TOC INDEX. Feeding Systems. Dennis Darby and Robert Borg. Take Home Message. Feed Storage

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1 TOC INDEX Feeding Systems Dennis Darby and Robert Borg Take Home Message In feedlot production, it is important to maximize dry matter intake. An important part of feed intake is the method by which feed is mixed and delivered to the feed bunk. The greatest control of intake can be achieved with a total mixed ration where feed ingredients are batched together by weight, mixed, then delivered to the cattle. The components of the feeding system are feed storage areas, a feed batching and mixing area, and equipment to deliver the feed to the pens. The mixing and delivery is usually done with truck or trailer mounted feed mixers. The four components that make up a total mixed ration are: energy in the form of rolled grain. This makes up 75% to 8% of a full feed ration; roughage fed as silage and chopped hay; supplements that include minerals, vitamins, medications. These micro ingredients are measured in parts per million, therefore they are usually mixed with a suitable carrier to form a premix; additives may include protein and energy supplements, fats, molasses and various feed by products. Feed Storage Grain is stored in conventional steel bins with a sweep unloading auger or in overhead hopper bottom bins. Rolled grain can be stored in a steel hopper bin. Two bins allow for two different types of grain. Allow for up to one day s feed requirement. Silage is stored in earthen or concrete bunker silos. Figure 1 gives silo capacities for various width and depths of silage based on actual silage densities measured in central and southern Alberta. Figure 2 is a bunker silo sizing worksheet and Figure 3 gives an example which uses the worksheet. Allow enough width to fit a feed wagon and loader at the silage face. Supplements are stored in small floor level bulk bins, as bags, large bulk tote bags, or in overhead bins. Alberta Feedlot Management Guide 3G1:1

2 Silage costs With the increase in the use of silage, a question that often comes up is, What are the costs of various storage structures?. The amount of spoilage and waste is a significant percentage of the annual cost of these structures ranging from a low of about 13% to a high of 100% of the annual costs. Table 1 is a first estimate of several different types of storage structures. These costs are based on average spoilage percentages; storing 1500 tons of silage at 60% moisture content; and using a capital cost recovery of 10% over 20 years for the structures (using 2000 material prices) and 10% over 15 years for specialized equipment (silage, bag/bale stuffers). Costs for silage valued at $28/T and $38/T are given to show the significance of the cost of spoilage/waste. Table 1. Silage Storage Cost Estimates. Annual Storage Cost ($/ton) Typical Type of Silo Spoilage % $28/ton $38/ton Ground pile (uncovered) 25+ $7.00 $9.50 Ground pile (covered) 20 $6.08 $8.08 Round pile, bale sides (covered) 15 $5.09 $6.59 Earthen trench, dirt floor (covered) 20 $6.40 $8.40 Earthen trench, concrete floor (covered) 15 $5.73 $7.23 Earthen trench, concrete floor & sides (covered) 12 $5.88 $7.08 Wooden bunker, concrete floor (covered) 12 $6.81 $8.01 Tilt up concrete bunker (covered) 12 $6.70 $7.90 Plastic bags (basis 1500T/year) 5 $10.89 $11.39 Round bale silage 10 $10.52 $11.46 Table 2. Costs of Putting up Silage. Cutting (swathing) $ $1.50/ton Chopping $ $5.00/ton Hauling (1-5 miles) $ $3.00/ton Packing $ $2.00/ton Source: Farm Operations Cost Guide; 1999; Alberta Agriculture, Food and Rural Development. Alberta Feedlot Management Guide 3G1:2

3 Obviously, these costs could change on a daily basis, but what is probably more significant is the relative cost of the various storage structures. Table 2 summarizes estimates of the costs associated with putting up silage. Feed Mixers Table 3. Sample Calculation of Coefficient of Variation. Sample Sample number value Value of (n) (x) ( x - m) n = 10 Sum x = 5.66 Sum (x - m) 2 Mean = 5.66/10 = =.566 Calculate Standard deviation = S S 2 = Sum (x-m) 2 = = n S = Calculate CV - coefficient of variation CV = S x 100 = x 100 = 4.9% m There are two major types of truck or trailer mounted feed mixers. One system uses an auger to mix the feed components, the second type uses a number of paddles. Ideally, all the feed ingredients are completely mixed. Two possible mixing problems are segregation of feed components and incomplete mixing. Segregation of feed ingredients is caused by variations in feed particle size, shape, and density. Segregation can occur during handling, by vibration caused by hauling over rough roads, and by unloading feed at bins. Fine particles fall slower due to air resistance, round particles may roll to the outside of a bin and small dense particles may vibrate to the bottom of a truck box. Remedies for segregation are: Particle size - grind or roll ingredients to a uniform size. Combine or agglomerate different size particles with fat or molasses. Particle shape - Process to a uniform shape, agglomerate different shapes together. Particle density - Agglomerate different densities of particles together. Undermixing or incomplete mixing is the other cause of poor feed uniformity. The design of the mixer and mixing time are the two main variables. There is no clear evidence that mixed feed will unmix from overmixing. Mixer Performance Feed mixer performance can be evaluated by taking several samples of feed from a batch and calculating a statistic known as coefficient of variation (CV), a measure of the uniformity of mixing. A small CV = 5% indicates uniform feed mixing while CV - 10% indicates room for improvement. Coefficient of Variation. Measure the amount of a particular ingredient in a sample. Take enough samples to be representative of the whole container. Alberta Feedlot Management Guide 3G1:3

4 Table 4. Average Coefficients of Variation. Calculate the standard deviation of the samples and the mean or average value of the samples. The CV is the standard deviation expressed as a percentage of the mean (Table 3). High roughage Intermediate High grain starter ration finisher ration Paddle mixer 4.3 % 4.6 % 5.7 % Auger mixer 3.5 % 4.8 % 14.7 % Figure 4. Maximum Mixer Fill. Alberta Farm Machinery Research Centre Trial Two main types of truck mounted feed mixers, a ribbon auger type and a paddle type, were tested in a trial by the Alberta Farm Machinery Research Centre. The auger type is the most popular among producers. (Example: auger - Harsh, paddle - Rotomix). The ration tested was barley, barley silage, molasses, and supplement (vitamins, Rumensin, Tylan, barley, oil, limestone). The coefficients of variation for this trial are shown in table 4. For this test, both mixers were equal for the starter and intermediate rations. As mixing time was held constant for this trial, perhaps a longer mixing time was required for rations with large grain concentrations. Other Causes of Mixing Inefficiency Operation of mixers beyond design capacity (Figure 4). Worn, altered, broken equipment. Options Custom Feed Preparation Two options are: (1) purchase a prepared grain and supplement ration, delivered to the farm, and fed by the owner, or (2) hire a neighbouring feedlot to deliver a complete ration to the feed bunks. Purchasing a complete grain ration from a feed mill or a neighbouring feedlot for a bunk-based feeding system requires bulk storage for the grain ration and a method for grain delivery to the feed bunks. A feeding system for silage and/or hay is also required. Alberta Feedlot Management Guide 3G1:4

5 Hiring a complete feed ration delivered from a neighbouring custom feedlot is an option for the farmer who wants to feed his own animals in a small feedlot, but can not justify the cost of a feed preparation and delivery system. This will depend on a close working agreement with a nearby feedlot operator that may have some extra capacity and time available. Farm Feed A farm feed processing centre is the most common option on cattle feeding operations. The cost, class and type of system depends on the size of business, and type of animals to be fed. The rancher who feeds out a few hundred of his own calves, or buys a few yearlings for over-wintering, has considerably different requirements than the large 10,000 head feedlot. An important principle is to have adequate power, three phase electricity or phase conversion equipment for large systems. Standby power is an option. Plan for expansion with equipment and storage facilities. Minimum facility - up to 2500 head The basic system is a small gain processing unit and a feed delivery system. Rolled grain prepared daily or weekly Hopper bin storage Feed wage (expensive for small lots) Roughage options are fenceline feeding of hay or delivering chopped hay with a feed mixer wagon. Medium level feed system Stationary roller mill Roughage, silage, supplement added to mixer wagon and delivered to feed fence or bunks. Several grain storage bins, receiving pit or leg. Large, full service feed system The full service feed centre will have several distinct components, design to operate independently, but planned to function effectively as a total system. The following components are typical of such a system (Figure 5): Grain receiving, storage and handling centre. Feed mill, including these components: roller mill, and holding bins, bulk supplement storage. Bulk overhead bins for rolled feed for rapid delivery to feed distribution trucks. Two bins are preferred to two types of grain. Bins should be sized to store at least one day s feed requirement. Alberta Feedlot Management Guide 3G1:5

6 Figure 1. Bunker Silo Data. Alberta Feedlot Management Guide 3G1:6

7 Figure 2. Bunker Silo Sizing Worksheet. Alberta Feedlot Management Guide 3G1:7

8 Figure 3. Calculation of bunker silo capacity required for 2000 backgrounding cattle, averaging 700 lbs during the feeding period and gaining 2 lbs per day. Alberta Feedlot Management Guide 3G1:8

9 Figure 5. Feed Preparation Centre. Alberta Feedlot Management Guide 3G1:9