Building use and ventilation
You may be seeing problems in the dutch barn, but is this really where the problems are happening, asked Mr Williams.
“Calves may not be getting a good start and then the problem could be manifesting itself later. For example, lungs may have been weakened early on and then when they are exposed to other animals in the dutch barn, that’s when problems develop.”
The height of the building currently used to house baby calves was identified as one of the main areas for attention.
The small calves housed in this building are never going to create enough heat to drive air movement in here, said Mr Potter.
Consequently the Hit Squad advised changing the order in which calves move through the system so that building size reflected the size of stock housed.
“I would suggest moving the older, weaned calves into the building currently used for young baby calves. These older calves would be more able to drive ventilation,” Mr Potter said.
However, the central ridge would need to be opened to allow air to exit, and machinery relocated to provide more space. Space boarding with gaps of no more than an inch should also be installed.
The young calves could then be housed in the smaller, mono-pitch buildings, allowing the farm to manage the same group sizes as before. Calves could be kept here for the first six weeks on milk and then moved.
The Hit Squad stressed that drainage would need to be improved in these sheds to house younger stock and advised partitioning off the bedding area from the milk feeding area.
Mr Williams commented: “I would suggest splitting bulls and heifers out when they move from the mono-pitch shed. You can then use the best buildings for the future of the herd.”
Mr Willliams suggested putting bulls in the dutch barn and heifers in the high-roofed building next to the parlour. This would help deal with stock congestion – particularly considering the farm’s intention to grow the herd to 200 cows.
Mr Williams advised undertaking blood immunoglobulin testing to establish whether calves were receiving enough colostrum.
“My concern is not what you are giving them, but the fact you don’t know what the calves think of it,” he said.
“You are stuck with yields, so it’s the quantity that needs addressing. You may not be able to improve quality, but blood test results will tell you if you need to give more.”
Mr Potter said a colostrum meter could come into play as a means of quality control when freezing supplies. This would ensure only the best colostrum was frozen.
Regarding pneumonia control, Mr Williams stressed that colostrum management was the first port of call, rather than vaccination.
“Colostrum makes a bigger improvement on the scale than vaccination. You can manage the pneumonia challenge down by looking at building design and improve resistance through colostrum management.”
Owing to the fact that a number of people are working with the calves, it would be useful to write down some team protocols, said Mr Potter.
“I would suggest putting up a whiteboard or blackboard next to the calves so things can be ticked off when they’ve been done, rather than relying on texting people.”
1. Roof too high for baby calves to ventilate – move weaned calves into this building. 2. Open ridge to improve air outlet. 3. Install space boarding.
4. Dutch barn not ideal as shared air space with mixed ages. Split stock so older bull calves here and heifers prioritised elsewhere.
5.Blood test calves to see if colostrum feeding is adequate.
6. Move young calves into smaller, mono-pitch building. Improve drainage and partition off bedding and feeding area.
A building containing animals on a still day ventilates by a phenomenom known as the “stack effect”. The animals drive this with the heat they produce.
This hot air rises within the building and tries to escape through a high-level outlet. This creates a negative pressure within the building, sucking clean, dry, cooler air into the building through inlets. Outlets are above eaves height and inlets are below eaves height.
Think of the movement of air in a livestock building in a similar way to the movement of air/smoke in a fireplace. The animals have a similar role to that played by the fire – enough animals are needed to create enough heat to push air up and out of the building outlet (chimney).
Both inlets and outlets are needed to allow air to be pushed up and out of the building and new fresh air to be drawn in. It’s essential you have both. The most common finding in buildings is a lack of high-level outlet.