Effect of supplementation of indigenous browse tree pods on weight gain and carcass parameters of Abergelle rams

The objective of the study was to evaluate the effect of supplementation of indigenous browse tree pods on nutrient intake, digestibility, weight gain, and carcass parameters of local Abergelle rams fed grass hay as a basal diet. This experiment was conducted at the Abergelle Agricultural Research Center farm in Tigray region, northern Ethiopia. Experimental rams were grouped according to their initial body weight (17.4?±?0.95 kg) in a randomized complete block design into three treatments and six replications. Treatments consisted of feeding grass hay free of choice supplemented with pods of either Acacia tortilis (T₁), Faidherbia albida (T₂), or Dichrostachys cinerea (T₃) fed at the rate of 10 g kg^?1 body weight daily. The crude protein (CP) contents of the supplemental feeds in T₁, T₂, and T₃ were 167, 156, and 135 g kg^?1 dry matter (DM), respectively. The CP intake was significantly higher (P?<?0.05) in T₁ and T₂ than that in T₃. No statistical difference (P?>?0.05) was observed in the digestibilities of DM and CP. Final body weight, average daily gain, slaughter weight (SW), hot carcass weight, and ribeye area were not significantly different (P?>?0.05) among the treatments. However, dressing percentage based on SW in T₁ and T₂ was significantly higher (P?<?0.05) than that in T₃. Therefore, from this research, it can be concluded that though the weight gains and carcass weights of experimental rams were not as such remarkable among the treatments, efficient utilization of locally available and cheap browse tree pods as alternative protein supplements to Abergelle sheep during the dry season could be important to small holder farmers.

     

Nitrogen and Phosphorus Use Efficiency in Improved Potato (<Emphasis Type="Italic">Solanum tuberosum</Emphasis> L.) Cultivars in Southern Ethiopia

Use of nutrient efficient crop species or cultivars within species in combination with improved crop production practices offer the best option for meeting the future food requirements of growing world populations. Efficiency improvement has a key role for nutrient use and it improves both productivity of yield and minimizes risks of losses that potentially harm the environment. To improve nutrient use efficiency (NUE), one strategy is to select cultivars of crops with high NUE. Both nitrogen (N) and phosphorus (P) are among essential macronutrients commonly applied to agricultural crops to optimize yields. Evaluation of potato cultivars with high N and P efficiency is essential for sustainable production of the crop. In Ethiopia, however, little research has been done to elucidate better NUE of potato crop until recently. This study was, thus, designed to evaluate selected potato cultivars (Belete, Gudene, Jalene, Marachere and one local check) for NP use efficiency under low levels of the nutrients in Wolaita Sodo University, Ethiopia during 2014 and 2015. Factorial combination of 3 levels of each N (0, 55.5 and 111 kg N ha^?1 ) and P (0, 19.5 and 39 kg P ha^?1 ) were assigned to the main plots and the 5 cultivars to subplots of split-plot design in three replications. Efficiency indices such as agronomic efficiency, physiological efficiency and recovery efficiency were computed for combined NP nutrients. Results showed that agronomic nitrogen use efficiency, apparent phosphorus use efficiency and phosphorus use efficiencies were significantly influenced by the interaction effect of rates of NP nutrition and variety. Application of NP more than 55.5:19.5 kg ha^?1 will not beneficial due to their less or equal use and recovery efficiencies to 55.5:19.5 kg NP ha^?1. Belete was the most NP efficient variety followed by Jalene and Gudene in all efficiency indices. Therefore, Belete, Jalene and Gudene return better for NP at 55.5:19.5 kg ha^?1 for economical use of fertilizes while obtaining satisfactory yield. It can be concluded that yield response variation of the varieties was related to their differences in NP uptake and use efficiencies; and the improved potato varieties were superior to local check in using NP nutrients efficiently.     

Ingestion of indigestible foreign materials by free grazing ruminants in Amhara Region, Ethiopia

Ruminants slaughtered in Bahir-Dar, northern Ethiopia, were studied to estimate the prevalence and types of foreign bodies in the rumen and reticulum. Of the 400 cattle, 320 sheep, and 320 goats examined between November 2011 and May 2012, 41.8, 20.6 and 11.9 %, respectively, contained one or more types of foreign bodies. The prevalence of foreign bodies was significantly (P?<?0.05) higher (i) in cattle than in sheep and goats, (ii) in cattle in poor body condition than those in good condition, and (iii) in the rumen than in the reticulum. The most commonly encountered materials were plastics, which resulted from the widespread use of plastic bags and improper waste disposal. Other materials found were cloth, rope, metal, and leather. The study demonstrated that ruminants in the area are ingesting various types of indigestible foreign bodies, which can hamper their health and productivity. To avert the problem, collaborative intervention schemes need to be applied involving professionals, policy makers, livestock keepers, and environmental activists.     

Pharmacokinetics of a florfenicol-tylosin combination after intravenous and intramuscular administration to beagle dogs

A pharmacokinetic study of a commercial florfenicol-tylosin (2:1) combination product was conducted in six beagle dogs after intravenous (IV) and intramuscular (IM) administration at doses of 10 mg/kg (florfenicol) and 5 mg/kg (tylosin). Serum drug concentrations were determined by a validated high performance liquid chromatography (HPLC) using UV detection. A rapid and nearly complete absorption of both drugs with a mean IM bioavailability of 103.9% (florfenicol) and 92.6% (tylosin), prolonged elimination half-life, and high tissue penetration with steady state volume of distribution of 2.63 l/kg (florfenicol) and 1.98 l/kg (tylosin) were observed. Additional studies, including pharmacodynamic and toxicological evaluation are required before recommendations can be made regarding the clinical application of the product in dogs.     

Allometric scaling of orbifloxacin disposition in nine mammal species: a retrospective analysis

The objective of this study was to analyze the relationship between pharmacokinetic parameters and body weight (W) for orbifloxacin using reported pharmacokinetic data. The parameters of interest: clearance (Cl), volume of distribution at steady state (Vss) and elimination half-life were correlated across nine mammal species, including cattle, dog, rat, rabbit, goat, camel, horse, cat and sheep as a function of W using the conventional allometric equation Y = aW(b), where Y is the pharmacokinetic parameter, W is the body weight, a is the allometric coefficient (intercept) and b is the exponent that describes the relationship between the pharmacokinetic parameter and W. Our estimates (Cl=4.40 W(1.03); Vss=1.10W(1.05)) indicated that the increase in these parameters with W approximates a linear power relationship with slopes being very close to one. Overall, the results of this study indicated that it is possible to use allometry to predict pharmacokinetic variables of orbifloxacin based on W of mammal species.     

Mutant prevention concentration and phenotypic and molecular basis of fluoroquinolone resistance in clinical isolates and in vitro-selected mutants of Escherichia coli from dogs

The antibacterial activity, selection of Escherichia coli (E. coli) mutants and mechanisms of fluoroquinolone resistance were investigated by integrating the minimum inhibitory concentration (MIC), mutant prevention concentration (MPC) and in vitro dynamic model approaches. Difloxacin and orbifloxacin, for which the above information has been scarce, were used. A range of area under curve over a 24h interval (AUC(24h))/MIC ratios and selected E. coli strains were investigated using the dynamic models. Continuous incubation for three days in the presence of difloxacin or orbifloxacin resulted in losses in E. coli susceptibility. An AUC(24h)/MIC (AUC(24h)/MPC)-dependent fluoroquinolone activity and selection of E. coli mutants was confirmed. Maximum losses in susceptibility occurred at AUC(24h)/MIC ratios of 54 (orbifloxacin) and 57.3 (difloxacin). AUC(24h)/MIC ratios of 169.8 (orbifloxacin) and 199.5 (difloxacin) were estimated to be protective against the selection of E. coli mutants, and the corresponding ratios based on AUC(24h)/MPC predictions were 34 (orbifloxacin) and 36.3 (difloxacin). When integrating our in vitro data with pharmacokinetic data in dogs, the conventional clinical doses of both drugs were found to be inadequate to attain the above protective values for 90% of the mutant subpopulation (AUC(24h)/MPC(90)). Both target mutations, esp. at codon 83 (Ser to Leu) of gyrA, and overexpression of efflux pumps contributed to resistance development, with mutants also showing decreased susceptibility to enrofloxacin and marbofloxacin. Additional studies would determine the role of mutations found outside the QRDR, at codon 24 of gyrA, and at codon 116 of parC, and establish the significance of these observations in vivo.