Interaction of ionophore and vitamin E in knockdown syndrome of turkeys

Monensin and vitamin E concentrations, as well as histopathology of skeletal muscles and myocardium, were evaluated in broad-breasted white turkeys kept in commercial facilities. Turkeys with knockdown syndrome had myopathy of skeletal muscles, but no lesions in the myocardium. Generally, concentration of monensin in serum was highest in turkeys diagnosed with knockdown syndrome given more than 90 mg/kg of monensin in the diet, followed by turkeys diagnosed with knockdown syndrome given <90 mg/kg of monensin in the diet, healthy turkeys fed a diet that contained <90 mg/kg of monensin, and finally healthy turkeys fed a diet free of monensin (not detectable). However, the concentration of monensin was highly variable within each group, and the median was lower than the average. Vitamin E concentrations in the livers varied from low-normal to below normal and were statistically higher in healthy turkeys fed a diet free of monensin than in the livers of birds from the 3 groups exposed to monensin. This suggests that the concentration of monensin in serum positively correlates to the severity of clinical signs and pathology and to the amount of monensin in the feed. Although the methodology developed to detect serum monensin concentrations is beneficial and accurate for case investigations, it is recommended that several samples from each flock be evaluated because of variation within a flock. The current study also suggests that monensin in the feed could induce lower concentrations of vitamin E in the liver of turkeys and can predispose the turkeys to knockdown syndrome.     

Thermal contrast in the atmosphere of venus: initial appraisal from pioneer venus probe data

The altitude profiles of temperature and pressure measured during the descent of the four Pioneer Venus probes show small contrast below the clouds but significant differences within the clouds at altitudes from 45 to 61 kilometers. At 60 kilometers, the probe which entered at 59.3 degrees north latitude sensed temperatures 25 K below those of the lower latitude probes, and a sizable difference persisted down to and slightly below the cloud base. It also sensed pressure below those of the other probes by as much as 49 millibars at a mean pressure of 200 millibars. The measured pressure differences are consistent with cyclostrophic balance of zonal winds ranging from 130 +/- 20 meters per second at 60 kilometers to 60 +/- 17 meters per second at 40 kilometers, with evidence in addition of a nonaxisymmetric component of the winds. The clouds were found to be 10 to 20 K warmer than the extended profiles of the lower atmosphere, and the middle cloud is convectively unstable. Both phenomena are attributed to the absorption of thermal radiation from below. Above the clouds, in the lower stratosphere, the lapse rate decreases abruptly to 3.5 K per kilometer, and a superimposed wave is evident. At 100 kilometers, the temperature is minimum, with a mean value of about 170 K.     

A simple passive sampler for measuring ammonia emission in the field

A new type of passive sampler for the determination of NH₃ emission from land surfaces and manure storages was tested in a micrometereological mass balance method. The sampler consists of 2 glass tubes, each with a length of 10 cm and an internal diameter of 0.7 cm. The two glass tubes are connected in series, with one end fitted with a thin stainless steel disc having a 1 mm hole in the center. The inner surface of each glass tube is coated with oxalic acid. The results show that the passive flux sampler can be used to give accurate determinations of NH₃ emission. The passive flux sampler makes gas washing bottles, pumps, flow meters, anemometers, and electricity unnecessary and ammonia loss can be determined easily and cheaply without the requirement of a large labor force.     

Studies on uptake and intracellular processing of infectious pancreatic necrosis virus by Atlantic cod scavenger endothelial cells

Previous work in our group has identified the scavenger endothelial cells (SECs) of heart endocardium in cod, Gadus morhua L., as the major site for elimination of both physiological and foreign macromolecular waste from the circulation. The present study was undertaken to establish the role of cod SECs in the clearance of virus. We focused on infectious pancreatic necrosis virus (IPNV) as it is a well-known virus with a broad host range, and causes significant economic losses in the salmon industry. Our results showed that cod SEC cultures infected by the IPNV produce high titres of new virus. Ligand-receptor inhibition experiments suggested that the virus did not enter the cells through any of the major endocytosis receptors of cod SECs. Yet, the infection lowered the capacity of the cells to endocytose ligands via the scavenger receptor. Inhibitors of receptor recycling and vesicle acidification did not affect virus infectivity. The finding that SEC cultures prepared from 25% of the cod produced high titres of IPNV without being infected in the laboratory, suggests that SECs of cod may serve as reservoirs for IPNV in persistently infected cod.     

Operator assessment of tractor roll angle with and without a tractor stability visual feedback device

According to a 2004 National Institute for Occupational Safety and Health (NIOSH) report, approximately 250 to 350 fatalities occur each year due to incidents involving production agriculture workers and tractors. Tractor overturns account for about 150 to 200 of these deaths. The goals of this project were to study operators' understanding of tractor roll angles and test a device to effectively deliver stability information to the tractor operator. This project required the design and construction of a full-scale tractor cab roll simulator that was used to identify lateral roll angles at which volunteer participants felt uncomfortable, as well as lateral roll angles at which they would no longer operate a tractor. In addition, the participants performed a series of tasks to test the functionality of a visual slope indicator that was designed to help them estimate slope angles. The project tested 231 tractor operators' perceptions of safe operation on side slopes and 128 participants' interactions with the visual slope indicator. Testing showed that the visual slope indicator was able to influence the angle estimations of the novice tractor operator population and helped the entire population of participants more accurately rank the simulator scenarios.     

Biological P cycling is influenced by the form of P fertilizer in an Oxisol

Phosphate rock (PR) is an alternative fertilizer to increase the P content of P-deficient weathered soils. We evaluated the effects of fertilizer form on indicators of biological cycling of P using an on-farm trial on a Rhodic Kandiudox in western Kenya. Treatment plots were sampled after 13 cropping seasons of P applications as Minjingu phosphate rock (PR) or as triple super phosphate (?TSP) (50 kg P ha^?1 season^?1), as well as a P-unfertilized control (0 kg P ha^?1 season^?1). Soils (0–15 and 15–30 cm) were analyzed for microbial biomass P (P_mic), activities of acid phosphomonoesterase, alkaline phosphomonoesterase, and phosphodiesterase, and sequentially extractable P fractions. P additions as Minjingu PR yielded 299% greater P_mic than TSP at 0–15-cm depth despite similar labile P concentrations in the two P fertilization treatments and stimulated activities of acid phosphomonoesterase (+39%). When added in the soluble form of TSP, a greater percentage of total soil P was present in mineral-bound forms (+33% Fe- and Al-associated P). Higher soil pH under Minjingu PR (pH 5.35) versus TSP (pH 5.02) and the P-unfertilized treatment (pH 4.69) at 0–15-cm depth reflected a liming effect of Minjingu PR. The form of P fertilizer can influence biological P cycling in weathered soils, potentially improving P availability under Minjingu PR relative to TSP via enhanced microbial biomass P and enzymatic drivers of P cycling.     

Determination of Total Ammonium Nitrogen in Pig and Cattle Slurry: Sample Preparation and Analysis

Abstract

In order to supply the correct amount of ammonium to the crop when slurry is spread on the field, it is necessary to know the ammonium concentration. Slurry is a heterogeneous substance and there is a risk that organic N-compounds and the ionic strength will interfere with the determination of ammonium. The usability of five different methods for the determination of ammonium in solution has been tested on 18 different cattle and pig slurries and compared to a manual distillation titration technique. Colorimetric determination using an autoanalyzer and an automatic titration distillation device using MgO were highly accurate, and the precision was close to 1%. Distillation with NaOH caused interference from hydrolysable organic compounds. An ammonium electrode could be used, but the accuracy was not good. When using the automatic titration distillation device, samples should immediately be transferred to Kjeldahl flasks with water or acidified to prevent loss of volatile ammonia, unless they are to be distilled within 30 min.     

The nitrogen metabolism in the large intestine of ruminants. 8. Metabolism of intracecally infused 15N-urea with a supplement of pectin in heifers]

Three heifers with live weights of 255, 261 and 300 kg were supplied with ileo-caecal re-entrant cannulas, jugular vena catheters and bladder catheters. The ration consisted of 4 kg maize silage and 4 kg wheat straw pellets. In a previous period 50% of the digesta flow was collected over 12 h/d on 5 consecutive days and stored in a deep-freeze. During the main period the re-entrant cannulas were disrupted and the flowing digesta was quantitatively collected. Precollected digesta and pectin were infused into the distal part of cannula hourly for about 30 hours. During the first 24 hours the digesta was also supplemented with 15N-labelled urea. The amount of pectin corresponded to about 10% of digesta dry mater. An analysis of urine, faeces, digesta and blood plasma were carried out. The application of pectin increased the 15N-incorporation in the bacterial protein of faeces from 4.7% (without supplementation in an earlier experiment) to 10.5% of the introduced 15N. The ammonia-fraction of faeces was markedly higher than the bacterial fraction. The 15N-utilization of urea by the microbes of large intestine was lower in the actual trial evident than with supplementation of starch in the anterior experiment. During the pectin administration the amount of urine increased in comparison with earlier experiments and according to the literature to about the 4.5 fold. The amount of passage of 15N at the ileum cannula (recycled 15N) was 3.8% of the 15N intake. It is the same amount as in experiments in which starch was applied.     

Apoptosis of Granulosa Cells: A Review on the Role of MAPK-signalling modules

Recent studies suggest that ovarian follicular atresia is associated with DNA fragmentation and degeneration of granulosa cells, the hallmark of programmed cell death or apoptosis. Apoptosis of granulosa cells play a major role in follicular atresia. These studies have also demonstrated the involvement of tumour suppressors, apoptotic proteins and survival factors. These factors contribute to the developmental decision as to whether the ovarian follicles mature or undergo atresia. However, the precise temporal and molecular events involved in the apoptotic pathways in this process need to be elucidated. The present report summarizes the role of Jun N‐terminal kinase (JNK), p38 mitogen activated protein kinase (p38 MAPK), and extracellular‐signal regulated kinase (ERK)‐signalling module in the regulation of pro‐ and anti‐apoptotic factors of the granulosa cells in regulating follicular atresia. The findings presented here suggest that the loss of tropic hormone support is translated into the attenuation of Raf‐1‐MAPK/ERK kinase (MEK)‐ERK‐signalling pathway of the granulosa cells and this results in the decreased phosphorylation of the pro‐apoptotic BAD.