Modelling dairy cattle feeding in the South-East region of Brazil

Computer modelling techniques were applied to study the structure of traditional dairy farms in the South-East region of Brazil and to help define research priorities and policies. Animal feeding is considered the principal factor affecting dairy cattle performance in the study. Knowledge of animal nutrition and feed supply from Brazilian and other literature was synthesized in two mathematical models. One model deals with the optimization of resources used in supplementary feeding for dairy cows under grazing; the other predicts dairy cow performance under a range of feeding conditions imposed by changes in the level of supplementation, stocking rate and calving date. Both models are empirical in nature. The modelling approach shows itself to be a useful means of defining research priorities and making recommendations on practical aspects of dairy cow feeding and management.     

Soft tissue sarcomas and mast cell tumours in dogs; clinical behaviour and response to surgery

OBJECTIVE: To characterise the types of canine soft tissue sarcoma and mast cell tumour treated surgically at the University Veterinary Centre, Sydney. To evaluate the success of surgical treatment of these tumours and identify variables predictive of local recurrence and survival. To establish whether conclusions drawn from previous international studies are applicable to the University Veterinary Centre, Sydney, dog population and vice versa. DESIGN: Clinical presentation and results of surgical excision of 54 soft tissue sarcomas and 70 mast cell tumours affecting the trunk and limbs of dogs at the University Veterinary Centre, Sydney, between 1989 and 2001 were reviewed retrospectively. RESULTS: Cross-bred dogs and Rhodesian Ridgebacks were at significantly greater risk of developing soft tissue sarcomas, and Boxers, Australian Cattle Dogs and Staffordshire Bull Terriers were at significantly greater risk of developing mast cell tumours than other breeds. Fine needle aspiration biopsy yielded a correct diagnosis in 62.5% of soft tissue sarcomas and 96% of mast cell tumours. Local recurrence was encountered after surgical excision in 7.4% of soft tissue sarcomas and 7.3% of mast cell tumours. Metastasis occurred in 6% of soft tissue sarcomas and 12% of mast cell tumours. The most significant risk factors for local recurrence were contaminated surgical margins (soft tissue sarcomas) and histological grade (mast cell tumours). Due to the low number of animals experiencing metastasis, no conclusions could be drawn about significant risk factors. CONCLUSIONS: Aggressive surgical management of soft tissue sarcomas and mast cell tumours is associated with a low incidence of local recurrence. The type, location and behaviour of mast cell tumours and soft tissue sarcomas in the population of dogs presented to the University Veterinary Centre, Sydney are similar to those reported by others.     

A dynamic model of N metabolism in the lactating dairy cow and an assessment of impact of N excretion on the environment

Improving N utilization in dairy cows and especially reducing N output in excreta is desirable due to global concerns of agricultural contribution of N to environmental pollution, particularly as ammonia. Data from five N balance experiments were used to develop a dynamic model that was evaluated with independent data. Model predictions of feces, urine, and milk outputs were close to observed values. Statistical analysis showed that 96% of mean square prediction error for feces and urine N output predictions was due to random variation. However, the model tends to overpredict milk N output, especially at higher N intake levels. Evaluation of model predictions for independent experimental observations from Agricultural Development Advisory Service at Bridgets (U.K.) showed good agreement between predicted and observed urine N output (95% due to random variation). However, there was a slight underprediction for fecal N output (14% mean square prediction error due to bias) and overprediction of milk N output (22% of mean square prediction error due to bias). The model predictions of N outputs in excreta were sensitive to changes in energy concentration of the diet. Dietary protein degradability had only a small influence on predicted fecal N output. However, the model was sensitive in its predictions of urine N when protein degradability was varied. Application of the model to assess reduction in ammonia emissions from dairy cows showed that increasing the energy concentration could potentially reduce ammonia emissions by up to 25% per cow. Similarly, reducing CP concentration in the diet to about 16% could reduce ammonia production by 20% and lower degradability of CP to match microbial requirement by 19% per cow. The model is a first step toward a mechanistic approach of nutrient modeling, and it is a valuable method for predicting N excretions and estimating N emissions from dairy systems.     

Early hepatic immune response in rats infected with Fasciola hepatica

We investigated the phenotype of the T cells (CD4+ and CD8+) that produced Th1 (IFN-gamma) and Th2 cytokines (IL-4 and IL-10) during the firsttwo weeks of experimental fasciolosis in rats. We also followed the kinetics of the cytokine and proliferative responses of hepatic mononuclear cells (HMNC) over the same period. We found that HMNC were more numerous in the infected animals than in the controls. The percentage of CD4+ cells increased significantly after infection, whereas the percentage of CD8+ cells did not change. Moreover, the frequency of the cells producing (CP) cytokine changed after infection. The frequency of CP IFN-gamma on 7 days postinfection (pi) was similar to that in control animals. However, the frequency of CP IFN-gamma was clearly lower on day 14 pi, whereas the frequency of CP IL-4 and CP IL-10 had increased. The CP IL-10-were mostly CD4+. Mitogenic stimulation (phorbol myristate acetate/ionomycin) of HMNC led to an increase in the amounts of the Th2 cytokines in the supernatant on days 7 and 14 pi, with the increase more pronounced on day 14. In contrast, IFN-gamma levels also increased by day 7 pi but then decreased to below control levels by day 14. In addition, HMNC proliferation in response to mitogen followed a similar pattern to IFN-gamma production. These findings suggested that, during the first 2 weeks of infection, F hepatica induced a transient ThO cytokine profile followed by downregulation of the cellular response and the induction of a Th2 cytokine profile.     

Three-dimensional kinematics of the equine interphalangeal joints: articular impact of asymmetric bearing

The objective of this study was to assess the effects of asymmetric placement of the foot on the three-dimensional motions of the interphalangeal joints. Four isolated forelimbs were used. Trihedrons, made of three axes fitted with reflective markers, were screwed into each phalanx. They allowed to establish a local frame associated with each bone and thus to define the spatial orientation of the phalanges. The limbs were then placed under a power press, and subjected to compression with gradually increasing force (from 500 to 6 000 N). The procedure was performed in neutral position and with the lateral or medial part of the foot raised by a 12 degrees wedge. Flexion, collateromotion (passive abduction/adduction) and axial rotation of the interphalangeal joints were measured using a cardan angle decomposition according to the principle of the "Joint Coordinate System" described by Grood and Suntay. Raising the lateral or medial part of the hoof induced collateromotion (about 5.6 degrees +/- 0.8) and axial rotation (about 6.5 degrees +/- 0.5) of the distal interphalangeal joint. The proximal interphalangeal joint underwent axial rotation (about 4.7 degrees +/- 0.5 at 6 000 N) and slight collateromotion. Both interphalangeal joints underwent collateromotion in the direction of the raised part of the foot (i.e., narrowing of the articular space on the side of the wedge), whereas axial rotation occurred in the direction opposite to the raised part of the foot. These results confirm the functional importance of interphalangeal joint movements outside the sagittal plane. In particular they demonstrate the involvement of the proximal interphalangeal joint in the digital balance. These data are helpful for the identification of biomechanical factors that may predispose to interphalangeal joint injury. Also the data may be of use for the rational decision making with respect to exercise management and corrective shoeing of the lame horse.     

Ethoxylated rapeseed oil derivatives as novel adjuvants for herbicides

Ethoxylates of rapeseed oil and of methylated rapeseed oil were synthesized and tested as adjuvants for 2,4-D and phenmedipham. Provided they had less than 6 units of ethylene oxide (EO), 1.0 to 10 g litre(-1) ethoxylates in water induced droplet spreading on barley leaves. In an acetone-based medium all derivatives strongly promoted the foliar uptake of 2,4-D, with no clear influence of the ethoxylation degree. In the same medium there was a negative influence of ethoxylate chain length on the foliar uptake of phenmedipham. In a water-based medium, phenmedipham applied with rapeseed oil emulsified with ethoxylated (20 EO) rapeseed oil displayed uptake rates close to a commercial preparation. The same was true for phenmedipham applied with ethoxylated (2 EO) methylated rapeseed oil. In bioassays, phenmedipham prepared with methylated rapeseed oil emulsified with ethoxylated (20 EO) rapeseed oil was as efficacious on barley as a commercial formulation. The same was true for phenmedipham prepared with ethoxylated (2 EO) methylated rapeseed oil. However, neither rapeseed oil nor methylated rapeseed oil emulsified with ethoxylated (2 EO) methylated rapeseed oil conferred good efficacy to phenmedipham. Hence, ethoxylated rapeseed oil derivatives are promising adjuvants or formulants for herbicides.     

Identification of pathogenic Leptospira strains in tissues of a premature foal by use of polymerase chain reaction analysis.

Studies were carried out to determine the cause of death in a prematurely born Thoroughbred foal that died 24 hours after birth. Necropsy revealed gross lesions suggestive of septicemia. A commercial Leptospira polymerase chain reaction (PCR) assay designed to specifically amplify the hemolysis-associated protein 1 (hap1) gene present only in pathogenic Leptospira strains detected the presence of Leptospira DNA in various tissues of the foal. Histologic examination of lung, liver, kidney, and myocardium revealed numerous spirochetes in Warthin-Starry-stained tissue sections. Results of PCR analysis and histologic examination suggested a leptospiral infection in the newborn foal. At the moment of death, the infection coexisted with a streptococcal-associated aspiration bronchopneumonia and postpartum septicemia. These findings indicate that the PCR assay based on the amplification of the hap1 gene represents a useful tool for specific detection of pathogenic leptospira in field samples taken from horses.     

The Level II aggregated forest soil condition database links soil physicochemical and hydraulic properties with long-term observations of forest condition in Europe

Key message

Aggregated, consolidated, and derived soil physicochemical data of 286 ICP Forests Level II plots were completed with soil hydraulic properties for integrated use with forest monitoring data. Database access should be requested at http://icp-forests.net . Metadata associated available at https://metadata-afs.nancy.inra.fr/geonetwork/apps/georchestra/?uuid=153e599e-6624-4e2b-b862-8124386ea9cd&hl=eng

Context

The ICP Forests database is one of the most comprehensive forest ecosystem datasets in Europe and contains the accumulated results of more than two decades of harmonised forest monitoring all over Europe.

Aims

The aim of this paper is to share knowledge on the ICP Forests Level II soil data for broader use among forest scientists.

Methods

After standard analysis, quality checks, aggregation, and calculation of derived variables (e.g. nutrient stocks, base saturation, C:N ratio, and water retention parameters), data have been gathered into a static database (AFSCDB.LII.2.2), which will be updated to new versions as soon as new measurements become available.

Results

The database provides a basis for the combined evaluation of up to 130 unique soil variables of 286 plots with dynamic data on tree growth, ground vegetation, foliar chemistry, crown condition, tree phenology, leaf area index, ozone injury, litterfall, soil solution chemistry, deposition, ambient air quality, and meteorological data assessed on the same plots.

Conclusion

The unprecedented comprehensiveness and level of detail in this newly aggregated database may overcome existing restrictions so far impeding the realisation of large-scale forest ecosystem studies in Europe.

     

An investigation of the effects of ketoprofen following rumen fistulation surgery in lactating dairy cows

Post-operative pain management following rumen surgery is not common practice. We examined the effect of providing the pain medication ketoprofen to dairy cattle following the first stage of a rumen cannulation surgery, which involves an incision in the body wall and exteriorizing and clamping the rumen. The results of this study provide clear evidence that the first stage of the surgery was painful and ketoprofen at the time of and 24 h following surgery, alleviated some, but not all, of the post-surgical pain. Pain mitigation should be included when performing flank surgery in cattle.