The pharmacokinetics of cytarabine administered subcutaneously,combined with prednisone,in dogs with meningoencephalomyelitis of unknown etiology

The objective of this study was to describe the pharmacokinetics (PK) of cytarabine (CA) after subcutaneous (SC) administration to dogs with meningoencephalomyelitis of unknown etiology (MUE). Twelve dogs received a single SC dose of CA at 50 mg/m² as part of treatment of MUE. A sparse sampling technique was used to collect four blood samples from each dog from 0 to 360 min after administration. All dogs were concurrently receiving prednisone (0.5–2 mg kg^?1day^?1). Plasma CA concentrations were measured by HPLC, and pharmacokinetic parameters were estimated using nonlinear mixed‐effects modeling (NLME). Plasma drug concentrations ranged from 0.05 to 2.8 μg/ml. The population estimate (CV%) for elimination half‐life and Tmax of cytarabine in dogs was 1.09 (21.93) hr and 0.55 (51.03) hr, respectively. The volume of distribution per fraction absorbed was 976.31 (10.85%) ml/kg. Mean plasma concentration of CA for all dogs was above 1.0 μg/ml at the 30‐, 60‐, 90‐, and 120‐min time points. In this study, the pharmacokinetics of CA in dogs with MUE after a single 50 mg/m² SC injection in dogs was similar to what has been previously reported in healthy beagles; there was moderate variability in the population estimates in this clinical population of dogs.     

Effects of replacing fish oil with stearine as main lipid source in diet on growth and survival of Pacific White Shrimp,Litopenaeus vannamei (Boone, 1931)

The stearine fraction from raw fish oil refinement has been treated as a waste material. This study was conducted to evaluate effects of replacing prime refined fish oil with stearine as the main lipid source to a control diet on shrimp growth and survival as well as on pellet water stability of diets. Test diets were processed containing three levels (0.7%, 1.3% and 2.7%) of either stearine or refined fish oil in a semi‐purified control diet. These diets were each assigned to five or six replicated tanks and each tank was stocked with seventeen juvenile shrimp (ca. 0.50 g) in an indoor seawater recirculating system. At the end of 6 weeks, the survival of shrimp was 89.4–95.3% with no significant difference (P > 0.05) among dietary treatments. The six test diets obtained significantly higher (P < 0.05) shrimp growth rates (1.46–1.83 g week^?1) than the control diet (1.38 g week^?1). The shrimp that were fed the three stearine‐added diets exhibited high growth rates (1.75–1.83 g week^?1). Increasing the inclusion level of the stearine improved pellet water stability (91.7–93.9%; P < 0.05). These results suggest that stearine can replace fish oil in shrimp feed based on the growth performance.     

A comparative study of energy utilisation by the laying hen from diets containing a high proportion of fat and diets made up mainly from carbohydrate sources

An experiment was carried out in which laying hens were fed diets containing about 30 per cent tallow at three protein levels. Productive performances of hens on these diets were compared with those of hens fed either a diet containing 15 per cent arachis oil, a diet containing 15 per cent sucrose or a conventional cereal‐based control diet.

It was found that the best performance was obtained with hens fed the control diet. Gross energetic efficiency of egg production was slightly lower in the birds fed the diets containing arachis or sucrose. It appeared that the lower efficiency was due to the higher mean body weight of birds on these diets. Egg size was significantly increased by feeding the diet containing arachis oil.

Performance of hens given diets containing tallow was unsatisfactory. For each diet egg production was significantly less than that recorded for the control diet and the gross energetic efficiency of egg production was much lower than that on the control diet.     

Enhancement of Gonad Production in the Sea Urchin Loxechinus albus in Chile Fed Extruded Feeds

Loxechinus albus were fed algae ( Macrocystis pyrifera and Ulva sp.) and two feeds prepared by extrusion (one containing kelp). Results were the same for individuals maintained in suspended cages in the sea and in aquaria on land. Gonads increased in size in individuals fed extruded feeds and decreased in individuals fed algae during the spawning season. Gonads increased ca. four-fold in size in individuals fed the extruded feeds during the post-spawning season, much greater than those fed algae. Individuals fed extruded feeds had a lower feeding rate than individuals fed algae on a wet-weight but not on a dry-weight basis. The extruded feed supports gonadal growth more than natural food and has potential for use for aquaculture of sea urchins.     

Effect of Various Dietary Lipid Levels on Quantitative Essential Fatty Acid Requirements of Juvenile Pacific White Shrimp Litopenaeus vannamei

A 6-wk feeding trial was conducted to evaluate the effect of various dietary lipid levels on quantitative requirements for essential fatty acids (EFA) by juvenile Pacific white shrimp Litopenaeus vannamei . A factorial experiment with three dietary lipid levels (3, 6, and 9%) and three dietary levels (0.5, 1, and 2%) of a mixture of n-3 highly unsaturated fatty acids (HUFA) was used. An increase in quantitative requirements for EFA with increasing supplementation level of dietary lipid was not demonstrated. Results suggested that this shrimp species appeared to be able to satisfy its n-3 HUFA requirements when they were supplied at 0.5% of diet; this dietary level may be even lowered. Moreover, depressed growth was observed in shrimp fed diets with the HUFA mixture supplemented at 2%. In addition, the present study showed that increasing the dietary lipid level had an effect on lipid composition of shrimp, by increasing lipid deposition in hepatopancreas and muscle tissue, but without a significant effect on growth.     

Characterization of water quality factors during intensive raceway production of juvenile Litopenaeus vannamei using limited discharge and biosecure management tools

Disease epizootics have negatively affected production and expansion of the shrimp culture industry. This, along with environmental concerns regarding limited water resources and contamination of receiving streams, has caused the industry to investigate more sustainable and biosecure management practices. A study was conducted to evaluate the effect of limited water exchange on water quality, growth and survival of the Pacific white shrimp Litopenaeus vannamei postlarvae (PL) in greenhouse-enclosed raceways. Concentrations of NH₄-N did not exceed 2.0 mg l⁻¹ during this period; whereas, NO₂-N exceeded 26.4 mg l⁻¹, indicating assimilation of primary amines by primary productivity. Periodic removal of suspended solids by a common pressurized sand filter and injection of oxygen into culture water resulted in high-survival rates for both raceways (97.5 and 106.0%) with an average biomass yield of 4.29 ± 0.06 kg m⁻³. Shrimp samples collected during the nursery trial and at harvest showed no signs of bacterial or viral pathogen infections.     

Protein and energy digestibility and gonad development of the European sea urchin Paracentrotus lividus (Lamarck) fed algal and prepared diets during spring and fall

Protein and energy are two of the main limiting factors for sea urchin growth. However, the requirement of daily protein and energy to maximize gonadal production is still unknown. Paracentrotus lividus were fed three experimental diets: Ulva lactuca, Gracilaria conferta and a prepared diet for 2 months in the fall of 1999 and spring of 2000. Sea urchins from a laboratory‐cultured population of equal age, weight and test diameter were used. Apparent digestibility coefficients (ADC%) for protein and energy, using acid‐insoluble ash as a marker, were measured for all experimental diets. Apparent digestibility coefficients for protein was high (>75%) for all diets. Energy digestibility varied among the diets and was lowest for G. conferta (50–62%). The three diets contained varying digestible protein (DP) to digestible energy (DE) ratios of 25, 26 and 12 mg kJ^?1 for U. lactuca, G. conferta and the prepared diet respectively. Digestible protein intake was similar for all treatments, but DE intake was greater for sea urchins fed the prepared diet in both seasons. As a result, the gonad production was significantly higher for urchins fed the prepared diet, suggesting that energy was limiting in the algal diets. Paracentrotus lividus spawned during the spring experiment, resulting in protein loss in all treatments. Protein loss was lowest in the sea urchins fed the prepared diet. Enhanced gonadal growth and gamete development of P. lividus resulted from the higher dietary energy content of the prepared diet.