There is more to ensuring a trouble-free calf rearing season than just spreading out the bedding and hanging the gates. Truly successful, robust calf rearing operations require careful planning, thoughtful execution and a high level of attention to detail.
Recent research has highlighted the importance of achieving high pre-weaning growth rates in dairy calves. Calves which fail to grow fast in the first eight weeks of life will never reach their future potential, either in further growth to mature size or in milk production. Research has shown that heifers which calve down at less than 90% of their predicted mature bodyweight will produce less milk and have higher empty rates as rising three-year-olds. We now know this production effect continues well past the first lactation.
Successful operations have a robust plan in place that will still produce the desired results regardless of weather, milk price, disease outbreak or an injured staff member. Forewarned is forearmed so think carefully about where the weaknesses and risks in your system are and potential solutions to common problems so you can react quickly in the hour of need. Stress levels are always decreased when ‘Plan B’ is already in the back of your mind.
So what can be done to ensure calves get off to a great start and achieve high weight gains? Here are a few tips to ensure success.
Key focus areas
When thinking through your plan for the coming season, there are a few key areas to focus on. Getting them right underpins success for the whole operation.
Colostrum intake for new-born calves.It is vitally important that every calf which enters the rearing shed gets sufficient high-quality colostrum either direct from suckling its dam, or supervised feeding of collected first-milking colostrum. When thinking about colostrum intake for calves, there needs to be sufficient quantity, of sufficient quality, and quickly enough for the antibodies to be absorbed.
There is no transfer of immunity to the calf while still in the uterus, so the calf must ingest antibodies from colostrum to provide some protection over the next 3-4 weeks, until its fledgling immune system begins to produce its own antibodies. The intestines of a calf are specially adapted to absorb these antibody molecules, but this ability diminishes quickly after birth, being almost halved within 12 hours of birth and almost gone by 24 hours.
New Zealand studies have shown that about half of calves left on their mothers will not ingest enough colostrum to be protected and almost all those that do, will do so within six hours of birth. There is little to be gained by leaving calves out in the paddock longer than six hours, so collecting calves from the springer paddocks more than once every 24 hours gives the calf rearer a better opportunity to ensure adequate colostrum intake. Calves can then be fed collected first milking colostrum via a teat or stomach tube to ensure adequate intake.
While overfeeding can be an issue in the following weeks of rearing, it is certainly not a concern in the first 24 hours of life, so ensure calves receive enough colostrum. Aim for 12% of bodyweight in the first 12 hours of life, and a total of 15% bodyweight fed over the first 24 hours, so for a 35kg calf, that means 4.2 litres by 12 hours and at least 5 litres by 24 hours.
Often farmers make a visual assessment of whether a calf has fed from the dam, but this is fraught with inaccuracy. New-born calves can suck a lot of air during their first feed, making them look much fuller than they actually are. If in doubt, top them up from a teat or stomach tube.
Make the best of the facilities you have. We would all love the perfect calf shed, but good calves can still be produced in an older style barn or shed. Calves need good drainage below and good ventilation above. In an old shed, ventilation can be improved by cutting a gap at the top of the back wall and the layout can be improved by hanging gates or splitting pens up with light, removable fences. Think laterally about simple, cost effective changes you could make to improve the layout, drainage or ventilation in the shed.
Avoid overcrowding. One of the most common disease outbreak situations seen by vets happens in the fourth to sixth week of calf rearing, when calves have been kept in longer than expected because of bad weather. The environment is already becoming quite contaminated by then, so overcrowding the calves can tip the balance and result in an outbreak of scours. When planning numbers of calves per pen, allow a minimum of 1.5 square metres per calf but build some fat into the system by allowing extra room or a spare pen. If you’re short on space and calves need to be moved outside during poor weather, sacrifice a few straw bales to make a shelter. A Y formation of bales gives great protection from all angles.
Treat colostrum like gold. Correctly stored colostrum can be kept for several weeks, with very little loss of antibodies or nutrients, so look after it carefully. When fed to calves older than 24 hours, it provides a rich source of nutrients, the best probiotic around and tons of active antibodies which still act locally in the gut. Colostrum needs to be collected without any contamination from faeces, antibiotics or bedding materials and needs to be stirred daily to prevent a thick crust forming. Adding organic acids or natural yoghurt will help to preserve the colostrum by making it slightly acidic. This naturally ferments the colostrum, encourages the growth of good bacteria and prevents harmful bacteria from multiplying.
The human factor. For calves to be well looked after, they need a capable caring human in charge, so look after yourself. Manage frustration and exhaustion in yourself and your staff in spring so the health and welfare of the calves is not compromised. Have clear, written procedures and plans in place. Encourage a high level of attention to detail in the calf staff. More is missed by not looking than by not knowing, so train your staff to look closely at each calf, each feed.
Manage the paddock-to-pen journey.If a calf’s first trailer ride is not well-managed, it could well be its last. Soft bedding and having fewer than 10 calves a pen in the trailer are critical for ensuring that fresh, exposed umbilical cords don’t get damaged and infected. If calves are left waiting in a trailer for a long time, they can take in a lot of bugs before they take in any colostrum. Try to get them out of the trailer as soon as possible or tube them while still in the trailer if there is going to be a delay unloading them. Trailers should be covered wherever possible or backed into a shed if waiting as wind chill and rain can cool the core temperature of a calf very quickly without the cow there to shelter it.
Good system for identifying and recording poor performers. Find an effective removable method for identifying sick or underperforming calves. Colour-coded Velcro neckbands work well but numbered ear tags attached to elastic cord are a cheap, effective option. Make up a flow chart for deciding how to treat sick calves and record their numbers because there are often flow-on effects in later life.
Every calf rearing operation is different so record what changes you make to your system so you can track what works for you. In most farm situations, the calf staff are part of a bigger team and often compromises are made just to get everything done in the day. Acknowledge when you have cut a corner, so you can get back on track quickly if things start to go wrong. Think about where your system is vulnerable. Are you a one-man-band, lifting buckets of milk with a dodgy shoulder? Who will know what to do if you can’t?
When formulating a robust plan, start with the non-negotiable must-haves like adequate colostrum intakes and a dry, draught-free environment. Make the most high-impact changes your top priority. Enlist extra help from a keen local vet, your DairyNZ consulting officer or a local farmer with lots of experience. Pull together a calf-rearing group in your local area and critique each other’s systems. There is a wealth of information out there, and often the simplest solutions to problems are right under your nose.
For more information, contact your local veterinary clinic, go to www.dairynz.co.nz or www.healthycalves.co.nz
