ynergy of ethanol and a natural soporific--gamma hydroxybutyrate

gamma-Hydroxybutyrate and ethanol, as well as gamma-butyrolactone and ethanol are potentiative with respect to duration of loss of the righting reflex (sleep time). The concentration of ethanol in the liver decreases from 30 to 90 minutes after rats are injected with ethanol, but there is no change when ethanol is injected with gamma-butyrolactone. In view of the fact that gamma-hydroxybutyrate is a natural intermediate in brain, the effects of ethanol on the central nervous system may be mediated through its interaction with gamma-butyrolactone.     

The effect of perineural anesthesia on infrared thermographic images of the forelimb digits of normal horses

Infrared thermography is an imaging modality gaining popularity as a diagnostic aid in the evaluation of equine lameness. Anecdotal reports of skin hyperthermia induced by local anesthesia, detected by thermography, have been made; however, no controlled studies have been reported. The purpose of this study was to examine the effects of perineural anesthesia on infrared thermographic images of the forelimb digits in normal horses. After environmental acclimation, infrared thermographs were made at intervals of 0, 5, 10, 15, 30, and 45 min from administration of mepivacaine hydrochloride or phosphate buffered saline in 6 adult horses with no clinical evidence of abnormality of the forelimb digits. The mean limb surface temperatures were compared by 2-factor ANOVA. Results indicated no significant difference between treatments, time after injection, or an interaction of time and treatment. Infrared thermographic imaging apparently can be performed within 45 min of perineural mepivacaine hydrochloride anesthesia without risk of artifactual changes in limb surface temperature.     

The mechanism of linuron phytotoxicity in maize

The mechanism whereby Iinuron changes the functional and structural characteristics of chloroplast membranes was studied. The primary effect of the herbicide, the inhibition of phoiosynihetic electron transport results in an immuediatecessa-tion of carbon dioxide fixation and alterations in the membrane energization. These are accompanied by secondary processes contributing to phytotoxicity. The fundamental action in its phytotoxicity, as shown in a model system of isolated chloro-plasts, is the peroxidaiive breakdown of the polyunsaturated membrane lipids. This leads to destruction of the pigments, changes in the energy transfer, disorganization of the chloro-plast membranes, and accumulation of toxic organic peroxides.     

Factors affecting nutrient digestibility in rainbow trout (Oncorhynchus mykiss) fed a plant protein–based diet supplemented with microbial phytase

Factors influencing apparent digestibility coefficient (ADC) of nutrients from a plant protein–based diet supplemented with microbial phytase were investigated in a series of experiments with rainbow trout (Oncorhynchus mykiss). The influence of phytase level, water temperature, feed particle size and addition of a protease/non‐starch polysaccharidase (PNSP) enzyme cocktail were tested in a phytase‐supplemented (2000 FTU kg^?1) diet. Finally, the influence of Ca/P ratio, addition of 1,25‐hydroxycholeocalciferol, or inclusion of lactic acid (LA) in diets with and without phytase was evaluated. Addition of microbial phytase improved ADC of dry matter (DM), protein, ash and minerals (P, Ca, Mg, Fe and Zn) (P < 0.05). Reducing feed particle size potentiated the effect of phytase on P and ash ADC, as did the addition of a PNSP enzyme cocktail; the latter also significantly improved DM ADC in both control and phytase‐supplemented diets. Increasing the Ca/P ratio reduced the effect of phytase on P and ash ADC. Addition of 1,25‐dihydroxycholecalciferol and LA had no effect on DM, P and ash ADC in control diets and tended to reduce the phytase‐induced increase in P ADC.     

Utilization of soybean meal as an alternative protein source in the Mediterranean yellowtail, Seriola dumerili

The availability of defatted soybean meal as a substitute for fish meal was evaluated in juvenile (450 g on average) yellowtail fed diets containing several levels of soybean meal (from 20 to 50%). After 153 days, liveweight averages were 980, 925, 795 and 670 g for fish fed diets in which fish meal was partially substituted with 20, 30, 40 and 50% soybean meal, and feed conversion ratios were 2.79, 3.09, 4.57 and 6.52, respectively. Regression analysis showed a negative effect of inclusion of soybean, although fish fed diets containing 20% and 30% of soybean did not present statistical differences and grew significantly more, and had a better feed conversion ratio, than fish fed 40 or 50% diets. Likewise, muscle protein level was lower and lipid content was higher in fish fed 20 or 30% soybean. No differences were obtained for protein digestibility coefficients of experimental diets.     

Use of biofloc technology during the pre‐maturation period of Litopenaeus vannamei males: effect of feeds with different protein levels on the spermatophore and sperm quality

The objectives of this study were: (1) Compare two systems for pre‐maturation of Litopenaeus vannamei in terms of spermatophore and sperm quality, (2) Compare the effect of feeds with different protein levels on reproductive quality of males reared in a biofloc‐dominated system. Animals (36.40 ± 3.13 g) reared under biofloc technology (BFT) were used in the 30‐day experiment, which involved four treatments: one in a clear water system (CW) and other three in a BFT system. The BFT treatments were differentiated by feed: mix of fish, squid and crab (BFT+FF) composed of 68.48% dietary protein (DP); broodstock feed (BFT+BF) composed of 52.51% DP; and juvenile feed (BFT+JF) composed of 39.91% DP. Feed in the CW was also the mix of fresh food. Spermatophore and sperm quality were analyzed at the beginning and end of the experiment. Higher normal sperm rate was recorded in the CW compared with the BFT+FF. Among the BFT treatments, the BFT+FF had the lowest normal sperm rate. Thus, the use of BFT for pre‐maturation of L. vannamei allowed the reduction in dietary protein levels from 68.48% (BFT+FF) to 39.91% (BFT+JF) and the maintenance of spermatophore and sperm quality compared to the system based on high daily exchange rate.     

放线菌Act1对连作西瓜枯萎病的防治效果

为了探索放线菌制剂Act1对连作西瓜枯萎病的防治效果及其对西瓜根际微生物含量的影响,采用大棚小区田间试验,以不接种放线菌制剂Act1为对照,以播种期接种和定植期接种为处理,研究不同处理对西瓜生长、枯萎病发生及其根域微生态的影响。结果表明:接种放线菌制剂的处理均能显著降低连作西瓜枯萎病的发生率,其中育苗期接种防效最显著,达到52.17%;育苗期接种放线菌制剂Act1显著促进了植株的生长;并增加了西瓜根区细菌和放线菌的数量,降低了真菌的数量且A/F、A/B、B/F与对照相比分别增加了1.38～5.5、1.53～5.25、1.29～1.75倍。接种放线菌制剂Act1的处理均能显著防治连作西瓜枯萎病的发生并改善根际微生物的组成。