Satureja hortensis as a growth promoter in broiler chickens

Satureja hortensis is a popular herb in most regions of the world with leaves used as seasoning. Evidence shows that this plant contains phenolic components such as thymol and carvacrol with a relatively wide spectrum of antimicrobial activity. This study aimed at evaluating the efficacy of S. hortensis plant powder as an alternative to antimicrobial growth promoters in broiler diets. The plant was bought in sufficient quantity from the district of Yasouj, Iran and was dried and ground into powder. A total of 140 unsexed 1-day-old Arbor Acers breed broiler chicks were housed and fed a starter diet up to 18 days of age. The birds were then randomly divided into two groups and reared under similar conditions. Chickens received either normal grower [from 18 to 35 days of age] and finisher [from 36 to 50 days of age] diets without S. hortensis [group I] or a similar diet containing one percent plant powder [group II]. Statistical comparison of average body weights at various time intervals showed that chickens in group II [1930 +/- 29 g, n=63] were significantly [P<0.05] heavier than the birds in the control group [1837 +/- 25 g, n=62]. The average body weight of males in each group [2075 +/- 42 g, n=20 and 2143 +/- 40 g, n=22 for groups I and II, respectively] was also greater than those of the females [1724 +/- 34 g, n=42 and 1808 +/- 30 g, n=41 for groups I and II, respectively]. Although feed conversion ratio was slightly less in group II [1.95], it was not substantially different from that in group I [2.02]. It is concluded that S. hortensis might be a potential growth promoter in poultry

[ECG alterations and changes in biochemical parameters associated with experimental salinomycin toxicosis in sheep]

Salinomycin is a rnonocarboxylic polyether ionophore with antimicrobial properties. It is a dietary additive used as a growth promoter for ruminants and as a coccidiostat in chickens. The mechanism of action of ionophores at the cellular level is to selectively bind certain ions creating intra and extracellular biochemical disturbances. Clinical signs of ionophore intoxication are non specific and similar in all species and include tachycardia, muscle tremor, restlessness, loss of appetite, incoordination, muscular weakness and continual panting. The present study was conducted to determine the changes in ECG parameters and possible arrhythmias and their types due to experimental salinomycin toxicosis in sheep. Acute toxicity with the ionophore [0.5 mg/kg; intravenously] was induced in 6 mixed breed female sheep. A corresponding volume of sterile saline was intravenously injected in each control sheep [n=6]. Blood samples were collected before and at various time intervals after the administration of either salinomycin or saline solutions. Following centrifugation, serum biochemical parameters [ALT, AST, CK, LDH and total protein] were measured using conventional laboratory methods. In both groups, the heart sounds of sheep were carefully monitored and the electrocardiogram [ECG] was recorded. Salinomycin caused a significant [P<0.05] increase in the levels of ALT, AST, LDH and CK in the experimental animals. The mean heart rate in the control group was significantly lower than that in the experimental sheep. Numerous arrhythmias such as sinus tachycardia [11 cases], ventricular premature contraction [2 cases] and T-wave inversion [3 cases] were recorded in the experimental sheep. Acute salinomycin intoxication seems to cause numerous arrhythmias in sheep which might be due to the pathological effect of the ionophore on the myocardium

Antibacterial effects of Iranian native sour and sweet pomegranate [Punica granatum] peel extracts against various pathogenic bacteria

Nowadays, uncontrolled and frequent use of antibiotics may cause emergence of microbial resistance among pathogenic agents. Therefore, the use of new synthetic and natural antimicrobial compounds is inevitable. One source of natural compounds in this respect comes from plants. The purpose of this study was to examine the antibacterial effects of peel extracts from sour and sweet pomegranate. Methanolic extracts of sour and sweet pomegranate peels and aqueous solutions of tetracycline and chloramphenicol were prepared. Antibiogram tests using disk diffusion technique and serial dilution method were performed against ten pathogenic bacteria isolated from animals, and relative minimum inhibitory concentration [MIC] and minimum bactericidal concentration [MBC] values were also determined for the above compounds. The greatest zone of inhibition induced by the action of pomegranate peel extracts was obtained for Staphylococcus aureus [about 25 mm] and the smallest zone of inhibition was obtained for Pasteurella multocida [about 9 mm]. In addition, the lowest MIC and MBC values of pomegranate peel extract were obtained for Staphylococcus aureus [7.8 and 62.5 mg/ml, respectively]. Results of serial dilution tests indicate that bactericidal effect of sour pomegranate peel extract was more than that for sweet pomegranate peel extract; and sweet pomegranate peel extract exerts a bacteriostatic action against bacteria. The antibacterial effect was greater against Gram-positive bacteria compared to that for the Gram-negative bacteria. Effects of these extracts were considerably lower than those for tetracycline and chloramphenicol. In conclusion, methanolic extracts of pomegranate peels exhibit relatively good bacteriostatic and bactericidal effects

[Effects of addition of berberis vulgaris root powder to the arbor acers chicks ration as arowth promoter]

Barberry [Berberis vulgaris L. family Berberidaceae] is well known in Iran, and various parts of this plant including its root, bark, leaf and fruit have been used in folk medicine. There are evidences that this plant contains several antibacterial agents and has been used as a food additive. This experiment was conducted to evaluate the effects of Berberis vulgaris root powder in the diets of broiler chickens on growth performance. One hundred thirty Arbor Acers day old chicks from both sexes [mean of Body weight: 40 g] were divided into two equal groups in a completely randomized design. Dried roots of Berberis vulgaris were powdered and added to the ration of experimental group at a rate of 1%. The measured traits in this study were: live body weight, feed consumption and eventual side effects [gross and histopathological lesions]. Tissue samples of heart, liver and skeletal muscles were collected and fixed in 10% buffered formalin for histopathologic examination. Data were analyzed by two independent sample t-test, using SPSS/PC software. At six weeks of age, there was a significant and greater weight gain in chickens of experimental group [means +/- S.D in experimental groups was 1822.2 +/- 75.1 g versus 1662.8 +/- 85.2 g in control group] [p

[In vitro antibacterial effects of marbofloxacin on microorganisms causing mastitis in cows]

Mastitis, inflammatory disease of mammary glands, can be caused by various microorganisms. Many antimicrobial agents have been evaluated to combat the causative agents. Development of resistance in pathogens against conventional antibiotics may be high; hence at present study in vitro efficacy of a new fluoroquinolone antibiotic [marbofloxacin] against isolated pathogens from clinical mastitis was examined. Milk samples [73] were taken from 28 dairy farms around Shiraz. Staphylococcus aureus [24.1%], Escherichia coli [18.1%], Streptococcus dysgalactiae [9.3%], Corynebacterium bovis [9.3%], Staphylococcus epidermidis [3.7%] and Pseudomonas aeruginosa [3.7%] were identified among 54 bacterial isolates. Antibiotic sensitivity test [Kirby-Bauer method] was carried out for marbofloxacin, enrofloxacin, gentamicin, penicillin and tetracycline. Minimum inhibitory concentration [MIC] and minimum bactericidal concentration [MBC] of marbofloxacin against sensitive bacteria were also determined. Results showed that we all isolated bacteria were sensitive to marbodloxacin, sensitivities against other antibiotics varied from zero to 94.1%. The values obtained as MIC and MBC of marbofloxacin against three bacterial isolates [Staphylococcus aureus, Streptococcus agalactiae, and Staphylococcus epidermidis] were in the range of 0.2 to 1.56 micro g/ml and 0.8 to 6.25 micro g/ml, respectively. Since the isolated bacteria showed adequate sensitivities to fluroquinolones, it is concluded that marbofloxacin can successfully be used for treatment of affected cows with clinical mastitis

Pharmacokinetics of tetracycline hydrochloride after single intravenous injection in dogs

Six mixed-breed apparently healthy dogs were intravenously administered a single dose of tetracycline hydrochloride [50 mg/kg] to evaluate the pharmacokinetic parameters of the drug. Blood samples were collected before and at various time intervals after the administration of the drug. Serum tetracycline concentrations were determined over a 24 h period using fluorescence spectrophotometry. Non-compartmental analysis of the data indicated that tetracycline has a half-life of 4.4 h, a body clearance of around 0.7 ml/kg. min and a volume of distribution of about 0.3 L/kg. The pharmacokinetics of tetracycline found in this study is favourable for therapeutic use in the dog

Pharmacokinetics of tetracycline hydrochloridein fat-tailed sheep

Tetracycline may be used to treat several types of bacterial diseases in ruminants. In addition, tetracycline is added to food to promote the growth. There are few reports on the pharmacokinetics of tetracycline in sheep. Therefore, the objective of this study was to examine the pharmacokinetic characteristics of the drug in sheep. Ten apparently healthy mixed-breed sheep were administered 20 mg/kg tetracycline orally and intravenously with a time interval of two weeks. Blood samples were collected before and at various time intervals after the administration of the drug. Sera were separated, kept at -20°C, and analysed using fluorescence spectrophotometry. The volume of distribution [V[d]], elimination rate constant [K[el]], half-life [t[1/2], and clearance [C1[b]] of tetracycline after intravenous injection were determined to be 0.21 L/kg, 0.21/hr, 3.3 hr, and 0.73 ml/kg/mm, respectively. When the drug was given orally, these parameters were found to be 0.37 L/kg, 0.12/hr, 5.8 hr, and 0.73 ml/kg/min, respectively. Moreover, the bioavailability of tetracycline after oral administration was around 55%

[In vitro antibacterial activity of eugenol and its sodium salt]

Useful effects of many medicinal plants were reported in the literature, among which antibacterial, antiviral and antifungal effects are the most important. In the present study, antibacterial effects of eugenol was examined. Experimental study. Serial dilution antibiotic susceptibility tests were performed to determine minimum inhibitory concentration [MIC] and minimum bactericidal concentration [MBC] against different Gram positives bacterial species including: Staphylococcus aureus, Sterptococcus agalactiae, Corynebacterium Pseudotuberculosis, Enterococcus faecalis, Bacillus cereus, Clostridium perfringens, and Listeria monocytogenes serotype 4b and Gram negative including: Escherichia coli K12 serotype, Salmonella typhimurium P649 serotype, Pasteurella multocida, and Pseudomonas aeruginosa]. MIC values for different bacterial species varied from 10 microg/ml for Pasteurella multocida to more than 6 mg/ml for Pseudomonas aeruginosa. MBC values were mostly the same as corresponding MICs. In addition, Pasteurella multocida and Streptococcus agalactiae showed comparable susceptibilities to eugenol and its sodium salt, but other microorganisms had greater susceptibility to eugenol than its sodium salt. Bacterial species of this experiment had different sensitivities to eugenol and its sodium salt

Effect of aspirin on the disposition of tetracycline in sheep

Aspirin has been shown to increase the rate of urinary excretion of tetracycline in humans. To understand the mechanisms involved in this drug interaction, the effect of aspirin on the kinetics of tetracycline was investigated in sheep. Tetracycline was administered intravenously in six mixed-breed sheep at various stages: first, tetracycline alone; second, immediately after intravenous injection of salicylic acid and third, three hours following oral administration of tetracycline. Blood samples were collected during 6 hours after administration of tetracycline followed by the separation of sera. Tetracycline content of each sample was assayed using fluorescence spectroscopy. The concentration of tetracycline in the first blood sample was higher when tetracycline was administered alone compared with those given after oral aspirin or with salicylic acid. Serum tetracycline concentration was more rapidly approached to the minimum when it was administered in conjunction with salicylic acid. In addition, the area under the curve for serum tetracycline concentration versus time [AUC] was smaller compared to when tetracycline was administered alone. In contrast, when aspirin was given orally prior to the intravenous administration of tetracycline, the rate of decline in serum tetracycline concentration was less and AUC was higher compared to when it was injected alone. As the underlying mechanism[s] will have pharmacokinetics impact, which may be important in clinical pharmacology point of view, further in vivo and in vitro studies should be carried out to elucidate the exact nature of the interaction between these drugs