- Pre-weaning average daily gain greatly affects lifetime heifer performance.
- Colostrum management is the most important factor for calf health and lifetime performance.
- Feed calves enough calories to increase average daily gain and develop fat stores for proper immune system function.
To care for calves well, caregivers must do the same things every day at the same time and revel in the monotony of being exact. When things are going well, it should be somewhat boring.
Overall, it helps to know why. Why feed calves well and deal with the frustrations that come with the job? Why does it matter if it is done well?
The first answer is straightforward; when calves are cared for well, you’ll have fewer sick or dead calves. Sick calves and dead calves are a considerable time, resource and emotional drain. Limiting sickness and mortality is better for the dairy and the caregiver, but there are bigger benefits as well.
Long term effects of calf illness
While calf morbidity (illness) and mortality (death) have significant immediate impacts, studies show that there are also long term effects.
- Several studies show calves treated for pneumonia or scours are more likely to be culled or leave the herd early.
- Similar studies showed calves treated for scours are almost three times more likely to calve after 30 months of age.
- Another study showed heifers that were never treated for respiratory disease were twice as likely to have a calf as treated heifers.
These are all important markers of lifetime performance and the success of a dairy operation.
Pre-weaning calf average daily gain affects lifetime performance
But what if morbidity and mortality are under control? What is the motivation to keep up the excellent work besides keeping morbidity and mortality low?
Several studies have reported that pre-weaning average daily gain (ADG) has significant impact on later performance.
- A Cornell study from 2012 showed that for every additional pound of ADG, an additional 1100 lbs. of milk was expected in first lactation, and an extra 2280 lbs. of milk was expected in the first three lactations. This effect was linear, meaning the more ADG in the pre-weaning period, the more productive the animal.
- A study in 2016 showed an additional 1430 lbs. of milk in first lactation for every additional pound of ADG pre-weaning. Interestingly, the 2016 study also indicated the effect was true for the total production of fat and protein as well.
- A University of Minnesota study from 2016 reported similar results with weaning weight and pre-weaning ADG, both significantly correlated to 305-day milk, fat and protein.
How to maximize pre-weaning calf average daily gain
So now, the question is what needs to change? In general, limit calf stress as much as possible and promote growth. Anything that takes away energy from growth needs to go, and there is justification to add things that improve growth.
The absolute most impactful thing in a calves life that predicts ADG, health and lifetime performance is colostrum management. Feeding the correct amount of quality, clean colostrum in the most important thing you can do for a calf.
- Colostrum: 1 gallon of quality, clean colostrum fed within the first 4 hours of life with 2 quarts of colostrum fed at the second feeding.
- Quality colostrum correlates to a refractometer reading of 22-23% Brix.
The second thing to note, calories fed above maintenance correlates to ADG and calf health. This means feeding calves the correct amount to encourage growth and maintain fat stores needed for the immune system.
Emphasis on special care in the winter is necessary as the cold temperatures cause maintenance requirements to rise.
- Milk: Push calves hard, the research is there to show the benefit. Offer 1 gallon twice per day or 3 quarts 3 times per day starting on day 2 of life.
The lifetime performance increase from pre-weaning average daily gain is linear, so the higher pre-weaning ADG is, the higher the benefits for lifetime performance.
The first step is to measure this value for individual calves and then define a goal.
- ADG: Doubling birth weight by weaning is a reasonable goal and provides an ADG that improves first lactation and lifetime performance. Usually, this is around 1.5 lbs./day.
Focus on the future
The reason we should care about pre-weaning calf performance is that this period significantly affects the lifetime performance of the calf and the dairy as a whole. What a calf experiences in the first 60 days of life matters for the lifetime production of that calf.
So when you are questioning why you are dealing with calf chores, remind yourself that how well you care for those calves is setting up the success of your dairy in the future.
Reviewed in 2020