| | | |in |

|6-8[7] |360-490 |14 |28 |

|9-12 |490-650 |16 |30 |

|13-15 |650-780 |17 |34 |

|16-24 |780-1,200 |19 |41 |

|Cows |1,200-1,500 |21 |48 |

Table 6. Feed space requirements.

|Type |Age, months |Mature |

| | |cow |

| |3-4 |5-8 |9-12 |13-15 |16-24 | |

| |in/animal |

|Self feeder | | | | | | |

|Hay or silage |4 |4 |5 |6 |6 |6 |

|Mixed ration or grain |12 |12 |15 |18 |18 |18 |

|Once-a-day feeding | | | | | | |

|Hay, silage, or ration |12 |18 |22 |26 |26 |26-30 |

Cold housing

Cold housing is the recommended system for raising replacement animals.

Cold housing building systems provide a dry and draft-free environment in

winter, and wind ventilation and shade in summer. The building is usually

uninsulated and has natural ventilation designed as an integral part of the

building. Indoor temperature follows outside temperature very closely.

Advantages of a cold housing are:

> Less expensive to build.

> Less expensive to ventilate and heat.

> Better disease control.

> During cold weather, disadvantages of a cold housing are:

> Freezing can make manure handling difficult.

> Waterers must be protected from freezing.

> Frostbite of calves ears may be a problem.

> Increased feed required to maintain body heat.

Warm housing

A warm housing system is less desirable for raising replacements.

Typically environmentally controlled systems are improperly managed

resulting in health and growth problems. The buildings are typically

insulated heavily and a controlled mechanical ventilation system delivers

fresh outside air. Properly designed inlets allow fresh outside air to be

evenly distributed throughout the entire structure.

Design mechanical ventilation systems in calf barns to provide minimum

continuous exchange of air, Table 7. Because the number of calves and young

heifers in a facility vary, design mechanical ventilation systems for a

range of stocking rates.

Calf housing (up to weaning)

Calves and young heifers are very susceptible to respiratory illness

and other diseases. Keep calves less than two months old in clean, dry,

draft-free facilities with adequate space, bedding and fresh air. Separate

calves to reduce disease transfer from nose-to-nose contact. Separate calf

groups from older animals to minimize exposure to disease organisms. Keep

calves in individual pens in an enclosed building or individual hutches

until weaning. After weaning they can be moved to small group pens.

Hutches in Cold Housing

Calf hutches have proven to be an excellent way to house calves. Only

one calf occupies each hutch. Typical hutches are 4'x8'x 4'. Fig 2

illustrates plywood construction. Leave one end of the hutch open and

provide a wire fence enclosure so the calf can move outside. Optional

tethers can be used where predators are not a problem. Seal tightly all

other sections of the hutch, except for the front and bottom, to reduce the

wind blowing through the hutch in winter. During summer, the rear of the

hutch can be blocked up 6" to allow for cross ventilation or design an

opening in the rear of the hutch with a tight fitting door.

There are also a variety of prefabricated plastic/fiberglass hutches on

the market. Hutches made of a translucent material require shade in summer.

Summer shade reduces heat stress on all types of hutches. Provide enough

shade to allow hutches to be moved.

Hutch management

Face hutch fronts south or east to provide draft protection during

winter and sun exposure during the day. Provide enough hutches to allow a

minimum of two weeks resting period after a calf is removed. Locate hutches

on a well drained area. Crushed rock or sand base provide a solid base for

bedding and lessen the possibility the hutch will freeze to the ground in

winter. After removing the calf, move the hutch to a clean site to break

disease cycles. Use enough bedding to keep calves clean and dry and to

insulate calves from the ground. To provide operator comfort, hutches may

be placed inside a well ventilated shed or structure, in effect providing a

cold housing environment in winter and shade in the summer, Fig 3.

Individual Pen in Cold Housing

Individual calf pens, Fig 4, can be used inside a cold housing

building. Pens are typically 4'x7' and removable. They provide isolation

for each calf. Solid partitions between pens and beyond the front of the

pen prevent nose-to-nose contact. A hover or cover on the back half of the

pen gives the calf additional protection in especially drafty locations.

Pens use building space more efficiently than do calf hutches, although

increasing animal density increases ventilation requirements. Place pens on

a crushed rock base or concrete floor to provide a base for bedding.

Individual pens require the same type of management as calf hutches.

Individual Stall in Warm Housing

Use individual 2'x4' stalls only in warm housing. This system requires

the least space per calf, but must be used in insulated, environmentally

controlled buildings with mechanical ventilation and supplemental heat.

Drafts, which occur in elevated stalls with open floors for drainage,

are detrimental to calf health. The incidence of calf disorders increases

in warm housing facilities after several years, due in part to warm

temperatures. Warm temperatures increase viability of disease organisms.

The facility must be adequately ventilated and sanitized on a routine

basis. Good ventilation, proper sanitation and careful observation of

calves are especially essential in warm housing systems to reduce disease.

Table 7. Dairy ventilating rates. Size the system based on total building

capacity.

| |Ventilating rates |

|Animal |Cold |Mild |Hot |

| |Weather[8] |Weather |weather |

| |cfm/animal |

|Calves 0-2 months |15 |50 |100 |

|Heifers | | | |

|2-12 months |20 |60 |130 |

|12-24 months |30 |80 |180 |

|Cow 1,400 lb |50 |170 |470 |

|Room |Cfm |

|Milkroom |— |— |600 |

|Milking parlor, |— |100 |400 |

|cfm/stall | | | |

Transition housing (3-5 months)

Moving a newly weaned calf from an individual pen to a small group

environment is an abrupt change or transition. The combination of stresses

due to new social interactions with other calves, competition for feed and

water, and a new housing system can seriously affect calf growth and

performance.

Giving special consideration to the calf's environment can make this

transition less stressful as the calf adjusts to group living and learns to

compete. Monitor calves for adequate dry feed and water intake and make

sure calves are disease free before moving them into a group pen.

Provide transition housing for calves from weaning to 5 months of age.

Maintain small groups of 4-5 calves per group with a small range in size or

age (I month maximum). Provide well bedded pens that allow 25-30 ft2 of

resting space per calf. Have fresh water available at all times. Transition

housing should provide an environment similar to calf hutches only in a

group setting. Depending on herd size and the ability to observe an

individual calf, the maximum group size would be 20 calves.

Calf Shelter or Super Hutch

Portable shelters or super hutches can provide transition housing for

calves from cold housing. A super calf hutch is designed for up to six

calves, Fig 5. An optional paved lot and addition of a fenced area can be

used with the super hutches, Fig 6. Keep the shelter well bedded and

alternate the hutch site between groups of calves. In a pasture system the

super hutch can be rotated on the pasture, Fig 7. Waterers can be centrally

located or moved with the hutch site.

Transition Barn

For herds greater than 100 milking cows, a series of 10'x24' pens can

be used in a «transition barn» for calves up to six months old, Fig 8.

Capacity for this arrangement is six animals if the feed alley is scraped

and eight animals if the entire pen is bedded.

Transition barns commonly have a 3:12 single slope roof with no

insulation. The barns should open to the south or east to take advantage of

the sunlight. The eave in the back wall is open to aid in moisture control

in the winter. During summer remove fabric or other coverings on the back

and endwalls for natural ventilation. Extend both ends of the barn 4'

beyond the pen fronts to minimize wind effects at the corners of the barn

during cold weather. Locate waterers in the feed manger line to minimize

splashed water in the bedded area.

To minimize excessive drafts in long barns, attach plywood to gates and

hang fabric from the underside of the roof down to the gate between

alternate pens. During cold weather, place straw bales along the bottom

edge of the gates to stop drafts. Remove bales during warm weather.

Calf Barn

Calf barns combine individual pens, Fig 4, and transition group pens

for calves into one building design, Fig 9. A full open sidewall with

curtain provides cross ventilation in summer and draft protection in the

winter. The upper half of the building can be a pivot door or curtain for

draft protection in winter. The lower part of the wall can have removable

panels for better summer ventilation. Air movement through the building

should be sufficient to maintain inside temperature only slightly above

outside temperature in the winter and slightly below outside temperature in

summer.

Use solid partitions between calves to prevent nose to nose contact.

Wire fences on fronts and backs of pens allow better air circulation during

warm weather, but arrange pens to keep calves from contacting each other.

In winter, use solid pen backs to provide draft protection. Hovers may be

needed in winter. Choose or construct pens that are easily dismantled for

manure removal.

Heifer housing (6-24 months)

There are several options for housing heifers after transition housing.

Regardless of housing type, group animals according to a management plan

considering nutritional, health and reproductive needs of each group. At a

minimum, a logical break in grouping is a breeding age group and a bred

heifer group.

The primary functions of heifer housing are to:

> Minimize animal handling for treatment.

> Allow for animal breeding.

> Allow for animal observation.

Even though heifers can tolerate more stress as they grow older, they

still must be protected from wet conditions, drafts, and poor environment.

In open front housing, provide group pens of sufficient depth to protect

heifers from winter winds. Solid pen partitions help reduce drafts.

Freestall Housing

Young heifers are grouped in freestall housing with stalls sized

according to age or size of heifer, Table 4. Freestall housing requires

considerably less bedding than bedded pack housing. Frequent manure removal

is required (once or twice a week), unless floors are slotted. Frozen

manure can be a problem in cold barns, but is manageable.

There are several different layouts that can be used in freestall

housing. Each alternative is suited to particular feeding and manure

handling situations. Each alternative has adequate feedbunk space, Table 6.

Freestalls can be inside with outside lots for exercise and feeding. The

trend is having freestalls and feeding included under the building roof or

confined area. Outside exercise lots may still be provided for use during

periods of good weather.

Two-row freestall barn

Two-row freestall barns are typically used for up to 100 heifers, Fig

10. Freestall length for each group in Table 4 is sized to provide maximum

comfort for the size of animal in the group. Heifers are grouped in pens

around the perimeter of the building.

Manure is either scraped automatically, the alley is slotted or

flushed, because it is not possible to move animals during tractor

scraping. When animals have access to outside runs, tractor scraping can be

accomplished. Build an 8' alley when a feed cart is used. For drive-through

feeding, a 16'-18' alley is required.

Two-row graduated freestall barn

A two-row graduated freestall barn changes the length of the freestall

in the pen by placing the curb at an angle to the side of the building.

Stalls at one end of the building are shorter than at the other end of the

building. The alley floor is sloped toward the freestall where a grated

gutter is used to remove manure. The floor slope provides a self-cleaning

floor. Stalls are bedded with chopped bedding to allow movement of the

manure and bedding through the grate. Gravity gutter, flush gutter or barn

cleaner can be used to remove manure. Building temperatures must remain

above freezing most of the time to prevent frozen manure in gutters. This

type of building requires a controlled natural ventilation system.

Two-row gated freestall

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