Commercial Broiler Production Research Articles

Vertical and Horizontal Transmission ofSalmonellaWithin Integrated Broiler Production System

Salmonella remains one of the leading causes of food-borne illness in the United States, and many key questions regarding the introduction and persistence in animal production systems still remain. In order to understand the ecology of Salmonella within an integrated commercial broiler production system, 289 Salmonella enterica were recovered from two integrated poultry farms during the production and processing of seven consecutive flocks. The variety and prevalence of Salmonella serotypes differed between farms. Overall, 15 serotypes were identified, with the most common being Typhimurium (55%), Montevideo (7.9%), Kentucky (9%), and Enteritidis (9.7%). Salmonella Typhimurium and Enteritidis isolates recovered from processed carcasses from Farm One were further characterized using pulsed-field gel electrophoresis (PFGE), and were shown to be indistinguishable from isolates recovered from the poultry house environment and mice trapped on this farm. Additionally, the same broiler S. Typhimurium and S. Enteritidis strains, identified by PFGE, were also isolated from samples taken at a company breeder farm, suggesting vertical transmission of these Salmonella serotypes in this poultry production system. Results indicate that management practices at the breeder level may have a profound effect on the transmission and persistence of salmonellae within an integrated production system, as well as on the potential contamination of poultry-derived products.

Welfare of Male and Female Broiler Chickens in Relation to Stocking Density, as Indicated by Performance, Health and Behaviour

AbstractThe purpose of this experiment was to provide information relevant to the current debate concerning the optimisation of terminal stocking density for commercial broiler production. In a modern, controlled-environment house with 24 floor pens (each 11.4 m2), 4020 day-old broilers (Ross 308) were allocated to three terminal (42 days) stocking densities (28, 34 and 40 kg m-2) x two sexes x four replicates, according to a randomised block design. Group sizes varied from 130 to 208. Husbandry conditions were in accordance with normal commercial practice. Performance and behaviour were measured systematically during each of the six weeks of life, and additional measurements were made of leg health and litter condition. Data were analysed using ANOVA to determine the effects of stocking density, sex and age. The realised mean terminal stocking densities were 28.2, 33.5 and 38.5 kg m2. The main significant effects of stocking density treatment were a linear decline in food intake with increasing density during week six (the final week), and a reduced proportion of time spent panting deeply during weeks five and six at the lowest density. Increased (shallow and deep) panting shown by females in weeks two to five suggests that if thermal discomfort becomes a problem at higher stocking densities later in the growing period, it may do so earlier in females. There was no conclusive evidence from this study that broiler welfare is compromised any more at 40 than at 34 kg m−2. The fact that the proportion of time spent panting deeply in week six was considerably lower at 28 kg m2 than at 34 and 40 kg m−2 suggests that thermal comfort (and hence welfare) at this age may be improved at densities of less than 34 kg m−2. However, the significant effects of age, age x density, and age x sex on time spent panting deeply suggest that the age at slaughter and the sex of birds in single-sex flocks should be taken into account in future considerations of optimal maximum terminal stocking density.

Estimation of Crossbreeding Parameters for Serum Lysozyme Level in Broiler

The main objective of the present study is to estimate the crossbreeding parameters in respect to serum lysozyme level in broilers. The experiment involved a complete 4×4 diallel design using four synthetic broiler lines namely Coloured Synthetic Male Line (CSML), White Synthetic Male Line (WSML), Coloured Synthetic Female Line (CSFL) and Naked Neck Line (NNL). The lyophilised Micrococcus lysodeikticus suspension was used to detect the lysozyme level in the serum of birds. The data were analysed by least-squares method to find the effects of genetic and non-genetic factors using appropriate model. The crossbreeding parameters for this trait were estimated by complete diallel model assuming the effect of each synthetic line as fixed. The results indicated that additive and non-additive genetic variation attributed to minor genes at many loci is important for the genetic control of serum lysozyme level in chickens. Total non-additive components of variance also showed significant amount of heterosis in crossbred progenies, and therefore exploitation of non-additive component of variance is possible for improvement in serum lysozyme level in broilers. The overall results suggested that for commercial broiler production system, the selection for specialised line on the basis of serum lysozyme level and subsequent crossing of parent lines could enhance the immunocompetence status in relation to serum lysozyme level in crossbred chickens. (Asian-Aust. J. Anim. Sci. 2002. Vol 15, No. 2 : 166-171)

An update on the epidemiology of contact dermatitis in commercial broilers

A computerized management and disease information retrieval system for commercial broiler production was established in 1985. The database presently contains information on over 950 flocks (15 million birds) per annum. The system has enabled the effectiveness of strategies which have been implemented to control contact dermatitis to be monitored. Between 1986 and 1994, the prevalence of breast burn lesions has been practically eradicated (0.2 to 0.00%) and the prevalence of hock burn lesions has been dramatically reduced from 21 to 7%. This reduction has been mainly due to the use of better litter management techniques and improvements in house design, particularly changing the type of drinker system. Production factors during 1993 and 1994 which were found to be consistently related to increased prevalence of hock burn lesions were male only flocks, inferior food conversion ratio, failure to meet target income and increased mortality rates.

Comparative efficacy of anticoccidials under the conditions of commercial broiler production and in battery trials

Coccidia were isolated from a commercial broiler farm with a history of suspected drug resistance. The sensitivity profiles of the Eimeria spp. isolates against the anticoccidial drugs nicarbazin (NIC), narasin (NAR), halofuginone (HAL), salinomycin (SAL), meticlorpindol plus methylbenzoquate (MET), and monensin (MON) at the recommended dose levels were followed in three battery trials (B1, B2, B3) corresponding to a field study over three periods of commercial broiler keeping (F1, F2, F3). Shuttle programs were performed in F1 (NIC/MON) and in F2 (MET/MON) while only SAL was used in F3. Eimeria acervulina and E. tenella were isolated from indicator birds in F1 while only E. acervulina could be found during F2 and F3. In trial B1 the isolate from F1 was identified as resistant against HAL and partly resistant against NIC and MON, the two drugs that were used in F1. Following the replacement of NIC in the starter feed by MET the respective isolate from F2 showed no resistance against ionophores (trial B2) while partial resistance against HAL was still present. Since SAL was the most efficient drug in B1 and B2 only this drug was applied in F3. Apart from a resistance against HAL no resistance against any of the other tested anticoccidials was found in the isolate from F3. SAL controlled coccidiosis efficiently in the field and best productivity was recorded in F3. This study shows that battery trials have a good predictive value in respect to the efficacy of anticoccidials under the conditions of commercial broiler production.

Sequential feeding of whole wheat to growing broiler chickens

1. Four broiler feeding trials were performed to examine the suitability of a whole wheat sequential feeding regimen for commercial broiler production. The sequential feeding programme gave a continuous cycle of ad libitum access to only whole wheat followed by the same time of access to only a pelleted diet. The pelleted diet provided a concentration of nutrients to balance that provided by the whole wheat. This was called a balancer diet. 2. The first trial used 144 cage-reared broilers from 28 to 49 d of age. Four different times of access (4, 8, 12 and 24 h) to the two alternate foods were compared. A whole wheat choice-feeding treatment and a complete single diet treatment were also compared. Whole wheat accounted for over 40% of the broilers' total food intakes when they were given the sequential feeding treatments of 8 h or greater. The whole wheat intakes of the birds given the 4 h sequential feeding and the choice-feeding were only 20 and 5% respectively. There was a non linear relationship between the weight gains of the broilers and the length of the sequential feeding period (P < 0.01). The growth rates of the broilers given sequential feeding were lowest (P < 0.05) in the 4-h feeding periods but highest (P < 0.05) in the 8-h periods. Weight gains decreased (P < 0.01) linearly as the sequential feeding periods were increased above 8 h. 3. A second trial, using 144 cage-reared broilers, examined the effect of different balancer compositions or different wheat varieties in 8-h sequential feeding. The broilers selected more whole wheat in their diet when they were given balancers with increased cereal contents. However, these broilers did not eat enough whole wheat to compensate for the reduced cereal content of the balancers and their overall diets had lower energy:protein ratios. The two different wheat samples did not result in any differences (P > 0.05) in the proportion of whole wheat selected by the broilers. 4. A third trial compared the diet selections, weight gains, food intakes and water excretions of 72 cage-reared broilers given whole wheat feeding regimens. The growth rates of the broilers given a loose mix of whole wheat and a pelleted balancer diet were similar (P > 0.05) to broilers given a complete single diet. The growth rates of these two groups were 7% greater (P < 0.05) than broilers given choice-feeding or 8-h sequential feeding.(ABSTRACT TRUNCATED AT 400 WORDS)

Economic effects of increased vitamin E supplementation of broiler diets on commercial broiler production

Abstract 1. The economic effects of increased vitamin E supplementation in 168 commercial broiler flocks incorporating over 3 million birds was assessed using a computerised data retrieval system. 2. Approximately half of the flocks were fed on either a high (163 mg/kg) vitamin E or on a normal (44 mg/kg) vitamin E‐containing diet throughout production. 3. Approximately half of the flocks were the progeny of breeder flocks which had been fed on a high vitamin E‐containing diet throughout production. 4. The improvement in target income in the vitamin E‐supplemented broiler flocks was 8–44% (P < 0.01). 5. The residual improvement in target income in these flocks, after the cost of the additional vitamin E was taken into account, was 2.74% and failed to reach statistical significance. 6. The increased net income was achieved by a significantly improved food conversion ratio and average weight per bird (P < 0.05). 7. There was no overall effect of vitamin E supplementation of broiler breeders on subsequent broiler performance.

Research Note: The Effects of Darkling Beetles on Broiler Performance

Six polyvinylchlorine pipe darkling beetle traps were placed in 20 commercial broiler production facilities, and the relative level of beetle infestation was determined from weekly sampling during 4 wk of the growout period. The average number of beetles found at each facility was compared with the following production parameters: mortality, feed conversion, condemnation rate, and production cost. In the 20 commercial broiler flocks evaluated, the level of darkling beetles within the facility was not related to any of the production parameters measured.

Anticoccidial Efficacy of Narasin in Floor Pen Trials

Narasin is effective against all species of chicken coccidia when tested in short-term battery cage experiments. The efficacy of narasin at concentrations of 20, 40, 60, 80, and 100 ppm was evaluated in ten floor pen trials in which commercial broiler production conditions were simulated. To provide intentional exposure to different levels of coccidia challenge, the litter of some pens was seeded with oocysts of each of the pathogenic species of chicken coccidia, whereas some pens were left nonseeded. Weight gain, feed efficiency, and lesion score data from the ten trials were analyzed as one randomized block experiment.Medication with narasin resulted in a significant reduction in lesion scores and significant improvement in weight gain and feed:gain ratios when compared with scores and gain of nonmedicated controls for both seeded and nonseeded pens. Each increase in narasin concentration up to 100 ppm for the seeded pens and up to 80 ppm for the nonseeded pens resulted in a significant reduction in cecal lesion scores. Although maximum weight gain in the seeded pens was obtained with 40 ppm narasin, concentrations ≥60 ppm narasin were significantly better than the 40 ppm concentration in improving feed:gain ratios.These results confirm the effectiveness of narasin in controlling coccidiosis in broilers exposed to oocysts in the litter of floor pens. Furthermore, a clear relationship between the response to narasin and the level of oocyst challenge was demonstrated.

Field Experience Trials Comparing Narasin and Monensin

Narasin is effective against all species of chicken coccidia when tested in battery cage and floor pen studies. To confirm the efficacy of narasin under practical broiler production conditions, the drug was fed at concentrations of 60 ppm or 80 ppm to broiler chickens being raised by six different commercial broiler producers in five different geographic areas. Monensin was fed in each trial at a concentration of 100 ppm or 121 ppm as a reference control. The usual management practices of each of the integrated broiler companies were followed throughout the respective trials. Nine trials were conducted and approximately 100,000 broilers were tested for each treatment.No adverse reactions attributable to treatments were observed in any of the trials, and performance results obtained with narasin-medicated birds were generally comparable with those obtained with monensin-medicated birds in the same trial. These findings support the conclusion that narasin at final feed concentrations in the range of 60 to 80 ppm can be safely and effectively used as an anticoccidial agent in commercial broiler production facilities.

Development of the Relative Economic Weights for Linear and Quadratic Bioeconomic Objectives in Commercial Broilers

The approach of Harris (1970) and Harris et al. (1984) was used to develop mathematical profit functions for describing the bioeconomic objectives in an integrated three-way cross commercial broiler production system. The reproductive and productive performances of the pureline maternal grandparent female and the single cross female parent were included to reflect the impact of the traits expressed in those populations. The resulting complex function was approximated with linear and quadratic equations. Inputs (costs) in the system included feed, housing, labor and facilities, and processing. Outputs (returns) included salvage value of the cull hens and the processed cut-up broilers. A systematic procedure was developed to calculate relative economic values of the traits in the breeding objective from the bioeconomic function. The traits were boiler livability, boiler weight, proportion of carcass, proportion of breast-thigh-leg, broiler feed consumption, grower livability, layer livability, rate of lay, settability, fertility, and hatchability. The relative economic values thus obtained were 1.51, 1.00, 5.99, 3.21, —.20, 0, 0, 0, 0, 0, and 0 in paternal grandparent; 4.48, 1.00, 5.99, 3.21, —.20, 3.00, 3.10, 4.58, 2.97, 3.04 and 3.04 in maternal great-grandparent male; and 9.30, 1.00, 5.99, 3.21, —.20, 7.88, 8.15, 12.06, 7.80, 7.97, and 7.97 in maternal great-grandparent female, for the traits in the above order.

Campylobacter jejuni in broilers: the role of vertical transmission.

The role of broiler eggs in the transmission of Campylobacter jejuni to broiler grow-out flocks was investigated. Six breeder flocks supplying broiler eggs to hatcheries were examined for cloacal carriage of C. jejuni. Of 240 birds tested, 178 (74%) were C. jejuni-positive. Eggs from these birds examined for C. jejuni penetration of the egg shell indicated that 185 of 187 were campylobacter-free. Eggs from breeder flocks of unknown C. jejuni status were also examined for C. jejuni shell penetration. C. jejuni was not isolated from 142 eggs examined. A further 193 hatchery eggs incubated and hatched in the laboratory were campylobacter-free. Six farms containing the progeny of C. jejuni-positive breeder flocks were monitored. Eight hundred and forty birds from 14 flocks in these grow-out farms were campylobacter-free during their 6-week grow-out period. Experimental egg-penetration studies indicated that C. jejuni transmission via the egg is not easily effected. Of 257 eggs surface-challenged with C. jejuni, 162 hatched; all were campylobacter-free. Of 167 eggs injected with C. jejuni, 12 hatched; 2 of these were colonized with C. jejuni. Our data do not support a role for vertical transmission of C. jejuni in commercial broiler production.

Economic Evaluation of Controlled Environmental and Conventional Contract Broiler Housing Systems in Georgia

The primary objectives of this study were to determine physical and economic differences among contract broiler housing systems as presently operated in Georgia. Production records for 1800 flocks of broilers were obtained from 15 integrated broiler production companies. Financial and labor records of 100 contract growers were obtained by personal interview surveys. The production data and costs and returns analysis indicated that the automatic curtain house may offer the best compromise for the contractor and the contract producer of all systems studied for commercial broiler production in the Southeast. These conclusions are based on the following advantages of the automatic curtain house system: production results from the automatic curtain house showed the 1) lowest mortality rate (3.04%) of all systems and some improvement over the conventional curtain house in feed conversion (2.12 pounds), 2) best returns to land, labor, and management for the contract producers of all systems studied, 3) simplest of all systems to operate, 4) lowest risk from disaster losses due to electric power failure and sudden change in temperature, and 5) lowest cost for brooder fuel and electricity of all systems studied except the conventional curtain system.

Effects of Monensin-Feeding Regimens on Flock Immunity to Coccidiosis

Feed medication with monensin caused delays in development of immunity in two floor-pen experiments which simulated commercial broiler production. Development of immunity was retarded with the higher level of monensin (120 p.p.m.) but was progressively less delayed as the monensin level was decreased (100, 60 or 0 p.p.m.). Delay was greatest with Eimeria tenella, but also occured with intestinal species including E. acervulina, E. brunetti, E. maxima, E. mivati, and E. necatrix. Drug withdrawal permitted earlier development of immunity. Plans involving use of monensin on layer replacements which later will be maintained on the floor without medication should consider: 1) prevalence of infective oocyst exposure in the area, 2) the lowest possible level of drug required for protection, and 3) its use for the shortest possible period of time.

The Influence of Feed Texture on Broiler Performance

Three broiler feeding experiments involving a total of 15,750 broilers were conducted to compare the effects of feed texture especially unsifted versus sifted pellets on broiler performance (weight and feed efficiency). Broiler chicks fed crumbles through the first four weeks of age were significantly heavier and required significantly less feed to produce a unit of body weight than those fed the all-mash diet. From 4 to 8 weeks of age the birds started on crumbles were fed: 1) pellets unsifted, 2) pellets sifted, 3) crumbles, and 4) one-half pellets and one-half crumbles. A detailed comparison between the broilers fed unsifted and sifted pellets revealed that their performances were almost identical. Therefore, the use of unsifted pellets would appear to be more economical for commercial broiler production than the more costly sifted pellets.

Studies on Trichloroethylene-Extracted Feeds: 8. The Relative Resistance of Avian Species to the Toxic Factor in Trichloroethylene-Extracted Soybean Oil Meal ,

A CONSIDERABLE proportion of the soybean oil meal produced in the United States is used for feeding chickens and turkeys. If these species were highly susceptible to the factor present in certain specimens of trichloroethylene-extracted soybean oil meal (TCESOM) which induces aplastic anemia in the bovine (Stockman, 1916; Pritchard et al., 1952; Picken et al., 1952) and the horse (Pritchard et al., 1956), it would be expected that toxic effects would have been observed among commercial flocks of chickens and turkeys. Such effects have not been reported although it is known (Armstrong, 1952), for instance, that the total output of TCESOM of one extraction plant which produced specimens of TCESOM which are highly toxic to the bovine (Schultze et al., 1955) was used for commercial broiler and turkey production without apparent untoward effects. Eveleth and Goldsby (1953), however, observed an increased mortality among baby chicks fed for 50 days a …

“performance index” of growing chickens

In commercial broiler production and in research on growth of chickens, it is common practice to compare groups with respect to weight and with respect to feed efficiency which is defined as the gain per unit of feed consumed. It often happens that groups are arranged in one sequence when compared on the basis of mean live weight and in an entirely different sequence when compared on the basis of efficiency. It then becomes desirable to make an over-all comparison that takes account of both weight and efficiency. Very frequently this is accomplished by multiplying mean live weight by efficiency or dividing mean live weight by feed conversion which is the reciprocal of efficiency. The resulting figure, designated the “performance index,” “efficiency index,” or “performance efficiency” has been used both by commercial broiler producers and by research workers (Lanson and Smyth, 1955; Wilder et al., 1955).Wilder et al., after …

Debeaking in Commercial Broiler Production

IN THE South Texas broiler area, one of the main problems confronting the broiler producer is poor feathering. This is especially so during the hot summer months when temperatures of 110° are not uncommon.Debeaking as a means of controlling feather picking and cannibalism was reported by Quisenberry and Draper (1946). Bice (1946) described some of the electrical debeakers then in use and how and when to use them. Debeaking has been recommended by the U.S. Department of Agriculture (1948) and has been practiced for several years in Hawaii and the desert areas of Southern California. Darrow and Stotts (1954) reported that debeaking did not appear to affect average weight or mortality; feed per pound of gain was reduced 0.1 lb.; and feather score and market grade were markedly improved. However, Darrow and Stotts debeaked their birds by removing ⅓ to ½ of only the upper beak at one day …

A Hemorrhagic Condition in Chicks Fed Simplified Rations

SIMPLIFIED rations have been used successfully by many workers in broiler chick nutrition studies. In the course of an investigation with such rations at this Station, a considerable mortality in the experimental birds was attributed to a hemorrhagic condition. This condition resembled the avitaminosis K syndrome described by Dam (1935) and by Almquist and Stokstad (1935 a, b). Since rations similar to those employed in this work are commonly used by other investigators and in commercial broiler production, an evaluation of this hemorrhagic condition seemed advisable. EXPERIMENTALNew Hampshire chicks hatched from the University flock were used in these experiments. The layers were maintained on deep litter and received a standard laying ration which contained 3 percent alfalfa meal. According to the work of Cravens et al. (1941) this level of alfalfa meal in the laying flock ration should provide an adequate intake of vitamin K.When the chicks were …

Use of Synthesized Models to Determine Broiler Processing Plant Economies

INTRODUCTIONTHE consumer demand for fresh, ready-to-cook broilers has expanded rapidly during the past decade. Washington commercial broiler production (2¼ to 4 pounds live weight) in 1940 totaled 2,148,000 pounds compared with a total of 17,580,000 pounds in 1950. This type of relationship also exists for other leading poultry-meat producing areas in the United States. This rapid expansion in Washington production has followed a similar expansion in the state’s urban population. This relationship is important, because an increasing production of fresh cut-up broilers must be accompanied by a market willing to purchase this increased production at a market price satisfactory to producers and marketers. Here it should be noted that although we are concerned primarily with broiler production and processing plants in Washington, these technical and economic relationships ought to apply to other areas.PROBLEM AND OBJECTIVESDuring the past decade, existing broiler processing facilities in Washington were inadequate to .