Replacement Housing (Помещения для ремонтного молодняка) (стр. 2 из 7)
Table 2. Calf and transition housing.
| Housing type | Pen size |
| 0—2 months (individual pens) | |
| Calf hutch (plus 4'x6' outdoor run) Bedded pen Tie stall (warm housing only) | 4'x8' 4'x7' 2'x4' |
| 3-5 months (groups up to 6 head) | |
| Super calf hutch Bedded pen | 25-30 ft2/hd 25-30 ft2/hd |
Table 3. Replacement heifer resting area space requirements.
| Age, months | Weight, lb | Self-cleaning resting area[3],ft2 | Bedded resting area[4], ft2 | Slotted floor, ft2 | Paved outside lot, ft2 |
| 0-2[5] 3-5 6-8 9-12 13-15 16-24 Dry cow | 100-190 190-350 350-500 500-650 650-800 800-1,200 > 1,300 | Do not use Do not use 10 12 15 18[6] 20d | 32 (4'x8' hutch) 28(4'x7' pen) 28 25 28 32 40 50 | Do not use Do not use 12 13 17 25 35 | Do not use Do not use 35 40 45 50 55 |
Table 4. Heifer freestall dimensions.
Stall width measured o. c. of 2" pipe stall dividers.
Stall length measured from alley side of curb to front of stall.
| Age, months | Weight, lb | Freestall size | Neck rail | ||
| Width, in | Length, in | Height above stall bed, in | Distance from back curb, in | ||
| 6-8 9-12 13-15 16-24 Dry cow | 350-500 500-650 650-800 800-1,200 > 1,300 | 30 33 37 42 45 | 60 64 72 78 84 | 28 30 34 37 40 | 46 49 57 62 66 |
Table 5. Suggested dimensions for post and rail feeding fences.
| Age, months | Weight, lb | Throat height, in | Neck rail height, in |
| 6-8[7] 9-12 13-15 16-24 Cows | 360-490 490-650 650-780 780-1,200 1,200-1,500 | 14 16 17 19 21 | 28 30 34 41 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 Mixed ration or grain Once-a-day feeding Hay, silage, or ration | 4 12 12 | 4 12 18 | 5 15 22 | 6 18 26 | 6 18 26 | 6 18 26-30 |
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:
Ø Less expensive to build.
Ø Less expensive to ventilate and heat.
Ø Better disease control.
Ø During cold weather, disadvantages of a cold housing are:
Ø Freezing can make manure handling difficult.
Ø Waterers must be protected from freezing.
Ø Frostbite of calves ears may be a problem.
Ø Increased feed required to maintain body heat.
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.
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.
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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.
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.
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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 Weather[8] | Mild Weather | Hot weather |
| cfm/animal | |||
| Calves 0-2 months Heifers 2-12 months 12-24 months Cow 1,400 lb | 15 20 30 50 | 50 60 80 170 | 100 130 180 470 |
| Room | Cfm | ||
| Milkroom Milking parlor, cfm/stall | — — | — 100 | 600 400 |
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.
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 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:
Ø Minimize animal handling for treatment.
Ø Allow for animal breeding.
Ø 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.
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.
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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.
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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.