Histochemistry of gland cells of Eurytrema pancreaticum cercariae.

The cercariae of Eurytrema pancreaticum (Janson, 1889) possess four types of gland cells - proper cystogenic, penetration, ventral and dorsal gland cells. The secretion of ventral and dorsal gland cells is released into the tegument. The proper cystogenic gland cells are the largest and their contents serve for the formation of the cyst wall of metacercariae in the second intermediate host. The secretion of proper cystogenic gland cells contains besides neutral mucosubstances also acid mucosubstances with both carboxyl- and sulphogroups digestible with beta-glucuronidase. The secretion of penetration gland cells contains neutral mucosubstances and proteins with tyrosine, tryptophan and SS groups. The ventral gland cells contain mostly acid mucosubstances with sulphogroups, which are digested with beta-glucuronidase, and proteins with tyrosine, tryptophan and SH groups. The rudimentary dorsal gland cells contain a small amount of acid mucosubstances. The whole tegument of cercariae and the two main collecting canals of the excretory system exhibit a high alkaline phosphatase activity. The nerve ring and the main nerve truncs contain proteins with SH groups and hydrophilic lipids and exhibit a cholinesterase activity. The suckers contain a larger amount of glycogen.     

Fipronil modulation of GABAA receptor single-channel currents

Fipronil is the first phenylpyrazole insecticide introduced for pest control. Although fipronil is known to inhibit GABA receptors, the detailed mechanism of action remains to be seen. In order to elucidate the mechanism of fipronil interaction with the mammalian GABAA system, single-channel patch clamp experiments were performed using rat dorsal root ganglion neurons. The amplitude of main conductance state (27pS) current was not significantly altered by co-application of 10 microM fipronil and 10 microM GABA. The histograms of open time distribution were fitted to a sum of three exponential functions. After application of 10 microM fipronil, the proportion of the fastest component increased slightly and that of the slowest component decreased slightly. Thus, the mean open time was decreased from 11.4 ms to 7.8 ms by fipronil. The histograms of closed time distribution were fitted to a sum of four exponential functions. Fipronil 10 microM prolonged the slowest time constant resulting in a prolongation of the mean closed time from 29.7 ms to 52.8 ms. Thus, the frequency of channel openings was reduced. Thus, the fipronil suppression of GABA-induced whole-cell currents is caused in part by decreases in the channel open time and the frequency of channel openings.     

Visualization of the effect of a surfactant on the uptake of xenobiotics into plant foliage by confocal laser scanning microscopy

A radiolabelling method is generally used to determine the foliar uptake of xenobiotics. This technique cannot provide any information on the localization of chemicals inside leaf tissues. The influence of an alcohol ethoxylate surfactant on the uptake of three fluorescent dyes, difluorofluorescein (hydrophilic), rhodamine B (moderately lipophilic) and a naphthalimide dye (lipophilic), into the leaves of three contrasting species, bean (Vicia faba), wheat (Triticum aestivum) and cabbage (Brassica oleracea), at 16 h after treatment was measured using a conventional wash‐off method and also visualized in vivo by confocal laser scanning microscopy (CLSM). Whereas the lipophilic dyes showed greater intrinsic uptake than the hydrophilic one, the enhancing effect of the surfactant on uptake was more pronounced for the latter. CLSM revealed that the presence of the surfactant increased the transport of difluorofluorescein into the epidermal cells of bean and wheat leaves, but not cabbage leaves. Rhodamine B showed greatest transcuticular diffusion in all three species, but most of the dye moved into the vacuole of the epidermal cells. The naphthalimide dye was strongly retained by the wax–cuticle layer of all species, even in the presence of the surfactant. CLSM has proven to be an attractive tool for studying xenobiotic diffusion. The results obtained using fluorescent dyes are believed to be applicable to the foliar uptake of herbicides.     

Effectiveness of the resistance inducer prohexadione‐Ca against fireblight in shoots of apple trees inoculated with Erwinia amylovora1

Due to the lack of effective, non‐phytotoxic and publicly acceptable materials for controlling fireblight in pome fruit trees, novel strategies against Erwinia amylovora are being sought. Resistance‐inducing compounds, such as prohexadione‐Ca, represent promising alternatives. Prohexadione‐Ca is the active substance of the bioregulator Regalis, currently being introduced in several European countries and overseas. Prohexadione‐Ca reduces shoot elongation due to inhibition of gibberellin biosynthesis. Furthermore, it leads to significant changes in the spectrum of flavonoids and their phenolic precursors in pome fruits, which causes reduced susceptibility to fireblight and other pathogens. In 2002 and 2003, container‐grown apple trees of the cultivars ‘Idared’ and ‘Freedom’ were treated with different dosages of prohexadione‐Ca two weeks before inoculation with E. amylovora. The effect of prohexadione‐Ca against shoot blight was determined by measuring the lengths of necrotic lesions and symptoms on vascular bundles caused by the pathogen. Treatments with prohexadione‐Ca turned out to be much superior to the ones with streptomycin, kasugamycin and a bacterial antagonist, which were used for comparison. Acibenzolar‐S‐methyl (Bion), another resistance‐inducing compound, was included in some of the experiments and gave intermediate results. The simultaneous control of excessive shoot growth and shoot infections by fireblight is seen as a major advantage of using prohexadione‐Ca in pome fruit trees.     

Effects of farrowing system on behavior and growth performance of growing-finishing pigs

A study was conducted to compare growth performance and behaviors of group-farrowed pigs with those of confinement-farrowed pigs. A total of 216 pigs (8 wk of age) were used, with an equal number of group-farrowed or confinement-farrowed pigs from 1 farrowing batch. Group-farrowed pigs were farrowed in bedded, individual pens and mingled into a group of 8 litters at 12 (±1.3) d of age. Pigs were weaned at 33 (±1.3) d and remained in the farrowing room until 8 wk of age. Confinement-farrowed pigs were farrowed in farrowing crates. At weaning (32 ± 2.0 d of age), confinement-farrowed pigs were mixed and moved to pens of 9 pigs in a confinement nursery and remained there until 8 wk of age. At 8 wk of age, pigs from the 2 housing systems were allocated to 24 pens of 9 pigs in a confinement growing-finishing barn, with 12 pens from each of the housing systems. Within farrowing system, pigs from different groups or pens were mixed upon entering the growing-finishing barn. Individual BW was recorded at allotment (wk 0) to the growing-finishing barn and every 2 wk thereafter for 14 wk. Feed intake and G:F were monitored on a pen basis every 2 wk between wk 0 and 14 of the study period. Behaviors of pigs were video recorded in 6 pens of each housing treatment for 24 h on the day of mixing (d 0), d 7, and d 14 after mixing in the finisher barn. The video recordings were scanned at 5-min intervals to calculate behavioral time budgets for lying, standing, eating, drinking, and belly nosing. Data were analyzed using the Proc Mixed model of SAS with repeated measures. Compared with confinement-farrowed pigs, group-farrowed pigs spent more time lying (85.7 vs. 82.7%; SE = 0.75; P < 0.001) and belly nosing (0.05 vs. 0.02%; P < 0.05) and less time standing (5.8 vs. 7.5%; SE = 0.49; P < 0.01) and eating (7.3 vs. 9.3%; SE = 0.40; P < 0.001). The difference in behavioral time budgets was associated with differences in performance of pigs from the 2 housing systems. Group-farrowed pigs exhibited greater ADG (866 vs. 814 g; SE = 10.3; P < 0.01) for the initial 2 wk after mixing, less ADFI (2,004 vs. 2,188 g; SE = 42.5; P < 0.05), and improved G:F (0.431 vs. 0.393; SE = 0.0078; P < 0.01) for the entire 14-wk study period compared with confinement-farrowed pigs. These results suggest that group-farrowed pigs were more efficient than confinement-farrowed pigs in utilizing dietary energy for BW gain by lying more and standing and eating less during the growing and finishing period.     

Genetic and phenotypic relationships of serum leptin concentration with performance, efficiency of gain, and carcass merit of feedlot cattle

Leptin is the hormone product of the obese gene that is synthesized and predominantly expressed by adipocytes. This study estimated the genetic variation in serum leptin concentration and evaluated the genetic and phenotypic relationships of serum leptin concentration with performance, efficiency of gain, and carcass merit. There were 464 steers with records for serum leptin concentration, performance, and efficiency of gain and 381 steers with records for carcass traits. The analyses included a total of 813 steers, including those without phenotypic records. Phenotypic and genetic parameter estimates were obtained using SAS and ASREML, respectively. Serum leptin concentration was moderately heritable (h2 = 0.34 +/- 0.13) and averaged 13.91 (SD = 5.74) ng/mL. Sire breed differences in serum leptin concentration correlated well with breed differences in body composition. Specifically, the serum leptin concentration was 20% greater in Angus-sired steers compared with Charolais-sired steers (P < 0.001). Consequently, ultrasound backfat (27%), carcass 12th-rib fat (31%), ultrasound marbling (14%), and carcass marbling (15%) were less in Charolais- than Angus-sired steers (P < 0.001). Conversely, carcass LM area (P = 0.05) and carcass lean meat yield (P < 0.001) were greater in Charolais- compared with Angus-sired steers. Steers with greater serum leptin concentration also had greater DMI (P < 0.001), greater residual feed intake (P = 0.04), and partial efficiency of growth (P = 0.01), but did not differ in feed conversion ratio (P > 0.10). Serum leptin concentration was correlated phenotypically with ultrasound backfat (r = 0.41; P < 0.001), carcass 12th-rib fat (r = 0.42; P < 0.001), ultrasound marbling (r = 0.25; P < 0.01), carcass marbling (r = 0.28; P < 0.01), ultrasound LM area (r = -0.19; P < 0.01), carcass LM area (r = -0.17; P < 0.05), lean meat yield (r = -0.38; P < 0.001), and yield grade (r = 0.32; P < 0.001). The corresponding genetic correlations were generally greater than the phenotypic correlations and included ultrasound backfat (r = 0.76 +/- 0.19), carcass 12th-rib fat (r = 0.54 +/- 0.23), ultrasound marbling (r = 0.27 +/- 0.22), carcass marbling (r = 0.76 +/- 0.21), ultrasound LM area (r = -0.71 +/- 0.19), carcass LM area (r = -0.75 +/- 0.20), lean meat yield (r = -0.59 +/- 0.22), and yield grade (r = 0.39 +/- 0.26). Serum leptin concentration can be a valuable tool that can be incorporated into appropriate selection programs to favorably improve the carcass merit of cattle.     

Effects of the Administration of Lactobacilli,Maltodextrins and Fructooligosaccharides upon the Adhesion of <Emphasis Type="Italic">E. coli</Emphasis> O8:K88 to the Intestinal Mucosa and Organic Acid Levels in the Gut Contents of Piglets

The influence of the administration of Lactobacillus plantarum, maltodextrin Maldex 150 and Raftifeed IPX fructooligosaccharides on the inhibition of adhesion of E. coli O8:K88 to the mucosa of the jejunum, ileum and colon as well as on the organic acid levels was investigated in 33 conventional piglets. The counts of E. coli K88 adhering to the jejunal mucosa were significantly decreased (p < 0.05) in Lact. plantarum + Maldex 150 and Lact. plantarum + Maldex 150 + Raftifeed IPX groups. The counts of E. coli K88 adhering to the colonic mucosa of Lact. plantarum + Maldex 150 + Raftifeed IPX and Lact. plantarum + Raftifeed IPX groups were significantly lower (p < 0.05) than in Lact. plantarum and Lact. plantarum + Maldex 150 animals. The acetic acid levels in the ileum and colon of the Lact. plantarum + Maldex 150 + Raftifeed IPX group and Lact. plantarum + Raftifeed IPX group were significantly higher (p < 0.05) than in the Lact. plantarum and Lact. plantarum + Maldex 150 group. The combination of Lact. plantarum, maltodextrin Maldex 150 and Raftifeed IPX proved to be the most effective one to inhibit the counts of E. coli O8:K88 adhering to the intestinal mucosa of the jejunum and colon of conventional piglets.     

Effect of high-dose phytase and citric acid,alone or in combination,on growth performance of broilers given diets severely limited in available phosphorus

1. Two trials were conducted to evaluate the effect of high-dose phytase alone or in combination with citric acid (CA) in the diet severely limited in available phosphorus (P) on performance, plasma P and plasma Ca of broilers from 22 to 42 d of age.

2. In Trial 1, 297 21-d-old female chicks were placed into 27 pens and allocated to 9 maize-soybean meal-based dietary treatments, which were a positive control [PC, 4.23 g/kg non-phytate P (NPP)] and 8 negative control (NC, 1.35 g/kg NPP) groups consisting of two concentrations of CA (0 and 20 g/kg) and 4 concentrations of phytase (0, 1000, 2000 and 4000 U/kg) in a 2 × 4 factorial arrangement. In Trial 2, 192 21-d-old male chicks were placed into 24 pens and allocated to 6 wheat-canola meal-based dietary treatments, which were a PC (4.2 g/kg NPP), a NC (1.68 g/kg NPP) and 4 NC groups consisting of two concentrations of CA (0 and 20 g/kg) and two concentrations of phytase (2000 and 4000 U/kg) in a 2 × 2 factorial arrangement.

3. In both trials, birds fed on the PC had significantly higher average daily gain (ADG), average daily feed intake (ADFI), plasma P and lower feed conversion ratio (FCR) and plasma Ca than those of birds fed on the NC. CA supplementation significantly increased ADG and ADFI. There was a significant interaction between CA and phytase on plasma P where CA improved the effect of phytase on plasma P. In Trial 1, phytase addition improved ADG, ADFI, FCR and plasma Ca linearly.

4. Briefly, this research showed the interaction effect between CA and phytase on plasma P when broilers were fed on diets based on maize-soybean meal or wheat-canola meal. The results showed that CA supplementation lowered the concentration of phytase that is needed in low NPP diets to increase plasma P.     

Colloid oncotic pressure and total protein changes in horses during anesthesia fluid therapy

It is unknown whether overlapping or sequential use of nonsteroidal anti‐inflammatory (NSAIDs) results in an increased risk for gastrointestinal (GI) ulceration. The purpose of this pilot study was to evaluate the GI effects of various combinations of an injectable NSAID followed by an oral NSAID, a scenario often employed clinically for management of the pre‐ and post‐operative canine patient. Six healthy Walker hounds received four treatment regimens in a randomized, cross‐over design with a 2 week washout period between each treatment week: carprofen (4 mg kg^–1, SQ) followed by placebo (PO, q24 × 4 days); placebo (SQ) followed by deracoxib (3–4 mg kg^–1, PO, q24 × 4 days); carprofen (4 mg kg^–1, SQ) followed by carprofen (4 mg kg^–1, PO, q24 × 4 days); carprofen (4 mg kg^–1, SQ) followed by deracoxib (3–4 mg kg^–1, PO, q24 ×4 days). Weekly bloodwork (CBC, biochemistry panel, fecal evaluation, fecal occult blood) and daily clinical scoring (TPR, vomiting, diarrhea, appetite) were obtained. GI endoscopy was performed on days –2, 1, 2, 5, and 11 days post treatment of each treatment period and lesions scored using a previously reported 6‐point scale. Data was analyzed using a mixed anova for repeated measures. There were no significant differences in clinical or clinicopathologic data between groups. Within the carprofen‐carprofen and carprofen‐deracoxib groups, lesions worsened by Day 5 (1 day after last oral dose) for the fundic and antral regions (p < 0.05). Fundic, antral and lesser curvature lesions improved by Day 5 in the carprofen‐placebo group and lesser curvature lesions improved in the placebo‐deracoxib group (p < 0.05). No significant within‐group differences were noted for the esophagus, cardia or duodenum. The small number of dogs precludes general conclusions about the safety of sequential NSAID use, but these results suggest that a larger scale study is warranted.