Getting back into the swing of things after Christmas and New Year often takes a degree of motivation. However, there is nothing more motivating than a freshly born calf -- and for the spring-calving herds, this will soon be a reality.
By now, calving and calf-rearing facilities would have been cleaned, disinfected, repaired or constructed and awaiting new arrivals. Dry cows have been run through the crush on a number of occasions with vaccinations for IBR, salmonella and rotavirus/coronavirus commonplace. Final doses for adult fluke are also administered where necessary.
When we consider the prevention of diarrhoea and scouring in calves, good hygiene and vaccination where appropriate are invaluable methods to manage disease.
The new recommendations by Animal Health Ireland (AHI) to remove the calf from the cow immediately after birth to a clean individual calf pen or hutch to minimise the chance of infection may be an effective change for some.
However, one can't forget the value of colostrum and it's a good time to remind ourselves why it's so important to calf health.
When it comes to colostrum, two key factors need to be remembered:
1. Ruminants (calves, lambs and kids) are born without any antibodies, and rely on good quality colostrum for their early immunity against disease.
2. Calves have a brief but critical window to receive colostrum to give effective disease prevention.
Factors that result in good quality colostrum include:
-Maximising the intake from a cow's first milking after calving. Research in Australia showed the first milking after calving to contain 21pc total solids, which is more than double that in normal milk, and 11pc protein of which nearly half is antibodies. By day two, antibody concentrations are negligible and by day three total solids had decreased to 13pc.
-Older cows produce better colostrum than heifers as it contains more antibodies. Colostrum will be of poorer quality from cows that are in poor body condition or cows that have been induced.
-Vaccinations against specific diseases boost the amount of antibodies produced against the virus or disease in the colostrum.
-The use of dry cow therapy does not affect colostrum quality provided the withholding period has been met.
-Mastitis colostrum and cows being treated with antibiotics (whilst being withheld) should not be fed to calves.
-Newborn calves have microscropic holes in the gut wall which allow large antibodies to cross from the gut to the bloodstream. However, the calf's ability to absorb these antibodies decreases rapidly and is only half as efficient after six hours.
At 12 hours of age, 90pc of these pores have closed and by then the calf's stomach is secreting acids and digestive enzymes which denature these antibodies and also limits their absorption. So to maximise this passive immunity, Holstein calves must receive three litres within four hours and four litres within 12 hours.
-Leaving newborn calves on the cow is not an insurance against problems, as 40pc of calves won't get enough colostrum, combined with an increase in the risk of infection. So, as recommended, milking three litres into a bucket and either feeding it directly or via a stomach tube within four hours can be a way to ensure a calf gets enough.
-Where calves miss out on enough colostrum, they must activate their own immune system early. As this takes three to four weeks to become fully functional, the calves are more likely to be unthrifty, more prone to infection when disease outbreaks occur and more likely to develop secondary problems, such as pneumonia.
Getting calves off to a good start with adequate colostrum is the first step in ensuring a well-grown heifer enters the herd in two years time.
Dr Mary Kinston is a farm consultant based in Kerry. Email: firstname.lastname@example.org