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?