3 – Feeding Dairy Cattle Flashcards
1
Q
Feeding costs
A
- Single HIGHEST production cost
o AB study: 30-35% total production costs
2
Q
What are the components of a dairy cow diet?
A
- Fiber sources: milk fat production (acetate)
o Ex. alfalfa silage, pea silage, grass silage - Grains: gluconeogenesis (propionate)
o Ex. barley, corn - *some feed provide both grain and fiber
o Ex. corn silage, barley silage
3
Q
Alfalfa
A
- *leaves
o Margin less than ½ serrate
4
Q
Pea silage
A
- Can be difficult to grow alfalfa in some areas
- *tend to see higher milk fat, but lower milk protein (balance each other out in the end)
5
Q
Barley
A
- Feed more in Canada compared to the states
o Grown better here due to temperature
o requires less heat and water compared to corn
6
Q
Making a balanced ration
A
- determine content of available feedstuffs
o near infrared (NIR) + wet chemistry - determine animal requirements
7
Q
DMI vs. milk production rules of thumb
A
- *DMI=critical for milk production
o Diet is usually 50% DM - 6kg ‘tax’ (4.5kg for jerseys)
- Multiple the remaining intake by 2=milk yield
8
Q
If Holstein eating 25kg/day what would the milk yield be?
A
- Take away 6kg ‘tax’=19kg for milk production
- *38kg/day
9
Q
What ‘drives’ DMI?
A
- Bodyweight
- Milk production (producing more=need more DMI)
- Body condition
- Implants
10
Q
What limits DMI?
A
- Ration NDF: fiber
o Too much fiber=sits longer - Ration net energy
o Will get full before having enough to produce milk - Forage mass/allowance
- Ration protein (CP/TDN)
11
Q
What are the environmental factors that change DMI?
A
- Air temperature
- Plant toxins
- Water requirement and intake
12
Q
What is the 3 diets concept?
A
- Formulated
- Delivered
o Loading the mixer: first input of error - Consumed
o Can’t control as well
13
Q
Spanish herds all on same ration
A
- All herds feed the same thing
- *if ration alone was what determined milk production=would assume all the yields would be the same
14
Q
What does increasing age at 1st calving do to production?
A
- Decreases production
o Get more adipose tissue laid in the udder=reduced ability to produce milk
15
Q
What does increasing stalls/cow do to production?
A
- Increases production
16
Q
What does pushing up feed do to milk yield?
A
- 3.8kg more milk
17
Q
What is feed refusals?
A
- when you feed the next time, there is still feed in the feed bunks
- *continually having food in front of them
18
Q
What does feed refusals to milk yield?
A
- 1.6 kg more milk
19
Q
What are the 2 different feeding systems?
A
- Component feeding
- Total mixed ration
20
Q
Component feeding
A
- Ad-lib feeding of forage
- Concentrates fed separately
o Milking parlour
o Computer feeders
o Individual feeding ‘station’
21
Q
What are the disadvantages with component feeding system?
A
- Concentrates may be taken in during short timeframe
- Rumen pH fluctuations
- Competition leading to grain overload
22
Q
What is partial mixed ration?
A
- Some grain is fed in parlor
- *most of grain is mixed with forage
23
Q
Total mixed ration systems
A
- All feed components mixed to form TMR
- Composition of diet tightly regulated
- *appropriate mixing is critical
24
Q
What happens with inadequate mixing in TMR?
A
- Sorting and rumen pH fluctuations
25
What happens with overmixing in TMR?
- Put it into a powder
- Small particles leading to grain overload and/or frothy bloat
26
What are the 7 steps for problem solving a dairy ration?
1. Characterize low production
2. Evaluate Average days in milk
3. Evaluate trends in herd size
4. Evaluate herd nutritional management
5. Evaluate the cows
6. Evaluate cow environment
7. Additional testing
- *rarely do them all at once
27
Characterize low production (1)
- Evaluate milk by time and parity
- If low production in heifers:
o Overcrowding, pen moves?
o Small size at calving?
o Over conditioned at calving?
- If low production in cows:
o Underfeeding?
o Ketosis, lameness?
28
Evaluate average days in milk (2)
- Where in lactation is the ‘average’ cow
- Indicator of reproductive efficiency
o If conceives later=longer lactation
o Longer lactations=average cow further in lactation (ex. 200DIM vs. 155DIM)
- Increased DIM=decreased milk
29
Herd investigation example
- Average DIM=240 with 29kg/cow/day
- *addressed reproductive efficiency issue (ex. one bull had a hurt leg)
o New average DIM=180 with 33kg/cow/day
- NO ration changes
30
Evaluate trends in herd size (3)
- Herd expansions decrease milk yield for up to one year
o Hierarchy is diminished at 150-200 cows (before that would have 2 hierarchy groups)
- Long vs. short term LOW production
31
How do health problems effect herd size?
- Death loss
- Reduced herd size
- Reduced milk yield
32
What is happening with long term LOW production?
- Nutrition problems
- Health problems
- Increased DIM
33
What is happening with short term LOW production?
- Expansions
- Health problems
- Nutrition problems
34
Evaluate herd nutritional management (4)
- Determine which cows are eating
- This takes time
- NEVER assume
- Evaluate feed ingredients
- Determine amount fed
- Check mixer scales
- Reconstruct diet
- Evaluate TMR: CAREFUL SAMPLING
35
Evaluate feed ingredients
- See all feeds
- Understand system
- Analyse dry matter, forage, and grain particles, ensiled feed pH
36
Determine amount fed
- Interview feeder
- Determine amounts offered and refused
- Weigh everything
37
Evaluate the cows (5)
- Body condition
- Cud chewing
- Manure evaluation
o ‘if soap you could lather up’
- Lameness
o Increased protein can contribute
- Sick cows
38
Evaluate cow environment (6)
- Can have a minor impact
- Free stalls
- Resting surfaces
- Flooring
- Ventilation
39
Additional testing (7): HERD TESTING
- Testing alone will never solve a problem
- Test results must be corroborated by other findings
- Rumen pH by rumenocentesis/stomach tube
- Blood tests for ketosis: energy balance
- Blood NEFAs on pre-fresh cows: energy balance
- Urinary pH: hypocalcemia
- Milk urea nitrogen (MUN): protein utilization
40
Diagnosis and make recommendations
- Individual data can contain error
- Make <3 total recommendations (ideally <1)
- Practical and specific
- Directly related to herd issues
- Related to herd’s goals
- Follow-up
