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Improving reproduction in NZ dairyherds
Scott McDougall, Tom Brownlie, Melvin de Boer, Chris Compton
Cognosco, Anexa Animal Health, Morrinsville, New Zealandsmcdoug@ahc.co.nz
CalvingPattern
HeiferMgt.
Bodycondition
&nutrition
HeatDetection
Genetics
& ABPractices Bull
Mgt.
CowHealth
Dealingwithnon-
cyclers
Herd Fertility• Is like a cake
• Herd Managementareas
• - 8 ingredients
Key areas of fertility management
• Varies among farms & often multifactorial
• So whole farms systems approach
– InCalf used in 10-15% of herds nationally?
• However for many farms the key issues are
– Poor heifer growth
– Poor calving spread
– Low BCS
– Peripartum and uterine disease
– Non cycling cows
So what are approaches?
• Specific interventions include:
– Non cycler diagnosis & treatment
– Endometritis diagnosis & treatment
– Managing calving patterns
• Mating length
• Culling
• Synchrony
• Induction
Non cycling cows
• Not detected in oestrus before matingstart date (or day -10)
• Associated with
– Younger cows
– Friesians
– Late calving
– Disease around calving
– Low BCS
Cumulative % pregnant bystatus before breeding start
P<0.001 AA vs. others;Data from McDougall & Compton JDSc 2005
Economic impact($NZ/400 cows)
Actual (%) Difference (%)
Group $/400 cows6 weekInCalf MT
6 weekInCalf MT
AA -20,475 53.4 15.5 10.1 -3.6Cycler 0 63.4 11.8
At NZ national level = $40 million loss/annum
How to deal with ND0/AAcows?
Management ofNDO/AA cows
• Prevention
– Genetics
– Breed
– Dry off decisions
– Prepartum nutritionalmanagement
• Macro & micro
• BCS effects
– Milking frequency
– Peripartum cowdisease management
• Cure
– ‘Bull’ effects
– Once a day milking
– ‘Split off’
– Hormonal
Breed/genetics approaches
• Breed
– 10% reduction inNDO by switchingbreeds
– Major farm systemseffects
• Genetics– h2 of calving to 1st ovulation
(P4) ~ 15-30%
– In NZ breeding objectivesbut using PSM-1st breeding(h2 = 6%; Grosshans et al 1997)
– Slow (10 years +) &expensive?
– Use of clinical phenotypes(scan/palpation?) as proxyfor P4
– Specific SNP’s?
Separate grazing and P4response
Control Split P4+ODB
Split+P4+ODB
Number of cows 172 177 168 159
Inseminated by 28 days 55% 46% 94%* 87%*
Conceived to 1st AB 40% 33% 36% 27%*
Pregnant by 28 days 26% 19%* 42%* 31%
* P<0.05 vs. control; Clark et al 1999; NZSAP 59:55-57
Treating non cyclers with once aday milking and/or P4+ODB
Con OAD P4+
ODB
P4+ODB+OAD
No. cows 110 106 107 94
Submission D21 66% 77% 94% 98%
Con rate to 1st serve 54% 47% 47% 34%
Preg 3 wks 38% 42% 53% 45%
PSM-con (days) 20 (±2) 18 (±2) 12 (±2) 14 (±2)
Empty 12% 14% 5% 12%
Main effect of P4+ODB for Sub D21 + PSM-Con p<0.05 for P4+ODB;Rhodes et al 1998; NZSAP
Milk yield difference (TAD-OAD) = 0.27 kg MS/cow/day
Bull effects?• Beef heifers and cows = +ve effects
(Berardinelli et al 2008)No bull Bull P-value
No. heifers 67 94% cycling at PSM-7 31.3 85.1 <0.001% in oestrus after PG 49.3 52.1 0.86% bred to timed AI 67.2 62.8 0.67% con rate at time AI 35.6 57.6 <0.05% preg rate 51.5 66.3 <0.05
Hormonal treatment ofNDO/AA cows
• Combination of GPG (‘Ovsynch’) +progesterone increase pregnancy ratesover GPG alone or no treatment
• This effect is consistent across CL+ andCL-ve NDO cows
• 1st service conception rate NSDbetween control and treated cows
• Economic
McDougall JDSc 2010
Mean (SE) interval (days) fromstart of breeding to conception
CL status p<0.001; Group p=0.03; group by CL status p>0.1Columns within CL status with different superscripts differ at p<0.05
Diagnosing and treating cowswith uterine or ovarian disease
• Metritis
• Endometritis
• Pyometra
• Ovarian cysts
Diagnosis
• Metritis
– <21 days after calving
– Systemically ill (hot, off feed, smelly &bloody discharge)
• Endometritis
– >20 days calved
– Usually not systemically ill
– Purulent material in vagina &/or uterus
Does peripartum diseasematter?
McDougall 2001 NZ Vet J 49: 60-67
Risk factors for uterineinfection
• Difficult calving
– Bull calves
– Caesarean section
– Heifers
• Twins
• Retained placenta
• Displacedabomasum
• Vulval angle
• High milk protein %
• Inadequate transition
– ↓ BCS
– ↓ Ca
– ↓ Mg
– ↑ BOH, NEFA
– ↓ Albumin
– ↑ GDH, AST
■= High PMN% □= Low PMN%
Burke et al 2011
Diagnosis of uterine infection
Metricheck?
Vaginoscopy?
Cytology?• Visual assessment?• Palpation?• Scanning?• Bacteriology?• Histopathology?
Score 1 Score 2 Score 3
Score 4 Score 5
McDougall et al 2007 ARS
Frequency of score
McDougall et al 2007 ARS
Median interval (d) toconception
* *
*
*
McDougall et al 2007 ARS
% of cows with uterineinfections by days calved
Sheldon & Dobson Theriogenology 2004
vs.
PGF2 Antibiotics
Intrauterine antibiotic treatmentof cows with a history of RFM
Con Met Diff P
no. cases 132 136
CIDR'ed (%) 15.2 16.9 1.8
Sub D28 (%) 87.9 94.9 7.0
Con S1 (%) 40.9 50.0 9.1
Preg D28 (%) 45.5 57.4 11.9 **
Preg D56 (%) 78.4 86.7 8.3 **
Days to conceive 33 20 -13 *
MT (%) 9.1 7.4 -1.7
McDougall NZVJ 2001
Effect of antibiotic treatment ofendometritis (metricheck +ve) cows
(Runciman et al 2009)
RR(6 wk) = 1.50 (95%CI = 1.10-2.06;RR(21wk) = 1.15 (95%CI =0.98-1.36)
Effect of PG at days 35 and 49after calving on reproductive
performance
No effect of PG in High or Low risk of uterine disease,No effect of P4 status (Dubuc et al 2011 JDS)
Manipulating calving patterns
• Calving pattern important determinant of% NDO, conception rate, 6-week in-calfrate, MT rate
• Pattern can be manipulated by– Synchronisation and/or early mating of the heifers
– Synchrony of cows
– Use of ‘short gestation’ bulls
– Shortening the duration of the breeding period
– Strategic culling of late calvers
– Induction of parturition
Heifer synchrony
• Calve heifers ahead of herds: moredays before start of breeding (fewerNDO heifers)
• AIso shorten generation interval
Treatment GroupFirst service
conception rate (%)
Double-PG 119/248 ab (48)
GPG + P4 180/383 a (47)
Cosynch + P4 213/374 b (57)
Conception rate to firstService (AB)
Pregnancy rate to firstService (AB)
(i.e. # preg/all synchronised)
Treatment Group In-calf to AB (%)
Double-PG 119/380 a (31)
GPG + P4 180/383 b (47)
Cosynch + P4 213/374 c (57)
Pregnancy rates
Treatment GroupDifference indays in milk
Double-PG 0
GPG + P4 3.9
Cosynch 6.4
Cow synchrony: ‘why wait’ PGsystems
Blue tail paint
-21 +5-2-14
PGGreens
PGYellows
-7
Green tailpaint
Yellow tailpaint
-35
Redtail
paint
-9
Treat non-cyclers
0(PSM)
Progesterone-based whole-herd synchronysystems with AI on detection
Xu and Burton, 2000 JDS 83:471-6
0-10 -3Days from start of breeding
GnRH PG
Synchronized:
Control: AI on detection
-2
(2)
(1)
7 days
8 days
AI(on detection)
-9
8D P4 7D P4
Con Synch Con Synch P
No. 512 515 504 509
Sub d6 33 93 32 92 *
Con S1 63 57 63 65
Preg AI* 82 86 80 85 *
MT 5 4 5 5
Days to con 22 14 21 14 *
Synchrony results (%) of cows
* 5 -7 weeks; Xu and Burton, 2000 JDS 83:471-6
Induction of parturition
• Cows due to calve late in calvingperiods can be induced to calve earlier
– Use analogue of the normal signal forcalving (corticosteriods)
• Managed under a memorandum ofunderstanding between
– Vets
– Processors
– Farmer organisations (DairyNZ, Fed Farmers)
• Specific cow & herd requirements
• Stated industry goal is to reduce use ofinduction
• Targets set (maximum % of cows withina herd):
– 15% in 2010/11
– 8% in 2011/12
– 4% in 2012/13
– ? in 2013/14
• Technically induction works
– i.e. calving date advanced by 6 to 8 weeksfor the majority of cows
– More days in milk, longer interval to start ofbreeding = fewer NDO cows
• Potential issues
– Immunosupressant: increased risk ofdisease?
– Calves non-viable: euthanasia issues
P4
PG
*Planned start of mating
•BCS, nutrition &trace elements•Apply tailpaint allcows•Examine cows withperipartum disease•‘Pick-up’ bullschecked
•Examine “Not detectedin oestrus” cows•BCS•Tailpaint
Pregnancydiagnosis(manual or US)
GnRH
-85
NZ breeding programmes
•BCS•Review performance•Modify as required
STAI
Calving (80 d)
-1-2-10-35 77-84 ~35-56days after
bull removal
Bull (50-80 d )
0=PSM*
AI (28-42 d)
“Planned start of calving:PSC”
Conclusions
• Reproductive performance in NZ isdeclining
• Introduction of InCalf may help: focuson prevention & systems approach
• Usually multifactorial approach required
• Common issues include poor calvingspread, non cycling cows, peripartumdisease , low BCS
• Not detected in oestrus cows are asignificant cost to industry
• Multiple approaches to prevention /treatment
– Hormonal treatment remain mostconsistent/effective
– Ovsynch + P4 most effective and cost-effective
• Preventative strategies remain unproven
– Nutritional strategies for pasture fed cattle unclear
• Postpartum anovulatory interval has higherheritability than other reproductive measures
– Possible basis for selection
– Cost of phenotype?
• Use of proxies such as submission rate, CL status at vetexam?
• Peripartum disease increases risk of uterineinfection/inflammation which in turndepresses fertility
• The metricheck device has improved ability todetected infected cows
• Intrauterine antibiotics are the most effectivecurrent treatment
• Induction is being phased out
Thank you
Questions?
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