Development of a CE method to analyze organic acids in dairy products: application to study the metabolism of heat-shocked spores

Organic acids are relevant in dairy products for nutritional reasons and because they contribute to the flavor and aroma. They are the major products of carbohydrate catabolism of lactic acid bacteria and nonstarter bacteria associated with milk. In several research and quality programs, it is very important to develop a rapid and sensitive method for their quantitative determination in dairy products to monitor bacterial growth and activity. A capillary electrophoresis method for the simultaneous determination of oxalic, citric, formic, succinic, orotic, uric, pyruvic, acetic, propionic, lactic, and butyric acid in less than 18 min has been developed. Various parameters affecting analysis, including capillary length, type, composition, and pH of the electrolyte have been optimized. Some alternatives are given to improve the separation of particular organic acids of special interest. Its application to analyze the quality of some dairy products has been investigated. In addition, the suitability of the technique to determine profiles of organic acids generated during the metabolism of heat-shocked spores has been demonstrated.     

Post-logging recovery time is longer than expected in an East African tropical forest

Uncertainty in recovery times of tropical forests can lead to mismanagement, such as in setting inappropriate harvesting rates or failing to achieving conservation targets. We use long-term plot data (17 y) to estimate recovery times of separate forest compartments, which experienced different levels of timber extraction within Kibale National Park, Uganda. We estimate that structural recovery (basal area) of heavily logged and moderately logged compartments will take respectively 112 and 95 y, when compared to adjacent mature forest. Our data suggests that recovery in terms of species composition will take significantly longer. Our estimates of structural recovery are derived from rates of change of diameter at breast height and basal area measurements which have been used traditionally as indicators of forest growth and productivity. Our results suggest that the severity of the logging has an impact on the rate of recovery, with current recovery rates estimated at 0.32 m² ha⁻¹ y⁻¹ in a moderately logged compartment and 0.25 m² ha⁻¹ y⁻¹ in heavily logged areas, highlighting the possible benefits of reduced impact harvesting in increasing long-term yields. We investigate how some representatives of the wildlife community were affected by differential recovery times and find that recovery times of frugivorous primate's forest habitats were 2.5 times slower when compared with folivorous primates.     

Screening genetic diseases prevalence in Braunvieh cattle

Tropical Animal Health and Production - Heritable abnormalities can cause a reduction in productive performance, structural defects, or death of the animal. There are reports of hereditary...     

Simulation modeling of influenza transmission through backyard pig trade networks in a wildlife/livestock interface area

Tropical Animal Health and Production - Influenza constitutes a challenge to animal and human health. It is a highly contagious disease with wildlife reservoirs and considered as endemic among...     

Organic or conventional dairy farming in northern Spain: Impacts on cow reproductive performance

Organic farming has traditionally given preference to indigenous breeds that are well adapted to local conditions; however, current trends towards increased yields may produce less robust animals with potentially low fertility. The Holstein‐Friesian breed dominates dairy sector, although there is a general concern that these cows may not be well adapted to organic systems. This study aims to evaluate the reproductive performance of organic dairy herds in northern Spain, by comparing organically reared Holstein‐Friesian with their counterparts reared on conventional farms and also with other organically reared breeds and crosses. Reproductive parameters were obtained for individual cows on organic, conventional pasture‐based and conventional zero‐grazing farms. The reproductive performance of Holstein‐Friesian cows was slightly better in organic systems than in pasture‐based conventional systems, but not than in zero‐grazing conventional systems. The comparison of reproductive performance of Holstein‐Friesian from organic and conventional systems and with other organically reared breeds and crosses enabled us to demonstrate that it is not the organic system that constrains the reproductive performance of Holstein‐Friesian, but that the manifestation of oestrus is less marked than in other breeds. Breeding selection considering reproductive traits and appropriate management of oestrous detection would improve the reproductive performance of Holstein‐Friesian cows.     

An automated method for the measurement of methaemoglobin in avian blood

An automated method has been developed for the measurement of methaemoglobin (metHb) in blood using a biochemistry analyser. The method was validated using blood collected from red-legged partridges exposed in vitro to increasing concentrations of nitrite in order to obtain different percentages of metHb. Results obtained using the original manual method and those using the new automated technique were compared and no significant differences were found. Intra-day and inter-day variabilities (8.8% and 2.6%, respectively) were acceptable for samples containing high levels (63-81%) of metHb. Methaemoglobin measured in blood samples stored in liquid nitrogen was stable for 10 days, but increased significantly by day 20 in nitrite-treated samples.     

Euparyphium albuferensis and Echinostoma friedi (Trematoda: Echinostomatidae): experimental cercarial transmission success in sympatric snail communities

Euparyphium albuferensis and Echinostoma friedi cercarial infectivity to four species of sympatric snails was examined under single- or multiple-choice laboratory conditions to show the level of parasite-snail host compatibility. Radix peregra, Lymnaeafuscus, Physella acuta and Gyraulus chinensis act as second intermediate hosts of both parasite species although different cercarial transmission success (CTS) was observed. In single-host experiments, R. peregra and P. acuta showed a high degree of compatibility with E. albuferensis, while only P. acuta in the case of E. friedi. In two-choice snail communities, a snail with high CTS increased the values of another with low compatibility, in both parasite species. In multiple-choice snail communities, high CTS of some hosts decreased, while low CTS of other hosts increased. The degree of parasite-host compatibility of each snail species could be determined by the presence of other snails in the community.     

Initial growth and survival of Eucalyptus spp. and Mimosa caesalpiniifolia Benth. in silvopastoral systems and their impact on herbage accumulation of Urochloa decumbens Stapf R. D. Webster

Agroforestry Systems - Silvopastoral systems (SPS) combine tree, herbaceous, and animal components, and may contribute to improve productivity and diversification of activities over time. This...