Housing Standards

Provide clean, dry, well-bedded, draft-free housing with good air quality and per-animal resting space allocations (Holsteins):

• Wet calves 24 hours to 60 days old – 24 square feet
• 8 to 18 weeks – 34 square feet
• 18 to 24 weeks – 40 square feet
• 6 to 12 months – 45 square feet
• 12 to 18 months – 50 square feet
• 18 months to 2-4 weeks pre-fresh – 60 square feet
• 2-4 weeks pre-fresh – 100 square feet

In free stall housing, provide one stall per animal at appropriate stall dimensions (Holsteins):

• 6 to 9 months – 30 x 54 inches
• 9 to 12 months – 34 x 60 inches
• 12 to 18 months – 36 x 69 inches
• 18 months to 2-4 weeks pre-fresh – 40 x 84 inches
• 2-4 weeks pre-fresh – 43 x 96 inches

Feeding Space Standards

Target feeding space

• 6 to 12 months of age: 18 inches per head
• 12 to 18 months of age: 20 inches per head
• 18 months of age to freshening: 24 inches per head
• 3 weeks prior to freshening: 30 inches per head

Stocking density and pen assignments

• Free-stall or open-lot housing should provide total bunk space inches to allow all animals to eat at the same time.
• Feeding systems with headlocks or slants should provide an animal:stall stocking density of 1:1, or be stocked at a rate to accommodate target feeding space above (example: heifers three weeks prior to freshening in 24-inch stalls should be stocked at 80%).
• Pre-fresh heifers should be housed separately from close-up, adult cows.

Housing Environment

Housing (indoor or outdoor) of wet calves 24 hours to 2 months of age

• Good air quality (indoor ventilation rate of 100 cubic feet per minute [cfm] in hot weather, 50 cfm in mild weather and 15 cfm in cold weather).
• Calf housing should be constructed of material that promotes optimal hygiene and should be cleaned regularly
• In group housing of wet calves, clean and sanitize feeding equipment daily.
• Constructed of materials that promote optimum hygiene and will not harbor harmful pathogens or disease (Nonporous plastic is the recommended housing material.)
• Cleaned and sanitized between calves.
• In weather below calves' normal thermal threshold, provide deep bedding material to allow calves to nest and additional nutrients to compensate for energy expended to maintain body temperature.

Housing for calves 2 to 6 months of age

• Good air quality (indoor ventilation rate of 130 cfm in hot weather, 60 cfm in mild weather and 20 cfm in cold weather)
• Skid-free footing surface
• Water intake space should be 1 linear foot for every 10 animals or at least 1 automatic waterer for every 20 animals, with a minimum of 2 waterers per group and an adequate water supply.
• Feeding space to allow all animals to eat at the same time (above for target feeding space)
• Heifers should have protection from direct sunlight any time the Temperature Humidity Index (THI) (Fig. 1) meets or exceeds:
  • 77 for heifers 6 to 12 months of age 72 for heifers 12 months of age to freshening
  • For heifers in free stall housing, provide at least one stall per animal.

Housing for heifers 6 months to freshening

• Good air quality (indoor ventilation rate of 150-180 cfm in hot weather, 70-80 cfm in mild weather and 25-30 cfm in cold weather)
• Skid-free footing surface
• Water intake space should be 1 linear foot for every 10 animals or at least 1 automatic waterer for every 20 animals, with a minimum of 2 waterers per group and an adequate water supply.
• Feeding space to allow all animals to eat at the same time (See above for target feeding space).
• Heifers should have shade any time the Temperature Humidity Index (THI) meets or exceeds:
  • 77 for heifers 6 to 12 months of age
  • 72 for heifers 12 months of age to freshening
• Heifers should have shelter from wind and precipitation any time windchill temperatures are 20°F or lower.
• Heifers 6 to 12 months of age should have overhead shelter in these conditions.
• Heifers 12 months of age to freshening should have a windbreak in these conditions.
• Housing should be cleaned and well-maintained between groups of heifers.

Isolation facilities may limit the risk of contagious disease transmission among heifers of all ages. A variety of housing plans can be viewed at https://abe.psu.edu/extension/idea-plans.

Baby Calf Housing Space Formula

Bedding, Bugs and Calves

Maintaining Comfort and Health

Jerry Bertoldo, DVM
Senior Extension Associate, NWNY Dairy, Livestock and Field Crops Team, Cornell Cooperative Extension/ PRO-DAIRY

Introduction

It is generally accepted that young “wet” or preweaned dairy calves respond to “soft” bedded housing with better health and growth efficiencies when compared to raised slats, concrete or surfaces of compacted stone fines. This is particularly true if it is “cold housing” in climates that experience extended periods of time outside of the normal
thermo-neutral zone of calves. Whether this is a result of comfort or simply not robbing energy for growth or immunity from the calf depends on the situation

Bedding surfaces for wet calves are important for varying reasons. Pathogen exposure, wetting of the hair coat, ammonia generation, comfort value, favorability to fly propagation, availability and cost should be considered in the management decisions regarding bedding choice and use. Whatever the bedding used, young calves should be each given 32 ft² of area in hutches and 28 ft² when housed in pens.

From a disease perspective, maintaining a surface that minimizes the exposure the calf has to manure and the ever present coliform bacteria is critical. This can be achieved with most any material if the amount used and the cost is not an issue. Regional conditions greatly affect what material is practical. Supply, temperature ranges and labor limitations impact material selection.

Keeping calves dry prevents evaporative cooling in cold weather and reduces the need to increase feed energy intake to avoid daily gain stall out. Calves groom themselves more if bedding material sticks to their wet hair coats. This ingested matter comes complete with an unwanted load of bacteria. The wetter the bedding near the surface, the more bacterial growth can be expected. Damp environments attract a variety of flies to lay eggs and propagate as well as increase ammonia production.

Flies represent the major pest problem for dairy calves. Lice and mange can be significant detractors of health and productivity depending on housing, season and herd conditions. Internal parasites are of minor concern where calves are housed away from older heifers and adults or dirt lots where nematode larvae have accumulated.
Unfortunately, very few scientific studies have been conducted to sort out the effects of different bedding materials. One by the University of Arkansas published in the Journal of Dairy Science in 2004 stands out and will be referenced in this presentation.

Bedding Materials

Pea gravel, crusher fines, sand, wood shavings, sawdust, straw, rice hulls and paper by-products have all been used for calf bedding. The inorganic products lack the ability to absorb moisture and do not support bacterial growth until contaminated with organic materials from the calf or feed spillage. They provide a welcomed cooling via conduction of heat from the calf during sweltering summer days, but become an energy robbing problem when temperatures fall below 60°F for less than three week old calves and less than 50°F or so for older calves. Sand is recommended as a year round bedding material in northern climates only in heifers over 500 lbs. Inorganic materials except for sand are not as comfortable as fluffier organic sources and tend to keep fecal material in closer contact with the calf.

Organic bedding sources absorb moisture to a greater extent than mineral sources. As a result, bacterial growth is supported. The addition of manure and urine enhances this
growth. Bacterial action breaks nitrogenous waste down and liberates ammonia. In studies of adult dairy cattle housing, straw and paper sources trend towards high levels of Streptococcal bacteria while wood shavings and rice hulls are supportive of coliform growth. Hay unfit for feeding is often too stemmy, needs chopping and can expose calves to respiratory allergens. Chopped hay wicks moisture and bacteria more aggressively than straw. Sand is the best material for minimizing coliform build up.

Consideration of the base on top of which bedding is placed must be addressed. Cement pads will dictate more absorptive bedding of deeper proportions and slope to direct any seepage away from the working area of a pen or hutch. Gravel works well when landscaping cloth is used to allow downward drainage without fouling the base with organic material or sand. Bedding depth recommendation range from 2 to 6 inches based on material, subsurface and weather.

Calf Behavior

Research has shown that calves spend 73-81% of their time lying down - 55% of daylight hours and near 100% at night - if they are not disturbed. Calves have a preference for “nesting” while lying down. In the cold weather this behavior conserves body heat. Straw is the preferred material for nesting as determined by its insulating properties and by observing calf activity. It appears that the standing, eating, investigating, surface contact and resting patterns do not change with bedding surfaces.

Calves groom themselves regularly spending 2.5 to 4% of the day doing so. Long straw bedding promotes the least time for grooming while a light density; small particle material such as rice hulls the most. Depending on the cleanliness of the bedding surface and hence the calf’s hair coat, ingestion of fecal pathogens can be significant with grooming.

Bedding and Health

When sufficient bedding was used to minimize visible manure, wetness, soiled hair coats and ammonia levels the type of bedding did not alter growth and health characteristics significantly in the Arkansas study. In fact, the comfort or stress levels for different bedding surfaces as determined by metabolic markers (cortisol and acid glycoprotein) did not appear to vary by bedding material. It must be understood that the study was conducted in late summer and early fall without cold stress, in individual pens inside a barn with open sides, on a newly surfaced base with well balanced diets and excellent care.

In everyday situations, the ability to tightly control the environment is a challenge. Much individual calf housing on farms of all sizes is in hutches that are outdoors. Rain, snow, runoff and dumped water buckets add to the moisture from urine and manure. Indoor housing brings ventilation problems not seen outdoors. Proximity to silage leachate, adult manure and tracked mud adds to what we expect bedding to shield calves from.

Bedding Costs

Most give wood shavings and wheat straw the highest grades for calf comfort, dryness and cleanliness over all seasons. This is achieved with the addition of fresh material two to three times a week and attention to drainage and spilled water. Availability and cost is a limiting factor for shavings and straw use in many areas.

A 2003 survey of 8 large New York dairies reported on the cost of bedding for dairy replacements entering the herd. Each freshening heifer had incurred bedding cost of $62 (4% of the $1,429 total rearing expense) or $.09 per day. On a cost per pound of gain basis, bedding accounted for $.05 per day or 4% of the total cost. Manure storage and spreading costs represented 3% of total rearing expense.

The Arkansas study used 22 lbs of straw and 49 lbs. of wood shavings per wet calf over 6 weeks. At $90 per ton the straw cost $1.01 per calf for the period. At $10 per ton the bulk shavings cost only $0.24.

Pests Related to Bedding

Flies are the number one pest that affects young calves. Lice can be a problem on farms where calves are housed adjacent to older replacements or adults. Where calves are removed quickly after birth and placed away from older animals this is not a problem. Internal parasite infection of young calves (nematodes) occurs where there is exposure to infective larvae in adult manure that is more than 2-3 days old or dirt lots used by adult cattle. Calves are not born with these infections and will not propagate transmission as wet calves as a rule. Coccidia and Cryptosporidia infections can occur if bedding is not changed or subsurface contamination is not covered well enough by bedding. Mange and ringworm are skin diseases from contact either with infected cattle or surfaces carrying the respective mite or fungus.

The house fly, Musca domestica, is the primary pest of the young calf. They do not bite, but are effective fomites or carriers of disease. There is evidence that coliforms can multiply in their mouthparts. Since these flies enter darkened buildings, homes near swarming animal areas can be inundated with every opening door. House flies complete their life cycle in a very short 10 days.

The stable fly, Stomoxys calcitrans, is the second most common barnyard pest. These normally attack the legs and bellies of cattle with piercing mouthparts to feed on blood several times a day. Foot stomping is a telltale sign of the painful bites of both the males and the females. Decreased appetites and fatigue is possible with heavy infestation. Stable flies do not enter buildings as the house fly does. They complete their life cycles in a more leisurely 3-4 weeks.

Horn flies, face flies, heel flies, horse flies and deer flies are associated with cattle on pasture and not a concern for indoor housed calves and minor problem for hutch calves. Face flies the carriers of the Pinkeye bacteria may present the biggest challenge of this group.

Limiting Fly Habitats

Both the house and stable fly breed in manure, manure piles, decaying silage, moist waste feed, bedding, wet straw and grass clippings. Straw bedding has been shown to promote greater growth of both house and stable flies than wood shavings or other commonly used material. Infestation assessment and monitoring may be accomplished by use of fly counts on animals, bait traps, sticky ribbons or spot cards.

As with all fly problems, sanitation is the key management control point. Removal of the favored breeding materials every 7 days breaks the life cycle of all flies. Keeping as little exposed wet organic matter around the farm premises as possible is ideal. Keeping manure out of muddy areas, spreading manure in a thin layer to promote drying, eliminating gaps under water tanks and feed bunks, spreading feed refusal and spoiled silage frequently are best management practices.

Fly Control

Despite the best attempts at reducing the breeding efficiency of flies there may be a point where other control methods are needed. Some flies travel distances of miles routinely. A neighbor with little regard for fly control may be exporting an airborne army in your direction.

Chemicals have been used for decades to eliminate adult flies and larvae. Long acting residual products are effective for immediate knockdown, but build resistance much faster than short term agents. Spaces sprays and baits are effective, selective and less apt to promote resistance.

Sticky tapes and ribbons can be quite effective for low to moderate infestations. Frequent changing is necessary to avoid dry, dust covered and fly saturated strips.

Biological control otherwise known as Integrated Pest Management or IPM has become more common for use against the house fly. Parasitic wasps, Muscidifurax raptor, selectively lay their eggs in the larvae of the house and stable fly effectively preventing it from developing. These are commercially raised and released on a weekly basis form mid-May into mid-August in northern states. It is important to note that only this species of wasp is effective against the house fly. Other parasitic wasp species have been promoted as such with little or no results. These host-parasite relationships are very species specific. These wasps are naturally occurring, but in numbers too low to contend with the fly numbers generated on most farms today.

In addition, there are beetles and mites that are predatory to flies. All insects parasitic to flies are subject to the same chemical control effects as their victims. Residual insecticides or larvicides cannot be used in conjunction with parasitic wasp releases. Judicious use of short acting chemicals is often necessary to supplement natural parasitic wasps.

Future study holds hope for parasitic control of other species of fly pests.

Bibliography

Lago, A., S. M. McGuirk, T. B. Bennett, N. B. Cook and K. V. Nordlund. 2006. Calf respiratory disease and pen microenvironment in naturally ventilated barns in winter. J. Dairy Sci. 89:4014-4025.

Panivivat, R., E. B. Kegley, J. A. Pennington, D. W. Kellogg and S. L. Krumpelman. 2004. Growth performance and health of dairy calves bedded with different types of materials. J. Dairy Sci. 87:3736-3745.

Rutz, D. A., C. J. Geden, C. W. Pitts. Pest Management Recommendations for Dairy Cattle. A Cornell and Penn State Cooperative Extension Publication
Schmidtmann, E. T. 1991. Suppressing immature house and stable flies in outdoor calf hutches with sand, gravel and sawdust bedding. J. Dairy Sci. 74:3956-3960.