Transcript Reproductive Efficiency in Beef Cows

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.
Biological Efficiency
Reproduction
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
Compact Calving: 90% calved in < 80 days
Low Culling Rate for infertility: < 5%.
Calving Interval: 365 day calving-to-calving
Shortening Postpartum interval
Improving
Reproductive
efficiency
Submission Rates
Conception Rates
Post-Partum Interval
Dairy Cows
Mean=26 days
(15-50 Days)
Beef Cows
Mean=55 days
(25-180 Day)
Postpartum reproduction - cattle
Aim to have a calf per cow
per year with peak lactation
to correspond with peak
grass growth
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
Main Factors Affecting Pregnancy Rate
Conception Rate
Pregnancy
Rate
Heat Detection Rate
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
Heat
70
Detection
Rate % 50
40
91
82
73
61
76
68
59
48
67
59
50
40
59
Heat Detection
Breeding
• Use of AI
• Heat detection
• Factors affecting conception rate
Primary Sign of Heat
Secondary Signs of Heat
• Sliming
•
•
•
•
•
•
•
Restlessness
Mounting activity
Trailing other cows
Bellowing
Mounting or dirt marks
Skin Marks
Met-oestrous bleeding
Mucous vaginal discharge
Chin resting
Factors affecting the
Expression of heat
Teagasc, Athenry
Results
No. Mounts
Effect of underfoot surface on number of mounts
received per heifer during standing heat.
40
40
48
30
20
20
0
Slats
Straw
Plastic Pasture
Underfoot surface
Effect of underfoot surface on duration of heat
Hours
20
14.2
15
10
14.7
12.3
8.6
5
0
Slats
Straw
Plastic
Underfoot surface
Pasture
No. Mounts
Effect of number of heifers in heat
simultaneously on the number of mounts
received heifer during standing heat.
40
40
20
29
17
0
1
2
3
No. Heifers in Heat Simultaneously
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
Pattern of heat Onset
% of cows first observed
at
7:00 10:00 13:00 16:00 23:00
47%
5%
5%
20% 20%
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
1
FEFC88F
Management Factors
Affecting Conception Rate
Reproductive Outcomes
British Friesian vs Holstein Friesian
British Friesian 1980
Holstein Friesian 2005
Late Embryo Mortality
7%
Calving rate
55%
Early
Embryo
Death 28%
10%
7%
Early
Calving rate
Embryo
40%
Death
43%
10+%
Fertilisation Failure
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
Concepion Rate (%)
Effect of AI timing on
Conception Rate
70
60
50
40
30
20
10
0
<6 h
6-12h
12-18h
18-24h
>24h
Interval from Detected Heat to AI
Conception Rate (%)
Effect of Calving Difficulty
on Conception Rate
60
40
20
0
1
2
3
4
5
6
Calving Difficulty Score
Long-term improvement of cow
fertility
• Use High EBI (Economic Breeding Index
sires)
Production: Yield fat +
Protein
• EBI
Reproduction: Calving interval
Cow survival
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.