Root turnover and root necromass accumulation of Norway spruce (Picea abies) are affected by soil acidity

Fine root distribution and turnover were investigated in ca. 40-year-old pure Norway spruce (Picea abies Karst.) stands in Germany, growing on four sites that differed in soil acidity (Eberg?tzen < Barbis < Fichtelgebirge = Harz). The density of fine root biomass and necromass in different soil horizons differed among the sites. At one of the most acidic sites (Harz), fine root density in the humus layer was more than twice that at the least acidic site (Eberg?tzen). At the two most acidic sites, Fichtelgebirge and Harz, the ratio of biomass to necromass was significantly lower than at Eberg?tzen and Barbis, particularly in the subsoil layer. In each stand, clear vertical gradients in fine root length density and root tip density were observed. Most of the roots and the root tips were in the humus layer and in the first mineral soil horizon (0-10 cm). There was a significantly different decrease in specific root length (cm gDM (-1)) and specific root tip density (root tips gDM (-1)) in the more acidified stands Fichtelgebirge and Harz compared with Eberg?tzen and Barbis. Fine root production estimated by ingrowth cores and a net method was approximately twice as high in the more acidic stands Fichtelgebirge and Harz compared with Eberg?tzen and Barbis. Rates of living fine root biomass turnover were higher at the Fichtelgebirge and Harz sites than at the Eberg?tzen site. Rates of necromass turnover were similar at all sites. The results suggest that the accumulation of necromass was not due to a slower disappearance at the more acid sites, but to earlier root death. Roots contributed 46% to root + needle litter and 32% to root + total aboveground litter at the Harz site in 1997.     

Motor responses to stimulation during isoflurane anaesthesia in pigs

Objective To investigate motor responses to stimulation during the transition from ‘deep’ (burst suppression) to ‘light’ isoflurane anaesthesia in pigs. Study design Prospective, randomized observational study. Animals Five castrated male and five female Norwegian landrace pigs, weighing 19–29 kg. Materials and methods Anaesthesia was induced with isoflurane and the inspired concentration gradually increased until a burst suppression electroencephalogram (EEG) was recorded. End‐tidal isoflurane concentration ( F ) was then allowed to equilibrate for 30 minutes after which the eyelashes, cornea, nasal septum, anus, interdigital skin fold, periople, tail and claw were stimulated. The motor response to stimulation at each location was graded from 0 to 5. End‐tidal isoflurane concentration was decreased 0.3% and the areas re‐stimulated; this was repeated three times in each pig. A linear regression analysis using response as dependent and anaesthetic level as independent variable was performed for each stimulus in each pig. Using Student's t‐statistic a 95% confidence interval for the mean slope of each stimulus was constructed. Results No pig responded to eyelash brushing. The mean slopes for the other stimuli indicated increasing responses with decreasing F . Responses to periople pinching and tail and claw clamping showed significant increases. No stimuli consistently increased the magnitude of response in all pigs, and the appearance and absence of a response was inconsistent between pigs. Motor responses occurred in at least one pig during isoflurane burst suppression anaesthesia to all stimuli except eyelash brushing. Conclusions All the stimuli investigated may elicit movement responses during burst suppression anaesthesia with isoflurane except eyelash brushing. No consistent response pattern between pigs was observed with decreasing isoflurane concentration. Of the stimuli evaluated, clamping the tail or claw and pinching the periople appear the most reliable indicators of anaesthetic depth. Clinical relevance The absence or presence of single reflexes does not accurately reflect the degree of isoflurane‐induced cortical depression in individual pigs.     

猪增生性肠炎与育肥猪的腹泻问题

消化道疾病往往导致养猪生产中相当大的经济损失,尽管最初的症状只是粪便黏稠不成形.一方面可能是致病性因素改变了猪消化道环境,使机体变得虚弱;另一方面,当育成猪受到腹泻影响时,应该考虑到还有很多可能的原因.     

Analysis of systematic and genetic effects on the prevalence of different types of primary lens opacifications in the wild-boar-colored wirehaired Dachshund

The aims of this study were to analyze the influence of systematic environmental effects on the prevalence of primary non-congenital cataract (CAT), fibreglass cataract in the nucleus (FCN), and prominent suture lines (PSL) and to estimate the heritabilities of these eye diseases in the wild-boar-colored wirehaired Dachshunds (WWD) bred in the German Dachshund Club 1888 e.V. (DTK). Data included 2,430 WWD born between 1995 and 2003 that were examined between 1996 and 2005 by veterinary ophthalmologists. CAT was diagnosed in 3.83% of the 2,430 dogs, FCN in 3.74%, and PSL in 2.76%. Sex, size, inbreeding coefficient, the age of the dog at examination, experience of the veterinary ophthalmologist and the additive genetic effect of the animal were considered in the multivariate linear model. The age of the dog at examination had a significant influence on the prevalence of FCN. The degree of experience of the veterinary ophthalmologist significantly influenced the prevalence of FCN and PSL. Using a transformation into the Dempster-Lerner threshold model, heritability estimates (h(DL)2) for WWD were h(DL)2 = 0.39 +/- 0.13 for CAT, h(DL)2 = 0.36 +/- 0.11 for FCN and h(DL)2 = 0.49 +/- 0.12 for PSL. Positive genetic correlations (r(g)) were found between CAT and FCN (r(g) = 0.58 +/- 0.21), between PSL and FCN (r(g) = 0.83 +/- 0.23), and between CAT and PSL (r(g) = 0.79 +/- 0.06). The eye diseases investigated here in the Dachshund were found to be genetically influenced and positively correlated traits.     

Gastrointestinal stromal tumour and hypoglycemia in a Fjord pony: Case report

Background

Neoplasia may cause hypoglycemia in different species including the horse, but hypoglycemia has not previously been reported in the horse associated with gastrointestinal stromal tumours.

Case presentation

A case of a gastrointestinal stromal tumour in a Fjord pony with severe recurrent hypoglycemia is presented. The mechanism causing the hypoglycemia was not established.

Conclusion

This case indicates that a gastrointestinal stromal tumour may cause hypoglycemia also in the horse.     

Clinical signs and diagnosis of thiamine deficiency in juvenile goshawks (Accipiter gentilis)

Between 2002 and 2006, a large number of juvenile northern goshawks (Accipiter gentilis) with central nervous signs were examined. They were aged between 45 and 55 days and had been fed on frozen and thawed day-old chicks. High-performance liquid chromatography showed that the birds had whole blood thiamine levels between 2.2 and 6.0 microg/l; the concentrations of other blood constituents were within their reference ranges. Treatment with thiamine hydrochloride rapidly resolved the clinical signs. Measurements of the concentration of thiamine in 22 free-ranging and captive goshawks showed that they ranged from 45.1 to 200 microg/l.     

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Organophosphorothioates and synergised synthetic pyrethroids as grain protectants on bulk wheat

Organophosphorothioates and synergised synthetic pyrethroids were used in duplicate field trials carried out on bulk wheat in commercial silos in Queensland and New South Wales. Laboratory bioassays using malathion-resistant strains of insects were carried out on samples of treated grain at intervals over 9 months. These established that all treatments were generally effective. Deltamethrin (2 mg kg^?1)+ piperonyl butoxide (8 mg kg^?1), fenitrothion (12 mg kg^?1)+ fenvalerate (1 mg kg^?1)+ piperonyl butoxide (8 mg kg^?1), fenitrothion (12 mg kg^?1)+ phenothrin (2 mg kg^?1)+ piperonyl butoxide (8 mg kg^?1) and pirimiphos-methyl (4 mg kg^?1)+ permethrin (1 mg kg^?1)+ piperonyl butoxide (8 mg kg^?1) controlled common field strains of Sitophilus oryzae (L.) and Rhyzopertha dominica (F.). Against a highly resistant strain of S. oryzae, deltamethrin (2 mg kg^?1)+ piperonyl butoxide (8 mg kg^?1) was superior to the remaining treatments. All treatment combinations completely prevented progeny production in Tribolium castaneum (Herbst), T. confusum Jacquelin du Val and in Ephestia cautella (Walker). Residues of deltamethrin, fenvalerate, permethrin and phenothrin were determined and shown to be highly persistent on stored wheat. During milling, residues accumulated in the bran fractions and were reduced in white flour. They were not significantly reduced during baking.     

Antibacterial spectrum and some other characteristics of an antimicrobial factor produced by Yersinia ruckeri

Yersinia ruckeri produces an antibacterial factor which inhibits the growth of a wide spectrum of Gram-negative and Gram-positive bacteria, though not other strains of Y. ruckeri. The antibacterial factor was produced at low temperatures (4-20 degrees C), but not at 37 degrees C. The activity was lost after treatment of the supernatant with chloroform, UV-light and after boiling of the supernatant. One did not succeed in obtaining the antibacterial factor in a sterile solution.     

Bovine monoclonal antibody specific for Brucella abortus lipopolysaccharide

The development of a bovine monoclonal antibody against Brucella abortus smooth lipopolysaccharide (BM-8) by interspecies fusion of bovine peripheral lymphocytes from an immunized cow and a murine plasmacytoma cell line is described. The twice cloned cell line secreted bovine IgG1 subclass antibody. Ascites fluid was prepared in pristane treated nu/nu mice by intraperitoneal injection. The pooled ascites fluid was purified by affinity chromatography and the functions of the antibody assessed in various serological tests. The BM-8 antibody did not agglutinate well at a neutral pH, however, under acid conditions it was efficient at agglutinating B. abortus cells. The antibody did not precipitate B. abortus LPS in double agar gel immunodiffusion but was very active in the direct complement fixation test and the indirect enzyme immunoassay, although it was unable to compete with a murine monoclonal antibody in a competitive enzyme immunoassay.