Continued on page 2ONE - 2003LIGHTING PROGRAMS ANDCOBB 500 BROILER PERFORMANCELeonard W. Fussell D.V.M., M.A.M. Diplomate A.C.P.V., Aldo Rossi D.V.M., Matthew Wilson Broiler SpecialistSurveys of broiler lighting programs around the world reveala plethora of entrepreneurial lighting regimes.To discern whichbroiler lighting program should be implemented, there areseveral critical factors a producer should consider. This paperattempts to answer the following questions: What are thespecific benefits of such programs? Are breed differencesseen in their responses to broiler lightingprograms? How should the program beadjusted for open-sided curtain houses vs.solid sidewall housing? Should a lightingprogram be adjusted based on averagedaily gains? What are the animal welfarebenefits of broiler lighting programs?Canada and Europe have led much ofthe research effort in developing specificlighting programs, particularly in solidsidewall housing. This work done in solidsidewall housing has generally beenapplied to poultry operations in morenorthern latitudes. Meanwhile integrators inthe United States have, during remodelling orexpansion efforts, also migrated towards darkcurtain or solid sidewall housing. Clear curtainsidewall housing however, still remains inprevalent use throughout the US industry andmuch of the rest of the world. Broiler producerswith clear curtain or open sidewall housing arerestricted in lighting alternatives and are forced todesign programs around the limitations ofnatural daylight/length. To address the uniquedifferences of these two scenarios, this paperprovides examples of lighting programs for both opensidewall and solid sidewall housing.The benefits of broiler lighting programs on improvedperformance as measured by improved livability, average dailygain (ADG) and calorie conversion or feed conversion rate(FCR) are well documented.Lighting programs improve livability by decreasingmortalityasspelledoutinthefollowingpartial listof causes:a) Reduction in mortality due to ascites (water-belly) andsudden death (flip overs)Ascites has a complex etiology with contributing factors such asgenetics,temperature,altitudeandventilation.Anyconditionthatmay increase the oxygen demand at the tissue level or inverselydecrease the oxygen carrying capacity of the circulatorysystem can result in pulmonary hypertension andright heart failure with the clinical sign ofascites. (Julian, R.J. 1993) To counter this,primary broiler breeders have aggressivelyselected against ascites for over a decade.Ascites resistance has successfully beenselected for,while geneticists continue toimproveaveragedailygain(ADG).Toolsused at Cobb-Vantress in the selectionprocess against ascites include fullbroilerization and routine use of the“pulse oximeter”to measure blood oxygensaturation with results applied as a selectioncriterion. While genetic resistance has beenpartially successful, broiler management stillplays a role in avoiding ascites. Light restrictionprograms for broilers are established as havinga profound effect in ameliorating late mortalitydue to ascites.b) Reduction in mortality due to leg problems(Valgus/Varus deformities, Spondylolisthesis(kinky back),rotated tibia)Leg problems have been an important ongoingcriteria in genetic selection but problems canstill arise. It is well documented that lightingprograms can reduce the incidence of leg disorders inbroilers. (e.g. Buckland et al., 1973, 1974; Buckland, 1975;Classen and Riddell, 1989; Simons, 1982, 1986; Wilson et al.,1984; Simons and Haye, 1985; Ketelaars et al., 1986, Rendenet al., 1991, 1996). Research by Sorenson et al. (1999) seemedto refute earlier research on the benefits of moderatedphotoperiods for broilers during the first three weeks.However, broiler companies and other researchers extol thevirtues of lighting programs and the benefits for prevention
L I G H T I N G P R O G R A M S A N D C O B B 5 0 0 B R O I L E R P E R F O R M A N C E2Continued on page 3Continued from page 1of leg problems due to Valgus/Varus deformities (VVD) inparticular (Classon and Riddell, 1992). A Denmark study(Sanotra et al., 2002) demonstrated a significant reduction inthe prevalence of impaired walking ability (corresponding to(Bristol) gait score >2). In this study, broilers reared with alight-dark program were compared to broilers under constantlight. These researchers concluded that the light-dark programin this study not only reduced leg problems but also reducedchronic fear in the birds. Selection for ADG with concomitantselection for musculoskeletal integrity has been the practice ofCobb geneticists for many years. Selection for increasing ADGdoes not necessarily lead to development of musculoskeletalproblems. Genetic selection against musculoskeletal problemsand management interventions such as broiler lightingprograms and/or feed restriction programs offer a manageablesolution to welfare concerns in this important area.c) Reduction in spiking mortalityLighting programs have been shown to minimize the effects ofspiking mortality syndrome. Controlled amounts oflight/darkness can ameliorate much of the hypoglycemia,mortality and runting-stunting associated with spikingmortality syndrome of chickens. (Davis et al., 1996)d) Improved immunocompetenceThe light/dark period or diurnal rhythm of the typical broilerlighting program increases melatonin production. Melatonininfluences development of immunocompetency. (Moore andSiopes, 2000). Enhanced immunocompetency is a recognizedbenefit in broiler production.Cobb geneticists,Cobb veterinariansand consultants comprise the Cobb immuno-genetics committeewhose focus is the immunocompetence traits of Cobb breedingstock.Inadditiontoimmuno-geneticfactors,theaddedbenefitof alight/dark period on development of the immune system should notbe underestimated. The practice of offering additional lightstimulation in an effort to make up for a lack of genetic potentialin ADG may actually impair immunocompetence and negativelyimpact calorie conversion or FCR.A decision must be made as tothe appropriate lighting program considering all objectives.Benefits of Lighting ProgramsImprovements in ADG and FCR with broiler lightingprograms are well documented by research institutions and thepoultry industry. Increasing livability accounts for a portion ofimproved FCR. Any decrease in late mortality ameliorates theloss of feed calories by those birds that succumb. Likewise, wecan improve FCR and ADG by repartitioning the number ofcalories expended for bird activity to calories available for gain(Beker, A. et al., 2003). The caloric sparing effect of the restingresponse as influenced by a lighting program is evident incurrent research from Oklahoma State University with theCobb broiler. (Teeter, R. unpublished data). Moderate birdmovement or exercise is desirable for the benefit of legstrength. However, too much bird activity wastes calories andmay result in bird injury or downgrades evident at processing.This excess of activity can be controlled through lighting.AWord of CautionAverage Daily Gain (ADG) may be impaired with restrictivelighting programs under certain conditions. Growersexperiencing difficulty with average daily gains may not fare wellwith the longer dark periods. Careful observation of the factorsinvolved in performance are critical and upon study may requirecustomization of lighting programs to achieve desired benefits.In addition to genetics, the variables of feed nutrient densityand management factors have a significant impact on the resultsof any lighting regime. For any given feed nutrient density, feedintake is a critical factor influencing ADG and FCR. Whilelighting programs influence feed intake it must be noted that aslighting adjustments are made, feed availability (feeder heightadjustments,feed form,feeder management,etc.) becomes morecritical. In some parts of the world, growers practice purposefulfeed restriction to improve FCR and livability with good effect.However,accidental feed restriction is more common than manygrowers would admit and may result in frustrating impairmentsof performance or skin quality upon flock settlement.The BasicsLighting programs are typically designed with changesoccurring at predetermined ages and tend to vary according tofinal market weight of the broilers. A more refined programutilizing weekly average weight gain data is worthy ofconsideration.Itisrecommendedthatgrowershavescalesinplaceand consistently record weight data or average daily gain (ADG)information. However, most growers do not have accurate ADGinformation. The merit of gathering broiler weight data, at leastweekly is to allow educated adjustments of lighting programs anddetermine the factors that compromise ADG.At first this seems adauntingtaskbutthereareefficientandpracticalmeansof weightdata collection. Bucket (group) weighing may be used at youngages as a tool to make decisions on initial light restriction.Figure 1.is shown to accent the need to control growth duringthe 14-21 day period. Excessive growth during this period maybe detrimental to performance or mortality. Lighting programsare one tool to control growth during this period.400035003000250020001500100050000 10 20 30 40 50 60Cobb Standard Example 1 Example 2Good 7 day weightsessential. Excessive14-21 day growthcan be detrimentalto final weights.Figure 1
L I G H T I N G P R O G R A M S A N D C O B B 5 0 0 B R O I L E R P E R F O R M A N C E3Continued on page 4Continued from page 2When considering lighting programs as a management tool,both the amount of light and light intensity are factors that needto be considered when designing a successful program. Field dataindicates that a minimum light intensity of 20 lux (2 FC) helps tostimulate bird activity during the first 5-7 days. Properstimulation of activity during these first few days of life is neededto ensure that the chicks become properly acclimated to theirenvironment and is essential for optimal feed consumption.Recent evidence suggests that 60 lux (6 FC) offers additionalenhancement of early weight gains. At the onset of lightrestriction,lightintensitycanbedecreasedtobetween5and10lux(0.5-1.0 FC) for the balance of the grow out period incorporatinga light intensity increase just prior to processing (10 to 20 lux or 1to 2 FC). A general suggestion is to start light restriction at about160 grams of weight. As a rule chick weights typically quadrupleby 7 days of age. (Example: 40 gram chick x 4 = 160 grams.) Ifweights are less than expected,a one or two day delay in the onsetof lightrestrictionmayhelptoenhanceperformance. Conversely,light restriction should commence at an earlier day of age if chicksreach this 160 gram weight prior to 7 days.We recommend one block of darkness and that this darknessbe given at night even in solid sidewall houses. Keep the “offtime” the same for the entirety of the grow-out period. Feedingand drinking behaviour becomes established and moving the“off time” earlier will cause a significant decrease in feed andwater consumption. It is the“on time”that should change as theamount of light hours change.Examples below are for straight run (as hatched) weights andage and include examples for curtain-sided and solid sidewallor dark curtain conditions. Genetics, feed density, feed intakeand management programs significantly impact results andmust be considered when customizing the program. Thechallenge is to customize broiler lighting programs usingstrategic broiler weights to refine adjustments. The charts orexamples show minimal lux recommendations and are basedon the current average daily gains, not the desired ADG.Lighting Programs For Solid Side Wallor Dark Curtain Broiler Housing55+ Grams (0.12 lbs) Average Daily GainAge (days)* Wt. (gm) Light (hrs) Dark (hrs) Light Intensity (lux)Days Prior to Slaughter:**0 40 24 0 20-601 48 23 1 20-606-7 160 Natural + 2 5-1020-15 Natural + 4 5-1015-12 Natural + 6 5-1010-6 23 1 5-10Till Market 23 1 5-10 ---> increase***1 Lighting programs involving natural light will be variable in theirrestriction of light depending on the time of the year and the latitudeof the farm.2 Light intensity recommendations are with artificial lightonly at the outside feed line.50+/- Grams (0.11 lbs) Average Daily GainAge (days)* Wt. (gm) Light (hrs) Dark (hrs) Light Intensity (lux)Days Prior to Slaughter:**0 40 24 0 20-601 48 23 1 20-607-8 160 Natural + 4 5-1020-15 Natural + 6 5-1015-12 Natural + 8^ 5-1010-6 23 1 5-10Till Market 23 1 5-10 ---> increase***45+ Grams (0.10 lbs) Average Daily GainAge (days)* Wt. (gm) Light (hrs) Dark (hrs) Light Intensity (lux)Days Prior to Slaughter:0 40 24 0 20-601 48 23 1 20-608 160 Natural + 6 5-1015-12 Natural + 8^ 5-1010-6 23 5-10Till Market 23 1 5-10 ---> increase***55+ Grams (0.12 lbs) Average Daily GainAge (days)* Wt. (gm) Light (hrs) Dark (hrs) Light Intensity (lux)0 40 24 0 20-601 48 23 1 20-606-7 160 18 6 ---> 5-10**10-11 300 15 9 5-1013-15 450 12 12 5-1015 15 9 5-1012 18 6 5-109 21 3 5-106 23 1 5-10Till Market 23 1 5-10 ---> increase****Days Prior to Slaughter:***Lighting Programs forOpen Sided Broiler Housing* Age at which to make light change.** If thinning a flock, follow the program for the whole flock. Afterthe flock is thinned, revert back to Natural Day Length plus 6hours for the remaining birds. 6-7 days prior to kill of theremaining flock, increase light to 23 hours light:1 hour darkness.*** 24-48 hours prior to catch, increase light intensity an additional5 to 10 lux (0.5 to 1FC) to acclimate birds for catch.^ Depending on the time of the year and the latitude of thefarm, this additional 8 hours of light may equal 24 hoursof continuous light; however adjust added light amountso that there is a minimum of 1 hour of darkness.50+/- Grams (0.11 lbs) Average Daily GainAge (days)* Wt. (gm) Light (hrs) Dark (hrs) Light Intensity (lux)0 40 24 0 20-601 48 23 1 20-607-8 160 18 6 ---> 5-10**11-12 300 15 9 5-1015-12 18 6 5-1012 20 4 5-109 21 3 5-106 23 1 5-10Till Market 23 1 5-10 ---> increase****Days Prior to Slaughter:***
L I G H T I N G P R O G R A M S A N D C O B B 5 0 0 B R O I L E R P E R F O R M A N C EContinued from page 3Lighting programs employed around the world are notstandardized and likely will never be. However, when oneconsiders all of the variables involved in the rearing of broilersand the individualistic objectives of poultry companies, this isno surprise. Weight, feed intake and mortality data are neededto customize the lighting programs of the future.Research and the popular use of broiler lighting programsprovide data and an endorsement of efficacy. Broiler lightingprograms in concert with the proper genetics, environment,nutrition and management create the best in welfare for theanimal and performance for the integrator.45+ Grams (0.10 lbs) Average Daily GainAge (days)* Wt. (gm) Light (hrs) Dark (hrs) Light Intensity (lux)Days Prior to Slaughter:0 40 24 0 20-601 48 23 1 20-608 160 18 6 ---> 5-10**12-9 20 4 5-109 21 3 5-106 23 1 5-10Till Market 23 1 5-10 ---> increase****COBB-VANTRESS, INC.PO BOX 1030, SILOAM SPRINGS,ARKANSAS 72761, USATEL: +1 479 524 3166FAX: +1 479 524 3043EMAIL: firstname.lastname@example.orgCOBB EUROPEMIDDEN ENGWEG 13, 3882 TSPUTTEN, THE NETHERLANDSTEL: +31 341 36 08 80FAX: +31 341 36 05 24EMAIL: email@example.comCOBB-VANTRESS BRASIL, LTDA.RODOVIA ASSIS CHATEAUBRIAND, KM 10CEP: 15110-000/CAIXA POSTAL 2,GUAPIAÇU-SP-BRASILTEL: +55 (17) 3267 9999FAX: +55 (17) 3267 9992EMAIL: firstname.lastname@example.orgWEBSITE: www.cobb-vantress.comReferences:Beker,A.,Vanhooser,S.L.andTeeter,R.G.,(2003)Lightingeffectsonbroilerfeedconversionand metabolic factors associated with energetic efficiency. Oklahoma State University andCobb–Vantress Cooperative Research Project.Buckland, R.B. (1975) The effect of intermittent lighting programs on the production ofmarket chickens and turkeys.Poult.Sci.J.,31 262-270.Buckland, R. B., Hill, A.T. and Bernon. D.E. (1973) Effects of four lighting regimes on theperformance of broilers and roasters.Can.AJ.Anim.Sci.,53,21-24.Buckland,R.B.,Supeene,N.J.andBernon,D.E.,(1974)Comparisonof intermittentlightingprogrammesforproducingbothbroilerandheavyturkeys.IN:Proc.XVW.Poult.Cong.Pp.425-427.WPSA,New Orleans,LA.Classen, H.L and Riddell, C. (1989) Photoperiodic effects on performance and legabnormalities in broiler chickens.Poult.Sci.,68,873-879.Davis, J.F., et al. (1996) Experimental reproduction of severe hypoglycemia and SpikingMortality Syndrome using field-derived and embryo-passage preparations. Avian Diseases40:158-172.Julian,R.J.(1993)Ascites in poultry.Avian Path.22:419-454.Ketelaars,E.Hl,Verbrugge,M.,Van der Hel,M.,Van de Linden,J.M.andVerstegen,W.M.A.(1986) Effect of intermittent lighting on performance and energy metabolism of broilers.Poult.Sci.,65,2208-2213.Renden, J.A., Bilgili, S.F., Lien. R.J. and Kincaid, S.A. (1991) Live performance and yields ofbroilers provided various lighting schedules.Poult.Sci.,70,2055-2062.Renden, J.A., Moran, E.T. Jr. and Kincaid, S.A. (1996) Lighting programs for broilers thatreduce leg problems without the loss of performance and yield.Poult.Sci.,75,1345A 1350.Simons,P.C.M.(1982)Effectof lightingregimesontwistedlegs,feedconversionandgrowthof broiler chickens.Poult.Sci.,61,1546 (Abst.).Simons, P.C.M. (1986) The incidence of leg problems in broilers as influenced bymanagement.In:Proc.7th Europ.Poult.Conf.,Paris,pp 289-299.Simons,P.C.M.andHaye,U.(1985)Intermittentlightinghasapositiveeffectontwistedleg.MissetWorld Poultry,March 34-37.From Ireland, Matthew Wilson professionalfoundation was built from a comprehensivebackground in poultry production. Originatingfrom production management, Matthew hasprogressed from a technical advisory positioninto technical services. Currently Matthewholds the position of World Technical SupportBroiler Specialist for Cobb Vantress, Inc.With unflagging dedication, Matthew assistscustomers worldwide, helping producersto achieve the genetic potential ofCobb products.* Age at which to make light change.** Gradual dimming of light to 5 to 10 lux (0.5 to 1FC). Ifbirds are brooded in partial house, wait until birds are infull house to begin dimming light.*** If thinning a flock, follow the program for the whole flock.After the flock is thinned, revert back to 18 hours light: 6hours dark for the remaining birds. 6-7 days prior to killof the remaining flock, increase light to 23 hours light:1 hour darkness.**** 24-48 hours prior to catch, increase light intensity anadditional 5 to 10 lux (0.5 to 1FC) to acclimate birdsfor catch.The Cobb commitment to genetic improvement of the Cobb 500 continues to increase theperformance potential in all areas of broiler and broiler breeder production. However, to attain bothgenetic potential and consistent flock production, it is important that the flock manager has a goodmanagement program in place. The success of the Cobb 500 broiler worldwide has providedconsiderable experience of the breed in a wide range of situations: hot and cold climates, controlledenvironment and open housing. This Cobb 500 Broiler Lighting Guide is designed to assist you inbuilding your management program.Management must not only meet the basic needs of the stock but must also be finely tuned to benefitfully from the breeds potential. Some of the guidelines may need to be adapted locally according toyour own experience, and our technical teams will assist with this.The Cobb Breeder Management guides highlight critical factors that are most likely to influence flockperformance. Our recommendations are based on current scientific knowledge and practicalexperience around the world. You should be aware of local legislation, which may influence themanagement practice that you choose to adopt.The Cobb 500 Broiler Lighting Guide is intended as a reference and supplement to your own flockmanagement skills so that you can apply your knowledge and judgment to obtain consistently goodresults with the Cobb 500.