Investigating Under-performance in Dairy Herds Flashcards
What age should a heifer first calf and why?
24 months old as if this target isn’t achieved then it is difficult for the cow to catch up in productivity over her life span
When should first service of a heifer be?
14-15 months old
What should the weight and height of a heifer be at first service?
375kg
132cm
Why might weight and height be a better measure for when first service should occur?
To reduce dystocia
To reduce overweight/underweight first time calvers
What are the difficulties of height and weight measurements of heifers?
Measuring every 6 weeks is hard to do as requires time
Requires an investment in infrastructure
Consistency is key - always measure at same point (withers/pelvis)
What is the calving score?
0 = no hand touches calf 1 = hand touches but no rope 2 = rope is used with a gentle pull 3 = rope is used and a hard pull 4 = Caesarian section
What is live birth rate?
The percentage of calves born which are alive and survive for 24 hours
What should be the target live birth rate?
97% in cows and 92% in heifers
How should records be analysed?
Heifers vs cows
By bull/sire
By sex of calf
By operator
What should be done if there seems to be problems around calvings?
Suggest training on routine calvings as discussions can reveal a problem that staff thought was too stupid to ask about
What should be done with the calf at birth?
Navel should be dipped immediately in 7% iodine and totally immerse with this repeated again at 24 hours
How much colostrum should a new born calf intake?
6 litres in first 12 hours of 6 pints in the first 6 hours
When is absorption of colostrum best?
When suckled from the dam or when consumed in the presence of the dam
What is the human intervention schedule for colostrum management?
2 litres in first hour, 2 litres in 6 hours, 2 litres in next 6 hours
How should colostrum be collected?
From the first and second milkings into a stainless steel bucket which is checked for quality with a colostrometer
How should colostrum be stored?
In the fridge at 4C for 24 hours or freeze immediately and thaw in warm water
What objective measure can be used to assess colostrum intakes?
Blood sample 2-7 days using clotted red top tube for serum
Send to lab for zinc sulphate turbidity test or total protein
Use a refractometer = 55g/l
How is calf milk replacer used?
For 12.5% feed 2 litres twice a day (125x2x2 = 0.5 kg/day)
For 15% feed 2.5 litres twice a day (150x2.5x2 = 0.75 kg/day)
What is the objective of concentrate feeding?
Maximise calf concentrate intake by the time of weaning and when weaning occurs must already be eating sufficient concentrate
What is a good example of concentrate feeding?
Keep concentrate fresh, changing 2x a day with guideline of 1kg per day intake at weaning
What should be the approach to calf diarrhoea?
Look at environment, feeding and immune status of calves
What is the calving index target?
365 days interfere at >380 days
What is the earliest service date?
50 days and interfere if <42 days
What is the calving to first service interval?
65 days and interfere if >75 days
What is the calving to conception interval?
85 days and interfere if >95 days
What is the conception at first service target?
60% interfere at <55%
What is the conception in all services target?
55% interfere at <50%
What is the target for 120 day in calf rate?
64%
What is the target for 210 day not in calf rate?
<7%
How is longevity measured?
Average number of lactations the cow lives before leaving the herd
What does longevity indicate?
Significant welfare problem and is a key parameter to look at in any herd
Why do planned culls need to occur?
To remove older or less productive cows from the herd to allow other cows in with cows killed due to illness preventing planned culls
What should be done if there is a high cull rate?
Obtain a reason for culling data and get workers to rank out of 10 for the reason they were killed
How should culls be analysed?
Reason, age, lactation, days in milk
What should milk yield be compared to?
Expectation taking into account % fat and % protein
