What does Evidence Based Management mean?

For those of you that have read my website you may have seen the phrase “Evidence Based Management” and wondered what does this mean? To me “Evidence Based Management” is about learning and incorporating the latest scientific evidence in a way that will benefit your specific farm.  Two examples of this can be found for one of the first steps in calf management:  Colostrum management!

Example 1: There is an abundance of evidence gathered through multiple studies that calves with failure of passive transfer are at a greater risk of disease (mortality) and death (morbidity).  While your farm may have low number of calves impacted by calf-hood disease (called prevalence or incidence in academic literature), ensuring that you provide high quality, clean colostrum in a timely manner and achieving successful passive transfer (they get enough colostrum) will help reduce the risk of outbreaks and keep your calves healthy and growing. 

While you could say, 'my calves are healthy therefor my colostrum management is good' or 'I have problems and that means colostrum is the problems', a better approach is to gather data.  Collecting blood samples from your calves when they are between 1 and 5 days of age and evaluating the serum using a Brix Refractometer (or comparable tool by your veterinarian) can tell you for sure if at least 80% of your calves have successful passive transfer.  If this is the case, you are passing the threshold that has been shown to give your animals the best chance for success.  You can then just keep your colostrum feeding program the same and monitor your calves to make sure nothing changes, or if you do not meet this threshold begin to make changes and have a clear outcome for success. 

Farm meeting, such as this one of the Lambton County Holstein Breeders Club, is a great way to get together and learn about the latest advances in dairy management!

Example 2:  The other factor of colostrum management that is both easy and important to evaluate is the cleanliness of the colostrum fed to the calves.  While you may achieve successful passive transfer, if you feed dirty colostrum with lots of bugs, your calves will still get sick.  For this reason, taking a sample of colostrum from whatever device you feed calves from (i.e. tube or nipple of bottle) will tell you if the colostrum is staying clean after it is collected from the cow and is okay to feed to your calves.   Immediately freezing the sample and having your veterinarian submit it for total plate count (here in Ontario it is usually the University of Guelph’s Animal Health Lab) will tell you how much bacteria is in the sample.  If the sample is contaminated, you can then evaluate the steps of your cleaning program by taking samples from the tank you collect the colostrum from, after it has been thawed or heated to feed the calf, after pasteurization (if you pasteurize colostrum, and the feeding device (tube or nipple).  This way you can find out where contamination is occurring on your farm and correct it.  Re-sampling can then tell you if you succeeded and monitor to make sure there is not a breakdown in cleaning protocols or equipment.

The above is an interpretation of total plate counts for milk, colostrum, or milk replacer.  All of which, if contaminated by bacteria, can make your calves sick.  Samples are an easy way to ensure you are feeding your calves the best!

There are lots of examples and methods to evaluate your on-farm management for economic, welfare-friendly practices that can be integrated into your farm.  Stay tuned and follow my blog for more information!

Can a calf’s breathing tell me about how it is feeling?

 Yes!

Your calf is breathing faster than normal (over 50-75 breaths per minute), what does that mean?

The calf was just running and playing

               Needless to say this is a good sign.  Calves with good welfare play more and are more likely to be healthy.  However, calves that stop playing quickly or don’t play when all the others in the group are playing may be sick or stressed.  Calves that do not play for long or cough during exercise could have, or be recovering from, respiratory disease (pneumonia).  Keep an eye out for these girls.

It is hot out

               Calves (and cows) do not sweat, so when it gets hot they will increase their breathing to cool off.  Typically, calves will begin to show signs of heat stress when temperatures get above 30C (90F), with humidity causing them to be more sensitive to heat.  They are even more vulnerable to heat stress if it does not cool down at night.  Well in this case, faster breathing does not mean the calves are sick, they will need lots of water and the environment will need to be evaluated to see if they can be cooled off.  Examples include using fans, tipping huts up to increase air flow and providing extra shade.  Since calves are not great at controlling their body temperature, they are at risk of heat stress so keep a close eye on them.

Calf is sleeping, it is not too hot out…

Shhh.... Don't wake the baby!

If they are sound asleep they may be dreaming and twitching in their sleep.  If you can see their eye and it is twitching it may indicate they are in Rapid Eye Movement (REM) stage of sleep.  If you are unsure, you can wake them up.  If their breathing slows down, let them go back to sleep as growing babies need their sleep!

Calf is not sleeping or playing, and it is not hot out

A calf that does not look at you when you approach, or stands with head down, may not be feeling well. 

This could indicate an issue.  Calves breathing may be elevated due to pain, illness, or compromised lungs.  Calves with active diarrhea, umbilical infection, or respiratory disease may show signs of fast breathing.  Look for these signs and take their rectal temperature, a temperature over 39.9C (103.9 F) is considered a fever and a complete health exam is needed to try and determine the root cause. 

If a calf does not have a fever, but has diarrhea, they may be in pain.   Studies have shown that providing calves with metacam (Meloxicam) when they have diarrhea allows the calf to rest easier and recover faster.  Just make sure you provide the calf with electrolytes and lots of water so it stays hydrated.

An arched back or raised tail could indicate pain or illness in a calf.  Look for a fever, diarrhea, umbilical infection, or respiratory disease (pneumonia) in calves that stand this way

                 No diarrhea, no fever…

A calf may also breath faster due to prior inflammation and damage to the lungs resulting from pneumonia (bovine respiratory disease).   Respiratory disease can have long term impacts on a calf’s health including slowed growth for 6 months after illness, increased risk of death, and even difficulty calving as an adult.  If respiratory disease is a problem in your herd prevention is key. However, for those already affected, providing a low stress environment for calves well they recover is important.  These calves will be more vulnerable to heat stress, and handling stress for several months after initial illness.  Keeping stocking density low and grouping calves by disease history can help you manage these vulnerable animals.

Look for a calf lying with her neck extended, this may indicate discomfort, or challenges breathing

Whether it is due to the environment, health, or just a dream - breathing rate can tell you a lot! Making this observation just one more tool in your calf management tool box.

Keeping Calves Healthy this Winter & Spring

Brr it is cold out there… okay now it’s hot! I mean cold… so this winter has been unpredictable here in Ontario.  The question of should I wear a jacket to work seems to change day to day.  While I am loving not shoveling a whole bunch of snow, it has had some challenges for calves. 

Changes in weather can be hard on calves but if we keep in mind their comfort we can keep them healthy and growing.  One of the first things to keep in mind is something called the thermoneutral zone which is the range of temperatures that calves are able to stay comfortable without spending energy.  In human terms it is the temperature range where you are not sweating or shivering!   Calves are small and lack the body fat and giant energy producing rumen that adult cows have, so they are more comfortable at higher temperatures. 

THE 'JUST RIGHT' ZONE aka Thermoneutral zone

A newborn calf that is healthy and dry does not spend energy between 10C (50 F) and 25C (78F), while a one-month old calf does not spend energy between 0 C (32F) and 25C (78F).  If a calf is sick or wet, they are more sensitive to low temperatures and will become cold at much higher temperatures.  Think of huddling under the covers the last time you were sick, or think fondly of getting out of the pool on a warm summer day and wrapping yourself in a towel to stay warm.  The same principle applies to calves.  A warm and dry calf is a calf that will stay healthy.    Does this mean on cold days calves are doomed?  Nope, we just have to make sure we give them the tools to keep warm!

Save energy - Keep them warm

First step? Keep them dry.  This could be by using heat lamps for newborn, the dam can lick the calf dry, there are commercial calf warmers, heat lamps, and deep bedding with straw.  Straw works well because calves can nest into it and it keeps heat in.  Well products like shavings are great for keeping calves dry, since they cannot nest into it.  This means that they will have to spend more energy keeping warm as calves can’t cover up and will have more of their body exposed to the cold.  Straw is basically the calf equivalent of a good winter jacket.  Since straw is expensive and can be hard to maintain I recommend a combination of shavings, straw and a jacket in the winter.  A good shavings base to absorb liquid, straw on top for calves to nestle into with the goal of having the back legs at least partly covered when they lay down, and a calf jacket to keep them warm.  

Then maintain! Make sure the lying area stays dry.  Calves lay down for around 20 hours a day!  So there bedding needs to be dry and warm.  This winter, and most springs, hutches are really hard to manage and lots of bedding will be needed as the wet conditions will mean that the inside of hutches are really likely to be wet and muddy- which will mean sick calves!  And remember, sick calves are more sensitive to cold temperatures and more likely to be chilled.

Careful of wet bedding in hutches when the weather is near freezing and ground is wet and cold

Stoke the fire – Keep them fed

The next big challenge – keep them well fed.  If calves do not get enough food they can run out of energy and will have trouble staying warm and keeping their immune system up and running.  Rule of thumb?  Feed Holstein calves 4L of good quality colostrum (stay tuned for more on what good quality is!) within 4 hours to get calves off to a good start.  Then feed calves at 20% of body weight (over 8 liters of milk per day).  Keep in mind that for a calf to maintain health and growth they will typically need to be eating at least 1 kg of calf starter a day and calves will NOT be able to do this for at least the first month of age.   

If you keep calves warm, dry, and well-fed, you are well on your way to raising healthy and happy calves – which will make you, and your pocket book healthy and happy!