Development of the digestive system in dusky kob,Argyrosomus japonicus,larvae

In order to contribute to the development of larval rearing technologies of dusky kob, Argyrosomus japonicus, we studied the morphology and histology of the larval digestive system from hatching to 30 days after hatch. At hatch, the digestive tract appeared as a simple tube. The mouth was closed (endogenous feeding) and it opened by 65 degree days (DD). Supranuclear vacuoles appeared by 88 DD, initiating exogenous feeding. By 145 DD, the oil globule had disappeared. The stomach, intestine, rectum and gastric glands were visible by 224 DD. Number and size of supranuclear vacuoles began to decrease with progressive vacuolisation of the enterocytes and intestinal folds became obvious. The rectum was well differentiated at 338 DD but lacked supranuclear vacuoles in the enterocytes, suggesting limited nutrient absorption. At this stage, lipid absorption shifted to the hindgut, which now contained many lipid vacuoles. Goblet cells were visible in the midgut as gastric glands appeared, and their number increased from 292 DD. At the start of the third developmental phase, the larvae had a fully functional digestive system.     

Multiyear greenhouse gas flux measurements on a temperate fen soil used for cropland or grassland

To date there is still a lack of reliable data on greenhouse gas emissions from drained fens needed to determine the climatic relevance of land use and land use change on peatlands and to supply the National Inventory Report for the German Greenhouse Gas Inventory. In this study we present the results of monthly‐based multiyear measurements of CO₂, N₂O and CH₄ flux rates in two drained agriculturally used fen ecosystems in NW Germany (cropland and grassland) over a period of 4.5 y using transparent and opaque closed chambers. CO₂ exchange was modelled at high resolution with temperature and photosynthetic active radiation. The measured and modelled values fit very well (R² ≥ 0.93). Annual GHG and Global Warming Potential (GWP) balances were determined. Net CO₂ emissions at the cropland and grassland sites were similarly high, taking into account changes in management; net ecosystem C balance amounted to about 4.0 to 5.0 Mg C ha^?1 y^?1. Emissions of N₂O and CH₄ were low at both sites. The mean GWP balance for a time frame of 100 y (GWP100) amounted to about 17.0 to 19.0 Mg CO₂‐eq. ha^?1 y^?1. The unexpectedly low greenhouse gas emissions from the cropland site are attributed to the high water table and a change in crop management. The change from corn for silage to corn‐cob mix lead transiently to rather small greenhouse gas emissions. The study confirms the need for multiyear measurements taking climatic and management variation into account.     

Color and albedo heterogeneity of Vesta from Dawn

Multispectral images (0.44 to 0.98 μm) of asteroid (4) Vesta obtained by the Dawn Framing Cameras reveal global color variations that uncover and help understand the north-south hemispherical dichotomy. The signature of deep lithologies excavated during the formation of the Rheasilvia basin on the south pole has been preserved on the surface. Color variations (band depth, spectral slope, and eucrite-diogenite abundance) clearly correlate with distinct compositional units. Vesta displays the greatest variation of geometric albedo (0.10 to 0.67) of any asteroid yet observed. Four distinct color units are recognized that chronicle processes--including impact excavation, mass wasting, and space weathering--that shaped the asteroid's surface. Vesta's color and photometric diversity are indicative of its status as a preserved, differentiated protoplanet.     

Right ventricular rupture after lateral thoracotomy for removal of rib-associated telangiectatic osteosarcoma in a dog

Objective – To describe a case of a focal right ventricular rupture following removal of a rib-associated telangiectatic osteosarcoma (TOS) in a dog.
Case Summary – A 2-year-old spayed female mixed-breed dog, weighing 20 kg, was presented in compensated hypovolemic shock due to active bleeding into the thoracic cavity. The dog was stabilized with appropriate fluid administration. Subsequent computed tomographic examination revealed a large mineralized mass originating from the body of a rib and displacing the heart. Two days after surgical removal of this mass, focal right ventricular rupture occurred and the dog died. The mass was later identified as a TOS.
New or Unique Information Provided – Although hemothorax secondary to TOS has been described previously, this report describes for the first time, spontaneous focal right ventricular rupture as a rare complication of thoracotomy and rib resection for the removal of a rib-associated, intrathoracic TOS.     

Coccidial infections in housed lambs: oocyst excretion, antibody levels and genetic influences on the infection

Faecal Eimeria oocyst excretion, body weights, humoral antibodies against E. ovinoidalis sporozoite antigen and related heritabilities were determined in housed Merinoland sheep lambs throughout a period of 100 days after birth in Germany. Altogether 10-11 Eimeria spp. were found. Cumulative incidences of E. ovinoidalis and E. weybridgensis/crandallis increased rapidly resulting in almost 100% incidence in 8 weeks old lambs. In the other species, the cumulative incidence increased more continuously. Except for E. granulosa oocysts of all species had been excreted at last once until day 30. By far the highest oocyst counts (OpG) were observed with E. ovinoidalis, followed by E. weybridgensis/crandallis. High counts were limited to the period of 5-8 weeks after birth. In the other Eimeria species oocyst counts persisted at comparatively low levels until the end of the observation period although their proportion of the total counts increased with age of the lambs. Time courses of oocyst excretion suggest an early onset of effective immunity to the major Eimeria spp., which differed for the minor species. Mean and maximum oocyst counts and body weights of the lambs were inversely correlated suggesting negative effects of the infection on the lamb's performance. High mean antibody levels on day 7 after birth dropped until day 40 and increased subsequently again. There were no indications that maternal antibodies were protective. Antibody levels on day 40 after birth were positively correlated with oocyst counts in the faeces whereas those determined on day 80 were independent of infection parameters. Heritabilities of log(10)OpG were not significantly different from 0 up to an age of 60 days. Later estimated values were between 0.54 and 0.79 suggesting that immune protective effects rather than innate effects determining disease susceptibility are under genetic influence.     

Effect of Dwarf (dw) and Frizzle (F) Genes on the Performance of Layers under Senegalese Conditions

The influence of sex-linked dwarf (dw) and incompletely dominant frizzle (F) genes on growth, egg production and quality were investigated. The experimental stock comprised 100 chicks of four genotypes: normal feathered, normal size (ffDw); normal feathered, dwarf (ffdw); frizzle, normal size (FfDw); and frizzle, dwarf (Ffdw). The dwarf gene reduced the body weight, shank length, feed intake, egg production and egg weight. The frizzle gene also reduced most of these traits, except for egg production, the interaction between the two genes being positive only for growth traits and egg number. Neither of the two genes significantly influenced egg quality. It was concluded that the dwarf gene may have some practical interest in tropical environments, while more needs to be known about the frizzle gene. This revised version was published online in July 2006 with corrections to the Cover Date.     

A simulation of Johne's disease control

A dynamic and stochastic simulation model (the "JohneSSim model") was developed to evaluate the economic and epidemiological effects of different strategies for control of paratuberculosis in dairy herds. Animals occupy one of the six defined infection states; the spread of Johne's disease is modeled with five infection routes. Many different dairy farm situations can be simulated. Control strategies that can be simulated are: (1) test-and-cull; (2) calf hygiene management; (3) vaccination and (4) grouping of animals. Losses are caused by: (1) reduced milk production; (2) diagnosis and treatment costs; (3) lower slaughter value of cows and (4) sub-optimal culling. The benefits were calculated as reduction in the losses caused by Johne's disease; the costs of each strategy were calculated on the basis of actual costs of each item; and net present value (NPV) was calculated as benefits minus costs. Herd and prevalence data from The Netherlands and Pennsylvania, USA were used. In both situations, a low true mean prevalence within 20 years could be reached only when all calf management tools were applied. The Dutch control program (PPN) was on average economically attractive (with or without labor costs, the average NPV was Euro 1183 and 12,397, respectively). In Pennsylvania, contract heifer rearing and improved calf hygiene reduced the prevalence effectively and had large economic benefits (US$ 43,917 for 20-year period) if the calves were sent to the heifer facility while very young. Validation with data from 21 infected Dutch dairy farms (as well as face-validation: comparison of the results of the JohneSSim model with experiences of Johne's experts) supported the basic assumptions in the model.     

Some biochemical parameters for qualification of bull semen

Summary Since the macroscopical and microscopical examination of bull semen does not in all cases appear to give conclusive indications concerning the fertilizing capacity, an investigation of some biochemical parameters was undertaken. It was shown that the following biochemical examination could furnish some more information about the quality of the semen: 1. Determination of the phenylalanine- α-ketoglutarate transaminase activity both in the seminal plasma and in the whole semen. A high transaminase activity in the plasma points to leakage out of the spermatozoa, thus indicating an affection of the spermatozoa. In that case larger amounts of basic amino acids and of leucine were often found in the seminal plasma than would normally be observed. 2. Gas chromatographic examination of the steroids occurring both in the seminal plasma and in the spermatozoa. In a number of infertile bulls small peaks of progesterone were found together with those of other, unidentified compounds. 3. Investigation of the carbohydrate metabolism in the semen. In a number of fertile bulls the following deviations were found: a. the presence of quite a lot of fructose in the spermatozoa; b. the presence of glucuronic acid and / of other foreign compounds in the spermatozoa or in the plasma; c. an elevated pH in the seminal plasma some 2 to 3 hours after ejaculation; d. a low phenylalanine-α -ketoglutarate transaminase activity in the whole semen (the spermatozoa had been disrupted by freezing). 4. Investigation of the presence of reducing aldehydes (glycolaldehyde and glyceraldehyde) inside the spermatozoa. The determinations mentioned under 1, 3c and 3d can easily be carried out in the laboratories of each District Animal Health Service and of the A.I. stations; the same is true of the occurrence of amino acids in the seminal plasma and of fructose and aldehydes inside the spermatozoa if facilities are available for electrophoresis and chromatography.