Effects of dietary inclusion of sunflower soap stocks on colour, oxidation and microbiological growth of meat from light fattening lambs

[EN] Thirty-two lambs were finished on a total mixed ration (TMR) pelleted alone (00SS) or including sunflower soap stock (SS): 15SS (15 g SS per kg TMR), 30SS (30 g SS per kg TMR) and 60SS (60 g SS per kg TMR). Lambs (8 per group) were slaughtered at 27 kg live weight. Colour evolution, lipid oxidation, microbial growth and detection of diarrhoeagenic Escherichia coli were studied in meat samples. SS in the diet reduced meat lipid oxidation (P 0.05) on the cholesterol oxidation products. Meat from 60SS and control animals (00SS) revealed greater discoloration (P < 0.05) than 15SS. SS supplementation did not affect the microbiological populations, whereas high doses of SS seemed to increase the proliferation of diarrhoeagenic E. coli on day 14 (P < 0.10). These results suggest that the rate of SS inclusion in the diet of fattening lambs should not be above 15 g SS per kg TMR.S

The relative effects of upwelling and river flow on the phytoplankton diversity patterns in the ria of A Coruña (NW Spain)

Phytoplankton species assemblages in estuaries are connected to those in rivers and marine environments by local hydrodynamics leading to a continuous flow of taxa. This study revealed differential effects of upwelling and river flow on phytoplankton communities observed in 2011 along a salinity gradient from a river reservoir connected to the sea through a ria-marine bay system in A Coruña (NW Spain, 43° 16-21’ N, 8° 16-22’ W). With 130 phytoplankton taxa identified, the assemblages were dominated in general by diatoms, particularly abundant in the bay and in the estuary, but also by chlorophycea and cyanobacteria in the reservoir. Considering the entire seasonal cycle, the local assemblages were mainly characterized by changes in cryptophytes and diatoms, small dinoflagellates and some freshwater chlorophycea. Salinity, nitrate, and organic matter variables, were the main environmental factors related to the changes in the phytoplankton communities through the system, while phosphate and nitrite were also important for local communities in the estuary and the bay, respectively. The corresponding local phytoplankton assemblages showed moderate levels of connectivity. The estuarine community shared a variable number of taxa with the adjacent zones, depending on the relative strength of upwelling (major influence from the bay) and river flow (major influence of the reservoir) but had on average 35% of unique taxa. Consequently, local and zonal diversity patterns varied seasonally and were not simply related to the salinity gradient driven by the river flow.ANILE (CTM2009-08396 and CTM2010-08804-E), FIOME (CTM2011-28792-C02-01-MAR), and MEFIO (CTM2011-28792-C02-02-MAR) of the Plan Nacional de I+D+i (Spain), and RADIALES of the Instituto Español de Oceanografía (IEO, Spain).Versión del editor2,01

Evaluating the performance of the particle finite element method in parallel architectures

This paper presents a high performance implementation for the particle-mesh based method called particle finite element method two (PFEM-2). It consists of a material derivative based formulation of the equations with a hybrid spatial discretization which uses an Eulerian mesh and Lagrangian particles. The main aim of PFEM-2 is to solve transport equations as fast as possible keeping some level of accuracy. The method was found to be competitive with classical Eulerian alternatives for these targets, even in their range of optimal application. To evaluate the goodness of the method with large simulations, it is imperative to use of parallel environments. Parallel strategies for Finite Element Method have been widely studied and many libraries can be used to solve Eulerian stages of PFEM-2. However, Lagrangian stages, such as streamline integration, must be developed considering the parallel strategy selected. The main drawback of PFEM-2 is the large amount of memory needed, which limits its application to large problems with only one computer. Therefore, a distributed-memory implementation is urgently needed. Unlike a shared-memory approach, using domain decomposition the memory is automatically isolated, thus avoiding race conditions; however new issues appear due to data distribution over the processes. Thus, a domain decomposition strategy for both particle and mesh is adopted, which minimizes the communication between processes. Finally, performance analysis running over multicore and multinode architectures are presented. The Courant&ndash;Friedrichs&ndash;Lewy number used influences the efficiency of the parallelization and, in some cases, a weighted partitioning can be used to improve the speed-up. However the total cputime for cases presented is lower than that obtained when using classical Eulerian strategies

Effects of replacing barley straw and corn silage by olive cake in the diet on microbial populations in RUSITEC fermenters

By-products are an important waste in agro-food industry in many countries, and they can represent an environmental problem, as they are difficult to eliminate. Their use in ruminant feeding could alleviate this problem and contribute to a more sustainable livestock production. Olive cake is a by-product of olive oil extraction that contains bioactive compounds with antimicrobial and antioxidant activities that could also affect the ruminal microbiota, but this aspect has not yet been investigated. Four Rusitec fermenters were used in a cross-over design in two 14-day incubation runs to study the effects of replacing part of the forage by olive cake in a dairy sheep diet on microbial populations. Three rumen-cannulated Merino sheep were used as ruminal content donors for inoculation of the system. Experimental diets were a conventional diet for dairy sheep (50:50 forage:concentrate) with corn silage and barley straw as forage, and a diet in which corn silage and barley straw were partially replaced by olive cake (16.7%). Samples of liquid and solid digesta were collected from the fermenters at the end of each incubation run. DNA was extracted and the abundance of bacteria and protozoa, as well as the relative abundance of fungi and archaea, were assessed by qPCR. Bacterial diversity was analysed using Automated Ribosomal Intergenic Spacer Analysis (ARISA). Data were processed using R with the vegan package and the PROC MIXED from SAS. The number of peaks detected in the ARISA electropherograms and the Shannon’s index were not affected (P>0.05) by the inclusion of olive cake in the diet, but they were higher (P=0.006 and P=0.005, respectively) in liquid than in solid digesta. Principal coordinates analysis based on Bray-Curtis distance showed that samples were not clearly grouped by diet, due to the variability of samples from the same diet and the strong effect of the digesta phase. Bacterial and protozoal abundance in the liquid digesta and the relative abundance of fungi and archaea in both digesta phases were not affected (P>0.05) by the inclusion of olive cake in the diet. In the solid digesta, diet affected (P=0.013) the bacterial abundance and tended to affect (P=0.06) the protozoal abundance, both being higher for the diet containing olive cake than for the conventional diet. In conclusion, the addition of olive cake in substitution of corn silage and barley straw in the diet promoted greater bacterial and protozoal growth in the solid digesta of Rusitec fermenters

Effects of replacing barley straw and corn silage by olive cake in the diet on microbial populations in RUSITEC fermenters

By-products are an important waste in agro-food industry in many countries, and they can represent an environmental problem, as they are difficult to eliminate. Their use in ruminant feeding could alleviate this problem and contribute to a more sustainable livestock production. Olive cake is a by-product of olive oil extraction that contains bioactive compounds with antimicrobial and antioxidant activities that could also affect the ruminal microbiota, but this aspect has not yet been investigated. Four Rusitec fermenters were used in a cross-over design in two 14-day incubation runs to study the effects of replacing part of the forage by olive cake in a dairy sheep diet on microbial populations. Three rumen-cannulated Merino sheep were used as ruminal content donors for inoculation of the system. Experimental diets were a conventional diet for dairy sheep (50:50 forage:concentrate) with corn silage and barley straw as forage, and a diet in which corn silage and barley straw were partially replaced by olive cake (16.7%). Samples of liquid and solid digesta were collected from the fermenters at the end of each incubation run. DNA was extracted and the abundance of bacteria and protozoa, as well as the relative abundance of fungi and archaea, were assessed by qPCR. Bacterial diversity was analysed using Automated Ribosomal Intergenic Spacer Analysis (ARISA). Data were processed using R with the vegan package and the PROC MIXED from SAS. The number of peaks detected in the ARISA electropherograms and the Shannon’s index were not affected (P>0.05) by the inclusion of olive cake in the diet, but they were higher (P=0.006 and P=0.005, respectively) in liquid than in solid digesta. Principal coordinates analysis based on Bray-Curtis distance showed that samples were not clearly grouped by diet, due to the variability of samples from the same diet and the strong effect of the digesta phase. Bacterial and protozoal abundance in the liquid digesta and the relative abundance of fungi and archaea in both digesta phases were not affected (P>0.05) by the inclusion of olive cake in the diet. In the solid digesta, diet affected (P=0.013) the bacterial abundance and tended to affect (P=0.06) the protozoal abundance, both being higher for the diet containing olive cake than for the conventional diet. In conclusion, the addition of olive cake in substitution of corn silage and barley straw in the diet promoted greater bacterial and protozoal growth in the solid digesta of Rusitec fermenters