Using full-scale duckweed ponds as the finish stage for swine waste treatment with a focus on organic matter degradation

Artigo Publicado em: IWA - Water Science & TechnologyThe rapid increase in the number of swine has caused pronounced environmental impacts worldwide, especially on water resources. As an aggregate, smallholdings have an important role in South American pork production, contributing to the net diffusion of pollution. Thus, duckweed ponds have been successfully used for swine waste polishing, mainly for nutrient removal. Few studies have been carried out to assess organic matter degradation in duckweed ponds. Hence, the present study evaluated the efficiency of two full-scale duckweed ponds for organic matter reduction of swine waste on small pig farms. Duckweed ponds, in series, received the effluent after an anaerobic biodigester and storage pond, with a flow rate of 1 m3 day 1. After 1 year of monitoring, an improvement in effluent quality was observed, with a reduction in biochemical oxygen demand (BOD) and total chemical oxygen demand (tCOD), respectively, of 94.8 and 96.7%, operating at a loading rate of approximately 27 kgBOD ha 1 day 1 and 131 kgCOD ha 1 day 1. Algae inhibition due to duckweed coverage was strongly observed in the pond effluent, where chlorophyll a and turbidity remained below 25 μg L 1 and 10 NTU. Using the study conditions described herein, duckweed ponds were shown to be a suitable technology for swine waste treatment, contributing to the environmental sustainability of rural areas

Optimising production systems for organic pig production (OF0169)

This is the final report of Defra project OF0169. There is a more comprehensive Executive Summary at the start of the attached main report. The overall objective of this project was to generate the scientific and financial information necessary to facilitate increased production of pigmeat on existing organic farms, and the conversion of conventional farms to this organic production. Information was collected through a series of experiments focusing on the effects of genotype, management and nutrition. The study was conducted on commercial organic pig farms, supported by literature searches, financial appraisal, and survey data collection. Organic production standards favour traditional breeds of livestock in preference to ‘improved’ genotypes, which may be less suited to the more extensive production systems. An experiment was carried out to compare performance, health and welfare of three different genotypes managed organically. These genotypes were chosen to represent different breeding strategies - British Saddleback (S), a pure-bred, traditional genotype; PIC Camborough 12 (C12), an improved modern genotype; and Saddleback x Duroc (SD) sow, suitable for ‘criss-cross breeding’ system by smaller organic farms. The modern improved genotypes of sows produced higher litter sizes than their more traditional counterparts, although the numbers of pigs weaned were similar across the genotypes studied. The results indicated that all three breeding strategies can be successfully adopted in organic production systems, and that choice of sow breed should depend on the ability of the farm to manage prolific sows, the implications for slaughter pig performance, and market requirements. A factorially designed experiment was carried out to investigate the effects on performance and carcass quality of three different genotypes of growing pig, three feeding systems and two housing systems. Overall, there were few significant treatment effects on product quality. In a further experiment, the herbage intake of growing pigs maintained at pasture was quantified. The results showed that, when offered a cereal- based concentrate ad libitum, the herbage intake of growing pigs from a good quality grass/clover sward contributed <5% to daily organic matter consumption. In these circumstances, modification of concentrate composition would not be appropriate. To facilitate efficient feed use in organic pig production, a ‘Feed Handbook’ (publication C3) was compiled, printed and made available to UK organic farmers. The effect of paddock management on the ranging behaviour of sows was also studied in a two by three factorial design, involving three sow genotypes. Two commercially applicable paddock management strategies were established: a) ‘Rotational’ (R) where a group of up to 6 sows was relocated to clean ground every four months, and b) ‘Set stocked’ (SS) where a group of up to 6 sows was relocated to clean ground every twelve months. Results suggest that during wet periods, the R paddocks may be advantageous as the pigs are moved off damaged pasture, whereas in drier periods, the SS paddocks maintain grass cover for longer than R and therefore incur less labour for moving without significant pollution risk. Pigs in the SS paddocks do use the further portions of the field, but this may require management manipulations to achieve satisfactory grass usage and distribution of excreted nutrients. In a survey conducted between August 1999 and April 2002 on the commercial organic farms, the main welfare issues reported related to keeping stock clean and dry in periods of high rainfall, managing Porcine Dermatitis and Nephropathy Syndrome and Postweaning Multisystemic Wasting Syndrome (PDNS/PMWS) within their herd, and recruiting and retaining good quality personnel. Mange and lice were the highest-ranking current health concerns, and post-mortem reports of endo-parasitism was the highest-ranking historical health concern. Two of the five farms surveyed reported problems with scouring in young pigs probably due to Coccidia, which may pose a significant risk in organic systems. Data collected on physical performance, capital investment and operating costs were used to establish bench-mark production levels for organic pig herds, the cashflow implications of establishing an organic pig herd, profitability, and sensitivity to movements in productivity, costs and prices. This showed the potential for profitability, which was vulnerable to price fluctuations. Information was disseminated widely through farmer conferences and talks at national conferences, scientific papers, conference proceedings, technical and press reports

USING NATURE AS BOTH MENTOR AND MODEL: ANIMAL WELFARE RESEARCH AND DEVELOPMENT IN SUSTAINABLE SWINE PRODUCTION

Livestock Production/Industries,

Enteric diseases in pigs from weaning to slaughter

The general aim of this thesis was to study enteric diseases in growing pigs, with special reference to diseases caused by Brachyspira hyodysenteriae and Lawsonia intracellularis. The occurrence of enteric diseases in “growers” is a problem of increasing importance in Sweden and an understanding of the mechanisms by which the microorganisms causes enteric diseases is essential to develop good prophylactic measures. The most important microorganisms involved in enteric diseases in grower pigs were identified as Lawsonia intracellularis and Brachyspira pilosicoli, as determined by necropsy, microbiological and histopathological examinations performed on representative growing pigs from good and poor performing herds. Diagnostic methods based on polymerase chain reaction for L. intracellularis in tissue or faecal samples were established and the results related to those obtained by necropsy and serology. An internal control, a mimic, was constructed to demonstrate inhibition of the PCR reactions and to evaluate different preparation methods. The methods for the demonstration of L. intracellularis in tissue samples were sensitive and specific, and the bacteria were reliably identified in faeces from pigs with overt disease. A number of factors interacting in the clinical expression of swine dysentery were evaluated. In this work, group-housing of pigs and the addition of 50% soybean meal in feed was shown to predispose for infection. A model was developed that enabled the sequential monitoring of disease in single animals by repeated endoscopy and biopsy sampling through a caecal cannula. This reduced the number of experimental animals required and increased the accuracy of the study. The general condition of the animal was not affected. The model was used to study the development of experimentally induced swine dysentery and the sequential development of lesions was characterised by histopathology and immunohistochemistry. An increase in the acute phase proteins serum amyloid A and haptoglobin and in monocytes was seen when haemorrhagic dysentery occurred

Economic importance of ensuring the welfare for farm pigs

Lately it speaks a lot about ensuring animal welfare and about the influence of the environment on life and on animal performance. Pig farming depends heavily on the environment because pigs needs all the elements for the comfort (enough space for sleep and movement, enough food depending on nutritional requirements for the animal category, water ad libitum, and health insurance) for growth and to deposit bonus. When these needs are not respected, pigs begin to lose weight and that affect the production and the economic efficiency of the farm. The purpose of this study is to provide necessary information that have an important influence on the production and on the economic efficiency of the farm when animal requirements are not met, but also to known and combating stress factors. The material is addressed to farmers and both to those who want to set up a pig farm

Chapter 1: Basic Principles of the Thermal Environment and Livestock Energetics

Description of the thermal environment and the livestock response can be complex, and has been the subject of extensive research for over fiver decades inspired in part by a joint report sponsored by ASAE (now ASABE) and ASHRAE. This 1959 report presented the State of the Art of the thermal environmental requirements of poultry (Stewart and Hinkle, 1959), dairy cattle (Yeck, 1959), beef cattle (Nelson, 1959), swine (Bond, 1959) and sheep (Kelly, 1959). Even though the report was comprehensive, data were noted as being incomplete for understanding the biophysical interactions between the animal and its thermal environment as required for effective management and engineering design. Heat loss for poultry was primarily based on basal (fasted) conditions, for example, and the role of the skin and hair in heat dissipation from cattle was inadequate. Comprehensive studies have been conducted in the intervening 50 years to evaluate the effects of nutrition, acclimation or conditioning, dynamic changes in the environment, physiological state, and social interactions on livestock productivity responses to the thermal environment: temperature, humidity, radiation, and air velocity

Analysis of black holes in our knowledge concerning animal health in the organic food production chain

Although a large body of research on health aspects can be found via the web or in conference proceedings, only few papers reach the peer reviewed literature. This aspect makes it difficult to judge the quality of available data that relate to health aspects associated with organic livestock production. Many data deal with "on farm case type studies" which often do not lead to a direct relation between certain management procedures and incidence of certain health aspects. The principle that organic held animals are in better condition concerning their health as compared to conventionally held animals has not yet been proven. Well-controlled studies are needed to show the effects of organically held animals on innate and adaptive immune responses and disease susceptibility. The conditions in organic livestock production lead to novel challenges concerning social interactions, physical requirements, climatic conditions and infectious burden which requires certain breeds of animals that differ considerably from the conventionally held animals. More research is needed to identify these breeds whereby breeding selection criteria specific to organic conditions and principles should be used. A number of health problems such as infestation with parasites is an important problem that has been noted in organic livestock (poultry and pig) production and more research is needed to both prevent and treat these infections. Although largely recommended, phytotherapy and homeopathy do not have any demonstrated efficacy in managing helminths. A multidisciplinary approach is needed to address these questions. Investigations should be concerned with aspects such as rotation, stocking density, disinfections strategies, genetic predisposition and novel (plant derived or biological) antihelminthics. A major drawback in the use of phytotherapeuticals is the lack of good clinical trials, most claims are based on traditional use, anecdotal evidence or extrapolation of human data. Another problem is the consistency/standardisation of the product; variations exist in the levels of "active" ingredients between lots. Extensive studies have shown that garlic has a beneficial effect on human health and therefore would possibly be a suitable candidate to increase the health of animals in organic production. Further research is needed to substantiate this claim. Although mastitis is not seen more often in organic dairy production compared to conventional farms, it is still frequently encountered and both basic and applied research concerning prevention and cure without the traditional use of antibiotics is needed. More knowledge is needed concerning effects of alternative treatments in organic livestock production. As long as alternative treatments have not formally been proven to be effective, allopathic treatments should be preferred. Studies are needed concerning the welfare aspects of disease and insufficient or postponed treatment in organic animal production systems. It is generally accepted that feather picking and cannibalism is a major problem in organic poultry and more research is needed to counter this unwanted behaviour of the animals. The following aspects including genetic influences, housing environment, feed composition and the presence of external parasites may be involved. Vaccination has been one of the largest success factors in the prevention of disease in production animals. Most vaccines used nowadays are genetically engineered and should thus carry the GMO label. GMO based vaccines produced by incorporating genetic material from bacteria or viruses into plants is an attractive approach but does not comply with the principles of organic farming. Investigations concerning various vaccination strategies with or without GMO approaches should be evaluated to prevent various infectious diseases in organic livestock production systems. Organic livestock production leads to an increase or re-emergence of certain zoonotic diseases ( Campylobacter, toxoplasma). This is a serious drawback concerning claims that organic products are healthier as compared to conventional products and research into the prevalence of certain zoonotic infections, risk factors, farm management, post slaughter decontamination and consumer perception/education is badly needed. Several micro-organisms are described to be present in feeds and could be sources of infections of farm animals. Such pathogens can be either present on the outside of the plant (epiphytes) or on the inside of the plant (endophytes). The incidence of pathogenic bacteria in/on plants used for organic animal feed is not clear and therefore research on the incidence of these pathogens is needed. Biological cycles such as the utilisation of manure from organic farms may potentially lead to the creation of infectious reservoirs. Research is needed to provide evidence for this hypothesis and strategies should be devised to prevent this problem. Little is known about the role of pests in the occurrence of disease in organic livestock production. Research is needed into the efficacy of alternative pest control strategies since current pest control methods are not in agreement with organic production principles (use of anticoagulants for rodent control). The obligatory use of straw bedding in swine household management leads to higher dust and bioareosol (endotoxin) levels in stables. This may affect susceptibility to lung disease (farmer and animal) and investigations concerning measures to reduce dust and bioaerosol levels are needed. Current literature on this subject is not concordant and true differences may exist between management systems from different countries. Piglet mortality is an important problem in organic production systems and research concerning genetic and housing aspects is currently performed but not yet reported in the peer-reviewed literature. Amino acid imbalance and research into novel feed sources with high protein content is needed. More knowledge is known concerning possible anti-nutritive factors in these feeds and the effects of these new nutrients on gut health of the animals. Amino acid imbalance may lead to higher excretion of excess amino acids into the environment. On farm research should be performed to substantiate whether these claims also apply to organic production systems. It has been suggested that organic feeds for animals in organic production systems may contain higher mycotoxin levels thereby adversely affecting their health status. As yet no conclusive data concerning this issue has been published and research into this area is needed to prove or reject this myth. As yet it is not known whether phytase levels in organic feed for pigs are sufficient to allow optimal utilisation of organic phosphor thereby also leading to a lower environmental pollution; further investigations are needed in this area

The element of uncertainty in the interpretation of feeding experiments / 165

Cover title.Bibliography: p. 578-579