Water quality, bacterial flora and production in shrimp farms in Sri Lanka

This study investigated the possibilities of improvement in the brackish water shrimp culture industry in Sri Lanka. Feeding rates could be further reduced without negative effect on shrimp growth while improving effluent water quality. Improvements of feed quality and pond management practices were also suggested.

Epidemiology and management of Penaeus monodon farms in Andhra Pradesh, India

Disease outbreaks on shrimp farms studied in Andhra Pradesh were caused mainly by white spot syndrome virus (WSSV) significantly reducing yield. Shrimp seed was the major source of WSSV but several risk factors were also involved. Implementation of better management practices (BMPs) at farm and farm cluster level through formation of Self-Help Groups could significantly improve crop outcomes in farms.

Identification of a putative egg-laying hormone in neural and ovarian tissues of the black tiger shrimp, Penaeus monodon, using immunocytochemistry

The existence of an egg-laying hormone (ELH) was identified for the first time in the black tiger shrimp, Penaeus monodon, by means of immunoenzyme and immunofluorescence techniques. This was achieved using a polyclonal antibody produced against expressed recombinant ELH of the female Australian blacklip abalone, Haliotis rubra. The shrimp ELH reactive material was found to be localised within female neurosecretory tissues and the secretory tissue of the antennal gland, but was not identified in the X-organ sinus gland within the eyestalk. It was also present in the ovary, where the amount of ELH present was observed to be greatest in the period prior to spawning. These findings implied that the induction of P. monodon spawning might be involved with humoral regulation relating to ELH expression.

Domestic drinking water in rural areas : are water tanks on farms a health hazard?

The aim of the research was to gain a better understanding of the relationship between drinking water quality, householders' knowledge and maintenance practices of private water supplies and drinking water-related public health risk on farms. Samples of drinking water were taken from 100 farming households. The Colilert-18 method was used for the detection of total coliforms and Escherichia coli (E. coli) as indicators of water quality. Each household completed a questionnaire about their knowledge and practices relating to a safe water supply. Coliforms were present in 52 water samples and E. coli was present in 38. Seven households reported minor illnesses in the previous three months and two households reported gastroenteritis. Some tank maintenance occurred in 86 households, but tank maintenance activities varied considerably. Four of the households had published guidelines on water quality. None of the participating households had their drinking water tested regularly. There was no obvious relationship between drinking water quality, householder knowledge, maintenance practices and drinking water-related health risk on farms.

Efficiency measurement of Australian dairy farms: national and regional performance

In this paper we use Data Envelopment Analysis (DEA) to estimate technical efficiency for a sample of 1742 Australian dairy farms. Bearing in mind data limitations we find that average technical efficiency is 59 per cent, but there are significant regional differences. These results reflect differences in State level milk marketing arrangements in place before dairy deregulation in July 2000 providing an ex post explanation for the changing composition of dairy farms in Australia. We also examine two important technical aspects of DEA implementation. First, how changes in model input specification alter the relative performance of farms. Second, we employ a simple bootstrap procedure to show how changes in sample size affects estimates of technical efficiency. These results have simple but important implications for the use of DEA as an industry-benchmarking tool.

A global perspective of aquaculture in the new millennium

In modern times, not many primary industries have consistently recorded high yearly growth over a period of two decades. Aquaculture has sustained a global growth, continues to grow, and is expected to increasingly fill the shortfall in aquatic food products resulting from static or declining capture fisheries and population increase well into the year 2025. Its further growth and development will have to occur under a different socio-economic milieu in the new millennium. The basic paradigm changes will be from an increased production at almost any cost, to a sustainable increase in production with minimal environmental perturbations. Despite such paradigm changes, aquaculture will increasingly contribute to food security, poverty alleviation and social equity. The contribution of aquaculture to world food supply of aquatic products has been increasing over the past 10 years, in comparison to capture fisheries, growing from 15 to 28 percent of total production between 1988 and 1997. As the bulk of aquaculture is rural and subsistence, it plays a major role as a provider of direct and indirect employment to the rural poor and, thereby, to poverty alleviation. In many developing countries, aquaculture provides opportunities for diversification on agriculture farms and productive use to otherwise idle land during certain seasons. The main cause for the upsurge in the sector has been the transformation of aquaculture from an “art” form to a “science”. This brought many advantages, ranging from less dependence on wild stock to the development of techniques that optimized yields, such as polyculture, or enabled the achievement of high yields with low inputs. Two major developments also enabled the sector to maintain growth momentum, appropriate institutional frameworks and concerted research and development. Regions or continents have many commonalities. These include the predominance of finfish among the cultivated species, and the predominance of species that feed lower in the food chain, although shrimp, which does not naturally feed high in the trophic level but is mostly reared on artificial feed, has become a significant culture commodity. Notable differences, however, include the fact that all regions, except Africa and the countries of the former USSR, have recorded a significant increase in per capita production between 1984 and 1997. While Asia continues to dominate world aquaculture in overall tonnage, as well as in every major commodity, South America has registered a very high (72.8 percent) average annual growth between 1984 and 1997. The global and regional trends over the last 20 years in the sector from a number of perspectives, such as production trends, contribution of aquaculture to aquatic food consumption etc., are evaluated. Based on these different trends and in the light of changing socio-economic conditions globally, and in particular, in developing nations, the potential changes in the sector in the new millennium are highlighted. Finally, projections are made for the next 20 years, where opportunities, constraints and strategies for achieving the targets are presented and discussed.

Scale efficiency in Australian dairy farms

Data Envelope Analysis, (DEA), a linear programming technique, provides a more consistent measure of efficiency than the commonly cited partial measures of farm efficiency. It yields a relative measure of efficiency and identifies inputs or outputs that are under utilized.

In this paper, DEA is used to assess the technical efficiency of a sample of dairy farms across all dairy regions in Australia. Regions vary in size and scale of operation and are examined to see the relationship between farm size and technical efficiency, and to see if there is justification in the move towards bigger dairy production units than currently exist, given their factor mix.

Environmental efficiency : meaning and measurement and application to Australian dairy farms

Technical efficiency has been widely studied in the literature, but in its pursuit, many of the inputs used can impact on the environment. Environmental effects can be modelled as undesirable output or, as has been the case in more recent studies, as conventional inputs. This paper examines the concept of environmental efficiency and how it can be used to evaluate the performance of Australian dairy farming, using nitrogen surplus, arising from excessive applications of fertilizer, as a detrimental input. Farming promotes the image of clean and green production and if this image is to be maintained, there is a need to ensure activities are environmentally friendly.

Using benchmarking to improve the financial and social sustainability of commercial goat meat, cashmere and mohair farms in Australia

Production and financial benchmarking was undertaken with commercially motivated mohair, cashmere and goat meat farmers in Australia. There were large differences in animal and fleece production and financial returns between the best and worst performing farms. Farmers and industry groups reported that the process and results were helpful and resulted in them changing management practices. Benchmarking demonstrated that there is substantial scope to increase productivity and profitability through improved genetic selection and improved management of pastures, breeding flocks and in kid survival and growth.

Molecular systematics of the Australian freshwater shrimp, Paratya australiensis

Molecular genetic date was used to test the taxonomic hypothesis of a single species of the freshwater shrimp, Paratya australiensis. While the results identified significant cryptic diversity, clear species boundaries could not be defined. The results of this study defy a simple taxonomic conclusion but are suggestive of incipient speciation.