The Journal of Applied Poultry Research

Published by Oxford University Press (OUP)
Online ISSN: 1537-0437
Print ISSN: 1056-6171
Publications
Several mathematical or statistical and artificial intelligence models were developed to compare egg production forecasts in commercial layers. Initial data for these models were collected from a comparative layer trial on commercial strains conducted at the Poultry Research Farms, Auburn University. Simulated data were produced to represent new scenarios by using means and SD of egg production of the 22 commercial strains. From the simulated data, random examples were generated for neural network training and testing for the weekly egg production prediction from wk 22 to 36. Three neural network architectures-back-propagation-3, Ward-5, and the general regression neural network-were compared for their efficiency to forecast egg production, along with other traditional models. The general regression neural network gave the best-fitting line, which almost overlapped with the commercial egg production data, with an R(2) of 0.71. The general regression neural network-predicted curve was compared with original egg production data, the average curves of white-shelled and brown-shelled strains, linear regression predictions, and the Gompertz nonlinear model. The general regression neural network was superior in all these comparisons and may be the model of choice if the initial overprediction is managed efficiently. In general, neural network models are efficient, are easy to use, require fewer data, and are practical under farm management conditions to forecast egg production.
 
Broiler growth curve using the empirical data of Roush et al. [8]. 
Comparative broiler BW prediction using various neural network models. BP-3 NN = BackPropagation-3 neural network model (3 layers of back propagation, with each layer connected to the previous layer); BP-5 NN = BackPropagation-5 neural network model (5 layers of back propagation, with each layer connected to the previous layer); Ward-5 NN = Ward-5 neural network model (5 hidden slabs with various activation functions). 
Comparative guinea fowl BW prediction using various mathematical and neural network models. BP-3 NN = BackPropagation-3 neural network model (3 layers of back propagation, with each layer connected to the previous layer); Ward-5 NN = Ward-5 neural network model (5 hidden slabs with various activation functions); GR NN = general regression neural network model. 
Poultry growth is usually modeled with the Gompertz model or another nonlinear statistical model using average BW data over certain periods of time for a given strain of birds under specific farm management conditions. Constant selection in the genetic pool, nutritional factors, and environmental concerns, however, make such models limited in their utility because of the difficulty of fitting the growth curve across time, bird strains, and other determining variables. Moreover, generating data for every strain of birds under continually changing variables is difficult, expensive, and time consuming. The current model addresses 2 objectives: to simulate data using published literature for different growth periods, and to develop artificial intelligence models with various neural network architectures. By breaking down the actual broiler growth data into 5-d intervals, with known means and SD, normal distributions were generated for broiler growth using @Risk software. These simulated data were then used to recognize data patterns and model growth curves by using various neural networks. Three neural networks, namely, BackPropagation-3 (3 layers of back propagation, with each layer connected to the previous layer), BackPropagation-5 (5 layers of back propagation, with each layer connected to the previous layer), and Ward-5 (5 hidden slabs with various activation functions, using NeuroShell 2 Ward software) were used in this research. Once the networks were sufficiently trained, they were exposed to actual growth data to predict broiler growth over the next 50 d. The Back-Propagation-3 neural network gave the best fitting line, with predictions fitting tightly to the actual data points. The R(2) was 0.998, and nearly perfect. The R(2) for the BackPropagation-5 and Ward-5 neural networks were 0.967 and 0.973, respectively. To test the approach further, the same methodology was applied in guinea fowl growth prediction, resulting in R(2) of 0.96 both for the general regression and Ward-5 neural networks.
 
Range in nutrient analysis of manures for various handling systems (Klausner et al. [9])
Average annual distribution of total N inputs in irrigated corn grown on sandy loam soil (Legg and Meisinger [5]).
Corn silage response to manure applications for a 10-yr period (Ferguson et al. [69]) Type of fertilizer and application basis
Nutrient management is an integral part of profitable agrisystems, but in some areas of the United States, continued applications of fertilizer and manure nutrients in excess of crop requirements have led to a buildup of nutrient concentrations that are of environmental concern. Proper use of nutrients in livestock manures is becoming more critical for sustainability of concentrated animal feeding operations (CAFO) because new environmental regulations require that nutrients be properly applied and managed. Losses of nutrients, such as N and P can be reduced by refining the rations fed, increasing nutrient retention by livestock, moving manures from areas of surplus to deficiency, finding alternative uses for manure, using cropping and haying systems that remove excess nutrients, and using conservation practices, such as limited tillage, buffer strips, and cover crops to limit runoff and leaching. Whole farm nutrient balances are useful for educating producers about quantities of nutrients being managed and the flow of nutrients, but they can also be misleading because of spatial factors, such as uneven nutrient application that introduce environmental risks that may not be noted with a whole-farm nutrient balance. Manure utilization plans also need to deal with nutrients that potentially leave the field or production area in route to sensitive ecosystems.
 
Because nearly all the turkeys produced in the United States are the result of artificial insemination (AI), it is important to increase the efficiency of this labor-intensive practice. A semen evaluation test predicted of fertility would be extremely beneficial. Studies have shown that sperm mobility is predictive of fertility. The Sperm Mobility Test (SMT) objectively quantifies sperm mobility by measuring the density of sperm that swim through a solution of Accudenz at body temperature. This test results in a sperm mobility index score which is used to rank toms within a flock. Toms classified as having low sperm mobility have reduced fertility compared to those toms with high mobility. By using the SMT, it is possible to screen semen to determine which toms have the least chance of siring poults, then to cull them from a flock. This study attempted to determine if a reliable laboratory method for the analysis of turkey sperm mobility could be successfully modified for commercial field use in the turkey industry. Both the laboratory method and the proposed field methods yielded equivalent results. Consistently, toms classified with low mobility sperm could be identified utilizing any of the test methods evaluated. We conclude that the SMT is adaptable for on-farm use for the selection of potential sires.
 
Experimental setup used for mercury ad- sorption testing. The empty bed residence time (EBRT) was calculated from the volume of the column divided by the gas flow rate. 
Results of packed-bed experiments with activated carbons (AC) from a commercial source or made from chicken manure. The data represent the fraction of the mercury in the incoming gas (C out /C in ) that penetrated the carbon bed over time. 
Summary of surface area analysis results
Results of packed-bed experiments with unwashed activated carbons (AC) made from turkey manure (cake and litter). The data represent the fraction of the mercury in the incoming gas (C out /C in ) that penetrated the carbon bed over time. 
Overall performance of activated carbons. The pseudo distribution coefficient (K d ) value was cal- culated as cumulative adsorbed mercury (based on inlet and outlet concentration) per gram of adsorbent in the column, divided by the inlet concentration of mer- cury in air. 
The quantity of poultry manure generated each year is large, and technologies that take advantage of the material should be explored. At the same time, increased emphasis on the reduction of mercury emissions from coal-fired electric power plants has resulted in environmental regulations that may, in the future, require application of activated carbons as mercury sorbents. The sorbents could be injected into the flue gas stream, where they could adsorb the mercury. The sorbents (now containing mercury) would be removed via filtration or other means from the flue gas. Our preliminary work has demonstrated that activated carbon made from poultry manure can adsorb mercury from air with good efficiency. In laboratory experiments, an activated carbon made from turkey cake manure removed the majority of elemental mercury from a hot air stream. Other activated carbons made from chicken and turkey litter manure were also efficient. In general, unwashed activated carbons made from poultry manure were more efficient in removing mercury than their acid-washed counterparts. The results suggest that the adsorption of mercury was mainly due to chemisorption on the surface of the carbon. Other potential uses for the activated carbons are the removal of mercury from air and natural gas.
 
Single and combined effects of aflatoxin (AF) and yeast culture residue (YCR) in feed on egg production of broiler breeder hens over a 3-wk period. Each bar represents the mean of 10 hens per treatment, and the letters (a-c) indicate significant differences (P < 0.05). Control = negative control (no AF or YCR); YCR = yeast culture residue, and AF + YCR = combination of aflatoxin and yeast culture residue.
Effects of yeast culture residue (YCR) in feed on embryonic mortality of broiler breeder hens fed diets containing aflatoxin (AF)
A study was conducted to examine the effect of yeast culture residue (YCR) on the suppression of aflatoxicosis in broiler breeder hens. One hundred twenty, 35-wk-old, Cobb broiler breeder hens of the same cross were fed diets supplemented with aflatoxin (AF) (0 or 3 mg/kg) and YCR (0 or 2 lb/ton) singly and combined in a 2 x 2 factorial designed experiment. The birds were randomly assigned to pens with 3 replicates of 10 females and 1 male per treatment. Eggs laid by the hens were collected daily, stored at room temperature, and incubated every 7 d for 3 wk. Response variables analyzed were mean percentage of fertility, hatchability, hen-day egg production, egg weight, chick weight at hatch, and embryonic mortality over the 3-wk treatment period. At the end of 3-wk treatment, blood was collected from the hens and analyzed for total protein, globulin, and albumin. Aflatoxin did not negatively affect fertility. However, hen-day egg production (57.6%), percentage of hatchability (67.6%), embryonic mortality (24%), serum total protein, globulin, and albumin were significantly (P < 0.05) affected by AF. Hatch of fertile eggs from the AF-fed hens was significantly lower than the control (67.6 vs. 78.5%). The inclusion of YCR in the AF-treated diet raised the level of hatchability (74.9 vs. 67.6%), egg production (65.83 vs. 57.26%), and lowered embryonic mortality (16.8 vs. 24%). Serum globulin and albumin were lowered in the AF-fed hens but was partially restored with the addition of YCR. The data demonstrated that YCR may enhance the performance of broiler breeder hens that are provided feed contaminated with AF.
 
The profitability of using poultry litter as a fertilizer and soil amendment in cultivated agriculture was evaluated with the hopes of determining an economically optimal fertilization strategy. The traditional commercial (inorganic) fertilizer practice was compared with several hybrid litter and commercial N fertilization alternatives in terms of on-farm agro-economic effects. Six years of land management, crop yield, crop price, and fertilizer cost data were collected from 6 field sites in central Texas and utilized for economic analysis. Varying litter and inorganic fertilizer combinations resulted in minimal differences in corn and wheat yields; however, total fertilizer costs increased significantly as litter application rate increased (and commercial fertilizer rate decreased) in spite of dramatic cost increases for commercial fertilizer. The greatest average annual profits were determined to occur at the 1 and 2 tons/acre (ac) litter rates with 7 to 14% profit reductions for the commercial fertilizer-only treatment and the 3 tons/ac litter treatment. At litter rates greater than 3 tons/ac, diminishing returns were observed as fertilizer costs increased with no compensating greater yields to provide offsetting revenues. It is important to note that this economically optimal annual litter rate of 1 to 2 tons/ac is also environmentally optimal according to nutrient runoff and soil nutrient data collected on-site. These results provide the scientific basis to support the use of litter as a cost-effective, environmentally friendly fertilizer alternative in this and similar regions.
 
The use of chemicals in food plant sanitation for removing and killing microorganisms could be reduced by the use of alternative nonchemical interventions. Supercharged negative air ionizers have shown potential to effectively reduce airborne and surface microorganisms. In our earlier studies, a small chamber, controlled at 85% relative humidity and supercharged with a −25 kV electrostatic space charge system (ESCS), was used to transfer a strong negative charge to bacteria on stainless steel surfaces. The ESCS treatment caused the levels of biofilm bacteria from chicken carcass rinses to be significantly decreased with 99.8% efficiency at a distance of 18 cm with ion densities of 106 negative ions/cm3 or more. In the present study, effects of the −25 kV charge of ESCS on specific pathogens important for food safety were studied. Treatment of Campylobacter jejuni, Escherichia coli, Salmonella enteritidis, Listeria monocytogenes, and Staphylococcus aureus achieved up to a 4 log reduction with 99.9% reduction efficiency in 3 h. Treatment of bacterial spores of Bacillus stearothermophilus achieved up to a 3 log reduction with a 99.8% reduction efficiency in 3 h. These significant reductions for 5 species of pathogenic bacteria and bacterial spores suggest that the ESCS is a promising alternative treatment for reduction of microbial load in a food-processing facility with the potential to reduce the amount of antimicrobials used.
 
Experimental design for each of 3 replications. L* = lightness; a* = redness; b* = yellowness. 
Temperature of breast muscle of broiler carcasses during air and immersion chilling. 
Effect of broiler carcass chilling method on raw and cooked breast fillet color
Effect of broiler carcass chilling method on raw breast fillet marination pickup and cooked fillet yield and shear
Pearson's correlation coefficients for weight gain and loss during chilling, cooked meat shear force, cook yield, marinade uptake, and color values of raw fillets
A study was conducted to investigate the effect of chilling method on broiler carcass skin color, moisture retention, breast fillet quality, and functionality. One hundred fifty eviscerated broiler carcasses were removed from a commercial processing line before chilling, transported to the laboratory, weighed, and chilled by dry air or immersion in ice water. Postchill carcasses were weighed for moisture uptake or loss and held on ice at 4°C for 24 h. Carcass skin color was measured immediately after chilling and after storage. After storage, fillets were deboned, marinated, and cooked. Fillet color was measured on the medial surface before marination and after cooking. Cooked fillet shear values were determined using an Allo-Kramer multiple blade. After 150 min of air chilling, carcasses lost 2.5% of prechill weight, and weight loss ranged from 2.2 to 3.5%. Moisture uptake during immersion averaged 9.3% of the prechill weight but varied widely with a range of 3.4 to 14.7%. Immediately after chilling, breast skin for immersion-chilled carcasses was significantly lighter (higher L*), less red (lower a*), and less yellow (lower b*) than the breast skin color for air-chilled carcasses. Storage time improved appearance (lighter skin color) of air-chilled carcasses. Raw and cooked fillet color, fillet marination pickup, and cooked fillet tenderness were not affected by chilling method. Cook yield for fillets deboned from immersion-chilled carcasses was significantly lower than fillets from air-chilled carcasses.
 
Numbers of Campylobacter recovered from whole-carcass rinse samples of feathered carcasses (prepick), defeathered carcasses (postpick), fully processed chilled carcasses (chilled), and fully processed chilled carcasses exposed to airborne contamination at the defeathering machine (chilled exposed). Error bars represent 95% confidence intervals (it can be stated with 95% confidence that the true population mean falls within this range).  
The enteric pathogen Campylobacter can be carried into poultry processing facilities on and within live birds. Numbers of Campylobacter recovered from carcasses decrease after scalding but increase during feather removal. Mechanical feather picking causes mist as well as particles of dust, feathers, feces, and other matter to become airborne around the machine. This study was conducted to determine if Campylobacter associated with broilers during defeathering can become airborne and contaminate other carcasses in or around a commercial defeathering machine. Carcasses with low numbers of Campylobacter were hung near an operating commercial feather picker where they were exposed to airborne contaminants for 1min. Low numbers of Campylobacter were detected in the air near the picker. However, microbiological culture of carcasses after exposure to airborne contamination in the picker room revealed that they had no more Campylobacter than unexposed carcasses. These data suggest that airborne contamination does not contribute to the high numbers of Campylobacter routinely found on defeathered carcasses.
 
Salmonella spp. present in pasteurized egg albumen are often difficult to recover by direct plating because of thermal injury and the presence of innate iron binding and other antimicrobials in egg white. The literature has reported a multiplicity of selective and nonselective media used to recover heat-injured Salmonella, to measure the proportion of injured cells, or both. This study compared the proficiency of selective and nonselective plating media for supporting colony development or for assessing bacterial injury of heat-stressed Salmonella from egg albumen. A 6-strain composite of Salmonella was added to albumen (pH 9.0), heated at 53.3°C for 3.1 min, and plated on 26 nonselective and 22 selective media. Recovery of heat-injured salmonellae varied little (< or = 0.52 log cfu/mL) among the nonselective media tryptic soy agar, plate count agar, dextrose tryptone agar, or brain heart infusion agar, regardless of the manufacturer. Selective media that were optimal for recovery of salmonellae from albumen included 3 brilliant green agars, Levine eosin methylene blue agar, and bismuth sulfite agar, which recovered more cells (P < or = 0.05) than selenite-cystine, tetrathionate, xylose-lysine-tergitol-4 , xylose lysine deoxycholate, or Rappaport-Vassiliadis agars. The results of this study may assist in choosing selective or nonselective media to maximize the recovery of Salmonella from thermally treated albumen.
 
Two experiments were conducted to assess dietary amino acid density responses on mixed-sex broiler live performance, meat yields, and economics from 36 to 60 d. In experiment 1, broilers were fed a common feeding program to 35 d. Dietary treatments were high (H), moderate (M), and low (L) amino acid density from 36 to 47 d of age and H or L amino acid density from 48 to 60 d of age. Dietary treatments were high-high (HH), high-low (HL), moderate-low (ML), and low-low (LL) during a 60-d production period. In experiment 2, common diets were provided from 1 to 47 d of age. Dietary treatments were H, M, L, and suboptimum (S) amino acid density and fed from 48 to 60 d of age. In experiment 1, increasing dietary amino acid density to HH improved cumulative feed conversion (1 to 60 d) by 4 points over the ML- and LL-fed birds. Broilers provided the HH regimen had 0.6% more total breast meat yield than the LL-fed birds. In experiment 2, broilers fed the H feeding regimen lowered cumulative (1 to 60 d) feed conversion by 3, 5, and 6 points and reduced abdominal fat percentage by 0.28, 0.23, and 0.23%, respectively, compared with the M-, L-, and S-fed birds. Decreasing dietary amino acid density from H to S reduced total breast meat weight and yield by 47 g and 0.82%, respectively. In general, feeding HL (experiment 1) and H (experiment 2) diets increased gross feed margins over the other dietary treatments with diverse diet cost and meat price scenarios.
 
Two experiments (EXP) were conducted to evaluate the interactive effects of dietary AME and amino acid (AA) density (total basis) on broiler chickens from 42 to 56 d of age. In EXP 1, diets were formulated to contain low AME (3,140 kcal/kg) and moderate AME (3,240 kcal/kg) in combination with moderate AA (16.2% CP, 0.88% Lys, and 0.75% TSAA) and high AA (18.0% CP, 0.98% Lys, and 0.83% TSAA) and fed to male broilers. Dietary treatments in EXP 2 were diets formulated to contain moderate AME (3,220 kcal/kg) and high AME (3,310 kcal/kg) combined with moderate and high AA concentrations used in EXP 1 and fed to male and female broilers. In general, dietary AME and AA did not interact to influence growth and meat yield responses. Broilers provided the low AME diet in EXP 1 consumed more feed and had poorer feed conversion but had higher total breast meat yield than birds fed the moderate AME diet. In EXP 2, broilers fed the high AME diet from 42 to 56 d had increased BW gain, decreased feed consumption, and improved feed conversion. Feeding the high AA diets in both EXP decreased feed consumption, improved feed conversion, and increased total breast meat yield. Nutritionists establishing nutritional programs for heavy broilers late in development from 2.5 to 3.6 kg may need to consider increasing AA density to optimize breast meat yield. Increasing the AME content of the diet improves feed conversion but not breast meat yield.
 
It has been a tendency for broiler integrators in the US to reduce dietary nutrient density to lower overall input costs of broiler production. Dietary nutrient density is routinely scrutinized because feed represents over half of the live production costs. Numerous nutritionists and researchers from the supplier side of poultry production are arguing that the reduced dietary nutrient density regimen currently employed by some integrators is not an effective means of increasing profitability, especially when producing large, high-yield broilers for markets geared toward saleable white meat. This research evaluates nutrient density in various phases throughout life in Ross 508 male and female broilers to better understand the impact of reduced dietary nutrient density, mimicking the reduced dietary cost scenarios used by some broiler integrators. Diets were provided to broilers in 4 phases from 1 to 14, 15 to 28, 29 to 35, and 36 to 49 d of age, in which treatments of high (H), medium (M), and low (L) amino acid densities were used. The combinations of nutrient density and feeding phases resulted in treatments of 1) HHHH, 2) HHML, 3) HHLL, 4) HMML, 5) HMLL, 6) HLLL, 7) MMMM, and 8) LLLL. Male broilers were more sensitive to amino acid density reductions than females. Reduction of nutrient density in the early feeds was detrimental for most parameters tested. High nutrient density throughout life (HHHH) optimized breast meat yield, whereas reductions in nutrient density reduced growth and breast meat yield and increased corrected feed conversion and leaf fat. Integrators feeding slow-maturing, high-yield broilers with low and moderate nutrient dense diets may produce broilers with suboptimal growth and breast meat yield, although moderate diets may result in good feed conversion.
 
Providing broilers diets formulated to a high amino acid density early in life improves subsequent growth performance and meat yield. Diets formulated to high amino acid concentrations beyond 5 wk of age may increase breast meat yield but may not be economically justified. This study examined growth, meat yield, and economic responses of broilers provided diets varying in amino acid density from 36 to 59 d of age. Birds were given a 4-phase feeding program: starter (1 to 17 d), grower (18 to 35 d), withdrawal-1 (WD1; 36 to 47 d), and withdrawal-2 (WD2; 48 to 59 d of age). All birds were fed a common, high amino acid density diet to 35 d of age (HH). Broilers were provided diets characterized as being high (H), moderate (M), or low (L) in amino acid density for the WD1 and WD2 periods. Dietary treatments were HHHH, HHHM, HHHL, HHMM, HHML, and HHLL from d 1 to 59, with H, M, and L representing the diets fed during each of the 4 periods (starter, grower, WD1 and WD2). Cumulative feed conversion was improved when the HHHH feeding regimen was fed, whereas other final live performance measurements were not affected. Decreasing amino acid density (HHLL and HHHL) limited yields of breast fillets, tenders, and total white meat when compared with the HHHH regimen. As amino acid density decreased from HHHH to HHHM, HHMM, and HHML, carcass yield and breast meat yield were not affected. In general, providing the HHHH feeding regimen increased economic gross feeding margin compared with the other dietary treatments.
 
Partial front view, showing major components, of chamber acid trap system for determining NH 3 losses from litter or cake samples. DI = deionized water.
Mean cumulative N recovered, representing NH 3 losses from broiler litter samples (litter used for 18 flocks), and the relative standard deviation in measurements over time in the laboratory chamber acid trap sys- tem.  
Greater understanding of the mechanisms affecting NH3 volatilization from reused broiler bedding is needed to determine pathways for mitigating NH3 emissions. A chamber acid trap (CAT) system was developed to provide an improved laboratory method for determining NH3 volatilization from litter or cake samples and for assessing treatment technologies to decrease NH3 losses from poultry litter. The CAT system offers precision control of air flow rate through sample chambers as well as straightforward, precise determination of the amount of N volatilized. This article outlines the basic setup of the CAT system. The system can be utilized and modified for researching specific mechanisms involving physical, chemical, or biological treatments affecting NH3 volatilization from litter or cake.
 
Geometric means for NH 3 concentration at the vertical measurement locations: the litter surface, 1 ft above the surface, and 3.3 ft above the litter surface for d 40 of flock 1 (mid-September on fresh litter) and d 42 of flock 2 (early December on reused litter). For each flock, differing letter designations indicate significant differences in measurement height for NH 3 concentration (P ≤ 0.05; flock 1 LSD = 1.07 ppm; flock 2 Lsd = 1.04).
Geometric means for NH 3 concentration measured down the center of the house at positions: 100 ft toward cooling pads, middle, and 100 ft toward exhaust fans, on d 40 of flock 1 (mid-September on fresh litter) and d 42 of flock 2 (early December on reused litter). For each flock, differing letters indicate significant differences down the center of the house for NH 3 concentration (P ≤ 0.05; flock 1 LSD = 1.07 ppm; flock 2 LSD = 1.04).
Geometric means for NH 3 concentration measured by various instruments: the Innova photoacoustic multigas analyzer, 2 electrochemical gas leak detectors (Manning 1 and 2), and pull tubes for d 40 of flock 1 (midSeptember on fresh litter) and d 42 of flock 2 (early December on reused litter). For each flock, differing letters indicate significant differences among instruments for NH 3 concentration (P ≤ 0.05; flock 1 LSD = 1.08 ppm; flock 2 LSD = 1.05).
The broiler industry is not immune to the problematic nature of NH3 production in animal rearing facilities. Though the headlines of today focus on environmental impact considerations, the detrimental effects of the house air quality on farmers and birds remain considerable for industry viability. This research investigated the vertical stratification of in-house NH3 combined with sampling position down the center of the house and with different NH3 analysis technologies. The results indicated that reuse of litter and house ventilation correlate to trends in NH3 concentration at particular measurement heights. When tunnel ventilation was primary, NH3 concentrations decreased vertically with increasing distance from the litter surface. However, with lower outside temperatures, little ventilation, and a stagnant house atmosphere, no concentration gradient was evident. The work also demonstrated significant variability among professionally calibrated instruments and traditionally used pull tubes. Characterization of interior air quality of broiler houses should consider sampling height to effectively address bird exposure.
 
The meat industry routinely determines fat content of meat for quality monitoring and processed product formulation. Meat, as a raw material, is extremely variable and may range from 1 to 65% fat. Fat analysis on a batch-by-batch basis is essential. The reference methods for fat are typically time consuming and generate hazardous waste [1]. In the past 10 yr, near-infrared reflectance (NIR) and transmittance (NIT) spectroscopy have gained widespread use for analyses of quality constituents in many materials. Near-infrared spectroscopy relies on a reference method for calibration and instrument standardization. However, it is often preferred to reference methods because it is rapid, accurate, and cost effective; it does not require skilled operators; and it does not generate hazardous waste. The use of NIT for the prediction of fat in boned raw poultry breast muscle, trimmings, and raw finished product (chicken nuggets) was investigated in this study. We used a database supplied by the NIT instrument manufacturer and samples collected from a local processing plant to develop fat calibration models with an error of 0.70 and 0.33% fat, respectively. Fat calibration models were validated with local processor samples. The standard error of performance was 0.84 and 0.38% fat for the instrument manufacturer and local processor calibration, respectively. Typical within-product standard errors for other rapidmethods are 0.9 and 1.6%for Banco andUnivex rendering, respectively [2]. Badcock fat has been rejected as an official method due to loss of accuracy for samples greater than 27% fat and high bias for samples less than 27% fat [2]. Standard errors for Official AOAC Soxhlet type methods have ranged from 0.41 to 1.14% for fat [1]. USDA performance criteria for repeatability require standard errors of less than 0.63 for fat [1]. This study supports that NIT can be a useful tool in the poultry processing industry for fat analysis in quality monitoring and processed product formulation.
 
Because commercial broilers may be bruised at any time during production and even up to the time of slaughter, minimizing bruising requires a clear understanding of when and how it occurs. The present study was conducted to investigate the relationship between the age, visual appearance, and histological characteristics of a bruise. Market-aged broilers were anesthetized, bruised on the breast, wing, and drum, and processed 0, 1, 6, 12, or 24 hr after receiving the bruises. Bruise color measurements revealed that as their age increased, breast bruises became darker (higher delta L; changes in lightness value), whereas wing and drum bruises became lighter (lower delta L). Redness and yellowness of breast bruises were not significantly different at any of the bruise ages. With increasing bruise age, wing bruises became less red and less yellow, and drum bruises became more red and more yellow. Histological tissue samples showed that drum bruises were more severe than breast or wing bruises at all time intervals. For all bruises, maximum delta L and tissue edema occurred in carcasses of broilers injured 6 hr before processing.
 
Effectiveness of Timsen and H 2 O 2 treatments to eliminate Salmonella Typhimurium inoculated onto fertile eggs by fecal smear
Effectiveness of Timsen and H 2 O 2 treatments to eliminate Salmonella Typhimurium inoculated onto fertile eggs by immersion
Varying levels (10⁵ to 10⁷/egg) of Salmonella Typhimurium were inoculated onto fertile hatching eggs by immersion. After this, the inoculated eggs were untreated (control), water treated, hydrogen peroxide (1.5%) treated, or Timsen treated (n-alkyl dimethyl benzyl ammonium chloride as a commercial bactericide-fungicide). Hydrogen peroxide was superior to Timsen as an egg treatment to eliminate artificially inoculated Salmonella from fertile eggs, but one-third of the treated eggs remained Salmonella positive. This study demonstrates how difficult it is to eliminate Salmonella that contaminate fertile hatching eggs. Until a more effective system or process is devised and commercially implemented, Salmonella and other organisms will continue to pass from one generation to the next through the fertile egg.
 
Two trials were conducted with male broilers to determine the effect of dietary lysine on deaths due to ascites. Starter diets contained 1.13, 1.20, 1.28, and 1.35% dietary lysine; grower diets contained 1.02, 1.09, 1.16, and 1.23% lysine. Neither deaths due to ascites nor total deaths were affected by treatment in Trial 1. A significant effect of treatment on deaths due to ascites was observed in Trial 2, but deaths for the highest lysine level were not different from the lowest lysine level. Heart weight and ventricle weights were not affected by treatment. These results suggest that ascites is not attributable to dietary lysine levels in commercial diets.
 
Panel A: A 4.5-mm diameter stage X chicken blastoderm is characterized by a dense ring, the area opaca, enveloping the less central region, area pellucida. The mottled surface of the area pellucida is due to aggregates of cells. Panel B: A 4.5-mm diameter stage XI chicken blastoderm has the same characteristics as the stage X blastoderm, except that the aggregates of cells appear denser, and one side of the area pellucida appears denser due to the forming hypoblast. Panel C: This 4-mm diameter stage VIII mulard blastoderm shows incomplete area pellucida formation and a relatively wide area opaca. Panel D: This 4-mm diameter late stage VII Guinea fowl blastoderm shows the beginning of the area pellucida and area opaca formation. Panel E: This stage VI Muscovy duck blastoderm shows no sign of area pellucida formation and is nearly uniform in its 3.5-mm diameter. Panel F: This turkey’s unfertilized 3.5-mm diameter germinal disc, which is representative of most species and strains examined, is recognized by its dense white appearance and is accompanied by a variable number of vacuoles in the white yolk area. When viewed without magnification, the dense white area appears eccentric and asymmetrical due to the random distribution and density of the vacuoles. 
Incubation conditions
The distribution (%) of developmental stages (Eyal-Giladi and Kochav) of embryos from oviposited eggs stored up to 72 h
Normal tables of chicken embryo development are used to define specific stages of morphogenetic progression from the first cleavage divisions through hatching. Although established for the turkey and Pekin duck, the application of the normal tables of chicken embryo development to other birds of commercial and research importance needs be examined. Chicken, turkey, Japanese quail, and Pekin duck blastoderms from oviductal eggs showed differences in the rate of development that were inversely correlated with egg size. Oviposited eggs from these and additional species (goose, Muscovy and mule ducks, and Guinea fowl) were examined after 24 to 72 h of storage and at 6-h intervals up to 72 h of incubation. There was variation in the developmental stages of the blastoderm at the time of oviposition between and within the species and strains examined. Although it is recognized that the temporal rate of development will differ between different species and strains, the external features of any embryo in any given stage will be nearly identical.
 
Avian influenza (AI) vaccines are a viable emergency tool for use in a comprehensive strategy for dealing with high-pathogenicity AI in developed countries. However, the available doses of inactivated AI vaccine are limited to national vaccine banks and inventory stocks of some commercial biologics manufacturers. To determine if the available vaccine doses could be stretched by using reduced vaccine dose but maintain adequate efficacy, a study was conducted to determine if 3-wk-old specific pathogen-free White Leghorn chickens vaccinated with full, 1/2, 1/4, and 1/10 doses of an inactivated H5N9 AI vaccine would be protected against a high-dose challenge of H5N1 highly pathogenic AI virus given 4 wk later. At all 4 AI vaccine doses, the AI-vaccinated chickens were protected from disease and death, but all the sham-vaccinated chickens developed clinical signs and died. There were no differences between the full, 1/2, and 1/4 dose AI vaccine groups for serological titers at 7 wk of age, or for cloacal and oropharyngeal titers of challenge virus shed at 2 d postchallenge. However, the 1/10 dose group had significantly reduced hemagglutination inhibition titers at 7 wk compared with 1/4 dose, and the 1/10 dose group had more chickens shedding challenge virus from the oropharynx than the full dose group. Most importantly, the mean protective dose was 1/50 dose, and using the international regulatory standard of 50 mean protective doses for Newcastle disease vaccine as a guide, the full dose of the H5N9 AI vaccine would be the minimum dose acceptable for use in the field. Use of the full vaccine dose is especially important, because protection in commercial chickens in the field is typically less than seen in experimental studies in specific pathogen-free chickens in the laboratory.
 
These experiments sought to increase the shelf life of poultry by treatment with a disodium ethylenediametetra-acetate (EDTA) and nisin (NIS) combination and storage under modified atmosphere packaging (MAP) or vacuum packaging (VP). Chicken drummettes were soaked with various combinations of EDTA and NIS for 30 min at 15°C and stored at 4°C. Parts treated with EDTA-NIS stored under VP had significantly lower (P<or=. 01) total aerobic plate counts than untreated controls stored under aerobic conditions. EDTA-NIS increased shelf life by a minimum of 4 days when packaged in aerobic conditions and a maximum of 9 days when vacuum packed. A second experiment evaluated the VP and EDTA-NIS combinations in more detail. Parts treated with EDTA-NIS stored under VP had significantly different (P<or=. 01) aerobic counts from parts treated with EDTA-NIS stored under aerobic conditions or untreated control parts. EDTA-NIS treatment increased shelf life 4 to 7 days in the second experiment. The results indicate that a combination of EDTA-NIS treatment and vacuum packaging has the potential to significantly increase the shelf life of raw processed poultry.
 
Current systems for preslaughter gas stunning and killing of broilers use process gases such as CO2, N2, Ar, or a mixture of these gases with air or O2. These systems, known as controlled-atmosphere stunning-killing systems, work by displacing O2, ultimately to induce hypoxia in the bird, leading to unconsciousness and death. In this study, mechanical removal of O2 by rapidly reducing air pressure was investigated as an alternative to controlled-atmosphere stunning-killing systems. Low atmospheric pressure systems could offer advantages in worker safety and operational gas cost because they operate solely with atmospheric air. This study comprised 2 experiments, one to define the initial range of effective pressures, and the second to determine a recommended process pressure. In experiment 1, 48 female broilers, aged 63 d, were subjected to 6 different pressure treatments, ranging from 70.9 to 17.8 kPa. In experiment 2, 56 male broilers, aged 60 d, were subjected to 7 different pressure treatments, ranging from 35.3 to 17.8 kPa. Birds were individually placed in an airtight vessel and exposed to a pressure treatment for 2 min after the final pressure was attained. Results from experiment 1 showed that the effective range of pressure was between 29.5 and 17.8 kPa, with only 25% of the birds exposed to 29.5 kPa surviving and none of the birds exposed to 17.8 kPa surviving. Experiment 2 used a finer resolution of pressure increments, and the estimated pressure level lethal for 99.99% of the birds was determined to be 19.4 kPa.
 
Formaldehyde gas fumigation has been recognized for many years as an effective decontamination procedure to sterilize a variety of airborne and surface microorganisms. Although automated systems are commercially available to generate formaldehyde gas, they tend to be very expensive and more complicated than is necessary for many applications. Also, they do not provide any means of assuring that gas levels are safe for occupancy by personnel following a treatment. Over a period of several years, areas in approximately 15 buildings at the Southeast Poultry Research Laboratory in Athens, GA have been decontaminated with a very basic, manually mixed, formaldehyde gas generation system. The decontamination was followed by several hours of mechanical clearing of the gas, using remotely operated exhaust fans. Interest in maximizing worker safety and providing simple and affordable fumigation led to the design of the automated systems described in this paper - one for formaldehyde gas generation, the other for formaldehyde gas neutralization. Proper use of these systems minimizes formaldehyde exposure risk for workers. Both systems can be easily constructed, and they have been used successfully for several years.
 
Every summer in the southeastern U. S. , many broilers die from heat stress due to a combination of high temperature and high humidity. Managers tend to ventilate open-sided broiler houses during summer primarily with large fans that use a large amount of electricity. In theory, if the wind velocity in the houses exceeds 2.0 miles per hour (mph), broilers receive adequate natural ventilation and can be reared safely without fans. However, a system is needed to activate fans when wind speed and direction are inadequate to remove metabolic heat and moisture production. Research was initiated to develop a system for summer rearing that could automatically turn fans off when the wind velocity exceeded 2.0 mph. Two separate wind monitoring devices were interfaced with fans of a curtain-sided broiler house that turned fans off when sufficient wind was present for natural ventilation. Proper interior conditions (monitored continuously during testing) were maintained while the recorded average fan run-time was reduced by as much as 50%.
 
Mycoplasma gallisepticum (MG) is a persistent, highly transmissible chicken and turkey pathogen. Infections of the organism can yield significant losses in performance and associated economics to all sectors of the poultry industry. In this paper, potential and realized effects of MG on the poultry industry are discussed along with currently available and developing control methods. Available methods of MG control largely include stringent biosecurity and biosurveillance practices within the turkey and broiler sectors of the poultry industry and live attenuated MG vaccine strains that are approved for use only within the commercial egg layer industry. Although largely effective, MG breaks within these industries still occur, demonstrating that further means of control are required. Alternative means for consideration include bacterins and subunit vaccines, although their applicability may be limited by associated vaccination protocols. Further means under consideration include novel live attenuated MG strains and recombinant bacterial and viral species. Optimally, control methods would be applicable to all poultry and be safe, cost effective, and efficacious. Current research regarding novel MG vaccines is addressed herein.
 
Counts of total aerobic bacteria, coliforms, and Escherichia coli 1 and prevalence 2 of Salmonella and Campylobacter recovered from the flooring of chicken transportation cages after 3 stages of cleaning
A study was conducted to determine the effectiveness of an automated commercial washing system designed to clean chicken transportation cages. Surface swabs of flooring in chicken transport cages were collected before and after washing and again after sanitizer application and evaluated for recovery of bacteria. Cage wash water samples (CWW) were collected and assessed chemically and microbiologically. Washing cages significantly reduced levels of total aerobic bacteria, coliforms, and Escherichia coli recovered from flooring by 1.3, 1.6, and 1.5 log10 cfu/cm2, respectively. Levels of total aerobic bacteria, coliforms, and E. coli on flooring were further reduced by 0.7, 0.6, and 0.7 log10 cfu/cm2 after sanitizer application. Prevalence of Salmonella on unwashed flooring (1/27 positive), washed and sanitized flooring (0/27 positive), and in the CWW (1/9 positive) was low. Prevalence of Campylobacter (7/27 positive) on unwashed flooring decreased significantly when cages were washed and sanitized (2/27 positive). Counts of total aerobic bacteria, coliforms, and E. coli in CWW ranged from 2.0 to 4.0 log10 cfu/mL, and 1 of 9 CWW was positive for Campylobacter. Although the CWW collected from the second washing station appeared darker than the CWW collected from the first washing station, there was no statistical difference in total solids, total suspended solids, total dissolved solids, and chemical oxygen demand. The present study demonstrates that washing and sanitizing chicken transport cages reduces, but does not completely eliminate, bacterial contamination on the flooring surface.
 
Incidence of Campylobacter and Salmonella in unabsorbed yolk sacs from commercial broiler carcasses Sample site Item Campylobacter 1 Salmonella 1
In the developing avian embryo, the main energy source is the yolk. Toward the end of the incubation period, the remaining yolk sac is internalized into the abdominal cavity. At hatch, the remaining yolk comprises 20% of the chick's BW and provides the nutrients needed for maintenance. Posthatch, chicks rapidly initiate the transition from yolk dependence to the utilization of exogenous feed. However, at present, it is not known what types of bacteria are found to be associated with unabsorbed yolk sacs from market-age broilers. For Experiment 1, one hundred 6-wk-old defeathered broiler carcasses were obtained from a commercial processing facility during each of 3 visits. In the second experiment, one hundred 8-wk-old defeathered broiler carcasses were obtained from a different commercial processing plant on 4 separate occasions. For both experiments, each carcass was aseptically opened and inspected for the presence of an unabsorbed yolk sac. Three to 5 carcasses containing a free-floating yolk sac (within the abdominal cavity) and the yolk stalk (without a yolk sac) and 3 to 5 carcasses containing an attached yolk and yolk stalk from each repetition were randomly selected and analyzed for levels and types of total aerobic bacteria (APC), Enterobacteriaceae (ENT), and for the presence of Campylobacter spp. and Salmonella serovars. The APC ranged from log 3.3 to >log 6.0, and the ENT ranged from log 2.8 to >log 6.0. Staphylococcus spp. and Streptococcus spp. were the predominant organisms in APC, whereas Escherichia coli and Hafnia alvei were found to comprise the ENT. Campylobacter spp. was found in 29% of the yolk stalks, 32% of the attached yolk sacs, and 13% of the free-floating yolk sacs. All Campylobacter isolates were determined to be Campylobacter jejuni, except for 1 attached yolk and yolk stalk, which was Campylobacter coli. Salmonella serovars were found in 26% of the yolk stalks, 48% of the attached yolk sacs, and 23% of the free-floating yolk sacs, and the majority of Salmonella isolates were Salmonella Typhimurium. The significance of these bacterial reservoirs and carcass contamination during processing is yet to be determined.
 
The bactericidal effect of mixtures of KOH and lauric acid (LA) on the microflora of broiler carcasses was examined. Carcasses were washed by shaking in KOH-LA for 1 min on a mechanical shaker. In one set of experiments, the population of bacteria recovered from carcasses following each of 3 successive washes in 1.0% KOH-2.0% LA or in distilled water (control) was enumerated. The number of total plate count bacteria, Campylobacter, and Escherichia coli in aliquots of whole-carcass-rinses of the washed carcasses was determined. Results indicated that fewer bacteria were generally recovered from carcasses after each successive wash in KOH-LA or distilled water, but significantly fewer bacteria were recovered from carcasses washed in KOH-LA than from carcasses washed in distilled water. Bacteria recovered from carcasses after the first and third wash in KOH-LA were identified using the MIDI Sherlock Microbial Identification System. Gram-positive and gram-negative bacteria were identified in the bacterial flora of carcasses washed once in KOH-LA; however, only gram-positive cocci were identified in the bacterial flora of carcasses washed 3 times in KOH-LA. Additional experiments were performed to compare the number of bacteria recovered from carcasses washed 2 times in 0.25% KOH-0.5% LA, 0.5% KOH-1.0% LA, or 1.0% KOH-2.0% LA or in distilled water (control). Results indicated that significantly fewer bacteria were recovered from carcasses washed in higher concentrations of KOH-LA than from carcasses washed in lower concentrations of KOH-LA. Findings from these experiments show that washing carcasses in KOH-LA can reduce carcass contamination by bacteria responsible for human foodborne diseases and spoilage of fresh poultry.
 
Broiler transport coops become soiled with feces during use. When this fecal matter contains Campylobacter, the result can be cross-contamination of subsequent flocks that were previously free of this important human pathogen. Because washing and sanitizing coops requires large amounts of water and is not always effective enough to justify the expense, few broiler companies wash and sanitize dump coops between flocks. In this lab-scale study, a tap water spray was effective in lowering the numbers of bacteria, including Campylobacter, associated with broiler transport coop flooring. Immersion in a chemical sanitizer after spray washing did not enhance the antibacterial effect. It is possible that sanitizing treatments could be made more effective by using higher concentrations of chemicals, high temperature treatment, or high pressure or repeated applications of water spray. However, such changes would come at a cost. Research is needed to find new and innovative ways to lower bacterial numbers in broiler transport coops without undue use of water and the associated expense.
 
Bacteria (including salmonellae) can be pulled into and through the shell and membrane of broiler hatching eggs as they cool. When this occurs, salmonellae are out of reach of a surfaceapplied chemical treatment, because direct contact is usually required to achieve a kill. Over many years of research, a large number of disinfectant chemicals have been tested on hatching eggs. We have found H2O2 (1.4%) to be a fairly effective disinfectant to reduce Salmonella that is artificially inoculated onto hatching eggs. The objective of the present study was to determine whether the efficacy of H2O2 could be enhanced by utilizing vacuum and a surfactant to remove air and reduce surface tension within the eggshell, enabling the bactericide to penetrate deeper into the egg to kill Salmonella. Eggs were inoculated with nalidixic acid-resistant Salmonella typhimurium. Inoculated eggs were treated with H2O2 with or without a surfactant and with or without the application of vacuum to facilitate shell penetration. Thirty percent of eggs exposed to H2O2 with surfactant and vacuum were still positive for the marker Salmonella. Although this represents a decrease in number compared with a water control, 30% remained contaminated. Results demonstrate the difficulty involved in reaching and killing Salmonella that has penetrated the hatching egg, even with an effective bactericide.
 
In previous studies, immersion in hydrogen peroxide and phenol reduced Salmonella-positive eggs without reducing hatchability. This study was carried out to determine if three consecutive dips in a chemical was more effective than a single immersion to eliminate Salmonella from hatching eggs. Eggs were inoculated with a marker strain of Salmonella typhimurium by submerging the egg in a solution containing low numbers (10³) or high numbers (10⁵) of the organism. After allowing the eggs to dry, they were immersed for 1, 2, and 3 min in water, a 1.4% solution of hydrogen peroxide, or a 0.39% solution of phenol. With the low inoculation, Salmonella were eliminated from an additional 22%of the eggs when three dips were used as compared to a single dip.
 
Performance of poults fed diets containing wild-type (NB) and low phytate barley (MB) A
Phosphorus and Ca retention of poults fed diets containing wild-type (NB) and low phytate barley (MB)
Analytical nutrient content of low phytate and wild-type barley
A study was conducted to determine whether P in a low phytic acid mutant barley (Hordeum vulgare L. ; MB) containing the lpa 1-1 allele is more available than P in a near-isogenic, wild-type barley (NB). The MB contained 0.21% non-phytate P (nP) (estimated available P; aP) and 0.35% total P (tP), whereas NB contained 0.11% aP and 0.35% tP. A completely randomized design was used with 150 1-d-old male poults randomly assigned to five treatments (six pens of five poults per treatment) for 21 d. The five treatments were 1) a NB diet containing 0.30% aP, 0.41% tP, and 1.0% Ca; 2) a MB diet containing 0.36% aP, 0.41% tP, and 1.0% Ca; 3) a NB diet similar to Diet 1 but with KH2PO4 added to increase the aP to 0.36% (0.47% tP) to match the aP in Diet 2; 4) a MB diet containing 0.60% aP, 0.86% tP, and 1.2% Ca; and 5) a NB diet containing 0.60% aP, 0.92% tP, and 1.20% Ca. Performance and bone ash were significantly lower (P < 0.05) in poults fed Diet 1 compared with those in poults fed Diet 2. Performance and bone ash were similar (P > 0.05) in poults fed Diets 2 and 3 and in poults fed Diets 4 and 5. Poults fed Diet 1 retained 13.9% more P than did poults fed Diet 2 (P < 0.05). Poults fed Diets 2 and 4 retained 11.9 and 4.9% more P than poults fed Diets 3 and 5, respectively (P < 0.05). Poults fed MB diets excreted 41% less P than did poults fed NB diets when barley was the sole source of phytic acid in the diet. Results of the current study indicate that P in MB is more available than P in NB, and decreasing the phytate content did not compromise the nutritional value of MB.
 
Dairy compost (DC) was evaluated as a possible bedding substrate for brooding turkeys. This study compared livability, weight gain, and footpad score between pine shavings (PS) and DC for 2 strains of turkeys. There were no significant differences in either strain for livability through 35 d of age. Mean body weight at 35 d in the DC treatment compared with PS was less in strain B but not significantly different in strain A. Footpad score in the DC treatment was significantly greater in both strains compared with PS; however, brooder performance as measured by mortality and ambulatory disturbances was not affected in either strain. Results suggest DC may have limited but possible value as a bedding material for brooding turkeys.
 
Removing the large breast muscle from broiler carcasses prior to the resolution of rigor mortis results in tough cooked meat. However, the practice of holding carcasses or front halves 8 to 24 hr after chilling prior to deboning to ensure tenderness in the cooked meat is costly with regard to refrigerated space, equipment, and labor. This study determined the effect of extending the chilling time (1, 2, or 3 hr) and subjecting the deboned breast muscles to belt flattening on subsequent physical dimensions (length and width), yield, and tenderness of the cooked meat. Maximum length, width, and weight of each muscle were recorded before and after flattening, and cooked yield and objective texture (tenderness) were evaluated to determine if a combination of the two treatments would eliminate the need to age carcasses for prolonged times prior to deboning. For objective texture, increasing the chilling time resulted in less force necessary to shear the cooked meat, and flattened breasts required less force to shear than did the unflattened breasts. Belt flattening resulted in a loss in weight and an increase in surface area (length and width) of the raw muscle. The combination of carcass chilling for 2 hr followed by belt flattening resulted in cooked meat that would be considered “very tender.”
 
Campylobacter is a very important human foodborne pathogen that is present in commercial broiler flocks. This organism lives in the intestinal tract of broilers without causing avian disease. However, commercial poultry products are frequently implicated as vehicles of human campylobacteriosis. Flocks are typically free of Campylobacter for the first 2 to 4 wk of broiler production. A flock may be completely free of Campylobacter 1 wk but entirely colonized by the next week. This study showed the incidence and level of Campylobacter transmission to pen mates of various ages after exposure to a single colonized seeder bird. Approximately 1 wk after being housed in a pen with an inoculated seeder bird, all of the other birds became Campylobacter positive. This work emphasizes the importance of preventing all sources of Campylobacter from a flock, because a single colonized bird could infect an entire flock during the growout period.
 
Before any significant progress can be made in altering textural characteristics of a meat product, the basic profile of the meat and the possible alterations in that profile due to processing procedures must be known. A number of papers have been published addressing ways to optimize the textural characteristics of broiler breast meat. Changes in broiler processing procedures and processing time lines have been adopted by processors because of the results of these studies. While the number of breeder hens processed annually is much lower than the number of broilers, adding value to the end product could result in new innovative product forms for this niche market meat. The traditional goal for heavy fowl processors has been to remove the muscles, dice or grind the meat and sell it as an ingredient in other products. In an effort to expand the product forms of breeder hen meat, which is usually assumed to be tough and chewy, this study was designed to profile the texture of the meat based on four postchill (PC) deboning times. Instrumental and sensory profiles of the breast meat from hens were determined. There were significant texture differences in the cooked fillets due to deboning time. Cooked yield for the fillets deboned 24 h PC was lower than for fillets deboned 2 or 8 h PC.
 
Plasma levels of the major metabolic hormones insulin, leptin, triiodothyronine (T 3 ), and insulin-like growth factor-I (IGF-I) in female broiler breeders fed ad libitum (Ad Lib) or maintained in feed restriction from 21 wk of age (Restricted). Plasma samples were collected before photostimulation (prelight, 22 wk), after photostimula- tion (postlight, 24.5 wk), at first egg, and at the plateau of egg production (36.5 wk). All values represent the mean ± SEM of 21 (pre- and postlight) or 40 (first egg and plateau) analyses. Different letters (a–f) designate significant differences ( P < 0.05). Data depicted are from Sun et al. [34]. 
Peptide hormone signals associated with feed intake regulation in birds
Analysis of mRNA expression for the acetyl-coenzyme A carboxylase (ACC) gene in liver from female broiler breeders fed ad libitum (Ad Lib) or maintained in feed restriction from 21 wk of age (Restricted). Also shown are the corresponding relative abdominal fat pad and ovary weights. Values represent the mean ± SEM of 5 de- terminations for ACC gene expression and 21 (pre- and postlight) or 40 (first egg and plateau) for liver and ovary weight analyses. Different letters (a–d) designate significant differences ( P < 0.05). Data depicted are from Rich- ards et al. [33] and Sun et al. [34]. 
Potential adipokines produced by avian adipose tissue
The modern commercial broiler is the product of intensive genetic selection for rapid and efficient growth. An unintended consequence of this selective breeding has been the loss of the ability for self-regulation of feed intake to closely match the requirements for maintenance, growth, and reproduction. Thus, the broiler tends to overconsume feed, resulting in a range of metabolic and health problems related to the development of obesity. These problems progress with age and become a significant impediment to the production of parent stock. To manage this situation, broiler breeder birds must be subjected to severe feed restriction, beginning early in life, to ensure that appropriate BW and composition are achieved at critical phases of the production cycle. This review focuses on the female broiler breeder because this bird requires the most intensive management with respect to feed allocation throughout production to attain BW targets that ensure good livability and efficient egg and chick production. Background information is provided on the cellular and molecular mechanisms that regulate feed intake and energy expenditure in poultry. In addition, several examples are discussed with regard to the endocrine and metabolic consequences of different feeding regimens commonly used in the management of the female breeder during the rearing and egg-laying phases of production.
 
Metabolic, immune, and physical status of chicks can impact the incidence of morbidity and mortality of broilers during the first week of production. Assessments of chick quality are made primarily by subjective observations with few quantitative measurements. Given a better understanding of how broiler breeder hen age and nutrient intake may influence progeny physiology, certain actions can be taken to improve chick quality. This experiment evaluated the effects of broiler breeder age, dietary zinc source, and their interaction on the physiological characteristics of chicks at hatching. Caged broiler breeder hens were provided 1 of 3 diets from hatch through 65 wk of age. All experimental diets consisted of 160 ppm supplemental zinc from inorganic ZnSO4, AvailaZn zinc-amino acid complex (ZnAA) or a mixture of ZnAA and ZnSO4 (ZnAA + ZnSO4, 80 ppm zinc from each). Incubation length, relative organ weights, and carbohydrate status were measured in chicks from hens at 29, 41, 53, and 65 wk of age. The variation in hatch time among eggs set together was not influenced by hen age, but mean incubation length decreased from 29 to 53 wk of age and subsequently increased from 53 to 65 wk. Seasonal temperature changes may have caused confounding effects on incubation length. Chick heart glycogen declined as hens aged, and liver lactate was lowest in progeny from 65-wk-old hens. Relative yolk sac weight and relative heart weight were lowest in progeny from 29-wk-old hens. These data indicate that underdevelopment of supply organs may limit the performance of some chicks from young hens. Supplemental zinc source in breeder hen diets did not influence chick physiology at hatching.
 
In order to create an effective HACCP program, it is important to know the effect of processing steps on microbial populations, including Campylobacter. To test for microbial populations, broiler carcasses were removed from the line in a commercial processing plant at six different sites. Care was taken to follow the same flock through the plant on each visit to eliminate the possibility of a flock effect masking any processing effect measured. On 6 different days, five birds were examined from each site for a total of 30 birds per site (six flocks). Sampling sites included: pre-scald, post-scald/pre-pick, post-pick, post-evisceration (immediately following removal of the viscera), pre-chill/post-final washer, and post-chill. All carcasses were sampled by whole carcass rinse and examined for total aerobes, coliform, generic Escherichia coli and Campylobacter populations. Results are reported as mean log10 CFU/mL of rinse fluid recovered. Overall bacterial populations decreased due to processing. However, coliform, E. coli, and Campylobacter counts, which were all depressed by scalding, increased after the birds moved through the picker.
 
This study evaluated non-destructive sampling methods (i.e., fecal droppings, cecal droppings, and cloacal swabs) to monitor the presence of Campylobacter spp. in broiler chickens on four commercial broiler chicken farms. Samples were taken throughout an 8 wk growout period to assess the presence of the organism during production. During the entire growout period, 45% of 964 fecal droppings, 58% of 284 cecal droppings, and 41% of 786 cloacal swabs presented as positive for Campylobacter spp. This finding indicated that the sampling of cecal droppings was the most sensitive, non-destructive sampling method. This study provides data indicating optimal non-destructive sampling methods for assessing Campylobacter spp. and indicates the typical frequency curve for flock colonization.
 
Categories of data and the percentage of respondents based on region in US A
Percentage of respondents based on size of facility A and region in the US B
Relationship between truck and coop washing stations and size of facility A,B
Percentage of the respondents based on bird size A and water usage B,C Water usage (%)
A survey of commercial broiler processing facilities across the US was conducted to determine overall water use. Seventy-two percent of the respondents reported using city water to process broilers, and 66% reported discharging to city sewers. Over 41% of the responses were from facilities located in the Southeast; however, there was no relationship between location (region of US) of facility and water use or location of facility and water recycling/reuse. Overall, the average water use prior to implementation of the Hazard Analysis and Critical Control Point (HACCP) was 20.6 L/bird, while the current post-HACCP water usage was reported as 26.0 L/bird. Analysis of data also showed a significant relationship between the amount of water used to process each broiler and the size of the broiler being processed. In addition, over 38% of the respondents reported that they recycle water, and a significant relationship was observed between the amount of water recycled and the size of facility. Data from this survey may be used to assist companies interested in establishing water conservation programs or conducting water audits.
 
The tremendous increase in volume of new products containing broiler breast meat has caused many processors to abbreviate the traditional postmortem aging period necessary to ensure ultimate tenderness in the cooked meat. Differences in the tenderness of broiler breast muscle were examined by varying the time prior to deboning breast muscle (0, 1, or 24 hours postchill) and by holding the deboned muscles at refrigerated temperature for various times prior to freezing (0, 12, or 24 hours). Removing breast muscles immediately postchill resulted in the toughest meat. Muscles left on the carcass for 1 hour postchill were less tough than the muscles removed immediately postchill, and the muscles removed after 24 hours were the most tender.
 
Nest-clean and dirty eggs were sampled monthly across the productive period of a commercial broiler breeder flock. Eggshells and membranes were examined for total aerobic bacterial and Enterobacteriaceae counts per egg. Paired nest-clean and dirty eggs were spray sanitized in a two-stage commercial egg sanitizing machine (a chlorine detergent wash followed by a quaternary ammonia sanitizing spray) and tested for bacterial contamination. As the flock aged, numbers of bacteria per nest-clean egg fluctuated without a noticeable trend (from log10 4.1 to 5.3 aerobic bacteria). Bacterial populations were significantly lower on sanitized eggs (log10 0.8 to 3.2 cells total aerobic bacteria and 2 to 5 cells Enterobacteriaceae per egg) regardless of hen age. Those eggs classified as dirty had visible fecal contanmination and higher bacterial numbers than nest-clean eggs (log10 5.9 to 7.6 cells total aerobic bacteria per egg). After sanitization, previously dirty eggs had bacterial populations comparable to those of sanitized nest-clean eggs. When eggs were examined in the hatchery at transfer, sanitized dirty eggs were still microbiologically indistinguishable from sanitized net-clean eggs, though both groups had higher bacterial contamination levels than had been observed in samples taken immediately following sanitization.
 
A technique combining elutriation (air classification) and sieving was developed to remove some of the fiber component of distillers dried grains with solubles (DDGS). Herein, DDGS were sieved into 4 different sizes: large, medium, small, and pan. Fiber was removed from the 3 largest sizes by elutriation via an aspirator, whereby air was blown through the different size categories at a predetermined velocity as the product was falling from the sifter, through the aspirator, and into a collection container. This air movement resulted in a portion of the lighter fiber component being blown into a separate chamber of the respirator and thus into a separate container. The DDGS product obtained by mixing the material that underwent this procedure was called "big DDGS." The pan material, which was in the smallest size category, has a lower fiber concentration and thus underwent no elutriation (pan DDGS). Four different dietary treatments with 12 replicates each were fed to Ross x Ross 308 male broilers from hatch until 42 d of age. A corn- and soybean meal-based diet without DDGS served as the control (treatment 1); treatment 2 had conventional DDGS included at a concentration of 8% (unmodified DDGS); treatment 3 consisted of 8% big DDGS inclusion (partially modified DDGS, PMD), and the fourth treatment consisted of 8% pan DDGS (ED). Final BW was observed to be superior for the birds fed the ED-based diets compared with the BW of those birds fed the control diet and the PMD-based diet. However, contrast analysis showed a significant difference in BW (P = 0.08), with birds fed ED-based diets exhibiting higher BW compared with birds fed unmodified DDGS-based diets. Feed intake was numerically higher for birds fed ED-based diets compared with all other treatments and was significantly greater for birds fed ED-based diets vs. those fed PMD-based diets for the 0- to 42-d period. No other differences were found in bird performance or carcass traits. Results showed some improvement of DDGS via the use of this technology, judging by a marginal improvement in final BW.
 
This study was undertaken to measure the potential for broiler carcass contamination with Campylobacter due to exposure of live birds to a contaminated dump cage. Broilers were obtained from commercial growout houses that had been previously identified as Campylobacter positive or negative by culturing feces. Broilers from a Campylobacter-positive house were placed into a new (never used) five-level commercial dump cage and held for 8 h. When broilers from the positive house were removed and processed, broilers from the Campylobacter-negative house were placed into the same openings of the dump cage. Broilers from the negative house remained in the cage, exposed to the feces of the Campylobacter-positive broilers, for 2, 4, or 6 h before being removed and processed. Carcasses from each group were examined for the presence and number of Campylobacter. After 2, 4, and 6 h of exposure to the contaminated dump cage, more than 50% of defeathered carcasses from previously negative broilers had detectable levels of Campylobacter. These data demonstrate that transportation of Campylobacter-negative broilers in a contaminated container can result in carcass contamination with Campylobacter.
 
Number of positive Campylobacter and Salmonella samples from tissues of 6-wk-old commercial broilers
Previous studies have demonstrated that when Campylobacter or Salmonella were either orally or intracloacally inoculated into day-old broiler chicks, within 1 h, these bacteria moved rapidly to the lymphoid organs. These bacteria were still present 1 wk after inoculation. Two different market-age (6 and 8 wk old) broilers were obtained from 2 commercial poultry operations and brought to the laboratory for analysis. Necropsy was limited to the removal of the spleen, liver and gallbladder (L-GB), and ceca using aseptic techniques. To reduce the possibility of cross-contamination between samples, the spleen and L-GB were aseptically removed before the ceca. Samples were individually bagged, and standard laboratory procedures for Campylobacter and Salmonella were carried out for all samples. Fifty-two 6-wk-old broilers were analyzed, and Campylobacter were found in 19 of 52 L-GB, 19 of 52 spleens, and 26 of 52 ceca. Salmonella were found in 5 of 52 L-GB, 8 of 52 spleen, and 4 of 52 ceca. Eighty 8-wk-old broilers were analyzed, and Campylobacter were found in 3 of 80 L-GB, 5 of 80 spleens, and 19 of 80 ceca. Salmonella were found in 41 of 80 L-GB, 38 of 80 spleens, and 52 of 80 ceca. The internal organs of the younger birds were more heavily contaminated with Campylobacter, whereas Salmonella was the predominant organism isolated in the older birds. All Campylobacter isolates were found to be Campylobacter jejuni. The predominant Salmonella serotype was Salmonella Typhimurium; however, 7 other serotypes were found. Overall, C. jejuni was found in 22 of 132 L-GB, 24 of 132 spleen, and 45 of 132 ceca, whereas Salmonella serovars were isolated from 46 of 132 L-GB, 46 of 132 spleen, and 56 of 132 ceca. There is no doubt that these bacteria are naturally present in these organs. The significance of these reservoirs in the internal organs of commercial broilers is yet to be determined but could play a role in the microbiology of the intestinal tract and hence the final food product.
 
Mucosal competitive exclusion (MCE) cultures generated from the mucosal scrapings of healthy adult turkeys were administered to commercial turkey poults. MCE-treated poults were placed on tom and hen farms with paired untreated control poults in adjacent houses. After 6 wk in the brood house, cecal droppings from control and treated flocks were collected and analyzed for the presence of salmonellae. Salmonellae were detected in 14 of 30 cecal droppings (47%) from control flocks and from only 1 of 30 (3.3%) droppings from the treated poults. This study demonstrated that mucosal competitive exclusion could be used to effectively control salmonellae in a commercial field trial of young turkey flocks.
 
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Pierre Buttin
Julia J Dibner
  • Novus International, Inc.
Yumin Bao
  • redox, australia
Mingan Choct
  • University of New England (Australia)
Paul Iji
  • Fiji National University