6 – Feedlot Additives + Implants Flashcards
1
Q
What is the importance of processing of newly arrived cattle to the feedlot?
A
- First opportunity to have an affect on cattle’s health and performance in feedlot
- Busiest time of year at feedlot (but maybe not as seasonal when buying dairy cattle)
- Boring, repetitious task
- *priority
2
Q
Processing: general considerations
A
- Faster is NOT always better
- Handle them quietly and calmly
- Avoid injuries to both cattle and crew
- Restrain animals adequately in chute while processing
- Animal welfare guidelines
- *we are producing food NOT cattle=quality assurance
- Ideally within 12-24 hrs
- Delayed processing can result in disease ‘wrecks’
- ‘risk class specific’ and ‘feedlot specific’
o SLOWER FILL=GREATER RISK
3
Q
What are the components of a processing protocol?
A
- ID
- Vaccinations
- Early treatment/prevention of BRD: ‘metaphylaxis’
- Parasite control products
- Implanting
- Castration/dehorning (usually leave horns on)
- Quality assurance
o Injection sties/changing needles/withdrawal times, etc.
4
Q
What are the 3 common health issues in feedlot cattle?
A
- Bovine respiratory disease:
a. Mostly early in feed period - Lameness
a. Happen throughout - Nutritional related diseases (bloat, acidosis)
a. Mostly later in feed period
5
Q
Bovine respiratory disease
A
- MOST important disease concern in feedlot cattle
- Grouped into ‘risk categories’ based on ‘risk factors’
o Weaning
o Age/weight
o Mixing
o Transport
o Weather
o Gender
o Vaccination history
o Previous exposure to bunks and feed
6
Q
Ultra high risk calve
A
- Young
- Light weight
- “Holstein calves’
- Recently weaned
- No feed or vaccine history
- Not castrated
- Auction
- *likely to get metaphylaxis
7
Q
Low risk calves
A
- Yearling
- Higher weight
- Vaccinated
- Background and feed history
- Castrated
- Direct market
8
Q
BRD ‘stats’
A
- Morbidity and mortality dependent on combination of risk factors present
- Morbidity peaks within first 7-10days
o Can reach 35-50% - Case fatality: 5-10%
- *many arrive already incubating disease
9
Q
What are the challenges of BRD management?
A
- High risk animals are cheaper=makes for a more profitable return
o If can manage risk=can make more money
o Every $1/cwt reduction can afford an additional 1% death loss - Seasonal industry in Canada
- *level of mixing is significant and inevitable
- Majority of cow-calf producers sell calves DIRECTLY at weaning
- Many already incubating disease or become sick within a few days
- Many are in ‘witness protection program’ (we don’t know history)
10
Q
How is it being a seasonal industry in Canada?
A
- Fall run
- Many trailers arrive at one time
- Challenge to deal with processing within 24hrs of arrival and treating sick calves
- Hard to differentiate between sick and ‘homesick calf’
11
Q
What are some of the management strategies employed to deal with diseases?
A
- Vaccination on arrival
o Reduced disease, but not ideal - Pre-vaccination
- Preconditioning
12
Q
What is pre-vaccination?
A
- Specific sales and programs
- Does provide reduction in disease but doesn’t mitigate all risk factors
- Cow-calf producer should be paid more
- *hard to fill a whole pen though with those calves
13
Q
What is preconditioning?
A
- Step beyond pre-vaccination
o Weaned minimum 45d prior to sale
o Accustomed to eating from feedback
o Vaccinated
o Castrated and dehorned prior to weaning
o Treated for parasites at least 3 weeks prior to sale - *cow-calf producer benefits from increased sale weight and premium price
14
Q
What are some challenges with preconditioning?
A
- Low numbers of pre-conditioned calves available
- Price premiums not always enough for cow-calf producer
- Purchase prices vs. BRD risk dilemma
- *not as common anymore=just can’t fill enough pens
15
Q
What is metaphylaxis?
A
- Administration of injectable long acting microbial to control BRD upon arrival
- Treating early cases: those incubating
- Prophylaxis to cases that may develop in next few days
- *many label claims (ML or oxytetracycline
- 50% reduction in treatments and significant drops in mortality
- Resistance concerns
16
Q
What are the factors in choosing metaphylaxis?
A
- Expected disease risk (high, ultra high risk)
- Risk tolerance of owner
- Product efficacy based on clinical trial data
- Labour availability and skill
- Cost of treatment and cost of mortality
- Cost of metaphylaxis program
17
Q
Lameness: major contributors
A
- Bigger issue in dairy industry
- Major contributors
o *Foot rot
o Laminitis: due to high levels of grain
o Arthritis: mycoplasma bovis
o Toe-trip necrosis
o Digitial dermatitis - *1/3 of treatments=foot related
18
Q
What is toe tip necrosis?
A
- Unknown cause
- Occasionally occurs in outbreaks of feedlot calves from one source farm or auction yard
- Often severely lame after arrival at feedyard
- May be simply due to abrasion of toes during handling
- *treatment unrewarding
- Many animals eventually destroyed
19
Q
What foot and animals are more likely to get toe-tip necrosis?
A
- Hind feet
- Infection with environmental bacteria
- More common in excitable or wild animals
- Scrambling on rough footing
- Excessive wear on APICAL WHITE LINE
- Ascending infection
20
Q
Nutritional diseases and grain fed cattle: what can be added to help/minimize them?
A
- Finishing rations=90% grain
- *sequela of rumen acidosis
o Liver abscesses to post-venal caval thrombosis
o Laminitis
o Mycotic rumenitis - **ionophores are important additive to help with bloat and acidosis
21
Q
What are some examples of not managing nutrition well?
A
- Moving cattle to quickly up step-up program
- Delivering wrong ration to cattle
- Failing to keep feed available at all times
- Increasing amount of particular ration too quickly
22
Q
What’s ‘natural’ program in Canada?
A
- Not a specific label
o Likely implies minimal human intervention - Niche programs to limit use of
o Ionophores
o Antimicrobials
o Bet agonist
o Roughage level/grass fed programs
o Hormone implants
23
Q
Conventional grain fed vs. grass based diets
A
- Grain
o 3lbs/day
o 7lbs feed efficiency (1lb on animal)
o 171d to slaughter
o Lower feed and yardage costs - Grass
o 1lb/day
o 21lbs feed efficiency
o 488d to slaughter
o *need to get more money to actually make a profit or break even
24
Q
Identify the factors that have a major impact on profitability in the feeding industry
A
- Feed efficiency
o If change by 10%=43% change in profit - Cost of feeders and slaughter price: 20% change in profit each
- Death loses=much lower change in profit
25
Q
What are some feed additives?
A
- Ionophores
- Melengesterol acetate to heifers
- Antimicrobials
26
Q
Ionophores
A
- Widespread use
- Effect cell membrane of specific rumens and change flora of rumen
- Ex. monensin, salinomycin, alpharma
- *no prescription required if fed at label dosage and not in combo with other products
27
Q
What are the effects of ionophores?
A
- *Decrease feed intake, but improve feed efficiency and average daily gain
o Increased propionate
o Reduced acetate, methane, hydrogen ion and lactate production - Sloer rate of food passage
- Reduced protein degradation in rumen
- *aids in control of coccidiosis and decreases incidence of bloat
28
Q
Melengestrol acetate (MGA premix)
A
- 125x progesterone activity
o Prevents estrus
o ADG INCREASED and feed efficiency improved - Used in feedlot heifers
- Occasionally used to synchronize estrus in breeding
- NOT approved for concurrent use with hormone implants
- 24hr withdrawal prior to slaughter
29
Q
Antimicrobials as feed additives
A
- Can cause significant change in rumen flora resulting in growth benefits as well
- *growth promotion claims are all ELIMINATED
- Antimicrobial resistance=significant!
- *all added now require a vet feed prescription
- **Primary used is to feed to prevent liver abscess
30
Q
Liver abscess
A
- Accounts for 2% carcass weight
- Packing plant=not happy if condemned
o 16% condemnation rate
o Culled dairy cows: 24% - *severe ones can affect performance
o Decrease ADG and feed efficiency
o $50-60/head loss in affected animal
31
Q
What can be used to reduce liver abscesses? Most common
A
- Tylosin
o 40-70% reduction
o Improved ADG by 2%
o Improved feed efficiency by 2.6%
32
Q
What are some other antimicrobials used in feedlot rations?
A
- Tylosin
- Chlortetracycline
- Oxytetracycline
- Chlortetracycline + sulfamethazine
- *some tetracyclines used at higher doses to prevent H. somni or respiratory disease
33
Q
What are chlortetracycline + sulfamethazine used for?
A
- Prevention of foot rot
- Reduction of bloat
- Maintenance of weight grains during periods of stress: shipping/handling
