SUMMARYIn Uruguay, many beekeepers transport their colonies to Eucalyptus grandis plantations at the end of the summer and autumn, obtaining important honey harvests. However, at the end of the flowering period the colonies become extremely weakened undergoing high levels of mortality. Nutritional and health problems could explain the weakening of colonies. In order to find out the causes for this weakening, colonies of the same size were taken to an E. grandis plantation, split up in three groups differentiated by the availability of pollen. Throughout the flowering period we registered: the botanical origins and crude protein content of the incoming pollen, the body protein of the bees, the infection by Nosema ceranae and the infestation of Varroa destructor, the brood area and the production of honey. The most important findings were: i) the sustained decline in botanical diversity of pollen as the flowering period of E. grandis advanced until only pollen from this species remained; ii) pollen from E. grandis presented crude protein values close to 30%, but these gradually diminished reaching values lower than 20% towards the end of the flowering period; iii) those colonies which initially counted on pollen reserves presented bees with higher body protein a few days after settling in the plantation and lower levels of infection with N. ceranae during most of the flowering period; iv) pollen availability did not affect levels of infection by V. destructor, size of the brood area or honey production. Bee's nutritional deficit during E. grandis flowering could generate adequate conditions for the multiplication of N. ceranae. At the end of the Eucalyptus' flowering period colonies presented on average more than 90% of foraging workers infected with N. ceranae and 12% infection of adult bees with V. destructor. Incidence of both pathogens in weakened bees could explain colony losses. RESUMENEn Uruguay muchos apicultores trasladan sus colonias a las forestaciones de Eucalyptus grandis al final del verano y en otoño obteniendo importantes cosechas de miel. Sin embargo, cuando finaliza la floración las colonias se encuentran muy debilitadas, sobreviniendo una elevada mortalidad. Problemas nutricionales y sanitarios podrían explicar el debilitamiento de las colonias. Para averiguar las causas del debilitamiento se llevaron colonias de igual tamaño a una forestación de E. grandis, separadas en tres grupos diferenciados por la disponibilidad de polen. A lo largo del periodo de floración se registró: el origen botánico y el contenido de proteína cruda del polen que ingresaba en las colmenas, la proteína corporal de las abejas, la infección por Nosema ceranae y la infestación por Varroa destructor, el área de cría y la producción de miel. Los resultados más importantes hallados fueron: i) la sostenida disminución de la diversidad botánica del polen a meArchivos de zootecnia vol. 60, núm. 232, p. 1304. INVERNIZZI, SANTOS, GARCÍA, DANERS, DI LANDRO, SAADOUN AND CABRERA dida que transcurría el periodo de floración de E. ...

The aim of this study was to assess the effect of several operational variables on both biological and separation process performance in a submerged anaerobic membrane bioreactor pilot plant that treats urban wastewater. The pilot plant is equipped with two industrial hollow-fiber ultrafiltration membrane modules 2 KeywordsBiogas production; hollow-fiber membrane; industrial membranes; submerged anaerobic membrane bioreactor; urban wastewater

In the Velasco zone, Holguín province, Cuba, losses in yield due to the bean rust were valued on the varieties ICA- Pijao, Velasco Largo and Bonita 11 in four sowing times between 1987 and 1989. A randomized block design with three replicates was used. The considered treatments were the aforesaid three varieties of common bean, sprayed with fungicides and unprotected. The used chemical was oxycarboxin, sprayed five times at 0.75 kg a.i. 1 ha with a 10 days frecuency, beginning 15 days after sowing. It was concluded that bean rust might cause shortages in yield reaching 28-54%, 8-33% and 13-29% on the varieties ICA- Pijao, Velasco Largo and Bonita 11 respectively as well as a decrease on the average number of pods per plant and also the weight of the seeds.

Using whole oats grain as a source of fiber in calves' rations. Agrociencia Uruguay [Internet]. 2021 [cited dd mmm yyyy];25(1):372. Available from: http://agrocienciauruguay. uy/ojs/index.php/agrociencia/article/view/372 Using whole oats grain as a source of fiber in calves' rations Utilización del grano entero de avena como fuente de fibra en raciones para terneros Utilização de grão inteiro de aveia como fonte de fibra na ração de bezerros

The effect of different feed substrates incubated in filter bags [no bag (NB); Ankom® F57, 25 μm pore size (25AN); polyester, 45 μm pore size (45PB); polyester, 67 μm pore size (67PB) ] or dispersed in the medium on gas production, digestion and rumen fermentation was evaluated using an in vitro gas production system. Filter bags reduced (P < 0.01) gas production but increased (P < 0.01) the in vitro dry matter digestibility (45PB and 67PB). Additionally, the use of filter bags with smaller pore size, reduced total volatile fatty acid (P < 0.01), but had minimal effects on acetate, propionate, and butyrate concentration. Our research suggested that using filter bags with a pore size of 67 µ would reduce some negative effects of incubating feed substrate dispersed in the medium or in filter bags with smaller pore size. However, the use of bags with a larger pore size might allow the wash out of small feed particles with consequent overestimation of digestibility.