Download Reproduction

Bovine Reproduction
Prof. Dr. Kamil Naguib Mettias
Reproduction
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Evaluation
Is there a problem
Pinpoint the cause
Set achievable gools
TO :* Cull non breeding cows
* if over 10% …….serious problem in
Reproduction
The most two important factors
* Heat detection
* Conception rate
MEASURES OF REPRODUCTIVE EFFICIENCY IN CATTLE
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Age at first calving
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Days open
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First service conception rate
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Services per conception
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Calving interval
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Pregnancy rate
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Net calf crop
Days in Milk
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For 1 year avarage CI,DIM should be 160
– 170
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Every 1 day delay after 150 ADIM may
lead to a decrease of 80 gm of milk
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i.e in animal milking 25 Kg /d , in 200 days
the animal loose 50 x8= 4 Kg/day.
Days in Milk at First Breeding
70 days as a goal is good
* Herds with
=22 days over has no problem
=30 – 35 days over has one heat
missed in
50 %
=40 – 45 days over has one heat
missed /
cow or about 2 in 50 %
Days Open
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The most important bottom line indicator for
reproductive efficiency.
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Breeding cow at 1st heat may result in 55 D.O
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Optimum should be 90 – 110 days
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Cows over 115 D.O. have reproductive problem
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Calculation of D.O. With AI differ than with free
bull
Days open
Female fertility
Herd health
Management
Insemination
Breeding season
management
Herd health
Bull fertility
NET CALF CROP
days open
Breeding heifers
gestation
Calf survival
Dry Period Length
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Low Days = inadequate rest ,involution &
regeneration of udder = low Milk
More days =high feed cost with no milk
= Fat cow syndrome
= Low Milk production
It should be 45 – 55 days
Cows with low calving interval need long
period.
Cows with long calving interval need
short period.
Conception Rate
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Cows bred but not conceived increase D.O. by 21
days
S/C & CR are as one indicator for reproduction
performance
66% CR equal 1.5 S/C
It is affected by:
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Timing of Insemination
Semen Handling
Insemination Technique
Reproductive Tract Infection
Nutrition
Semen Quality
Heat Detection
Weather
Cow Fertility
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activity
teaser
observation
Low milk
progesterone
Body temperature
Cervical mucus
Missing Heat at Early Lactation Check
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Do all cows are o.k at reproductive Tract
Cystic ovaries !
Adequate nutrition
Spent time for detection
Are heat detection aids used
Is environment O.K to show oestrus
Culling policy
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Planned
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Infertility
Mastitis
Production
Not planned
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Milk yield
Age
Disease or Injury
Replacement Heifers
100 cows
30 replacement
20 culling
Control growth
Early calving
50 females
Nutrition
Environment
Breed
Age at
puberty
Body weight
Skeletal growth
Management
Infectious causes
Protozoal
Trichomonas
Neospora
Bacterial
Brucella
Campylobacter
Leptospira
Listeria
Salmonella
Viral
IBR
EVA
other
Fungal
Mycoses