Using Records to Troubleshoot Transition Cow Performance
Using Records to Troubleshoot Transition Cow Performance Greg Bethard, Ph.D. G&R Dairy Consulting, Inc. DRMS Blacksburg, VA email@example.com
Concepts• Benchmarking is a bad idea – Goal Setting and tracking makes a lot of sense• Pay attention to what is being measured and how it is measured• Economics trumps Biology
What is Transition Success?• Healthy Transition• Cows ready to get pregnant• Good start to lactation
What Are the Questions?• Important to formulate questions appropriate for the dairy• Strive to develop monitoring systems to answer questions quickly• Can’t afford to dig a hole it takes months to dig out of
Parity Differences• Must consider Lact=1 and Lact>1 separately in all transition metrics.• Issues are different, physiology is different, solutions are different.
Watch-outs• Repeats? – Activity Intervals in PCDART – Event Gaps in Dairy Comp• Too few cows• Ignoring Failures• Inconsistent diagnosis of disease
Watch-outs• Inaccurate milk weights (Test Day or parlor meter errors)• Dairy Culls• Misleading metrics
Misleading metrics• Peak Milk – Lagging, too much momentum, ignores failures, vague, imprecise• 1st Test Day Milk – Range error, Average error• Conception Rates• Fat test as proxy for health
Misleading metrics• Metrics with Variation – Too few cows…• Metrics with Bias – Ignoring animals…conception rate• Metrics with Momentum – Too much time..• Metrics with Lag – Too long to measure..
Variation• One number can greatly distort the results• Small herds are a big problem• Example: DA Rate – 10 cows calved in Jan – No DA’s (0%) – If 1 DA, increases to 10%• Solution: Add more time (calvings) to calculation
Transition Numbers with Variation…• Crude Rule of Thumb: Any number with <50 observations
Momentum• When too much time goes into the calculation, changes are difficult to detect, or take too long to detect.• Large changes can have a small impact on parameter
Transition Numbers with Momentum…• Peak Milk• Days Open• Calving Interval
Bias• Errors that occur when data is ignored or not used in the calculation• Using the wrong subset of cows, not including all of the cows, or not recording all of the data.
First service conception rate – A Biased Number• 2 breeding pens with 100 heifers each• Pen 1 – 50 heifers bred, 40 conceived – 80% 1st service conception rate• Pen 2 – 100 heifers bred, 60 conceived – 60% first service conception rate• 20 more pregnant heifers in #2
Transition Numbers with Bias…• 1st service Conc rate• Peak Milk• Days Open• Calving Interval
What Are Some QuestionsRelated to Transition Success?• Three Areas 1. Healthy Transition 2. Cows ready to get pregnant 3. Good start to lactation
Healthy Transition: Questions• How many cows are leaving in early lactation?• How many cows are getting sick?• Are cows eating?• What do they look like?
Healthy Transition Metrics I like….• 30 and 90 day cull rates – Cohort vs monthly – Goals • 3% and 7% for lact=1 • 5% and 10% for lact>1• DA, RP, MET, and MAST rate – Set goals for each dairy• % cows <40 DIM that are <50 lbs
Healthy TransitionMetrics to use with caution…• DMI for close-up• DMI for fresh pen
Healthy Transition Metrics I don’t like…• Fat percent of fresh cows• Fat:Protein ratios for fresh cows
Healthy Transition Future metrics?• BHB in milk• Body Weight in Fresh Cows?• Temp in Fresh cows?
Cows Ready to Get Pregnant: Questions• Are cows losing too much body condition?• Do cows have adequate body condition by 50 DIM?• How many cows are inseminated within 21 days of the VWP?• How many cows are pregnant within 21 days of the VWP?
Getting Cows Pregnant, Metrics I like…• 1st cycle Preg Rate for recent calvings• 1st cycle service rate for recent calvings• Scatter-plot of Days to 1st breeding vs. date• % Preg by 100 DIM and 150 DIM
Getting Fresh Cows Pregnant,Metrics to use with caution… • Conception rates – 1st service – By DIM • Conception rates are potentially biased, so you need to understand the bias
Getting Fresh Cows Pregnant, Metrics I don’t like…• Days Open• Calving Interval
Fresh Cow Milk: Questions• Are cows ramping up quickly in milk?• Do they milk during the peak window?• How many cows are “falling through the cracks”
Fresh Cow Milk Metrics I like…• Week 4 Milk• Week 8 milk• % over 100 lbs in herd• % of cows <40 DIM that are <50 lbs• 305ME projection at 2nd test day