The Milk Producer - January 2012 - (Page 38)

REARINGREPLACEMENTS By Amy Stanton Disease detection H ave a fever? Tired? Just want to sleep? Don’t want to eat or drink? When you are suffering from an infection, these behaviours conserve energy as your body mounts an immune response needed to help you get better. Like human beings, many other species exhibit these behaviours in response to infection—including dairy calves. These co-ordinated responses, called sickness behaviours, include fatigue, lethargy, and decreased appetite, thirst and grooming. By learning which behaviours to look for in your calves, you can detect disease early, greatly increasing treatment success. Bear in mind sickness behaviour is optional. The reason for being active just has to be more important than the need to rest. When you have a severe case of the flu, for example, you may not want to get out of bed to go to dinner with friends. If your house caught fire, however, you would not hesitate to get out. This is an important distinction when you observe behavioural responses to detect disease in calves. If they feel threatened, they will stop displaying sickness behaviour to flee. During this alarm phase, their behavioural response to illness will be much more difficult to detect. It is important cattle are calm when you are observing them for disease detection. If they are ill, they are more likely to display sickness behaviours. This will improve your ability to identify sick animals and treat them early. To observe how calves display sickness behaviour, we recently conducted a study at a heifer-raising facility in upstate New York. We wanted to determine behaviours that can iden- 38 | January 2012 | MilkPRODUCER Young calves can actually tell you how they’re feeling if you look for the right signs Calves needing only mild encouragement to stand are least likely to be sick. tify sick or poor growing calves. We observed individually housed calves three times over eight weeks to identify behaviours during clinical illness and behaviours characteristic of poor growing calves generally. Our study identified several behaviours, including smaller comfort zones, known as flight zones, willingness to approach a stationary observer and changes in standing postures. The first behaviour we associated with clinical disease and poor growth is a small flight zone, or the need for more encouragement to rise. Calves that stood with mild encouragement—either as soon as an observer approached or after the observer said ‘up’—were the least likely to be sick and had higher body weight gains during the milk-fed period. Calves with a small flight zone did not stand until the observer entered the pen, and were the most likely to be ill and have lower bodyweight gain. This is consistent with sickness behaviour. Sick animals are more lethargic and less interested in their environment. Healthy calves are more likely

Table of Contents for the Digital Edition of The Milk Producer - January 2012

The Milk Producer - January 2012
Contents
Editor’s Notes
DFO Chair’s Message
Dairy Update
DFC Promotion
Farm Finance
Research
Applied Science
Ruminations
Rearing Replacements
Markets
New’N’Noted
Back Forty

The Milk Producer - January 2012