2011 Cilt 30 Sayı 1

Permanent URI for this collectionhttps://hdl.handle.net/11452/13940

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    Ecopharmacokinetics of tetracyclines and sulfonamides in soil
    (Uludağ Üniversitesi, 2011-07-11) Cengiz, Murat; Oruç, Hasan Hüseyin; Uzunoğlu, İlknur; Sonal, Songül; Özsoy, Gökhan; Uludağ Üniversitesi/Veteriner Fakültesi.; Uludağ Üniversitesi/Ziraat Fakültesi.; Uludağ Üniversitesi/Sağlık Bilimleri Enstitüsü.
    The aims of this study were to evaluate the elimination of oxytetracycline, chlortetracycline, sulfadiazine and sulfamethoxazole from soil, and to investigate the influence of pH and the rainfall on elimination of the antibiotics. To detect antibiotic concentrations, leachate samples were collected from soil columns. The antibiotics were extracted by solid phase extraction and analysed by high performance liquid chromatography system. To determine elimination half-life of the antibiotics from soil and relationship between measured parameters, first-order kinetics and statistical analyses were applied to all collected data. Half-life of sulfadiazine and sulfamethoxazole in leachate waters 19 days after treatment was 0.24 hour and this was increased up to 2.25 hours sulfamethoxazole and 3.57 hours sulfadiazine 33 days after treatment. A half-life for tetracyclines was not detected, since there was not consistent trend for the transport of tetracyclines between soil and water compartments. The results of regression analyses showed that the concentrations of antibiotics in the same group changed at the same rate. The pH of leachate samples was positively influenced by increases in rainfall and days after treatment. A significant relationship was not found between the antibiotic concentrations and both pH and rainfall.
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    Effects of different dietary energy and protein levels on rumen ph, urea levels and rumen protozoal population in sheep
    (Uludağ Üniversitesi, 2011-07-08) Yıldız, Gültekin; Pişkin, İlksin; Tuncer, Şakir Doğan; Sulu, Nesrin; Yeşilbağ, Derya; Uludağ Üniversitesi/Veteriner Fakültesi.
    The effects of different levels of energy and protein rations on rumen fluid, pH, ammonia, urea levels, kinds and numbers of species of protozoa in sheep are examined in the present experiment. Six male, Merino sheep were utilized in a 6 X 6 Latin square design. The rations were prepared as standard protein and standard energy level /(S-Group 1); low energy (LE-Group 2); low protein (LP-Group 3); high protein (HP-Group 4); high energy (HE-Group 5) and 10 g/day bicarbonate added to the high energy (HE+HCO3-Group 6). The experimental period extended to 10 days feeding period for each ration. Rumen fluid samples were taken from animals 0 hours before feeding as well as in the 2nd and the 4th hours after feeding during the last two days of feeding period. The end of the experiment time and feed factor showed statistically significant differences in pH values (P<0.05). The lowest pH level was observed in sheep fed ration HE+HCO3 before feeding time and pH levels were not statistically significant in the 2nd and 4th hours after feeding. It was found that the ammonia level in animals fed HP ration was the lowest (P<0.05) before feeding. Differences among time factors were found to be statistically significant (P<0.05) before feeding and 4th hours after feeding. Among the protozoa species Entodinium minimum was the most common species. Differences among feed factors for Entodinium caudatum level are found to be statistically significant (P<0.05).
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    Physiological mechanisms of multiple ovulations and factors affecting twin calving rates in cattle
    (Uludağ Üniversitesi, 2011-05-09) Çobanoğlu, Özden; Uludağ Üniversitesi/Veterinerlik Fakültesi.
    Reproduction in bovine is affected by several different factors. These factors explain some of the variations observed in the reproductive efficiency of animals. Several comprehensive studies were conducted to assess the incidence of twinning at birth in various dairy and beef cattle breeds. In this manner, many environmental and genetic factors affecting reproductive system have been studied quite extensively. Even if the natural incidence of multiple births in cattle is very low, some variations on the twinning rate can be observed due to the influence of breed differences, the effects of feeding and management systems and also the effects of some environmental sources such as a parity, an age of cow, a season of the year and a geographic location of raised animals. Thus, the main purpose of this review is to emphasize and explain the physiological mechanisms regulating multiple ovulations in cattle and also some of the important factors affecting multiple births positively or negatively on the cow production system.