Análisis multivariado de indicadores zoométricos de madurez sexual de gallinas reproductoras Campero INTA

The aim of the present study was to evaluate the behavior of the zoometric indicators involved in the biological process of sexual maturity through multivariate analysis to explain their joint behavior and characterize their development. We worked with 400 pullets belonging to 2 genotypes (synthetic E and the hybrid ES*A) that received two nutritional levels (control and treated) between weeks 5 and 22. Canonical analysis was performed to represent the linear association of the variables obtaining equations that allow explaining a portion of the total variance of the data independent of the remaining canonical components. Four canonical components were generated from week 22 and 24. The results of the week 22 showed that the first two components explain 94.87% of the observed variation. The first component (PCC) explains 81.86% of the variance and is positively and significantly correlated with comb index (ICr) (r=0.787; p<0.0001), hip width (ACa) (r=0.626; p<0.0001), abdominal length (LAb) (r=0.527; p=0.0001) and shows no significant association with cloacal width (ACl, r=-0.072; p=0.268), correlating mainly with comb index. The second component (SCC) explains 13.01% of the variance and is positively and significantly correlated with the four variables, but to a greater extent with ACl (r=0.921; p=0.0001) and to a lesser extent with ICr (r=0.233; p=0.0003), ACa (r=0.572; p<0.0001) and LAb (r=0.515; p<0.0001). The results for week 24 for the PCC explain 70.41% of the variance and correlate in a positive and significant way with the ICr (r=0.982; p<0.0001), the ACl (r=0.615; p<0.0001), ACa (r=0.423; p<0.0001) and LAb (r=0.459; p<0.0001, doing it mainly with the comb index. The SCC explains 26.98% of the variance and correlates , in a positive and significant way with the ACl (r=0.525; p<0.0001), ACa (r=0.887; p<0.0001) and LAb (r=0.671; p<0.0001), mainly correlating with hip width and does not show an association with the ICr (r=-0.017; p=0.799). This implies that, the higher the CCP value, the birds have essentially a higher comb index, cloacal width, hip width and abdominal length It is concluded that the increase in the allocation of nutrients produces a significant increase in the average value of the canonical component, which suggests an advance of sexual maturity in both E and ES*A of greater magnitude in hybrids.El objetivo del presente estudio fue evaluar el comportamiento de los indicadores zoométricos involucrados en el proceso biológico de la madurez sexual mediante análisis multivariado, para explicar su comportamiento conjunto y caracterizar su desarrollo. Se trabajó con 400 gallinas pertenecientes a 2 genotipos (sintética E y el híbrido ES*A) que recibieron dos planos nutricionales (control y tratado) entre las semanas 5 y 22. Se realizó análisis canónico para representar la asociación lineal de las variables, obteniendo ecuaciones que permiten explicar una porción de la variancia total de los datos independiente de las restantes componentes canónicas. Se generaron cuatro componentes canónicas de las semanas 22 y 24. Los resultados de la semana 22 arrojaron que las dos primeras componentes explican el 94,87% de la variación observada. La primera componente (PCC) explica el 81,86% de la variancia y se correlaciona en forma positiva y significativa con ICr (r=0,787; p<0,0001), ACa (r=0,626; p<0,0001), LAb (r=0,527; p=0,0001) y no muestra asociación significativa con ancho ACl (r=-0,072; p=0,268), correlacionando principalmente con el índice de cresta. La segunda componente (SCC) explica el 13,01% de la variancia y se correlaciona en forma positiva y significativa con las cuatro variables, pero en mayor medida con ACl (r=0,921; p=0,0001) y menor medida con ICr (r=0,233; p=0,0003), ACa (r=0,572; p<0,0001) y LAb (r=0,515; p<0,0001). Los resultados de la semana 24 para las PCC explica el 70,41% de la variancia y correlaciona en forma positiva y significativa con el ICr (r=0,982; p<0,0001), el ACl (r=0,615; p<0,0001), ACa (r=0,423; p<0,0001) y LAb (r=0,459; p<0,0001, haciéndolo principalmente con el índice de cresta. La SCC explica el 26,98% de la variancia y correlaciona, en forma positiva y significativa con el ACl (r=0,525; p<0,0001), ACa (r= 0,887; p<0,0001) y LAb (r=0,671; p<0,0001), correlacionando principalmente con el ancho de cadera y sin mostrar asociación con el ICr (r=-0,017; p=0,799). Esto implica que, a mayor valor de PCC las aves presentan esencialmente mayor índice de cresta, ancho de cloaca, ancho de cadera y longitud abdominal. Se concluye que el aumento en la asignación de nutrientes produce un aumento significativo en el valor promedio de la componente canónica, lo que sugiere un adelanto de la madurez sexual tanto en E como en ES*A de mayor magnitud en las híbridas

Efecto de la separación inicial por sexos sobre el porcentaje de uniformidad en gallos Campero INTA

En el presente trabajo se evalúa el efecto que produce la separación inicial de sexos sobre la uniformidad del plantel de reproductores machos Campero-INTA a lo largo del ciclo de cría y recría y a las 20 semanas de edad. Se utilizaron cuatro lotes de reproductores pesados provenientes del cruzamiento de las razas Cornish colorada, Plymouth Rock blanca, Rhode Island colorada y Anac. Cada lote, integrado por 300 hembras y 50 machos, fue dividido al azar a su llegada al establecimiento en unidades experimentales de 150 hembras y 25 machos. Durante las 5 primeras semanas de vida, en el grupo A (tratado) machos y hembras se alojaron en compartimientos separados, mientras que en el grupo B (control) ambos sexos se criaron en forma conjunta. En ambos grupos, los sexos se mantuvieron separados hasta el final de la recría (semana 20 de vida). La curva de uniformidad fue similar, en especial hasta las 15 semanas, con valores iniciales que oscilaron entre 77 y 70% (grupo A y B respectivamente), para luego descender marcadamente en los machos del grupo B, con valores algo inferiores al 40% al finalizar la etapa de cría. Al finalizar la fotosensibilización, los valores fueron de 86,7±9,4 y 63,32±8,7% para los grupos A y B respectivamente, diferencias que fueron estadísticamente significativas (p=0,01). A las 20 semanas la uniformidad correlacionó con fertilidad a las 48 semanas en el grupo A (r = 0,98 p<0,05), mientras que en los machos del Grupo B no correlacionó. Se considera esencial que machos y hembras se críen separados, en particular en las etapas iniciales del ciclo, para tener óptimos resultados en la fase de producción de huevos fértiles

Interacción genotipo-manejo de la alimentación en la producción de pollos camperos

Poultry meat production in semi-intensive management systems is an ecological modality that takes into account aspects related to animal welfare. Campero chicken is a bird with a slower growth rate than commercial broilers destined to the production of meat in this type of systems. The traditional feeding scheme includes the use of three types of food specially formulated for this purpose (starter, grower and finisher) which introduces management complications, particularly in relation to the availability of grower food for small producers. An alternative that would facilitate feeding management is a scheme based on only two types of food: starter and finisher. The aim of this work was to evaluate the effect of changing the traditional feeding scheme by an alternative one, replacing grower food with a mix of starter and finisher, in two genotypes of chicken with a different growth rate: the experimental three-way cross Campero Casilda and the two-way cross Campero INTA. The evidence indicates that the proposed change in the traditional feeding management does not affect body growth, feed conversion ratio and productive traits at slaughter, and that both genetic groups behave similarly, when grower diet is replaced by a mix of starter and finisher.La producción de carne aviar en sistemas de manejo semi-intensivo es una modalidad ecológica que contempla aspectos vinculados con el bienestar animal. El pollo Campero es un ave con menor velocidad de crecimiento que los parrilleros comerciales, destinado a la producción de carne. El esquema tradicional de alimentación incluye la utilización de tres tipos de alimentos especialmente formulados a tal fin (iniciador, crecimiento y terminador), lo cual introduce complicaciones en el manejo, particularmente en lo referido a la disponibilidad del alimento “crecimiento” para los pequeños productores. Una alternativa que facilitaría el manejo de estas aves es un esquema basado en sólo dos tipos de alimentos: iniciador y terminador. El objetivo de este trabajo fue evaluar el efecto del cambio del manejo tradicional de la alimentación por uno alternativo reemplazando el alimento “crecimiento” por una mezcla de iniciador y terminador, en dos genotipos de pollo Campero con diferente velocidad de crecimiento: el híbrido experimental de tres vías Campero Casilda y el híbrido simple Campero INTA. La evidencia indicó que el cambio en el manejo de la alimentación no afectó el crecimiento, la relación de conversión ni los caracteres a la faena. Ambos grupos genéticos se comportaron de manera equivalente, pudiendo obviarse la inclusión de la categoría “crecimiento” si se la reemplaza por una mezcla de iniciador y terminador

Ornamentos sexuales y caracteres productivos en gallinas Campero Casilda

In order to associate the size of sexual ornaments with reproductive and productive characters in hens from the three-way cross Campero Casilda, the comb [CI: length x height] and wattle indices [BI: length x width] were calculated. Individual data were graphed in a Cartesian system (X: IC; Y: IB) which was divided into four quadrants by two lines that intersect each axis at the level of their mean values. Birds with extreme values of both indices [Quadrant I (CI):> CI> IB and Quadrant III (CIII): <CI <IB] were identified and, for each of them, the productive characters at sexual maturity, four indicators of bone development at 30 and 71 weeks, the dynamic patterns of body weight and egg weight and the ratio of feed conversion to eggs in the first part of the laying cycle, were recorded. Birds with greater development of sexual ornaments (a) were precocious and began laying with eggs of lower weight, but with similar regularity and uniformity and presented (b) greater length of the tarsus and femur in both ages, greater diameter of the tarsus at 30 weeks and greater length of the tibia at 71 weeks of age, (c) higher exponential growth rate between the sixth and twentieth week but similar global growth pattern, (d) lower asymptotic egg weight, lower maturation rate for the character and lower theoretical weight of the first egg and (e) higher number of eggs of lower weight and similar feed conversion ratio between 26 and 35 weeks. Size combination of sexual ornaments is presented as an alternative for the early selection of the breeders.Con el objetivo de asociar el tamaño de los ornamentos sexuales con caracteres reproductivos y productivos en gallinas del cruzamiento de tres vías Campero Casilda se calcularon, en 97 aves de 30 semanas, los índices de cresta [IC: longitud x alto] y barbilla [IB: longitud x ancho]. Los datos individuales se graficaron en un sistema de ejes cartesianos (X: IC; Y: IB) el que se dividió en cuatro cuadrantes mediante dos rectas que intersectan a cada eje a nivel de los valores medios. Se identificaron las aves con valores extremos de ambos índices [Cuadrante I (CI): > IC > IB y Cuadrante III (CIII): < IC < IB] y, para cada una de ellas, se registraron los caracteres productivos a la madurez sexual, cuatro indicadores de desarrollo óseo a las 30 y 71 semanas, los patrones dinámicos del peso corporal y el peso del huevo y la relación de conversión en huevos en la primera parte del ciclo de postura. Las aves con mayor desarrollo de los ornamentos sexuales (a) fueron más precoces y comenzaron la postura con huevos de menor peso, pero con similar regularidad y uniformidad, presentando (b) mayor longitud del tarso y del fémur en ambas edades, mayor diámetro del tarso a las 30 semanas y mayor longitud de la tibia a las 71 semanas de edad (c) mayor tasa de crecimiento exponencial entre la sexta y la vigésima semana pero similar patrón de crecimiento global, (d) menor peso asintótico del huevo, menor tasa de maduración para el carácter y menor peso teórico del primer huevo y (e) mayor número de huevos de menor peso y similar relación de conversión entre las 26 y 35 semanas. La combinación del tamaño de los ornamentos sexuales se presenta como una alternativa para la selección temprana de los reproductores

Productive traits in hybrid hens with Fayoumi maternal genotype

The productive performance during the first laying cycle of two experimental F1 populations of laying hens with Fayoumi maternal genotype and either Rhode Island Red or White Leghorn paternal genotype was evaluated. The Egyptian Fayoumi breed characterized by a low body weight was used to explore its usefulness as a parent stock to diminish maintenance costs of the progeny by reducing its mean body weight. Productive traits at sexual maturity, body weight and egg weight dynamics, form and shape of the egg, feed efficiency for egg production and major egg components were studied. No clear advantage of either of the two hybrids with Fayoumi genotype was evinced. The expectations of enhancing feed efficiency were not accomplished. Although F1 hens were lighter than both paternal lines, their voluntary feed consumption equaled that of the heaviest birds. This fact could be explained in terms of a behavioural response to environmental temperature as these birds, with a natural resistance to hot climates, showed a higher daily intake relative to their body weight when reared during the winter season in a temperate zone

Phase Structure and Compactness

In order to study the influence of compactness on low-energy properties, we compare the phase structures of the compact and non-compact two-dimensional multi-frequency sine-Gordon models. It is shown that the high-energy scaling of the compact and non-compact models coincides, but their low-energy behaviors differ. The critical frequency $\beta^2 = 8\pi$ at which the sine-Gordon model undergoes a topological phase transition is found to be unaffected by the compactness of the field since it is determined by high-energy scaling laws. However, the compact two-frequency sine-Gordon model has first and second order phase transitions determined by the low-energy scaling: we show that these are absent in the non-compact model.Comment: 21 pages, 5 figures, minor changes, final version, accepted for publication in JHE

Nonperturbative renormalization group approach to frustrated magnets

This article is devoted to the study of the critical properties of classical XY and Heisenberg frustrated magnets in three dimensions. We first analyze the experimental and numerical situations. We show that the unusual behaviors encountered in these systems, typically nonuniversal scaling, are hardly compatible with the hypothesis of a second order phase transition. We then review the various perturbative and early nonperturbative approaches used to investigate these systems. We argue that none of them provides a completely satisfactory description of the three-dimensional critical behavior. We then recall the principles of the nonperturbative approach - the effective average action method - that we have used to investigate the physics of frustrated magnets. First, we recall the treatment of the unfrustrated - O(N) - case with this method. This allows to introduce its technical aspects. Then, we show how this method unables to clarify most of the problems encountered in the previous theoretical descriptions of frustrated magnets. Firstly, we get an explanation of the long-standing mismatch between different perturbative approaches which consists in a nonperturbative mechanism of annihilation of fixed points between two and three dimensions. Secondly, we get a coherent picture of the physics of frustrated magnets in qualitative and (semi-) quantitative agreement with the numerical and experimental results. The central feature that emerges from our approach is the existence of scaling behaviors without fixed or pseudo-fixed point and that relies on a slowing-down of the renormalization group flow in a whole region in the coupling constants space. This phenomenon allows to explain the occurence of generic weak first order behaviors and to understand the absence of universality in the critical behavior of frustrated magnets.Comment: 58 pages, 15 PS figure

Stem rust resistance in wheat is suppressed by a subunit of the mediator complex

Stem rust is an important disease of wheat that can be controlled using resistance genes. The gene SuSr-D1 identified in cultivar 'Canthatch' suppresses stem rust resistance. SuSr-D1 mutants are resistant to several races of stem rust that are virulent on wild-type plants. Here we identify SuSr-D1 by sequencing flow-sorted chromosomes, mutagenesis, and map-based cloning. The gene encodes Med15, a subunit of the Mediator Complex, a conserved protein complex in eukaryotes that regulates expression of protein-coding genes. Nonsense mutations in Med15b.D result in expression of stem rust resistance. Time-course RNAseq analysis show a significant reduction or complete loss of differential gene expression at 24h post inoculation in med15b.D mutants, suggesting that transcriptional reprogramming at this time point is not required for immunity to stem rust. Suppression is a common phenomenon and this study provides novel insight into suppression of rust resistance in wheat. Stem rust is an important disease of wheat and resistance present in some cultivars can be suppressed by the SuSr-D1 locus. Here the authors show that SuSr-D1 encodes a subunit of the Mediator Complex and that nonsense mutations are sufficient to abolish suppression and confer stem rust resistance

Epidemiology, practice of ventilation and outcome for patients at increased risk of postoperative pulmonary complications

BACKGROUND Limited information exists about the epidemiology and outcome of surgical patients at increased risk of postoperative pulmonary complications (PPCs), and how intraoperative ventilation was managed in these patients. OBJECTIVES To determine the incidence of surgical patients at increased risk of PPCs, and to compare the intraoperative ventilation management and postoperative outcomes with patients at low risk of PPCs. DESIGN This was a prospective international 1-week observational study using the ‘Assess Respiratory Risk in Surgical Patients in Catalonia risk score’ (ARISCAT score) for PPC for risk stratification. PATIENTS AND SETTING Adult patients requiring intraoperative ventilation during general anaesthesia for surgery in 146 hospitals across 29 countries. MAIN OUTCOME MEASURES The primary outcome was the incidence of patients at increased risk of PPCs based on the ARISCAT score. Secondary outcomes included intraoperative ventilatory management and clinical outcomes. RESULTS A total of 9864 patients fulfilled the inclusion criteria. The incidence of patients at increased risk was 28.4%. The most frequently chosen tidal volume (VT) size was 500 ml, or 7 to 9 ml kg1 predicted body weight, slightly lower in patients at increased risk of PPCs. Levels of positive end-expiratory pressure (PEEP) were slightly higher in patients at increased risk of PPCs, with 14.3% receiving more than 5 cmH2O PEEP compared with 7.6% in patients at low risk of PPCs (P < 0.001). Patients with a predicted preoperative increased risk of PPCs developed PPCs more frequently: 19 versus 7%, relative risk (RR) 3.16 (95% confidence interval 2.76 to 3.61), P < 0.001) and had longer hospital stays. The only ventilatory factor associated with the occurrence of PPCs was the peak pressure. CONCLUSION The incidence of patients with a predicted increased risk of PPCs is high. A large proportion of patients receive high VT and low PEEP levels. PPCs occur frequently in patients at increased risk, with worse clinical outcome