Term
At what life stage does a dairy cow have the highest mortality risk? Morbidity? |
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Definition
Pre-weaning calves are at the greatest risk of morbidity and mortality |
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Term
What are the major causes of calf morbidity pre-weaning? |
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Definition
Diarrhea / Digestive (~60%) Respiratory (~32%) Navel (4%) Other (2%) |
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Term
What are the major causes of calf mortality pre-weaning? |
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Definition
Diarrhea / Digestive (56%) Respiratory (22%) Unknown (8%) Calving (5%) Miscellaneous (5%) Joint / Navel (2%) Injury (2%) |
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Term
What is the average rate of pre-weaning mortality? |
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Definition
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Term
What are the 5 C's of successful calf rearing? |
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Definition
Colostrum Cleanliness Consistency Calories Comfort |
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Term
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Definition
bacteria in the bloodstream |
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Term
What are some of the important diseases of dairy calves? |
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Definition
neonatal calf diarrhea pneumonia septicemia navel omphalophlebitis (umbilical inflammation) umbilical hernia |
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Term
What is passive transfer of immunity? Why is it important? |
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Definition
post-natal transfer of antibodies from cow to calf via colostrum
important because antibodies are too large to cross the placenta in ruminants, and they are essential as they bind to & help remove pathogens |
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Term
What are the important qualities/considerations regarding colostrum? (4) |
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Definition
Quantity Quality Quickness Cleanliness |
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Term
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Definition
the first milk produced by the cow, rich in nutrients and immunoglobulins |
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Term
What factors affect the quality of colostrum? |
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Definition
Vaccination Nutrition of dam Heat stress Leaking Cleanliness of harvest Volume (roughly inversely proportional) |
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Term
Rank the following in order of the quality of colostrum they produce:
Mature dairy Dairy heifers Beef cattle |
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Definition
Beef Cattle > Mature Dairy > Dairy Heifers |
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Term
How can you test quality of colostrum? |
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Definition
Specific gravity (colostrometer)
Ig / total protein in calf serum (1-7 days old) |
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Term
What is the minimum amount of IgG you should aim to have delivered to a calf via colostrum? |
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Definition
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Term
What minimum volume of colostrum should a calf ingest in their first 24h of life in order to absorb enough IgG? |
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Definition
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Term
What are the requirements for successful transfer of passive immunity from cow to calve? |
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Definition
The calf consumes a sufficient amount of antibodies -depends on the [IgG] of the colostrum and the volume of colostrum
Calf absorbs the colostral antibodies -depends on how long after birth the colostrum is consumed -cleanliness of colostrum also a factor |
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Term
What effect does colostrum deprivation have on calf mortality? |
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Definition
74X greater risk of death in the first 21 days of life! |
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Term
What are some strategies for feeding colostrum? |
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Definition
4L in first feeding <6 hrs after birth
4L at first feeding, 2L at 2nd feeding
2 feedings of 2L in 4-8hr intervals |
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Term
Why is relying on suckling not an effective means of passive transfer of antibodies? |
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Definition
-many calves do not manage to suckle within 6hrs -no way to know the volume of colostrum consumed -increased risk of ingestion of manure, hair etc. |
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Term
How does an esophageal feeder work? What are the pros/cons? |
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Definition
Tube down esophagus directing colostrum to rumen -milk will move to abomasum within 2-4 hours
Pros: very safe, easy to manage volume Cons: equipment must be cleaned well, possible reduction of absorption efficiency
(absorption issues overcome by the volume fed & proper timing of feeding) |
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Term
True or False
Colostrum replacers an supplements are equally as effective as colostrum produced by a cow |
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Definition
False
They have reduced absorption efficiency (35-40%)
-must be fed correctly and promptly for these to work |
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Term
What are some potential sources of contamination of colostrum? Which is the most common? |
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Definition
-from teat -in bucket (most common cause of contamination) -coming out of tube feeder |
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Term
True or false
With strict udder preparation, 100% of milk samples coming out of a cow are safe |
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Definition
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Term
How long can colostrum be safely refrigerated? |
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Definition
1 day
or up to 2 days if potassium sorbate is added |
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Term
Describe the proper cleaning procedure for milking equipment? |
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Definition
1. Take apart all hoses, lids etc 2. Rinse with warm water (105F) 3. Soak in hot water (>120F) 4. Scrub all surfaces with >140F water & soap/chlorine detergent, use gloves! 5. Rinse with hot water & acid 6. Drain & air dry |
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Term
What is ETEC? What does it do? |
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Definition
enteropathogenic E. coli
-attach to pili of intestinal epithelial cells -gut absorbs the endotoxin, which causes excessive secretion of water & salts -results in diarrhea |
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Term
When is ETEC most likely to affect a calf? What are the typical symptoms? |
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Definition
Less than 7 days old
-profuse, watery, yellow diarrhea -severe depression -dehydration |
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Term
At what age do rotavirus & coronavirus affect a calf? Which is more severe? |
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Definition
Rotavirus: 5-15 days Coronavirus: 5-21 days more severe |
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Term
What effect to rotavirus & coronavirus have on a calf? |
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Definition
-tips of villi are destroyed -prevents digestion & absorption of milk -osmotic pressure causes increased water secretion into intestines, sometimes blood -diarrhea results |
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Term
What is cryptosporidia? At what age is a calf most susceptible? |
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Definition
parasite which causes atrophy of villi, preventing digestion -not treatable -zoonotic
affects most at 5-35 days of age |
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Term
True or False Salmonellosis can affect mature cows as well as calves |
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Definition
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Term
What is salmonellosis? What are the symptoms? |
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Definition
bacterial intestinal disease, causes wrinkled, rough intestinal epithelium
-high fever, depression, blood & fibrin in stool |
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Term
What are the 2 branches of treatment for diarrhea |
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Definition
Correct the fluid loss
Antimicrobial treatment |
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Term
What level of dehydration would result in mortality? |
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Definition
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Term
What is the goal of treating dehydration? What are some appropriate methods? |
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Definition
-replace fluid deficit -replace electrolytes (Na, K, Cl, HCO3) -correct metabolic acidosis
Mild/moderate dehydration: oral fluid therapy w/ esophageal tube & electrolyte solution
Severe: IV fluid therapy |
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Term
What are some of the drawbacks of antimicrobial treatment of diarrhea? |
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Definition
-difficult to clinically ascertain there is a microbial infection -bacteria can be resistant -not effective if the issue is viral / cryptosporidia -may inhibit 'good' bacteria |
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Term
What methods of handling colostrum should be considered to improve prevention of diarrhea? |
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Definition
-4L fed in first 6-12H -goal of 6L total within 24H -cleanliness in harvest & feeding -colostrum from one dam to one calf -hand feed by bottle or esophageal feeder -freeze extra 1st milk colostrum |
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Term
How can you improve the host specific immunity of colostrum? Why does this work? |
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Definition
-vaccinate pregnant cows with E.coli vaccine
-improves the level of specific IgG in colostrum |
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Term
What are the 3 means of preventing calf diarrea? |
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Definition
Improve immunity of calf via quantity & quality of colostrum Improve specific immunity of colostrum Improve nutrition (no soy protein source) |
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Term
What is the thermoneutral zone for calves <21 days of age? >21 days? |
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Definition
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Term
What is the traditional approach of feeding dairy calves? What is the issue? |
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Definition
10% of birth weight (2L) 2X a day, goal is to get calf on solid food by 4-5 weeks
-this volume is below maintenance level for a 50kg calf at 0C , need at least 5L |
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Term
How much milk with a calf drink if given free choice? What are the benefits of this? Cons? |
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Definition
8-12 L per day
Pros: -accelerated growth rate -produce up to 500kg more milk in first lactation
Cons: -more expensive -milk may spoil (can prevent this with acidification!) |
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Term
Describe an example of a milk feeding program for holstein calves |
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Definition
-6L colostrum in first 24h
-milk/replacer 2+ feedings per day or ad libidum
6L/day in week 1 8-10L/day in week 2-7 4L/day in week 8
Wean at week 8
*offer water & starter grain free-choice throughout this process |
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Term
True or False
Pasteurization and sterilization are the same thing |
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Definition
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Term
Why would you pasteurize milk? |
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Definition
To treat waste milk to it can be fed at a different time |
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Term
What management practices can reduce the risk of exposing a calf to pathogens? |
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Definition
-calve in a clean environment -use clean equipment -remove calf from cow immediately after birth -keep calf in a hutch or individual pen until weaning -use isolation facilities for sick calves -use group pens after weaning? |
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Term
True or False
Enzootic pneumonia can be caused by both bacteria and viruses |
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Definition
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Term
What are some symptoms of enzootic pneumonia? |
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Definition
-upper respiratory bronchopneumonia -mild to high fever -coughing & nasal discharge -sometimes reduced growth rate |
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Term
What might cause enzootic pneumonia? |
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Definition
poorly ventilated enclosure -high humidity, ammonia, exposure to other cattle
inadequate IgG levels overcrowding temperature fluctuations poor nutrition drafts |
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Term
What vessels are found within the umbilicus>? |
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Definition
2 hepatic arteries & 1 hepatic vein
urachus to bladder |
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Term
What is omphalophlebitis> |
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Definition
infection due to poor passive transfer & poor calving hygiene
-local infection in cord, forming abscesses eventually in abdomen up to the liver
-infection can spread to other areas such as joints |
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Term
If a young calf has a joint infection, what is the most likely cause? |
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Definition
spreading of bacteria from the umbilicus (omphalophlebitis) |
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Term
How can you prevent omphalophlebitis? |
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Definition
-clean & dry calving area -disinfect navel with 7% iodine |
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Term
What is an umbilical hernia? What is the typical treatment? |
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Definition
-defect in ventral abdominal wall around the umbilicus
-tape it if small, surgery if large or not treated early enough |
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Term
What is the purpose of ear tagging? |
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Definition
-herd management -ownership -traceability -national disease surveillance & outbreak investigation |
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Term
What are some recommendations for proper dehorning practices? |
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Definition
-dehorn as young as possible -use local anesthetic -use anti-inflam drugs if dehorning >4wks of age |
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