University Park, Penn. - There's a lot of good things going on under the roof of a smart heifer housing barn.
It promotes the well-being of animals at their various ages and provides their caretakers with safe and efficient working conditions, agricultural engineer Dan McFarland observed during a two-part "Housing Heifers From Weaning to Pre-Calving" webinar hosted by Penn State Extension Dairy Team.
The barn also protects the environment and is cost-effective to build and maintain.
The goal of any heifer raising facility should be to raise healthy, well grown dairy replacements that are ready to enter the milking herd between 22 and 24 months of age, McFarland said. That means heifers that are ready to breed at 12 to 15 months of age.
Besides good nutrition, proper health care and exceptional husbandry, a good heifer raising program must have a first-rate environment.
Heifers can thrive in facilities that provide plenty of clean, fresh air and control drafts, offer clean, dry and comfortable resting areas, and convenient access to feed and water. They must have confident footing and be protected from weather extremes.
For caregivers, the facility needs to offer good observation and access to each animal, easy feeding and care, and simple animal handling, isolation and restraint. There should be proper lighting, safe working conditions, and convenient cleaning and manure removal.
Housing by age
The methods used to house heifers run the gamut from simple, reconfigured older barns to elaborate freestall buildings and from naturally ventilated pack facilities to self-cleaning barns.
Regardless of the method, McFarland underlined a heifer housing facility must provide the management and environment that allows consistent production of healthy, productive animals throughout the entire year.
Transition calves, or weaned heifers, are post weaned calves up to five to six months of age. They have environmental requirements similar to baby calves, and should be assembled in groups of similar age and size, with smaller groups (8 or less) used for calves coming out of individual housing.
McFarland prefers to see these younger heifers in bedded pens, since they're not producing heat like older animals do.
Once dairy replacement heifers are six months old, research supports putting them in groups by age and weight, with the maximum animals per group dictated by the dairy's management ability and calving rate. The maximum group age spread should be four months and the maximum group weight spread should be 200 pounds.
"That way, animals in the group have similar ration needs, similar healthcare needs, and they're of similar age and size, so the competition between them is not that great," McFarland explained.
A range of groups also helps provide the space needed as the heifers grow and for heat detection, breeding and pregnancy checks.
Breaking it down, McFarland suggested grouping heifers 6-8 months old and 400-500 pounds; 8-12 months old and 500-700 pounds; 12-16 months old and 900-1,100 pounds; and 20 months to one month pre-calving and 1,00-1,300 pounds.
For these heifers, the housing options include gated bedded pen shelters, gated freestall shelters ranging from 2-row to 6-row, combination gated bedded pen and freestall shelters, and gated 'self-cleaning' shelters with counter-slope or single-slope pads.
In general, the resting area requirements for transition calves and heifers is adequate space and enough clean, dry bedding to provide comfort and insulation. It should be well-drained and easy to clean and sanitize.
Heifer bedded pens allow for stocking flexibility. Bear in mind that the bedded space required per Holstein heifer increases as she grows from a minimum of 40 square feet at four months old to 80 square feet at 20 months old. This does not include the areas next to feed and water, even if they are bedded, McFarland noted.
A width-to-depth ratio of 1:2.5 will help keep the pen dry and allow for occasional overcrowding.
Bedded pens can be designed with a concrete base, for easier cleaning, or an earth base, which can provide better drainage, but should be replaced periodically.
Heifers in freestalls
Freestalls usually make more effective use of the building space and use a lot less bedding material. In this system, the number and size of stalls determines the number and size of animals in a group.
There are five suggested sizes of freestalls for animals from 300 pounds to pre-calving. "It's very important to size these groups properly," McFarland said.
If multiple groups will be housed within a building, the stall bed length is determined by the largest heifers that will be in that building. The stall structure is then tweaked to accommodate smaller heifers by adjusting the divider width and height, the neck rail, brisket locator and front barrier.
"The important thing to remember is that the stalls within a group should be selected to reflect the size of the animals leaving a group, not the animals coming into a group," McFarland stressed.
The resting surface needs to be comfortable, but it also needs to be very durable since heifers tend to paw. Mattresses or mats topped with bedding usually work very well, McFarland said.
Headlocks work very well to allow entire group restraint for vaccinations, breeding and pregnancy checks.
Give the heifers space to all eat at the same time and provide between 18- and 24-inches of feeding space per head. McFarland figures 18 inches is adequate for animals up to a year old and, beyond that, 24 inches. Closer to pre-calving, consider bumping it up to 30, he suggested.
The feed should be located away from the resting area, with the feeding surface 2-4 inches above the heifers' standing surface and 36 inches wide, smooth, durable and easy to clean. Tile, epoxy and even stainless steel sheets can do the job.
For transition calves, a slant bar feed barrier works best and, since the youngsters are still usually eating grain, put it in a trough to keep it within reach.
Once they begin eating more forages, remove the trough and use the flat manger. A horizontal bar will help keep them corralled, but be careful with self-locking stanchions which can startle or even harm the young, inexperienced animals.
If self-locking units are used, make sure to put them very low, McFarland advised, so the bar may not even close and then lock the calves up individually.
It's important to use the appropriate feed barrier for the heifer's size. "There are a number of manufacturers that make adjustable neck openings to allow flexibility," McFarland said. "We highly recommend these for the growing heifers."
Post and rail feed barriers can be tricky since putting the rail in the right place may not confine the frisky heifers, which means additional posts or rails are required. "That's why we really like to see headlocks because they help confine the animals and provide restraint and good access to feed," he observed.
Good access for water means selecting a water station that is frost-free, easy to clean and presents the water at the appropriate height. Based on heifer size, that can range from 18 inches to 32 inches.
Make sure younger calves can actually drink from the water station, which can be a problem when the station has a flap or a disk or ball. The other issue is cleanliness. "That's why we prefer trough-type waterers. They provide calves easy access to the water and they give the caregiver an easy indicator of the water quality," McFarland said.
For confident footing, use a dry, non-skid surface that is well drained and clean it regularly to prevent manure buildup. Textured surfaces with grooves closer together than for adult cows can be used, but slotted flooring is not recommended for heifers younger than six months old.
Penn State Agriculture & Biological Engineering plans for heifer housing are available at abe.psu.edu.