Acid–Base Changes in Canine Neonates Following Normal Birth or Dystocia

There are limited data concerning blood gas parameters in neonatal dogs. Knowledge of the normal physiology may facilitate effective therapeutic intervention and potentially reduce neonatal mortality. This study examined acid–base parameters in pups born at normal parturition (n = 27) compared with those born after obstetrical assistance or caesarean operation (n = 13) and those born following oxytocin (OXY) administration for treatment of uterine inertia (n = 11). Pups were subjected to an objective scoring method of neonatal health adapted from use in humans (the Apgar score) at birth and again at 5 and 60 min after birth. Venous blood samples were collected at 5 and 60 min after birth for evaluation of blood gas parameters. At birth, all pups had low Apgar scores and a mixed acidosis. The base excess was lowest for pups delivered after OXY administration. The Apgar score improved for all pups after 5 min of birth and there was an improvement in carbon dioxide tension, base excess and venous blood pH at 1 h, although in all pups a metabolic acidosis persisted. These data provide an important insight into neonatal physiology and the variability of blood gas parameters in pups born at normal and abnormal parturition and provide the basis for clinical decision making following dystocia.     

Systemic alterations of bovine hemostasis due to Rhipicephalus (Boophilus) microplus infestation

The tick Rhipicephalus (Boophilus) microplus is a hematophagous ectoparasite that causes considerable economic losses to cattle breeding. Although R. microplus saliva contains several molecules that interfere with the blood coagulation process, so far the systemic alterations in the host hemostatic system have not been described. This study aims to determine if R. microplus infestation induces any disturbance to the host’s hemostatic system. To address these questions, six calves were experimentally infested with 20,000 R. microplus larvae and their blood was collected before and 7, 14 and 21 days post-infestation. Collagen and ADP-induced platelet aggregation as well as coagulation (activated partial thromboplastin time and prothrombin time) decreased in infested bovines. Platelet blood count and fibrinogen increased during the course of infestation, probably as a compensatory response. These alterations may play a role in host health status, and show that the host cannot fully counteract the tick anti-hemostatic mechanisms.     

Distribution of antibodies against porcine circovirus type-2 (PCV2) in single site and multi-site farrow-to-finish farms in Brazil

A comparative serologic study was performed in seven single site (SS) farrow-to-finish farms and four multi-site (MS) farrow-to-finish farms, with or without post-weaning multisystemic wasting syndrome (PMWS). In each farm, 30 blood samples were collected for each category of the production cycle: sows, farrowing crate, nursery, grower pigs, and finishing pigs. Sera were evaluated for the presence of antibodies to porcine circovirus type-2 (PCV2) via immunoperoxidase monolayer assay. Serologic profiles for PCV2 were different between SS and MS farms. Seroconversion following the decline in maternal antibodies occurred at a later stage on SS farms (grower pigs) than MS farms (nursery pigs). MS farms tended to have lower antibody titers than SS farms in the categories of sow, piglet, and nursery, while higher antibody titers were found in grower pigs. Characterization of serologic profiles for different farms may provide important information for the adoption of vaccination programs.     

Virulence factors in Escherichia coli strains isolated from urinary tract infection and pyometra cases and from feces of healthy dogs

The aim of this study was to compare the prevalence of virulence genes in 158 Escherichia coli strains isolated from 51 clinical cases of UTIs, 52 of pyometra and from 55 fecal samples from healthy dogs by PCR. papC was found in 12 (23.5%) strains isolated from UTIs, 19 (36.5%) from pyometra and 10 (18.2%) from feces. papGII was observed in 3 (5.8%) strains from pyometra, and papGIII in 10 (19.6%) from UTIs, 15 (28.8%) from pyometra and 9 (16.4%) from feces. sfaS was detected in 22 (43.1%) strains from UTIs, 24 (46.1%) from pyometra and 19 (34.5%) from feces. hlyA was observed in 17 (33.3%) strains from UTIs, 18 (34.6%) from pyometra and 7 (12.7%) from feces, while cnf-1 was detected in 11 (21.6%) from UTIs, 21 (40.4%) from pyometra and 9 (16.4%) from feces. iucD was observed in 12 (23.5%) strains from UTIs, 9 (17.3%) from pyometra and 1 (1.8%) from feces. usp was found 17 (33.3%) isolates from UTIs and 36 (69.9%) from pyometra.     

Linear–threshold animal model for birth weight, gestation length and calving ease in United Kingdom Limousin beef cattle data

Breeding value evaluation for UK Limousin beef cattle data was carried out by multiple-trait linear–threshold animal model with variance components assumed to be known. Polychotomous calving ease with five categories was analysed with two continuous traits: birth weight and gestation length. Field data consisted of 220,799 animals with observations with every possible combination of traits, and 270,035 animals in the pedigree. The threshold model was solved either with Newton Raphson or Expectation Maximisation algorithm, and solutions were compared to evaluation by a linear model with original and normalised scores. There were insignificant differences in solutions between the two algorithms for threshold model analyses. Furthermore, solutions of the continuous traits were similar by the threshold and linear models. For the categorical trait, correlations for random effects from the threshold and linear models were high. In case of normalised scores (original scores case in brackets) correlations with solutions from the threshold and linear model were 0.97 (0.94) and 0.97 (0.93) for direct and maternal genetic effects and 0.95 (0.89) for permanent maternal effects. Even so, at least one third of the top 1% ranking of bulls differed between the linear and the threshold models. Predictive abilities as correlations between estimated breeding values and pedigree indices were almost equal between the linear and threshold models for both continuous and categorical traits. In conclusion, despite the higher computational demand, the linear–threshold animal model can be seen worthwhile in the genetic evaluation of the national UK beef cattle data set.     

Degradation of Prototype Pesticides Submitted to Conventional Water Treatment Conditions: The Influence of Major Parameters

The behavior of several pesticides in aqueous solution, namely bifenthrin, amethrin (pyrethroid insecticides), endosulfan and endosulfan sulfate (organochlorine pesticides), disulfoton, methyl pyrimiphos, and phorate (organophosphorus pesticides), submitted to the conditions typically employed in water treatment stations was investigated. Continuous pesticide depletion was monitored by solid-phase microextraction sampling followed by gas chromatography–mass spectrometry analysis. The influence of major parameters (sodium hypochloride concentration, solution pH, and exposure time to ultraviolet (UV) light) was, thus, adequately established via two complementary approaches: factorial (2³, three variables—two levels) and Doehlert designs. Hence, the sodium hypochloride concentration and the solution pH produced distinct effects depending on the pesticide evaluated (for instance, acidic and basic media caused increasing rates of degradation for the organophosphorus/pyrethroid and organochlorine pesticides, respectively). Conversely, higher rates of degradation were achieved for all of the pesticides investigated when increased exposure times to UV radiation were employed. Finally, the exposure time to UV radiation that lead to complete degradation of disulfoton and endosulfan sulfate (organophosphorus and organochlorine pesticides, respectively) in aqueous media under ordinary conditions employed in water treatment stations was established; disulfoton and endosulfan sulfate were completely degraded after 10 and 40 h, respectively.     

The role of arbuscular mycorrhizal fungi and cattle manure in the establishment of Tocoyena selloana Schum. in mined dune areas

In mined dune areas, revegetation with manured seedlings of native species is a common practice. Establishment of mycorrhized Tocoyena selloana seedlings in the mined coastal sand dunes of Northeast Brazil was tested. In greenhouse, seedlings were grown in substrates with 0, 5, 10, 15 or 20% cattle manure proportions and inoculated with Acaulospora longula, a mixture of native arbuscular mycorrhizal fungi (AMF) or uninoculated. The seedlings responded positively to the inoculation, but growth was limited in the absence of manure, independently of inoculation, and was higher with fertilizing doses ≥10%. The seedlings transplanted to the field were grown in a substrate with 16.5% manure and inoculated with A. longula or Gigaspora albida. After 13 months, 19 AMF species were identified in the rhizosphere and the inoculated plants were more colonized than those uninoculated. Plants associated to G. albida were taller and those associated to A. longula had a tendency of higher biomass than the uninoculated ones. Even though this tendency was not statistically significant, considering the effect on height and the low cost of inoculation it may be a feasible practice to maximize environment restoration.     

Higher breeding densities of the threatened little bustard Tetrax tetrax occur in larger grassland fields: Implications for conservation

Previous studies have found that densities of little bustard Tetrax tetrax breeding males tend to be higher in areas with smaller agricultural fields, presumably due to increased habitat diversity. However, exceptionally high densities have been found in large grassland fields in Portugal, which suggests that the influence of field size varies geographically, and that the role of this factor is not yet fully understood, despite its importance as a key management issue.We studied how field size, together with vegetation structure, influences the presence and density of breeding little bustards in a region of southern Portugal. Fifty-four grassland fields were sampled in 2007 and another 29 in 2008, with sizes ranging from 23 to 172 ha. A total of 183 breeding males were found in 47 of these fields, reaching densities of up to 37 males/100 ha. A higher probability of occurrence of breeding males was found in larger fields with a vegetation height below 40 cm and field size alone explained 46% of the variability in male density. These results suggest that larger continuous areas of suitable habitat attract many males, most likely as a consequence of their lek mating system. We conclude that conservation efforts, in a landscape context of large farm sizes, should: (1) be channelled to farms with large fields; (2) ensure adequate livestock grazing to create suitable habitat and (3) promote management at a landscape level to ensure the most continuous grassland habitat patches possible.