Estimates of genetic parameters, and cluster and principal components analyses of breeding values related to egg production traits in a White Leghorn population

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of broiler breeder genetic, diet type, and feeding program on maternal antibody transfer and development of lymphoid tissues in chicken progeny

Maternal antibody (MatAb) transfer is important for early chicken survivability. Diet composition and the amount of feed given to breeder pullets during rearing may affect the development of immunity and the transfer of MatAb to progeny, and could affect progeny performance and resistance to disease. The effects of broiler breeder nutrition and feeding management practices were evaluated for the transfer of MatAb to progeny and for spleen and bursa development at hatching in 2 genetic strains (A and B). In this experiment, the levels of MatAb against Newcastle disease virus were assessed by enzyme-linked immunosorbent assays in serum samples taken of pedigreed chicken progeny from hatching to 13 d of age. Chickens were fed corn-and wheat-based diets, as were their parents. The breeder feeding program and diet type altered the Newcastle disease virus MatAb found in progeny at hatching and affected how long these antibodies were maintained in circulation. Bursal follicle size at hatching was influenced by an interaction among all factors evaluated. Percentage of white pulp in the spleen was affected mainly by genetic strain and diet type, but responses varied according to the breeder feeding program. It was concluded that breeder feeding programs influence MatAb transfer and half-life, and may also affect the early development of lymphoid tissues.

Detection of T lymphocytes in intestine of broiler chicks treated with Lactobacillus spp. and challenged with Salmonella enterica serovar enteritidis

The expression of immune response in the form of leukocytic infiltrate by CD3+, CD4+, and CD8+ cells in the epithelium and in the intestinal lamina propria of chicks was studied in the present work by means of immunohistochemical reaction. The chicks were treated with Lactobacillus spp. or cecal microflora (CM) and experimentally challenged or not with Salmonella enterica serovar Enteritidis. The 320 birds utilized were divided into 4 groups containing 80 chicks each and submitted to treatments with Lactobacillus reuteri, Lactobacillus salivarius, Lactobacillus acidophilus, and CM. Each group was subdivided into 4 subgroups of 20 birds each and classified into a subgroup that did not receive treatment (negative control), subgroup treated, subgroup treated and challenged with Salmonella Enteritidis, and subgroup only challenged with Salmonella Enteritidis (positive control). The results obtained show that the treatment with L. reuteri, L. salivarius, L. acidophilus, or CM and challenged or not with Salmonella Enteritidis determine immune response in the form of leukocytic infiltrate by CD3+ and CD8+ lymphocytes followed by CD4+ in the epithelium and in the lamina propria of the duodenum, jejunum, and cecum of chicks up to 12 d of age. The quantity of CD3+ lymphocytes was significantly higher (P < 0.05) in the intestine of chicks treated with L. acidophilus or CM and challenged or not with Salmonella Enteritidis; however, the higher quantity of CD8+ lymphocytes was in the intestine of chicks treated with CM and challenged with Salmonella Enteritidis. The duodenum was the segment in which the immune response by T cells (CD3+, CD4+, and CD8+) was stimulated with the greatest intensity, followed by, respectively, the jejunum and cecum. The quantity of CD3+ lymphocytes present in the duodenum, jejunum, and cecum increases with the age of chicks, independent of the stimulus determined by treatments or challenge.

Effect of Phytase Supplementation in Diets on Nutrient Digestibility and Performance in Broiler Chicks

A performance trial was conducted with broiler chicks to Study the effect of phytase (PHY) supplementation in diets formulated With reduced AME, Ca, and P. The nutrient digestibility was determined during the 14- to 21-d and 28- to 35-d periods. The treatments consisted of 3 diets (NC1, NC2. NC3) differing ill nutrient content and each diet with Or without supplemental PHY (NC1, 0 oi 500; NC2, 0 or 750; NC3, 0 or 1,000 U of PHY/kg feed) and I positive control diet (PC). Compared with the PC diet. negative control diets (NC) resulted in lower AME and apparent ileal amino acid digestibility for some amino acids. Phytase Supplementation of the NC diets increased AME. apparent ileal amino acid digestibility, and apparent ileal crude protein digestibility. Phytase addition also increased mineral absorption in 2 1 - and 35-d-old broilers fed NC diets. Reduced nutrient digestibility appears to be I factor in the weight gain and feed intake results. Reducing Ca and P content reduced feed intake in a stepwise fashion in the NC diets. Phytase increased feed intake and generally improved nutrient digestibility, which resulted in an increase in digestible nutrient intake. Averaged across NC diets. PHY improved body weight. Bone-breaking strength was the most consistent predictor of Ca and P reduction. All NC diets had significantly lower bone-breaking strength than the PC. Phytase supplementation of the NC diets gave bone-breaking strengths that were comparable to the PC. Diets with PHY had the highest bioeconomic index.

Performance and physiological parameters of broiler chickens subjected to fasting on the neonatal period

Broiler chicks aged 12 h after hatching were allotted according to a block design in a 7 x 2 factorial schedule of 14 treatments and four replications of 50 chicks each one. The main experimental factors were fasting for 0, 6, 12, 18, 24, 30, and 36 h after chick placement and sex. Independent of sex, fasting had a negative linear effect on weight and productivity of broilers at market age (42 d) without affecting feed conversion or mortality index. Groups subjected to 18 and 36 h of fasting after placement, corresponding to 30 and 48 h posthatching fasting, had lower biometrical values for small intestine (length, weight, and size; villus height; and crypt depth) than chicks fed immediately after placement. According to the Pearson test, BW of birds at 21 and 42 d were significantly correlated to BW at 7 d (r = 0.77) and 21 d (r = 0.45), respectively. Males performed better than females but had higher mortality rates. Fasting did not influence serum concentrations of corticosterone or sexual steroid hormones. Nevertheless, early signs of sexual dimorphism arose from the high estradiol (E2) concentration on female serum. Heterophil:lymphocyte ratio was not different among treatments, indicating that early fasting did not seem to be a stress factor 21 or 42 d after fasting. The results suggested a maximum fasting of 24 h after hatching in order to preserve broiler productivity at market age.

Combination of CDF and D0 measurements of the W boson helicity in top quark decays

We report the combination of recent measurements of the helicity of the W boson from top quark decay by the CDF and D0 collaborations, based on data samples corresponding to integrated luminosities of 2.7-5.4fb -1 of pp̄ collisions collected during Run II of the Fermilab Tevatron collider. Combining measurements that simultaneously determine the fractions of W bosons with longitudinal (f 0) and right-handed (f +) helicities, we find f 0=0.722±0.081[±0.062(stat)±0.052(syst)] and f +=-0.033±0.046[±0.034(stat)±0.031(syst)]. Combining measurements where one of the helicity fractions is fixed to the value expected in the standard model, we find f 0=0.682±0. 057[±0.035(stat)±0.046(syst)] for fixed f + and f +=-0.015±0.035[±0.018(stat)±0.030(syst)] for fixed f 0. The results are consistent with standard model expectations. © 2012 American Physical Society.

Combination of the top-quark mass measurements from the Tevatron collider

The top quark is the heaviest known elementary particle, with a mass about 40 times larger than the mass of its isospin partner, the bottom quark. It decays almost 100% of the time to a W boson and a bottom quark. Using top-antitop pairs at the Tevatron proton-antiproton collider, the CDF and D0 Collaborations have measured the top quark's mass in different final states for integrated luminosities of up to 5.8fb -1. This paper reports on a combination of these measurements that results in a more precise value of the mass than any individual decay channel can provide. It describes the treatment of the systematic uncertainties and their correlations. The mass value determined is 173.18±0.56(stat)±0.75(syst)GeV or 173.18±0.94GeV, which has a precision of ±0.54%, making this the most precise determination of the top-quark mass. © 2012 American Physical Society.

Informe del Octavo Período de Sesiones del Comité de Desarrollo y Cooperación del Caribe, Puerto Príncipe, Haití, 6 al 12 de junio de 1984 = Report of the Eighth Session of the Caribbean Development and Co-operation Committee, Port-au-Prince, Haiti, 6-12 June 1984

Presenta la organizacion de la reunion, el resumen de los debates, conclusiones y recomendaciones sobre los temas: ejecucion del programa de trabajo del CDCC desde el 7o periodo de sesiones; proyecto de programa de trabajo para el bienio 1986-1987; accion sobre resoluciones aprobadas en el 6o y 7o periodo de sesiones del CDCC; resoluciones de CEPAL que tienen consecuencias para el CDCC; y admision de las Islas Virgenes Britanicas y las Islas Virgenes de Estados Unidos como miembros asociados del CDCC.

Multiplicity and transverse momentum dependence of two- and four-particle correlations in pPb and PbPb collisions

Measurements of two- and four-particle angular correlations for charged particles emitted in pPb collisions are presented over a wide range in pseudorapidity and full azimuth. The data, corresponding to an integrated luminosity of approximately 31nb-1, were collected during the 2013 LHC pPb run at a nucleon-nucleon center-of-mass energy of 5.02 TeV by the CMS experiment. The results are compared to 2.76 TeV semi-peripheral PbPb collision data, collected during the 2011 PbPb run, covering a similar range of particle multiplicities. The observed correlations are characterized by the near-side (|δφ|≈0) associated pair yields and the azimuthal anisotropy Fourier harmonics (vn). The second-order (v2) and third-order (v3) anisotropy harmonics are extracted using the two-particle azimuthal correlation technique. A four-particle correlation method is also applied to obtain the value of v2 and further explore the multi-particle nature of the correlations. Both associated pair yields and anisotropy harmonics are studied as a function of particle multiplicity and transverse momentum. The associated pair yields, the four-particle v2, and the v3 become apparent at about the same multiplicity. A remarkable similarity in the v3 signal as a function of multiplicity is observed between the pPb and PbPb systems. Predictions based on the color glass condensate and hydrodynamic models are compared to the experimental results. © 2013 CERN.

Measurement of the Bs0→μ+μ- branching fraction and search for B0→μ+μ- with the CMS experiment

Results are presented from a search for the rare decays Bs0→μ+μ- and B0→μ+μ - in pp collisions at √s=7 and 8 TeV, with data samples corresponding to integrated luminosities of 5 and 20 fb-1, respectively, collected by the CMS experiment at the LHC. An unbinned maximum-likelihood fit to the dimuon invariant mass distribution gives a branching fraction B(Bs0→μ+μ-)=(3.0-0.9+1.0) ×10-9, where the uncertainty includes both statistical and systematic contributions. An excess of Bs0→μ+μ- events with respect to background is observed with a significance of 4.3 standard deviations. For the decay B0→μ+μ- an upper limit of B(B0→μ+μ-)<1.1×10 -9 at the 95% confidence level is determined. Both results are in agreement with the expectations from the standard model. © 2013 CERN. Published by the American Physical Society under the terms of the.

Measurement of the W-boson helicity in top-quark decays from t(t)over-bar production in lepton plus jets events in pp collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Jet and underlying event properties as a function of charged-particle multiplicity in proton-proton collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)