TOC. INDEX Feeding Pen Design. Wayne Winchell, Dennis Darby and Robert Borg. Take Home Message. Backgrounding and Finishing Feedlots. Space.

Transcription

1 TOC INDEX Feeding Pen Design Wayne Winchell, Dennis Darby and Robert Borg Take Home Message Backgrounding and Finishing Feedlots Space Good feeding pen design provides for proper space for cattle, looks after cattle and machinery traffic. Promotes good drainage, and specifies quality components including fences, gates, waterers and feedbunks (Figure 4). Feeding pen design varies according to size of cattle, how they are being fed and annual precipitation. Backgrounding pens require less area per animal, but require more feed bunk space because they are limit fed, at least for the initial start-up period. Backgrounding facilities are used to grow calves, 180 to 365 kg ( lbs) until they are ready to be put on a finishing ration in a feedlot, kg ( lbs). Weaned calves are under stress, therefore high quality facilities featuring good shelter from wind, a bedded rest area, good drainage, and quiet handling are important. High roughage diets are fed (rates of gain 0.5 to 1.0 kg/day) which will affect feeding system design. Finishing facilities are used to feed 12 to 18 month old cattle to market weight. High energy rations with a large percentage of grain are used. Again good facilities are important for animal welfare and optimal productivity. Space requirements include the pen area for each animal, ft 2 / head (square feet per head), the number of cattle per pen, feedbunk size, and pen orientation. Area Area depends on drainage and climate. More area is required for wetter climates and flatter topography. Area also depends on pen shape; the feedbunk must match the pen size. Table 1 suggests areas required for cattle on feed in northern and southern Alberta. Alberta Feedlot Management Guide 3E1:1

2 Table 1. Pen Areas Required in Alberta Feeder Operations. Area - ft 2 /head Type of Operation Northern Alberta Southern Alberta Feeder - finishing Calves - backgrounding Feedbunk space Feedbunk space varies from 6 in/head for steers on full feed to 18 in/head for animals starting on a limited ration where all eat at once (Table 2). Most feedlots compromise on 8 in to 12 in/ head, which may be crowded when all animals eat at once (starting) and more than necessary when feed is available at all times (full feed). The Canadian Cattlemen - Quality Starts Here recommends 10 in per head. Table 2. Feedbunk Length Requirements. Calves Calves to Feeders Feeders and Feeding Strategy 600 lb lb Cows to 1200 lb Feed Bunk Length (inches per head) Feed Present Most NA NA of the Time (full feed) Animals Eat All at Once (limited feed) Overall Layout One method of calculating bunk length is by considering the volume of feed consumed per day for each animal. If the animal is fed once per day, then feedbunk space x crosssectional bunk area - volume of feed/day. For example, if the bunk cross section area is 2.5 square feet, then 2.5 ft 2 x 6 in/head x 1 ft/12 in x 27 lb/ft 3 = 35 lb/day per head available if the bunk is completely filled. The other factor is cattle hierarchy and physical access to the bunk. Figures 3 and 4 suggests the overall arrangement of cattle feeding pens based on pen area and feedbunk length requirements for feeder or backgrounding pens. Waterer Location The choices of waterer location depends on: will the waterer be shared between pens? will the waterer be closer to the feed bunk or to the below pen drain? how many waterers per pen? Alberta Feedlot Management Guide 3E1:2

3 Distance From Feed Bunk. If the waterer is closer to the feed bunk, cattle approaching the waterer may have feed on their muzzle that washes into the waterer. With extra distance this will decrease. Waterers located closer to the feed alley are easier to inspect from the alley and pen cleaning may be easier. If the waterer is closer to the below pen drain it will be easier to keep the pen clean if water spills or when waterers are cleaned. With any location, install a 16 ft x 16 ft concrete pad around the water to maintain clean conditions. Slope 2% to 4%, use 4 inch thick air entrained concrete. Drain Location. The recommended location for below pen drains to handle runoff is outside the pens. This promotes the cleanest pens, best access for pen cleaning, prevents cattle Figure 1. Pen Area with Drains Inside or Outside the Pens. drinking from the drain, and makes full use of pen space for holding cattle. Traffic Patterns Pens need to be accessible for feeding during all weather conditions. Cattle moving in and out of the pens should not interfere with machinery movement. Good pen design separates feeding, runoff flow, and cattle flow. Handling Alley The best width for handling alleys is 16 ft for ease of cattle handling. A minimal 12' wide alley is too tight for a tractor for snow removal and cleaning. Alleys to handle cattle and Figure 2. Pen Gate Configuration. machinery may be 20 ft, and alleys that are used by pen riders to move cattle can be 24' wide. Alleys require rugged fences; four-rails on posts at 8 ft centres is best. Gates should be set up to close off access alleys, and be attached to rugged posts (Figure 2). Steel posts in concrete are best, but heavy-duty wood posts are okay. Alberta Feedlot Management Guide 3E1:3

4 Soils and Earthwork (Figure 5) Drainage is critical for clean pens, therefore all the pen and drain slopes need to be correct. Roadways handle weights comparable to local highway traffic, therefore, good drainage and road construction are important. Prior to construction, survey the site to establish cuts and fills required. Remember to establish permanent survey benchmarks. This is important during construction and for planning future expansion. Soil texture will affect feedlot performance. The pen surface ideally will be made of a compacted gravelly clay. Groundwater protection is usually not an issue under the feeding pen because a soil manure interface that seals the surface is created by the cattle. A flat sloping surface that has no soft spots where the cattle can create mud holes is important. Under cattle handling areas and drains provide for a high clay content soil that will prevent runoff from percolating downwards and compromising groundwater quality. A good option is compacted pit run gravel. Gravel in a handling alley can be hard for horses feet. Under feed bunks, place gravel prior to pouring concrete in place. If the foundation of the feed bunk and pad settles due to water infiltration, the feed alley roadway can be damaged. Care taken with the feed bunk earthwork saves time with feed bunk construction. Roadways Smooth, all weather roadways are essential for feed trucks. Slope the roadway from the feed bunk (1% to 3%). Compact the sub-grade to roadbed quality and cover with a 8-10" gravel base. If the roadway services two pens, provide for a centre of the roadway drain for runoff. Typical roadways may be 35' to 45' wide. Mounds A bedded mound can promote animal comfort and cleanliness. The mound should start out with only a light elevation of about 12", and build up over the winter. Orient the mound so that it doesn t interfere with pen drainage. A bedded mound started early in the winter season before the ground freezes produces a significant amount of heat. Alberta Feedlot Management Guide 3E1:4

5 Components Feedbunks Economy and ruggedness are two criteria for feedbunk design (Figures 6, 7 and 8). Two choices for materials are concrete or wood. Concrete is more rugged for the long term but requires more skill and equipment for forming and placing. Wood planks on steel post frames can be durable and economical are easy to modify or repair. Table 3. Recommended Feedbunk Dimensions (see Figure 9). Calves to Feeders Feeders and Cows 600 lb lb Cows to 1200 lb Throat Height (inches) (T) 14" - 16" 18-21" 24" Bottom width (inches) (W) Headrail height (inches) (H) Throat height Figure 9. Bunk Dimensions. It needs to be comfortable, so animals can reach the bunk floor without throat discomfort. Allow 16 in for 600 lb calves and 24 in for large cows. Throat height of 20 in is good for feedlots where animals range from 600 to 1200 lb (Table 3). Shape The shape of the feedbunk affects the volume of feed that can be held and affects the ease of cleaning the bunk and the feeding roadway. Feedbunk Fence Steel posts with plank or steel head rails are preferred for long lasting bunks. Rough 2 x 8 s make good wood plank rails. Steel head rails can be made with a spring tensioned cable or with steel rod, used oil field rod or steel highway guard rails. Concrete Aprons These are essential for ensuring clean cattle at the feed area. The width needs to be adequate for cattle to stand comfortably and be wide enough for cleaning machinery (tractor and blade). Possible apron widths are 6' to 12'. A six foot apron allows just enough space for a cow to stand on and is wide enough for a bobcat to clean. A 12' wide apron allows larger cleaning equipment and allows cows to eat and others to pass by at the same time. The slope is 2-4% (1/4 to ½ inches/foot) away from the feed bunk. Alberta Feedlot Management Guide 3E1:5

6 Table 4. Example Bunk Costs. For concrete, specify 25 Mpa, air entrained concrete. If you install control joints, set them at a slight angle so the cleaning blade does not catch. An alternative to concrete aprons that could be considered for short term use backgrounding or finishing pens, on well drained sites, is to use wood shavings. Three to four inches of shavings appear to prevent punch-out for up to 3 months. A second application will likely be required. Bunk Cost Concrete Bunk Concrete: 4.0 ft Rebar steel: 5.0 $ x 8 head $.80/ft.80 Steel posts 1.00 Total: $15.00 Wood Plank Bunk Concrete: 2.0 ft x 6 head $.60/ft x 8 head $.80/ft.80 2 Steel posts 1.60 Total: $14.00 Figure 10. Geogrid Construction. The four options for feedbunk cost are: Pre cast bunks, may cost $140 per 10 ft, $10-20 delivery cost per section. Cost - $16/ft, without fence. Slip formed concrete formed in place. ($3.50/ft labour plus $11/ft concrete at $110/cubic metre). Cost = $14.50/ft. Concrete cast in place, bunk, with fence, $14/ft (concrete $100/cubic metre). Built-in-place wood bunk with concrete base and with fence, $14/ft (lumber $600/M). Typical costs are calcuated in Table 4. Material cost for wood and concrete bunks is similar, as shown by the materials list. Though farm based labour will also be similar for either wood or concrete, labour for constructing forms may be nearly as much as that for building the entire bunk of wood. The main challenge for building concrete bunks is to purchase, borrow or rent suitable forms. Custom feedlot contractors are using slip forms for continuous pouring in one operation. Plastic Geogrid Table 5. Gravel Requirements Over Plastic Geogrid. Muddy or problem pen areas around bunks, waterers, or alleys can be stabilized with geogrid and gravel. Remove the mud, lay down the plastic grid; cover it with a well graded crushed gravel (particles of 1.5" or smaller with no more than 10% fines), then place a 6" layer of clay. To anchor the grid around concrete pads, dig a trench 2' wide by 14" to 18" deep around the pad. Put the end of the plastic roll into the trench, cover with gravel to anchor the end, then unroll the rest of the grid over the ground. Soil Condition Firm Soft Very Soft Well Graded Crushed Gravel cattle and equipment 6" 8" 10" trucks, heavy equipment 6" 10" 15" Alberta Feedlot Management Guide 3E1:6

7 Fences Four types of fences are used in feedlot (Figures 11 and 12): Feed bunk fences consisting of two rails or cables. Pen divider fences - four rails is most rugged, three rail minimum Rail fence with a wind break. Handling alley fences. Wind Protection Winter is the time of year when all outside animals are exposed to cold temperatures. This is drastically compounded if there is any amount of wind. Table 6 illustrates the effective windchill temperatures for various air temperatures and various wind speeds. Figures 11 and 12 illustrate typical windbreak fencing. Table 6. Wind Chill as a Function of Temperature and Wind Speed. Wind Actual Air Temperature ( C) Speed (km/h) Windchill Factor Little Danger Increasing Danger Great Danger (Death in younger animals) Gates Gates located at the top of the pen provide access for pen cleaning while gates at the bottom provide access to the cattle handling alley. If horses are used, the gate latch is located at a point easily reached by pen riders. Use a herringbone arrangement to provide for easy flow of cattle and equipment. A slid panel provides a visual barrier to the cattle. Lighting Lighting in feedlots is desired mainly for the convenience of the operator, for inspecting pens and handling cattle. Security and predator control are other advantages. The value of Alberta Feedlot Management Guide 3E1:7

8 Table 7. Lighting Requirements for Hazard Detection. Hazards Requiring lux foot normal Visual Detection candles activity Slight low 11 1 high High 22 2 low 54 5 high Source: Lighting Handbook, Illuminating Engineering Society of North America. Table 8. Feedlot Light Level Recommendations. lux foot candles along bunk 10 1 rear of pens security Source: Cattle Feeding: A Guide to Management. Table 9. Feedlot Lighting Examples. Lamp Size (HPS) Lighted area 1 Lux Foot Candles 2 x 200 W 320' x 450' ,000 sq ft 1 x 250 W 530' x 500' ,000 sq ft 1 Lamps located along feedbunk, every second pen. lighting for feed efficiency and cattle performance has not been proven. Yard lights should therefore be located over pen lines nearest handling alleys and/or waterers. Wiring for lighting can be run in water line trenches. Underground is preferred to overhead for safety and maintenance. Light levels are measured in lux or foot candles. The power and type of the lamp (Watts) determines the brightness. The height of the lamp above the ground and the lamp spacing determines the uniformity and distribution of light. Colour may be important for identification of different coloured ear tags. Colour is described by a colour rendering index (CRI). (CRI = excellent, good, fair, 0-50 poor). Feeding Pen Lighting Recommendations Use high pressure sodium (HPS) or low pressure sodium (LPS) lamps mounted on poles 30-35' high, two 200 W or 200 W lamps per pole. Choose HPS lamps ( golden - white light) with colour improved characteristics, CRI = 60 or higher if colour rendition is important (typical HPS lamps: CRI = 21,32,65 or 70). The trade off is better colour but poorer lamp life and efficiency. If colour rendition is not a factor, low pressure sodium lights (LPS) are the most energy efficient of all the light sources. The light is yellow, you will be able to distinguish shades of grey only. Strive for a light uniformity ratio of 1:3 minimum to average light. Space lamps at up to 6 times mounting height. Use IES type III medium distribution roadway lamps (luminaires). Alberta Feedlot Management Guide 3E1:8

9 Figure 3. Dimensions of Feeding Pens. Alberta Feedlot Management Guide 3E1:9

10 Figure 4. Overall Layout of Cattle Feeding Pens. Alberta Feedlot Management Guide 3E1:10

11 Figure 5. Feedlot Earthworks. Alberta Feedlot Management Guide 3E1:11

12 Figure 6. Feed Bunk Plans (see Table 3 for dimensions). Alberta Feedlot Management Guide 3E1:12

13 Figure 7. Feed Bunk Plans. Alberta Feedlot Management Guide 3E1:13

14 Figure 8. Fenceline Feeder for Large Round Bales. Alberta Feedlot Management Guide 3E1:14

15 Figure 11. Fence Details. Alberta Feedlot Management Guide 3E1:15

16 Figure 12. Portable Windbreak Fencing. Alberta Feedlot Management Guide 3E1:16