74 Ge( n , γ ) cross section below 70 keV measured at n_TOF CERN.

Neutron capture reaction cross sections on 74 Ge are of importance to determine 74 Ge production during the astrophysical slow neutron capture process. We present new resonance data on 74 Ge( n , γ ) reactions below 70 keV neutron energy. We calculate Maxwellian averaged cross sections, combining our data below 70 keV with evaluated cross sections at higher neutron energies. Our stellar cross sections are in agreement with a previous activation measurement performed at Forschungszentrum Karlsruhe by Marganiec et al., once their data has been re-normalised to account for an update in the reference cross section used in that experiment.

Testicular thermoregulation, scrotal surface temperature patterns and semen quality of water buffalo bulls reared in a tropical climate.

This study evaluated the capacity of thermoregulation and its consequences on the scrotal surface temperature patterns and semen quality of buffalo bulls raised in a wet tropical climate. Eleven water buffaloes were evaluated in the rainiest, in the transitional and in the less rainy season. Air temperature and humidity were consistently high, but the animals did not show thermal stress in any season. The scrotal temperature gradient of buffalo bulls using infrared thermography was described, and three parallel and decreasing thermal bands were characterised. Sperm quality (n = 176 ejaculates) was maintained in normal parameters over the periods. Pearson's coefficients showed that sperm volume and progressive motility were negatively correlated with ocular globe, epididymal tail and minimum scrotal temperatures (p < .01). Sperm membrane integrity was negatively influenced by increases in epididymal tail and minimum scrotal temperatures (p < .01). Ocular globe temperature also showed positive correlation with rectal, spermatic cord, and epididymal tail temperatures (p < .01). Therefore, even under high temperature and humidity, the thermoregulatory system was effective in preventing heat stress and the normality of scrotal surface temperatures, spermatogenesis and sperm maturation were maintained.

First Measurement of Several ß-Delayed Neutron Emitting Isotopes Beyond N=126.

The ß-delayed neutron emission probabilities of neutron rich Hg and Tl nuclei have been measured together with ß-decay half-lives for 20 isotopes of Au, Hg, Tl, Pb, and Bi in the mass region N≳126. These are the heaviest species where neutron emission has been observed so far. These measurements provide key information to evaluate the performance of nuclear microscopic and phenomenological models in reproducing the high-energy part of the ß-decay strength distribution. This provides important constraints on global theoretical models currently used in r-process nucleosynthesis.

Assessment of surface temperatures of buffalo bulls (Bubalus bubalis) raised under tropical conditions using infrared thermography / Avaliação de temperaturas superficiais de touros bubalinos (Bubalus bubalis) criados em ambiente tropical com uso da termografia infravermelha

This paper aimed to evaluate the surface temperatures of buffalo bulls using infrared thermography, considering four distinct anatomical parts over time, and to correlate surface temperatures and thermal comfort indexes. The humid tropical climate (Kõppen's Afi) was predominant in the research station where the experiment was performed and the trial lasted from April to August. Ten bulls (n=10) were evaluated every 25 days (morning: 6:00-9:00; afternoon: 12:00-15:00) and the parameters assessed were respiratory rate (RR), rectal temperature (RT), and the thermograms of surface temperature for orbital area (ORB), right flank (RF), left flank (LF) and scrotum (SCR). Climatological data was continuously monitored and the Temperature and Humidity Index (THI) and the Index of Comfort of Benezra (ICB) were calculated. The average values of THI were ≥78, and significant differences between shifts were observed (P<0.05). The ICB ranged from 1.96 to 2.25 and significant differences were observed for shifts and throughout the months (P<0.05). The averages of surface temperatures were RT=38.2±0.5°C, ORB=36.1±0.8°C, LF=33.5±2.5°C, RF=35.4±1.7ºC and SCR=33.3±1.1°C, which exhibited significant differences for shifts and throughout the months (P<0.05). Positive correlations were obtained between THI and ORB (0.72), RF (0.77), LF (0.75) and SCR (0.41) (P<0.0001). The maximum temperature of ORB showed the highest correlation with RT (0.58, P<0.0001). Therefore, the surface temperatures are subject to climatic variations and increase throughout the day, due to the variation in thermal comfort indexes, and the maximum ORB temperature was the parameter most related to rectal temperature. Lastly, the results indicate that IRT may be a useful non-invasive and accurate tool to detect the variations in ORB, LF, RF and SCR temperature in buffalo bulls.

O presente trabalho visou avaliar as temperaturas superficiais de diferentes regiões anatômicas de búfalos ao longo do tempo, por meio da termografia infravermelha, e correlacioná-las a índices bioclimatológicos de conforto térmico. O ensaio foi realizado em região de clima tropical úmido (Afi de Kõppen), de abril a agosto. Dez touros (n=10) foram avaliados a cada 25 dias (manhã: seis-nove horas; tarde: 12-15h), quanto à frequência respiratória (FR), temperatura retal (TR) e imagens termográficas da órbita ocular (ORB), flanco direito (FLd), flanco esquerdo (FLe) e escroto (ESC). Os dados climatológicos foram ininterruptamente monitorados, e calculados o índice de temperatura e umidade (ITU) e o índice de conforto de Benezra (ICB). O ITU foi ≥78, com diferença entre turnos (P<0,05). Já o ICB variou de 1,96 a 2,25 e apresentou diferenças ao longo dos meses e entre turnos (P<0,05). As temperaturas observadas foram de TR=38,2±0,5ºC, ORB=36,1±0,8ºC, FLd=33,5±2,5ºC, FLe=35,4±1,7ºC e ESC=33,3±1,1ºC, as quais variaram significativamente ao longo dos meses e entre turnos (P<0,05). O ITU apresentou correlações positivas com ORB (0,72), FLd (0,77), FLe (0,75) e ESC (0,41) (P<0,0001). A temperatura máxima de ORB apresentou a maior correlação com a TR (0,58; P<0,0001). Portanto, as temperaturas superficiais dos animais sofrem interferências das variações climáticas e se elevam ao longo do dia, devido à variação nos índices de conforto térmico; a temperatura máxima de ORB foi o parâmetro mais condicionado à temperatura retal. Também, as oscilações de temperatura de superfície de ORB, FLd, FLe e ESC podem ser aferidas em bubalinos com o uso da termografia infravermelha, de modo preciso e não invasivo.

Total Absorption Spectroscopy Study of (92)Rb Decay: A Major Contributor to Reactor Antineutrino Spectrum Shape.

The antineutrino spectra measured in recent experiments at reactors are inconsistent with calculations based on the conversion of integral beta spectra recorded at the ILL reactor. (92)Rb makes the dominant contribution to the reactor antineutrino spectrum in the 5-8 MeV range but its decay properties are in question. We have studied (92)Rb decay with total absorption spectroscopy. Previously unobserved beta feeding was seen in the 4.5-5.5 region and the GS to GS feeding was found to be 87.5(25)%. The impact on the reactor antineutrino spectra calculated with the summation method is shown and discussed.

Enhanced γ-Ray Emission from Neutron Unbound States Populated in ß Decay.

Total absorption spectroscopy is used to investigate the ß-decay intensity to states above the neutron separation energy followed by γ-ray emission in (87,88)Br and (94)Rb. Accurate results are obtained thanks to a careful control of systematic errors. An unexpectedly large γ intensity is observed in all three cases extending well beyond the excitation energy region where neutron penetration is hindered by low neutron energy. The γ branching as a function of excitation energy is compared to Hauser-Feshbach model calculations. For (87)Br and (88)Br the γ branching reaches 57% and 20%, respectively, and could be explained as a nuclear structure effect. Some of the states populated in the daughter can only decay through the emission of a large orbital angular momentum neutron with a strongly reduced barrier penetrability. In the case of neutron-rich (94)Rb the observed 4.5% branching is much larger than the calculations performed with standard nuclear statistical model parameters, even after proper correction for fluctuation effects on individual transition widths. The difference can be reconciled by introducing an enhancement of 1 order of magnitude in the photon strength to neutron strength ratio. An increase in the photon strength function of such magnitude for very neutron-rich nuclei, if it proves to be correct, leads to a similar increase in the (n,γ) cross section that would have an impact on r process abundance calculations.

Adição de óleo de palma na dieta sobre a lipidemia e a qualidade do sêmen de bubalinos (Bubalus bubalis) / Addition of palm oil to diet on serum lipid profile and seminal quality of buffaloes (Bubalus bubalis)

O estudo visou investigar o efeito da suplementação dietética com óleo de palma sobre o perfil sérico lipídico e as características seminais de touros bubalinos (Bubalus bubalis), bem como suas correlações. Doze touros foram alocados no Grupo CONT (n=5) ou Grupo ÓLEO (n=7) e receberam alimentação isoproteica composta por silagem de milho e concentrado (milho triturado, farelo de trigo e ureia), com proporção volumoso/concentrado de 50%, durante 130 dias (Períodos 1 e 2). Diferencialmente, óleo de palma foi adicionado ao concentrado (2% MS) do Grupo ÓLEO. Sêmen e sangue foram colhidos quinzenalmente. Houve aumento nas concentrações séricas de colesterol, HDL e lipídios totais nos animais do Grupo ÓLEO, enquanto o período influenciou nas taxas de colesterol, LDL, lipídios totais e VLDL (P<0,05). Houve decréscimo no turbilhonamento e discreta redução na integridade de membranas nos animais do Grupo ÓLEO (P<0,05). Correlações significativas foram encontradas entre triglicerídeos e defeitos menores (r=-0,412; P=0,006), LDL e defeitos totais (r=-0,333; P=0,030), lipídios totais e defeitos menores (r=-0.366; P= 0,017), lipídios totais e defeitos totais (r=-0.309; P= 0,046), e VLDL e viabilidade espermática (r=0,381; P=0,012), apontando efeitos positivos da maior lipidemia na morfologia e na viabilidade espermática. O uso de óleo de palma alterou o perfil lipídico sérico, mas não favoreceu per se os parâmetros seminais relacionados com o potencial de fertilidade dos touros.

The study aimed to investigate the effect of dietary supplementation with palm oil on serum lipid profile, the seminal characteristics of buffaloes (Bubalus bubalis) and the correlations between them. Twelve bulls were divided into Group CONT (n = 5) or Group OIL (n = 7). Animals in both groups were fed with isoproteic diets composed of corn silage and concentrated (ground corn, wheat bran and urea), with 50% forage/concentrate ratio, during 130 days (Periods 1 and 2). Palm oil (2%DM) was added to diet offered to Group OIL. Semen and blood samples were collected every two weeks. Increased serum levels of cholesterol, HDL and total lipids were observed for Group OIL, while the period influenced on cholesterol, LDL, total lipids and VLDL (P<0,05). Treatment decreased gross motility (P<0.05) and slightly reduced sperm membrane integrity (P<0.05) in animals of Group OIL. There were significant correlations between triglycerides and minor defects (r=-0.412, P=0.006), LDL and total defects (r=-0.333, P=0.030), total lipids and minor defects (r=-0.366, P=0.017), VLDL and spermatic viability (r=0.381, P=0.012), and total lipids and totals defects (r=-0.309, P=0.046), highlighting positive effects of higher lipid serum levels on sperm morphology and viability. The incorporation of palm oil in the diet altered the serum lipid profile, but it showed no positive effect on seminal parameters related to the potential of bull fertility.

Neutron capture cross section of unstable 63Ni: implications for stellar nucleosynthesis.

The 63Ni(n,γ) cross section has been measured for the first time at the neutron time-of-flight facility n_TOF at CERN from thermal neutron energies up to 200 keV. In total, capture kernels of 12 (new) resonances were determined. Maxwellian averaged cross sections were calculated for thermal energies from kT=5-100 keV with uncertainties around 20%. Stellar model calculations for a 25M⊙ star show that the new data have a significant effect on the s-process production of 63Cu, 64Ni, and 64Zn in massive stars, allowing stronger constraints on the Cu yields from explosive nucleosynthesis in the subsequent supernova.

Carcass quality of buffalo (Bubalus bubalis) finished in silvopastoral system in the Eastern Amazon, Brazil / Qualidade da carcaça de búfalos (Bubalus bubalis) terminados em sistema silvipastoril na Amazônia Oriental, Brasil

The influence of the diet on the quality of buffalo (Bubalus bubalis) carcasses of crossbred Murrah and Mediterranean, concentrate fed on traditional (corn/soybean) or on agro-industrial residues (palm oil and coconut cakes) was studied. The animals were sacrificed in a slaughterhouse, and physical and physical-chemical analyses in the carcasses were carried out after 24 hours, and instrumental color and texture analyses of the Longissimus dorsi were carried out 48 hours after cooling. The animals supplemented with palm oil cake had better carcass conformation and fat trim, and differences (P<0.05) in the percentage of fat in the carcass fat thickness and coverage were observed.

Avaliou-se a influência da dieta sobre a qualidade de carcaça de búfalos mestiços das raças Murrah e Mediterrâneo, alimentados com concentrado tradicional - milho/soja - ou resíduos agroindustriais - tortas de coco e dendê. Os animais foram sacrificados em abatedouro comercial, e realizadas análises físicas e físico-químicas na carcaça, após 24 horas, e de cor e textura instrumentais no músculo Longissimus dorsi, após 48 horas de resfriamento. Os animais suplementados com a torta de dendê adquiriram melhor conformação de carcaça e acabamento de gordura, e observaram-se diferenças (P<0,05) no percentual de gordura na carcaça e na espessura de gordura de cobertura.

Antibacterial effectiveness of several irrigating solutions and the Endox Plus system - an ex vivo study.

AIM: To compare the ex vivo antibacterial effectiveness of the Endox Plus system and sodium hypochlorite (NaOCl) in combination with BioPure MTAD (Tulsa Dental, Tulsa, OK, USA) or with EDTA in Enterococcus faecalis-contaminated root canals. METHODOLOGY: After initial preparation, the root canals of 70 single-rooted human teeth were inoculated with E. faecalis (ATCC 29212) and incubated for 21 days. Specimens were divided into five groups: Endox Plus/saline; 2.5% NaOCl/MTAD; 2.5% NaOCl/EDTA; saline (positive control); negative control (root canals not prepared, nor irrigated). Samples were collected using paper points. Microbiological analysis evaluated the number of CFUs. Data were analysed by anova and Tukey tests at 0.05 significance. RESULTS: All specimens had bacterial growth after the incubation period, with similar CFU per mL counts (P > 0.05). After chemo-mechanical preparation, the number of bacteria in all groups reduced, except for the negative control. No significant differences were observed between 2.5% NaOCl/MTAD and 2.5% NaOCl/EDTA, but these groups had lower CFU counts than the other groups (P < 0.05). In the final samples, an increase in the bacterial counts was observed for Endox Plus/saline, 2.5% NaOCl/MTAD, 2.5% NaOCl/EDTA and saline (P < 0.05) with no significant differences between these groups. CONCLUSIONS: This ex vivo study revealed that the Endox Plus system was associated with a reduced antibacterial effectiveness compared with conventional irrigation using 2.5% NaOCl/MTAD and 2.5% NaOCl/EDTA. All irrigation procedures allowed recovery of bacteria 7 days after treatment, demonstrating persistence of contamination within the root canal system.

Heterotopic neuroglial tissue as a congenital laterocervical mass: a case report.

Heterotopic neuroglial tissue in the head and neck area is a rare clinical entity which can cause airway obstruction and feeding problems during the neonatal period. The case is presented of heterotopic neuroglial tissue as a congenital laterocervical and intraoral mass in a neonate.

Effects of two new steroids and cyproterone on some biomarkers of oxidative stress and serotonergic system on rat prostate and brain.

The purpose of this study was to evaluate the effect of cyproterone acetate (CPA, A) compared with new synthetic steroids 3alpha-acetoxy-5,6-epoxy-16-pregnen-20-one (B) and 17alpha-hydroxy-16beta-methyl-1,4,6-pregnatriene-3,20-dione (C) in rat prostate and brain. Groups of animals were treated either with A, B or C (4 mg kg(-1) day(-1)) by the intraperitoneal route for 5 days. Levels of reduced glutathione (GSH), 5-hydroxy-indole acetic acid (5-HIAA), lipid peroxidation (as thiobarbituric acid reactive substances, TBARS) and the activities of Na(+), K(+)- and total ATPases were assayed in prostate and brain for each group of animals including a control group. No appreciable changes were shown in Na(+), K(+)-ATPase and total ATPases and TBARS on prostate and brain of rats that received A, B and C steroids. However, the levels of GSH and 5-HIAA decreased significantly (P < 0.05) in both tissues for the steroids assayed. It is concluded that CPA and the homologues B and C steroids induce changes in the levels of GSH and serotonin in rat prostate and brain.

High prevalence of antibodies against Chlamydiaceae and Chlamydophila abortus in wild ungulates using two "in house" blocking-ELISA tests.

Few data are available on the prevalence and relevance of chlamydiae in wild mammals, and even fewer studies have been conducted to determine the prevalence of Chlamydophila abortus in wildlife hosts, most probably due to the absence of suitable species-specific serological assays for testing sera from wild animals. In light of this, we have developed two in-house blocking-ELISA tests for detection of antibodies against Chlamydiaceae and C. abortus in wild ungulates, and analyzed the relationship between geographical and biological factors and the prevalence of antibodies against Chlamydiaceae and C. abortus in 434 wild ungulates from Spain, including sera from European wild boar, Red deer, Fallow deer, Roe deer, Mouflon, Barbary sheep, Southern chamois, and Iberian ibex. Serology revealed that 41.7+/-4% of the sera were positive for the b-ELISA-LPS (Chlamydiaceae-specific) and 18.9+/-3% for the b-ELISA-rPOMP (C. abortus-specific). Antibodies against Chlamydiaceae lipopolysaccharide (LPS) were detected in sera from all eight ungulate species, the prevalence ranging from 23 to 60%. Iberian ibex was the only wild ungulate not showing seropositivity to the C. abortus specific polymorphic outer membrane protein (POMP). The prevalence of anti-POMP antibodies in the other seven wild ungulate species ranged from 7 to 40%. While significant seroprevalence differences were detected among species and among sampling regions, no effect of age and sex was observed. The high prevalence levels found should be considered with regards to livestock and human health, and warrant further research.

The characterization of a murine model of mucopolysaccharidosis II (Hunter syndrome).

Mucopolysaccharidosis II (MPS II, Hunter syndrome in humans) is an X-linked inherited lysosomal storage disease caused by a deficiency in the lysosomal enzyme iduronate-2-sulfatase (I2S). I2S catalyses a step in the catabolism of glycosaminoglycans (GAGs) dermatan sulfate and heparan sulfate, and when it is deficient or absent GAGs accumulate in tissues and organs. Male knockout mice (IdS-KO), which lack the gene coding for I2S, exhibit many of the characteristics seen in the human disease. Compared to wild-type control mice, urine GAG excretion was elevated at 4 weeks of age and remained high throughout the lifespan, and tissue GAG levels were elevated as early as 7 weeks of age. Liver, spleen and other organs were significantly larger in the IdS-KO mice than in the wild-type. Radiographic examination revealed sclerosis and enlargement of the skull at 4 weeks of age and appendicular bone enlargement at 10-13 weeks of age. Micro CT scans showed severe periosteal bone formation at the lateral aspect of the distal tibia and calcification of the calcaneus tendon. This model was used in the development of idursulfase for treatment of MPS II and may continue to be useful in the evaluation of treatment strategies of this chronic and progressive disorder.

Los sucesos adversos en los hospitales españoles: Resultados del estudio eneas / No disponible

Declaración de intereses: Este trabajo es consecuencia del estudio ENEAS que fue realizado a través de un convenio de colaboración entre la Universidad Miguel Hernández y el Ministerio de Sanidad y Consumo, que lo financiación. Su realización fue aprobada por el Comité de Ética e Investigación Clínica de Aragón. Objetivo: Determinar la incidencia de pacientes con efectos adversos (EAs) en los hospitales españoles, establecer la proporción de EA que se producen en el periodo de prehospitalización, describir las causas inmediatas del EA, definir los EA evitables y conocer el impacto de los EA en términos de gravedad, exitus y/o prolongación de la estancia hospitalaria. Método: Estudio retrospectivo de cohortes. Muestra aleatoria estratificada de 24 hospitales, 6 de tamaño pequeño (de menos de 200 camas), 13 de tamaño mediano (de 200 a 499) y 5 de tamaño grande (mayor o igual 500 camas). Pacientes ingresados, cuya hospitalización fuera superior a 24 horas, que fueron dados de alta del 4 al 10 de junio de 2005. Se incluyeron los EA detectados durante la hospitalización y aquellos que fueron consecuencia de episodios de hospitalización previa en el mismo hospital. Resultados: La incidencia de pacientes con EA relacionados directamente con la asistencia hospitalaria fue de 8,4% (IC95%: 7,7% - 9,1%), que aumentá a 9,3% (IC95%: 8,6% - 10,1%) al incluir los EA del periodo de prehospitalización. La densidad de incidencia fue de 1,2 EA por cada 100 dí­as de estancia (IC95%: 1,1 - 1,3). La densidad de incidencia de EA moderados o graves fue de 5,6 EA por cada 1.000 días de estancia (IC95%: 4,9 - 6,3). El 42,8% de los EA se consideró evitable. Se observó un 13,2% de EA cuando el paciente presentaba factores de riesgo intrínsecos y un 5,2% cuando no los tení­a (p< 0,001) (AU)

Objective: To assess patients with AE incidence in Spanish hospitals, to estimate the proportion of AE occurring during the preadmission period, to describe the immediate causes of AE, to define the preventable AE and to identify the impact of AE in terms of severity, death or longer hospital stay. Method: Retrospective cohort study. Sample of 24 hospitals, 6 of them were small-sized hospitals (fewer than 200 beds), 13 medium-sized hospitals (between 200 and 499 beds) and 5 large-sized hospitals (500 or more beds). Patients who stayed more than 24 hours in the selected hospitals, who had a clinical record in these centres and who had been discharged between the 4th and the 10th of June 2005. AE detected during hospitalisation and those being consequence of previous admissions were included. Results: The incidence of patients with AE related directly to hospital care was 8.4% (95%CI: 7.7% - 9.1%) and rose 9.3% (95%CI: 8.6% - 10.1%) including those from the prehospitalisation period. The incidence density was 1.2 AE per 100 patient-days (95%CI: 1.1 - 1.3). The incidence of moderate and serious AE was 5.6 AE per 1000 patient-days (95%CI: 4.9% - 6.3%). In 66.3% of AE, additional procedures were required and in 69.9% additional reatments. Some 42.8% of AE were considered as avoidable. Some 13.2% of the subjects with some intrinsic risk factors developed AE compared to the 5.2% of the subjects who had no risk factors (p<0.001), and 9.5% of the subjects who had some extrinsic risk factors developed AE compared to 3.4% of the subjects who had not (p<0.001). The most frequent AE were those associated to medication (37.4%), hospital infections of any type (25.3%) and those related to technical problems during a procedure (25.0%) (AU)

A comparison of methods to determine amino acid digestibility of feed ingredients for chickens.

Two experiments were conducted to compare standardized ileal amino acid (AA) digestibility in 7- and 21-d-old chicks and true AA digestibility as determined by the precision-fed cecectomized rooster assay for several ingredients used in poultry feeds. Diets were formulated to contain soybean meal, cottonseed meal, poultry by-product meal, and fish meal in experiment 1 and corn, wheat, soybean meal, poultry by-product meal, feather meal, and fish meal in experiment 2 as the sole sources of protein. Celite, used as an indigestible marker, was added at 1.5% of the diet. The test diets were fed ad libitum to broiler chicks from 0 to 7 d of age in experiment 1 and from 4 to 7 and 17 to 21 d of age in experiment 2. Ileal digesta samples were collected after euthanizing the birds at 7 d of age in experiment 1 and at 7 and 21 d of age in experiment 2. Additionally, cecectomized, Single-Comb White Leghorn roosters were used for crop intubation of the test diets for determination of true AA digestibility. In experiment 1, AA digestibility of all ingredients tested was significantly lower at 7 d of age than when determined by the rooster assay. In experiment 2, no differences were detected between AA digestibility at 7 or 21 d of age in the chick assay for the majority of the indispensable AA. However, the AA digestibility coefficients obtained by the chick assay at 7 d and, in some cases, at 21 d of age, were significantly lower than those obtained by the rooster assay. In conclusion, there were differences in the AA digestibility coefficients obtained through the chick and the rooster assays. Such discrepancies could be associated with an age effect or the methodological differences between both methods.

Variations in the digestible lysine requirement of broiler chickens due to sex, performance parameters, rearing environment, and processing yield characteristics.

Four experiments were conducted to evaluate variations in the digestible lysine (DLYS) requirement estimates of broilers due to rearing environment, sex, or growth performance during the starter period (7 to 21 d) and due to sex, growth, and carcass yield characteristics during the grower period (21 to 38 d). In the first 3 experiments, chicks were allocated to either battery or floor pens. The fourth experiment was conducted during the grower period with birds reared in floor pens only. All the studies used a lysine-deficient corn-soybean meal-corn gluten meal basal diet formulated to be isonitrogenous and isocaloric. Treatments consisted of 5 graded levels of DLYS varying from 0.70 to 1.21% in the first 3 experiments and from 0.73 to 1.13% in the fourth experiment. The DLYS requirement was estimated by broken-line methodology based on body weight gain (BWG) and gain:feed ratio (G:F) for the starter period, and the same variables plus breast meat yield for the grower period. During the starter period, the average DLYS requirement of males based on BWG was slightly higher than that of females reared in battery (0.96 vs. 0.94%) or floor pens (0.98 vs. 0.93%). However, based on G:F, the average DLYS requirement of females was slightly higher than that of males reared in both battery (0.99 vs. 0.96%) and floor pens (1.01 vs. 0.99). The DLYS requirement based on G:F was higher than that based on BWG only for females in both rearing environments. Rearing environment did not affect the DLYS requirement of broilers during the starter period. In the grower period, the DLYS requirement of males was higher than that of females based on BWG (0.97 vs. 0.93%), but for G:F it was similar for both sexes (0.96%). The DLYS requirement for females based on G:F was higher than that based on BWG. The DLYS requirement for maximum breast meat yield of males (0.98%) or females (0.90%) was similar to the estimate for maximal growth performance.