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Why is colostrum so important?
synepitheliocorial placentation does not permit any passage of Ig in utero--> calves are born agammaglobulinemic
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What are the benefits of successful passive transfer of IgG? (4)
improved growth rate/ feed efficiency, decreased age at first calving, increased 1st and 2nd lactation milk production, reduced treatment and mortality rates
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How can you quantify successful passive transfer?
- serum IgG >10mg/mL
- serum TP > 5.5g/dL
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When does colostrogenesis occur?
begins 4-6 weeks prior to parturition and stops abruptly after calving
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What is the goal amount of IgG in colostrum?
>50g/L of IgG
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What factors affect the quality of colostrum? (5)
- dry cow vaccination program
- feed balanced dry cow ration
- avoid dry cow stress
- avoid short dry period (<21 days)
- harvest colostrum w/i 1-2hr of parturition
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How do you use a colostrometer to measure the quality of colostrum?
- test milk at room temperature (cold temp overestimates IgG, hot vice versa)
- measures specific gravity
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Why is it important to get calves colostrum quickly?
progressive loss of ability to absorb IgG, completely lost by 24hr
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How long after birth should a calf get colostrum?
goal is to feed 1-2hrs after birth, maximum 6hr
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What quantity of colostrum should we provide at first feeding?
- 150-200g of IgG
- 3-4L within 6 hours (~10% of BW)
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The mass of IgG consumed is determined by... (2)
IgG concentration (colostrum quality), volume of colostrum
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Why is suckling mom for colostrum NOT recommended? (3)
high rate of FPT due to delays in suckling, don't know volume consumed, increased risk of pathogen exposure (JOHNES)
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What are our cleanliness goals for colostrum?
- total plate count <100k cfu/mL
- total coliform count <10k cfu/mL
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The number of bacteria in colostrum doubles every __________ that it sits a room temp and is not used.
20 minutes
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What are critical control points to reduce colostrum contamination? (7)
ID Johne's infected cows, udder prep before harvest colostrum, CLEAN equipment, pasteurize colostrum, use colostrum within 1-2hr or refrig, refrigerate for max 24hr if not going to feed, freeze max 6 months if not going to use
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What is the method of heat treatment for colostrum?
140 degrees F for 30 minutes (as opposed to milk, which is high temp for a short time--> this causes unacceptable thickening of colostrum and decreases IgG)
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What is the difference b/w colotrum supplements and replacers?
supplements do not have enough IgG; replacers have adequate conc of IgG
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What is the goal for serum total protein on farm?
>90% of calves have TP>5.2g/dL or >80% of calves have TP>5.5g/dL
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