Energy and protein requirements for growth of Holstein × Gyr heifers

There is little information regarding the nutritional requirements for dairy heifers, leading the majority of nutrient requirement systems to consider dairy heifers to be similar to beef heifers. Therefore, we evaluated the muscle protein metabolism and physical and chemical body composition of growing Holstein × Gyr heifers and estimated the energy and protein requirements. We performed a comparative slaughter experiment with 20 Holstein × Gyr heifers at an initial body weight of 218 ± 36.5 kg and an average age of 12 ± 1.0 months. Four heifers were designated as the reference group, and the 16 remaining heifers were fed ad libitum . The 16 heifers were distributed using a completely randomized design in a 2 × 2 factorial arrangement with two roughages (corn silage or sugarcane) and two concentrate levels (30 or 50%) for 112 days. Greater (p  <  0.05) values for fractional rates of muscle protein synthesis, degradation and accretion were observed for heifers that were fed 50% concentrate. The following equations were obtained to estimate the net energy for gain (NE _g) and net protein for gain (NP _g): NE _g (Mcal/day) = 0.0685 × EBW ^0.75 × EBWG ^1.095 and NP _g (g/day) = 203.8 × EBWG  ? 14.80 × RE , respectively, in which EBW is the empty body weight, EBWG is the empty body weight gain and RE is the retained energy. We concluded that increased rates of protein turnover are achieved when a greater quality diet is provided. In the future, these results can be used to calculate the nutritional requirements for growth of Holstein × Gyr heifers after equation validation rather than using the recommendations provided by other systems, which use values developed from beef heifers, to determine the nutritional requirements of dairy cattle.     

A prediction equation for enteric methane emission from dairy cows for use in NorFor

Abstract

A data-set with 47 treatment means (N = 211) was compiled from research institutions in Denmark, Norway, and Sweden in order to develop a prediction equation for enteric methane (CH₄) emissions from dairy cows. The aim was to implement the equation in the Nordic feed evaluation system NorFor. The equation should therefore be based on input variables available in NorFor. The best equation to predict CH₄ (MJ/d) was based on dry matter intake (DMI, kg/d), and content of (g/kg DM) fatty acids (FA), crude protein (CP), and neutral detergent fiber (NDF). The equation was CH₄ = 1.36 (±0.10) × DMI – 0.125 (±0.039) × FA – 0.02 (±0.012) × CP + 0.017 (±0.005) × NDF (RMSE = 3.00 MJ CH₄/d; CV = 13.8%; R² = 0.77), where RMSE is the root mean square error and CV is the coefficient of variation. However, CP was on the borderline of being significant and did not quantitatively explain much variation in CH₄ emission. Based on the present research, we concluded, therefore, that the equation CH₄ = 1.23 (±0.08) × DMI – 0.145 (±0.039) × FA + 0.012 (±0.005) × NDF (RMSE = 3.10 MJ CH₄/d; CV = 14.3%; R² = 0.75) is most suited for being implemented in NorFor. However, the ability of the proposed equation to predict enteric methane emissions is uncertain until evaluated on an independent data-set.     

Pharmacokinetics of cefquinome in red‐eared slider turtles (Trachemys scripta elegans) after single intravenous and intramuscular injections

The purpose of this study was to evaluate the pharmacokinetics of cefquinome (CFQ ) following single intravenous (IV ) or intramuscular (IM ) injections of 2 mg/kg body weight in red‐eared slider turtles. Plasma concentrations of CFQ were determined by high‐performance liquid chromatography and analyzed using noncompartmental methods. The pharmacokinetic parameters following IV injection were as follows: elimination half‐life (t _1/2λz) 21.73 ± 4.95 hr, volume of distribution at steady‐state (V _dss) 0.37 ± 0.11 L/kg, area under the plasma concentration–time curve (AUC _0–∞) 163 ± 32 μg hr^?1 ml^?1, and total body clearance (Cl_T) 12.66 ± 2.51 ml hr^?1 kg^?1. The pharmacokinetic parameters after IM injection were as follows: peak plasma concentration (C _max) 3.94 ± 0.84 μg/ml, time to peak concentration (T _max) 3 hr, t _1/2λz 26.90 ± 4.33 hr, and AUC _0–∞ 145 ± 48 μg hr^?1 ml^?1. The bioavailability after IM injection was 88%. Data suggest that CFQ has a favorable pharmacokinetic profile with a long half‐life and a high bioavailability in red‐eared slider turtles. Further studies are needed to establish a multiple dosage regimen and evaluate clinical efficacy.     

Pharmacokinetics of intravenous gentamicin in healthy young‐adult compared to aged alpacas

The study objective was to evaluate the effects of age on aminoglycoside pharmacokinetics in eight young‐adult (<4 years) and eight aged (≥14 years) healthy alpacas, receiving a single 6.6 mg/kg intravenous gentamicin injection. Heparinized plasma samples were obtained at designated time points following drug administration and frozen at ?80°C until assayed by a validated immunoassay (QMS ^®). Compartmental and noncompartmental analyses of gentamicin plasma concentrations versus time were performed using WinNonlin (v6.4) software. Baseline physical and hematological parameters were not significantly different between young and old animals with the exception of sex. Data were best fitted to a two‐compartment pharmacokinetic model. The peak drug concentration at 30 min after dosing (23.8 ± 2.1 vs. 26.1 ± 2 μg/ml, p = .043 ) and area under the curve (70.4 ± 10.5 vs. 90.4 ± 17.6 μg hr/ml, p = .015 ) were significantly lower in young‐adult compared to aged alpacas. Accordingly, young alpacas had a significantly greater systemic clearance than older animals (95.5 ± 14.4 and 75.6 ± 16.1 ml hr^?1 kg^?1; p = .018 ), respectively). In conclusion, a single 6.6 mg/kg intravenous gentamicin injection achieves target blood concentrations of >10 times the MIC of gentamicin‐susceptible pathogens with MIC levels ≤2 μg/ml, in both young‐adult and geriatric alpacas. However, the observed reduction in gentamicin clearance in aged alpacas may increase their risk for gentamicin‐related adverse drug reactions.     

Assessment of the usage of biodegradable polymeric matrix in vaginal devices to sustain progesterone release in cows

The usage of timed artificial insemination (TAI) at a low cost leading to better reproductive rates has been the aim of several research groups in the field. Usually during TAI protocols, sustained progesterone (P₄) release devices are employed. Most devices are constituted of a nylon skeleton covered with a silicon layer with P₄. A device based on biopolymers was developed in order to reduce costs and decrease its environmental impact. In this study, we compared the kinetics of sustained progesterone release among devices manufactured with a polymeric blend made of polyhydroxybutyrate‐valerate (PHBV) and poly‐ε‐caprolactone (PCL) (DISP) which were compared with DIB® (Internal Bovine Device) used as the control. In the in vitro and in vivo progesterone release tests, two types of biopolymer‐based devices with a superficial area of 147 cm² were used: DISP8 (46% PHBV, 46% PCL and 8% P₄; n  = 4), DISP10 (45% PHBV, 45% PCL, 10% P₄; n  = 4) and DIB® (1 g P₄, 120 cm² area; n  = 3). The in vitro tests were carried out according to USP XXIII specifications and were performed in a dissolutor sink using an alcohol/water mixture (60/40 v/v) as a release media and samples were collected at 2 min, 2, 4, 8, 12, 24, 48, 60, 72, 84 and 96 h. P₄ concentrations were measured through spectrophotometry in a 244 nm long wave. Three to 3 comparisons of angular coefficients of the straight lines obtained by regression analysis of accumulated P₄ concentrations as a function of square root of time were carried out. Furthermore, the diffusion coefficient values of P₄ were also determined for DISP8 and DISP10. The results showed that the concentrations of P₄ were higher in the DISP10 (774.63 ± 45.26 μg/cm²/t^1/2) compared to DISP8 (566.17 ± 3.68 μg/cm²/t^1/2) (P  < 0.05). However, both DISP10 and DISP8 P₄ concentrations did not differ from DIB® (677.39 ± 16.13 μg/cm²/t^1/2). For the analysis of released quantities per day of the in vitro test, four periods were considered: 0–24, 24–48, 48–72 and 72–96 h. In the first 24 h, DISP8 released significantly less P₄ than DISP10 or DIB®, which did not differ among them. Between 24 and 48 h, DISP10 released significantly more P₄ than DIB®. DISP8 released an intermediate P₄ amount and did not differ significantly from DIB® or DISP10. Between 48 and 72 h, P₄ quantity released by DISP10 was significant higher (P  < 0.01) than that of DIB® and DISP8, which did not differ among themselves. Between 72 and 96 h, DISP10 released significantly more P₄ than DIB®, and DISP8 released an intermediate amount which did not differ from DIB® or DISP10 (P  < 0.01). There was interaction between treatment and time (P  = 0.0024). The diffusion coefficient values were: 1.36 × 10^?8 (cm²/s) for DISP10 and 1.12 × 10^?8 (cm²/s) for DISP8. For the in vivo test, ovariectomized crossbred cows received DIB® (n  = 4) or DISP8 (n  = 8) in an alternate design with a non‐balanced sequence (cross‐over) added of measures repeated in time referring to 16 days of blood samples collection. Samples were analyzed through radioimmunoassay in solid phase using the commercial kit of DPC (Diagnostics Products Corporation). Plasma concentrations of P₄ peaked at 4 h after the placement of the device, this being the only time in which plasma P₄ concentrations differed between DIB® (11.45 ± 1.96) compared with DISP8 (9.23 ± 1.15 ng/mL) (P  = 0.027). On day 8, plasma P₄ concentrations were similar for DIB® (2.44 ± 0.09) and DISP8 (1.89 ± 0.13 ng/mL) (P  = 0.58) showing that both devices were able to keep P₄ concentrations above 1 ng/mL in the plasma of the cow during the 16 day in vivo test. In conclusion, devices manufactured with the blend of PHBV/PCL biopolymers can sustain the release of P₄ in a similar manner as silicon.     

Pharmacokinetic–pharmacodynamic relationship of marbofloxacin for Escherichia coli and Pasturella multocida following repeated intramuscular administration in goats

The pharmacokinetics (PK) and pharmacodynamics (PD) of marbofloxacin (MBF) were determined in six healthy female goats of age 1.00–1.25 years after repeated administration of MBF. The MBF was administered intramuscularly (IM) at 2 mg kg^?1 day^?1 for 5 days. Plasma concentrations of MBF were determined by high‐performance liquid chromatography, and PK parameters were obtained using noncompartmental analysis. The MBF concentrations peaked at 1 hr, and peak concentration (C_max) was 1.760 µg/ml on day 1 and 1.817 µg/ml on day 5. Repeated dosing of MBF caused no significant change in PK parameters except area under curve (AUC) between day 1 (AUC_0–∞D1 = 7.67 ± 0.719 µg × hr/ml) and day 5 (AUC_0‐∞D5 = 8.70 ± 0.857 µg × hr/ml). A slight difference in mean residence time between 1st and 5th day of administration and accumulation index (AI = 1.13 ± 0.017) suggested lack of drug accumulation following repeated IM administration up to 5 days. Minimum inhibitory concentration (MIC) demonstrated that Escherichia coli (MIC = 0.04 µg/ml) and Pasturella multocida (MIC = 0.05 µg/ml) were highly sensitive to MBF. Time‐kill kinetics demonstrated rapid and concentration‐dependent activity of MBF against these pathogens. PK/PD integration of data for E. coli and P. multocida, using efficacy indices: C_max/MIC and AUC_0–24hr/MIC, suggested that IM administration of MBF at a dose of 2 mg kg^?1 day^?1 is appropriate to treat infections caused by E. coli. However, a dose of 5 mg kg^?1 day^?1 is recommended to treat pneumonia caused by P. multocida in goats. The study indicated that MBF can be used repeatedly at dosage of 2 mg/kg in goats without risk of drug accumulation up to 5 days.     

Development of prediction equation for methane‐related traits in beef cattle under high concentrate diets

The objective of this study was to develop a prediction equation for methane‐related traits in beef cattle and evaluate this equation using datasets with different cattle breeds and roughage rates. Enteric methane emission (CH₄, l/day) was measured using open‐circuit respiration chambers. Dry matter intake (DMI, kg/day), body weight (BW, kg), daily gain (DG, kg), total digestible nutrients (TDN, %DMI), and roughage rate (Rrate, %) were used as independent variables, and methane‐related traits—CH₄, CH₄ per DMI (CH₄/DMI, l/kg), and methane conversion factor (MCF, %)—were used as dependent variables. The best‐fit equations to predict methane‐related traits using a total of 76 records were CH₄ = –676.7 + 0.04194 × BW + 29.88 × DMI + 7.883 × TDN + 4.367 × Rrate, CH₄/DMI = –52.24 – 1.193 × 10^–3 × BW – 5.905 × DG + 1.077 × TDN + 0.5008 × Rrate, and MCF = –11.43 – 5.308 × 10^–4 × BW – 1.223 × DG + 0.2336 × TDN + 0.1157 × Rrate. The predictive ability of the developed equations differed between roughage rates but not between breeds. For CH₄, the predictive ability of the developed equations was better compared with previously reported equations in the low roughage rate dataset, but not in the high roughage rate dataset. Our results suggest that the developed equations of methane‐related traits can be applied in beef cattle fed with low roughage diets.     

Pharmacokinetics and pharmacodynamics of alfaxalone after a single intramuscular or intravascular injection in mallard ducks (Anas platyrhynchos)

Pharmacokinetics and pharmacodynamics of alfaxalone was performed in mallard ducks (Anas platyrhynchos) after single bolus injections of 10 mg/kg administered intramuscularly (IM; n = 10) or intravenously (IV; n = 10), in a randomized cross‐over design with a washout period between doses. Mean (±SD) C_max following IM injection was 1.6 (±0.8) µg/ml with T_max at 15.0 (±10.5) min. Area under the curve (AUC) was 84.66 and 104.58 min*mg/ml following IV and IM administration, respectively. Volume of distribution (V_D) after IV dose was 3.0 L/kg. The mean plasma clearance after 10 mg/kg IV was 139.5 (±67.9) ml min^?1 kg^?1. Elimination half‐lives (mean [±SD]) were 15.0 and 16.1 (±3.0) min following IV and IM administration, respectively. Mean bioavailability at 10 mg/kg IM was 108.6%. None of the ducks achieved a sufficient anesthetic depth for invasive procedures, such as surgery, to be performed. Heart and respiratory rates measured after administration remained stable, but many ducks were hyperexcitable during recovery. Based on sedation levels and duration, alfaxalone administered at dosages of 10 mg/kg IV or IM in mallard ducks does not induce clinically acceptable anesthesia.     

Influence of ration composition on nutritive and digestive variables in captive giraffes (Giraffa camelopardalis) indicating the appropriateness of feeding practice

The nutrition of captive giraffe (Giraffa camelopardalis ), a browsing ruminant, is challenging because browse availability is limited in zoos and rations need to be composed of compensatory feeds. In this study, ration composition for giraffes in 12 German zoos was documented and linked to animal variables that indicate suitability of nutrition. Rations differed in proportion of ration items and chemical composition resulting in various grades of accordance with feeding recommendations. An estimated daily metabolisable energy (ME ) intake (MEI ; mean ± SD ) of 0.61 MJ ME/kg^0.75 body weight (BW ; ±0.1) was sufficient to cover estimated energy requirements. Daily dry matter (DM ) intake (DMI ) was 61 g DM/kg^0.75 BW (±10) and correlated negatively to dietary ME content (p  = .009; r  = ?.596). Apparently, feed intake was regulated by energetic satiety and not by physical properties of forage. A negative correlation between produce proportion and DMI (p  = .002; r  = ?.676) led to the assumption of a low ruminal pH in giraffes fed high proportions of produce. Increasing dietary forage proportions led to an increasing duration of feed intake (p  = .045; r  = .477) and decreasing occurrence of oral stereotypies (p  = .047; r  = ?.474). The weighted average faecal particle size was larger than reported for free‐ranging giraffes, but no relation to ration characteristics among the facilities existed. The abrasiveness of rations was not excessive, as contents of silicate in faeces were similar to values from the wild. Body condition was generally acceptable, but there was no evident relation to ration characteristics. The capacity to self‐regulate DM and ME intakes with lucerne hay may work at higher forage proportions than often assumed for captive giraffes. Rations with less energetic density can result in a greater DMI , including maximisation of forage intake and reduction of oral stereotypies.     

Bayesian population pharmacokinetic modeling of florfenicol in pigs after intravenous and intramuscular administration

Bayesian population pharmacokinetic models of florfenicol in healthy pigs were developed based on retrospective data in pigs either via intravenous (i.v.) or intramuscular (i.m.) administration. Following i.v. administration, the disposition of florfenicol was best described by a two‐compartment open model with the typical values of half‐life at α phase (t _1/2α), half‐life at β phase (t _1/2β), total body clearance (Cl), and volume of distribution (V _d) were 0.132 ± 0.0289, 2.78 ± 0.166 hr, 0.215 ± 0.0102, and 0.841 ± 0.0289 L kg^?1, respectively. The disposition of florfenicol after i.m. administration was best described by a one‐compartment open model. The typical values of maximum concentration of drug in serum (C _max), elimination half‐life (t _1/2Kel), Cl, and Volume (V ) were 5.52 ± 0.605 μg/ml, 9.96 ± 1.12 hr, 0.228 ± 0.0154 L hr^?1 kg^?1, and 3.28 ± 0.402 L/kg, respectively. The between‐subject variabilities of all the parameters after i.m. administration were between 25.1%–92.1%. Florfenicol was well absorbed (94.1%) after i.m. administration. According to Monte Carlo simulation, 8.5 and 6 mg/kg were adequate to exert 90% bactericidal effect against Actinobacillus pleuropneumoniae after i.v. and i.m. administration.     

Methane emission of Santa Inês sheep fed cottonseed by-products containing different levels of gossypol

The aim of this study was to evaluate the methane (CH₄) emission of Santa Inês sheep fed cottonseed by-products, verifying if the gossypol content of these feedstuffs affects CH₄ emission. Twelve late-lactating Santa Inês sheep (44.8?±?7.5 kg body weight (BW)) were allocated in metabolic cages for an experimental period of 19 days, 14 days for adaptation and 5 days for measuring CH₄ emission and dry matter intake (DMI). The animals were divided into four treatments, established in accordance with the cottonseed by-product used in concentrate formulation: Control (CON - no cottonseed by-product), Whole cottonseed (WCS), Cottonseed cake (CSC), and Cottonseed meal (CSM). The free gossypol level of the concentrates were 0, 1,276, 350, and 190 ppm for CON, WCS, CSC, and CSM, respectively. Also, the animals received Cynodon dactylon cv. Coast Cross hay, water, and mineral salt ad libitum. The ether extract content of the diets was balanced between treatments by including soybean oil in concentrates. The technique used to measure the CH₄ emission was the sulfur hexafluoride (SF₆) tracer technique, and the gas samples collected were quantified by analysis in gas chromatography system. The CH₄ emission was evaluated considering the daily emission (g CH₄/day); DMI (g CH₄/kg DMI); and BW (g CH₄/kg BW). No statistical difference was found (P?>?0.05) between treatments for DMI and CH₄ parameters. In the regression analysis, no significant relation (P?>?0.05) between gossypol content and CH₄ emission was observed. These results suggest that gossypol does not affect rumen methanogenesis.     

Administration of exogenous hormones in ovulatory and embryonic response in Pelibuey sheep

The objective of this study was to evaluate the effect of two sources of commercial porcine pituitary‐derived follicle‐stimulating hormone (pFSH) and pFSH—porcine Luteinizing Hormone (pLH), including equine chorionic gonadotropin (eCG), in ovulatory and embryonic response in Pelibuey sheep. Twenty‐four Pelibuey sheep were used and were assigned randomly to four treatments (n = 6): (T1; 200 mg pFSH‐Folltropin^®); (T2; 200 mg pFSH + 300 UI eCG‐Folligon^®); (T3; 250 UI pFSH/pLH‐Pluset^®) and (T4; 250 UI pFSH/pLH + 300 UI eCG). The interval of hours from withdrawal of the device to the beginning of oestrus (BO) was lower (p < .05) in sheep treated with eCG (T2 = 8.0 ± 1.4 and T4 = 10.0 ± 2.8) than in those without eCG (T1 = 12.6 ± 0.6 and T3 = 20.6 ± 2.4). The ovulatory rate (OR) was higher (p < .05) in T1 = 15.5 ± 2.8 and T2 = 15.6 ± 1.4, compared to T3 = 8.1 ± 3.2 and T4 = 11.8 ± 2.8; a significant difference was not shown between them (T1 vs. T2 and T3 vs. T4) when including eCG. The number of non‐fertilized oocytes (NFO) was lower (p ? .05) in T1 = 0.8 ± 0.4 and T3 = 1.8 ± 1.8, compared to those that included eCG (T2 = 6.3 ± 2.4 and T4 = 2.1 ± 1.2). The number of transferable embryos (TE) was higher (p < .05) when FSH was applied (T1 = 5.8 ± 1.1), compared with (T2 = 2.6 ± 1.1, T3 = 2.3 ± 1.4 and T4 = 2.8 ± 1.5). The commercial treatments (pFSH or pFSH‐pLH) in combination with eCG did not improve OR, NFO and TE. However, the exclusive pFSH (Folltropin) treatment presented a higher OR, lower number of NFO and higher number of TE.     

Retracted: Determination of some blood and seminal plasma ions in the beluga,Huso huso (Linnaeus, 1758)

Blood and seminal plasma ionic parameters are essential for monitoring health status, detecting illnesses, fish stock conservation and development of artificial propagation methods via extender improvement. In this study, comparison of blood and seminal plasma ionic parameters in beluga, Huso huso (30–45 kg, 1–2 m, n = 10), was made. The results obtained show that Na⁺ (82.54 ± 5.46), Cl^‐ (15.95 ± 0.72) and K⁺ (3.57 ± 0.15) were predominant ions in the seminal plasma (as mm ). Blood ionic values (as mm ) were determined for Na⁺ (110.2 ± 1.26), K⁺ (3.77 ± 0.081), Cl^? (60.12 ± 1.5), Ca²⁺ (2.05 ± 0.35) and Mg²⁺ (1.9 ± 0.16). Results of the comparison between ionic parameters of seminal and blood plasma indicated that the concentrations of all parameters of blood plasma with the exception of K⁺ were significantly (p < 0.05) higher than those of seminal plasma.     

Disposition of levetiracetam in healthy adult horses

Nine horses received 20 mg/kg of intravenous (LEV_IV ); 30 mg/kg of intragastric, crushed immediate release (LEV_CIR ); and 30 mg/kg of intragastric, crushed extended release (LEV_CER ) levetiracetam, in a three‐way randomized crossover design. Crushed tablets were dissolved in water and administered by nasogastric tube. Serum samples were collected over 48 hr, and levetiracetam concentrations were determined by immunoassay. Mean ± SD peak concentrations for LEV_CIR and LEV_CER were 50.72 ± 10.60 and 53.58 ± 15.94 μg/ml, respectively. The y ‐intercept for IV administration was 64.54 ± 24.99 μg/ml. The terminal half‐life was 6.38 ± 1.97, 7.07 ± 1.93 and 6.22 ± 1.35 hr for LEV_CIR , LEV_{CER ,} and LEV_IV , respectively. Volume of distribution at steady‐state was 630 ± 73.4 ml/kg. Total body clearance after IV administration was 74.40 ± 19.20 ml kg^?1 hr^?1. Bioavailability was 96 ± 10, and 98 ± 13% for LEV_CIR and LEV_CER , respectively. A single dose of Levetiracetam (LEV ) was well tolerated. Based on this study, a recommended dosing regimen of intravenous or oral LEV of 32 mg/kg every 12 hr is likely to achieve and maintain plasma concentrations within the therapeutic range suggested for humans, with optimal kinetics throughout the dosing interval in healthy adult horses. Repeated dosing and pharmacodynamic studies are warranted.     

Pharmacokinetics and antinociceptive effects of the soluble epoxide hydrolase inhibitor t‐TUCB in horses with experimentally induced radiocarpal synovitis

This study determined the pharmacokinetics, antinociceptive, and anti‐inflammatory effects of the soluble epoxide hydrolase (sEH ) inhibitor t ‐TUCB (trans ‐4‐{4‐[3‐(4‐Trifluoromethoxy‐phenyl)‐ureido]‐cyclohexyloxy}‐benzoic acid) in horses with lipopolysaccharide (LPS )‐induced radiocarpal synovitis. A total of seven adult healthy mares (n  = 4–6/treatment) were administered 3 μg LPS into one radiocarpal joint and t ‐TUCB intravenously (i.v.) at 0 (control), 0.03, 0.1, 0.3, and 1 mg/kg in a blinded, randomized, crossover design with at least 3 weeks washout between. Two investigators independently assigned pain scores (at rest, walk and trot) and lameness scores before and up to 48 hr after t ‐TUCB /LPS . Responses to touching the joint skin to assess tactile allodynia, plasma, and synovial fluid (SF ) t ‐TUCB concentrations were determined before and up to 48 hr after t ‐TUCB /LPS . Blood and SF were collected for clinical laboratory evaluations before and up to 48 hr after t ‐TUCB /LPS . Areas under the curves of pain and lameness scores were calculated and compared between control and treatments. Data were analyzed using repeated measures ANOVA with Dunnett or Bonferroni post‐test. p  < .05 was considered significant. Data are mean ± SEM . Compared to control, pain, lameness, and tactile allodynia were significantly lower with 1 mg/kg t ‐TUCB , but not the other doses. For 0.1, 0.3, and 1 mg/kg t ‐TUCB treatments, plasma terminal half‐lives were 13 ± 3, 13 ± 0.5, and 24 ± 5 hr, and clearances were 68 ± 15, 48 ± 5, and 14 ± 1 ml hr^?1 kg^?1. The 1 mg/kg t ‐TUCB reached the SF at high concentrations. There were no important anti‐inflammatory effects. In conclusion, sEH inhibition with t ‐TUCB may provide analgesia in horses with inflammatory joint pain.     

Tropical tanniniferous legumes used as an option to mitigate sheep enteric methane emission

This study presents the first results from Brazil using SF₆ tracer technique adapted from cattle to evaluate the capability of condensed tannin (CT) present in three tropical legume forages, Leucaena leucocephala (LEU), Styzolobium aterrimum (STA), and Mimosa caesalpiniaefolia Benth (MIM) to reduce enteric CH₄ production in Santa Inês sheep. Twelve male lambs [27.88?±?2.85 kg body weight (BW)] were allocated in individual metabolic cages for 20-day adaptation followed by 6 days for measuring dry matter intake (DMI) and CH₄ emission. All lambs received water, mineral supplement, and Cynodon dactylon v. coast-cross hay ad libitum. The treatments consisted of soybean meal (710 g/kg) and ground corn (290 g/kg) [control (CON)]; soybean meal (150 g/kg), ground corn (30 g/kg), and Leucaena hay (820 g/kg) (LEU); soybean meal (160 g/kg), ground corn (150 g/kg), and Mucuna hay (690 g/kg) (STA); and soybean meal (280 g/kg), ground corn (190 g/kg), and Mimosa hay (530 g/kg) (MIM); all calculated to provide 40 g/kg CT (except for CON). DMI (in grams of DMI per kilogram BW per day) was lower for LEU (22.0) than CON (29.3), STA (31.2), and MIM (31.6). The LEU group showed emission of 7.8 g CH₄/day, significantly lower than CON (10.5 g CH₄/day), STA (10.4 g CH₄/day), and MIM (11.3 g CH₄/day). However, when the CH₄ emission per DMI was considered, there were no significant differences among treatments (0.37, 0.36, 0.33, and 0.35 g CH₄/g DMI/kg BW/day, respectively, for CON, LEU, STA, and MIM). The sheep receiving STA had shown a tendency (p?=?0.15) to reduce methane emission when compared to the CON group. Therefore, it is suggested that tropical tanniniferous legumes may have potential to reduce CH₄ emission in sheep, but more research is warranted to confirm these results.     

Pharmacokinetics of posaconazole in koalas (Phascolarctos cinereus) after intravenous and oral administration

The pharmacokinetic profile of posaconazole in clinically normal koalas (n = 8) was investigated. Single doses of posaconazole were administered intravenously (i.v.; 3 mg/kg; n = 2) or orally (p.o.; 6 mg/kg; n = 6) with serial plasma samples collected over 24 and 36 hr, respectively. Plasma concentrations of posaconazole were quantified by validated high‐performance liquid chromatography. A noncompartmental pharmacokinetic analysis of data was performed. Following i.v. administration, estimates of the median (range) of plasma clearance (CL) and steady‐state volume of distribution (V_ss) were 0.15 (0.13–0.18) L hr^?1 kg^?1 and 1.23 (0.93–1.53) L/kg, respectively. The median (range) elimination half‐life (t_1/2) after i.v. and p.o. administration was 7.90 (7.62–8.18) and 12.79 (11.22–16.24) hr, respectively. Oral bioavailability varied from 0.43 to 0.99 (median: 0.66). Following oral administration, maximum plasma concentration (C_max; median: 0.72, range: 0.55–0.93 μg/ml) was achieved in 8 (range 6–12) hr. The in vitro plasma protein binding of posaconazole incubated at 37°C was 99.25 ± 0.29%. Consideration of posaconazole pharmacokinetic/pharmacodynamic (PK/PD) targets for some yeasts such as disseminated candidiasis suggests that posaconazole could be an efficacious treatment for cryptococcosis in koalas.     

P‐glycoprotein in sheep liver and small intestine: gene expression and transport efflux activity

The role of the transporter P‐glycoprotein (P‐gp) in the disposition kinetics of different drugs therapeutically used in veterinary medicine has been demonstrated. Considering the anatomo‐physiological features of the ruminant species, the constitutive expression of P‐gp (ABCB1) along the sheep gastrointestinal tract was studied. Additionally, the effect of repeated dexamethasone (DEX) administrations on the ABCB1 gene expression in the liver and small intestine was also assessed. The ABCB1 mRNA expression was determined by real‐time quantitative PCR. P‐gp activity was evaluated in diffusion chambers to determine the efflux of rhodamine 123 (Rho 123) in the ileum from experimental sheep. The constitutive ABCB1 expression was 65‐fold higher in the liver than in the intestine (ileum). The highest ABCB1 mRNA expression along the small intestine was observed in the ileum (between 6‐ and 120‐fold higher). The treatment with DEX did not elicit a significant effect on the P‐gp gene expression levels in any of the investigated gastrointestinal tissues. Consistently, no significant differences were observed in the intestinal secretion of Rho 123, between untreated control (P_eff S‐M = 3.99 × 10^?6 ± 2.07 × 10^?6) and DEX‐treated animals (P_eff S‐M = 6.00 × 10^?6 ± 2.5 × 10^?6). The understanding of the efflux transporters expression and activity along the digestive tract may help to elucidate clinical implications emerging from drug interactions in livestock.     

Pharmacokinetics of orbifloxacin in crucian carp (Carassius auratus) after intravenous and intramuscular administration

The pharmacokinetics of orbifloxacin was studied after a single dose (7.5 mg/kg) of intravenous or intramuscular administration to crucian carp (Carassius auratus ) reared in freshwater at 25°C. Plasma samples were collected from six fish per sampling point. Orbifloxacin concentrations were determined by high‐performance liquid chromatography with a 0.02 μg/ml limit of detection, then were subjected to noncompartmental analysis. After intravenous injection, initial concentration of 5.83 μg/ml, apparent elimination rate constant (λ_z) of 0.039 hr^?1, apparent elimination half‐life (T_1/2λz) of 17.90 hr, systemic total body clearance (Cl) of 75.47 ml hr^?1 kg^?1, volume of distribution (Vz) of 1,948.76 ml/kg, and volume of distribution at steady‐state (Vss) of 1,863.97 ml/kg were determined, respectively. While after intramuscular administration, the λ_z, T _1/2λz, mean absorption time (MAT ), absorption half‐life (T _1/2ka), and bioavailability were determined as 0.027 hr^?1, 25.69, 10.26, 7.11 hr, and 96.46%, respectively, while the peak concentration was observed as 3.11 ± 0.06 μg/ml at 2.0 hr. It was shown that orbifloxacin was completely but relatively slowly absorbed, extensively distributed, and slowly eliminated in crucian carp, and an orbifloxacin dosage of 10 mg/kg administered intravenously or intramuscularly would be expected to successfully treat crucian carp infected by strains with MIC values ≤0.5 μg/ml.     

Study of Sperm Concentration,Seminal Plasma Composition and their Physiological Correlation in the Persian Sturgeon,Acipenser persicus

The objectives of the present study were to determine ionic and organic composition of seminal plasma, sperm concentration and their relationships in the Persian sturgeon (Acipenser persicus). In this regard, ionic content (Na⁺, K⁺, Cl^?, Ca²⁺ and Mg²⁺) and organic content (total protein, glucose, cholesterol and triglyceride) along with sperm concentration were measured in 17 specimens of the Persian sturgeon. The seminal plasma contained 59.53 ± 2.56 mm /l sodium, 9.1 ± 1.42 mm chloride, 4.72 ± 0.3 mm potassium, 1.45 ± 0.075 mm calcium and 0.7 ± 0.072 mm magnesium. The following organic contents were found: total protein 0.11 ± 0.02 g/dl, glucose 22.18 ± 4.16 mg/dl, cholesterol 6.67 ± 1.04 mg/dl and triglyceride 15.2 ± 0.65 mg/dl. The mean sperm concentration was estimated to be 1.6 ± 0.12 (×10⁹ sperm/ml). A significant relationship was found between sperm concentration and K⁺ of seminal plasma (r = 0.533, p < 0.05). Significant correlations were observed between ionic contents: Na⁺ vs Cl^? (r = ?0.854, p < 0.01) and Mg²⁺ vs K⁺ (?0.583, p < 0.05). Also, level of triglyceride was negatively correlated with Mg²⁺ (r = ?0.503, p < 0.05). Presented data could be considered as a complementary study for developing special extenders and protectant solutions for improving artificial fertilization in this valuable species.