The influence of anti-inflammatory therapy on bacterial clearance following intramammary Escherichia coli challenge in goats

Exploring differentially expressed genes associated with coat color in goat skin using RNA-seq

Fur color in domestic goats is an important, genetically determined characteristic that is associated with economic value. This study was designed to perform a comprehensive expression profiling of genes expressed in the skin tissues from Laiwu Black goat and Lubei White goat. Comparisons of black and white goat skin transcriptomes revealed 102 differentially expressed genes (DEGs), of which 38 were upregulated and 64 downregulated in black skin compared with white skin. Among the DEGs, we identified six genes involved in pigmentation, including agouti signaling protein (ASIP), CAMP responsive element binding protein 3-like 1 (CREB3L1), dopachrome tautomerase (DCT), premelanosome protein (PMEL), transient receptor potential cation channel subfamily M member 1 (TRPM1), and tyrosinase-related protein 1 (TYRP1). Notably, there were no significant differences in the expression of melanocortin 1 receptor, microphthalmia-associated transcription factor, tyrosinase, and KIT proto-oncogene receptor tyrosine kinase between the black and white skin samples, whereas ASIP expression was detected only in white skin. PMEL, TRPM1, TYRP1, and DCT showed higher expression in black goat skin, but ASIP and CREB3L1 had higher expression in white goat skin. Quantitative polymerase chain reaction results for PMEL, TRPM1, DCT, TYRP1, and CREB3L1 expression were consistent with those for RNA-seq. These results will expand our understanding of the complex molecular mechanisms of skin physiology and melanogenesis in goats, and provide a foundation for future studies.

Effect of acute stressors, adrenocorticotropic hormone administration, and cortisol release on milk yield, the expression of key genes, proliferation, and apoptosis in goat mammary epithelial cells

Cortisol is essential to milk synthesis; however, different acute stressors and the exogenous administration of adrenocorticotropic hormone (ACTH) decrease milk yield. Therefore, the effect of cortisol on milk yield and its influence on the survival of mammary epithelial cells have not been fully elucidated. In this context, the objective of this study was to evaluate the effect of cortisol on the expression of growth hormone receptor (GHR), insulin-like growth factor type 1 (IGF1), insulin-like growth factor type 1 receptor (IGF1R), insulin-like growth factor-binding protein 3 and 5 (IGFBP3 and IGFBP5), BAX, and BCL2 genes on the proliferation and apoptotic rates of mammary epithelial cells, and on milk yield in Saanen goats. In the present study, 3 experiments were conducted: (1) comparing the in vivo effects of first milking, vaccination, vermifugation, preventive hoof trimming, and the administration of ACTH or a placebo on cortisol release in dairy goats; (2) studying the in vivo effects of immediate increases in cortisol on the mammary gland of lactating goats; and (3) studying the in vitro effects of a prolonged increase in cortisol on mammary epithelial cells obtained from lactating goats. Cortisol release by goats increased significantly after ACTH administration compared with that observed after a placebo, and the cortisol profiles after first milking, vaccination, vermifugation, hoof trimming, and ACTH administration were similar. However, there was no effect of the immediate increase in cortisol in vivo on IGF-1 release, milk yield, milk quality, or the apoptosis and proliferation rates, nor was there any effect on the expression of the target genes. Furthermore, no interaction was observed between IGF-1 and cortisol in either the in vivo or in vitro experiments. However, the addition of cortisol in vitro significantly increased the expression of the GHR and IGF1R genes, which stimulate cell proliferation, and the BAX gene, which causes apoptosis. These contrasting results can explain why cortisol did not change the rates of proliferation or apoptosis in epithelial cells. Indeed, cortisol supplementation in vitro did not change the number or apoptotic rate of epithelial cells over the course of 5 d. Finally, further studies must be performed to understand the effect of cortisol on the expression of the GHR, IGF1R, and BAX genes by epithelial cells and the roles of these genes in milk synthesis during early lactation.

Voltammetric Determination of Flunixin on Molecularly Imprinted Polypyrrole Modified Glassy Carbon Electrode

A novel electrochemical sensing approach, based on electropolymerization of a molecularly imprinted polypyrrole (MIPpy) film onto a glassy carbon electrode (GCE) surface, was developed for the detection of flunixin (FXN). The sensing conditions and the performance of the constructed sensor were assessed by cyclic, differential pulse and (DPV) square wave voltammetry (SWV). The sensor exhibited high sensitivity, with linear responses in the range of 5.0 to 50.0 µM with detection limits of 1.5 and 1.0 µM for DPV and SWV, respectively. In addition, the sensor showed high selectivity towards FXN in comparison to other interferents. The sensor was successfully utilized for the direct determination of FXN in buffalo raw milk samples.

Effect of morphine and flunixin meglumine on isoflurane minimum alveolar concentration in goats

OBJECTIVE

To determine the effect of morphine and flunixin meglumine on isoflurane (ISO) minimum alveolar concentration (MAC) in goats.

STUDY DESIGN

Prospective, randomized experimental study.

ANIMALS

Five adult, wether goats from 1 to 3 years in age, and weighing 24-65 kg.

METHODS

Anesthesia was induced using ISO, which was delivered via a mask. Goats were intubated and ventilated to maintain an end-tidal carbon dioxide concentration between 25 and 30 mm Hg (3.3-4 kPa). End-tidal ISO concentration was measured using an infrared analyzer. The baseline ISO MAC that prevented purposeful movement in response to clamping a claw was determined. Following baseline MAC determination, each goat received one of the following four treatments intravenously (IV): morphine (2 mg kg(-1)), flunixin (1.5 mg kg(-1)), flunixin (1.5 mg kg(-1)) plus morphine (2 mg kg(-1)) or saline, and the MAC was re-determined. Goats were studied at weekly intervals, and each goat received each treatment in a randomized fashion.

RESULTS

The baseline ISO MAC for the control treatment was 1.43%. Morphine reduced the MAC by 29.7%. Flunixin did not significantly decrease the MAC nor did it potentiate the effect of morphine on MAC. The quality of recovery was good in all cases.

CONCLUSIONS

Morphine (2 mg kg(-1), IV) significantly reduced the ISO MAC in goats and did not adversely affect the quality of recovery.

CLINICAL RELEVANCE

The use of morphine, at the dose studied, in association with ISO anesthesia, will allow a clinically significant reduction in the concentration of ISO required to maintain general anesthesia in goats.

Pharmacokinetics and pharmacodynamic effects of flunixin after intravenous, intramuscular and oral administration to dairy goats

The pharmacokinetics and the prostaglandin (PG) synthesis inhibiting effect of flunixin were determined in 6 Norwegian dairy goats. The dose was 2.2 mg/kg body weight administered by intravenous (i.v.). intramuscular (i.m.) and oral (p.o.) routes using a cross-over design. Plasma flunixin content was analysed by use of liquid chromatography and the PG synthesis was evaluated by measuring plasma 15-ketodihydro-PGF2alpha by a radioimmuno-assay. Results are presented as median (range). The elimination half-lives (t(1/2) x lambda) were 3.6 (2.0-5.0), 3.4 (2.6-6.8) and 4.3 (3.4-6.1) h for i.v., i.m. and p.o. administration, respectively. Volume of distribution at steady state (Vd(ss)) was 0.35 (0.23-0.4 1) L/kg and clearance (CL), 110 (60-160) mL/h/kg. The plasma concentrations after oral administration showed a double-peak phenomenon with the two peaks occurring at 0.37 (0.25-1) and 3.5 (2.5-5.0) h, respectively. Both peaks were in the same order of magnitude. Bioavailability was 79 (53-112) and 58 (35%-120)% for i.m. and p.o. administration, respectively. 15-Ketodihydro-PGF2, plasma concentrations decreased after flunixin administration independent of the route of administration.

Mastitis therapy and pharmacology

Mastitis remains the most frequent cause of antibacterial use on dairy farms and contributes to a substantial portion of total drug and veterinary costs incurred by the dairy industry. Ultimately, the best outcome of mastitis therapy is a positive effect on the amount of marketed milk harvested and long-term survival of the cow. This article describes the strategies of therapy for bovine mastitis, with an emphasis on antibacterial and anti-inflammatory therapy.

Adrenocorticotrophic hormone and dexamethasone failed to affect milk yield in dairy goats: comparative aspects

The ability of adrenocorticotrophic hormone (ACTH; single i.v. injection of 2.5IU/kg BW) and dexamethasone (single i.m. injection of 36mg/kg BW) to affect milk production was studied in mid-lactating Israeli Saanen goats. None of these treatments produced changes in milk yield and composition of the goats. The effects of ACTH on blood cortisol levels, and the effects of ACTH and dexamethasone on blood plasma concentrations of glucose, however, were consistent with previous reports in goats and cows. These responses suggest that ACTH and dexamethasone treatments produced their expected glucocorticoid effects. It is suggested that obstructing the axis: stress-ACTH-glucocorticoid-down regulation of milk yield, which was demonstrated in dairy cows, reflects the adaptation of goats to harsh conditions, and the selection pressure to produce milk under conditions which are considered stressful for other ruminants.

Pharmacokinetic parameters and milk concentrations of ketoprofen after administration as a single intravenous bolus dose to lactating goats

Six clinically normal lactating does were administered ketoprofen (2.2 mg/kg intravenously (i.v.)). Blood and milk samples were collected prior to and for 24 h after drug administration. Drug concentrations in serum and milk were determined by high performance liquid chromatography. Pharmacokinetic parameters from each goat were combined to obtain mean estimates (mean +/- SD) of half-life of elimination (t1/2beta) of 0.32 +/- 0.14 h, systemic clearance (Cl) of 0.74 +/- 0.12 L/kg x h, and volume of distribution at steady state (V(ss)) of 0.23 +/- 0.051 L/kg. In milk, ketoprofen was unmeasurable by the method employed (level of detection 25 ng/mL) for all samples.

Pharmacokinetic studies of flunixin meglumine and phenylbutazone in plasma, exudate and transudate in sheep

Flunixin meglumine (FM, 1.1 mg/kg) and phenylbutazone (PBZ, 4.4 mg/kg) were administered intravenously (i.v.) as a single dose to eight sheep prepared with subcutaneous (s.c.) tissue-cages in which an acute inflammatory reaction was stimulated with carrageenan. Pharmacokinetics of FM, PBZ and its active metabolite oxyphenbutazone (OPBZ) in plasma, exudate and transudate were investigated. Plasma kinetics showed that FM had an elimination half-life (t1/2beta) of 2.48 +/- 0.12 h and an area under the concentration - time curve (AUC) of 30.61 +/- 3.41 Lg/mL x h. Elimination of PBZ from plasma was slow (t1/2beta = 17.92 +/- 1.74 h, AUC = 968.04 +/- microg/mL x h). Both FM and PBZ distributed well into exudate and transudate although penetration was slow, indicated by maximal drug concentration (Cmax) for FM of 1.82 +/- 0.22 microg/mL at 5.50 +/- 0.73 h (exudate) and 1.58 +/- 0.30 microg/mL at 8.00 h (transudate), and Cmax for PBZ of 22.32 +/- 1.29 microg/mL at 9.50 +/- 0.73 h (exudate) and 22.07 +/- 1.57 microg/mL at 11.50 +/- 1.92 h (transudate), and a high mean tissue-cage fluids:plasma AUClast ratio obtained in the FM and PBZ groups (80-98%). These values are higher than previous reports in horses and calves using the same or higher dose rates. Elimination of FM and PBZ from exudate and transudate was slower than from plasma. Consequently the drug concentrations in plasma were initially higher and subsequently lower than in exudate and transudate.

Advances in the therapy for mastitis

Methods to enhance mammary resistance to bacterial infection and to reduce the effects of existing infections without the use of antimicrobial agents are becoming more attractive, primarily because of increasing pressure from consumers and regulatory agencies to decrease the risk of drug residues in milk. Because of the difficulty in obtaining satisfactory results with existing drug formulations, new approaches in the treatment of mastitis should emphasize better understanding of mammary gland pharmacokinetics, ameliorating the pathologic effects of infection, and enhancing natural defenses. Efficacy studies should emphasize milk production and long-term survival of cows to allow economic evaluations.

The pharmacokinetics of flunixin meglumine in the sheep

Flunixin meglumine was administered intravenously and intramuscularly in sheep and the pharmacokinetics of the drug studied. Plasma concentrations of flunixin were measured by high performance liquid chromatography. The decline in plasma flunixin concentration with time was best fitted by a triexponential equation. The pharmacokinetics following intravenous administration of 1.0 mg/kg indicate that flunixin has a rapid distribution half-life (t1/2 pi = 2.3 min), a slow body clearance rate (Clb = 0.6 ml/kg/min) and an elimination half-life of 229 min. Similarly, at 2.0 mg/kg, flunixin is rapidly distributed from the plasma, t1/2 pi = 2.7 min, has a slow body clearance rate (Clb = 0.7 ml/kg/min) and an elimination half-life of 205 min. Following intramuscular injection flunixin is rapidly and well absorbed from the injection site. It had a mean maximum concentration (Cmax) of > or = 5.9 micrograms/ml when administered at a dose rate of 1.1 mg/kg, and a relative bioavailability of 70%. Plasma concentrations increase proportionally to dose over the range 1.1 mg/kg-2.2 mg/kg when administered by the intramuscular route.