Modelación del crecimiento de pollos de engorda criados en pastoreo o confinamiento

Objective: To evaluate the growth of pasture or confinement-raised broiler chickens, using the Gompertz, Logistic and Richards models, and identify the most appropriate. Methodology: One hundred ten straight-run broilers Ross 308 were distributed in two systems: pasture or confinement. Birds were weighed every week until 56 d of age. Three growth models (Gompertz, Logistic and Richards) were considered and compared based on three goodness of fit criteria (coefficient of determination, Akaike information criterion and Bayesian information criterion). Results: The initial (L) and exponential (K) growth rates of the Gompertz and Logistic models, respectively, were higher in confined birds (L = 0.1232, K = 0.0779) compared to those raised in pasture (L = 0.0944 , K = 0.0657). The maximum relative growth (K) of the Richards model was lower in chickens in confinement (0.0129) than in pasture system (0.0153). With the three models, higher asymptotic weights (WA) were estimated for confined chickens (3,967.1 to 9,095.5) compared to pasture birds (2,461.7 to 5,192.6). According to the criteria considered, the Richards model had the best fit. Implications of study: The results are only valid for straight-run Ross 308 broiler chickens and under the specified management conditions. Findings: The growth of pasture or confinement-raised broiler chickens can be described with the Gompertz, Logistic and Richards models, however, the latter has a better fit.Objetivo: Evaluar el crecimiento de pollos de engorda criados en pastoreo o confinamiento, mediante los modelos Gompertz, Logístico y Richards, e identificar el más adecuado. Metodología: Ciento diez pollos de engorda mixtos Ross 308 se distribuyeron en dos sistemas de crianza: pastoreo o confinamiento. Semanalmente se obtuvo el peso corporal de cada ave, hasta los 56 d de edad. Tres modelos de crecimiento (Gompertz, Logístico y Richards) fueron considerados y se compararon con base en tres criterios de bondad de ajuste (coeficiente de determinación, criterio de información de Akaike y criterio de información Bayesiano). Resultados: Las tasas de crecimiento inicial (L) y exponencial (K) de los modelos Gompertz y Logístico, respectivamente, fueron mayores en las aves en confinamiento (L = 0.1232, K = 0.0779) respecto a las criadas en pastoreo (L = 0.0944, K = 0.0657). El máximo crecimiento relativo (K) del modelo Richards fue menor en pollos en confinamiento (0.0129) que en pastoreo (0.0153). Con los tres modelos, se estimaron mayores pesos asintóticos (WA) para los pollos en confinamiento (3,967.1 a 9,095.5) respecto a las aves en pastoreo (2,461.7 a 5,192.6). De acuerdo a los criterios considerados, el modelo Richards es el que tiene un mejor ajuste.         Implicaciones del estudio: Los resultados obtenidos sólo son válidos para pollos de engorda mixtos Ross 308 y bajo las condiciones de manejo especificadas. Conclusión: El crecimiento de pollos de engorda criados en confinamiento o pastoreo, puede describirse con los modelos Gompertz, Logístico y Richards, sin embargo, este último tiene un mejor ajuste

Análisis de crecimiento del pasto maralfalfa (Pennisetum sp.) en clima cálido subhúmedo

The objective of this experiment was to conduct growth analysis on “Maralfalfa” grass (Pennisetum sp.) from plantingto determine the optimal time to harvest. The plant morphology (MP), growth rate (TC), height, radiation interception(RI),  leaf  /  stem  ratio  (H:T),  leaf/no  leaf  (H:  NH)  and  the  biomass  accumulation,  were  evaluated  at intervals  of15  d  during  a  180  d  period,  except  for  the  first  two  samples  that  were  sampled  monthly.  Data  were  analyzedusing  the  GLM  procedure  of  SAS,  under  an  experimental  design  of  randomized  blocks,  with  repeated  measuresover  time,  with  three  replicates.  The  MP  varied  significantly  (P<0.01)  across  different  physiological  states.  Themaximum  biomass  production  and  CT  was  reached  at  151  d  after  planting  with  37,297  kg  DM  ha-1  and  247  kgDM  ha-1  d-1,  respectively.  It  also,  recorded  the  highest  percentage  of  RI  (97.4),  with  a  height  of  2.3  m,approximately.  Biomass  production  of  stems  and  dead  material  production  Maralfalfa  grass  are  correlatedpositively  with  the  increasing  age  of  the  plant.  The  maximum  growth  rate  coincides  with  the  maximum productionof  leaves  and  stems  and  increased  production  of  total  biomass.El objetivo de este experimento fue realizar un análisis de crecimiento del pasto “Maralfalfa” (Pennisetum sp.) desde la siembra hasta determinar el momento óptimo de cosecha. La morfología de la planta (MP), tasa decrecimiento (TC), altura, radiación interceptada (RI), relación hoja/tallo (H:T), hoja/no hoja (H:NH) y la acumulación de biomasa aérea, se evaluaron a intervalos de 15 días, en un periodo de 180 días, a excepción de los dos primeros muestreos que fueron mensuales. Los datos se analizaron mediante el procedimiento GLM de SAS, bajo un diseño experimental de bloques al azar, con medidas repetidas en el tiempo, con tres repeticiones. La MP varió de manera significativa (P<0.01) a través de los diferentes estados fisiológicos. La máxima producción de biomasa aérea y TC se alcanzó a los 151 días después de la siembra con 37,297 kg MS ha-1 y 247 kg MS ha-1 d-1, respectivamente. También se registró el mayor porcentaje de RI (97.4 %), con una altura de 2.3 m aproximadamente. La producción de biomasa de tallos y la producción de material muerto del pasto maralfalfa, están correlacionadas de manera positiva con el incremento en la edad de la planta. La máxima tasa decrecimiento, coincide con la máxima producción de hojas y de tallos, y con la mayor producción de biomasa total

Chemical composition of Taiwan grass (Pennisetum purpureum Schum.) at different harvesting intervals

Objective: To evaluate the effect of the harvesting interval on the quality of Taiwan grass (Pennisetum purpureum Schum.). Design/Methodology/Approximation: Crude protein (CP), in vitro dry matter digestibility (IVDMD), crude fiber (CF), neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin, ether extract, and ashes were determined. Samples were collected from the Papaloapan experimental site of the Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias, Isla, State of Veracruz (18° 01’ 45’’ N, 95° 31’ 35’’ W). Treatments consisted of five harvesting intervals (30, 60, 90, 120, and 150 days). Data were analyzed under the general linear model and means were separated using Tukey’s test (P&lt;0.05). Results: The nutritional value decreased (P&lt;0.05) as the harvesting interval increased from 30 to 150 days. The following elements decreased: CP (leaves, from 12.3 to 3.7%; stems, from 8.9 to 2.1%), IVDMD (leaves, from 66.5 to 43.5%; stems, from 62.7 to 32.5%), ether extract (leaves, from 2.4 to 1.4%; stems, from 1.4 to 0.6%), and ashes (leaves, from 10.3 to 6.1%; stems, from 10.9 to 2.9%). On the contrary, the following elements increased: CF (leaves, from 28.4 to 41.1%; stems, from 33.4 to 44.5%), NDF (leaves, from 60.4 to 72.5%; stems, from 63.8 to 74.3%), ADF (leaves, from 36.7 to 46.8%; stems, from 34.6 to 50.7%), and lignin (leaves, from 9.7 to 15.3%; stems, from 11.0 to 18.3%). Study Limitations/Implications: Neither ˂30 days harvesting intervals nor yields (tons) per hectare were taken into account. Findings/Conclusions: Taiwan grass should be harvested at 60 days, when its nutritional value has not decreased too much

Effect of <i>Brosimum alicastrum</i> Foliage on Intake, Kinetics of Fermentation and Passage and Microbial N Supply in Sheep Fed <i>Megathyrsus maximus</i> Hay

An experiment was carried out to assess the effect of the incorporation of sun-dried foliage of Brosimum alicastrum into rations based on hay of Megathyrsus maximus on intake, rumen fermentation, kinetics of passage, microbial nitrogen supply to the small intestine, apparent digestibility in Pelibuey hair sheep. Four rations were randomly allotted to four rumen-cannulated lambs (BW = 37.4 ± 4.9 kg) using a 4 × 4 Latin square design to assess the effect of increasing levels (0, 15, 30 and 45% DM basis) of foliage of Brosimum alicastrum on a basal ration of M. maximus. Organic matter intake and water consumption increased linearly (p B. alicastrum in the ration. The rate and potential extent of rumen fermentation of OM and CP of B. alicastrum were 10.6%/h and 86.6% and 11.4%/h and 95.2%, respectively, but no effect (p > 0.05) was found on the potential rumen degradation of DM (40.2%) or on the rate of degradation of DM (0.033%/h) of M. maximus, although a positive effect was found in the rumen degradation rate of NDF (p k1) increased linearly (p B. alicastrum. Rumen pH was not affected by the incorporation of B. alicastrum (p > 0.05). Microbial nitrogen supply to the small intestine (p p p B. alicastrum foliage. Results from this experiment suggest that the foliage of Brosimum alicastrum can be readily incorporated at around 30% of the ration of dry matter in hair sheep with beneficial effects on feed intake, rate of passage and microbial N supply to the lower tract

Clones de nopal Oreja de Elefante Mexicana con potencial forrajero

Evaluar clones del cultivar de nopal Oreja de Elefante Mexicana (Opuntia stricta Haw),conelobjetivo de encontrar elque mostraracaracterísticas agronómicas y zootécnicas para ser considerado con potencial forrajero, se llevó a cabo un experimento en el Instituto Agronómico de Pernambuco (IPA), localizado en las coordenadas 08° 25’15’’ latitud sur y 37° 03’41’’longitud oeste, a 663 msnm, con una precipitación de 692 mm. El periodo experimental comprendió de enero 2014 a julio de 2015 y los clones utilizados fueron Lisa 1, Lisa 2, Seg CV, Planta mãe, Seg 1, Seg 2, Seg 3, Seg 4, Seg 5 y Seg 6. Las variables evaluadas fueron producción(t MS ha-1), número de cladodios en planta (NC), altura de la planta (AP), ancho de la planta (ANP), cantidad de espina (CE), tamaño de espina (TE) y cantidad de gloquidio (CG); dentro de cada planta se midió en cladodios, perímetro (P), longitud (LC),ancho (ANC) y grosor (GC), número de líneas (LCP) y número de yemas (YCP). El diseño experimental fue completamente al azar y la prueba de comparación de medias con Tukey (p0.05). Se presentaron diferencias entre clones (p≤ 0.05) lisa 2, mostró la menor CE, TE, CG, y la menor producción(6.45 t MS ha-1), el clon Seg CV, presentó mayor producción(67.41 t MS ha-1), NC, AP, y ANP;sin embargo, también presentó mayor CE, TE y CG por lo que pese a su rendimientono muestra las mejores características agronómicas y zootécnicasEvaluar clones del cultivar de nopal Oreja de Elefante Mexicana (Opuntia stricta Haw), con el objetivo de encontrar el que mostrara características agronómicas y zootécnicas para ser considerado con potencial forrajero, se llevó a cabo un experimento en el Instituto Agronómico de Pernambuco (IPA), localizado en las coordenadas 08° 25’ 15’’ latitud sur y 37° 03’ 41’’ longitud oeste, a 663 msnm, con una precipitación de 692 mm. El periodo experimental comprendió de enero 2014 a julio de 2015 y los clones utilizados fueron Lisa 1, Lisa 2, Seg CV, Planta mãe, Seg 1, Seg 2, Seg 3, Seg 4, Seg 5 y Seg 6. Las variables evaluadas fueron producción (t MS ha-1), número de cladodios en planta (NC), altura de la planta (AP), ancho de la planta (ANP), cantidad de espina (CE), tamaño de espina (TE) y cantidad de gloquidio (CG); dentro de cada planta se midió en cladodios, perímetro (P), longitud (LC), ancho (ANC) y grosor (GC), número de líneas (LCP) y número de yemas (YCP). El diseño experimental fue completamente al azar y la prueba de comparación de medias con Tukey (p 0.05). Se presentaron diferencias entre clones (p≤ 0.05) lisa 2, mostró la menor CE, TE, CG, y la menor producción (6.45 t MS ha-1), el clon Seg CV, presentó mayor producción (67.41 t MS ha-1), NC, AP, y ANP; sin embargo, también presentó mayor CE, TE y CG por lo que pese a su rendimiento no muestra las mejores características agronómicas y zootécnicas

Reduction of Enteric Methane Emissions in Heifers Fed Tropical Grass-Based Rations Supplemented with Palm Oil

Vegetable oils have been shown to reduce enteric methane (CH4) production by up to 20%. However, when the level of incorporation exceeds the threshold of 70 g/kg DM, dry matter intake (DMI) and nutrient digestibility may be reduced. The objective of this study was to determine the effects of the incorporation of three levels of palm oil (PO) on enteric CH4 emissions, rumen fermentation and apparent digestibility in heifers fed low-quality grass. Four rumen-cannulated heifers (Bos taurus &times; Bos indicus) were randomly assigned to four treatments: control (CON) and three increasing PO levels: 20, 40 and 60 g/kg in a 4 &times; 4 Latin square design with four periods of 22 days (14 days of adaptation to the ration), 5 days of feces and rumen fluid sampling (day 18, 4 h postprandial) and the last 3 days for measurements of CH4 in respiration chambers. With the exception of CP (p = 0.04), starch (p = 0.002) and EE (p &lt; 0.001), the intake of nutrients was not affected by the inclusion of PO (p &gt; 0.05). The apparent digestibility (AD) of nutrients was not affected by the inclusion of PO (p &gt; 0.05), except for starch, which reduced its AD as the PO level was increased (p &lt; 0.05). The gross energy intake was higher in PO-containing rations (p = 0.001), on the other hand, the digestible energy intake was similar between treatments (p &gt; 0.05). In situ ruminal digestion kinetics and the potential degradability remained unchanged (p &gt; 0.05), however, the effective degradability decreased with the inclusion of PO in the rations (p &lt; 0.05). The ruminal pH and molar proportions of acetic, isovaleric and valeric acid were not different between treatments (p &gt; 0.05). The ruminal concentration of propionic acid increased as the PO level increased, reaching its highest molar proportion with 60 g/kg PO (p &lt; 0.05), however, the acetic/propionic ratio and the molar proportions of butyric acid and isobutyric acid decreased as the PO level increased (p &lt; 0.05). The total daily CH4 production was lower in diets containing 20, 40 and 60 g/kg PO compared to the CON diet (p &lt; 0.001). The production of CH4 per kg DMI and DOMI was greater (p &lt; 0.05) for the CON diet compared to all three rations containing PO. The emission intensity, Ym, energy lost as CH4, emission factor (EF) and kg CO2 eq/year were reduced as an effect of the inclusion of PO (p &lt; 0.05). Based on the results obtained, it is concluded that the incorporation of PO in cattle rations has the potential to reduce enteric methane emissions by 4% for every 10 g/kg PO in the ration, without affecting DMI, apparent digestibility or the consumption of digestible nutrient fractions

Reduction of Enteric Methane Emissions in Heifers Fed Tropical Grass-Based Rations Supplemented with Palm Oil

Vegetable oils have been shown to reduce enteric methane (CH4) production by up to 20%. However, when the level of incorporation exceeds the threshold of 70 g/kg DM, dry matter intake (DMI) and nutrient digestibility may be reduced. The objective of this study was to determine the effects of the incorporation of three levels of palm oil (PO) on enteric CH4 emissions, rumen fermentation and apparent digestibility in heifers fed low-quality grass. Four rumen-cannulated heifers (Bos taurus × Bos indicus) were randomly assigned to four treatments: control (CON) and three increasing PO levels: 20, 40 and 60 g/kg in a 4 × 4 Latin square design with four periods of 22 days (14 days of adaptation to the ration), 5 days of feces and rumen fluid sampling (day 18, 4 h postprandial) and the last 3 days for measurements of CH4 in respiration chambers. With the exception of CP (p = 0.04), starch (p = 0.002) and EE (p p > 0.05). The apparent digestibility (AD) of nutrients was not affected by the inclusion of PO (p > 0.05), except for starch, which reduced its AD as the PO level was increased (p p = 0.001), on the other hand, the digestible energy intake was similar between treatments (p > 0.05). In situ ruminal digestion kinetics and the potential degradability remained unchanged (p > 0.05), however, the effective degradability decreased with the inclusion of PO in the rations (p p > 0.05). The ruminal concentration of propionic acid increased as the PO level increased, reaching its highest molar proportion with 60 g/kg PO (p p 4 production was lower in diets containing 20, 40 and 60 g/kg PO compared to the CON diet (p 4 per kg DMI and DOMI was greater (p m, energy lost as CH4, emission factor (EF) and kg CO2 eq/year were reduced as an effect of the inclusion of PO (p < 0.05). Based on the results obtained, it is concluded that the incorporation of PO in cattle rations has the potential to reduce enteric methane emissions by 4% for every 10 g/kg PO in the ration, without affecting DMI, apparent digestibility or the consumption of digestible nutrient fractions

Prosthetic Valve Candida spp. Endocarditis: New Insights Into Long-term Prognosis—The ESCAPE Study

International audienceBackground: Prosthetic valve endocarditis caused by Candida spp. (PVE-C) is rare and devastating, with international guidelines based on expert recommendations supporting the combination of surgery and subsequent azole treatment.Methods: We retrospectively analyzed PVE-C cases collected in Spain and France between 2001 and 2015, with a focus on management and outcome.Results: Forty-six cases were followed up for a median of 9 months. Twenty-two patients (48%) had a history of endocarditis, 30 cases (65%) were nosocomial or healthcare related, and 9 (20%) patients were intravenous drug users. "Induction" therapy consisted mainly of liposomal amphotericin B (L-amB)-based (n = 21) or echinocandin-based therapy (n = 13). Overall, 19 patients (41%) were operated on. Patients <66 years old and without cardiac failure were more likely to undergo cardiac surgery (adjusted odds ratios [aORs], 6.80 [95% confidence interval [CI], 1.59-29.13] and 10.92 [1.15-104.06], respectively). Surgery was not associated with better survival rates at 6 months. Patients who received L-amB alone had a better 6-month survival rate than those who received an echinocandin alone (aOR, 13.52; 95% CI, 1.03-838.10). "Maintenance" fluconazole therapy, prescribed in 21 patients for a median duration of 13 months (range, 2-84 months), led to minor adverse effects.Conclusion: L-amB induction treatment improves survival in patients with PVE-C. Medical treatment followed by long-term maintenance fluconazole may be the best treatment option for frail patients