A STUDY OF MECHANICAL GRAZING OF IRRIGATED PASTUREIN THE SOUTH SASKATCHEWAN RIVER DAM AREA*

by

R. N. Kohlert

Canada Department of Agriculture, Prairie Farm RehabilitationPre-Development Farm, Outlook, Saskatchewan

INTRODUCTIONMechanical grazing is a process by

which the feed is cut in the field,transported to the feedlot, and fed tothe animals in the green state. Thismethod is practiced on an intensivescale in Great Britain, mostly withdairy herds (2). In the United States,mechanical grazing has come intoprominence in the years 1940-1960,due to more intensive land use inmany States that have high rainfallor irrigated areas. United States reports indicate the feeding of corn asa concentrate in mechanical grazing(5). The Animal Husbandry Department of Iowa State University foundthat mechanical grazing resulted inmore rapid beef gain with a lowercost per pound of gain than naturalgrazing. One of the more promisiingmethods was the feeding of green feedwith limited grain and no proteinsupplement. This conclusion wasbased on cost of gains, early marketing date with good slaughter finish,and the most suitable usage of theforage crop (7). The University ofCalifornia tested alfalfa silage of various mixtures and additives. SudanHay, under free choice, caused littlechange in daily gain but a slight decrease in the production of beef.Barley increased gains but did notincrease beef production per acre.Molasses not only decreased gains butlowered substantially the amount ofbeef produced (4).

Kamloops workers reported reducedpasture productivity under mechanicalgrazing. Costs were higher due to increased capital expenditures for theharvesting machine and greater labourinvolved in feeding the forage (6).Lethbridge tests showed mechanicalgrazing did not appreciably increasebeef production per acre. Their results indicated that, although forageproduction was lower from the mechanically harvested fields than fromthe rotationally grazed fields, beefproduction per acre was greater. Thismay indicate that feed requirementsfor gain are lower in a feedlot whereanimals are confined than when theyare grazing on pasture (1). Severalyears of mechanical grazing at Hays,Alberta, indicated that even in a yearof low productivity of pasture andhigh labour costs, a net profit was stillrealized (3).

r-,2

With the development of the SouthSaskatchewan River the Prairie FarmRehabilitation Act wished to acquireinformation on mechanical grazing asa possible farm practise in the proposed area of irrigation development.The study was conducted to determine the economic and practical feasibility of mechanical grazing of irrigated pasture.

EXPERIMENTAL PROCEDURE

The Prairie Farm RehabilitationAct (P.F.R.A.), Predevelopment (Irrigation) Farm was chosen as the sitefor the tests. One of the regular hayfields in the farm rotation was utilizedfor the mechanical grazing trials withno control group being used.

The first phase of the test was todetermine pasture productivity undermechanical grazing conditions. Fieldtests were conducted every two weeksto determine the volume and qualityof foliage produced. Final productionvalues were later related to livestock

gains. Dry matter percentages werecalculated from replicated yield sampling of the growing foliage. Botanicalanalysis, percentage alfalfa, leafstemratio, and protein determinations wereconducted on the samples to provideadditional data with respect to thetype of feed that the steers receivedduring each two week period. Weather factors affecting forage productivity, air temperature, rainfall, andrelative humidity were recorded. Records were also kept on the irrigationand fertilizer applications.

A flail type forage harvester withshredding outlet, loading hood, andstationary deflector was used in thetest. The forage harvester was drivenby a 3-4 plow tractor with live pto.The cutting drum operated at thenecessary 1600-1700 rpm to ensure adequate delivery in the feeding box. Themechanical wagon was of the self unloading type (side or rear) with theunloading mechanism operated by thetractor pto. The mechanical wagonwas of a regular commercial type withside extensions and a screen top andback to trap the forage as it wasblown from the forage harvester.

The second phase of the study wasto evaluate the output value of pasture in terms of beef conversion basedon mechanical harvesting. Fifty-four

yearling steers, averaging 581 pounds,were randomly divided into twogroups, one of 22 and 32 respectively.The group of 22 were injected withSynovex-S (growth hormone). Thesteers were kept in the feedlot and fed,twice daily, only the green choppedgrass legume mixture from the pasture. Total field area measurements

were used to determine the carryingcapacity of the irrigated pasture. Allforage from the field was weighed andrecorded prior to feeding the animals.The livestock were individuallyweighed at regular two-week intervals.The feedlot was equipped with anautomatic watering device, free choicemineral mixture, salt and necessarybeding straws. A detailed account waskept of feeding problems with emphasis on the incidence of bloat. Detec

tion, treatment, and post-treatmentand after affects of bloat were recor

ded to provide evidence of the palata-bility and occurrence of waste ofgreen feed.

Thirdly, a detailed account of feed,labour and capital costs were recordedto determine the economic feasibilityof mechanical grazing. The currentproblems of equipment used, irrigation costs and feeding labour weretreated in detail. A time and motionstudy on the feeding enterprise wasincluded. Actual costs were estimatedaccording to the type of power andequipment units and labour requirements for the various operations.

RESULTS

Pasture Productivity

The alfalfa percentage of thebrome-alfalfa forage was 35-58% atthe first cut but succeeding secondand third cuts showed a substantialincrease in alfalfa percentage. From apasture standpoint this factor is unsatisfactory because of the high bloatdanger.

The second and third harvests consisted of a greater number of shorterand less mature brome plants. Thebotanical analysis showed the bromeplants quite high in number, yet abrome plant of 24 inches had verylittle total feed value compared to thealfalfa plants of equal height. Theheight of the forage at the beginningof cutting was approximately 16.5 in-

CANADIAN AGRICULTURAL ENGINEERING, JAN. 1965

ches and at the end of the grazingperiod (89 days) measured 8.3 inches. This gave a loss of 8.2 inches inforage stand.

Leaf-stem ratios of brome and al

falfa, percentage composition andprotein analysis were taken at thesame time as the height and botanicalanalysis tests were being conducted,with results calculated on a dry matter basis. Illustration is shown in

figure 1.2.20

100 2.00

30 i .80

30 t.60 i-

70 / -\ V' 1.40 '

GO / / /' \o C:0 ..00 5

x / .-' \ \-^f "v---'' v

.80 ^

.60

2 0 X .40

10 .to

10 30 30 40 50 SO TO 30 90

Oaya of t«at 0«oinni r»s Jun. 7

alfalfa %alfalfa leaf-stem ratio

.. ... - brome leaf-stem ratioprotein as a °/c of brome-alfalfa n iixture

Figure I. Alfalfa percenfage of mixture, brome leaf-stem ratio, alfalfa leaf-stem ratio, and percentageprotein during mechanical grazing period June 7 toSeptember I, 1962. P.F.R.A. Predevelopment Farm,

Outlook.

Coefficient of Correlation Determination (r) value of 0.83 indicatesthe variation of protein is associatedwith the variation of alfalfa percentage (r2 = .69). As the stem-leaf ratioof brome rose the percentage of protein fell (r = -.72). Fifty-one percentof the variations in protein are associated with variations in the stem-leafratio of brome. No significant difference was found in the percentageof alfalfa in the mixture on the sevendates of testing over the grazingperiod. Although a wide variation inmeans did occur not a large enoughnumber of samples could be taken toget a significant test of difference.Visual inspection showed a great variation in the percentage alfalfa in themixture over the summer period. Nosignificant difference was found in thepercentage alfalfa of the mixture between the dates of testing and locations of testing. Again the limitednumber of samples prevented establishment of a statistical basis for whatwas observed visually.

These tests indicate the need for amixture of grass and legume that willremain in a 30% alfalfa to 70% grassfor repeated cuttings during the summer months. This was the chief failureof the brome-alfalfa mixture. Theprotein content of the mixture rosedirectly as the percentage of alfalfain the mixture increased.

The mechanical grazing area wasdivided into two fields. When onefield was completely grazed it wasfree flooded with four inches of irrigation water. The other iield was

treated similarly. The fields weregiven only one 4-inch irrigation application. An average mean temperature for the summer period of 66°Fand a seasonal rainfall of 6.9 inchesmade possible the reduced irrigation.The fields were irrigated July 9-14and 16-21 respectively.

The 10.67 acres under mechanicalgrazing produced 28,150 pounds ofwet feed or 3.5 tons dry matter peracre.

Pasture Output in Terms ofBeef Conversion

The steers showed an averageweight gain of 2.03 pounds per headper day for the 89 day period. Thetwo groups showed no significant difference in rate of gain. The weightgains remained somewhat constantover the summer period. The Controlgroup averaged 2.04 lbs. gain per dayand the implanted group gain per day2.02 lbs. over the grazing period. Thefeed conversion was 7.69 pounds ofdry matter per pound of beef produced with a stocking rate of 5.06steers per acre. The beef per acre was914.81 pounds. Waste was negligible.

implanted group were equal in weightbut due to the effect of the hormone,were not as advanced on finish as thecontrol group. The Synovex - S gaveno superior weight gains over the summer period. No significant correlationwas found between beginning weightsand weight gains.

Bloat Observation and Treatment

Bloat presented the greatest problem to a successful mechanical grazingoperation. Brome-Alfalfa bloat is ofthe frothy-bloat type which builds upvery quickly within the animal andif not released within minutes ofbuildup results in death of the animal. Bloat occurred 30 times in 89days and a detailed account is givenin table 111.

The incidence of bloat appearedto be directly related to alfalfa percentage and usually occurred when thebrome-alfalfa mixture contained morethan 30-35% alfalfa. Mechanical grazing would not be considered a feasible operation under these circumstances.

TABLE I. PASTURE PRODUCTIVITY AND BEEF CONVERSION RATES OFMECHANICAL GRAZING TRIALS JUNE 4 TO SEPTEMBER 1, 1962

P.F.R.A.. Predevelopment Farm, Outlook

Number of Steers mechanically grazedPounds of beef produced over M.G. periodPounds of green feed fedPounds of green feed per pound of beefPounds of dry matter fedPounds of dry matter per pound of beefNumber of steers carried per acre Mechanical GrazingPounds of beef produced per acrePercentage waste

154

9761

300363

30.7775,090

7.69

5.06

914.81

.001

TABLE II. FREQUENCY, SEVERITY, AND TREATMENT OF BLOAT DURINGMECHANICAL GRAZING PERIOD JUNE 4 TO SEPTEMBER 1, 1962

P.F.R.A. Predevelopment Farm, Outlook

Description over summer periodJune 4 to September 1, 1962

Number of days on which bloat occurred

Total number of animals bloated

Minimum number of animals bloated at one timeMaximum number of animals bloated at one time

Average number of animals bloated at one timeNumber of animals injected directly into ruminAnimals drenched

Animals trocard following knife pierceAnimals pierced with knifeAnimals complete recoveryAnimals lost

30

Number

7 medium

14 serious9 serious

1

9

3.3'

22

1

7

7

29

1

Upon completion of tests the steerswere graded according to DominionLivestock standards. The hormone implanted group had substantially feweranimals in the "superior" group. The

Cost Analysis

The time and motion study of themechanical grazing program was broken down into separate operations as

CANADIAN AGRICULTURAL ENGINEERING, JAN. 1965.-,:!

1

TABLE III. TIME AND MOTION STUDY OF MECHANICAL FEEDINGOPERATION

P.F.R.A. Predevelopment Farm, Outlook

Time Time Average PercentageOperation seconds seconds time of

seconds total

Assemble machinery- 172 145 158.5 6.83

Travel to field 65 65 65 2.80

Cut alfalfa 562 585 573.5 24.72

Reteurn end of field to road 84 100 92 3.96

Travel to oats 109 107 108 4.65

Cut oats 93 104 98.5 4.24

Return travel to gate 150 151 150.5 6.48

Travel to yard 16 12 14 .60

Unhook and rehook 110 117 113.5 4.89

Travel to scale and weigh 65 55 60 2.58

Travel to feed yard 57 54 55.5 2.39

Unlatch wagon delivery 14 14 14 .60

Auger feed 340 304 322 13.88

Relatch wagon and remove PTO 35 30 32.5 1.40

Check cattle 90 95 92.5 3.99

Travel to yard 71 71 71 3.06

Time gain due to stopwatch supervision 300 300 300 12.93

Total 2333 2309 2320 100%

Total minutes 38.9 38.5 38.7

TABLE IV. EXPENDITURES AND RECEIPTS OF MECHANICAL GRAZINGOPERATION

P.F.R.A. Predevelopment Farm, Outlook

Expenditures

Purchase of animals—54 @ $.23/cwtaverage weight — 581 pounds

Yard feeding labour—60 hours @ $1.50Labour time due to bloat — 45 hours @ $1.50Miscellaneous labour — 40 hours @ $1.50Land use cost* $65.87/acre 10.67 acresFeed use cost $2.00/headNon-bloat veterinary supplies and servicesBloat veterinary supplies and servicesSynovex implants

2% margin for losses

Interest on investment — 6%/3 months

Receipts

Sale of animals — 54 head @ $.22/cwtaverage weight — 761.7 pounds

Manure returns — 375 tons @ $.75

Net balance

Net balance per acreNet return to overhead from land/acre from pasture rotation under—Net surplus-fland chargeMechanical grazing Number of acres

Net return to overhead from steersper head from pasture rotation—Net surplus+land chargeunder mechanical grazing Number of steers

$ 7,215.7990.00

67.50

60.00

702.83

108.00

126.78

49.36

91.15

144.32

108.24

$ 8,763.97

$ 9,049.48281.25

$ 9,330.75

$ 566.78

53.12

118.99

23.51

DplX^f rf* ? u/ay 1Pri)f1essor V*n Vliet> Head, Agricultural EconomicsDepartment, University of Saskatchewan. Opportunity cost of a ten-year rotationin operation at P.F.R.A. Predevelopment Farm, Outlook rotation

is shown in table IV. Although notmentioned in the study previously,the cutting of green oats in varyingamounts was used to mix with thebrome-alfalfa to reduce the overall

percentage of alfalfa for purposes ofcombatting bloat. The large percentage of time spent in travel, 18.49%,compared to 28.96% of the total timespent in the cutting of green feed, indicates that location of the field must

be considered in planning a grazingoperation. Also, the relatively shorttime spent in the actual cutting of theforage illustrates that a much largernumber of animals could have beenfed with very little increased labourtime. Mechanical grazing is especiallywell suited to a large feeder enterpriseas the increase in returns with increased scale would be substantial.

Difficulty is experienced in gettingmachinery small enough for a herd of50 head.

The flail type forage harvester appeared to be very well suited to thistype of operation. Only under extremely wet conditions such as cuttingduring or immediately following arain was plugging of the machine aproblem. The machine did a veryclean job of harvesting the greenforage and cutting it into desirablelengths for the livestock. The mechanical wagon proved very adaptableto the operation by cutting the feedinglabour time down to a minimum andgiving an even feed distribution withvery little waste.

The actual feeding labour per animal per day was 1.41 minutes. The netbalance per acre was $53.12 with a netreturn to overhead from land per acrefrom pasture rotation under mechanical grazing was $118.99. A net returnto overhead from steers per head fromthe pasture rotation under mechanical grazing was $23.51. Cost details areshown in table 4.

SUMMARY

During the eight - nine day testperiod the average weight gain was2.03 pounds per head per day. Hormone implants did not produce extraweight gains but did retard finish atthe completion of the grazing period.

Bi-monthly field tests of the growing forage indicated that repeatedharvesting under machanical grazing,caused a sharp rise in the alfalfa component with succeedingcuttings. Thisunfavourable aspect increased thedanger from bloat (30 cases in 89days).

54

continued on page 55

AGRICULTURAL ENGINEERING, JAN. 1965CANADIAN

SEED TREATMENT WITH THE GRAIN LOADER*

The grain loader, which is used extensively on farms for treating seedgrain, was included in previous testsof farm type seed treaters (1), and theefficiency of fungicide applicationand uniformity of distribution weredetermined. These tests did not con

sider either the possible limitations ofthis equipment as to capacity duringthe treating process, or the effect ofauger flight speed (rpm) on thequality of the treatment. Grain flowthrough a loader is seldom regulatedto a known bushel-per-hour rate during larm seed treating operations, andsince the loader itself does not provide a method for regulation, the accurate application of fungicide is possible only if some device is used todispense a known quantity of grainwithin a time limit. Tests were con

ducted to determine at what rates ofgrain flow and at what auger speedthe grain loader was most efficient asa seed treater.

The untreated grain was held in ahopper, and the grain flow, in bushelsper hour, was varied by adjusting acalibrated orifice in the hopper bottom. A 6-inch grain loader, 10 feetlong, powered by a 1-hp, 1750-rpmelectric motor, was used to mix aliquid mercury fungicide of low volatility with the seed grain. The augerspeed was varied by using four pulleysof different sizes on the auger shaftwhich gave speeds of 365, 445, 565 and780 rpm under load. The fungicidewas applied at the recommended rateof % ounce per bushel, the correctvolume being affected during any onetest by a constant level reservoir.Wheat and barley were used as testgrains. The arrangement of the equipment is shown in figure 1.

Figure I. Arrangement of equipment showing grainloader, hopper and fungicide dispenser.

The tests consisted of a series of

by

M. E. DoddsMember C.S.A.E.

Canada Department of AgricultureExperimental Farm, Swift Current, Saskatchewan

rates of grain flow from 30 to 600bushels per hour in 30-bushel increments for wheat, and 50 to 600 bushels per hour in 50-bushel incrementsfor barley. Each rate was treated atthe four auger speeds. The assessmentas to the efficiency of treatment anduniformity of fungicide distributionwas made by a procedure already described (2).

The analysis of the results of treating wheat, in the range of 30 to 240bushels per hour, showed that the efficiency of treatment and the uniformity of fungicide distribution were goodand that differences in the quality oftreatment were not significant at thefour speeds (P = 0.05). At grain flowrates of 270 to 390 bushels per hour, asignificantly poorer quality of treatment was produced at a speed of 365rpm than at any of the other speeds.The most satisfactory quality of treatment was made at 780 rpm. Thetreatment of wheat at grain rates over400 bushels per hour, at all speeds, wasnot satisfactory.

The quality of treatment withbarley at 50 bushels per hour was notacceptable at any of the four speeds.In the range of 100 to 250 bushels perhour the efficiency of treatment andthe uniformity of fungicide distribution were good at all four speeds, differences not being significant. At arate of 300 bushels per hour a significantly poorer quality of treatmentwas made at 365 rpm, and at 350bushels per hour only the treatmentsmade at 565 and 780 rpm were satisfactory. The quality of treatment anduniformity of fungicide distribution atgrain flow rates of 400 bushels perhour and over were not acceptable atany of the four auger flight speeds.

These results would indicate, then,that auger flight speed is not criticalwhen treating seed wheat or barley atgrain flow rates up to 250 bushelsper hour. At higher rates than this,and up to 400 bushels per hour forwheat and 350 bushels per hour forbarley, on auger flight speed of about800 rpm should be used. Seed treatment at rates exceeding these is notrecommended when using a 6-inchgrain loader to apply fungicide towheat and barley.

REFERENCES

1. Dodds, M. E. Fungicide Application by Farm-type Seed Treaters. Agr. Eng. 43: 340-343, 1962.

CANADIAN AGRICULTURAL ENGINEERING, JAN. 1965

2. Dodds, M. E. A Procedure forAssessing the Mechanical Application of Fungicides. Can. J. Agr.Eng. 5: 7, 1963.

MECHANICAL GRAZING

continued from page 54

Wet green feed production of 28,150pounds per acre from the 10.7 acrefield, produced 9,761 pounds of beefin 89 days. This is equivalent to 914.81pounds of beef per acre (5.06 steersper acre) or 1.0 pounds of beef per7.69 lbs. of forage (dry matter basis).

This mechanical grazing operationreturned a value of $53.12 per acreover the returns from a ten year hay,cereal, potato rotation. The net returnper head to overhead was $23.51.

ACKNOWLEDGEMENTS

The valuable assistance given by H.Van Vliet, P. J. Thair, J. E. Beamish,L. G. Sonmor.I. G. Petrie and the fullco-operation of P.F.R.A. is greatlyacknowledged.

REFERENCES

1. Clark, R. D. and D. B. Wilson,Cattleman, June 1962.

2. Farm Mechanization, June 1959Britain, pp. 214, 221.

3. Herringer, W. B., P.F.R.A. Reports, Hays, Alberta, Dec. 31,1959, Jan. 15, 1961.

4. Meyer, J. H., G. P. Lofgreen, F. K.Hart, The Value of Certain Supplements for Beef Cattle Fed Harvested Green Alfalfa, Universityof California. Reprinted fromJournal of Animal Science, Vol.'12, No. 4, Nov. 1963.

5. Montgomery, G. A., Feeders LikeGreen Chop; Feedlot: A NationalFarm Business Magazine forCattle and Lamb Feeders.

6. Nicholson: Irrigated Pasture 650Pounds of Beef per Acre, Sept.1962, Vol. 48, No. 9; PastuYeProductivity Reduced under Mechanical Grazing, Oct. 1962, Vol.48, No. 10; Country Life BritishColumbia.

7. Williams, R. W., J. M. Scholl, K.Barnes, R. Zimmerman, W. Burroughs; Westland Pasture Journal, Aug. 1954, Vol. 5, No. .3.

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