Take steps to protect sucklers from scours
One of the biggest risks to suckler calves occurs around calving as most beef calves are sired by well-muscled high growth rate bulls. Once a suckler calf is safely delivered, its survival chances greatly increase.
The next major threat to health comes from infectious scours and, to a lesser extent, pneumonia. The majority of calf scours are caused by six organisms: viruses such as rotovirus and coronavirus, bacteria such as E coli and salmonella, and protozoa, cryptosporidia and coccidia.
Reports from the veterinary laboratories indicate that cryptosporidium and rotovirus are the most frequently found organisms associated with calf scours.
While there are vaccines available to control rotovirus, no vaccine is available to combat cryptosporidium. All the same, if there is good control of viral and bacterial infections, through the use of good hygiene, management and vaccines, the effects of cryptosporidium infection will be less severe.
Cryptosporidium is a protozoan parasite similar to coccidium that is extremely common in the environment. It can affect a wide range of species but only causes problems in newborn animals, apart from humans, where it can cause serious diarrhoea in adults as well as infants, as the population of Galway will remember from a few years ago.
Outside the host animal, the parasite exists as a resistant spore called an oocyst which develops in the intestine. Sources of infection for the young calf are from the cow and the calving shed. Estimates from the US suggest that an adult bovine sheds 2.5 million oocysts per day in the faeces and that a scouring calf could shed up to 50 billion oocysts in a week.
Since there is no vaccine to control crypotosporidia and only a moderate response to medication, prevention assumes major importance on farms where the diseases have been a problem. A healthy calf with rapid development of immunity from maternal colostrum is a good start.