Use of geographical information systems as a tool for predicting fish yield in tropical reservoirs: case study on Sri Lankan reservoirs

Use of geographical information systems (GIS) in inland fisheries has hitherto been essentially restricted to site evaluation for aquaculture development and assessment of limnological changes in time and space in individual water bodies. The present GIS study was conducted on the land-use pattern of the catchments of nine reservoirs in Sri Lanka, for which detailed fishery data, viz. yield, fishing intensity, landing size of major constituent species, together with selected limnological data such as conductivity and chlorophyll- a , were available. Potential statistical relationships (linear, curvilinear, exponential and second-order polynomial) of fish yield ( FY , in kg ha⁻¹ yr⁻¹) to different land-use patterns, such as forest cover ( FC , in km²) and shrub-land ( SL , in km²), either singly, or in combination, and/or the ratio of each land type to reservoir area ( RA in km²) and reservoir capacity ( RC in km³), were explored. Highly significant relationships were evident between FY to the ratio of SL and/or FC + SL to RA and/or RC . Similarly, the above land-use types to RA and RC ratios were significantly related to limnological features of the reservoirs. The relationships of FY to various parameters obtained in this study were much better correlated than those relationships of FY to limnological and biological parameters used in yield prediction in tropical and temperate lacustrine waters previously.     

Demand and effect of potassium,magnesium, and calcium chlorides on hemolymph parameters,immune-related gene expression,and growth of Litopenaeus vannamei,Boone (1931) under biofloc technology

The ionic composition of culture water may be a more important limiting factor than the salinity itself and may lead to osmotic stress which may influence growth and survival of shrimp culture. The uptake rate and the effect of magnesium chloride (MgCl₂), calcium chloride (CaCl₂), and potassium chloride (KCl) salts in juveniles of whiteleg shrimp (Litopenaeus vannamei) cultured with biofloc technology (BFT) was evaluated for 62 days in seawater (30 practical salinity unity). Five treatments were analyzed in triplicate: T1; control (water exchange rate of 5% daily), T2; adding CaCl₂?+?MgCl₂?+?KCl, T3; adding MgCl₂?+?KCl, T4; adding CaCl₂?+?KCl, and T5; adding CaCl₂?+?MgCl₂. Mineral salts were added to water and the response of experimental parameters: physicochemical variables of water quality, osmotic pressure, total hemocyte count, glutathione peroxidase gene expression, superoxide dismutase, and zootechnical variables of the shrimp was assessed. The uptake of single chloride salts (CaCl₂, MgCl₂, and KCl) by shrimp varied as a function of the concentrations and the ratio of these three ions. Magnesium deficiencies in the culture medium increased CaCl₂ and KCl uptake without showing gene expression of SOD and GPx. The best survival rate was obtained by adding the three ions (T2) and the control (T1, water exchange of 5%). We concluded that L. vannamei can be maintained by the addition of essential chloride ions in BFT without water replacement.

     

Clinical findings related to intramammary infections in meat-producing ewes

The aim of this study was to investigate the relationship between clinical findings and bacterial isolation in milk samples of meat-producing ewes. The study was conducted in 17 commercial flocks and 550 udder halves from suckling Santa Ines ewes. Initially, the clinical examination of the mammary glands and teats was performed by visual inspection and palpation of the teats and udder halves; then a scoring system was devised for all the findings. After that, the strip cup test and the California mastitis test (CMT) were performed. Then, milk samples for somatic cell counts (SCCs) and bacteriological analyses were collected. Staphylococci bacteria were the main etiological agent isolated in the present study. Upon investigation of the correlations between bacterial isolation and the clinical findings, only the presence of teat injury, pendulous udder, and alterations in the palpation of the teat were associated with bacterial isolation. A significant correlation between bacteriologically positive milk samples and CMT and SCC was also found. Thus, some clinical findings appeared as a risk factor for bacteriologically positive milk samples and can be used as a tool in mastitis control programs. However, a complete and extensive diagnosis, an appropriate therapy, and an efficient mastitis control program will require the combination of clinical examination, microbiological tests, and SCC.     

Effect of the replacement of Tifton 85 with maniçoba hay on the performance of Morada Nova hair sheep

The use of native and adapted forages is an alternative for sustainable production systems in northeast Brazil. The goal of this study was to evaluate the substitution of Tifton 85 by maniçoba hay on the performance and carcass traits of Morada Nova hair sheep. The 16 lambs that were used in this study initially weighed 19.36?±?1.48 kg, were housed in individual pens, and were slaughtered at 58 days of confinement. The dry matter intake (839.84 g/day and 3.81 % WB) was higher (P?<?0.05) in sheep fed maniçoba hay. The feed conversion was 7.39 for sheep fed maniçoba hay. The empty body weight (21.61 kg) and cold carcass weight (11.40 kg) did not differ (P?>?0.05) between sheep fed different hay types. The replacement of Tifton 85 by maniçoba hay did not influence the loin eye area (cm²) or carcass compactness index (kg/cm). The replacement of Tifton 85 by maniçoba hay in Morada Nova sheep diet did not affect the weight gain or carcass characteristics. The maniçoba hay can be considered a forage resource for feeding sheep in Brazilian semiarid tropics.     

Porcine salivary analysis by 2-dimensional gel electrophoresis in 3 models of acute stress: A pilot study

The purpose of this research was to study changes in the salivary proteome of healthy pigs in stressful situations to identify any potential new salivary biomarker of stress. Three groups of animals were subjected to 3 stress models: snaring restraint followed by simulated sampling of vena cava blood; brief transport by road; and restriction of movement in a digestibility cage. Saliva was obtained from each animal before and 15 and 30 min after the induction of stress. The samples from the animals that showed the greatest increase in salivary cortisol concentration were pooled and run on 2-dimensional gels. Coomassie Brilliant Blue R-250 was used for spot detection and mass spectrometry for spot identification. Statistical analyses showed that 2 proteins had significant differences in expression before and after the induction of stress. These proteins were identified as odorant-binding protein and fragments of albumin. Further studies will be necessary to confirm the value of using these proteins as salivary biomarkers of stress in pigs.     

Effect of rider experience and evaluator expertise on subjective grading of lameness in sound and unsound sports horses under saddle

The primary objective of this study was to investigate whether rider experience influences the assessment and grading of lameness in horses based on under-saddle gait analysis. Thirteen adult sports horses in active training were included in the study. After a baseline lameness and neurologic examination by the principal investigators, horses were videotaped while being ridden by an experienced and a less experienced rider. A 3-minute video was made for each horse and rider and 26 videos were randomly ordered and compiled on a DVD. Veterinarians with different levels of experience in evaluating lameness and veterinary students viewed the DVD and assigned a lameness score to each horse/rider combination. In a model accounting for the expertise of the evaluator, there was no difference in overall lameness scores between experienced and less experienced riders. This result was consistent for both sound and unsound horses. The overall lameness scores reported by specialists and students, however, differed significantly. The lameness score reported by the study participants while the horse was ridden was significantly associated with the subjective baseline lameness assessment reported by the principal investigators for the same limb when the horse was not under saddle. Additional work is necessary to determine whether riders with even lower skill levels would further alter the balance and motion pattern of the horse and have more influence on subjective grading of lameness.     

Evolution of forest cover in Portugal: A review of the 12th–20th centuries

Portugal's forests in the 12th century were dominated by the Fagaceae represented by Quercus and Castanea, and several pine species.From the 12th century onwards, forests underwent changes in their management starting with protection and ultimately leading to intense exploitation. The massive naval construction during the maritime expansion(mainly in the 15th–16th centuries) involved felling of approximately 5 million trees mainly Quercus suber, Pinus pinea and other Quercus species. Cumulative fuel-wood consumption of 959 Mm3 during 1300–1854 was attributed to demographic expansion while the deforestation rate during 1636–1854 accounted for a minimum of 72.6% and a maximum of 96% of total forest cover. The volume of timber used in railway sleepers from 1856 onwards might have reached 0.5 Mm3. The last quarter of the 20th century increased the forest cover of Portugal through the World Bank program of Eucalyptus globulus reforestation.     

Stem mapping and estimating standing volume from stereoscopic hemispherical images

Sustainable forest management requires knowledge of forest structure and dynamics as well as an estimation of growing stock. The forest inventory provides the data for estimating stand variables. The measurement device MU2005-01738, patented by the Center for Forest Research (INIA-CIFOR), provides stereoscopic hemispherical images which can allow the 3D restoration of the stand around the sampling point. The aim of this study is to develop a methodology for forest stand mapping as well as tree diameter and height measurement along with volume estimation from the stereoscopic hemispherical images provided by the MU2005-01738. Using the MU2005-01738, Eucalyptus globulus Labill. plantations were sampled. Distance, diameter, height and volume were derived from the stereoscopic hemispherical images of 30 trees located at distances ranging from 0 to 15 m from the device. These variables were then compared with field measurements and the estimation errors analyzed. The (root-mean-squared error) RMSE was 0.23 m (8.95 %) for tree position and 1.51 cm (10.43 %) for diameter at breast height measurement at distances of less than 8 m. In the case of stem height and individual tree volume estimation, the RMSE was 2.59 m (23.05 %) and 0.025 m³ (17.94 %), respectively. The analysis of measurement errors indicated that the measurement precision decreases beyond 8 m from the device as well as for directions close to the baseline (the line between the optical centers of the two images), whereas the precision was highest for directions near to the line which is perpendicular to the base line. Future research should focus on improving measurement accuracy and possible applications in the field of forestry of the techniques presented in this study.     

Influence of artificial insemination on the reproductive performance of Farfantepenaeus paulensis in conventional and unisex maturation systems

The application of artificial insemination techniques as a way to overcome the lack of mating of the closed thelycum Farfantepenaeus paulensis under large scale conditions is reported. The performance of artificially inseminated females (49.4±11.6 g) maintained in conventional versus unisex maturation systems was compared. Groups of unilaterally eyestalk-ablated females were artificially inseminated with one compound spermatophore soon after molting. The percentage of fertilized spawns increased from 26% before the use of artificial insemination to 57% afterwards. The reproductive performance of inseminated females held in conventional or unisex maturation systems showed no significant differences. Artificial insemination was considered a practical approach to overcome the lack of mating of F. paulensis under large-scale conditions with acceptable reproductive performance. The results also indicate the possibility of holding females separately from males, which could mean significant improvements in maturation systems through the increase in the stocking density of spawning females.