reproductive management of dairy cows with particular reference to organic systems michael g diskin...
TRANSCRIPT
Reproductive Management of Dairy Cows with Particular Reference to Organic Systems
Michael G Diskin & Frank Kelly
Animal Production Research Centre, Teagasc,
Mellows Campus, Athenry, Co. Galway.
Holstein-Fresian cattle
Grolier Electronic Publishing, Inc.
Reproduction
Biological Efficiency
Production Efficiency
Profitability
Overall Requirements for Organic Milk Production Systems
• Compact seasonal calving patterns,
• Maximal production from grazed grass,
• Low involuntary culling rates
• Continuous genetic improvement of the herd
Reproductive Targets
Low Culling Rate for infertility: < 5%.
Calving Interval: 365 day calving-to-calving.
Compact Calving: 90% calved in < 80 days
Aim to have a calf per cow
per year with peak lactation
to correspond with peak
grass growth
Postpartum reproduction - cattle
To Ensure Rapid Onset of Oestrous Cycles Post Calving
• Cows calve in a moderate BCS
• Ensure high DM intakes post calving & minimise BCS loss – Minimise Negative Energy Balance (NEB)
• Calve heifers early
• Consistently use Sire with strongly positive sub indices for Fertility
The Effect of Different Heat Detection and Conception Rate on % of Herd Pregnant at 90 Days After Onset of Breeding Season
Conception rate
60 50 40 30
90 96 91 83 71
70 91 82 73 61
50 76 68 59 48
HeatDetectionRate %
40 67 59 50 4059
Secondary Signs of Heat• Sliming
• Restlessness
• Mounting activity
• Trailing other cows
• Bellowing
• Mounting or dirt marks
• Skin Marks
• Met-oestrous bleeding
Effect of underfoot surface on number of mounts received per heifer during standing heat.
2030
4048
0
20
40
Slats Straw Plastic Pasture
Underfoot surface
No.
Mou
nts
Effect of underfoot surface on duration of heat
8.6
14.212.3
14.7
0
5
10
15
20
Slats Straw Plastic Pasture
Underfoot surface
Hou
rs
Effect of number of heifers in heat simultaneously on the number of mounts
received heifer during standing heat.
17
29
40
0
20
40
1 2 3
No. Heifers in Heat Simultaneously
No
. Mo
un
ts
Duration of Standing Heat
• Average = 8 -14 hours (Range 3-30 hours)
• Similar for cows and heifers
• Range 3-30 hours
• Interruptions in standing activity
Improving heat detection
• Commitment and understanding heat behaviour
• Tail paint
• Oestrus Alert Patches
• Teaser Bull
Teaser Bulls• Use yearling bull• Vasectomise 6 weeks before intended
use• Fit with chin-ball 2-3 weeks before
introduction to herd• Castrate or sell at end of breeding
season
Reproductive Outcomes British Friesian vs Holstein Friesian
10%
10+%
Calving rate55%
Calving rate40%
EarlyEmbryo Death 28% Early
Embryo Death 43%
Fertilisation Failure
Late Embryo Mortality 7% 7%
British Friesian 1980 Holstein Friesian 2005
Change in BCS and conception rate
• 10-15% decline in conception for each 0.5 unit change in BCS between calving and AI.
Effect of Calving to Service Interval on Conception Rate
Calving-to-Service Interval(Days)
1-20 21-40 41-60 61-80 >80
CR% 0 30 54 63 72
Effect of AI timing on Conception Rate
010203040506070
<6 h 6-12h 12-18h 18-24h >24h
Interval from Detected Heat to AI
Con
cepi
on R
ate
(%)
Effect of Calving Difficulty on Conception Rate
0
20
40
60
1 2 3 4 5 6
Calving Difficulty Score
Con
cep
tion
Rat
e (%
)
Long-term improvement of cow fertility
• Use High EBI (Economic Breeding Index sires)
• EBI Reproduction: Calving interval
Cow survival
Production: Yield fat + Protein
Summary -1
Calve cows in a moderate BCS Minimise BCS loss in early lactation. Have cows gaining in BCS at breeding. Have heifers well-grown (350-380 kg)
at 15 months. Breed to calve early. Minimise the risk of calving difficulty .
Summary -2
Increase submission rates by paying particular attention to heat detection.
Use tail-paint. Carry out pre-breeding heat detection.
Ensure that the semen used is of high fertility Use AI Sires with negative values for calving
interval and positive values for survival Correct AI technique Inseminate cows at the correct time.