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 Sunken Flank Body Weight Navel Score Cholesterol IgG Status Level Dehydration Source Score Cough Score Renaud et al., 2018

Selective antimicrobial strategy Risk: Normal Low Risk Screening Screening High Risk TREATMENT ROOM: CONTROL ROOM: Group metaphylaxis Selective therapy by risk

Selective antimicrobial strategy 20% of calves treated Blanket tx Selective tx • Morbidity (First 14 days) Untreated 93% (506) 91% (444) Treated 7% (38) 9% (44) • Mortality (First 14 days) Blanket tx Selective tx Survived 99% (537) 98% (477) Died 1% (7) 2% (11)

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 Median time to ketosis was 7 DIM ketosis was 5 DIM (95% CI: 6 – 11 DIM) (95% CI: 5 – 7 DIM) in in milk blood

Reducing milking frequency as an adjunct treatment for ketosis

Once‐daily milking (ODM) more effectively resolved ketosis than twice‐daily milking (TDM) for primiparous cows 1 Proportion of Cows with Ketosis 0.8 ODM heifers were more likely to resolve ketosis than TDM heifers ( P <0.01) 0.6 32.2% 0.4 0.2 0.00003% 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 Day of Trial ODM TDM

Once‐daily milking (ODM) more effectively resolved ketosis than twice‐daily milking (TDM) for multiparous cows 1 ODM cows were more likely to resolve ketosis than TDM cows ( P <0.05) Proportion of Cows with Ketosis 0.8 60.3% 0.6 27.3% 0.4 0.2 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 Day of Trial ODM TDM

Percentage of cows that required additional 5 d propylene glycol treatments 70 60 Percentage of cows 50 40 30 20 10 0 1 2 3 Number of additional PG treatments ODM TDM * Summary of data only

Two weeks of ODM caused short and long term energy‐ corrected milk (ECM) losses ODM cows produced ~14% less ECM 48 after treatment (wk 3‐15) ( P < 0.05) 46 Energy‐corrected milk yield (kg) 44 42 ODM cows produced ~25% less ECM during treatment 40 (wk 1 & 2) ( P <0.001) 38 ODM cows produced 36 ~6% less ECM ( P =0.043) 34 32 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Time from start of treatment (weeks) ODM TDM ECM is corrected for 3.5% fat & 3.2% protein (Bernard, 1997)

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

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 This slide has many 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 once 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

Key findings & research implications  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.

1400 AI on 4 farms • 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 Leroy et al 2018 J. Dairy Sci. 101:1638–1647

• AAM needs to be complemented with timed AI to set limits on time to 1 st and repeat AI • Randomized controlled trial 849 1 st 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

Field study of calf health with AMF • 17 farms • Each farm was visited 4 times, seasonally, over 1 year • Calf, pen, feeder, and farm data

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 old • Bottle-fed while in individual pen • Measured time spent feeding and training, growth, health Medrano‐Galarza 2018 J. Dairy Sci. 101:9371–9384

Controlled trial – Age of introduction to group with AMF • Early introduction: – Took longer to learn to use the AMF (65 vs. 30 h) – Did not increase the risk of diarrhea, but higher odds of severe diarrhea at a younger age – Decreased milk intake during the 1 st 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

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 26

- 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) 27

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 29

 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?

Clinical cure f(6) z(4) aa(2) y(2) ac(1) x(2) ae(2) af(1) r(1) q(5) ag(1) o(1) ah(2) ao(2) m(2) h(2) b(1) g(3) c(4) a(2) d(4) e(1)

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

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

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

New IMI Cephalosporin CEPH(7) 6.66( 2.00, 12.00) Gentamycin GENT(1) 7.83( 1.00, 16.00) Penicillin/aminoglycoside PEN_AG(9) 8.05( 3.00, 13.00) Quinalones QUIN(2) 10.11( 2.00, 16.00) CLOX(15) 10.75( 6.00, 14.00) Cloxacillin Tilmicosin TIL(3) 11.21( 4.00, 16.00) Tylosin TYL(2) 11.91( 4.00, 17.00) Novobiocin NOVO(2) 13.69( 5.00, 17.00) Erythromycin ERY(1) 15.35( 5.00, 17.00) Non‐active or non‐ NAC(21) 15.36(13.00, 17.00) treated control 1 6 12 17 Ranking

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 42