Aerial surveys of shore-based recreational fishing in Carnarvon and Shark Bay: June to August 2012

Aerial surveys are a useful tool for obtaining data on the spatial distribution of recreational fishing and estimating fishing effort. Following the successful application of this method in the Perth Metropolitan area, aerial surveys were conducted around Carnarvon and Shark Bay from June to August 2012. Recreational shore-based fishers were identified by fishing method (i.e., line fishing, ballooning, netting and spearfishing) and their location geo-referenced. Additional information on non-fishers, camps, boat trailers, vehicles and boats anchored or on the beach was also recorded. A combination of systematic random and stratified random sampling was employed, providing good estimates of fishing effort when conducting 6 and 9 surveys per month in Shark Bay and Carnarvon, respectively

Everyday Flux of Smallholder Beef Farming: System Overview of the Beef Farming Situation Under a Government Grant

Abstract. Smallholders dominate the beef farming in Indonesia. As a complex system, developing the smallholders need to be approached using a system thinking study. This study aimed to explore everyday activities of the smallholder beef farming which lead to an identification of any unfavorable conditions of the current situation. This is an initial step of a systems thinking approach. Descriptive study involving stakeholders of smallholder farmers group have been undertaken in KabupatenBanyumas and Banjarnegara. Descriptive analysis was performed, and a qualitative model was developed to mimic the current beef farming in both locations. Result showed that there is a growing tendency of shifting from breeding to fattening, buying and selling conditions were disadvantageous for smallholders, and the availability of grant encourage side-tracking behavior which confirmed in the model.  Key words: smallholders, beef farming, side-tracking, qualitative model, systems thinking Abstrak. Peternakan sapi di Indonesia didominasi oleh peternak kecil dalam sebuahsistem yang kompleks. Dibutuhkan pendekatan sistem untuk mempelajari sistemtersebut. Penelitianini bertujuan mengkaji aktivitas sehari-hari yang terjadi dalam sebuah sistem usaha peternakan sapi potong skala kecil untuk mengidentifikasi aktivitas yang berpotensi menjadi sumber permasalahan. Identifikasi permasalahan merupakan awal penting dari sebuah analisis sistem. Studi ini menggunakan pendekatan deskriptif dengan melibatkan pemangku kepentingan yang terkait dengan sistem usaha peternakan sapi potong di Kabupaten Banyumas dan Banjarnegara. Data dianalisis menggunakan pendekatan deskriptif dan pemodelan kualitatif. Penelitian menunjukkan adanya kecenderungan peternak untuk bergeser dari  pembibitan kearah penggemukan, praktik jual beli yang tidak berpihak pada peternak, dan kecenderungan bertambahnya side-tracker dengan meningkatnya hibah. Kata kunci: peternak kecil, peternakan sapi potong, side-tracking, pemodelan kualitatif, systems thinkin

COMPARING FUNCTIONAL DATA ANALYSIS AND HYSTERESIS LOOPS WHEN TESTING TREATMENTS FOR REDUCING HEAT STRESS IN DAIRY COWS

Various techniques are commonly used to reduce heat stress, including sprayers and misters, shading, and changes in feed. Oftentimes studies are performed where researchers do not control the times when animals use shading or other means available to reduce heat stress, making it hard to test differences between treatments. Two methods are used on data from a study where Holstein cows were given free access to weight activated “cow showers.” Functional data analysis can be used to model body temperature as a function of time and environmental variables such as the Heat Load Index. Differences between treatment groups can be tested using a Functional Bayesian MCMC model. Alternatively hysteresis loops, such as the ellipse, formed by a plot of air temperature or the Heat Load Index against body temperature over the course of a day can be estimated and their parameters used to test differences between cows with access to showers and cows without. Results from an R package hysteresis, which can estimate these loops and their parameters are illustrated. Functional data analysis allows for looser assumptions regarding the body temperature curve and the ability to look for differences between groups at specific time points, while hysteresis loops give the ability to look at heat stress over the course of a day holistically in terms of parameters such as amplitude, lag, internal heat load and central values

COMPARISON OF SAS PROC NLIN AND NLMIXED FOR PARAMETER ESTIMATION IN PET MODEL

Cattle body temperatures were measured under semi-controlled hot cyclic chamber temperatures. The four-parameter nonlinear PET model, is used to estimate body temperature in cattle challenged by heat stress. For each steer, the parameters can be estimated by the Nlin procedure and the sensitivity of each animal can be studied. It is also desirable to generalize the results by using the Nlmixed procedure to combine both the fixed and random effects. When comparing the results from the two procedures, we found heterogeneity among animals and/or days caused convergence problems for proc Nlmixed. Simulation studies were used to study how deviations from homogeneity effected the accuracy of parameter estimates, coverage of confidence intervals, and measures of nonlinear behavior when using the PET model to describe the dynamics of heat stress in cattle

Spatial distribution of shore-based fishers in the greater Perth Metropolitan area over summer 2010/2011

Aerial surveys are a useful technique for estimating numbers of recreational fishers. Following the success of a pilot study to examine the spatial patterns of recreational shore-based fishing activity in the Perth Metropolitan area from April – June 2010, another survey was conducted from December 2010 – February 2011 between Lancelin – Bunbury. More than 7,000 shorebased fishers were counted during 36 aerial flights, with significantly more recorded on morning and afternoon flights, when compared to those conducted at midday. Flights on weekends/public holidays also recorded more fishers than weekdays. The spatial distribution of fishers was variable along the coast, with sandy beaches at the northern and southern sections of the study area having high counts of fishers, along with groynes in the central section. Comparisons with the previous (autumn) study revealed that the northern beaches generally had higher numbers of shore-based fishers in summer, while those in the south had more during autumn. Data from this study assists with understanding the patterns of shore-based recreational fishing occurring along the greater Perth Metropolitan coast. Such information can be used to assist in the design of future on-ground surveys, compliance and education activities

Vapor Distribution above an Evaporating Sessile Drop

An experimental technique was developed that uses infrared tomography to measure the three-dimensional vapor distribution above an evaporating sessile drop. The technique was applied to measure the vapor distributions above evaporating drops of hexane and 3-methylpentane (3MP) at room temperature and pressure. The molecular masses of these two species are heavier than air and the vapor from the evaporating drop forms a flat, disk-shaped cloud. A Fourier transform infrared spectrometer (FTIR) was used to measure the spectral absorbance along a set of paths passing through the vapor cloud. From a set of path-averaged absorbance measurements, a two-dimensional spatial concentration distribution was determined using a computed tomography routine. A three-dimensional concentration distribution was obtained from multiple two-dimensional distributions obtained at different elevations above the drop. The vapor distributions for both hexane and 3MP differ significantly from the values predicted by the solutions for diffusion-limited evaporation and indicate the effect of buoyancy-induced convection of the vapor. These measurements are the first quantitative measurements of the vapor distribution above a sessile drop and are important for advancing the understanding of the vapor phase transport mechanisms, and thus sessile drop evaporation

Quantifying recreational fishing catch and effort: a pilot study of shore-based fishers in the Perth Metropolitan area

Recreational fishing is a popular activity throughout Western Australia, including adjacent to the populous Perth Metropolitan area. Understanding the level of catch and effort associated with this activity is essential for the sustainable management of fish stocks. Whilst the focus of recent surveys in the Perth Metropolitan area has been on boat-based fishers targeting demersal species, shore-based fishing has not been measured for many years. Recent changes to management controls for these demersal species, including the implementation of a fishing boat licence, may increase existing pressures on nearshore stocks by displacing fishing effort onto these resources. Therefore, a need exists for the collection of information on the behaviour and catch of recreational shore-based fishers to support management measures

Effects of selenium and vitamin E on performance, physiological response, and selenium balance in heat-stressed sheep

Forty-two 7-mo-old Australian Merino wethers were used in a 50-d trial to investigate the effects of Se and vitamin E on the performance and physiological responses of heat-stressed sheep. Sheep were exposed to thermoneutral conditions (maximum = 24°C and minimum = 20°C) for 28 d followed by heat (maximum = 38°C and minimum = 28°C) for 22 d. Hot conditions were imposed between 0700 and 1800 h. Sheep were randomly allocated to diets containing 0.8 mg/kg Se (Sel-Plex), 150 mg/kg vitamin E, or 0.8 mg/kg Se and 150 mg/kg vitamin E for either the duration of the study (50 d) or from d 1 of the hot period until the end of the study. A control group that received no supplemental Se and vitamin E for the duration of the study was included. Feed intake was measured daily and sheep were weighed weekly. Blood samples were collected from all sheep before feeding on d 1, 21, and 49 for measurement of biochemical and enzymatic variables. The concentration of Se was determined in offered and refused feed, feces, urine, water, plasma, liver, and kidneys. Exposure to heat reduced (P < 0.05) DMI by 11.9%, ADG by 198 g, serum concentration of urea nitrogen and Se by 17.8%, and plasma total antioxidant status by 26.4%. During hot conditions, sheep receiving Se and vitamin E supplements for 50 d had reduced (P < 0.05) BW loss and elevated G:F compared to control sheep. Serum Se concentration and the plasma total antioxidant status were greatest in sheep receiving Se and vitamin E supplements for 50 d (P < 0.05). These results indicate that dietary supplementation with Se and vitamin E reduces the adverse effects of a high heat load. Additional studies are warranted to elucidate the mechanisms responsible for these effects