Gastrointestinal parasitism reduces the plasma availability of doramectin in lambs

A study was undertaken to investigate the effect of parasitism on plasma availability and pharmacokinetic behaviour of doramectin (DRM) in lambs. Fourteen parasitised grey face Suffolk lambs (26.9 ± 1.5 kg bodyweight) were selected for the study. Seven pairs of lambs were allocated to two groups to obtain an approximately even weight distribution. Group I (non-parasitised) was pre-treated with three repeated administrations of 5 mg/kg fenbendazole to maintain a parasite free condition. In group II (parasitised), the lambs did not receive any anthelmintic treatment. After the 85-day pre-treatment period, both groups of animals were treated with DRM by subcutaneous (SC) injection in the shoulder area at 200 μg/kg. Throughout the experimental period, both groups were maintained together under similar feeding and management conditions. Blood samples were collected by jugular venepuncture at different set times between 0.5 h and 60 days post-treatment. After plasma extraction and derivatisation, samples were analysed by high performance liquid chromatography (HPLC) with fluorescence detection. A computerised kinetic analysis was performed and the data were compared using the Student’s paired t test.The parent molecule was detected in plasma between 30 min and either day 20 (parasitised) or day 35 (non-parasitised) post-DRM treatment. The AUC values of the parasitised group (143.0 ± 18 ng d/mL) were significantly lower (P < 0.05) than those observed in the parasitically naïve animals (229.6 ± 21.7 ng d/mL). The mean residence time (MRT) in the parasitised group (3.4 ± 0.3 days) was significantly shorter (P < 0.05) than in the healthy group (6.6 ± 0.6 days). Study results have shown that parasitic disease, through alteration in the body condition, can produce significant changes in the plasma disposition of DRM when administered SC to parasitised lambs.     

Protective activity against oocyst shedding in cats vaccinated with crude rhoptry proteins of the Toxoplasma gondii by the intranasal route

This study evaluated a vaccine made from crude rhoptry proteins of Toxoplasma gondii with Quil-A, which was administered to cats by the intranasal route. Eleven short-hair domestic cats were divided into four groups: G1 (n=3) received three doses (200 microg/dose) of the rhoptry vaccine with Quil-A (20 microg); G2 (n=3) received PBS with Quil-A (20 microg); G3 (n=3) and G4 (n=2) received only PBS. Treatments were administered at days 0, 21, and 42 by the intranasal route. Challenge was done to G1, G2, and G3 animals with 600 cysts of the VEG strain on day 51 (challenge day); G4 animals were unchallenged. The anti-T. gondii IgG and IgA antibody levels from sera were measured by indirect enzyme-linked immunosorbent assay (ELISA). At challenge, two animals from G1 revealed antibody levels for both IgG and IgA; oocysts were not detected in feces of these two cats. There were no differences in hematological values between groups throughout the experiment (p>0.10). Preventable fractions were 67% in G1 and 0% in G2 and G3. Comparatively, G1 animals shed 89.3% and 90.8% less oocysts than G3 and G4, respectively. Two out of three cats were protected against T. gondii oocyst shedding when the rhoptry vaccine was administered by the intranasal route. This is the first study using crude rhoptry proteins as vaccine by the intranasal route in cats to evaluate protection against oocysts shedding.     

Effects of exogenous amylase on the in vitro digestion kinetics of whole-crop maize silages made from flint or dent grain type at different phenological stages grown in tropical condition

The effect of exogenous amylase on the in vitro rumen digestion kinetics of whole-crop maize silage made from dent (RB9004) or flint grain type (RB9308) was evaluated at different phenological stages: soft dough (SOD), early dent (EAD), ½ milkline (½M) and ¾ milkline (¾M). Forage was harvested from 70 to 110 days after sowing. Two rumen-cannulated cows receiving or not exogenous amylase (0.7 g/kg dry matter—DM, provided to achieve 396 kilo Novo units of amylase activity/kg of TMR DM) were used as donor of ruminal fluid. The in vitro gas production kinetics was evaluated according to a dual-pool logistic model. The chemical composition and gas production kinetics were affected by the hybrid and phenological stages. The flint hybrid had lower range for chemical analysis among physiological stages. Harvesting at ½M and ¾M improved DM content, bromatological composition and silage quality parameters compared to dent or flint types. Amylase (i) increased methane (CH₄) production and in vitro dry matter digestibility (IVDMD) in ½M stage, (ii) improved digestion kinetics by reducing lag time and increasing total gas production and fermentation rates of non-fibrous carbohydrates (NFC) and fibrous carbohydrates (FC), and (iii) increased extent and fermentation rate of NFC and increased fermentation rate of FC fraction in whole-crop maize silages produced from dent or flint types in all phenological stages. Harvesting between ½M and ¾M is the best phenological stage to improve chemical composition and silage quality parameters. Exogenous amylase showed improvements on fibre digestion of silages at ½M and ¾M phenological stages in both grain types of corn.     

A multiple-phenotype imputation procedure as a method for prediction of cheese-making efficiency in Spanish Assaf sheep

Sheep milk is mainly intended to manufacture a wide variety of high-quality cheeses. The ovine cheese industry would benefit from an improvement, through genetic selection, of traits related to the milk coagulation properties (MCPs) and cheese yield-related traits, broadly denoted as “cheese-making traits.” Considering that routine measurements of these traits needed for genetic selection are expensive and time-consuming, this study aimed to evaluate the accuracy of a cheese-making phenotype imputation method based on the information from official milk control records combined with the pH of the milk. For this study, we analyzed records of milk production traits, milk composition traits, and measurements of cheese-making traits available from a total of 1,145 dairy ewes of the Spanish Assaf sheep breed. Cheese-making traits included five related to the MCPs and two cheese yield-related traits. The milk and cheese-making phenotypes were adjusted for significant effects based on a general linear model. The adjusted phenotypes were used to define a multiple-phenotype imputation procedure for the cheese-making traits based on multivariate normality and Markov chain Monte Carlo sampling. Five of the seven cheese-making traits considered in this study achieved a prediction accuracy of 0.60 computed as the correlation between the adjusted phenotypes and the imputed phenotypes. Particularly the logarithm of curd-firming time since rennet addition (logK₂₀) (0.68), which has been previously suggested as a potential candidate trait to improve the cheese ability in this breed, and the logarithm of the ratio between the rennet clotting time and the curd firmness at 60 min (logRCT/A60) (0.65), which has been defined by other studies as an indicator trait of milk coagulation efficiency. This study represents a first step toward the possible use of the phenotype imputation of cheese-making traits to develop a practical methodology for the dairy sheep industry to impute cheese-making traits only based on the analysis of a milk sample without the need of pedigree information. This information could be also used in future planning of specific breeding programs considering the importance of the cheese-making efficiency in dairy sheep and highlights the potential of phenotype imputation to leverage sample size on expensive, hard-to-measure phenotypes.     

Reproductive outcomes of anestrous goats supplemented with spineless Opuntia megacantha Salm-Dyck protein-enriched cladodes and exposed to the male effect

Tropical Animal Health and Production - The possible influence of the “male effect” upon reproductive outcomes of adult anestrous goats under marginal rangeland conditions and...     

Detection of enzootic nasal tumor virus (ENTV) in a sheep flock in southern Brazil

Enzootic nasal tumor (ENT) is a contagious neoplasm associated with enzootic nasal tumor virus (ENTV), which may induce disease in sheep (ENTV-1) and goats (ENTV-2). This study aimed to describe the occurrence of ENT in two Texel sheep (Ovis aries) from a 75-sheep flock, located in the city of Gravataí, southern Brazil. Animals used to be purchased from different origins, and no specific tests for disease monitoring or quarantine procedure were performed. Affected animals presented respiratory distress, anorexia with severe weight loss, and mucopurulent unilateral nasal discharge. Necropsy was performed in both animals and nasal cavity masses were observed. Histopathological analysis demonstrated an epithelial neoplasm compatible with nasal adenocarcinoma. PCR using a protocol that amplifies a 591 bp sequence of 5’LTR-gag region of ENTV1 was performed followed by DNA sequencing. Both samples were positive, and the sequences obtained presented highest identity (97%) with ENTV strain TN28 (GenBank accession number MH899613) detected in a Texel sheep from Scotland. This is the first report of ENTV-1 leading to enzootic nasal tumor in sheep in Latin America, which confirms the presence of the retrovirus in sheep flocks in the Brazilian territory.

     

Organic additives used in beef cattle feedlot: Effects on metabolic parameters and animal performance

Organic additives are recently being used in animal diets owing to their ability to control metabolic issues and result in better animal performance. Specifically, the organic additive Fator P^® presents an additional advantage that is to cause a lesser greenhouse gas emission. This study evaluated whether Fator P^® intake changes ruminal parameters or animal performance of beef cattle. Evaluations were carried out in a feedlot experiment divided into growing (46 days; two diets [control mix—CM and standard mix—SM] and finishing (lasted 83 days; four diets: CM, SM, Fator P^® + virginiamycin, and Fator P^® alone [FP]) trials. Animal performance study involved 48 animals allocated to 12 collective pens in completely randomized experimental design. Ruminal parameters were evaluated in separate metabolism study developed carried out using individual pen with four steers. During growing trial, FP diet resulted in higher (p < 0.05) dry matter intake (DMI) and ruminating time. In the finishing trial, diets containing Fator P^® resulted in higher DMI than obtained with CM. Most of the ruminal parameters did not differ (p > 0.05) among dietary treatments. Therefore, Fator P^® represents a viable and safe strategy for supplementation to beef cattle finished using high‐concentrate diet in feedlot systems.     

Escherichia coli lipopolysaccharides and Staphylococcus aureus enterotoxin B differentially modulate inflammatory microRNAs in bovine monocytes

MicroRNAs (miRNAs) are a family of regulatory molecules involved in many physiological processes, including activation of cells of the immune system. This study investigated the effect of Escherichia coli lipopolysaccharide (LPS) and Staphylococcus aureus enterotoxin B (SEB) on the expression of five miRNAs involved in the inflammatory response, including miR-9, miR-125 b, miR-155, miR-146 a and miR-223, in bovine CD14(+) cells (monocytes). Incubation of monocytes with SEB induced down-regulation of miR-155, miR-223 and miR-125 b, but not the anti-inflammatory miRNA miR-146 a. Conversely, incubation with LPS upregulated both miR-155 and miR-146 a. In vitro incubation of isolated CD14(+) bovine monocytes with LPS and SEB elicited different and opposite expression of miRNAs reportedly involved in inflammatory reactions.     

Transcranial Doppler sonographic findings in granulomatous meningoencephalitis in small breed dogs

Granulomatous meningoencephalitis (GME) is an acute, progressive, and often fatal inflammatory disease of the central nervous system, affecting mainly small and toy dog breeds. A definitive diagnosis of GME can only be achieved through histopathologic examination of samples collected after death. This retrospective study describes transcranial Doppler ultrasonography (TDS) findings in dogs with confirmed clinical histopathology of GME. Eleven dogs were selected for this study. Sonographic findings in B-mode demonstrated diffuse decreased brain parenchyma echogenicity in 9 dogs, ventriculomegaly in 8 dogs, brain atrophy in 4 dogs, and hyperechoic focal lesions in 6 dogs. Color Doppler imaging revealed more obvious vessels of the arterial circle in 10 dogs. Spectral Doppler examination was performed in 10 dogs to detect the 6 major cerebral arteries of interest. The examination showed normal and high resistive index (RI) values in the outlined arteries. The TDS findings were consistent with pathology found on postmortem examination.