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The present study was conducted to evaluate the protective effect of dietary boric acid supplementation on the development of incidence and severity of footpad dermatitis (FPD) in broiler chickens subjected to normal or high stocking densities (NSD or HSD). A total of 576 1-day-old ROSS 308 broiler chickens were randomly allocated to 4 treatments (8 replicate pens per treatment) in a 2 x 2 factorial arrangement of dietary boric acid (0 and 60 mg/kg) and stocking density (NSD 14 birds/m(2) and HSD 22 birds/m(2)). Basal diets were formulated for starter, grower, and finisher phases. Growth performance, litter quality (litter pH, moisture, temperature, and NH3 volatilization), serum and litter boron levels, and incidence and severity of FPD were recorded. The HSD affected the body weight gain and feed intake of broiler chickens during all phases and 0 to 42 (P < 0.05), whereas feed conversion ratio (FCR) was poor at 0 to 21 days only. Dietary boric acid had no effect on the growth performance of broiler chickens. Litter pH, moisture, and NH3 volatilization were higher in broiler chickens subjected to HSD (P < 0.05). Thus, the incidence and severity of FPD increased in response to HSD (P < 0.05). Dietary boric acid reduced the litter pH and NH3 volatilization on day 42 of experiment (P < 0.05). However, dietary boric acid supplementation had no effect on the incidence and severity of FPD. Boric acid supplementation in broiler diets increased the serum and litter boron levels at day 42 in broiler chickens subjected to NSD or HSD (P < 0.05). In conclusion, HSD resulted in poor growth performance, litter quality, and greater incidence and severity of FPD in broiler chickens. Dietary boric acid was ineffective against FPD in broiler chickens although it improved the litter quality by lowering the litter pH and NH3 volatilization.

Two experiments (Exp) were conducted to determine if reductions in the incidence and severity of wooden breast (WB) and white striping (WS) may be obtained by reducing dietary nutrient density. In each Exp, Yield Plus × Ross 708 male broiler chicks were placed into 63 pens (22 birds/pen). All birds received an identical prestarter diet until 7 d of age, after which time each pen was randomly assigned to 1 of the following 7 dietary treatments (TRT) for the starter (8 to 14 d), grower (15 to 24 d), finisher 1 (Exp 1: 26 to 35 d; Exp 2: 26 to 42 d), and withdrawal (Exp 2: 43 to 48 d) phases: 1) 100% of primary breeder recommendations for digestible amino acid and metabolizable energy density throughout Exp; 2) 95% of TRT 1 until 14 d of age, then as TRT 1; 3) 95% of TRT 1 until 24 d of age, then as TRT 1; 4) 95% of TRT 1 throughout Exp; 5) 90% of TRT 1 until 14 d of age, then as TRT 1; 6) 90% of TRT 1 until 24 d of age, then as TRT 1; 7) 90% of TRT 1 throughout Exp. At 36 d (Exp 1) and 49 d (Exp 2), 18 birds per pen were processed and evaluated for WS and WB. In Exp 1, reduced dietary density in the starter phase (TRT 2 and TRT 5) resulted in increased (P ≤ 0.05) incidences of severe WB (32.9% and 34.7%) relative to TRT 1 (18.2%). In Exp 2, broilers assigned to TRT 7 had reduced (P

This study was conducted to evaluate the effects of dietary lycopene supplementation on growth performance, antioxidant status, and muscle nuclear transcription factor [Kelch like-ECH-associated protein 1 (Keap1) and (erythroid-derived 2)-like 2 (Nrf2)] expressions in broiler chickens exposed to heat stress (HS). A total of 180 one-day-old male broiler chicks (Ross 308) were assigned randomly to one of 2×3 factorially arranged treatments: two housing temperatures (22°C for 24 h/d; thermoneutral, TN or 34°C for 8 h/d HS) and three dietary lycopene levels (0, 200, or 400 mg/kg). Each treatment consisted of three replicates of 10 birds. Birds were reared to 42 d of age. Heat stress caused reductions in feed intake and weight gain by 12.2 and 20.7% and increased feed efficiency by 10.8% (P

Quantitative control of nutrient intake may decrease the incidence of wooden breast (WB) and white striping (WS) myopathies with some impairment of live performance. Two experiments (Exp) utilizing Yield Plus × Ross 708 male broilers were conducted to determine if a reduction in myopathies may be obtained through a qualitative approach by reducing digestible lysine (dLys) density. All birds received an identical starter diet until 11 d of age. In Exp 1 (63 pens; 22 birds/pen), each pen was then randomly assigned to 1 of the following 7 dietary treatments (TRT) for a 47 d production period. Seven dietary treatments were provided for the grower 1 (G1; 12 to 18 d of age) and grower 2 (G2; 19 to 26 d of age) phases: 1) 100% of primary breeder recommendations for dLys throughout Exp; 2) 85% of TRT 1 dLys for G1; 3) 85% of TRT 1 dLys for G2; 4) 85% of TRT 1 dLys for G1 and G2; 5) 75% of TRT 1 dLys for G1; 6) 75% of TRT 1 dLys for G2; 7) 75% of TRT 1 for G1 and G2. In Exp 2 (24 pens; 30 birds/pen), birds were randomly assigned to 1 of the following 4 dietary TRT (Table 2) during a 61 d production period. Four dietary treatments were provided for the grower (G; 12 to 28 d) and finisher 1 (F1; 29 to 40 d of age) phases: 1) 100% of primary breeder recommendations for dLys 2) 85% of TRT 1 dLys for G; 3) 85% of TRT 1 dLys for F1; 4) 85% of TRT 1 dLys for G and F1; thereafter, birds received common finisher 1 (Exp 1: 27 to 42 d of age), finisher 2 (Exp 2: 41 to 48 d of age) and withdrawal (Exp 1: 43 to 47 d of age; Exp 2: 49 to 61 d of age) diets. Ideal amino acid ratios were not maintained in reduced dLys diets in either Exp. At 48 (Exp 1; 18 birds/pen) and 62 (Exp 2; 30 birds/pen) d of age, selected birds were processed and fillets were visually scored for WB and WS. No differences (P > 0.05) in cumulative live performance responses between TRT 1 and the remaining TRT were observed in either Exp. In Exp 1, the incidence of severe WB (20.8%) and WS (42.3%) at 48 d of age among birds receiving TRT 7 was reduced (P < 0.01) compared with TRT 1 (WB: 36.6%; WS: 64.3%), at the expense of reduced (P = 0.003) breast weights and yield. In Exp 2, the incidence of severe WB (18.8%) and WS (17.8%) at 62 d of age for birds receiving TRT 4 was reduced (P < 0.05) compared with TRT 1 (WB: 39.3%; WS: 38.3%), without any detrimental effects on processing characteristics. These results indicate that altering dietary dLys during critical periods of the growth trajectory may be a viable strategy for reducing the incidence and severity of WB and WS.

Two experiments (Exp) were conducted to determine if reductions in the incidence and severity of wooden breast (WB) and white striping (WS) may be obtained by reducing dietary nutrient density. In each Exp, Yield Plus × Ross 708 male broiler chicks were placed into 63 pens (22 birds/pen). All birds received an identical prestarter diet until 7 d of age, after which time each pen was randomly assigned to 1 of the following 7 dietary treatments (TRT) for the starter (8 to 14 d), grower (15 to 24 d), finisher 1 (Exp 1: 26 to 35 d; Exp 2: 26 to 42 d), and withdrawal (Exp 2: 43 to 48 d) phases: 1) 100% of primary breeder recommendations for digestible amino acid and metabolizable energy density throughout Exp; 2) 95% of TRT 1 until 14 d of age, then as TRT 1; 3) 95% of TRT 1 until 24 d of age, then as TRT 1; 4) 95% of TRT 1 throughout Exp; 5) 90% of TRT 1 until 14 d of age, then as TRT 1; 6) 90% of TRT 1 until 24 d of age, then as TRT 1; 7) 90% of TRT 1 throughout Exp. At 36 d (Exp 1) and 49 d (Exp 2), 18 birds per pen were processed and evaluated for WS and WB. In Exp 1, reduced dietary density in the starter phase (TRT 2 and TRT 5) resulted in increased (P ≤ 0.05) incidences of severe WB (32.9% and 34.7%) relative to TRT 1 (18.2%). In Exp 2, broilers assigned to TRT 7 had reduced (P 0.01) incidences of severe WB (20.8%) and WS (42.3%) relative to the control (WB: 36.5%; WS: 64.5%). In both Exp, plasma creatine kinase and lactate dehydrogenase increased (P ≤ 0.05) with increasing scores for WB and WS. Reducing dietary nutrient density from 8 to 14 d may exacerbate fillet myopathies in broilers reared to 35 d of age. Although reducing dietary energy and amino acid density to 90% of recommendations from 1 to 48 d reduced the severity of myopathies, these reductions occurred with compromises in live performance. Altogether, these results indicated that concurrent manipulation of dietary amino acid and energy density is not a viable practical solution for breast myopathies.

This study was conducted to evaluate the efficacy of a scald additive, RP scald, to reduce Salmonella Typhimurium (ST) levels on inoculated poultry carcasses. The RP scald (contains sodium hydroxide) in a 1% solution has a pH of 11.0, which may reduce bacteria levels on carcasses. In this study, 600 broilers (Ross 708 straight run, 6 wk of age) with 300 broilers in each of 2 experimental trials were divided into 4 scald treatments (inoculated with ST) and 2 noninoculated groups. The treatment groups included 4 scald treatments (n = 50 per experimental group per trial): soft scald (SS; 50 degrees C for 90 s), soft scald with 1.0% added RP scald (SSRP), hard scald (56.6 degrees C for 45 s; HS), and hard scald with 1.0% added RP scald. The noninoculated groups (n = 50 per group per trial) are represented by SS0 and HS0. After defeathering, carcass rinses were collected for ST detection. Results indicated that inoculated broilers from hard scald with 1.0% added RP scald had the lowest Salmonella recovery, whereas carcasses from the SS treatment with no RP additive had the highest ST recovery. In trial 1, the SSRP was more effective in reducing ST than HS alone; however, this trend was not consistent. In trial 2, HS alone was more effective in ST reduction than SSRP. Within each scald temperature, the addition of RP scald increased ST reduction; therefore, RP scald may be effective in reducing ST on broiler carcasses in poultry scalder applications, particularly when hard scald temperatures are used.

This study investigated effects of light intensity and photoperiod on live and processing performance and physiological stress of broilers. One hundred broilers were housed in each of 12 rooms, provided 23L:1D with 3 footcandles (FC) of intensity to 8 d, and then subjected to the following treatments in a 2 x 2 factorial arrangement: either 1 FC (1FC) or 0.1 FC (0.1FC) from 8 to 49 d and either 23L:1D from 8 to 49 d (23L) or 18L:6D from 8 to 43 d followed by 23L:1D from 43 to 49 d (18L). At 40 d, blood samples were drawn and heterophil:lymphocyte ratios determined. At 49 d, 16 birds from each room were processed to determine weights and yields. There were interaction effects on BW from 29 to 49 d. At 29 d, BW was reduced by either 18L or 0.1FC treatments. At 43 d, BW was greatest in 1FC-23L, reduced in 1FC-18L and 0.1FC-23L, and intermediate in the 0.1FC-18L treatment. At 49 d, BW of 1FC-23L and 0.1FC-18L were similar and greater than those of 1FC-18L and 0.1FC-23L treatments. Feed consumption was reduced by 18L treatment from 15 to 29 d and the 0.1FC treatment at 15 d. Feed conversion and mortality were not affected by treatments. The 0.1FC treatment decreased uniformity at 15 d. Heterophil:lymphocyte ratios averaged about 0.45 and were not affected by treatments. Carcass yield and tender weight were reduced by the 0.1FC treatment, whereas whole breast yield was reduced by the 18L treatment. There were interaction effects on whole breast weight and fillet weight and yield, which were reduced by either the 18L or 0.1FC treatments. These results indicate that although the combination of 18L:6D and 0.1FC may result in broiler live performance comparable to that achieved with 23L:1D and 1FC, and no combination of the photoperiods and intensities tested caused physiological stress, breast meat is generally reduced by either 18L:6D or 0.1FC.

Poultry processing plants in the United States were surveyed on their current Campylobacter and Salmonella control practices. Following surveys, data were collected to develop a baseline for prevalence rates of Salmonella and Campylobacter; then changes in practices were implemented and evaluated for improvements in pathogen control. Surveys were sent to the plant Quality Assurance managers to determine production levels, antimicrobial interventions, and current pathogen testing practices. Initial sampling was performed at 6 plants with similar production volumes, at sites that included carcass samples before any pre-evisceration intervention, after exiting the inside-outside bird washer (IOBW), after exiting the pre-chiller, after exiting the primary chiller, and after exiting any post-chill intervention, as well as a water sample from each scalder, pre-chiller, primary chiller, and post-chill dip tank or finishing chiller. Enumerations and enrichments were performed for Campylobacter and Salmonella. Following the baseline sampling, changes in practices were suggested for each plant and a second sampling was conducted to determine their effectiveness. Results demonstrated that peracetic acid (PAA) was the most effective (P0.05) antimicrobial currently in use. The use of a post-chill antimicrobial immersion tank and/or use of a cetylpyridinium chloride (CPC) spray cabinet also displayed a further reduction in microbial levels (P0.05) when the primary chiller was not sufficient (P0.05). Microbial buildup in the immersion tanks demonstrates the need for effective cleaning, sanitation practices, and chiller maintenance to reduce contamination of poultry with Campylobacter and Salmonella.

This is the first report providing estimates of the genetic basis of breast muscle myopathies (BMM) and their relationship with growth and yield in broiler chickens. In addition, this paper addresses the hypothesis that genetic selection for increase breast yield has contributed to the onset of BMM. Data were analyzed from ongoing recording of BMM within the Aviagen breeding program. This study focused on three BMM: deep pectoral myopathy (DPM; binary trait), white striping (WS; 4 categories) and wooden breast (WB; 3 categories). Data from two purebred commercial broiler lines (A and B) were utilized providing greater than 40,000 meat quality records per line. The difference in selection history between these two lines has resulted in contrasting breast yield (BY): 29% for Line A and 21% for Line B. Data were analyzed to estimate genetic parameters using a multivariate animal model including six traits: body weight (BW), processing body weight (PW), BY, DPM, WB, and WS, in addition to the appropriate fixed effects and permanent environmental effect of the dam. Results indicate similar patterns of heritability and genetic correlations for the two lines. Heritabilities (h2) of BW, PW and BY ranged from 0.271–0.418; for DPM and WB h2

The Poultry Science Association (PSA) leadership has created its first comprehensive 5-year strategic plan (2006 to 2010) as a guide to the organization's growth and development. As societal concerns about animal agriculture increase and as changes in the poultry industry and in universities reduce the numbers of poultry scientists and thus membership in PSA, it became apparent that, to maintain relevance, the PSA needed to undertake a more rigorous and comprehensive review of its assets, areas of weakness, and reasons for being. The strategic planning process provided the lens for organizational analysis and planning. Our new mission for the PSA is to be a global scientific society dedicated to discovery and dissemination of knowledge, generated by poultry research that enhances human and animal health and well-being and provides for the ethical, sustainable production of food. The Association's vision is to be a preeminent global organization of poultry scientists and industry leaders, firmly grounded in scientific endeavors related to the biology and production of poultry. Increased membership diversity will be pursued by recruiting people of varied geographic, gender, cultural, and scientific backgrounds—including health and medicine—leading to a diverse leadership. The PSA will serve as the clearinghouse for poultry science information and provide through its Foundation significant financial support to students and young scientists engaged in poultry science research, teaching, and outreach education. The PSA, in partnership with the Federation of Animal Science Societies (FASS), will be a highly credible, well-respected, powerful force that is able to influence policy makers at governmental levels for the benefit of animal agriculture by delivering sound scientific information. The strategic plan highlights strategic directions to be implemented as well as assessment of progress. It will take the vision, energy, and dedication of PSA leaders and members to ensure that the strategic plan is well implemented, monitored, and altered appropriately, keeping it a living plan of action.

This study was performed to evaluate breast muscle development in chicken genotypes divergently selected for muscularity. In the first experiment, 2 commercial broiler lines (a high breast yield, HBY, and a normal breast yield broiler strain-cross, NBY) and a Leghorn line were grown up to 35 d to evaluate BW, breast weight, and breast yield. At 7 and 21 d of age, pectoralis muscle was used to estimate myofiber density (MFD, number of myofibers per mm2) and total apparent myofiber number (MFN). In the second experiment, the ontogeny of myostatin was determined from broiler- and Leghorn-type chick embryos, at embryonic days 1 to 20 (E1 to E20), using reverse transcription (RT)-PCR. As expected, the Leghorn line had lower BW, breast weight, and breast yield than broiler lines. The HBY line showed higher breast yield at all ages evaluated, but lower BW at 21 and 35 d than the NBY line. The Leghorn line had 45% higher MFD than broilers, which indicates an increased cross-sectional area of the myofibers in broiler lines. No MFD difference was observed between the broiler strains (P > 0.05). The myofiber number of broilers was more than twice that of Leghorns and HBY had 10% higher MFN than the NBY line. Myofiber number was correlated to BW (r = 0.58), breast weight (r = 0.58), and breast yield (r = 0.69). Conversely, MFD showed negative correlation with BW, breast weight, and breast yield (r = -0.85, -0.83, and -0.88, respectively). No effect of genotype or interaction between genotype and embryonic age was observed for myostatin expression. This study showed that broilers have higher MFN in the breast muscles than Leghorn-type chickens, and that high breast yield of broiler strains may be due to increased MFN. Higher muscularity of broilers, as compared with Leghorns, was not attributed to lower expression of myostatin during embryonic development.

Genetic and gender-related variations in breast muscle yield of broiler chickens may be attributed to differences in number and size of muscle cells (myofibers). In this study, male and female broilers from eight commercial strain crosses (SC) were compared for body and breast muscle weight with adjustment of the Gompertz function. Additionally, breast fillet dimensions (length, width, and depth) and myofiber density (myofiber number/area; MFD) were assessed. Live weight and breast muscle development was determined to 56 d of age at weekly intervals. MFD was assessed at 8 d of age. As expected, SC differed in BW, breast weight and yield, and breast fillet dimensions and had variations in growth curves. Maximal growth rate for breast weight was reached approximately 4 d after that of BW. Males and females showed different growth curves, with males having slower growth rate maturity parameter and reaching the maximal growth rate later than females for BW and breast weight. Breast depth was the breast measure with highest positive correlation to breast yield. SC differences could not be explained by MFD, but males had higher MFD density than females. The possible relationship of the MFD observations to total myofiber number is discussed.

This paper provides an overview of the electrical stunning systems and their implementation in modern-day broiler slaughter plants. The application of low voltage electrical stunning systems in the U.S. is reviewed and contrasted with European experiences within the context of differing slaughter technologies, practices, and regulatory constraints. Finally, the impact of electrical stunning on traditional carcass and meat quality attributes of broilers is examined.

Two experiments (EXP), utilizing the skin attachment model (SAM), were conducted to determine the bactericidal activity of six potential carcass disinfectants [EXP 1: 20, 400, and 800 ppm sodium hypochlorite; EXP 2: 5% acetic acid (AA), 8% trisodium phosphate (TSP), and 1% sodium metabisulfite (SS)] during simulated scalder (50 C for 2 min), chiller (0 C for 60 min), or post-process dip (23 C for 15 s) application. Efficacies of treatments were determined against populations of Salmonella typhimurium that were "loosely" or "firmly" attached to chicken breast skin (10 cm diameter). For comparison, activity of the six disinfectants was also determined against S. typhimurium in aqueous suspension. All disinfectants except SS reduced numbers of freely suspended S. typhimurium byor = 4.5 log10 cfu/mL. The sodium metabisulfite did not reduce populations of salmonellae. In both EXP, there were disinfectant by application interactions (P0.05) on activity against loosely and firmly attached cells. Sodium hypochlorite at 20 ppm had little activity regardless of application, whereas higher levels were more effective (P0.001), particularly in the chiller application, in which loosely and firmly attached populations were reduced by 2.3 to 2.5 and 1.3 to 1.9 log10 cfu per skin, respectively. In EXP 2, SS showed no activity regardless of application. Trisodium phosphate was similarly effective (reduction by 1.2 to 1.8 log10 cfu per skin) in all applications (P0.05). In contrast, AA activity was affected by the application method (P0.05). Against loosely attached cells, AA was most effective in the chiller application (2.5 log10 reduction), whereas against firmly attached cells, AA was effective only in the scalder application (2.0 log10 reduction). Attachment of S. typhimurium to poultry skin apparently increased the ability of the bacteria to resist various disinfectants, and efficacy was influenced by extent of attachment of bacteria to skin and method of disinfectant application.

Six-week-old broilers were compared in yield and weep loss when stunned using either 25 or 125 mA current followed by slush-ice chilling where resultant carcasses were either held static for 4 h or subjected to 45 m of tumbling. Treatments were factorially arranged among the populations of 32 pens (24 birds per pen) that had been reared under common conditions. Tumbling increased chill water uptake, abdominal fat content, and yield of whole carcasses, whereas no differences occurred as a result of the stunning treatments. Carcasses were separated into a nine-piece cut immediately after chilling. All parts lost weight from weepage during the subsequent 24 h, and weep from total parts was greater when carcasses had been tumbled than held static. Keel portion breasts and drumsticks continued a weight advantage from water uptake with tumble chilling, but wings, thighs, and split breast lost this additional water and were similar to those respective parts static chilled. High stunning current led to an increased amount of keel portion breast, regardless of chilling treatment, with subsequent weep not being affected. Alterations in yield that occur because of chilling procedure are substantial and not equivalent among parts, whereas stunning has little impact and is focused on the breast.

Live performance and skin characteristics of male and female broilers were evaluated under four coccidiostat feed additive programs. Treatments consisted of halofuginone (H) and salinomycin (S), fed either continuously (HH and SS) or in rotational programs (HS and SH) during the starter (1 to 21 d) and grower (22 to 35 d) periods, respectively. An unmedicated withdrawal feed was provided from 36 to 42 d of age. Body weights, feed efficiency, and mortality (by pen) were determined, in addition to skin puncture strength measurements taken at Days 21, 35, and 42 on five birds per pen. At 43 d of age, all birds were processed and individually graded for skin defects. There were no treatment by sex interactions for any variable measured. Male body weights, feed efficiency, and total mortality exceeded those of females (P < .05). Skin puncture strength was reduced at 21 d in the HH and HS groups, at 35 d in the HH and SH groups, and at 42 d in the HH, HS, and SH groups. Thigh sores and scratches were higher for the HH group (P < .05), and thigh skin tears were higher for the HH and HS groups (P < .01). Males had more swollen hock joints and breast blisters than females (P < .001). Females had more thigh skin tears (P < .01) and broken wings (P < .001) than males. Results of the present study demonstrated that halofuginone affected skin strength of broilers, especially when used continuously or only in the starter feed (1 to 21 d).

Live performance and carcass quality of female broilers were evaluated under four coccidiostat programs (CP) and two feed treatments. The CP consisted of halofuginone (H) and salinomycin (S), fed either continuously (HH and SS) or in rotational programs (HS and SH), during the starter (1 to 21 d) and grower (22 to 35 d) periods, respectively. All groups received an unmedicated withdrawal feed from 36 to 42 d. Feed treatments consisted of a control and a fortified diet high in proline and supplemented with additional ascorbic acid and zinc (50 birds per pen; 4 pens per feed; 8 pens per CP). In addition to live performance and skin puncture strength, carcass quality attributes following processing (at 43 d of age) were assessed. No CP by feed interactions were detected for any of the variables measured. The CP treatments did not differ for live performance. Birds on fortified feed were heavier at 21 d (P < .001) and had an improved feed conversion at 42 d (P < .05). Skin puncture strength was significantly reduced for the birds fed H, either in continuous (HH) or rotational programs (HS and SH). Skin sores-scratches and tears were lowest for the SS and SH groups. The HH treatment resulted in fewer grade A carcasses (P < .001). Halofuginone, when fed continuously or in the starter feed, affected carcass quality of broilers. Higher dietary proline or supplementation with ascorbic acid and zinc did not appear to alleviate the effects of halofuginone on skin quality.

The purpose of this study was to compare the effectiveness of restricted or increasing light with conventional near continuous light for improving performance of male broilers. Fifty day-old male broiler chicks (Cobb × Arbor Acres) were placed in each of 16 light-controlled chambers. Four chambers were randomly assigned to each of four light treatments: 1) 23 h light (L):l h dark (D) (23L); 2) 16L:8D (16L); 3) 14L:10D (14L); or 4) 23L:1D from Days 1 to 3, 6L:18D from Days 4 to 13, 10L:14D from Days 14 to 20, 14L:10D from Days 21 to 27, 18L:6D from Days 28 to 34, and 23L:1D from 35 to 49 days of age (INC). Ten birds per chamber were randomly selected for processing at 49 days of age. Treatments 16L, 14L, and INC had lower mortality than Treatment 23L (3.0, 3.5, and 3.5 versus 9%, respectively). There was a significant overall treatment effect for BW with Treatment 23L having greatest BW from 7 to 42 days; however, BW was not significantly (P ≥ .05) different at 48 days (2,924, 2,912, 2,850, and 2,884 g for Treatments 23L, 16L, 14L, and INC, respectively). Tender yield (per lean carcass weight) was greater in Treatment 23L than in Treatment 14L (4.64 versus 4.42%, respectively), and a converse relationship existed for drumstick yield (14.44 versus 15.07%, respectively). Fillet yield was greater in Treatment 23L than in Treatments 16L, 14L, and INC (20.06 versus 18.86, 18.94, and 19.04%, respectively). Restricted light programs (14L and 16L) were as efficacious as increasing light (INC) for improving broiler livability but had a similar negative influence on breast meat yield.

A dietary regimen employing the CP, ME, and essential amino acid (EAA) levels advocated by National Research Council in 1984 for broilers from 0 to 3 and 3 to 6 wk was compared with one in which only the CP was reduced from 23 to 20 and 20 to 17%, respectively. Corn, soybean meal, corn gluten meal, and fish meal analog were used together with the commercially available free EAA in least-cost formulation. Males and females from Peterson × Arbor Acres and Ross × Arbor Acres were grown in floor pens simulating commercial conditions. Live body weights were unaffected by dietary CP level throughout production; however, feed conversion was increased during the 3- to 6-wk interval when the CP was reduced. Reducing the dietary CP substantially decreased N content of the litter. Processing the birds revealed an increase of depot fat in the abdominal cavity when low CP had been fed. Removal of this fat depot led to a lower chilled carcass weight than when the 1984 National Research Council levels were employed. Cutting the carcass into fast-food portions indicated that reduced CP also decreased the proportion of split breast with back using an eight-piece cut and keel portion of the breast based on a nine-piece cut whereas thigh with split back increased. Both sexes and each strain responded similarly. Although reducing dietary CP reduces N content and, therefore, pollution potential of the resulting litter, adverse effects occur in live performance and the yield of breast pieces with two fast-food cutting procedures.

The purpose of the present study was to compare a restricted (R) lighting program [16 h light (L):8 h dark (D)] with a standard extended (E) lighting schedule (23L:1D) for broilers. Experiment 1 was carried out during March and April (mean temperature of 23.3 C). Light treatments were 1) E; 2) R; 3) 16L:8D Days 1 to 21 and 23L:1D thereafter to 49 days (R3E); and 4) 16L:8D Days 1 to 14 and 23L:1D thereafter to 49 days (R2E). Treatments were factorially arranged with two strain crosses [Indian River × Arbor Acres (IA) and Peterson × Arbor Acres (PA)]. Experiment 2 was carried out during the summer (mean temperature of 27.0 C). Light Treatments E and R were factorially arranged with two strain crosses [Cobb × Arbor Acres (CA) and PA]. In Experiment 1, BW of Cross PA was greater than BW of Cross IA at 1, 14, 35, and 49 days of age. The percentage of birds with breast blisters was greater in Cross PA than IA. The incidence of broken clavicles was lower in Treatments R and R3E than in Treatments E or R2E. In Experiment 2, Treatment E had greater BW than R from 7 to 42 days of age, and BW of Cross CA was greater than that of PA from 1 to 48 days. Yield (percentage of lean carcass weight) of breast meat at 49 days of age was higher for Treatment E than R, and the percentage of birds with breast blisters was greater in Treatment R than E. In both experiments, Cross PA had lower breast meat yield (percentage of lean carcass weight) than the other strain crosses.

The purpose of the present experiment was to examine possible interactions of strain cross and age with photoschedule for broiler performance and carcass yield. Day-old male broiler chicks from strain crosses of either Peterson × Arbor Acres (PA) or Ross × Arbor Acres (RA) were placed in light-controlled chambers (5.6 lx) with either 23 h light (L):1 h dark (D) from 1 to 56 days (Treatment E) or 6L:18D from 1 to 14 days and 1L:3D repeated from 15 to 56 days of age (Treatment BI). There were age by light treatment and age by strain cross interactions for BW; Treatment E had greater BW than Treatment BI from 7 to 42 days, and the PA cross BW was greater than the RA cross BW from 1 to 42 days of age. Cumulative feed efficiency was improved by Treatment BI compared with Treatment E up to 49 days. There were no differences among main effects for mortality, and the incidence of leg problems increased with age. Fillet and tender yields (per lean carcass weight) were higher for Treatment E than BI and opposite responses were seen for drumstick and thigh yields. The RA cross showed higher fillet and tender yields than the PA cross and the opposite relationship was found for drumstick and wing yields.

The suitability of recycled paper chips (RPC), formed by completely reprocessing waste newspaper, as litter material for rearing broilers was investigated in two successive trials. In Trial 1, broilers were reared in pens prepared with a 9-cm layer of either unused RPC or pine shavings (PS). In Trial 2, broilers were reared in pens prepared by adding 3 cm of clean RPC or PS to used litter of the same type remaining from Trial 1. Mortality, BW, feed consumption and conversion, carcass yield, and incidences of breast blisters and leg abnormalities were not influenced by litter treatments. Litter moisture was greater in RPC during Week 3 of Trial 1, but did not differ between treatments at other times during either trial. Litter caking was greater in RPC throughout Trial 1, but did not differ between treatments during Trial 2. Populations of aerobic, psychrotrophic, and coliform bacteria, and fungi (yeasts and molds) in the two litter types did not differ during the rearing period of either trial. Populations of aerobic bacteria and fungi were greater in unused PS, and fungi populations were greater in used PS prior to initiation of Trial 2. Populations of psychrotrophic bacteria were greater in used PS 6 days after bird removal in Trial 2. Generally, RPC are comparable to PS and have potential as an alternative litter material for rearing broilers.

The purpose of the present study was to measure performance and carcass yield from broilers maintained on photoschedules that may influence incidence of leg disorders. Day-old male broilers were placed on litter floors of light-controlled chambers. Four chambers were randomly assigned to each of four light treatments: 1) 23 h light (L): 1 h dark (D) from 1 to 56 days of age (designated extended, E); 2) 1L:3D from 1 to 56 days (intermittent, I); 3) 6L:18D from 1 to 14 days and 1L.:3D) from 15 to 56 days (brief-I, BI): and 4) 6L:18D from 1 to 14 days and 23L:1D from 15 to 56 days (brief-E, BE). Mean (± SEM) light intensity was 5.4 ± .26 lx for all light treatments. At 13, 21, and 42 days of age, Treatments BI and BE had lower BW than Treatment E. The percentage of birds with leg abnormalities among treatments was greater at 56 days than at 42 days. The BI birds had significantly fewer leg abnormalities than E birds. There was an age by treatment interaction for the frequency of tibial dyschondroplasia (TD), with BI showing better recovery from TD at 56 days than other treatments. At 42 days of age, split breast yield (percentage of BW) was greater in E than I and breast yield (percentage of lean carcass) was greater in E and BI compared with I. At 56 days of age, yield (percentage of BW) of tenders was lower in I and BI compared with E and BE. Yield of wings (percentage of lean carcass) was greater in BI than BE, and yield of thighs was greater in BI than E.

Experimentation was conducted to evaluate the effect of improved pellet quality from using a calcium lignosulfonate (CaLS) binder on broilers reared sexes-separate and combined. Three thousand day-old chicks of two commercial strain crosses were housed in 60 floor pens (five replicate pens per treatment) and reared under summer conditions. The CaLS (12.5 kg/tonne) was added to a corn, soybean meal, and corn gluten meal diet and fed from 3 wk to marketing. Use of the binder led to a 56% improvement (P .05). Feed consumption and feed:gain ratio of the birds were increased (P .05) even though final body weight (P

This study investigated the effects of different light intensities provided via an increasing photoperiod program on broiler live performance and processing characteristics. A total of 1,080 male broilers were evenly distributed in 12 rooms. Six rooms were subjected to intensities of either 15 footcandles (FC) from 1 to 51 d (Bright), or 0.5 FC from 1 to 9 d and 0.1 FC from 9 to 51 d (Dim). Both intensity treatments were provided in an increasing photoperiod program (23L:1D, 1 to 9 d; 12L:12D, 9 to 16 d; 14L:10D, 16 to 23 d; 17L:7D, 23 to 30 d; 20L:4D, 30 to 37 d; and 23L:1D, 37 to 51 d). Feed consumption and BW were determined, and feed conversions were calculated approximately weekly. Mortalities were necropsied and recorded daily. At 51 d, 30 birds from each room were processed and cut up to determine weights and yields. Beginning at 23 and 30 d, respectively, BW and feed consumption were greater in the Dim treatment. At 51 d, Dim treatment BW was 4.7% greater and feed consumption was 3.9% greater. Feed conversion, metabolic and total mortality, and BW uniformity were not influenced by light intensity. Weights of lean carcass, total breast, fillets, tenders, and legs were from 4.9 to 6.2% greater in the Dim treatment, which was proportional to the BW difference and resulted in similar yields of these parts. However, wings were 9.9% heavier in the Dim treatment, which resulted in greater wing yield. Equal fat pad weights resulted in reduced fat pad yield in the Dim treatment. These results indicate that BW, feed consumption, and most parts weights were increased proportionally by providing 0.1 vs. 15 FC of light intensity via an increasing photoperiod program, and that only the yields of minor parts were affected by intensity.

A feed based on com, soybean meal, and sesame meal containing .85% lysine was supplemented with L-lysine HCl to provide .95 and 1.05% of total lysine. Each lysine level was given to broilers from 28 to 42 days of age in which the sexes were reared separately. No differences occurred in BW because of lysine, but feed conversion decreased as the lysine level increased. The holding loss prior to slaughter was greater with the birds that had received .95% lysine versus those that had received .85 and 1.05% lysine, respectively; however, no effects were detected on the chilled-carcass yield after processing. The extent of carcass finish increased as the lysine decreased. The fat content of the whole chilled carcass increased along with finish, while protein and ash were to the reverse. The percentage of fat in the skin and in the thigh meat were altered in parallel with the whole carcass, but the breast meat was unaffected. Cutting sample carcasses into commercial parts revealed that the proportions of breast and thigh increased with lysine at the expense of back both on a raw and a cooked basis. The cooked meat from the breast, wings, and back increased, the skin decreased. Both sexes responded similarly to lysine.

Two 4 x 2 factorial experiments were designed to test the effects of four diets, differing in anticoccidial programs and roxarsone (3-nitro-4-hydroxyphenylarsonic acid) content, and two lighting programs on the incidence of leg abnormalities in 56-d-old male and female broiler chickens. The four diets were: A) basal diet + salinomycin (60.0 g/ton); B) basal diet + salinomycin (60.0 g/ton) + roxarsone (45.4 g/ton); C) basal diet + roxarsone (45.4 g/ton) + live coccidial vaccine; and D) basal diet + live coccidial vaccine. The light treatments were: 1) restricted (R) [18 h light (L): 6 h dark (D)] and 2) standard (S) [23L:1D]. The respective experiments were conducted during winter (Experiment 1, November to January) and summer (Experiment 2, June to August) growing conditions in the southeastern U.S. Light treatment had no significant (P > 0.10) effect on the incidence of leg abnormalities in either experiment. However, in Experiment 1, there was a light treatment by sex interaction; leg abnormalities were greater for males on Treatment R than Treatment S. In Experiment 2, females had a higher incidence of leg abnormalities than males (8.29 vs 4.73%). There was a diet by sex interaction for the incidence of leg abnormalities in Experiment 2; females had a greater incidence of leg abnormalities than males on Treatment A. In both experiments, the incidence was greater with dietary treatments containing roxarsone (P < 0.10). The percentage of leg abnormalities was greater in Experiment 2 than Experiment 1. Leg abnormalities were primarily due to fibrosis of the gastrocnemius tendons and tendon sheaths.

Color of broiler skin was evaluated after exposure to organic acids under various concentrations and simulated potential plant application conditions. Breast skin from chilled broiler carcasses was treated with acetic (AA), citric (CA), lactic (LA), malic (ML), mandelic (MN), propionic (PA), or tartaric (TA) acids at 0.5, 1, 2, 4, and 6% concentrations. Each acid and concentration was applied in simulated dip (23 C for 15 s), scalder (50 C for 2 min), and immersion chiller (1 C for 60 min) conditions. A tap water control was included with each application method. Objective color values of L* (lightness), a* (redness), and b* (yellowness) were measured before and after the treatments to calculate color differentials under a factorial arrangement of organic acids and concentrations. Skin lightness increased (P < 0.01) in simulated chiller as compared to dip and scalder applications. Skin redness was reduced significantly in scalder, and yellowness in dip and scalder applications, respectively. In simulated dip application, with the exception of PA, all acids decreased lightness and increased redness and yellowness values. Propionic acid had little affect on lightness and redness values, but decreased yellowness values. In simulated scalder application, with the exception of PA, all acids decreased lightness with increasing concentration. The redness values changed little in scalder application. However, yellowness values were increased with all acids, except for PA, which decreased yellowness values. In simulated chiller conditions, all acids, except for PA, decreased lightness and redness and increased yellowness values. Propionic acid increased lightness and decreased yellowness values significantly in chiller conditions. Alterations in skin color should be taken into account in the selection and application of organic acids as carcass disinfectants.

1Department of Animal Sciences, Purdue University, West Lafayette, Indiana 47907; 2Department of Animal and Food Sciences, Texas Tech University, Lubbock, Texas 79409; 3Department of Poultry Science, Auburn University, Auburn, Alabama 36849; 4Department of Poultry Science, University of Arkansas, Fayetteville, Arkansas 72701; 5Poultry Production and Product Safety Research Unit, USDA, Agricultural Research Service, Poultry Science Center, University of Arkansas, Fayetteville, Arkansas 72701; 6Novus International, Inc., St. Louis, Missouri 63141; 7Poultry Science Association, Savoy, Illinois 61874; 8Department of Animal and Food Sciences, University of Delaware, Georgetown, Delaware 19947; 9Institute for Conservation Leadership, Bozeman, Montana 59715; 10Department of Animal Science, University of Minnesota, St. Paul, Minnesota 55108; 11Department of Animal Sciences, University of Kentucky, Lexington, Kentucky 40546; 12Embrex, Inc., Research Triangle Park, North Carolina 27709; 13Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada T6G 2P5; 14Department of Surgery, Section of Urology, Medical College of Georgia, Augusta, Georgia 30912; 15Animal Health/Nutrition, Archer-Daniels-Midland Co., Quincy, Illinois 62301; 16Department of Animal Science, University of Tennessee, Knoxville, Tennessee 37996; 17Akey, Inc., Marysville, Ohio 43040; 18Department of Poultry Science, University of Georgia, Athens, Georgia 30605; 19Department of Poultry Science, North Carolina State University, Raleigh , North Carolina 27695; 20Department of Animal Science, University of Nebraska, Lincoln, Nebraska 68583; and 21Department of Animal and Food Sciences, University of Delaware, Newark, Delaware 19716

The purpose of this study was to measure plasma corticosterone and thyroid hormone concentrations in broilers exposed to various photoschedules. Day-old male broilers were placed on litter floors in light-controlled chambers. Four chambers were randomly assigned to each of four light treatments: 1) 23 h light (L):1 h dark (D) from 1 to 56 d of age (designated extended, E); 2) 1L:3D from 1 to 56 d (intermittent, I); 3) 6L:18D from 1 to 14 d and 1L:3D from 15 to 56 d (brief-I, BI); and 4) 6L:18D from 1 to 14 d and 23L:1D from 15 to 56 d (brief-E, BE). Blood samples were collected 0, 4, and 20 h after lights-on (1200 h) at 13, 41, and 55 d of age. Corticosterone concentration did not differ among light treatments or collection times and was decreased at 41 d compared with 13 d (.65 vs 2.11 ng/mL). Triiodothyronine (T3) increased and thyroxine (T4) decreased with age. At 13 d, there were light treatment by sampling time interactions for T3 and T4. Plasma T3 was elevated in Treatments BI (3.11 ng/mL) and BE (3.40 ng/mL) compared with Treatments E (2.39 ng/mL) and I (2.30 ng/mL) at 0 h; the former two treatments showed decreased T3 concentrations at 4 and 20 h compared with 0 h. Plasma T4 showed reciprocal changes to T3. There were no differences in T3 or T4 for light treatments or sampling times at 41 and 55 d. The light treatments did not cause severe stress, and elevated T3 concentrations in Treatments BI and BE at 13 d were most likely associated with feeding during the dark period.

A total of 2,560 male broilers from eight commercial strain-crosses were growth to 42 days of age on common starter (1 to 21 days; 23.06% CP, 3,217 kcal ME/kg) and grower (21 to 42 days; 20.14% CP, 3,224 kcal ME/kg) rations. All strain-crossed subsequently received finisher diets (17.95% CP; 3,186 kcal ME/kg) containing either .85 or .95% lysine from 42 to 53 days of age. Further-processing yields were determined on 12 birds per pen, selected within +/- 10% of the replicated pen (8 pens per strain-cross, 40 birds per pen) average weight. The strain-crosses differed significantly (P less than .05) in BW (1, 21, 42, and 53 days), weight gain (WG), feed:gain ratio (1 to 21 and 21 to 42 days), and mortality rate (1 to 21 days). The lysine effect during the finisher period was significant for 53-day BW and WG from 1 to 53 days. Chilled carcass (CC) and abdominal fat (AF) weights, CC yield (percentage, excluding AF), AF yield (percentage of CC weight), Pectoralis major, Pectoralis minor, total deboned breast (TDB), drumstick, thigh, wing, and residual "cage" and skin yields varied among the strain-crosses. A significant weight and yield response to lysine was observed for TDB. Variation observed among strain-cross in live performance, further-processing yields, and response to additional lysine is attributed to differences in rate of growth and degree of maturity at market age. Furthermore, the lysine requirement during the finisher period for optimum breast meat yield may be higher than that recommended by the National Research Council in 1984.