A taper function for Pseudotsuga menziesii plantations in Spain

Five stem taper models belonging to three different taper function categories were fitted to data corresponding to 282 Pseudotsuga menziesii trees. The trees were selected in the area surrounding 61 research plots installed in Galicia, Asturias and the Basque Country, northern Spain. The models were simultaneously fitted to observed values of diameter outside bark and inside bark. A third-order continuous-time autoregressive error structure was used to account for autocorrelation. Selection of the best model was based on both numerical (goodness-of-fit statistics) and graphical analysis (plots of residuals against position along the stem and against tree size). The three-segmented taper model finally selected has the advantage of being compatible with both a merchantable and a total stem volume equation.     

Aetiology and histopathology of bovine mastitis of espontaneous occurrence

Infectious bovine mastitis is responsible for serious economic losses in dairy cattle breeding. Information about the damages caused by micro-organisms is of great interest and importance. The purpose of the present study was to report on the microbiological and histopathological aspects of the mammary parenchymas of slaughtered dairy cows. A total of 184 mammary glands were examined and samples of mammary parenchyma were collected for microbiological and histopathological examinations. Micro-organisms were isolated from 69.6% samples; 23 (12.5%) of the 184 samples did not show histological changes; inflammatory response was observed in 56 (30.4%) samples; inflammatory response and repair were present in 82 (44.6%) samples; repair process was verified in 23 (12.5%) of the mammary glands. Coagulase-negative Staphylococci were observed in 53.8% of the samples followed by coagulase-positive Staphylococci (7.6%), Prototheca sp. (2.2%) and Streptococcus dysgalactiae (1.6%). Coagulase-negative Staphylococci and coagulase-positive Staphylococci were associated mainly to chronic inflammatory response and chronic inflammatory response and repair. Samples from which no micro-organisms were isolated (n = 56) had no histological changes in 82.6% of the cases. These results were higher (P < 0.05) when compared to the samples with micro-organisms and without histological changes (17.4%).     

Comparison of Holding Power of Three Different Pin Designs for External Skeletal Fixation in Avian Bone: A Study in Common Buzzard (Buteo buteo)

Objective— (1) To evaluate resistance to axial extraction of 3 pin designs in avian humerus and tibiotarsus; (2) to assess the effect of pin location within the bone on holding power; and (3) to assess the influence of thread pitch on holding power. Study Design— Resistance of pins to axial extraction was measured immediately after insertion. Animals— Adult common buzzards (Buteo buteo; n=9). Methods— Different pin designs (1 smooth; 2 threaded pins, differing in pitch) were inserted into the proximal and distal metaphysis and the proximal, middle, and distal diaphysis of the humerus and tibiotarsus. Maximum force required for axial extraction of pins was recorded. Results— Smooth pins had the lowest extraction force (P<.05). Pins inserted into the diaphysis (proximal, middle and distal) of the humerus and the distal metaphysis of the tibiotarsus had a greater pullout strength than pins in other locations. Pins with a smaller pitch inserted into the proximal diaphysis and distal metaphysis of the humerus, and the proximal metaphysis of the tibiotarsus had significantly greater holding power than pins with a larger pitch (P<.05). Conclusions— Pins inserted into the diaphysis of humerus and the distal metaphysis of the tibiotarsus are better at resisting extraction. Pins with a smaller pitch possess greater holding power than pins with a larger pitch in avian humerus and tibiotarsus. Clinical Relevance— Consideration should be given to pin location and thread pitch, when choosing external skeletal fixation to repair an avian humeral or tibiotarsal fracture.     

Evaluation of on-farm irrigation applications using the simulation model EPIC

An understanding of water needs in agriculture is a critical input in resolving the water resource issues that confront many southeastern and other US states. The objective of this study was to evaluate on-farm irrigation applications for three major crops grown in Georgia, USA using the Environmental Policy Integrated Climate (EPIC) model. For cotton, 16, 58, and 75 farmers fields in 2000, 2001, and 2002, respectively, were selected from among the Agricultural Water Pumping (AWP) program sites across the state of Georgia. For maize, 9, 20, and 28 fields were selected in 2000, 2001, and 2002, respectively, and for peanut, 18, 51, and 54 fields were selected in 2000, 2001, and 2002, respectively. The majority of these fields were located in the southwest region of Georgia, where traditional row-crop agriculture is most dominant. We compared the simulated irrigation requirements with the amount of water that the farmers actually applied during the 2000, 2001, and 2002 growing seasons. For cotton and peanut, the means of farmer-applied irrigation amounts and simulated irrigation requirements agreed very well, with similar values for root mean squared deviation (RMSD) of the two crops. For maize, good agreement between simulated and farmer-applied irrigation amounts were found only in 2001. Farmers applied more water to their maize crop when compared to simulated irrigation requirements, especially when rainfall was very low and potential evapotranspiration was high during the 2000 and 2002 growing seasons. The component of the mean squared deviation (MSD = RMSD²) related to the pattern of variability in seasonal irrigation applications contributed most to MSD. Accurate estimates of the mean and the magnitude of variability in seasonal irrigation applications could be very useful for the estimation of overall water use by agriculture in Georgia and other southeastern states. This study showed that the EPIC model would be an adequate tool for this purpose; potential users could include policy makers, planners and regulators, including the Georgia Department of Natural Resources (DNR).     

Effects of Long-term Cyanide Ingestion by Pigs

Animal performance and health status are adversely affected by long-term cyanide ingestion; however, the effects of cyanide ingestion by pigs have not been fully determined. The aim of the present study was to determine the effects of prolonged exposure to different doses of potassium cyanide (KCN) in growing-finishing swine. Twenty-four pigs, 45 days of age, were divided into four equal groups and treated with different doses of KCN: 0, 2.0, 4.0 or 6.0 mg per kg body weight per day for 70 consecutive days. The results showed a significant alteration in thiocyanate, creatinine and urea levels and in alanine aminotransferase activity of swine dosed with 4.0 and 6.0 mg/kg/KCN. Thyroid weight was significantly increased in those pigs from 4.0 mg/kg KCN group, but no change in cholesterol, triiodothyronine or thyroline levels were observed. Body and carcase weights, body weight gain, and bacon thickness were not affected by KCN treatment. The histopathological study revealed increased numbers of vacuoles in the colloid of thyroid follicles, degeneration of cerebellar white matter and Purkinje cells, degeneration of renal tubular epithelial cells, caryolysis and pyknosis in hepatocytes, and disturbance of the normal lobular architecture of the liver in all treated pigs. Thus, long-term administration of KCN to swine affects several tissues and could adversely affect animal production.     

Effect of colostrum redox balance on the oxidative status of calves during the first 3 months of life and the relationship with passive immune acquisition

New-born calves depend upon colostrum intake for the acquisition of immunoglobulins (Ig) and other beneficial substances. However, colostrum is also a source of reactive oxygen species (ROS). Intrinsic production of ROS also increases after birth, so the combination of colostral and intrinsic ROS could overwhelm the antioxidant capacity of the calf leading to oxidative stress (OS), a condition that has been shown to play a key role in the initiation and development of several pathological conditions.The aim of this observational study was to assess the effects of the redox balance of colostrum on the oxidative status of calves and on passive immune transfer. Serum samples were taken from 20 calves on their day of birth, every week during their first month of life and at 2 and 3 months of age, and the concentrations of ROS and serum antioxidant capacity (SAC) assayed. The oxidative/anti-oxidative profile and IgG content of the colostrum were also assessed.The redox balance of the colostrum had a significant effect on both calf oxidative status and on passive immune transfer (as measured by calf serum IgG concentration), which indicates that the oxidative/antioxidative profile of colostrum should be measured when colostrum quality is assessed. The highest risk of OS during the study period was found to be when the calves were fed artificial milk replacer; this suggests that calves should be supplemented with antioxidants during this period in order to minimize any harmful consequences of high ROS generation.