I am so hungry.. or not


A bright, healthy calf looking to explore

Healthy calves have slick hair coats, respond quickly, are bright and will have consistent drinking and eating speed.  Sick calves will isolate themselves, decrease food intake and drinking speed, stop grooming, and be slow to explore. 

Maybe I am inspired since it is almost lunch time but I thought a talk about how much milk a calf drinks and how fast can tell you about their health.  Short answer, although not completely straight forward, if a calf drinks slower or less than normal then they are likely ill or becoming ill and should be assessed.  Which they do will depend on how sick they are and how much milk they are being fed. 

High Milk levels – over 20% of body weight to all you can eat buffet!

Calves at high milk levels will drink less AND slower when they start to get sick.  Pay attention to calves that are drinking less milk and seem to be ‘playing’ with their meal rather than drinking.  These calves are not being stupid, silly, or lazy – they are babies that probably do not feel well! For those of you with automatic feeders – extra bonus for you as the machine can be set to show you these calves!  Check alarms for slow or decreased drinking!

Low milk levels

Several studies have shown that calves fed 4 L (or 4 quarts for the Americans) a day are less likely to decrease the amount they drink when sick and more likely to just drink slower, which is harder to detect.  One way is to compare to the other calves close in age, the ones that take longer to finish should be examined for illness.  (Remember the top 3 causes in calves- Diarrhea, navel infection, respiratory disease).  If they are not drinking all their milk they are likely feeling VERY sick.  

Ever wonder why they do this?  Well like all mammals and even reptiles and birds, calves react to infection with behaviour changes we call Sickness Behaviour.



Sickness behavior

Regardless of species when we get sick, we act basically the same – although the “man cold” shows some can be more dramatic about it.  We have a fever, we do not want to socialize, we sleep a lot, eat less, stop grooming.   In people, think of someone with a flu, they curl up in bed, don’t want to do anything, and will turn down invitations to do anything.  In calves, they will also try and isolate themselves, eat less, drink less, sleep lots, and perform less grooming. This will show up as calves that have a rough hair coat, drink slower or less, and if group housed will be away from others.  Individual calves will show greater reluctance to stand and less interest in exploring new things.   While you (and calves) may feel awful when sick, all these behaviors help you recover faster.  However, in and emergency you may not perform these behaviors.  For example, if your house is on fire then you will get out of the bed even if you have the flu.  Think of calves in group housing, you may see a calf that you think is maybe sick but when you try and catch her all of a sudden she is running around and looking better.  This may be a response to fear which masks the lethargy associated with illness.

Milk- Short term survival versus long-term survival

 If a calf eats less, or not at all, when sick they are also starving the bugs making them sick.  If they have enough body fat they can survive a day or two with decreased energy intake and bounce back quickly.  However, if they are fed a restricted diet (fed at 10% body weight) then they may not have the fat reserves to keep functioning during this time and could starve before getting better.  For this reason,  even when ill calves that are on restricted milk intake may have a greater motivation to drink even when sick which may make them harder to detect.  Also, those fed at lower levels take longer to recover and shed bugs longer than those fed at a higher energy level.  

Take homes

When sick calves will either drink less, drink more slowly or both – depending on how much they are fed

Calves also isolate themselves, play less, rest more, and groom less when ill

Calves fed at low levels will show less signs of illness and take longer to recover compared to those fed at higher level.