NOW that calving is underway or close to being completed, it is time to start preparing for weaning and the eventual sale of the calves and development of replacement females.
When cow calf pairs are out on pasture in the spring, there is a tendency to put off the steps needed not only to set the feedlot calf up for success, but also to lay the groundwork for incoming heifers.
Proper management and the use of vaccines will help make weaners more resilient to the disease challenges associated with the stress of weaning, commingling and transport.
Castration and dehorning should take place as soon as possible. Waiting too long to remove the testicles, either by banding or cutting, increases the risk of bleeding and infection, and knocks the calf off feed for an extended period of time.
Scooping needs to be done before the horns reach 50mm in length to avoid having an open sinus cavity in the head, which is prone to infection and fly-strike.
Regardless of the technique, pain control is highly recommended as it keeps the calf on feed during the healing process.
Regardless of the technique, pain control is highly recommended as it keeps the calf on feed during the healing process.
Vaccinations are also a critical, but are often misunderstood or under-utilised. When a calf is born it has no immune globulin proteins circulating in its blood stream to help fight infections.
All of their initial immune globulins come from the colostrum at the first feeding, which needs to take place ideally within the first six hours after birth. The ability of the calf to absorb immune globulins past 24 hours of age is almost zero.
These proteins are made by the female, and concentrated in colostrum prior to birth, this is why vaccination of pregnant cows is essential in providing immunity for the calf. Once the calf is up and nursing, those immune globulins provide immediate resistance to disease. However, these are mostly gone by around three to four months of age.
This is an important concept to understand for two reasons. Firstly, an injectable vaccine before this time frame means that any antigens for diseases you are vaccinating for (IBR, BRSV, PI3, etc) will be neutralised by the immune globulins delivered in the colostrum.
Essentially, if you have vaccinated the pregnant cow for those same diseases, and the calf nursed properly, there is no need to deliver those same vaccines to the calf prior to four months of age.
Secondly, the calf's immune system is not ready to see and react to the vaccine. It takes time for the white blood cells responsible for the development of a systemic immune response to learn their jobs and be able to react to invading bugs.
One important exception to the use of vaccines in young calves is the use of intra-nasal vaccines. These vaccines are not interfered with by colostral immunity.
Timing is also critical. Most vaccines are labelled with directions to wait at least one month wait before administering a booster shot. Given too early, there will not be the second strong immune response to provide superior protection.
- Toby Doak is a livestock nutrition advisor with Alltech Lienert Australia.
