Effects of urea addition on the fermentation of sorghum (Sorghum bicolor) silage

This study was conducted to evaluate the effects of urea addition on fermentation characteristics, losses and chemical composition of silage of sorghum (Sorghum bicolor) ‘BRS Ponta Negra’. The sorghum plant was chopped and treated with different levels of urea (0.1756, 0.3512, 0.7024 and 1.4048 g per 10 kg fresh forage for the respective proportions of 0.5%, 1.0%, 2.0% and 4.0% of forage (dry matter [DM] basis), and packed into quintuplicate experimen- tal silos to determine its effects on fermentation, losses and chemical composition of sorghum silages. Addition of urea increased lactic acid bacteria up to the level of 60 g kg^?1 (DM basis). Compared with control silage, the addition of urea (p < 0.05) reduced DM losses. Urea-treated silages linearly increased (p < 0.05) the ammoniacal nitrogen and crude protein contents, and linearly reduced (p < 0.05) the ethanol content. The pH in urea-treated silages indicated better preservation of substrates obtained from fermentation. The intermediate level of 2.0% urea additive can be used to improve fermentation, reducing losses in sorghum silage without compromising lactic acid production. However, the addition of 0.5% and 1.0% urea to sorghum silage is sufficient to improve aerobic stability.     

Incorporating soil ecosystem services into urban planning: status,challenges and opportunities

Context

Traditionally soils have not received much attention in urban planning. For this, tools are needed that can both be understood both by soil scientists and urban planners.

Purpose

The purpose of this paper is to enhance the role of soil knowledge in urban planning practice, through the following objectives: (1) identifying the role soil plays in recent urban plans; (2) analysing the ecosystem services and indicators used in soil science in an urban context; and (3) inferring the main challenges and opportunities to integrate soil into urban planning.

Methods

Seven urban plans and reports of world cities that include sustainability goals were analysed using text-mining and qualitative analysis, with a critical view on the inclusion of soil-related concepts. Secondly, the contribution of soil science to urban planning was assessed with an overview of case studies in the past decade that focus on soil-related ecosystem services in urban context.

Results

The results show an overall weak attention to soil and soil-related ecosystem services in the implementation and monitoring phases of urban plans. The majority of soil science case studies uses a haphazard approach to measure ecosystem service indicators which may not capture the ecosystem services appropriately and hence lack relevance for urban planning.

Conclusions

Even though the most urban plans assessed recognize soil as a key resource, most of them fail to integrate indicators to measure or monitor soil-related functions. There is a need to develop soil-related ecosystem services that can be easily integrated and understood by other fields.

     

Carbohydrate profiling and protein identification of tegumental and excreted/secreted glycoproteins of adult Schistosoma bovis worms

Schistosoma bovis is a parasite of wild and domestic ruminants that is broadly distributed throughout many tropical and temperate regions of the old world. S. bovis causes severe health problems and significant economic losses in livestock, but in contrast to human schistosomes, S. bovis has been little investigated at a molecular level. Since schistosome glycans and glycoproteins can play important roles in the host-parasite interplay, the aims of the present work were: (i) to characterize the glycans expressed by adult S. bovis worms on their excreted/secreted (ES) and tegumental (TG) glycoproteins and (ii) to identify their carrier protein backbones by mass spectrometry. Using a panel of lectins and monoclonal and polyclonal anti-glycan antibodies, we observed: (i) the absence of sialic acid in S. bovis; (ii) the presence of complex-type N-glycans and LDN antennae on ES glycoproteins; (iii) the presence of glycans containing the Fucalpha1-2Galbeta motif in many TG glycoproteins, and (iv) the presence of glycans containing the Fucalpha1-3GlcNAc motif on many ES and TG glycoproteins but, simultaneously, the absence of the F-LDN(-F) glycans from both the ES and TG glycoproteins. Interestingly, we also found the Lewis(X) and Lewis(Y) antigens co-expressed on several TG isoforms of ATP:guanidino kinase and glyceraldehyde-3-phosphate dehydrogenase. Finally, by ELISA we observed the presence of antibodies against Lewis(X), Lewis(Y) and F-LDN(-F) in the sera of sheep experimentally infected with S. bovis.     

Infectivity of seropositive dogs, showing different clinical forms of leishmaniasis, to Lutzomyia longipalpis phlebotomine sand flies

Visceral leishmaniasis (VL) is a growing zoonosis with an increasing number of new cases and a rapid geographical spreading of the disease. In the present study, a canine survey was carried out in the city of Montes Claros (320,000 inhabitants), an endemic area of American visceral leishmaniasis in the state of Minas Gerais, Brazil. A total number of 4795 dogs were examined by serology, which showed a rate of seropositivity of 5%. Isoenzymatic analysis confirmed Leishmania infantum chagasi as the local aetiological agent of CVL. Canine tissues were assayed for the presence of Leishmania parasite DNA using different techniques. The infectivity of asymptomatic, oligosymptomatic and symptomatic seropositive dogs was tested by xenodiagnosis using laboratory reared Lutzomyia longipalpis. Rates of infection of 5.4%, 5.1% and 28.4% were found for the phlebotomine sand flies that fed in asymptomatic, oligosymptomatic and symptomatic dogs, respectively. Our results indicate that, under experimental conditions, symptomatic dogs are about four times more infective to VL vectors than oligosymptomatic or asymptomatic animals. The lower infectivity rates of dogs displaying any of the last two clinical forms of leishmaniasis, however, must be taken into account in the epidemiology of CVL.     

Identification of point mutations in a putative carboxylesterase and their association with acaricide resistance in Rhipicephalus (Boophilus) microplus (Acari: Ixodidae)

Chemical control based on the use of pyrethroid and organophosphate compounds has selected resistant genotypes in populations of Rhipicephalus (Boophilus) microplus. Point mutations in esterase-encoding genes represent one of the main resistance mechanisms in this species. In this study, the PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) technique was used to investigate the presence of mutations in a fragment of a putative carboxylesterase in a population of ticks with a history of resistance. The digestion of a fragment of 372 pb with EcoRI revealed three genotypes: W, H and M, observed in different frequencies. The homozygous wild-type genotype (W) was detected only in sensitive strains, with high frequency. The heterozygous genotype (H) was observed in all the strains, albeit with higher frequency in the strains with a moderate resistance, while the homozygous mutant genotype (M) was found only in the moderate resistant strain and resistant strains, with higher frequency in the resistant strains. A comparison of the sequences indicated the presence of other mutations, besides EcoRI polymorphism in the moderate resistant and resistant strains. Also found was the presence of stop codons generating truncated proteins in the sensitive and moderate resistant strains. A domain analysis revealed the presence of additional domains in the resistant strain. These findings suggest that different point mutations, as well as the influence of post-translational modification mechanisms, are altering the activity of the translated proteins and may be associated with resistance.     

Subarachnoid butorphanol augments lidocaine sensory anaesthesia in calves

To determine the efficacy and safety of subarachnoid butorphanol combined with lidocaine, six calves were studied. Each calf underwent two treatments, at least one week apart, via subarachnoid injection: (1) butorphanol (0.03 mg/kg) plus 2% lidocaine (4 mg/kg) and (2) 2% lidocaine (4 mg/kg) alone. Subarachnoid injections were performed at the lumbosacral space. Analgesia, motor block, sedation, heart rate, arterial blood pressure, respiratory rate, arterial oxygen saturation as measured by pulse oximetry, and rectal temperature were compared before and after subarachnoid administration of drugs. Subarachnoid administration of the butorphanol-lidocaine combination induced bilateral prolonged analgesia extending from the coccygeal to the T11-T13 dermatomes in the calves, with minimal sedation and severe ataxia. Cardiovascular effects were significant in both treatments: heart rate was increased, and there was a minimal decrease in arterial pressure. It was concluded that adding a small dose of butorphanol to subarachnoid lidocaine in calves is effective and safe.     

Does Rhipicephalus microplus tick infestation increase the risk for myiasis caused by Cochliomyia hominivorax in cattle?

The larval phase of Cochliomyia hominivorax (screwworm) is an obligate parasite of vertebrate animals, particularly mammals, and widespread in South America, where it remains one of the most important parasitic diseases of domestic animals. The skin of cattle highly infested by ticks, with cutaneous lesions, exudation of tissue fluid and blood scent seems to produce the ideal environment for fly attraction. However, an association between these parasites was never investigated. The aim of this work was to verify if there is an association between Rhipicephalus microplus tick load and the occurrence of C. hominivorax myiasis in cattle, and to quantify the risk. Sixty bovine (Bos taurus taurus, Angus breed) under field conditions were observed for 24 weeks, during which weekly tick counts and examination for the presence of myiasis were performed. There was a significant association between a high tick burden (24-week mean above 50 ticks per animal) and myiasis occurrence (P = 0.0102). The calculated relative risk (RR) for C. hominivorax myiasis occurrence in cattle with high tick burden was 3.85 (CI95% = 1.23–12.13); indicating that cattle highly parasitized by R. microplus have about four times more risk of myiasis than those with a low parasite load. As far as we aware, this is the first statistically based evidence of the relationship between R. microplus parasitic load and occurrence of myiasis by C. hominivorax. This result could be useful for the design of integrated control strategies for these parasites and to provide more information for the understanding of cattle tick parasitism in cattle production.