Mooving in: Foundations of calf housing

The housing of calves can be done in different ways and choosing the best system is not always easy as it has to fit the farm. A good calf housing system should take into account the health and development of the calves, especially for the first weeks of life. The basic principle for calf housing is separating the calves from each other—and from older animals—to prevent pulmonary health issues. Therefore, it is advised to keep young stock in a well-ventilated area and separated from older animals for the first 6 months of life.

Calves are born without an active immune system and rely on passive immunity from colostrum for the first weeks of life. As calves get older, the passive immunity from colostrum will fade and the active immune system will take over. In early life, most diseases young calves experience are based on enteric pathogens transferred by animal-to-animal contact or the fecal-oral route, as well as infection via airborne pathogens. This means properly designed calf housing must provide optimal ventilation and ensure separation between the young calves and the older animals on the farm.

Calf housing should also be comfortable for the calves. Bedding plays a crucial role in both keeping calves comfortable and clean. Comfortable calves will use the nutrients they receive for growth and have limited energy losses due to responding to challenges from their environment. However, one of the main challenges concerning bedding is keeping calves clean and dry. Keeping them dry is especially crucial as calves in dry bedding will be cleaner and aid in maintaining their body temperature.

Of course, when investing in calf housing, there is always an economic factor as well as labor efficiency to consider. So, with separation, ventilation, bedding, price, and labor to consider, what options do dairy farmers have to raise healthy and productive calves?

Considering separation and ventilation, calf hutches are a very popular housing system for calves worldwide. Their popularity is connected to their ability to separate calves from each other while also providing a fresh-air environment. When placed on well-drained/sloped ground and well-bedded with the opening facing away from prevailing winds, hutches will give calves a dry and comfortable environment. An attention point to consider with hutches is the feeding placement, as the feed supplied—and the person feeding the calves—is exposed to the elements. There is special feeding equipment available to keep feed dry in an outdoor environment (Figure 1). Another option is to build a roof that will cover the area where the hutches are placed (Figure 2). This roof will also help calves handle the heat of summer.

In the case of individual pens, the placement and size of the pens is important. If the individual pens are placed outside, providing a roof or placing the pens inside of an open front barn will supply similar protection and benefits as calve hutches (Figure 3). If pens are placed inside, it is crucial to supply proper ventilation to achieve a comfortable housing system for the young calves. Most buildings have some natural ventilation, however, drafts and cold air dropping on the calves has to be prevented to minimize health issues.

In a closed barn, achieving proper natural ventilation without drafts is almost impossible because of the limited heat production of calves. In the case of natural ventilation, the production of heat is necessary to support airflow through the barn. Therefore, mechanical ventilation is the best option to let fresh air in on the ground level at the ends of the feeding alley and then to remove the air from the barn by ventilators in the roof.

Grouping calves is found to have a positive effect on feed intake and development but it does bring an added risk of animal-to-animal disease transfer, therefore the timing of group housing is crucial for calf health. If calves are healthy and achieved a proper amount of passive immunity via colostrum, then they can be grouped at 2 weeks of age. In situations where calves are individually fed, to minimize the risk of any disease transmission between the animals, the preferred age of grouping is 6–8 weeks. If the farm is experiencing an elevated level of disease pressure, it is recommended to keep the calves in separate housing until after weaning.

For group housing, there are typically two choices, group hutches or indoor group pens. Here, the same ventilation rules as discussed for individual housing apply. An additional point to consider for indoor groups of young calves (2–8 weeks old) is to create a bedded area in the back of the pen (Figure 4). By providing a kind of nest with closed side walls and a roof, unwanted airflow or drafts will be prevented.

Until the moment calves have a fully functional active immune system (10–12 weeks of age) there is a high risk of disease. Disease pressure is the function of pathogens and environmental exposure by immunity strength. For calves, we can influence one side of this equation in the early stages of life by perfecting colostrum feeding and the other side by optimizing housing management and biosecurity routines.

Cleaning is part of perfect management and individual hutches should be thoroughly cleaned after every calf. Group pens should be mucked out on a regular basis to keep the bedding dry and clean. For individual hutches or pens, it is recommended to work with an overcapacity concept so there is space for hutches and pens to be properly cleaned and even left unused for a period of time to reduce infection pressure.

In group housing, having enough space for each calf is the best way to reduce the risk of disease and support the development and comfort of the calves. It is advised to provide 2.5–3 m2 per calf in group housing. In the case of two-floor housing, with a slatted or scraped floor behind the feeding fence and a separate resting area, the space per calf can be reduced because a large portion of the manure will stay away from the bedded area.

Making deliberate choices about the type of calf housing will have a significant impact on the health, growth and development, as well as the future performance of young calves. When a calf housing system is well-designed, it can effectively mitigate health issues and allow young calves to utilize their full potential for growth and development, ultimately supporting the quality of future dairy cows.