataxic -seak: shifting weight -muscle tremors -hypersensitivity/hyperesthesia -anorexia -mild tachycardia and hyperthermia -tongue extension |
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Term
What are the clinical signs of Stage II milk fever in a diary cow? |
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Definition
-1-12h -sternal recumbency -S-shaped curvature of neck -muscle fasciculation -mild bloat, constipation, full urinary bladder -dilated pupils-tachycardia w/ dec heart sounds -poor perfusion |
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Term
What are the clinical signs of Stage III milk fever in a dairy cow? |
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Definition
-short time period -lateral recumbency -loss of consciousness -severe bloat -muscle faccidity -tachycardia w/ inaudible heart sounds -coma to death |
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Term
What do we see on clin path with milk fever? |
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Definition
-hypocalcemia -hypophosphatemia -hypermagnesemia (due to dec P) -hyperglycemia (Stress) 0inc CPK and AST -stress lekogram |
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Term
How does parturition change calcium homeostasis? |
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Definition
-stim PTH = activate vitamin D = inc Ca and PO4 resorption from bone |
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Term
What problems do we see with altered calcium metabolism due ot parturition? |
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Definition
-dec Vit D -alkalosis due to high K in diet = dec Ca absorption |
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Term
Why does hypocalcemia due to milk fever cuase flaccid paralysis? |
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Definition
-loss of membrane stabilization -inability to release ACh and NMJ -thus dec muscle excitaiton-contraction coupling -enhaced by hypophosphatemia & hypermagnesemia |
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Term
What treatment do we use to prevent Stage I milk fever? |
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Definition
-Ca gels or pastes PO -Ca salts SC |
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Term
How do we treat Stage II and III of milk fever? |
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Definition
-Ca salts IV SLOWLY over 15min -OR Ca soln with P, Mg, K, dextrose |
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Term
Which vessel is best for administration of Ca salts IV for treating stage II or III milk fever? |
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Definition
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Term
What are the signs of successful treatment of stage II or III milk fever? |
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Definition
-inc mental awareness -improve CO: dec HR, inc amplitude and heart sounds -return of smooth and skeletal msucle funciton |
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Term
How frequently do milk fever relapses occur after successful treatment? IN which animals? Clinical signs? |
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Definition
-25-30% w/in 24-48h -in older cows deficient in P, Mg, and/or K -anorexia, alkalosis, anitial PE missed a problem, new complication |
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Term
What are possible complications of milk fever? |
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Definition
-bloat -dystocia or uterine prolapse -aspiration pneumonia -musculoskeletal injury: crush, gastroc rupture, coxofemoral luxation -peripheral nerve injuries -coliform mastitis -LDA |
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Term
How do we prevent relapses and complications of milk fever? |
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Definition
-incomplete milking -SC or oral admin of Ca -good footing -keep cow sternal -provide fresh food, water, and shade |
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Term
How do we prevent milk fever on a herd level? |
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Definition
-DCAD: dietary cation anion difference -use acidogenid diet )inc Cl-/S- anions) to prevent milk fever |
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Term
How do acidogenic diets prevent milk fever? |
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Definition
-dec blood pH: metabolic acidosis = inc bone resorption of Ca -inc Vit D: inc Ca absorption in intestine =defferential absorption of cations and anions in gut = inc Ca absorption |
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Term
In addition to diet, how else do we avoid milk fever at a herd level? |
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Definition
-avoid alfalfa hay -withold K fertilizaiton from field -best - corn silage |
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Term
What is the best anion to add to diet to prevent milk fever? |
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Definition
-ammonium chloride -feed at least 2-3 weeks before parturition during transition phase of dry period |
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Term
What is the major downside to ammonium chloride in the diet? |
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Definition
-unpalatable -sulfate salts taste better |
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Term
Which breeds of dairy cattle are predisposed to milk fever? |
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Definition
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Term
How do we monitor pregnant cows for milk fever? |
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Definition
-urine pH -Holsteins: 6-6.5 -Jerseys: 5.5-6 |
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Term
What is the best prevention method for milk fever? |
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Definition
-oral calcium supplementation around calving: 12h pre to 12-24h post-calving |
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Term
What is the second best prevention method for milk fever? |
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Definition
-parenteral Ca admin around calving SC |
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Term
What is the pathophysiology behind hypocalcemia in beef cattle? |
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Definition
-inc Estrogen in late gestation = dec osteoclast activity |
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Term
What is the epidemiology of hypocalcemia in beef cattle? |
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Definition
-late gestation >>> periparturient |
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Term
What is the etiology of hypocalcemia in pregnant beef cattle? |
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Definition
-inc getal skeeltal demands for Ca -feed deprivation or inadequate nutrition |
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Term
What is the epidemiology of hypocalcemia in pregnatn sheep? |
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Definition
-late estation >> first 6w of lactation |
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Term
What is the etiology behind hypocalcemia in pregnant sheep? |
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Definition
-large fetoplacental units |
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Term
What is the major differential for hypocalcemia in pregnant sheep? |
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Definition
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Term
How do we treat sheep with pregnancy hypocalcemia? How do we prevent it? |
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Definition
-Ca gluconate IV or SC -Prevent: avoid stress 4-6w prior to lambing and maintain a balanced ration |
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Term
What is the epidemiology oc hypocalcemia in a pregnant dairy goat? |
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Definition
-during lacation -at parturition -late estation with multiple kids |
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Term
What are the clinical signs of preganncy hypocalcemia in goats? |
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Definition
-hyperexcitability or mild depression -ataxia |
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Term
If the pH is still too high in a diary cow that is on a DCAD diet, what is wrong? |
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Definition
-mixing error or she is not eating |
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