Dairy Nutrition Flashcards
Describe the canadian dairy system and why
- Total milk production responds to Canadian demand
- Each farmer needs a quota/permit to produce a certain volume of milk
o Penalty for over/under production
o Quota based on amount of butterfat per day - To avoid surplus/shortage/price fluctuations + guarantee a consistent price/income for famer
How is milk production in canada regulated/overseen
National Quality Assurance Program: proaction
* Mandatory on all Canadian farms
* Framework for: milk quality/food safety/animal care/traceability/biosecurity/environment…
* Independent validators
How are diary cows in canada housed?
- When lactating: all indoor housed
- Free stall mainly (some tie stall)
What are the goals for feeding young dairy cows
- Keep alive/healthy
- Ensure good growth: should be double birth weight at weaning (>750g/d)
- Speed up rumen development
- Energy and protein are used for maintenance and growth
Compare natural and dairy barn feeding of dairy calves: how often are they fed? What do they eat? When do they wean?
- Natural
o Meals every 6-12h
o First solid food = fresh grass
o Weaning from 6-10mo - Dairy farm feeding
o Milk given BID
o First solid food = grain
o Weaning from 8-10 weeks
What is the primary digestive structure of the pre-ruminant calf? What is the timeline for change?
- Abomasum is the largest
- Rumen is very small
o Develop at 6 months
o Physical development: depend on feed type
o Microbiota develop
What type of digestion does a calf undergo? How is this facilitated
- Reticular groove: bypass rumen (esophagus > omasum)
o Closed by suckling reflex - Monogastric – depend on digestive enzymes in abomasum (hydrolysis)
What important enzymes are involved in digestion in pre-ruminants
- Monogastric – depend on digestive enzymes in abomasum (hydrolysis)
o Chymosin/renin = slow digestion (cheese formation – fat + casein)
o Pancreatic enzymes = digest whey (water/mineral/lactose/proteins)
What occurs if the rumen is not bypassed in pre-ruminants? Why might this occur?
- Reticular groove: bypass rumen (esophagus > omasum)
o Closed by suckling reflex
Head must be elevated
Bucket feeding on the ground = risk
If tube feeding a calf – will do to rumen (cannot reach omasum) - But if giving early its ok (colostrum is more important)
o If not bypassed: acidosis/diarrhea
What are the 3 main phases of rumen development
o Liquid feeding: milk/milk replacer
o Transition: milk/milk replacer + solid feed
o Ruminant: solid feed/microbial fermentation
What is a critical aspect of nutrition for a day 1 calf? Why?
- Immature immune system because the synepitheliochorial placenta does not allow Ig transmission
o Require colostrum (nutrients/lactoferrin/growth factors/prebiotics)
o Failure of passive transfer = higher morbidity/mortality
What are the 5 Q’s of colostrum
- 5 Q’s of colostrum
o Quality: IgG concentration (more dense if good quality – use specific gravity)
High producing dairy cow colostrum = poorer quality
Beef cows usually have better quality
Heifers = lower quality vs cows (because they’ve been exposed to less pathogens)
o Quickness: within 6h (max 24h)
o sQueaky clean: reduce bacterial contamination
o Quantity: 10% BW minimum
quantify:transfer of passive immunity/serum total protein (IgG)
What are 3 options if no maternal colostrum is available for dairy calves? What is one main limitation?
- If no colostrum
o Colostrum bank: freeze up to a year, thaw in 40-60C water bath
o Colostrum replacer: spray dry bovine colostrum, 100-150 IgG/dose
o Colostrum supplements: don’t actually replace colostrum, 40-60 IgG/dose
o But no farm specific antibodies
What is transition milk?
- Transition milk: milk made 2-3d after calving
o Fed 2-7 days post calving (cannot sell)
o Nutrients: milk < transition milk < colostrum
What are the benefits of transition milk
o Bioactive components stimulate intestine villi development
o Increase weight and health score
What lifestage of dairy cows are at most risk for GI dysfunction
calves
What is the typical feed for a calf? What are the characteristics of the components?
- Liquid feed (milk + water) + dry starter feed
- Milk replacer: check protein source (if <3 week = cannot digest plant protein)
o Use whey/milk protein when <3 weeks - Dry starter feed: digestible/palatable (sugar > starch), need water to consume
How does the rumen develop in a dairy calf? How?
- Rumen development: if not ready then the calf will struggle post-weaning
o Development: Increase surface area for absorption via ruminal papillae
o Feeding starter early stimulates papillae development
o Make VFA – butyrate = stimulate papillae growth (to avoid acidosis)
What is the timeline for weaning a dairy calf
Day 2 – Wean
* Week 1: low intake of starter + milk
* 2 – 6 weeks: fixed milk per day (6-8L/d) + increased starter intake (300g/d)
o Gaining weight = higher requirements
* 6-8 weeks: reduce milk provided + increase starter
o Prepare for weaning
How is forage requirements met for dairy calves
- Forage/NDF: have low requirement –via finely chopped hay
Why is water important for dairy calves? How should you administer?
- Water: offered from week 1
o Warm (16-18C) – stimulate water intake
o <1 week = 1.5 L/d
o 1-3 week: 1.5 – 3L/d
o Limited water = limits starter intake
What are the pros and cons of group housed calves
- Concerns with calf health due to ventilation but not a lot of evidence – all in all out = reduce disease
o Cross suckling – can cause mastitis/non-functional teats – avoid if not hungry - Advantages: social interaction/facilitate transition to solid feed
o Reduce labour/management
What are the features of automated feeders
- Automated feeders
o Feed more milk – many meals per day
o Need proper clean/sanitize
o Radio-frequency ID tags = controlled feeding
What is the thermoneutral zones of calves d0, d10, d20
o Thermoneutral
Newborn 15C
10 d = 10C
20 d = 8C
