What is a ‘late-born’ calf?
A ‘late-born’ calf is a calf that is born towards the end of a season or batch. They are anywhere up to 4 months younger that the first-born calves. In a spring calving season these calves are born anywhere from late March into May. Despite being late born, heifer replacement calves born at this time will still need to meet all the targets to calves down early in the spring in two years’ time. They are competing with calves born 2-4 months earlier than them. For calves that are for sale will also present challenges, they need to be well done to find good buyers for them at a late stage.
Are late-born calves less likely to flourish?
There is no doubt that late-born calves are up against it with disease challenge, thus lowering their chances of flourishing. There are so many cows and calves passing through pens during the season, increasing the disease levels. Even if a pen is emptied of bedding and freshened up, there is still a greater level of bugs than a shed that has been rested. Furthermore, there is a lower quantity of transition milk lying around. At the beginning of the season there are more cows calving and so there is a lot of transition milk available to feed calves. These calves get more of it by default and the benefits of it can easily be overlooked. Later calves often miss out of prolonged transition which can decrease the maturation of the gut and decrease their fight against diseases of the intestinal tract.
Is there any change based on whether they are a dairy or beef cow?
The principals are the same for both dairy and beef cows. Hygiene is still a key part of successful calf rearing. Vaccinations are viable in both cows, so it is advisable to speak to your vet on those options. One small difference with beef cows you don’t need to worry about transition milk feeding as that will naturally occur but being conscious of this is very important in dairy systems. Furthermore, beef cows tend to have better quality colostrum, so lower quantities may be sufficient. Hence, when feeding colostrum, it is better to manually feed dairy calves to ensure they consume adequate volumes.
How do I prevent illness in my later-born calves
In a spring calving system, once the peak is over you should take the chance to clean and disinfect sheds/pens as if it is the start the season and if possible, leave them rest for a couple of days between animals. This will greatly lower disease burden. It is also even more beneficial to remove calves from cows immediately post-calving to limit exposure to pathogens in the calving pen. If disease is a persistent problem in your late calves, it would be an option to do some tests to identify the bug causing the disease to make a specific plan. In some cases, such as Rotavirus vaccines are available. In other cases, such as Cryptosporidium calving outdoors may be a viable option to reduce the prevalence of the disease. Also, feed transition milk to calves for a minimum of five days but ideally for up to three weeks, if it is available.
What should I be most focused about in terms of managing my youngest calves?
The great challenges for late-born calves are disease burden, availability of transition milk, competition with older calves and labour to dedicate to rearing them. The key is to resist pushing calves, or ‘get them out the gap’ – these calves need all the TLC that older calves receive. Dedicate the time to them and the rest should follow. Ideally keep them on their own so they don’t have to compete with older, stronger calves. If they must be kept together, ensure there is plenty of trough space. When at grass there are options such as energy licks that can ensure all calves have a greater chance of consuming them, compared to eating concentrates.
Do you think there is any technology out there to help provide more insight on late-born calves and potential issues that might arise?
Late calves come at a time when focus begins to shift to other things such as grazing, breeding and silage. Keep rearing simple and stay focused. Simple strategies such as checking weights frequently can highlight performance issues before the trained eye might see them.