Garrett R. Oetzel, DVM, MS School of Veterinary Medicine Food Animal Production Medicine Section

Transcription

1 Understanding and Preventing Ketosis Garrett R. Oetzel, DVM, MS School of Veterinary Medicine Food Animal Production Medicine Section

2 Ketosis

3 Individual Cow Testing for Ketosis Any sick cow between 2 and 30 DIM You need a method for testing

4 Cow-Level Testing for Ketosis Potential cowside tests urine, milk, or blood Sweet smell of breath acetone, other compounds only about 50% sensitive

5 Urine Ketones Ketostix test strip about $0.20 each have to stimulate urination dip and read within 10 seconds

6 Urine Ketones 40 to 60% will urinate catheters or vaginal exams are impractical touching strip to vaginal walls is inaccurate Need a plan for cows that do not urinate

7 Interpreting Urine Ketones Consider small (15 mg/dl) or greater to be ketosis Modest sensitivity and specificity 80% sensitive 95% specific

8 Other Cowside Ketone Tests - Milk Powders or tablets nitroprusside reaction 35% sensitive 98% specific Not recommended as sole test

9 Other Cowside Ketone Tests - Milk Ketotest test strip ~$2.50 per test dip and read 60 seconds later use 100 umol/l cut-point 83% sensitive 82% specific

10 Other Cowside Ketone Tests - Milk PortaBHB test strip ~$2.50 per test dip and read 60 seconds later use 100 umol/l cut-point 89% sensitive 80% specific

11 Other Cowside Ketone Tests - Blood Abbott Precision Xtra human hand-held system measures BHBA or glucose (different strips) $1.40 per BHBA strip <1 drop of whole blood Consider 1.2 mmol/l as ketosis >90% sensitive >95% specific

12 Blood Sample Collection Tail Vein NOT the milk vein Use 22 or 25 gauge needle with 1 or 3 ml syringe No special restraint

13 Using the Meter Insert strip into meter before applying blood

14 Ketosis Treatment If mild to moderate cases - give oral glucose precursors propylene glycol (PG) 300 ml (10 ounces) once daily glycerol (same dose)

15 If severe ketosis Treatment for Ketosis >3.0 mmol/l on the Precision Xtra meter nervous ketosis Give 250 ml 50% dextrose IV common dose is 500 ml (250 g glucose) this is an excessive dose of glucose a half bottle is better Follow with oral glucose precursor

16 Herd-Level Approach to Ketosis

17 Ketosis Prevalence vs. Incidence Incidence Total number of new cases Requires repeat sampling Prevalence How many cases present on one day Spot sampling Prevalence x 2 to 2.5 = Incidence

18 Subclinical Ketosis Increase risk of DA (3 to 19X greater risk) Decreased milk production (3 to 7% loss) Increased risk of culling in first 30 d (3X greater risk) Decreased reproductive performance (1.2 to 1.7X less likely to conceive at 1st breeding, unless on synch program)

19 Could We Develop a Better Herd Prevalence Tool?

20 Research Objective Collected blood samples on the day of milk test at AgSource member farms 550 cows and heifers 10 Holstein farms (2 Jersey farms) Laboratory BHBA assay was the gold standard Basic cow data (lactation number, days in milk) Milk sample analysis (fat, protein, BHBA, acetone, MUN)

21 Analysis Statistical analysis using multiple regression models Accuracy Overall ability to predict prevalence Strength of the model Sensitivity avoiding false negatives Specificity avoiding false positives

22 Separate Models Improved Accuracy Animal tested 1 st Lact 2 nd + Lact 5 to 11 DIM 12 to 20 DIM 5 to 11 DIM 12 to 20 DIM 5 to 11 DIM model 5 to 20 DIM model 5 to 11 DIM model 12 to 20 DIM model (R 2 = 0.74) (R 2 = 0.66) (R 2 = 0.57) (R 2 = 0.67) Accuracy: 96% 97% 88% 83%

23 How to Use KetoMonitor? Indicator of herd level prevalence Monthly milk test provide a management tool to guide decisions

24 Ketosis prevalence, % of cows How to Use KetoMonitor? 35% 30% 25% 20% 15% 10% 5% 0% Herd number

25 Multi-Tool Approach to Ketosis Testing Economic analysis of ketosis testing and treatment If prevalence is <7% test only sick cows If prevalence is 7 to 25% it is most economical to test cows 2 days/wk from 3 to 9 DIM If prevalence is >25%, it is most economical to consider blanket treatments What is the on-farm prevalence month to month?

26 Blood BHBA >=1.2 mmol/l, % 80% Summary of Weekly BHBA Monitoring (data pooled into 2-week intervals) 70% 60% 50% 40% 30% 20% 10% 0% 7/15/13 8/26/13 8/12/13 7/29/13 9/9/13 10/7/13 9/23/13 10/21/13 11/4/13 11/18/13 12/16/13 12/2/13 12/30/13 2/10/14 1/27/14 1/13/14 2/24/14 Date of BHBA Testing 3/24/14 3/10/14 4/21/14 4/17/14 5/5/14 5/19/14 6/30/14 6/16/14 6/2/14 7/7/14

27 Multi-Tool Approach Use the KetoMonitor to assess current herd prevalence Monitor prevalence compared to the target Monitor the impact of changes implemented Monitor shifts in on-farm prevalence Monitor shifts that have regional impacts Decide how intensively to test individual cows

28 Ketosis Prevalence, % Using KetoMonitor Results Use blood testing protocol for early diagnosis and treatment of ketosis Low ketosis prevalence justifies stopping blood testing Milk testing shows high ketosis prevalence; restart blood testing 10 Low ketosis prevalence justifies stopping blood detection Month

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31 KetoMonitor Statistics So Far Fresh Cows Herd Heifer Cow Tested Prevalence Prevalence Prevalence 46, % 7.2% 26.1% Highlights higher than desirable prevalence, primarily due to high prevalence in older cows

32 KetoMonitor Statistics So Far KM result Fresh Cows 30-d Culling Rate negative 37, % positive 8, % Analyzed KetoMonitor data for subsequent outcomes Cows predicted with ketosis by the KetoMonitor culling by 30 DIM was 3X greater

33 Causes of Herd Ketosis Overcrowding pre- and post-fresh cows Inadequate access to feed lack of bunk space lack of refusal Over-conditioned dry cows Excessive fat in the post-fresh diet Excessive pen moves in transition period long maternity pen or short post-fresh stays

34 Individual cows Ketosis Summary diagnose and treat promptly Herd level monitor herd prevalence use intensive testing and early treatment as indicated by herd prevalence

35 Ketosis Questions?