THE UNIVERSITY OF CALIFORNIASIERRA FOOTHILL RESEARCH & EXTENSION CENTER

Presents:

Annual Beef & Range Field Day

COSPONSORED BY:

UNIVERSITY OF CALIFORNIA COOPERATIVE EXTENSIONDEPARTMENT OF ANIMAL SCIENCE, D.C. DAVIS

DEPARTMENT OF AGRONOMY & RANGE SCIENCE, D.C. DAVISDIVISION OF ECOSYSTEM SCIENCES, D.C. BERKELEY

APRIL 16, 1998

In accordance with applicable Federal laws and University policy, the University of California does not discriminate in any ofits policies, procedures or practices on the basis of race, religion, color, national origin, sex, martial status, sexualorientation, age, veteran status, medical condition, or handicap. Inquires regarding this policy may be addressed to theAffirmative Action Director, University of California, Agriculture and Natural Resources, 300 Lakeside Drive, 6th Floor,Oakland, CA 94612-3560, (415) 987-0096.

TABLE OF CONTENTS

Forage Quality Varies Throughout the YearRoger Ingram and Dave Pratt 1

Visual Guides to Annual Range Forage QualityBill Frost, Mike Connor and Neil McDougald. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 4

Strategic Supplementation of Range Beef Cows: Split Feeding by Body Condition andStocking RateJames W. Oltjen 7

Efficacy of Florfenicol for the Treatment of Naturally Occurring Infectious BovineKeratoconjunctivitis (Pinkeye)J.A.Angelos, E.L.Dueger, L.W.George, T.Carier, J.Mihalyi, S.Cosgrove, J.Johnson .. 14

Demonstration of Beef Cattle Marketing AlternativesLarry Forero, Glenn A. Nader and Mike Connor . . . . . . . . . . . . . . . . . . . . . . . . . .. 15

Supplemental Feeding of Beef Cows on Two Forage LevelsMike Connor and James W. Oltjen 17

Grazing Effects on Spring EcosystemsBarbara Allen-Diaz 19

Panel Discussion: Controlled GrazingViewpoint of David Pratt and Roger Ingram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Panel Discussion: Grazing Management Strategies for Annual RangeJames Bartolome 27

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Forage Quality Varies Throughout the Year

Roger Ingram, F,um Advisor, UCCE Nevada/Placer CountiesDave Pratt, Fann Advisor, UCCE Solano County

The Sustainable Ranching Research and Education Project has been conducting monthly foragesamples on annual rangeland and irrigated pasture since July 1996. These results are used informulating a mineral supplement which accounts for forage deficiencies - except energy. Energy isprovided by the land and the cow in the form of stored body fat. This approach helps in keeping yourdirect costs with regards to feed to a minimal level.

Samples are gathered and sent in to a forage lab in New York state. Samples are analyzed forprotein, energy, calcium, phosphorous, magnesium, potassium, sodium, iron, zinc, copper,managanese, and molybdenum.

Net energy content of forage on rangelands peaked at 0.70 McaVlb in March 1997 and dropped to0.39 Mcafllb in August. Crude protein also peaked in March at 21.5% and was lowest in October 1997with 3%. Net energy content of forage on irrigated pasture varied between 0.51 Mcafllb and 0.67 Meallib. Crude protein varied between 13.2% and 18.5%. This information is summarized in graph form onthe following pages.

. ed in this table'I dfTrace mineral compOSItion 0 range an are summanzCa P Mg K Na Fe Zn Cu Mn Mo S% % % % % ppm ppm ppm ppm ppm %

Jul-96 0.38 0.16 0.16 0.66 0.029 162 27 8 40 1.1 0.104Aug-96 0.42 0.11 0.18 1 0.02 571 31.5 7 125 1.25 0.078Sep-96 0.42 0.11 0.18 1 0.02 57.1 3.2 7 125 1.3 0.078Oct-96 0.43 0.09 0.1 0.15 0.07 357 17 6 77 1.3 0.071

Nov-96 0.33 0.06 0.08 0.22 0.02 186 21 6 73 1 0.047

Dec-96 0.39 0.16 0.13 1.5 0.02 305 28 8 74.5 1 0.164Jan-97 0.51 0.12 0.16 0.74 0.03 3010 26 11 199 3.2 0.144Feb-97 0.51 0.33 0.34 3.81 0.29 273 79 16 111 1.4 0.314Mar-97 0.69 0.32 0.25 3.93 0.065 882 44.5 11 167 1.6 0.321Apr-97 0.48 0.24 0.2 2.39 0.06 134 26 7.5 82 1.2 0.185

May-97 0.56 0.31 0.25 2.01 0.09 177 34 10 75 1.8 0.156

Jun-97 0.56 0.13 0.2 1.38 0.08 100 33.5 5.5 68 1 0.123

Jul-97 0.34 0.1 0.17 0.91 0.117 120 18 6 53 1 0.104

Aug-97 0.4 0.06 0.11 0.78 0.043 261 22 6 87 1 0.056

Sep-97 0.39 0.11 0.15 0.42 0.104 309 41 11 119 1.1 0.059

Oct-97 0.27 0.05 0.11 0.26 0.049 703 22 7 68 1.7 0.045

Nov-97 0.6 0.18 0.19 1.91 0.027 2310 33 12 135 2 0.224

Dec-97 0.55 0.27 0.2 3.12 0.031 206 23 10 84 1.5 0.254

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24

Rangeland Forage Qualityfor Crude Protein and Energy (Nem)

Nem 1997

-~-~I 0.8II

I

Crude Protein 1997

3 -j----- .... ~ I 0.1

21 -I • =--- £~ ~ 0.7

6 I ~ lIIi:: ~ I , I 0.2

-~ "/"r 0.618" I \ .,. * • ... ~ ~,

I Hem 1996 0.5_I ~c 15 i- -- 'J ~.- , " ...... u

~ : /r 04~~ --- EG> -.-- Ul

-g 0.3 2

~

~ 9 I

If\)

I

o I I I I I I I I I I 0

Jan Feb Mar Apr May Jun Jut Aug Sep Oct Nov Dec

Months

. d' h' bll f" d tTrace mmera compos! Ion 0 Irngate pas ure are summanze In t IS ta e:Ca P Mg K Na Fe Zn Cu Mn Mo S% % % % % ppm ppm ppm ppm ppm %

Jul-96 0.73 0.51 0.41 3.74 0.03 293 31 8 298 1.3 0.239

Aug-96 0.95 0.47 0.51 3.66 0.016 281 44 11 317 1.5 0.255Oct-96 0.66 0.29 0.3 2.24 0.032 572 31 9 247 1.6 0.198

May-97 0.61 0.43 0.27 3.89 0.025 167 43 11 188 1.7 0.266Jun-97 0.65 0.29 0.34 3.17 0.028 200 26 7 216 0.5 0.221Jul-97 0.69 0.44 0.39 3.72 0.025 604 34 11 246 1.3 0.276

Aug-97 0.9 0.45 0.45 3.6 0.032 292.5 35 10.5 256 1.3 0.246Sep-97 0.75 0.47 0.42 4.02 0.013 244 40 11 216 1.3 0.252Oct-97 0.72 0.37 0.35 3.35 0.025 224 37 11 208 1 0.278

Irrigated Pasture Quality

20for Crude Protein and Energy (Nem)

0.8

180.7

16

0.614

i 120.5 -.ae s

D. NEm ~

~10 0.42-.Ii

~ 8 z~ 0.3

60.2

4

0.12

1996 • 1997 •0 0Jul Aug Oct May Jun Jut Aug Sap Oct

For more general information about the Sustainable Ranching Project, visit our web page atwww.foothill.netl-rjngram. The project site is also available for tours. Contact Roger Ingram (530-889­7385) or Dave Pratt (707-421-6790) for more information.

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Visual Guides to Annual Range Forage Quality

Bill Frost, Natural Resources Advisor, UCCE EI Dorado CountyMike Connor, Superintendent, UC Sierra Foothill Research & Extension CenterNeil McDougald, Watershed, Range & Livestock Advisor, UCCE Madera County

Nutritional levels of range forage vary considerably throughout the year. This is especially true forthe annual rangelands of the California foothills. Figures 1 and 2 demonstrate this variability.

Nutritive requirements of beef cattle and other livestock also vary greatly throughout the year basedon the animals' age and where she is in the production cycle. Pregnant, non-lactating beef cows, forexample, require about 1.5 pounds of protein and 9.5 pounds ofdigestible energy per day, whiletheir requirements increase to 2.5 and 14 pounds for protein and energy, respectively, after calvingand until breeding.

Economically balancing the nutritive requirements of livestock the nutrients supplied by rangeforage is a major challenge for producers. This discussion focuses on a study with the objective ofproviding photo descriptions of range forage appearance related to forage nutritional quality. Thesevisual cues to forage quality are expected to give managers general guides to forage quality whichcan be used in decisions regarding supplementation ofcattle or livestock.

We sampled forage in open rangeland at four locations: Sierra Foothill Research and ExtensionCenter, cooperators' ranches in EI Dorado and Calaveras Counties and at the San JoaquinExperimental Range in Madera County. Most samples were in sites supporting predominantlygrasses. The only forbs in substantial quantity were clovers. Samples containing large proportionsof clovers were noted and considered separately.

We sampled at times during the year representing the six following general phenological (plantmaturity) stages:

Inadequate green growth - forage plants have germinated but are growing slowly (usually duringNovember, December, and in the north, January)

Spring flush - rapid growth period (often January through March, but dates vary with the season andlatitude)

One-half green, one-half dry - plants are beginning to mature; some species and locations will exhibitdrying vegetation, some will still be green (spring, dates vary with season and location)

Peak standing crop - plants have matured; seeds have not yet shattered (dates vary with season).

Midsummer - plants have matured, seeds have shattered (usually by mid - June).

Early fall - forage has deteriorated during the hot summer; usually just before the fIrst fall rains(September).

Color photographs were taken at each sampling. Samples were analyzed in the laboratory for crudeprotein (CF) and acid detergent fiber (ADF). Protein levels in forage tend to be correlated with

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levels of other important nutrients such as phosphorus and vitamin A. These nutrients are highest inyoung forage plants and decline as plants mature. The less digestible portions of the plants, fibersand especially lignin, are represented in this study by ADF. This measure of poorer quality forage islower in young plants and increases as plant become mature. As the indigestible fiber and ligninfractions of the plant increase, the digestible energy content diminishes.

The results of our study were as follows:

Inadequate greenSpring flushHalf green, half dryPeak standing cropMid summerEarly fall

Protein(%C.F.)

13.5%13.5%8.3%6.2%6.7%5.6%

Fiber(%APF)

45%29%36%44%47%52%

The results were consistent among the three locations studied when based on stage of plantmaturity, although the date that plants reached a comparable stage of maturity varied among thelocations. These results generally agree with previous research. According to the literature,analysis of herbaceous range plants in the early leafstage resulted in higher CF levels (20% andmore) and lower fiber (below 30%) than we show for the inadequate green period. Our samplescontained a mix ofyoung green vegetation and residue from the previous year's growth and, thus,more nearly represent forage available to livestock.

Protein levels drop rapidly following the spring flush of growth and this reduction continues untilplant mature (peak standing crop), but the levels are maintained fairly well through the summer.Fiber increases (and digestible energy decreases) steadily as the plants mature and through thesummer as the more digestible portions of the plant break down. These results are similar to thoseshown by Morris and Delmas (Figures 1 and 2).

Photo descriptions of range forage that are related to forage nutritive quality at various phenologicalstages should provide assistance to mangers making decisions regarding stocking rates and feedsupplementation for livestock.

Other Reading:

IR Dunbar and M.R George, 1986. Range Nutrition on California Annual Grasslands. Dept. OfAgronomy and Range Science, University ofCalifornia, Davis, Range Science Report No.5.

IG. Morris and RE. Delmas, 1980. Seasonal Variation in the Nutritive Nature of California RangeForage for Cattle. Proc; Beef Cattle Day, University ofCalifornia, Sierra Foothill Range FieldStation, pp. 16-20.

-5-

Figure 1. Seasonal variation in crude protein (%) in range forage samples collected byesophageal fistulated steers at Sierra Field Station. (From Morris and Delmas, 1980.)

20

i!." IS

ZWi...0ItGoUI 10 -0;:)ItU

S

1173.lUll,,7. ,,­tt,.

YEARS

.lUll Dec

tt"

Figure 2. Seasonal variation in organic matter digestibility (%) of range forage samplescollected by esophageal fistulated steers at Sierra Foothill Range Field Station. (From Morrisand Delmas, 1980.)

•

~

~70

!:~

!......UICIQIt 10UI......'C~

ui'CCI soIt0

~ _ h ~ ~ • ~ ~ ~ • h ~ ~ • h ~

1173 117. "7' 1'" "77

YEA'"

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Strategic Supplementation of Range Beef Cows:Split Feeding by Body Condition and Stocking Rate

James W. Oltjen, CE Management Systems SpecialistAnimal Science Dept, University ofCalifornia, Davis

Introduction

This paper describes three years research aimed at identification of optimal strategies forsupplementary feeding of beef cows. Such strategies must maximize use of forage, promote highreproductive and lactation performance, and maintain range condition. The objectives ofsupplementary feeding on range are to supply nutrients which are deficient in the forage and arelimiting animal production, and to maximize enterprise profits. The level of supplementary feedingshould never exceed the point where the cost of the last unit of supplement equals the economicvalue of the production response it produces. While we know a great deal about the need forprotein, energy, mineral and vitamin supplementation, we have inadequate information regardingthe minimum amount and timing of supplementation required to insure economical cow herdperformance.

Past studies have not provided sufficient information about critical management variablesand their interactions. The complexity ofanimal responses, superimposed on variation in foragesupply and time lags of months between nutritional stress and reproduction preclude simpleanalyses and predictions. This study attempts to quantify these responses.

Body Condition and Supplemental Feeding

For years, cattle producers have recognized the important relationship between the bodycondition of their cowherd and reproductive efficiency. Body condition scoring quantifies thisrelationship by placing a numeric score on the relative degree offatness or energy reserves that isobserved or palpated. Body condition scoring can be used by cow-ealfproducers to monitornutrition programs as forage conditions and nutrient needs change. We have used a body scoringsystem of 1-9 (Table I). Previous research has found that cows should have good body conditionat calving to ensure good reproductive performance. Those in lower condition with a score of 5 orless at weaning may require a higher plane ofnutrition relative to their better-eonditioned peers.

Separating the cowherd by body condition and feeding each group according to specificrequirements is one "strategic" supplementation method that may significantly increase theefficiency ofa supplementation program. With this supplementation strategy nutritional needs canbe better targeted, thereby allowing the producer the option of using a variety ofenergy-eontainingfeedstuffs and/or better quality pasture to realize weight gains necessary to improve bodycondition, while feeding the cows with abundant flesh (body condition greater than 5) with lowerquality forages to maintain condition through calving. In order to ensure cows have a bodycondition score ofgreater than 5 at calving, this strategy must be implemented several months priorto calving. Waiting too long to take action to improve body condition is cost prohibitive and, insome cases, impossible. Producers must recognize that calving through rebreeding is the mostcritical period in the beef cow's production cycle, with energy requirements at their peak. For

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example, the average cow needs approximately 40 percent more energy and over 60 percent moreprotein during this period than when dry. Typically, the cow loses approximately 120 to 140pounds at calving which should be partially regained 60 to 80 days after calving. Furthermore, shehas to produce adequate milk, undergo uterine involution and meet her maintenance requirements.On the downside, there are factors cow-ealfproducers must ponder ifconsidering split-feeding asan alternative supplementation strategy. Split-feeding the cowherd into multiple groups requiresadditional pasture, fencing, and water that must be conveniently located.

Experimental Procedure

This experiment is aimed at examination of interactions between cow condition, time ofyear, grazing intensity (stocking rate) and feed supplementation. To this end, threesupplementation strategies (none, standard and strategic) are used in conjunction with two stockingrates (moderate and heavy, Table 2). Stocking rates are maintained during the critical green forageavailability time of year, late Fall and Winter. Type of supplement fed and specific time ofsupplementation are shown in Table 3. Cows enter the trial when they have weaned their first calfon June 1 each year. Standard management practices are observed, with open cows culled.

Measurements are aimed at definition ofchanges occurring in the cattle and onproductivity and economic efficiency. As cows are moved from a paddock, residue levels arerecorded. Cattle measurements include body weight, condition score, and ultrasound backfat atvarious times throughout the year (Table 3). Reproduction (post-partum anestrous interval,conception and calving rates, dystocia) and production (weaning weights) are also monitored. Allinputs and outputs are recorded to enable valid economic analyses.

Results

Complete data are available for three years ofthe study, and several more years ofdatacollection are necessary before one may place full confidence in the results. Although there hasbeen significant year-to-year variation, 59% ofthe cows (Figure I) in the strategic supplementationgroup were in adequate condition and received no late summer supplementation (Aug. 16 - Sep.30). In October all cows were placed on Heavy or Moderate stocking rate treatments. In thestrategic group, low body condition resulted in 45% ofthe cows not supplemented in the latesummer and 84% of the summer supplemented cows to be assigned to autumn supplementation(Oct. 1 - Dec. 31). Clearly cows in good condition in late summer tend to remain in goodcondition, but only 16% ofthose in poor condition gained condition with protein supplementationduring the dry summer feed season. However, nearly all cows needed winter supplementation, only1.4% ofcows in the strategic group were in adequate condition to not be placed in thesupplemented group.

Pregnancy rate was not affected by supplement treatment for cows on the moderatestocking rate (Table 4); however, cows not supplemented and stocked heavy had only 64.7%chance of becoming pregnant compared to 77.5 and 73.8% for the standard and strategicsupplementation treatments, respectively. Cows in the strategic group had pregnancy rates whichdiffered by 6.7 percentage units between high (>5.25) and low «5.25) condition scores, comparedto 19.5 and 17.6 percentage units for the other supplement treatments (no or standard,respectively). It appears that body condition score at calving for cows on the strategicsupplementation treatment was not as influential a variable on subsequent pregnancy rate. Thissuggests that strategic supplementation may be beneficial and has promise.

-8-

Calfweights at weaning were 13 and 21 lb greater for cows stocked moderately than for those at theheavy stocking rate for no or strategic supplementation, respectively. Stocking rate had no effect on standardsupplemented cows. Body condition score at calving and supplementation treatment interacted as well, withcalves on fatter cows undergoing no or strategic supplementation weighing 15 to 22 lb less at weaning, whilefatter cows on standard supplementation weighed 21lb more at weaning. This fmding is difficult to explain,and further data in this long-term experiment should prove helpful.

Table 1. Condition scoring system for beef cows.

Score Appearance

1 Severely emaciated

2 Emaciated

3 Vel)' thin

4 Thin

5 Moderate

6 Good

7 Vel)' good

8 Obese

9 Vel)' obese

Description

All ribs and bone structure easily visible, no visible or palpable fatdetectable over spinous processes, transverse processes, hip bones or ribs.Tail-head and ribs project quite prominently. Animal has difficulty standingor walking.

Tail-head and ribs are less prominent. Individual spinous processes arerather sharp to the touch but some tissue cover exists along the spine.Animal not weak, but no fat detectable.

Ribs are individually identifiable but not so sharp. No fat on ribs, brisket,spine and over tail-head, with some tissue cover over dorsal portion of ribs.Individual hind quarter muscles easily visible, spinous processes apparent.

Spinous processes can be identified individually. Ribs and pin bones areeasily visible and fat is not apparent by palpation on ribs or pin bones.Individual muscles in the hindquarter are apparent.

Ribs less apparent, less than .5 cm fat. At least 1cm fat on pin bones. Lasttwo or three ribs felt easily. No brisket fat. Hind quarter individual musclesnot apparent. Area on either side of tailhead now has palpable fat cover.

Smooth appearance throughout. Some fat deposition in brisket. Individualribs are not visible. About 1cm offat on the pin bones and on the last twoto three ribs. Fat evident around tailhead.

Brisket full, tailhead and pin bones have protruding fat deposits. Backsquare. Indentation over spinal cord. Between 1 and 2 cm fat on last two tothree ribs. Some fat around vulva and in crotch.

Vel)' fleshy and over-conditioned. Back vel)' square. Protruding depositson tailhead and pin bones. Brisket distended. Neck thick. Large spinal cordindentation. 3 to 4 cm fat on last two to three ribs.

Extremely wasty, patchy and blocky. Tail-head and hips buried in fattytissue. Bone structure no longer visible and barely palpable. Motility maybe impaired.

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Table 2. Experimental groups.

Treatment Description

Supplementation

None

Standard

Strategic

No supplement given

Supplement fed during entire dry feed season

Supplement given only to meet condition targets

Stocking rate (Nov. 16 - Feb. 28)

Moderate ca..75 cows/acre; >800 lb/acre residue (Oct. 1)

Heavy ca. 1.0 cows/acre, 625-800 lb/acre residue

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Table 3. Supplement Application Design.

SUDDlement Anotied

Item JunI-AuglS Augl6-Sep30-~--

Oct1-Nov15 Novl6-Dec31 1 Jan l-Feb2S I Marl-May31

I-4

-4I

SuppJemenJation

NONE

STANDARD

STRATEGIC

Body conditionscore & weight

None

None3

None

Aug 15

None None2 Nonel Nonel None

Protein! Protein2 Alfalfa Alfalfa None

None Nonel None2 None2 NoneProtein3 Protein2 Alfalfa Alfalfa---None

Sep30 Dec 31 May 31

1Allocate cows at two forage availabilities. moderate and high..2ff fomge availability is less than 625 Ibfacre. supplement to achieve minimal forage intake.3CoWS which have weaned their first calfare grazed on irrigated pasture in the supp!emented groups.4COWS allocated to strategic supplementation are assigned their supplement based on a model at each body condition scoring date.

Table·to Effect of Suppl('ment TI'eatment and Stocking Rate on Subsequent PregnancyRate lllld Calf Weaning Weight.

Stocking Rat~

Supplem~nt Tr~atm~nt !\'lod~rat~ Heavy

None

Pregnancy Rat~, ~o

74.03b 64.7"

Calf Weaning Weight, Ib

4473 426"

Standard

Strategic

None

Standard

Strategic

77.5 3

75.93

4423

4433

77.53

73.8ab

445·

430"

·"Means without a common superscript differ (P<.05).

Tllbl(' 5. Effect of Supplement Treatment and Condition Score at Cahing onSu!lst'quent Pregnancy Rate and Calf Weaning Weight.

Calving Condition Scor~

Supplement Treatment

None

S1andard

Strategic

None

Standard

Strategic

<5.25 >5.25

Pregnancy Rate, %

54.7d 74.23"<

82.83

77.5 3"

CalfWeaning Weight, Ib

434"< 419<

433< 4543

4463b 424<

3b<dMeans without a common superscript differ (P<.05).

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Figure 1. Sch~matic of average proportion of cows requiring supplementation (Sup)during experimental periods oyer tlm~e years. Cows not supplemented aredesignated NS.

STRA TEG/C 8/16-9/30SLlpplemented 59%

10/1-12/3168%

1/1-2/28990/0

__________ 1 NS

100 Cows

23 NS- _---~---..

18 Su p.------..

22Sup

18 Sup

-. ~ 10NS ~ 10Sup

59 Sup ______

49 Sup--- 49 Sup

Average CalvIng Date

November 11

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Efficacy of florfenicol for the treatment of naturallyoccurring infectious bovine keratoconjunctivitis (pinkeye)

lA. Angelos, E.L. Dueger, L.W. George, T.Carrier, J. Mihalyi, S. Cosgrove, J. JohnsonSchool ofVeterinary Medicine, University ofCalifornia, Davis

A randomized double blind controlled clinical field trial was done to determine theeffectiveness of florfenicol for the treatment ofnaturally occurring infectious bovinekeratoconjunctivitis (ffiK; pinkeye). One-hundred-fifty calves between 4 and 12 monthsof age at 4 separate field locations were enrolled in the study between July throughAugust 1997. On day 0 all calves were evaluated for the presence ofcorneal ulcers andmicrobiologic cultures ofboth eyes were obtained. All eyes with ulcers werephotographed and scored according to maximal diameter of the ulcer (0 ifno ulcer; 1 ifulcer:::; 0.5 cm; 2 if ulcer > 0.5 cm; 3 if perforating corneal ulcer). Corneal ulcer scores,clinical signs, and corneal ulcer surface area measurements (SAM) were determined every48 hours through day 20. Calves were assigned to one ofthree treatment groups: a singlesubcutaneously administered dose of florfenicol (40 mg/kg) on day 0 (SC group); twointramuscular injections of florfenicol (20 mg/kg) on days 0 and 2 (1M group); twointramuscular injections of saline (volume equivalent to florfenicol dosed at 20 mg/kg) ondays 0 and 2 (CTRL group). Calves that developed corneal perforations following day 0were removed from the study and treated with a single intramuscular injection ofoxytetracycline (20 mglkg). Treatment was considered successful and furtherobservations were discontinued if a corneal ulcer healed after day O. Failures weredesignated in cases of corneal perforation or ifthe ulcer was still present on day 20.

A Cox regression model of corneal ulcer healing time indicated that followingadjustment for initial corneal ulcer size, the corneal ulcer cure rate was 2.7 and 3.4 timesgreater in the SC and 1M groups, respectively, when compared to the control group.Corneal ulcer scores were significantly different between 1M and CTRL groups on days 4,6,8, and 14 and between SC and CTRL groups on days 6,8,10,12, and 14. Corneal ulcerscores did not differ significantly between the 1M and SC groups on any study day.Corneal surface area measurements (SAM) were significantly different between 1M vsCTRL and SC vs CTRL groups starting on day 4 and continuing throughout the study.The SAM did not differ between 1M vs SC groups. Clinical signs differed significantlybetween the 1M and SC groups vs CTRL group on days 2,4,6, and 8. Florfenicoladministered as either a single SC dose or as two 1M doses is effective against ffiK.

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Demonstration of Beef Cattle Marketing Alternatives

Larry Forero, Livestock/Natural Resource Farm Advisor, VCCE Shasta CountyGlenn A. Nader, Livestock! Natural Resource Farm Advisor, VCCE Sutter-Yuba County1. Michael Connor, Superintendent, DC Sierra Foothill Research & Extension Center

The cattle market has producers reviewing marketing alternatives. Selling cattle as calves,yearlings or retaining ownership through the feedlot are all options producers consider. Thisdemonstration uses cost and return numbers to discuss the benefits and liabilities of eachmarketing scenario.

Ten weaned steers were selected in May of 1996 and 1997. The cattle value is based upon theFriday sale in Cottonwood that week. The weight and value for cattle are estimated in Table A.

T bl A Wi· h d d 1a e elK! tan estimate va ue at weanmK.Year WeaningWt $/cwt (May) Avg $/hd

1996 469lbs $58 $272

1997 511lbs $79 $404

Cattle were summered at SFREC on irrigated pasture gaining 1.36 and 1.47 lbs/day in 1996 and1997. In late August five head were selected and shipped to McArthur. The weight and value forcattle are estimated in Table B.

Table B. WeiKht and estimated value 0 rcattle as yearlinKs.Year Yearling Wt $/cwt (Aug) Avg $/hd

1996 671lbs $60 $403

1997 729lbs $73.55 $536

The cattle were consigned to the InterMountain Fair Steer Futurity in August. The steers wereevaluated live as feeder cattle in McArthur and then shipped to a feedlot along with approximately100 head of steers owned by a variety of Northern California ranchers. Average daily gain wascalculated in the feedlot and animals were processed when finished. Payment for animals wasbased on rail value less feedlot expenses. Average feedlot performance and carcass data aresummarized in Table C.

Table C. Carcass andfeedlot attributes.Year Wt. In Wt. Out ADG Carc. wt. Fat Ribeye KPH Quality Yield Days fed

1996 671 1044 2.80 641 0.41 11.3 2.2 Se 2.78 134

1997 729 1154 3.38 721 .54 12.6 2 Ch- 2.96 128

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ConclusionOne of the goals of this demonstration was to look at three marketing opportunities for thesecattle and determine which afforded the "best" return for that set of cattle. Table D demonstratesthe value added to the cattle as a result of summering them on irrigated pasture on the FieldStation. Cost to summer the cattle was estimated at $.27/lbs gain and $5/headveterinary/medicine charges. No interest or opportunity cost was applied.

leatSFREC.hd 'h'00T bl D Ea e conomlc ta aSSOCiate Wit summermg t e cattYear Calf Value Yrl Value Cost Profit1996 $272 $403 $60 $711997 $404 $536 $64 $68

Table E demonstrates that holding the cattle over the summers of 1996 and 1997 netted back andaverage of$70 per head over selling the calves off the cow.

Holding the cattle past the stocker phase was a poor choice in 1996 and 1997. The high cost offeed associated with soft market conditions resulted in cattle losing an average of $124.50 perhead over their value as feeder cattle. Again, no opportunity cost was applied.

Table E. Economic data associated withfeedin 7

1996 1997

Gross Value $582 $757

Feedlot Costs $337 $312

Cattle Value $403 $536

Net <$158> <$91>

the cattle.

The 1996 and 1997 values earned is not reflective of the long term trend experienced by theInterMountain Fair Futurity. Figure 1 demonstrates the nine year average return over feedercattle value by participants.

Figure 1. Average per head return over cash costs experienced by IMF Futurity participants.

Because of the variability in results (demonstrated in Figure 1) the short term nature of thisdemonstration it cannot reflect long term trends. It does, however point to marketing windowsand potential marketing opportunities that require constant evaluation by producers.

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Supplemental Feeding of Beef Cows on Two Forage Levels

Mike Connor, Superintendent, DC Sierra Foothill Research & Extension CenterJames W. Oltjen, CE Management Systems Specialist, Animal Science Dept, DCD

Introduction

Previous research at Sierra Foothill Research and Extension Center has shown that feeding ofsupplements to beef cows increased calf weaning weights but was not economic (Morris, 1985).That research covered several years during which five levels ofalfalfa cubes, zero to 11 pounds perday, were fed during the late dry season and inadequate green feed period (late August to earlyMarch). Pregnancy rates were not significantly improved by supplementing in this study, and whileweaning weights increased in direct proportion to levels of supplement provided, the supplementcost $2.00 for each pound of increased calf weight.

These results were contrary to many recommendations and previous studies relating tosupplementation of beef cows. It is important to try to determine why Dr. Morris' results differedfrom accepted practices. Most of the previous California research took place at the San JoaquinExperiment Range in Madera County, where forage conditions often differ from those found here.Also, the question arises as to when during the year supplementation should occur. Perhaps theeconomics of supplemental feeding can be improved by reducing the total time of the feedingperiod.

The project Strategic Supplementation ofRange BeefCows reported on by Dr. Oltjen earlier todayis designed to address these questions. The purpose of this report is to further discuss the foragelevel (stocking rate) aspects of that study.

Procedures

Cows in this trial are maintained on two grazing intensity levels, moderate and heavy, during thecritical time of the year, from calving until adequate green feed. The cows leave their calvingfields the latter part ofOctober, and adequate green feed, and thus the end of the supplementperiod, occurs about March 1. During late October to March 1, cows in this study are rotatedamong three to four dryland pastures. This is done not so much as a designed rotation grazing plan,but to maintain desired differences in forage availability between the two grazing level groups.

Grazing intensity is often discussed in terms of stocking rate (acres per cow), but for this study it ismore accurate to describe the amount of forage available to the animals. In fact, the stocking ratewas similar on the average for both groups at about three acres per cow (although stocking wasmore intense at times for the heavy grazing group).

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Forage levels are estimated each time the cows enter or leave a field during the October to Marchperiod. We travel through the field estimating the size of locations that have substantially differentamounts offorage. For each general area ofdifferent forage levels, a series of one square foot areasare sampled. The samples are dried and weighed and the pounds ofavailable forage for the field iscalculated. The pastures range in size from 30 to 800 acres, usually 35 to 200 acres. In most cases,during late October to March 1, the grazing intensity is such that there is little difference in forageavailability within a given field.

Results

There was considerable difference among years in the amount offorage available, but the levelswere less for the high stocking rate cows than for the moderate stocking rate group during each yearof the study.

Forage Availability at Two Stocking Levels, pounds per acre

Moderate stocking

High stocking

1995-96

2120

1570

1996-97

1600

930

1997-98

700

580

Forage level affected the efficacy of supplementation treatments in this study as discussed earlier byDr. Oltjen. Pregnancy rate was not improved by supplementing the cows stocked at a moderatelevel. At the heavy stocking rate, strategic supplementation (supplementation to meet conditiontargets) increased the pregnancy rate by nine percentage units and standard supplementation(supplement fed from late August to March 1) increased pregnancy by 13 percentage units (to77.5%).

The effect of supplementation on calfweaning weights also varied with forage availability levels.Moderately stocked cows receiving no supplementation or the strategic treatment produced heaviercalves than did those under the heavy stocking regime. The difference was 13 or 21 pounds for theno supplement or strategic group, respectively. Stocking rates had no effect on the cows receivingthe standard supplement treatment.

The study should help to answer questions regarding the timing ofeconomic supplementation ofbeef cows and the interactions between forage levels and supplement effects.

Further Reading

Morris, James G. 1985. Evaluation offeeding value and costs of cattle supplements. Proc., Univ. ofCalif., Davis Dept. of Animal Science and Cooperative Extension BeefDay, Oct. 15-18, 1985. pp.7-13.

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GRAZING EFFECTS ON SPRING ECOSYSTEMS

Barbara Allen-Diaz, Associate ProfessorDept. ESPM - Ecosystem Sciences DivisionUniversity of California, Berkeley, CA 94720

OBJECTIVES

Examine cattle grazing effects on undeveloped, cold-water spring water quality,vegetation cover and composition, insect family richness, and channel morphology.

METHODS

Three spring-creek cohorts from each of3 watersheds (Campbell, Schubert, and Forbes)were located and randomly assigned one of3 grazing treatment levels. Mean annualresidual dry matter (RDM) levels were ungrazed (- 2500 kg/ha RDM), lightly grazed (­1500 kg/ha RDM), or moderately grazed (- 1000 kg/ha RDM). Permanent line-pointtransects were established parallel to spring-creek flow for vegetative cover and plantcommunity composition estimation. Permanent line-point transects were establishedperpendicular to spring-creek flow to measure annual channel morphology fluctuation.Insect emergence traps were placed at springheads during four seasonal periods in 1996 toassess insect family richness over time and grazing treatments. Water samples werecollected from spring-creek effluent post-livestock grazing to estimate nitrate,orthophosphate, dissolved oxygen, temperature, and pH.

RESULTS

Vegetation

Split-plot repeated measures ANOVA results indicated that total herbaceous cover variedsignificantly over time (year) but not grazing (Fig. 1). Temporal variation in total coverwas apparently associated with previous year rainfall. Plant community composition andstability over time and grazing treatments were analyzed with TWINSPAN (Two-wayIndicator Species Analysis), a polythetic, divisive classification computer application.With few exceptions, sites persisted as stable plant communities regardless ofgrazingintensity (Fig. 2).

Channel Morphology

Total change in cross-sectional channel depth was estimated annually. No significantgrazing treatment effects were detected (Fig. 3). Channels in ungrazed plots varied moreover time than those in grazed plots. Although there is clearly a trampling effect fromcattle on the morphology ofgrazed springs, our method did not demonstrate thisquantitatively.

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Insects

Aquatic insects are frequently studied to evaluate the ecological integrity of streams.Reduced community richness may indicate organic pollution and/or habitat degradation.Trapped insects were identified to family. Analysis was limited to families with aquaticgenera; wholly terrestrial families were excluded. Repeated measures ANOVA revealedthat moderately grazed spring sites exhibited reduced insect family richness compared toungrazed and lightly grazed sites (Fig. 4) and that insect family richness was significantlylower in February than July, September, and April sampling dates (Fig. 5).

Water Quality

Spring water was monitored to assess potential livestock effects on spring-creek sedimentand nutrient loading. No significant differences among grazing treatments were found forcumulative 5-year means ofnitrate, orthophosphate, dissolved O2, temperature, and pH(Table 1).

Table 1. Cumulative five-year (1992-96) water quality means and standard errors.

PARAMElER MG LG UG

Nitrate (mg/l) 1.17 (1.02) 1.78 (1.15) 1.92 (1.08)

Orthophosphate (mgll) 0.10 (0.05) 0.13 (0.08) 0.15 (0.09)

Dissolved O2 (mgll) 4.85 (1.62) 7.02 (1.96) 5.32 (1.90)

Temperature eC) 17.42 (4.29) 17.62 (3.75) 17.77 (3.43)

pH 6.85 (0.64) 6.81 (0.57) 6.79 (0.56)

ACKNOWLEDGMENTS

The Integrated Hardwood Range Management Program funded this research. Specialthanks to Mike Connor & staff (SFREC), James Bartolome, Irene Timossi, RandallJackson, Mark Spencer, Cheryl Lovato Niles, Chris Campbell, JeffFehmi, Clay Taylor,Eric Hammerling, Catherine Philips, Shelley Evans, Steve Rothert, Rohit Salve, and CraigAnderson (DC Berkeley).

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!;.;iw'PPTtot (em) -+-COVER (%)

140 80

120 70 1-30

S rtU PJ

---- 60 /--I

s:: 100 ::r::0 CD

.'-; 50 I"i4J trco 80 PJ4J ().'-; 40 CD, PI 0I\)

~ 0'-;60 ~, u (fl

Q) 30H ()Pol

•0

40 <:r-I 20 (1)co I"i4J0

20 +8 , I I I '>1 , I .. .... ·.·1 I ··Wiil..L 10 0\0

----o I F<'" .,....,. " <·:f:..'.:····' ., I ,........ ... "....,;' ............... ,'1 I ,::............... .,'.....,'...... "': ".,. "., I ' ......... ' ..........,.. :... ' I , ...... ..................... , I I ... ... " I 0

91/2 92/3 93/4 94/5 95/6 96/7

Rain Year (July-June)/Cover Sampling done in June

Figure 1. Annual precipitation and total herbaceous cover 1992-97.

~" l'f'+v~t~s ca ~ orn~ca-

+Brachypodium dis tachyon­+Cynosurus echinatus­

+Toxicodendron diversiloba­-Quercus wislizenii++Lolium multiflorum­

1..=0.370

I

NNI

Figure 2. TWINSPAN classification results (e.g. 92-97 denotesconsecutive years; FM=Forbes Moderately grazed; Sp=Spring & Cr=Creek;A=eigenvalue of a given split).

SPRINGS CREEKSs.e. ± 1.9 10 s.e. ± 1.7

S

1:0 ~ $()

$ $8

~ 6

$ $$4 "i 4

2 2UG LG MG UG LG MG

Grazing treatment Grazing treatment9 .... .' UG

l ",5. e. ± 1.1 9 5 . e . ± O. 8 .,.,, " .'8 ,. " .'.',. " .'I . " 8 ,

f\J - , . ~. .,'S 7 ,. . ,w u .,' T "1GI 7~ ,."'-'.... .'

~6 $ .···LO

.,.... ,.,6 ............ .s'-

5 ......4.6 ...... I 5.'

4 1.................. I 4

3 1..................

I92-93 93-94 94-95 95-96 92-93 93-94 94-95 95-96

Year Year

Figure 3. Total channel morphology change (T~) for springs andcreeks by grazing treatment and over time.

2.5

2.0U)U)(l) 1.5~

...c:I .~ 1.0

N.J::o ~I

0.5

0.0

UG LG

Grazing treatment

MG

Figure 4. Log transformed insect family richness by grazing treatment.

2.5

2.0U)U)ill 1.5~

r.c:I .~ 1.0

!'Jen p:;I

0.5

0.0

July Sept Feb April

Sampling month

Figure 5. Log transformed insect family richness by season

Panel DiscussionViewpoint of David Pratt and Roger Ingram, UC Farm Advisors

Controlled GrazingControlled grazing is a process of matching plant and animal requirements toachieve production and performance targets. Controlled grazing means control oftime animals graze a paddock and the time each paddock is allowed to recoverfrom grazing. It means control of stocking rate and paddock size. It also meansyou can control the amount of plant material left after grazing .

Controlled grazing can help livestock producers maximize the sustainableproduction of high quality forage and animal products from the land. It can bepracticed on irrigated pasture or dry rangeland.

To implement a successful controlled grazing system you must have a workingknowledge of pasture ecology. You must understand the relationships of time toplant growth and animal performance, and the relationship of stock density toforage quality. You must be able to assess the quantity and quality of forage inpastures before and after grazing.

Controlled grazing isn't right for everyone. Its success depends on welldeveloped goals and its implementation must be guided by through economicanalysis. Unlike many "add-on" technologies that are compatible with existingmanagement methods, implementation of controlled grazing may requirefundamental changes in a ranch business. It also requires flexibility. Managersmust monitor pastures and animal condition and make adjustments as conditionschange or results from practices deviate from plans.

If none of your cows got bred because your bulls were infertile, you'd betterspend your money on new, fertile bulls before you spend it on new fences. But ifthe weak link in your business is converting solar energy into forage, orconverting forage you already have into animal products then controlled grazingcan improve profitability.

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Grazing Management Strategies for Annual Range

James Bartolome, Professor, Rangeland EcologyDivision of Ecosystem SciencesUniversity of California, Berkeley

My discussion limits "Annual Range" to uplands dominated by annual plants introducedfrom the Mediterranean region. This range type has a long history of excellent research, which Iwill highlight with summaries of the most significant findings relevant to grazing management.

Work by the USFS at the San Joaquin Experimental Range in Madera County beginning inthe 1930's established that adaptations to predictable seasonal weather patterns (Hutchinson et al1944) and unpredictable annual climatic variability were the keys to successful livestockproduction (Bentley and Talbot 1951). Early on, researchers established that what they calledmoderate use was the key to soil protection, forage production, forage quality, and livestockperformance. Use was easily measured in the fall using photographic guides and ocular estimates,which were incorporated into USFS Region 5 Range Handbooks.

In the early 1950's research focused on methods for range improvement and refinement offorage and livestock management guidelines. Heady (1956) demonstrated experimentally at UC'sHopland Field Station in Mendocino County that the amount of mulch or residual dry matter(RDM) in the fall, subject to the overriding limitations ofweather, determined the amount andcomposition of forage. Heady also conducted considerable research into diet composition andgrazing management, concluding that specialized grazing systems had little value on annual range(Heady 1961).

Heady expanded his research on mulch and RDM statewide to nine sites in the 1960's and70's. The results (Bartolome, Stroud, and Heady 1980) confirmed that RDM was the key tomanaging production and composition on annual grassland with more than 12" annualprecipitation. That study showed that the grassland could be conveniently divided into threesubtypes-- Coastal Prairie, Annual Grassland, and Dry Annual Grassland-- each with differingresponse to seasonal and annual weather, species composition, and RDMrequirements/recommendations.

The results cited above, all based on solid experimentation, form the basis for modernlivestock management recommendations (George et a11996) for annual rangelands and associatedoak savannas and woodlands. The early recommendations for moderate use (Bentley and Talbot1951) are very close to the RDM levels subsequent research determined appropriate for mostannual range. Heady's conclusion (Heady 1961), that seasonal grazing systems have no provenbenefit, still holds and is supported by subsequent additional work (Bartolome and McClaran1992, Bartolome 1993). Major research gaps are in experimental support for specific savanna andwoodland understory RDM recommendations and a need for better understanding ofsite/soil/plant relationships.

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References:

Bartolome. lW., M.C. Stroud, and H.F. Heady. 1980. Influence of natural mulch on forageproduction at differing California annual range sites. l Range Manage. 33:4-8.

Bartolome, lW. and M.P. McClaran. 1992. Composition and productivity of California oaksavanna seasonally grazed by sheep. Journal ofRange Management 45:103-107.

Bartolome, J.W. 1993. Application ofherbivore optimization theory to rangelands of the westernUnited States. Ecological Applications 3(1): 27-29.

Bentley lR and M.W. Talbot 1951. Efficient use ofannual plants on cattle ranges in theCalifornia foothills. USDA Circ. 870. 52p.

George, M.R, W.E. Frost, N.K. McDougald, lM. Connor, lW. Bartolome, RB. Standiford, lMaas, R Timm. 1996. Livestock and grazing management. In: Standiford, RB. (tech. coord.)Guidelines for managing California's hardwood rangelands. University ofCalifornia, Division ofAgriculture and Natural Resources Publication 3368: 51-67.

Heady, HF. 1956. Changes in a California annual plant community induced by manipulation ofnatural mulch. Ecology 37:798-812.

Heady, H.F. 1961. Continuous versus specialized grazing systems. A review and application tothe California annual type. 1. Range Manage. 14: 182-193.

McDougald, N.K., W.1. Clawson, 1.W. Bartolome, and W.E. Frost. 1991. Estimating livestockgrazing capacity on California annual rangeland. D.C. Davis Range Science Report 29. 2p.

Talbot, M.W. and H.H. Biswell. 1942. The forage crop and its management. In: Hutchinson, C.B.and E.I. Kotok. The San Joaquin Experimental Range, pp. 13-49. Calif. Agr. Expt. Bull. 663.

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