OVC Research Update Todd Duffield, David Kelton, Stephen LeBlanc, - - PowerPoint PPT Presentation

OVC Research Update

Todd Duffield, David Kelton, Stephen LeBlanc, David Renaud, Charlotte Winder

Sampling of projects areas

• Managing and transporting male dairy calves
• Ketosis monitoring and management
• Knee and hock injuries
• Heat detection – activity monitors
• Automated milk feeders
• Pain control for disbudding
• Evaluating antibiotics for udder health

Identifying high‐risk calves upon arrival at veal farms

Identifying high‐risk calves

Navel Score Dehydration Score Source Body Weight Cough Score Sunken Flank IgG Status Cholesterol Level

Renaud et al., 2018

Selective antimicrobial strategy

TREATMENT ROOM:

Selective therapy by risk

Risk: Normal Low Risk High Risk

Screening

CONTROL ROOM:

Group metaphylaxis Screening

Selective antimicrobial strategy

• Morbidity (First 14 days)
• Mortality (First 14 days)

Blanket tx Selective tx Untreated 93% (506) 91% (444) Treated 7% (38) 9% (44) Blanket tx Selective tx Survived 99% (537) 98% (477) Died 1% (7) 2% (11)

20% of calves treated

Transportation of Male Dairy Calves

Transportation of Calves

• New regulations
• Research plan
• Evaluate the effect that transportation time, condition, and distance on health
• Explore impact of age at transport on health
• Stay tuned for more information!

Ketosis

Ketone Testing

• Daily testing in blood and milk

Median time to ketosis was 5 DIM (95% CI: 5 – 7 DIM) in

blood

Median time to ketosis was 7 DIM (95% CI: 6 – 11 DIM) in milk

Reducing milking frequency as an adjunct treatment for ketosis

0.2 0.4 0.6 0.8 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

Proportion of Cows with Ketosis Day of Trial

ODM TDM 0.00003% 32.2%

Once‐daily milking (ODM) more effectively resolved ketosis than twice‐daily milking (TDM) for primiparous cows

ODM heifers were more likely to resolve ketosis than TDM heifers (P<0.01)

Once‐daily milking (ODM) more effectively resolved ketosis than twice‐daily milking (TDM) for multiparous cows

0.2 0.4 0.6 0.8 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

Proportion of Cows with Ketosis Day of Trial

ODM TDM 27.3% 60.3%

ODM cows were more likely to resolve ketosis than TDM cows (P<0.05)

10 20 30 40 50 60 70

1 2 3

Percentage of cows Number of additional PG treatments

ODM TDM

Percentage of cows that required additional 5 d propylene glycol treatments

* Summary of data only

32 34 36 38 40 42 44 46 48 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Energy‐corrected milk yield (kg) Time from start of treatment (weeks)

ODM TDM

Two weeks of ODM caused short and long term energy‐ corrected milk (ECM) losses

ECM is corrected for 3.5% fat & 3.2% protein (Bernard, 1997)

ODM cows produced ~25% less ECM during treatment (wk 1 & 2) (P <0.001) ODM cows produced ~14% less ECM after treatment (wk 3‐15) (P < 0.05) ODM cows produced ~6% less ECM (P=0.043)

Conclusions

• Reducing milking frequency to 1x/day for two weeks was more effective at

treating ketosis and improving indicators of energy balance than treating with propylene glycol alone

• 1.5x lower BHB for heifers, 2.1x lower BHB for cows by d 15
• No difference in DMI  TDM energy demands far exceeded intake
• However 2 weeks of ODM caused reductions in milk

(and ECM) yield lasting up to 13 weeks post‐treatment

• 18% ↓ milk, 14% ↓ ECM
• Tendency for an increased linear score

The characterization and resolution of hock and knee injuries on dairy cattle

Funding provided by: Dairy Farmers of Ontario OMAFRA Alliance

• A. M. Armstrong, T.F. Duffield, D.B. Haley, and D.F. Kelton

This slide has many

Key findings & research implications

• Based on our results, hock and knee injuries do heal depending on their

severity and housing environment.

• Cows transitioned to mattresses showed less healing compared to those

transitioned to sand and pasture

• Cows with chronic major swelling (Score of 3) do not show signs of healing
• Knee injury scores of 2 healed regardless of stall base
• Implications:
• Cows with hock injury Score 2 will heal in about 2 months
• nce moved into more ‘cow friendly’ environments
• Realistic timelines for re‐assessment of corrective action plans is 2 to 3 months.

Tie-stall to pasture– 7 week difference

• Based on our results, some observed lameness may be due to

hock and knee injuries

• A proportion of cows did not have hoof lesions but had abnormal

locomotion – lameness is also a result of the environment and other injuries (hock & knee)

• Cows with both knees injured were 3 times more likely to be mildly lame

(p=0.003; 95% CI: 1.4‐5.7)

• Cows with both hocks injured were 3 times more likely to be obviously

lame (p=0.05; 95% CI: 1.0‐10) Implications:

• Important to recognize that not all cows with an abnormal locomotion

score have hoof lesions.

• Presence of moderate to severe hock and knee injuries do cause some

cows to exhibit impaired locomotion.

Key findings & research implications

• 27% of freestall herds in

Canada using activity meters in 2015

• Large field trials and

herd surveys to assess how well activity monitors work as tools for herd management

1400 AI on 4 farms

Leroy et al 2018

• J. Dairy Sci.

101:1638–1647

• AAM needs to be complemented with

timed AI to set limits on time to 1st and repeat AI

• Randomized controlled trial 849 1st AI, 2

herds

• Double Ovsynch at 85 DIM vs. activity only

50-75 DIM, then Ovsynch

• On average, AAM can achieve similar

21-d pregnancy rate and economic performance to TAI-based management but this varies among herds

Denis‐Robichaud et al 2018

• J. Dairy Sci. 101:624–636

• 17 farms
• Each farm was visited 4

times, seasonally, over 1 year

• Calf, pen, feeder, and farm

data

Field study of calf health with AMF

Medrano‐Galarza et al 2018

• J. Dairy Sci. 101:2293–2308

Controlled trial – Age of introduction to group with AMF

• 60 calves
• Elora Dairy Research facility
• Move to group at 1 or 5 days
• ld
• Bottle-fed while in individual

pen

• Measured time spent feeding

and training, growth, health

Medrano‐Galarza 2018

• J. Dairy Sci.

101:9371–9384

• Early introduction:

– Took longer to learn to use the AMF (65 vs. 30 h) – Did not increase the risk of diarrhea, but higher odds

• f severe diarrhea at a younger age

– Decreased milk intake during the 1st week of life – Did not affect growth

• Early introduction can be successful:

– Reduce labour without affecting growth – Trade-offs between labour and calf health

• Our suggestion is to move calves onto AMF at

~ 5 d old

Controlled trial – Age of introduction to group with AMF

26

2019 – 2021

• Identify markers using data collected from AMF to:

‐ Identify calves with disease earlier ‐ Identify farms with high disease burdens

• Validate new technology for use on/with AMF systems in the future

‐ E.g. pedometers, drinking aggression

27

• Pain control for caustic paste (2018)
• Benefits of xylazine sedation? (2018-2019)
• Wound healing and calf nutrition (2019-2020)
• Exploring barriers to adoption in ON and WI (2020-2021)

29

Previous research has shown local anesthesia + NSAID to be best practice for paste, but no studies have examined use in calves < 7 days of age

 Calves given a cornual nerve block had fewer pain behaviours

 Calves given a cornual nerve block had reduced pressure sensitivity

 Sham disbudded calves drank sooner following pen entry

Comparative efficacy of antibiotics for udder health

33

What is the comparative efficacy of intramammary lactating therapy antibiotics on clinical cure for clinical mastitis?

f(6) aa(2) ac(1) ae(2) af(1) ag(1) ah(2) ao(2) b(1) c(4) d(4) e(1) a(2) g(3) h(2) m(2)

• (1)

q(5) r(1) x(2) y(2) z(4)

Clinical cure

Penicillin Ceftiofur x 2d Ceftiofur x 8d Penicillin/aminoglycoside Ceftiofur x 3-5d Cephaprin Cloxacillin Amoxicillin NTC

Clinical cure

What is the comparative efficacy of intramammary dry cow antibiotics for prevention of new intramammary infection?

NAC(21) CLOX(15) ERY(1) GENT(1) CEPH(7) NOVO(2) PCS(2) PEN_AG(9) QUIN(2) TIL(3) TS(2) TS_CEPH(4) TS_CLOX(4) TS_CT(1) TS_PEN_AG(2) TS_TYL(1) TYL(2)

New IMI

1 6 12 17 Ranking NAC(21) ERY(1) NOVO(2) TYL(2) TIL(3) CLOX(15) QUIN(2) PEN_AG(9) GENT(1) CEPH(7) 15.36(13.00, 17.00) 15.35( 5.00, 17.00) 13.69( 5.00, 17.00) 11.91( 4.00, 17.00) 11.21( 4.00, 16.00) 10.75( 6.00, 14.00) 10.11( 2.00, 16.00) 8.05( 3.00, 13.00) 7.83( 1.00, 16.00) 6.66( 2.00, 12.00)

Cephalosporin Gentamycin Penicillin/aminoglycoside Quinalones Cloxacillin Tilmicosin Tylosin Novobiocin Erythromycin Non‐active or non‐ treated control

New IMI

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Despite a large volume of research, we don’t have good data to know products’ relative efficacy In deciding whether to treat, decide on cow-factors <- most important! Which treatment to pick? <- selection should be based on other factors