Renal handling of calcium and phosphorus in experimental renal hyperparathyroidism in dogs

Twenty-four hour urinary excretion, fractional excretion and the filtered load of calcium and phosphorus were monitored as hyperparathyroidism evolved in a model of progressive canine renal failure. Thirteen beagles of both sexes aged four and a half months were used. Nine of them were subjected to a renal damaging schedule (neomycine, 60 mg/kg/48 h, IM, 32 weeks) in order to induce chronic renal failure leading to secondary hyperparathyroidism (2HPT group). The remaining four were kept as the control group. The experiment was conducted over 32 weeks. Blood and 24 h urine were collected every four weeks. Calcium, phosphorus and creatinine were analyzed. Plasma parathormone and calcitonin were determined at weeks 0, 12, 24 and 32. The level of renal function in the 2HPT animals was reduced to 25% of that of the controls (endogenous creatinine clearance was 0.45 +/- 0.22 mL/min/kg as opposed to 1.81 +/- 0.54 mL/min/kg). Hyperparathyroidism was confirmed by a progressive increase in the levels of the parathyroid hormone. Calcitonin levels were not modified. A tendency to hypocalcaemia was observed, reaching statistically significant levels from the twenty-eighth week of the study, when hyperphosphataemia also became significant. Daily urinary excretion of calcium and phosphorus remained at values considered normal throughout the experiment with no alteration imputable to the impaired renal function. This is explained by the decrease in the filtered load of these elements (in both cases statistically significant from the 24th week on) being associated with an increase in their fractional excretion. Thus, calcium and phosphorus urinary excretion values could be maintained in a normal range up to the end of the experiment, showing that renal calcium handling in dogs with experimentally induced renal failure seems to differ from that observed in human patients.     

Adjuvant effect of green propolis on humoral immune response of bovines immunized with bovine herpesvirus type 5

Despite recent technological advances in vaccine production, most vaccines depend on the association with adjuvant substances. In this study, propolis, which has been attracting the attention of researchers due to its bioactive properties, was evaluated as an immunological adjuvant. The association of 40mg/dose of an ethanolic extract of green propolis with an inactivated oil vaccine against bovine herpesvirus type 5 (BoHV-5), resulted in a significant increase (P<0.01) in the neutralizing antibody levels, comparing to the bovines that received the same vaccine without propolis. Besides, propolis increased the percentage of animals with high antibody titers (above 32). Phenolic compounds such as artepillin C (3,5-diprenyl-4-hydroxycinnamic acid) and the derivatives of cinnamic acid besides other flavonoid substances were abundant in the propolis extract used, and they could be the main substances with adjuvant action. The effect of the green propolis extract on the humoral immune response can be exploited in the development of new vaccines.     

Ochratoxin A on green coffee: influence of harvest and drying processing procedures

Ochratoxin A is a metabolite produced by Aspergillus and Penicillium species that is nephrotoxic and possibly carcinogenic to humans. The aim of this study was to evaluate ochratoxin A contamination in green coffee obtained by different harvesting and drying operations and from fruits of different ripening stages in order to identify hazards. The research was directed to coffees from the highland area of Rio de Janeiro state (Brazil), which is traded in the domestic market. Twenty-two out of 54 samples contained ochratoxin A at levels ranging from 0.3 to 160 microg/kg. Ochatoxin A contamination levels between different ripe stage fruits were not significant (P > 0.05). "Varri??o" coffee, consisting of fruits that fell from the tree spontaneously and stayed longer on the ground before being harvested, was the most contaminated. Eleven out of 14 samples of varri??o coffee were contaminated. Three out of 10 samples from the northwestern region of the state were positive for ochratoxin at levels ranging from 10.1 to 592 microg/kg. The contaminated samples had in common the fact that they were harvested directly from the soil.     

Influence of condensed tannin on intake, digestibility, and efficiency of protein utilization in beef steers fed high concentrate diet

This trial was conducted to evaluate if the effect of condensed tannin (CT) is associated with a true protein source on intake, ruminal and total digestibility, ruminal digestion rate, protein efficiency, and microbial efficiency in beef steers fed high concentrate diet (87% of DM). Four Bos indicus steers (407 ± 12 kg of BW) fitted with rumen cannula were assigned to a 4 × 4 Latin square design, arranged in a 2 × 2 factorial arrangement. Treatments consisted of either inclusion (0.4% of DM) or exclusion of condensed tannin (CT) from quebracho extract (76% of CT) with or without the use of soybean meal (SBM) as source of true protein. The level of inclusion was calculated to provide a daily intake of 1 g/10 kg of BW of CT. Intake of DM and nutrients was not affected (P > 0.10) by CT inclusion. However, there was an effect (P < 0.10) of CT inclusion on ether extract digestibility. An interaction (P < 0.10) was observed between CT and SBM on ruminal digestibility and digestion rate of crude protein (CP): when mixed with soybean meal, CT decreased the ruminal digestibility and, consequently, reduced the digestion rate of CP. Intake of CP increased (P < 0.10) with the inclusion of SBM. No differences in DM passage rate were observed (P > 0.10) among treatments. Effects of the interaction (P < 0.10) between CT and SBM were observed on flux of rumen undegradable protein (RUP), metabolizable protein (MP), and on the ratio MP:CP. In the presence of soybean meal, the addition of CT increased (P < 0.10) the flux of RUP and MP, and improved the ratio MP:CP. The yield of microbial protein on the abomasum and the microbial efficiency did not differ among treatments (P > 0.10). There was no difference (P > 0.10) on the pH, VFA, and ruminal ammonia (N-NH₃) with the addition of condensed tannin. The N-NH₃ increased and the ruminal pH decreased with the inclusion of soybean meal (P < 0.10). The utilization of condensed tannin as an additive in beef cattle diets with high level of concentrate and soybean meal as a source of true protein implies positive effects on crude protein utilization, decreasing digestion rate and ruminal digestibility of crude protein and consequently increasing the levels of metabolizable protein, with no changes in the ruminal fermentation parameters.     

Hemorrhagic disease in dogs infected with an unclassified intraendothelial piroplasm in southern Brazil

A hemorrhagic disease affecting dogs in Brazil, referred to popularly as "nambiuvú" (bloody ears) and believed to be transmitted by ticks, has been observed in animals infected with an organism described originally in 1910 as a piroplasm, and known locally as Rangelia vitalli. In this series of 10 cases, the disease was characterized by anaemia, jaundice, fever, spleno- and lymphadenomegaly, hemorrhage in the gastrointestinal tract, and persistent bleeding from the nose, oral cavity and tips, margins and outer surface of the pinnae. The ixodid ticks Rhipicephalus sanguineus and Amblyomma aureolatum infested affected dogs from suburban and rural areas, respectively. Laboratory findings included regenerative anaemia, spherocytosis, icteric plasma and bilirubinuria. Those intracellular organisms were found in bone marrow smears but not in blood smears. Microscopically, zoites were seen within the cytoplasm of blood capillary endothelial cells. Parasitized and non-parasitized endothelial cells were positive immunohistochemically for von Willebrand factor (vWF). Langhans-type multinucleate giant cells were observed in the lymph nodes and choroid plexus. There was prominent erythrophagocytosis by macrophages in the lymph node sinuses and infiltration of the medullary cords by numerous plasma cells. Ultrastructurally, this organism had an apical complex that included a polar ring and rhoptries but no conoid. This parasite was contained within a parasitophorous vacuole that had a trilaminar membrane with villar protrusions and was situated in the cytoplasm of capillary endothelial cells. This organism tested positive by immunohistochemistry for Babesia microti. This pathogen was also positive by in situ hybridization for B. microti. Tentative clinical diagnosis in these cases was based on the history, clinical picture, haemogram and favorable response to therapy, and confirmed through microscopic examination of smears from the bone marrow or histological sections of multiple tissues, especially lymph nodes where zoites were most frequently found. The disease was reproduced by intravenous inoculation of blood from a naturally infected dog into an experimental dog. The authors demonstrate in this study that this organism is a protozoa of the phylum Apicomplexa, order Piroplasmorida. This piroplasm seems to be different from Babesia since it has an intraendothelial stage. Molecular phylogenetic analysis is necessary to better characterize this parasite and clarify its taxonomic status.     

Effects of long-term dietary supplementation of monensin or saccharomyces cerevisiae on blood acid-base and productive performance in growing feedlot steers

The aim of this study was to evaluate the effects of two dietary supplements (monensin and a live yeast culture) on acid-base balance in steers maintained in a commercial feedlot system, considering effects over the growing period (14 to 23 weeks of age). A 63-day feedlot study was performed using 42 double-muscled Belgian Blue steers. Steers were allotted randomly to one of the three study groups: (1) control group [no supplementation, C], (2) monensin supplementation [MON] at a concentration of 30 mg/kg (DM basis), and (3) live Saccharomyces cerevisiae strain supplementation [SACC] at a dose of 500 mg/kg (DM basis).Venous blood samples were collected for the measurement of acid-base parameters and L-lactate. Production parameters were also used as a complementary tool for understanding the internal changes associated with supplementation. Our results show that during the study period no statistical differences were observed between supplemented and control steers, although non-supplemented animals tended to gain more efficiently than those fed monensin or yeast. Nevertheless, taking into account blood parameters, these control animals showed a greater risk of acid overload due to a more marked decline in blood buffer levels over time in comparison with supplemented steers although no differences were observed between monensin or yeast supplemented animals. Additionally, significant effect of supplementation was observed in packed cell volume (PCV) values.     

Characterization of single‐nucleotide polymorphism markers in the Mediterranean mussel,Mytilus galloprovincialis

The Mediterranean mussel, Mytilus galloprovincialis, is one of the most important aquaculture species in Europe. Appropriate molecular markers are required to evaluate genetic resources and to trace genealogies in breeding programmes for improving mussel culture. Microsatellites have been commonly applied to this purpose in other species. However, Mediterranean mussel microsatellites have demonstrated high frequencies of null alleles that hamper accurate estimates of population parameters and confident parentage inferences. As alternative markers, we have characterized in silico 25 potential single‐nucleotide polymorphism (SNP) markers in the Mediterranean mussel from expressed sequence tag (EST) public databases. The genotyping of SNPs was performed using a single‐base extension approach. Their polymorphism was evaluated in 47 individuals from an Atlantic population. Out of the 25 potential SNPs tested, 12 were technically feasible (producing a single amplicon) and polymorphic. All were biallelic and had an unbiased heterozygosity ranging from 0.160 to 0.504. One SNP was from a mitochondrial gene. The combined potential of nuclear SNPs for parentage assignment gave an exclusion probability of a false couple of parents of 0.9471. These markers will be useful for evaluating resources and tracing genealogies in genetic breeding programmes implemented to solve the main problems of mussel culture.     

Laser-based spectroscopic methods to evaluate the humification degree of soil organic matter in whole soils: a review

Purpose

The objective of this review is to survey critically the results obtained by the application of laser-induced fluorescence spectroscopy (LIFS) and laser-induced breakdown spectroscopy (LIBS) to the evaluation of the humification degree (HD) of soil organic matter (SOM) directly in untreated, intact whole soils.

Materials and methods

A large number of soils of various origin and nature, either native or under various cultivations, land use, and management, at various depths, have been studied to evaluate the HD of their SOM directly in intact whole samples. The LIFS spectra were obtained by either a bench or a portable argon laser apparatus that emits UV-VIS light of high power, whereas the LIBS spectra were obtained using a Q-switched Nd:YAG laser at 1064 nm.

Results and discussion

The close correlations found by comparing H_LIF values of whole soil samples with values of earlier proposed humification indexes confirmed the applicability of LIFS to assess the HD of SOM in whole soils. The high correlation found between HD_LIBS values and H_LIF values showed the promising potential of LIBS for the evaluation HD of SOM.

Conclusions

The LIFS technique shows to be a valuable alternative to evaluate the HD of SOM by probing directly the whole solid soil sample, thus avoiding the use of any previous chemical and/or physical treatments or separation procedures of SOM from the mineral soil matrix. The emerging application of LIBS to evaluate the HD of SOM in whole soils appears promising and appealing due to its sensitivity, selectivity, accuracy, and precision.

     

Net requirements of calcium, magnesium, sodium, phosphorus, and potassium for growth of Nellore × Red Angus bulls, steers, and heifers

A comparative slaughter trial was conducted to assess the net requirements for gain of Ca, P, Na, K and Mg of bulls, steers and heifers of Nellore and Red Angus crossbreds. Twenty seven F1 Nellore and Red Angus crossbred calves (9 steers, 9 bulls, and 9 heifers), averaging 274 kg BW, were used. At the beginning of the trial, three animals from each gender were slaughtered to determine the initial body composition. The remaining 18 animals (3 animals of each gender) were randomly assigned to two treatments: fed 0.75 or 1.5% of BW of concentrate. The diets were based on corn silage and were isonitrogenous (2% N, DM). After three growing periods of 28 d, all animals were slaughtered. The cleaned gastrointestinal tract, organs, carcass, head, hide, tail, feet, and tissues were weighed to determine the empty BW (EBW). These parts were ground separately and subsampled for chemical analyses. The log of the contents of each mineral in the empty body was regressed on the log of the EBW to estimate the net requirement for each mineral per kg of empty body gain (EBG). There were no differences (P > 0.05) in the net requirements for growth of all macrominerals among genders. The equations of the pooled data of the net requirements for growth (g/kg EBG) were: 332.6 × EBW ^− 0.6367 for Ca, 112.1 × EBW ^− 0.5615 for P, 10.85 × EBW ^− 0.3992 for Na, 4.01 × EBW ^− 0.153 for K, and 3.589 × EBW ^− 0.462 for Mg. Our findings indicated that retained Ca and retained P were poorly related to the retained protein.