Cambios de la alimentación en Cunicultura en las últimas décadas y perspectivas de futuro

Este trabajo resume estudios e investigaciones relacionados a la definición de las recomendaciones nutricionales utilizadas en la alimentación para la producción intensiva de carne de conejo. La fibra es el principal constituyente químico en la dieta de conejos, que típicamente contiene de 320 a 360 y de 50 a 90 g / kg de fibra insoluble y soluble, respectivamente. En cambio, el contenido en la dieta de granos de cereal (~ 120 a 160 g / kg), de grasa (15 a 25 g / kg) y de concentrados de proteína (150 a 180 g / kg) son usualmente bajos respecto a la crianza intensiva de otras especies de monogástricos. Los conejos no digieren bien los constituyentes de la pared celular, pero este efecto es compensado por la motilidad del intestino, el cual incrementa el paso de la digesta, y permite lograr un consumo mayor de materia seca. Un mayor consumo de alimento y un balance adecuado de nutrientes es el requerimiento para sostener la elevada necesidad de las medidas en conejos de alta productividad, como lo son los parámetros reproductivos, la producción de leche o el índice de crecimiento durante el periodo de cebo. Durante el destete, ocurren patologías en un contexto de desarrollo incompleto de la fisiología digestiva en gazapos. La administración de dietas balanceadas están también relacionadas con la revención de desordenes por medio de tres mecanismos: (i) promover un menor tiempo de retención de la digesta en el tracto digestivo por la alimentación con fuentes de fibra con características químicas y físicas optimas, (ii) restringir el consumo de alimento luego del destete o (iii) causando un menor flujo de sustratos fácilmente disponibles en la zona de fermentación, por una modificación en la dieta (e.g. disminuyendo el contenido de proteína y almidón, aumentando la digestibilidad o sustituyendo parte de la fibra insoluble con fibra soluble), o retrasando la edad del destete. La alteración en la composición de la microbiota intestinal es postulada como una de las principales causas de estas patologías

Effect of early feed restriction on performance and health status in growing rabbits slaughtered at 2 kg live-weight

[EN] The effect of a time-limited access to the feeders (8 h per d from 9:30 to 17:30) on fattening performance and health status was studied in rabbits reared until 2 kg live-weight as typical in the Spanish market. For this purpose, the same diet (10.5 MJ digestible energy/kg, 38.9% neutral detergent fibre and 18.4% crude protein on dry matter basis) was used over two consecutive trials. A total of 192 growing rabbits (96 in each trial) were weaned at 35 d and assigned to 2 different feeding treatments (continuously fed ad libitum or restricted from 35 until 49 d). In the first trial, feed restriction reduced daily feed intake (94.3 vs. 74.2 g; P<0.001), daily weight gain (43.6 vs. 27.1 g; P<0.001) and impaired feed conversion rate (FCR) (2.28 vs. 2.92, P<0.001) in the first 14 d after weaning. Later on, no feed restriction was applied and a compensatory growth was observed in previously restricted rabbits (44.8 vs. 54.8 g/d; P<0.001). Early restricted rabbits did not reach the Spanish commercial weight (2 kg) at 63 d of age and weighed less than full-fed rabbits (1989 vs. 1888 g; P=0.001). Moreover, feed restriction did not improve FCR in the whole fattening period (2.56 on average). The second trial was extended until 70 d to permit restricted rabbits to attain market weight. However, at that age, live weight of restricted rabbits was also lower than that of rabbits always fed ad libitum (2285 vs. 2101 g; P=0.001). In the first trial, no health problem was recorded (average mortality 1.04%) whereas in the second trial feed restriction allowed both mortality (25.6 vs. 6.34%, P=0.017) and morbidity (41.4 vs. 12.7%, P=0.004) to decrease. The higher number of losses in the second trial made economic FCR differ from scientific FCR (3.63 vs. 2.89, on average) in the 35¿70 d period. Moreover, morbidity increased heterogeneity of fattening performance. In conclusion, the interest of feed restriction in Spanish fattening rabbit farms is mitigated by the conventional market weight. Nevertheless, in a context with high rates of digestive troubles, a time-limited access to the feeder enhances health status on the farm and could justify the short delay necessary to reach slaughter weight.Romero, C.; Cuesta, S.; Astillero, J.; Nicodemus, N.; Blas, CD. (2010). Effect of early feed restriction on performance and health status in growing rabbits slaughtered at 2 kg live-weight. World Rabbit Science. 18(4):211-218. doi:10.4995/wrs.2010.77821121818

Treatment of psoriasis with anti-IL17

La psoriasis es una enfermedad inflamatoria crónica de origen inmune que afecta principalmente a la piel y con un tratamiento a largo plazo. Existen multitud de tratamientos disponibles para su enfermedad como fármacos biológicos (como anti-TNF o anti-IL-17). El descubrimiento de la participación de los linfocitos Th17 y la interleucina 17 en la patogenia de la psoriasis ha abierto la posibilidad de manejar esta enfermedad con fármacos contra esa interleucina (secukinumab, ixekizumab) o su receptor (brodalumab). El manejo terapeútico de la psoriasis es complejo. La indicación de terapias biológicas se establece en los casos de psoriasis moderada severa establecida por según los índices de severidad de la psoriasis (BSA o el PASI) o de afectación de la calidad de vida (DLQI) o por la ausencia de respuesta a otras terapias sistémicas. En este TI-TFGM se plantea una visión del tratamiento de la psoriasis, prestando especial atención en el tratamiento con anti-IL17, valorando la utilidad de estos fármacos en pacientes con psoriasis moderada-grave del Área Integrada de Guadalajara, la supervivencia y la posible asociación a diferentes comorbilidades como el síndrome metabólico.Psoriasis is a chronic inflammatory disease of immune origin that mainly affects the skin and requires long-term treatment. There are many treatments currently available for the management of this disease, like biological drugs (such as anti-TNF or anti-IL-17). The discovery of the participation of Th17 lymphocytes in the pathogenesis of psoriasis and interleukin 17 has opened the possibility of managing this disease with drugs against said interleukin (secukinumab, ixekizumab) or its receptor (brodalumab). The therapeutic management of psoriasis is complex. The indication for biological therapies is established in cases of moderate to severe psoriasis established by the severity indexes of psoriasis (BSA or PASI) or quality of life impairment (DLQI) or in the absence of response to other systemic therapies This TI-TFGM presents a vision of psoriasis treatment, paying special attention to anti IL17 treatment, assessing the usefulness of these drugs in patients with moderate-severe psoriasis in the Guadalajara Integrated Area; the survival and possible association to different comorbidities such as metabolic syndromeGrado en Medicin

Zn(II), Cd(II) and Pb(II) complexation with pyridinecarboxylate containing ligands

[Abstract] Herein, we report the coordination properties towards Zn(II), Cd(II) and Pb(II) of two hexadentate ligands containing pyridinecarboxylate groups with ethane-1,2-diamine (bcpe) or cyclohexane-1,2-diamine (bcpc) backbones. The X-ray crystal structures of [Zn(bcpe)], [Cd(bcpe)] and [Cd(bcpc)] show hexadentate binding of the ligand to the metal ions, with the coordination polyhedron being best described as a severely distorted octahedron. The X-ray crystal structure of the Pb(II) analogue shows the presence of tetrameric structural units [Pb4(bcpe)4] in which the four Pb(II) ions are bridged by carboxylate oxygen atoms. While in the Zn(II) and Cd(II) complexes the bcpe ligand adopts a twist–wrap (tw) conformation in which the ligand wraps around the metal ion by twisting the pyridyl units relative to each other, for the Pb(II) complex a twist–fold (tf) conformation, where a slight twisting of the pyridyl units is accompanied by an overall folding of the two pyridine units relative to each other is observed. Theoretical calculations performed at the DFT (B3LYP) level on the [Pb(bcpe)] and [Pb(bcpc)] systems indicate that the tf conformation is more stable than the tw form both in the solid state and in aqueous solution. The analysis of the natural bond orbitals (NBOs) indicate that the Pb(II) lone-pair is polarized by a substantial 6p contribution, which results in a hemi-directed coordination geometry around the metal ion. Potentiometric studies have been carried out to determine the protonation constants of the ligands and the stability constants of the complexes with Zn(II), Cd(II), Pb(II) and Ca(II). The replacement of the ethylene backbone of bcpe by a cyclohexylene ring causes a very important increase in the stability constant of the Pb(II) complex (ca. 2.3 logK units), while this effect is less important for Cd(II) (ca. 1.4 logK units). However, the introduction of the cyclohexylene ring does not substantially affect the stability of the Zn(II) and Ca(II) complexes. The ligand bcpc shows Pb/Ca and Cd/Ca selectivities [108.9 and 109.8, respectively] superior to those of extracting agents, such as EDTA, already used in Pb(II) and Cd(II) removal from contaminated water and soils.Galicia. Consellería de Innovación, Industria e Comercio; PGIDIT06TAM10301P

Understanding stability trends along the lanthanide series

[Abstract] The stability trends across the lanthanide series of complexes with the polyaminocarboxylate ligands TETA4− (H4TETA=2,2′,2′′,2′′′‐(1,4,8,11 tetraazacyclotetradecane‐1,4,8,11‐tetrayl)tetraacetic acid), BCAED4− (H4BCAED=2,2′,2′′,2′′′ {[(1,4‐diazepane‐1,4‐diyl)bis(ethane‐2,1‐diyl)]bis(azanetriyl)}tetraacetic acid), and BP18C62− (H2BP18C6=6,6′‐[(1,4,10,13‐tetraoxa‐7,16‐diazacyclooctadecane‐7,16 diyl)bis(methylene)]dipicolinic acid) were investigated using DFT calculations. Geometry optimizations performed at the TPSSh/6‐31G(d,p) level, and using a 46+4fn ECP for lanthanides, provide bond lengths of the metal coordination environments in good agreement with the experimental values observed in the X‐ray structures. The contractions of the Ln3+ coordination spheres follow quadratic trends, as observed previously for different isostructural series of complexes. We show here that the parameters obtained from the quantitative analysis of these data can be used to rationalize the observed stability trends across the 4f period. The stability trends along the lanthanide series were also evaluated by calculating the free energy for the reaction [La(L)]n+/−(sol)+Ln3+(sol)→[Ln(L)]n+/ (sol)+La3+(sol). A parameterization of the Ln3+ radii was performed by minimizing the differences between experimental and calculated standard hydration free energies. The calculated stability trends are in good agreement with the experimental stability constants, which increase markedly across the series for BCAED4−complexes, increase smoothly for the TETA4− analogues, and decrease in the case of BP18C62− complexes. The resulting stability trend is the result of a subtle balance between the increased binding energies of the ligand across the lanthanide series, which contribute to an increasing complex stability, and the increase in the absolute values of hydration energies along the 4f period.Xunta de Galicia; CN2012/01

Managing variability in decision making in swine growing-finishing units

peer-reviewedAnalysis of data collected from pig farms may be useful to understand factors affecting pig health and productive performance. However, obtaining these data and drawing conclusions from them can be done at different levels and presents several challenges. In the present study, information from 688 batches of growing-finishing (GF) pigs (average initial and final body weight of 19.1 and 108.5 kg respectively) from 404 GF farms integrated in 7 companies was obtained between July 2008 and July 2010 in Spain by survey. Management and facility factors associated with feed conversion ratio (FCR) and mortality were studied by multiple linear regression analysis in each single company (A to G) and in an overall database (OD). Factors studied were geographic location of the farm, trimester the pigs entered the farm, breed of sire and sex segregation in pens (BREGENSEG), use of circovirus vaccine, number of origins the pigs were obtained from, age of the farm, percentage of slatted floor, type of feeder, drinker and ventilation, number of phases and form of feed, antibiotic administration system, water source, and number and initial weight of pigs. Results In two or more companies studied and/or in OD, the trimester when pigs were placed in the farm, BREGENSEG, number of origins of the pigs, age of the farm and initial body weight were factors associated with FCR. Regarding mortality, trimester of placement, number of origins of the pigs, water source in the farm, number of pigs placed and the initial body weight were relevant factors. Age of the farm, antibiotic administration system, and water source were only provided by some of the studied companies and were not included in the OD model, however, when analyzed in particular companies these three variables had an important effect and may be variables of interest in companies that do not record them. Conclusions Analysing data collected from farms at different levels helps better understand factors associated with productive performance of pig herds. Out of the studied factors trimester of placement and number of origins of the pigs were the most relevant factors associated with FCR and mortality.This research was supported by the Spanish Ministerio de Ciencia e Innovación (project AGL2011-29960). We also thank the Agencia Española de Cooperación Internacional para el Desarrollo (MAEC-AECID) for research fellowship

Binuclear Co(II), Ni(II), Cu(II) and Zn(II) complexes with Schiff-bases derived from crown ether platforms: rare examples of ether oxygen atoms bridging metal centers

[Abstract] Bibracchial lariat ethers L3 and L4, derived from the condensation of N,N′-bis(2-aminobenzyl)-1,10-diaza-15-crown-5 or N,N′-bis(2-aminobenzyl)-4,13-diaza-18-crown-6 with salicylaldehyde, form binuclear complexes with Co(II), Ni(II), Cu(II) and Zn(II). Our studies show that the different denticity and crown moiety size of the two related receptors give rise to important differences on the structures of the corresponding complexes. Single crystal X-ray diffraction analysis shows that the [Ni2(L3)(H2O)2]2+ and [Cu2(L3)(NO3)]+ complexes constitute a rare example in which an oxygen atom of the crown moiety is bridging the two six coordinate metal ions. In contrast, none of the oxygen atoms of the crown moiety is acting as a bridging donor atom in the [Co2(L4)(CH3CN)2]2+, [Cu2(L4)]2+ and [Zn2(L4)]2+ complexes. This is attributed to the larger size the crown moiety and the higher denticity of L4 compared to L3. In [Co2(L4)(CH3CN)2]2+ the metal ions show a distorted octahedral coordination, while in the Cu(II) and Zn(II) analogues the metal ions are five-coordinated in a distorted trigonal bipyramidal environment. In [Cu2(L3)(NO3)]+ the coordinated nitrate anion acts as a bidentate bridging ligand, which results in the formation of a 1D coordination polymer.Xunta de Galicia; INCITE09E1R103013E

Cinderella Elements: Strategies to Increase the Stability of Group 1 Complexes by Tailoring Crown Macrocycles

[Abstract] The synthesis and structural characterization of six sodium complexes with bibracchial lariatethers containing aniline or benzimidazole side arms, and derived from 1,7 diaza-12-crown-4, 1,10-diaza-15-crown-5 or 4,13-diaza-18-crown-6, are reported. The X-ray structures of four of these compounds have been obtained. Additionally, the X-ray structures of a sodium macrobicyclic complex derived from 1,10-diaza-15-crown-5, and a potassium complex with a bibracchial lariat ether containing aniline side arms are also reported. Bonding distances as well as the stability constants in acetonitrile solution confirm that the coordination of the pendant arms provides an important contribution to the overall stability of the complexes, particularly when benzimidazole pendants are present rending more stable complexes, even more than cryptand complexes of the same size. Compared with the parent crown ethers, the stability increases when the side arms contain benzimidazole moieties but remains about the same order when aniline side arms are present.Xunta de Galicia; CN2012/01