Inclusion of dicopper oxide instead of copper sulfate in diets for growing–finishing pigs results in greater final body weight and bone mineralization,but reduced accumulation of copper in the liver

An experiment was conducted to test the hypothesis that inclusion of Cu oxide (Cu₂O) in diets for growing–finishing pigs improves body weight (BW) and bone mineralization, and reduces accumulation of Cu in the liver compared with pigs fed diets containing Cu sulfate (CuSO₄). Two hundred growing pigs (initial BW: 11.5 ± 0.98 kg) were allotted to a randomized complete block design with 2 blocks of 100 pigs, 5 dietary treatments, 5 pigs per pen, and a total of 8 pens per treatment. Treatments included the negative control (NC) diet that contained 20 mg Cu/kg, and 4 diets in which 125 or 250 mg Cu/kg from CuSO₄ or Cu₂O were added to the NC diet. The experiment was divided into 4 phases and concluded when pigs reached market weight. Pig weights were recorded on day 1 and at the end of each phase and feed provisions were recorded throughout the experiment. On the last day of phases 1 and 4, 1 pig per pen was sacrificed to obtain samples of liver and spleen tissue, and the right metacarpal was collected. Results indicated that pigs fed diets containing 250 mg Cu/kg from CuSO₄ had greater BW at the end of phases 1 and 2 than pigs fed NC diets. Pigs fed diets containing 250 mg Cu/kg from Cu₂O had greater (P < 0.05) BW at the end of phases 1, 2, 3, and 4 compared with pigs fed NC diets, and these pigs also had greater BW at the end of phases 3 and 4 than pigs fed all other diets. Pigs fed the diets with 250 mg Cu/kg tended to have greater (P < 0.10) feed intake than pigs fed the NC diet at the end of phase 2, and for the overall experimental period, pigs fed diets containing 250 mg Cu/kg from Cu₂O had greater (P < 0.05) feed intake than pigs on all other treatments. However, no differences in gain:feed ratio were observed among treatments. Copper accumulation in liver and spleen increased with Cu dose, but at the end of phase 1, pigs fed 250 mg Cu/kg from CuSO₄ had greater (P < 0.05) Cu concentration in liver and spleen than pigs fed 250 mg Cu/kg from Cu₂O. Pigs fed diets containing 250 mg Cu/kg from Cu₂O had greater (P < 0.05) quantities of bone ash and greater (P < 0.05) concentrations of Ca, P, and Cu in bone ash than pigs fed NC diets or the 2 diets containing CuSO₄, but Zn concentration in bone ash was less (P < 0.05) in pigs fed diets containing 250 mg Cu/kg from Cu₂O. To conclude, supplementing diets for growing pigs with Cu₂O improves growth performance and bone mineralization with less Cu accumulation in liver compared with pigs fed diets containing CuSO₄.     

The anesthetic interaction of propofol and sevoflurane on the minimum alveolar concentration preventing motor movement (MACNM) in dogs

The objective of this study was to determine the effects of propofol on the minimum alveolar concentration of sevoflurane needed to prevent motor movement (MAC_NM) in dogs subjected to a noxious stimulus using randomized crossover design. Six, healthy, adult beagles (9.2 ± 1.3 kg) were used. Dogs were anesthetized with sevoflurane on 3 occasions, at weekly intervals, and baseline MAC_NM (MAC_NM-B) was determined on each occasion. Propofol treatments were administered as loading dose (LD) and constant rate infusion (CRI) as follows: Treatment 1 (T1) was 2 mg/kg body weight (BW) and 4.5 mg/kg BW per hour; T2 was 4 mg/kg BW and 9 mg/kg BW per hour; T3 was 8 mg/kg BW and 18 mg/kg BW per hour, respectively. Treatment MAC_NM (MAC_NM-T) determination was initiated 60 min after the start of the CRI. Two venous blood samples were collected and combined at each MAC_NM-T determination for measurement of blood propofol concentration using high-performance liquid chromatography method (HPLC). Data were analyzed using a mixed-model ANOVA and are presented as least square means (LSM) ± standard error of means (SEM).Propofol infusions in the range of 4.5 to 18 mg/kg BW per hour resulted in mean blood concentrations between 1.3 and 4.4 μg/mL, and decreased (P < 0.05) sevoflurane MAC_NM in a concentration-dependent manner. The percentage decrease in MAC_NM was 20.5%, 43.0%, and 68.3%, with corresponding blood propofol concentrations of 1.3 ± 0.3 μg/mL, 2.5 ± 0.3 μg/mL, and 4.4 ± 0.3 μg/mL, for T1, T2, and T3, respectively. Venous blood propofol concentrations were strongly correlated (r = 0.855, P < 0.0001) with the decrease in MAC_NM. In dogs, propofol decreased the sevoflurane MAC_NM in a concentration-dependent manner.     

Pharmacokinetics and Effects of Alkalization During Oral and Intravenous Administration of Naproxen in Horses

The use of suitable therapeutic protocols is particularly important when extra-label drugs are used or when physiological parameters are modified, as in the case of the administration of alkaline substances to racehorses. The pharmacokinetics of naproxen (NAP), after both intravenous (iv) and oral administration of 10 mg/kg body weight (BW), was investigated in horses under normal metabolic conditions and in horses whose conditions were modified by the iv administration of 250 mg/kg BW of sodium bicarbonate (NaHCO₃). The hypothesis that blood and consequent urinary alkalization could modify NAP pharmacokinetics was evaluated. Drug quantification was performed on serum and urine using High Performance Liquid Chromatography (HPLC) with ultraviolet-visible detection. Results were also integrated with cycloxygenase (COX)-inhibition published data to suggest an appropriate schedule for NAP dosage in horses. After iv administration, NAP was rapidly distributed (t_1/2α: 0.71 ± 0.43 iv NaHCO₃ and 0.55 ± 0.62 hours No NaHCO₃), whereas its elimination was quite slow (t_1/2β: 6.74 ± 0.41 hours), particularly in iv NaHCO₃ animals (t_1/2β: 8.95 ± 1.37 hours). After oral treatments, NAP was more rapidly absorbed and elimination was slower in iv NaHCO₃ animals (t_1/2λ_z: 17.50 ± 6.66 vs. 7.17 ± 0.91 hours). The oral bioavailability of NAP was approximately 87% and 77% in No NaHCO₃ and iv NaHCO₃, respectively. Urinary excretion of the drug as a parent compound was low. The alkalization procedure did not anticipate the elimination of the acidic drug as expected, but it also influenced the absorption of the drug that was administered orally. The dosage scheme of 10 mg/kg BW iv or orally seems to be appropriate to produce an anti-inflammatory effect for 12 to 24 hours.     

Pharmacokinetics of marbofloxacin after intravenous and intramuscular administration in Hanwoo,Korean native cattle

Pharmacokinetic (PK) parameters of marbofloxacin (MRFX) in Korean cattle, Hanwoo, were determined following its intravenous (i.v.) or intramuscular (i.m.) administration at a dose of 2 mg/kg. Area under the curve (AUC_{0–24 hr}), half-life (t_1/2) and total body clearance (CL_B) of i.v. MRFX were 6.87 hr∙µg/ml, 2.44 hr and 0.29 l/kg∙hr, respectively, and the corresponding values for i.m. administration of MRFX were 5.07 hr∙µg/ml, 2.44 hr and 0.39 l/kg∙hr. The suggested optimal doses of MRFX in Hanwoo cattle, calculated by integration of PK data obtained in the present study and previously reported minimum inhibitory concentration (MIC) for MRFX against susceptible (MIC ≤1 µg/ml) and intermediate (MIC ≤2 µg/ml) pathogenic bacteria, were 2.1 and 4.2 mg/kg/day by i.v. route and 3.9 and 7.8 mg/kg/day by i.m. route.     

Serum C-reactive protein and iron levels following gonadectomy are not modified by perioperative administration of robenacoxib to dogs

The aim of this study was to evaluate the perioperative effects of robenacoxib on serum C-reactive protein (CRP) and iron concentrations in dogs undergoing gonadectomy. In a prospective, blinded, controlled clinical trial, 60 healthy dogs were randomly assigned to receive preoperative subcutaneous injection of either robenacoxib [2 mg/kg body weight (BW)], meloxicam (0.2 mg/kg BW), or saline (0.04 mL/kg BW), followed by oral administration over 72 h (robenacoxib: 2 to 4 mg/kg BW; meloxicam: 0.1 mg/kg BW; saline: gelatin capsules). Blood samples were taken before surgery and 12, 24, 48, 72 h, and 7 d after surgery. Pain scores were assessed via the short-form Glasgow Composite Pain Scale over 72 h postoperatively. C-reactive protein (CRP) and iron serum levels increased and decreased (P < 0.01, both), respectively, after surgery and returned to baseline within 1 wk. No differences were observed among treatments (P > 0.05) or based on surgery/gender (P > 0.05). Pain assessment revealed a higher incidence of treatment failure in saline (6 females versus 2 and 1 female in robenacoxib and meloxicam, respectively). In conclusion, robenacoxib and meloxicam had no influence on postoperative CRP or iron in dogs, which suggests that these nonsteroidal anti-inflammatory drugs (NSAIDs) do not have a relevant effect on these biomarkers.     

Long-term Pulmonary Responses to Quadweekly Intermittent Intratracheal Spray Instillations of Magnetite (Fe3O4) Nanoparticles for 52 Weeks in Fischer 344 Rats

Information about potential risks of iron nanomaterials is still limited, while a wide variety of applications are expected. We recently reported acute phase responses of male and female Fischer 344 rats after a single intratracheal spray instillation of Fe₃O₄ nanoparticles (magnetite), clearly showing dose-dependent pulmonary inflammatory changes (Tada et al., J Toxicol Pathol 25, 233–239, 2012). The present study assessed long-term responses of male and female Fischer 344 rats to multiple administrations of magnetite. Ten-week-old male and female Fischer 344 rats (n=20/group) were exposed to a total of 13 quadweekly intermittent intratracheal spray instillations of magnetite during the experimental period of 52 weeks, at doses of 0, 0.2 (low), 1.0 (medium) and 5.0 (high-dose) mg/kg body weight per administration. Absolute and relative lung weights of the high-dose group were significantly higher than those of the control group. Macroscopically, slight enlargement and scattered black patches were recognized in the lungs and the lung-associated lymph nodes of the high-dose group. Histopathologically, infiltration of macrophages phagocytosing magnetite (all dose groups) and of chronic inflammatory cells (medium- and high-dose males and high-dose females), alveolar bronchiolization and granuloma (high-dose group) were observed. In addition, alveolar hyperplasias were observed in some rats of the high-dose group, and cytoplasmic overexpression of β-catenin protein was immunohistochemically found in such lesions. The present results clearly show that instilled magnetite causes chronic inflammatory responses in the lung. These responses occur in a dose-dependent manner without apparent differences among sexes     

Characteristics of prolactin-releasing response to salsolinol in vivo in cattle

The aims of the present study were to clarify the effect of salsolinol (SAL), a dopamine (DA)-derived endogenous compound, on the secretion of prolactin (PRL) in cattle. The experiments were performed from April to June using calves and cows. A single intravenous (i.v.) injection of SAL (5 mg/kg body weight [BW]) or sulpiride (a DA receptor antagonist, 0.1 mg/kg BW) significantly stimulated the release of PRL in male and female calves (P < 0.05), though the response to SAL was smaller than that to sulpiride. The secretory pattern of PRL in response to SAL or sulpiride in female calves resembled that in male calves. A single i.v. injection of SAL or sulpiride significantly stimulated the release of PRL in cows (P < 0.05). There was no significant difference in the PRL-releasing response between the SAL- and sulpiride-injected groups in cows. A single intracerebroventricular injection of SAL (10 mg/head) also significantly stimulated the release of PRL in castrated calves (P < 0.05). These results show that SAL is involved in the regulatory process for the secretion of PRL, not only in male and female calves, but also in cows. The results also suggest that the potency of the PRL-releasing response to SAL differs with the physiological status of cattle.     

The fate and tissue disposition of deoxynivalenol in broiler chickens

To evaluate the fate of deoxynivalenol (DON) in broilers, DON was administered either intravenously or orally to broilers at a dose of 1 mg/kg BW. Concentrations of DON in plasma were measurable up to 4 hr and 2 hr after intravenous and oral administration, respectively. Following intravenous administration, the values for the elimination half-life, the volume of distribution and the clearance were 1.25 ± 0.25 hr, 7.55 ± 2.03 l/kg and 4.16 ± 0.42 l/hr/kg, respectively. The oral bioavailability was 15.46 ± 4.02%. DON was detectable in all tissues examined after oral administration. These results suggest that DON is able to penetrate into the various tissues in broilers, though poorly absorbed from their gastrointestinal tract.     

Supplementary dietary nitric oxide donor (sodium nitroprusside) or inhibitor (NG-nitro-l-arginine methyl ester) depressed growth performance and ovarian primordial and primary follicles in Japanese quail (Coturnix coturnix japonica) in a dose-dependent manner

1. The aim of the study was to determine the effects of dietary supplementation with sodium nitroprusside (SNP), a nitric oxide (NO) exogenous donor, and N^G-nitro-l-arginine methyl ester (l-NAME), a NO inhibitor, on growth performance, some biochemical parameters and ovarian primordial and primary follicles of quail.

2. A total of 480 Japanese quail (Coturnix coturnix japonica), one-day-old, including both males and females, were randomly allocated into one control group and 4 treatment groups each consisting of 96 birds. The control group was fed on the basal diet, whereas the experimental groups were fed on the basal diet supplemented with 50 mg SNP/kg, 200 mg SNP/kg, 50 mg l-NAME/kg or 200 mg l-NAME/kg.

3. In the group receiving 200 mg SNP/kg, BW was lower on d 28 and d 42 compared to the control group and body weight gain (BWG) was lower between weeks 2 and 4 compared to the control group. In the same group, BWG and feed consumption were lower compared with the control group. In the group receiving 200 mg l-NAME/kg, BW on d 42 and BWG were lower, whereas feed consumption and FCR was higher than in the control group.

4. In the groups supplemented with SNP at 50 and 200 mg/kg, serum total protein and albumin were higher than the control group; however, serum lipid profile, and liver and kidney enzymes were not affected by supplementation with SNP or l-NAME.

5. The numbers of ovarian primordial and primary follicles were greater in the group fed on the diet supplemented with 200 mg SNP/kg compared with the control group. Supplementation at 200 mg l-NAME/kg diet reduced the number of primary follicles compared to the controls, whereas the diameter of primordial and primary follicles increased.

6. In conclusion, supplementation with SNP and l-NAME depressed quail growth. Furthermore, the increase in NO following dietary supplementation with the NO-donor SNP delayed the growth process from primordial to primary and primary to secondary follicle transition in quail.

     

Effects of dietary iron level on growth performance,hematological status,and intestinal function in growing-finishing pigs

This study investigated the different addition levels of iron (Fe) in growing-finishing pigs and the effect of different Fe levels on growth performance, hematological status, intestinal barrier function, and intestinal digestion. A total of 1,200 barrows and gilts ([Large White × Landrace] × Duroc) with average initial body weight (BW; 27.74 ± 0.28 kg) were housed in 40 pens of 30 pigs per pen (gilts and barrows in half), blocked by BW and gender, and fed five experimental diets (eight replicate pens per diet). The five experimental diets were control diet (basal diet with no FeSO₄ supplementation), and the basal diet being supplemented with 150, 300, 450, or 600 mg/kg Fe as FeSO₄ diets. The trial lasted for 100 d and was divided into the growing phase (27 to 60 kg of BW) for the first 50 d and the finishing phase (61 to 100 kg of BW) for the last 50 d. The basal diet was formulated with an Fe-free trace mineral premix and contained 203.36 mg/kg total dietary Fe in the growing phase and 216.71 mg/kg in the finishing phase based on ingredient contributions. And at the end of the experiment, eight pigs (four barrows and four gilts) were randomly selected from each treatment (selected one pig per pen) for digesta, blood, and intestinal samples collection. The results showed that the average daily feed intake (P = 0.025), average daily gain (P = 0.020), and BW (P = 0.019) increased linearly in the finishing phase of pigs fed with the diets containing Fe. On the other hand, supplementation with different Fe levels in the diet significantly increased serum iron and transferrin saturation concentrations (P < 0.05), goblet cell numbers of duodenal villous (P < 0.001), and MUC4 mRNA expression (P < 0.05). The apparent ileal digestibility (AID) of amino acids (AA) for pigs in the 450 and 600 mg/kg Fe groups was greater (P < 0.05) than for pigs in the control group. In conclusion, dietary supplementation with 450 to 600 mg/kg Fe improved the growth performance of pigs by changing hematological status and by enhancing intestinal goblet cell differentiation and AID of AA.     

Potential application of Fe-methionine as a feed supplement on improving the quality of broilers breast meat

A total of 250 one-day-old Ross 308 male chicks were used to investigate the effects of Fe-methionine (Fe-met) and iron sulfate (FeSO₄.7H₂O) on performance, mineral concentration, meat quality, and oxidative stability of breast. The feeding experiment was performed with five dietary groups including group I (basal diet [BD] + 80 mg/kg FeSO₄), group II (BD + 60 mg/kg FeSO₄ + 20 mg/kg Fe-met), group III (BD + 40 mg/kg FeSO₄ + 40 mg/kg Fe-met), group IV (BD + 20 mg/kg FeSO₄ + 60 mg/kg Fe-met), and group V (BD + 80 mg/kg Fe-met). The results showed that Fe and Cu content in the breast muscle increased by dietary supplementation of organic and inorganic iron from II to V groups. Dietary groups of II, IV, and V increased L* value and b* value of breast meat. Additionally, redness of breast meat enhanced linearly and quadratically by dietary supplementation of 80 mg/kg Fe as FeSO₄. In addition, dietary supplementation Fe from II to V groups led to a significant increase in pHu at 24-h postmortem while it was negatively correlated with L* value of breast muscle. This study demonstrates that replacing FeSO₄ with Fe-Met could improve breast meat yield of broilers. Although 80 mg of Fe-Met improved the iron content of meat, it showed detrimental effects on the lipid oxidation of breast meat.     

The anthelmintic efficacy of five plant products against gastrointestinal trichostrongylids in artificially infected lambs

Forty-eight helminth-free lambs were divided into eight groups (A-H) of six animals. Groups A-G were infected artificially with 10,000 third stage larvae of Haemonchus contortus and 20,000 third stage larvae of Trichostrongylus colubriformis, whereas group H remained uninfected. Thirty days post-infection the lambs were treated orally with a single dosage of one of the following products: group A with 3 mg/kg body weight (BW) of an aqueous ethanol extract (70%, v/v) of the seeds of Azadirachta indica A. Juss syn. Melia azedarach L. (Meliaceae); group B with 1 g/kg BW of a raw powder of the leaves of Ananas comosus (L.) Merr. (Bromeliaceae); group C with 0.3 mg/kg BW of an aqueous ethanol extract of a 1:1 mixture (g/g) of Vernonia anthelmintica (L.) Willd. (Asteraceae) seeds and Embelia ribes Burm (Myrsinaceae) fruits; group D with 183 mg/kg BW of an aqueous ethanol extract of the whole plants of Fumaria parviflora Lam. (Fumariaceae); group E with 28 mg/kg BW of an aqueous ethanol extract of the seeds of Caesalpinia crista L. (Caesalpiniaceae); group F with 25 mg/kg BW of pyrantel tartrate and group G with 50% ethanol. Group H remained untreated. Only the ethanol extract of F. parviflora caused a strong reduction of the faecal egg counts (100%) and a 78.2 and 88.8% reduction of adult H. contortus and T. colubriformis on day 13 post-treatment. The extract was as effective as the reference compound pyrantel tartrate. Therefore, the ethanol extract itself or single constituents of F. parviflora could be a promising alternative source of anthelmintic for the treatment of gastrointestinal trichostrongylids in small ruminants.     

Effects of hypothalamic dopamine on growth hormone‐releasing hormone‐induced growth hormone secretion and thyrotropin‐releasing hormone‐induced prolactin secretion in goats

The aim of the present study was to clarify the effects of hypothalamic dopamine (DA) on the secretion of growth hormone (GH) in goats. The GH‐releasing response to an intravenous (i.v.) injection of GH‐releasing hormone (GHRH, 0.25 μg/kg body weight (BW)) was examined after treatments to augment central DA using carbidopa (carbi, 1 mg/kg BW) and L‐dopa (1 mg/kg BW) in male and female goats under a 16‐h photoperiod (16 h light, 8 h dark) condition. GHRH significantly and rapidly stimulated the release of GH after its i.v. administration to goats (P < 0.05). The carbi and L‐dopa treatments completely suppressed GH‐releasing responses to GHRH in both male and female goats (P < 0.05). The prolactin (PRL)‐releasing response to an i.v. injection of thyrotropin‐releasing hormone (TRH, 1 μg/kg BW) was additionally examined in male goats in this study to confirm modifications to central DA concentrations. The treatments with carbi and L‐dopa significantly reduced TRH‐induced PRL release in goats (P < 0.05). These results demonstrated that hypothalamic DA was involved in the regulatory mechanisms of GH, as well as PRL secretion in goats.     

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.     

Babesia vulpes in a dog from Prince Edward Island,Canada

A 12-year-old neutered male American Staffordshire terrier dog was referred to the Atlantic Veterinary College, Prince Edward Island, Canada, for suspected immune-mediated hemolytic anemia. Babesiosis (Babesia vulpes) was confirmed using polymerase chain reaction testing. The dog was successfully treated with a 10-day protocol of atovaquone/proguanil (TEVA Pharmaceutical Industries, Toronto, Ontario), 13.5 mg/kg BW, PO, q8h and azithromycin (Pharmascience, Montreal, Quebec), 10 mg/kg BW, PO, q24h. To the authors’ knowledge, this report is the first documented case of babesiosis caused by Babesia vulpes in a dog from Canada.     

Designing a treatment protocol with voriconazole to eliminate Aspergillus fumigatus from experimentally inoculated pigeons

To investigate the efficacy of voriconazole for the treatment of aspergillosis, three groups of six racing pigeons (Columba livia domestica) were inoculated in the apical part of the right lung with 2 × 10⁷ conidia of an avian derived Aspergillus fumigatus strain. The minimal inhibitory concentration of voriconazole for this strain was 0.25 μg/ml. In two groups, voriconazole treatment was started upon appearance of the first clinical signs and continued for fourteen days. The third group was sham treated. The voriconazole-treated pigeons received voriconazole orally at a dose of 10 mg/kg body weight (BW) q12h (group 1) or 20 mg/kg BW q24h (group 2). Sixteen days post-inoculation all surviving pigeons were euthanized. Weight loss, clinical scores, daily mortality, lesions at necropsy and isolation of A. fumigatus were compared between all groups. In both voriconazole-treated groups, a significant reduction in clinical signs and lesions was observed. Administering voriconazole at 10 mg/kg BW q12h eliminated A. fumigatus and administering voriconazole at 20 mg/kg BW q24h reduced A. fumigatus isolation rates. Mild histological liver abnormalities were found in group 1 (10 mg/kg BW q12h), while mild histological as well as macroscopic liver abnormalities were found in group 2 (20 mg/kg BW q24h).In conclusion, voriconazole at 10 mg/kg BW q12h in pigeons reduces clinical signs and eliminates A. fumigatus in racing pigeons experimentally infected with A. fumigatus.     

ORIGINAL ARTICLE: Changes in composition a metabolism of caecal microbiota in rats fed diets supplemented with copper‐loaded chitosan nanoparticles

The study was conducted to investigate the effect of copper‐loaded chitosan nanoparticles on the composition and metabolism of the caecal microbiota in rats. Forty male Sprague–Dawley (SD) rats (average body weight of 82 ± 5 g) were randomly assigned to five groups (n = 8). The dietary treatments were: (i) basal diet, (ii) basal diet + 80 mg/kg BW CuSO₄, (iii) basal diet + 80 mg/kg BW chitosan (CS‐I), (iv) basal diet + 80 mg/kg BW copper‐loaded chitosan nanoparticles (CSN‐I) and (v) basal diet + 160 mg/kg BW copper‐loaded chitosan nanoparticles (CSN‐II). The trial lasted 21 days. The results showed that compared with control, Average day gain (ADG) of group CSN‐I and CSN‐II increased (p < 0.05). No significant difference was found in CuSO₄ or CS‐I‐treated groups (p > 0.05). There were no effects of these treatments on average day feed intake (ADFI) of rats (p > 0.05). The counts of Bifidobacteria and Lactobacillus in group CSN‐II were higher than those of the control group (p < 0.05), while the counts of total aerobes, total anaerobes, Salmonella, Clostridium and coliform were lower than those of the control (p < 0.05). The activity of β‐glucuronidase in group CSN‐I or CSN‐II was significantly depressed (p < 0.05), while the activities of α‐galactosidase and β‐galactosidase were enhanced significantly (p < 0.05). The pH of the caecum digesta and the concentration of propionate and butyrate in group CSN‐I and CSN‐II were higher than those of the control group (p < 0.05). No significant difference was found in these parameters in CuSO₄ or CS‐I‐treated groups (p > 0.05). The results indicate that the microbiota and environment of caecum are beneficially changed by the administration of copper‐loaded CSN.     

Protective effects of silymarin on fumonisin B1-induced hepatotoxicity in mice

The present study was conducted to investigate the effect of silymarin on experimental liver toxication induced by Fumonisin B₁ (FB₁) in BALB/c mice. The mice were divided into six groups (n = 15). Group 1 served as the control. Group 2 was the silymarin control (100 mg/kg by gavage). Groups 3 and 4 were treated with FB₁ (Group 3, 1.5 mg/kg FB₁, intraperitoneally; and Group 4, 4.5 mg/kg FB₁). Group 5 received FB₁ (1.5 mg/kg) and silymarin (100 mg/kg), and Group 6 was given a higher dose of FB₁ (4.5 mg/kg FB₁) with silymarin (100 mg/kg). Silymarin treatment significantly decreased (p < 0.0001) the apoptotic rate. FB₁ administration significantly increased (p < 0.0001) proliferating cell nuclear antigen and Ki-67 expression. Furthermore, FB₁ elevated the levels of caspase-8 and tumor necrosis factor-alpha mediators while silymarin significantly reduced (p < 0.0001) the expression of these factors. Vascular endothelial growth factor (VEGF) and fibroblast growth factor-2 (FGF-2) expressions were significantly elevated in Group 4 (p < 0.0001). Silymarin administration alleviated increased VEGF and FGF-2 expression levels (p < 0.0001). In conclusion, silymarin ameliorated toxic liver damage caused by FB₁ in BALB/c mice.     

地胆头提取物的急性和亚急性毒性研究

采用650mL／L乙醇热回流浸提结合冰冻干燥法,制备了地胆头提取物。分别给昆明种雄性小鼠腹腔注射不同剂量的地胆头提取物,研究该提取物对小鼠的急性毒性和亚急性毒性试验。结果表明,地胆头提取物对供试小鼠腹腔注射的LD50为2123．24mg／kg,959／6可信限为1742.86mg／kg～2503．62mg／kg,地胆头提取物对供试小鼠属于低毒。亚急性毒性试验结果表明,地胆头提取物未引起供试小鼠临床表现和体重异常,未引起心、肺和肾等脏器的病理变化,但高剂量的地胆头提取物能够导致肝脏中央静脉轻度充血。