Castor beans hulls as a replacement for Tifton 85 hay in lamb diets

The objective of this study was to evaluate the effect of replacing Tifton 85 hay (0, 33, 66, or 100 %) with by castor bean hulls on the intake and nutrient digestibility and performance of 28 noncastrated lambs, averaging 7 months in age, 19.5?±?2.0 kg average live weight, fed on diets based on forage cactus. The animals were housed in individual pens for 100 days. The digestibility trial occurred 40 days after the start of the performance using LIPE® as an external indicator for estimating fecal dry matter production. The replacement of hay with Castor beans hulls linearly decreased the intakes of dry matter, neutral detergent fiber, organic matter, and crude protein and reduced the digestibility coefficients of the dry matter, neutral detergent fiber, organic matter content, crude protein, and total digestible nutrient content. The hot carcass and true carcass yields were not influenced by the treatments and the feed conversion increased linearly. The empty body weight, live weight at slaughter, hot and cold carcass weights, total gain, and average daily gain decreased linearly with the replacement. The replacement of Tifton 85 hay with castor bean hulls reduced the intake of dry matter, crude protein and energy, consequently reducing the performance of the animals. However, as the regression coefficients were of low magnitude, data were subjected to analysis of variance and means were compared using the Dunnett test with diet without castor bean hulls set as the control treatment. The Tifton 85 hay can be replaced up to 66 % by castor bean hulls in finishing diets for lambs.     

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.     

Effect of Auditory Stimulation During Early Development in Puppy Testing of Future Police Working Dogs

The aim of this study was to determine if the use of auditory stimulation during early development stages of young puppies, using a variety of sounds such as music, radio talk shows, and ambient noise, that included car noises, sirens, and gunshots, could affect the results of early puppy testing of future police working dogs. Sixty-seven puppies at 7 weeks of age were submitted to a 9-situation test and their results analyzed. The sample comprised 34 males and 33 females, from 4 different breeds/crosses (27 German Shepherd Dog, 19 Belgian Malinois Shepherd Dog, 7 Dutch Shepherd Dog, and 14 animals of a cross of German Shepherd Dog with Belgian Malinois Shepherd Dog), representing 12 litters. Puppies were divided in 2 groups, G1 (n?=?46) and G2 (n?=?21), with G1 being submitted only to the standard socialization protocol in use in the Grupo de Intervenção Cinotécnico while puppies in G2, beside the standard socialization protocol, were also presented with auditory stimulation throughout the day, particularly during playtime and meal time. Significant differences were observed in some situations between groups, with puppies in G1 achieving better scores on this specific test, which aims to access a puppy's level of interaction with humans, reaction to manipulations, and reaction to different environmental stimulus. No differences were found between sexes but some differences between breeds were found, suggesting familial effects on noise reaction. Further studies, involving a greater number of puppies and litters, and that would also include noise exposure quantification, behavioral, and physiological assays are required to confirm these findings. It will also be of interest to evaluate if the results obtained as a young puppy have any connection with future adult performance.     

An iron-acquisition-deficient mutant of Corynebacterium pseudotuberculosis efficiently protects mice against challenge

Caseous lymphadenitis (CLA) is a chronic disease that affects sheep and goats worldwide, and its etiological agent is Corynebacterium pseudotuberculosis. Despite the economic losses caused by CLA, there is little information about the molecular mechanisms of bacterial pathogenesis, and current immune prophylaxis against infection has been unable to reduce the incidence of CLA in goats. Recently, 21 different mutant strains of C. pseudotuberculosis were identified by random mutagenesis. In this study, these previously generated mutants were used in mice vaccination trials to develop new immunogens against CLA. Based on this analysis, {"type":"entrez-nucleotide","attrs":{"text":"CZ171053","term_id":"58296493","term_text":"CZ171053"}}CZ171053, an iron-acquisition-deficient mutant strain, was selected. After challenge with a virulent strain, 80% of the animals that were immunized with the {"type":"entrez-nucleotide","attrs":{"text":"CZ171053","term_id":"58296493","term_text":"CZ171053"}}CZ171053 strain survived. Furthermore, this vaccination elicited both humoral and cellular responses. Intracellular survival of the bacterium was determined using murine J774 cells; in this assay, the {"type":"entrez-nucleotide","attrs":{"text":"CZ171053","term_id":"58296493","term_text":"CZ171053"}}CZ171053 had reduced intracellular viability. Because iron acquisition in intracellular bacteria is considered one of their most important virulence factors during infection, these results demonstrate the immunogenic potential of this mutant against CLA.