14/02/2024
Dairy farmers nationally are on the cusp of the busy spring-calving period. There is, however, an opportunity to make last-minute adjustments or tweaks to your calf housing to improve the health and welfare of your calves.
Speaking from a recent Teagasc / Animal Health Ireland (AHI) CalfCare event in Co. Cork, Charles Chavasse, Area Veterinary Manager of Zoetis, outlined the key steps to optimise calf housing on dairy farms, while highlighting immediate tasks that can be completed before calving commences.
A good quality calf house has five key requirements, these are:
Ventilation – well-ventilated with clean, fresh air that is well distributed;
Draught free – calves exposed to draughts will lose excessive body heat;
Warm – temperature is important for young calves, the optimal air temperature for calves under three weeks old is 15-20oC;
Dry – sufficient floor slope, no damp walls, no rain ingress or no leaking water troughs;
Clean and cleanable – easy access to clean without impacting other pens.
Ventilation and controlling draughts
Centring his presentation on tasks dairy farms can complete prior to the commencement of calving or activities that will improve the above during the calf rearing period, Charles first touched on the topic of ventilation and controlling draughts.
Where farmers are aware they had issues with ventilation in the calf shed last year and have yet to complete remedial action, he suggested the use of fans or an air tube to help remove stale air from the shed. When this option is selected, he urged farmers to ensure the device is adequately designed for the shed in which it is fitted to provide the best results and to ensure that air is flowing in the right places.
Alternatively, where a calf shed is fitted with sliding doors, Charles advised farmers to fit gates, sheeted with stock board, on the inside of these sliding doors. On days when the ventilation is poor within the shed, the sliding doors can be opened to increase the air inlet area. When this option is selected, draughts need to be minimised through the use or wind breakers above gate height and rubber below and around the hung gates to prevent air ingress at calf height.
“Having a supply of fresh, clean air coming into a shed is essential for rearing calves,” Charles told those in attendance at the Volac supported event. “It brushes out the moisture and it moves out bugs and noxious gases. Viruses are also deactivated much quicker in fresh air than stale air.
“Having clean air is really critical, but how it gets into the shed is also important because we can’t have draughts, so ideally a shed for calves should be sealed from four foot down,” Charles explained.
Warmth
Calves perform optimally in a temperature of 15-20oC - a challenge faced on Irish farms during the spring period. Adding to this challenge, Charles explained, is the lack of heat produced by calves until their rumen is developed.
Having an adequate bed of straw, to allow calves to ‘nest’ is one solution. However, with straw being scare on many farms this year, Charles explored the option of calf jackets.
“Personally, I am a big advocate of calf jackets. I came to calf jackets a number of years ago more so from the point of view that when you put a calf jacket on a sick calf, they recovered better and they would frequently catch up with the healthy calves not wearing calf jackets,” Charles said.
Citing research work, Charles said that calves fitted with calf jackets outperform those not when offered the same feed. And for farmers opting for this solution, the correct use of calf jackets is important.
“First of all, the calf has to be dry before the calf jacket goes on. The jacket needs to be made out a breathable material and it needs to have adjustable straps – with jackets with buckles preferred over Velcro,” Charles said.
When jackets are being reused, they need to be washed before transferring from one calf to the next and the optimum time to remove is at approximately four weeks of age. However, caution is advised when removing calf jackets, as to avoid removing them in periods of cold weather. In this instance, calf jackets should be left on until weather conditions improve.
Moisture and cleaning out
Before the calf shed comes into use, Charles also advised farmers to ensure that moisture sources – such as leaking water troughs – are fixed. Moisture present within the calf shed not only serves as a pathway for bug and pathogen survival, but it also lowers the temperature of the calf house.
One simple solution to reducing the amount of moisture present within the calf shed is by washing all feeding utensils and equipment externally of the calf shed. If this can’t be achieved, the resulting dirty water should place in a drain to exit the calf shed quickly, rather than simply pouring the waste water out in the feed passage of the shed to make its own way to the drainage system.
The topic of how frequently the calf shed should be cleaned out was also discussed, with the factors of drainage, floor slopes, ventilation and stocking density all being critical to how often the shed needs to be cleaned out.
Charles said: “How the shed is designed will impact on how often you have to muck out. In really good sheds, with a 1:20 floor slope, 2m2 per calf of floor space and good ventilation, you might get away with having to muck out every four to five weeks.
“Whatever system you are using, I would encourage you to do the kneel test. Enter the shed and walk straight to the back of the shed to where the calves are lying down. Kneel down and get your nose 6 inches off the ground, because that is what the calf breathes,” Charles said.
This test should be completed immediately upon arrival to the back of the shed, Charles explained, as the human nose becomes accustomed to the smell of ammonia rather quickly. The presence of ammonia – a pungent smelling gas – can have a negative impact of the calves’ respiratory system. The presence of this gas reduces the performance of the cilia – the hair-like projections in the lungs that clear the lungs of dust and bugs – thus heightening the risk of respiratory infections.
At which point to start mucking out, Charles said: “If your knees are dry and you can’t smell ammonia, repeat the test in two days’ time and when you can smell ammonia or when you kneel down and your knees are wet, you have to start mucking out.”
Where cleaning out is required, Charles has preference for removing the waste bedding and then applying lime to the shed’s floor before bedding. This approach, rather than washing the shed with high pressure hoses, serves to reduce the dispersal of pathogens in water droplets through the washing action and it also maintains shed temperature, as the floor doesn’t need to dry prior to restocking.
Calf Jackets available to order just ring 0539145755
