Produção de madeira e retorno financeiro em dois sistemas silvopastoris

Silvopastoral systems combine forestry and livestock activities, establishing productive and economic interactions that must be known in order to project their viability in the medium to long term. Important aspects of these systems are spacing arrangement, wood production and economic return. The present study was carried out on a farm with commercial forestry and aimed at evaluating wood production and its financial return in two silvopastoral systems of Eucalyptus globulus: Conventional Forestry System (CFS) in a plantation arrangement of 3.5×2.7 m, and Silvopastoral System (SSRA) (2×2)+8 m of alley. Each system was evaluated in three strata, at age 68 months. No differences (p> 0.05) were found for Survival (S), Diameter at Breast Height (DBH), Height (H), and Dominant Height (DH) between CFS and SSRA values. However, both systems differed (p 0.05) entre CFS y SSRA para sobrevivencia (S), diámetro a la altura de pecho (DBH), altura (H) y altura dominante (DH). Sin embargo, ambos sistemas se diferenciaron (p 0,05) para sobrevivência (S), diâmetro á altura do peito (DBH), altura (H) e altura dominante (DH) entre os valores de CFS e SSRA. No entanto, ambos os sistemas diferiram (p <0,05) nos valores de produção de madeira (m³/ha) aos 68 meses: CFS produziu 83.7 m³/ha, enquanto SSRA produziu de 60 m3/ha. As rotações ótimas estimadas foram de 12 e 13 anos para CFS e SSRA, respectivamente. A Renda Anual Equivalente (EAI) foi de 140 e 141 US$/ha/ano para CFS e SSRA respectivamente. No entanto, SSRA exige um menor investimento no plantio e proporciona maior liquidez ao longo da rotação. Os sistemas florestais podem ser desenhados de forma a permitir uma maior integração espacial da pecuaria, transformando-se em sistemas mais complementares

Zimevit: un biofungicida que combina la acción de una bacteria y una levadura para el control del moho gris de la vid ocasionado por Botrytis cinerea.

Botrytis cinerea, provoca pérdidas importantes en la producción de vid. Zimevit, un biofungicida desarrollado en Uruguay que combina la acción de una bacteria (Bacillus subtilis, UYBC38) y una levadura (Metschnikowia pulcherrima, M26) fue evaluado a campo en las variedades Cabernet Franc y Gewurztraminer. Los tratamientos fueron: Zimevit; iprodione como tratamiento convencional y agua como testigo. En los tres ensayos efectuados la aplicación de Zimevit resultó en una menor incidencia y severidad del moho gris en los racimos al momento de la cosecha sin diferenciarse del fungicida iprodione. El hecho de que Zimevit haya logrado reducir tanto la incidencia como la severidad de la enfermedad estaria demostrando la existencia de un doble efecto inhibitorio, tanto sobre la germinación de esporas como sobre el desarrollo posterior de la enfermedad. Si bien se recomienda realizar nuevas evaluaciones para conocer su comportamiento en años con clima favorable al desarrollo de la enfermedad, puede afirmarse que Zimevit aparece como una herramienta potencial a ser usada en sistemas de manejo integrado del moho gris de la vid en Uruguay

Efecto de la suplementación con granos secos de destilería (DDGS) sobre los parámetros de la fermentación ruminal in situ en vacunos pastoreando sorgo forrajero (Sorghum spp)

Aim. To evaluate the effect of supplementation with distillers dried grains (DDGS) on in situ ruminal fermentation parameters by cattle grazing on forage sorghum. Materials and methods: Four Hereford heifers (793 ± 73 kg live weight) using a ruminal cannula, grazing on forage sorghum, with day-in enclosure and artificial shade, were part of a randomized crossover design study with two treatments: without supplementation (WOS) and with supplementation (WS), fed on DDGS. The experimental design comprised two 14-day periods (10 days for diet transition, and 4 days for measurements). Results: Supplementation did not affect DM consumption (P &gt; 0.05), though it increased total consumption (P &lt; 0.05). The WS treatment caused lower ruminal pH (6.17 vs. 6.55; (P &lt; 0.05), and greater N_NH4 concentration (P &lt; 0.05). The effective degradability of DM was 51.25%, the same as the other treatment (P &gt; 0.05), whereas the effective NDF was lower in the WS treatment (P &lt; 0.05). DM digestibility in WS was lower (65.75 vs. 60.75%), whereas NDF digestibility was 68.50 vs. 62.50%. Conclusion: DDGS supplementation decreased ruminal pH and raised N_NH4 concentrations, reducing the fiber’s effective degradability of DM and NDF. Keywords: DDGS, heifers, supplementation (Source: AGROVOC)Objetivo. Evaluar el efecto de la suplementación con granos secos de destilería más solubles (DDGS) sobre los parámetros de la fermentación ruminal in situ en vacunos pastoreando sorgo forrajero. Materiales y métodos: Cuatro novillos Hereford (793 ± 73 kg peso vivo) provistos de cánula ruminal pastoreando sorgo forrajero con encierro diurno y sombra artificial fueron asignados al azar en diseño crossover a dos tratamientos: sin suplemento (SS) y suplementados (CS), con DDGS. El diseño experimental comprendió dos períodos de 14 días (10 transición entre dietas; 4 de mediciones). Resultados: La suplementación no afectó el consumo de MS de forraje (P &gt; 0,05), pero sí aumentó el consumo total (P &lt; 0,05). El tratamiento CS presentó menor pH ruminal (6,17 vs. 6,55; (P &lt; 0,05) y mayor concentración N_NH4 (P &lt; 0,05). La degradabilidad efectiva de la MS fue 51,25% sin diferencias entre tratamientos (P &gt; 0,05), mientras que la degradabilidad efectiva de la FDN fue menor CS (P &lt; 0,05). La digestibilidad de la MS (65,75 vs 60,75%) y de la FDN (68,50 vs 62,50%) fue menor CS. Conclusión: La suplementación con DDGS disminuyó el pH ruminal y aumentó las concentraciones de N_NH4, disminuyendo la degradabilidad efectiva de la fibra y la digestibilidad de la MS y FDN. Palabras clave: DDGS, novillos, suplementación (Fuente: AGROVOC

Efecto de la temperatura de refrigeración sobre la calidad de la carne de novillos

At the "Dr. Mario Cassinoni" Experimental Station of the Facultad de Agronomí­a in Paysandíº, Uruguay the effect of refrigeration temperature was studied, 4.5 ºC +- 0.2 for control, and 11.0 ºC +- 0.5 (average and standard deviation, respectively) for treatment for the period of twelve h, on Holstein steers' hygienic and instrumental meat quality. Carcass weight losses due to airing, pH, a* and b* color measurements, losses due to cooking and sarcomere length were not affected by refrigeration treatments (P>0.05). Meanwhile carcasses that were kept in airing chambers at 11 ºC for 12 h showed lower L* values (luminosity) and a significant increase in microorganism count (total anaerobic) in a sample carried out 24 h post mortem. Anyway values can be considered as acceptable. Texture results confirm that this variable improves with ageing, independently of temperature (3.2, 2.9, 2.6 and 2.5 kg for 1, 7, 14 and 21 ageing, respectively), especially during the first two weeks.En la Estación Experimental "Dr. Mario A. Cassinoni" de la Facultad de Agronomí­a (Paysandíº, Uruguay), se evaluó el efecto de la temperatura de refrigeración, grupo testigo (4.5 +- 0.2 °C) y grupo tratado (11.0 +- 0.5 °C) durante 12 h a temperatura de oreo: (promedio y desviación estándar, respectivamente), sobre la calidad higiénica e instrumental de la carne de novillos Holstein. Las pérdidas por oreo de la canal, el pH, las mediciones a* y b* del color, las pérdidas por cocción y la longitud de sarcómero no resultaron afectadas por los tratamientos de refrigeración (P>0.05). Las canales que permanecieron en cámara de oreo a 11 ºC por 12 h, mostraron valores de luminosidad (L*) más bajos y un incremento significativo en el níºmero de microorganismos (aerobios totales) en el muestreo realizado a las 24 h postmortem. De todas formas, los valores se consideran aceptables. Los resultados en textura confirman la mejora en dicha variable conforme transcurrió la maduración, independientemente de la temperatura de refrigeración (3.2, 2.9, 2.6 y 2.5 kg, para 1, 7, 14 y 21 dí­as de maduración, respectivamente), principalmente durante las dos primeras semanas

Revista de Ciencias Sociales (Vol. 22 no. 25 jul 2009)

Juventud como objeto, jóvenes como sujetos. Presentación/ Verónica Filardo Notas sobre a invençâo social de um singular sujeito de dereitos. Juventude, juventudes/ Regina Novaes La construcción social de las juventudes/ Carlos Basilio Muñoz De los herederos a los desheredados. Juventud, capital escolar y trayectorias de vida/ Oscar Dávila León, Felipe Ghiardo Soto Las marcas de clase de la inseguridad ciudadana. Juventud y pobreza/ Gabriel Chouhy, Sebastián Aguiar, Laura Noboa Adiós juventud: tendencias en las transiciones a la vida adulta en Uruguay/ Santiago Cardozo, Alejandra Iervolino Reflexiones sobre equidad entre clases de edad/ Verónica Filardo De jóvenes ni, ni que habitan Casavalle. Representaciones sociales desde espacios de exclusión/ Fabiana Espíndola Fragmentación socioeconómica y segregación urbana en Montevideo/ Danilo Veiga, Ana Laura Rivoir Diagnóstico y repertorio de políticas para el rediseño institucional de la enseñanza media en Uruguay/ Nicolás Bentancur, Tabaré Fernández Reseñas de libros El Uruguay del siglo XX. La sociedad/ Sylvia González La movilidad social en el Uruguay contemporáneo/ Enrique Mazzei La implementación de normas de calidad en la industria uruguaya. Entre la innovación y el ritualismo/ Graciela Lescano Las bases invisibles del bienestar social. El trabajo no remunerado en Uruguay/ Alejandra Iervolino Las batallas por la subjetividad: luchas sociales y construcción de derechos en Uruguay/ Pedro Robert

Using whole oats grain as a source of fiber in calves’ rations

Two experiments were carried out aiming to study the value of whole oats (WO) as a potential source of physically effective fiber (peNDF) in rations for calves. In experiment 1, 24 Hereford calves (177 ± 18 kg) were randomly assigned to eight groups and these into one of four experimental rations (79% concentrate), varying in the replacement level of grass hay (GH) for WO: 0:21, 7:14, 14:7, 21:0% dry matter (DM) basis WO:GH, respectively. Increasing WO level resulted in a quadratic response for peNDF (P= 0.04) with values above 15% of dm. Intake increased quadratically (P= 0.03) and dm digestibility increased linearly (P= 0.03). As a result, feed conversion efficiency tended to improve (P= 0.08). In Experiment 2, four rumen cannulated steers were assigned in a crossover design to one of two experimental rations (65% concentrate) varying in peNDF fiber source: 35% gh or 35% WO, aiming to study the fermentative pattern. Replacing GH for WO reduced mean daily rumen pH (5.9 vs. 6.3, P < 0.01), varying between 6.1 and 5.8, and always below pH values in gh. No differences were observed for the potentially degradable dm fraction, but fermentation rate was higher for WO (35.0 vs. 9.0 %/ h; P= 0.02), hence increasing effective degradability (58.3 vs. 65.4%; P= 0.048). Results from both experiments suggest it is viable to use WO as a peNDF source for concentrated rations

Udder Hygiene and Mastitis Indicators in Contrasting Environmental Conditions during Half-Time Confinement in Pasture-Based Dairy Systems

This study aimed to compare the association between two types of housing, compost barns (CB) vs. outdoor soil-bedded yard (OD), and udder hygiene and mastitis indicators in Holstein dairy cows calving in autumn (n = 31) and spring (n = 27). After calving, cows were transferred to a pasture-based system with half-time confinement in one of two treatments: CB or OD. The udder hygiene score (UHS) was evaluated monthly and on days after rainfall over the entire lactation period. Individual somatic cell count (SCC) was determined throughout lactation, and the prevalence of intramammary infection (IMI) was estimated. Cows confined in OD presented higher UHS compared to cows in CB (p p < 0.02). However, no differences in IMI and clinical mastitis were found between OD and CB cows in either calving season

Post-weaning feeding levels on feeding behavior, growth and development in Holstein dairy heifers

<div><p>ABSTRACT: To study the effect of post-weaning feeding levels on the growth of dairy heifers, 40 animals with 77.7 ± 8.1 days of age and 77.5 ± 9.2kg of body weight were grouped in 10 pens, and each pen was randomly assigned to one of the following treatments for 120 days: feeding level to achieve a body weight gain of 600 (TMEDIUM) or 800 (THIGH) g/day based on a total mixed ration. After this period all heifers were managed as a single group for 150 days. Nutrient intake, behavior, body weight and other morphological measures were recorded in each animal. As a result of the experimental design THIGH heifers had a higher nutrient intake than TMEDIUM heifers, which was reflected in a higher daily weight gain, withers height, heart girth and hip width. However, treatments had no effect on these traits during the residual period.</p></div

Effects of rice bran and glycerin supplementation on metabolic and productive responses of beef cows

Fifty-seven primiparous Angus, Hereford, and crossbred cows were used to study the effect of strategic supplementation on metabolic, productive, and reproductive responses. The experiment had two periods including four phases: prepartum supplementation (phase I; 52 days), early postpartum (phase II; 43 days), pre-mating supplementation (phase III; 21 days), and the last phase including mating, gestation, and lactation until weaning (phase IV; 103 days). Phases I and II were considered as period 1, and phases III and IV were considered as period 2. During phase I (−52±2 days before calving to birth), half of the cows received a supplement (S-), and the rest only grazed native swards (C-). For phase III (59±2 days postpartum [DPP] until mating), cows from the previous treatments (C- or S-) were sorted in two levels of pre-mating supplementation, supplemented (-S) or not supplemented (-C), resulting in four treatment combinations (CC, CS, SC, and SS). The supplement was 1 kg dry matter/cow per day of whole rice bran and 550 mL/cow per day of crude glycerin. In period 1, cows receiving prepartum supplementation increased concentration of cholesterol, glucose, and albumin and decreased concentration of non-esterified fatty acids, betahydroxybutyrate, and urea. This improvement in energy balance was reflected in a higher body condition score at calving. Alternatively, in period 2, pre-mating supplementation only increased cholesterol concentration. None of the supplementation periods affected the weaning weight of calves. Prepartum, but not pre-mating, supplementation increased total pregnancy rate. A short prepartum supplementation improves pregnancy rate of primiparous cows managed under extensive production systems. However, there is no additional benefit of supplementation during the pre-mating perio

Season of the year, the feeding and productive environment: effect on the content of casein in milk

A study was carried out to determine the casein variation in milk along the year with season and herd feeding strategy as main source of variation. Monthly samples were taken from 30 dairy farms that sent milk to PILI SA (15 farms) and CLALDY SA (15 farms) during April 2012 - March 2013. A mixed model and a recursive partition of variance method were used. The protein content in milk was higher in autumn, and the casein content in milk was higher in autumn and winter probably due to the higher use of energy concentrated supplements with better synchronization with the protein contribution from pastures. It was possible to maintain high levels of casein content and a casein:true protein ratio in milk during spring with almost exclusively pastoral diets. Overall, the proportion of casein in relation to the total protein and the casein in relation to true protein in milk did not reach the values ​​reported in the literature with more concentrated diets