Transcript CAFRE Development Service

Level II Agricultural
Business Operations
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Cow needs to calve to produce milk
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Need to calve regularly to maintain yield
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Infertile cows need to be replaced
Fact 1: The average cow in Northern Ireland is
culled after completing just 3.5 lactations
Fact 2: Approximately 30% of cows are culled for
infertility
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Gestation Length:
Interval from conception to calving
Average: 280 days
Range:
270-290 days
Oestrous Cycle Length:
Interval from one heat to another
Average: 21 days
Range:
18-24 days
Calving Index:
Average interval between successive calvings for herd
Average: 420 days (from milk recording)
Range:
360-500 days+
Implications of Infertility
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Infertility
 semen usage
 intervention treatments
 spread of calving
 cull rates
 longevity
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Poor longevity
 replacement costs
Increased
financial
loss
Fertility Has Been Declining ... Why?
Fertility is influenced by a number of factors:
Breeding/Genetics
By breeding for
increased milk
production, have we
bred less fertile
cows?
Feeding/Management
Is infertility due to
larger herds and/or
poor nutrition of the
high-yielding
cow?
Assessment of Dairy Cow Fertility
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Which herd has the best fertility ... ?
Herd
A
B
Calving index Culled not-in-calf
(days)
(%)
370
390
15
5
Calving index prone to error/ misinterpretation
i.e. does not include cows culled for infertility
The True Cost of Infertility
Herd A
(365 days; 15%)
Calving Index Cost
5 days @ £3/cow/day x 100
cows
= £1,500
Replacement cost
15 cows @ £900/cow
=£13,500
TOTAL = £15,000
Herd B
(390 days; 5%)
Calving Index Cost
25 days @ £3/cow/day x 100
cows
= £7,500
Replacement cost
5 cows @ £900/cow
=£4,500
TOTAL = £12,000
Herds with lower calving intervals don’t
necessarily have a lower infertility cost !
Calving
Breeding/Conception
Pregnancy – 280 days
85 days
Calving
Calving
Breeding Conception
125 days
Pregnancy – 280 days
365 days
Calving
405
days
AI or Natural Service ... ?
AI Bull
Natural Service by Dairy Bull:
 Greater genetic progress
 Saves time in heat detection
 Multiple bulls - match bulls
to individual cows
 Conception rates – potentially
better
 Heat detection difficult and
time consuming
 Bull fertility – problems?
 AI technique – does it
affect your herd conception
rates?
 Bull may favour some cows
 Genetic progress limited
 Danger – especially indoors
How important are fertility and genetics in your herd?
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System – Are you high or low yielding?
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Calving pattern – is this important?
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Genetic progress – is this important?
Standing to be mounted
Head mounting
Lip-curling
Chin-resting
Sniffing
Secondary Signs of Heat
- Less Important Signs
Restlessness/Bellowing
Not standing to be
mounted
Licking other cows
Soliciting
Cajoling
Hair loss/dirt marks
Factors Affecting Heat
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Stage of oestrous cycle
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Number of cows in heat
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Presence of bull
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Housing – floor surface, layout, stocking density
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Stress - noise, change of routine
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Lameness and disease
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Nutrition – negative energy balance
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Weather & ground conditions at grass
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Knowledge of signs of heat
Duration of observation
◦ Minimum of 15 minutes/observation
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Timing of observation
◦ Minimum of three observations/day
◦ Observe when cows aren’t being disturbed
◦ Activity greatest late night/early morning
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Heat detection aids
Cow identification
Use of records
Heat Detection - Summary
To optimise your heat detection rate requires:
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Awareness of the secondary signs of heat and
their relative importance
Factors that affect a cows expression of heat
Management factors which affect your
observation of heat
Improved heat detection has more effect
in improving your overall herd fertility
than any other factor
Heat Detection Aids
1. Herd records
Paper records, Breeding boards, Computers
2. Teaser bull
3. Mount detectors:
Tailpaint, Pressure strips
4. Movement detectors:
Pedometers, Neck collars
Heat Detection Aids:
1) Herd Records
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Effective use of herd records is one of the most
beneficial ways to improve herd fertility
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Requires clear and unique cow identification
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Good records allow easy identification of non-cycling
cows and repeat breeding cows
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Records can be used to anticipate heats
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Simple paper-based herd recording systems are
inexpensive and effective
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Computer software often most effective, but
expensive and operators may require training
Heat Detection Aids:
1) Herd Records – Paper Records
Pocket diary
Calendar
21-day diary
Heat Detection Aids:
1) Herd Records – Paper Records
Cow
Date
Calved
Calving
Calf
Code Number
Treatment/
Remarks
Prebreeding Heats
Heat1
Heat2
Serve1
Bull1
Date of Service and Bull Used
Serve2 Bull2 Serve3 Bull3
Serve4
Bull4
Pregnancy
diagnosis
Drying off
Date
BCS Due Date
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Cow ID
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Date Calved
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Calving Code (1 = No assistance; 5 = Caesarean)
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Calf Number
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Prebreeding Heats – Heat 1, Heat 2
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Service Record – Date and Bull of Service 1, Service 2, etc
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Pregnancy Diagnosis – Date, Result
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Drying off – Date for drying off, Body Condition Score
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Due Date
Heat Detection Aids:
1) Herd Records – Breeding Boards
Heat Detection Aids:
1) Herd Records – Computer Action List
Heat Detection Aids:
2) Teaser Bull
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Bull calf that has been vasectomised
(rather than castrated)
Can still mount cow successfully but
ability to fertilise removed
Identifies cows on heat
However, he is a bull - can still be
dangerous
Advisable to have a new calf
vasectomised each year
Heat Detection Aids:
3) Mount Detectors - Tailpaint
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Cheap and effective, especially at grass
Specially formulated paints or bright
coloured emulsion paint
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Different colours can be used
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10 cm wide strip on cow tailhead
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For use on whole
herd or on cows not
yet pregnant
Cows should be
checked at each
milking
Heat Detection Aids:
3) Mount Detectors – Pressure Strips
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Pressure sensitive device glued onto
tail head
Pressure from mounting animal turns
detector from white to red
Built-in timing mechanism requires ~3
seconds pressure to activate
e.g. Kamar
Bovine Beacon
Heat Detection Aids:
4) Movement Detectors
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Step counting sensor (pedometer) worn on leg or
movement sensor on neck collar
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Both devices measure activity of each cow
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Assists detection of oestrus and health ailments
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Available as stand alone system or as part of modern
milking parlour system
e.g. Heat Time, DairyMaster,
GEA, DeLaval, Fullwood
Heat Detection Aids
- Summary
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Heat detection aids facilitate better heat detection
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Good record keeping: allows anticipation of heats
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Sophisticated technological aids are being
developed but simpler and cheaper aids may be
just as effective
Heat detection aids should not be a
replacement for time spent on heat detection !
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Voluntary Waiting Period:
- Period after calving during which cows are not
normally served
- Typically 42 days but can be higher in higher
yielding herds or lower in spring calving herds
Conception Rate:
- Proportion of services that lead to conception
or subsequent calving (calving rate)
CR%  No. of pregnant cows * 100
Total no. of services
Factors Affecting Conception Rate
- AI related factors
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Flask management
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Sire choice
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Bull fertility (AI or natural)
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Semen handling
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AI technique
Factors Affecting Conception Rate
- Management Factors
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Cow handling facilities
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Timing of AI (from onset of heat)
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Accuracy of heat detection
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Nutrition
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Interval from calving
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Disease status (BVD, Lepto, etc)
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Lameness
Practical Ways to Improve Fertility
Herd Health Status:
- Test for BVD, Lepto and Salmonella and vaccinate if
necessary
Sire Selection:
- Select bulls with a positive fertility score
When to Breed:
- Don’t serve cows while they are still losing weight
Number of Matings:
- Inseminate cows twice to dairy AI
- Subsequent services should be to a beef breed
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Good fertility management is essential
Extended calving intervals are estimated to cost
around £3/cow/day
Aim to improve fertility through better:
a) Heat detection – good herd records essential; use
heat detection aids if necessary
b) Conception rates – good AI technique and herd
management
Observe, record and monitor performance