Injurious tail biting in pigs: How can it be controlled in existing systems without tail docking?

Tail biting is a serious animal welfare and economic problem in pig production. Tail docking, which reduces but does not eliminate tail biting, remains widespread. However, in the EU tail docking may not be used routinely, and some 'alternative' forms of pig production and certain countries do not allow tail docking at all. Against this background, using a novel approach focusing on research where tail injuries were quantified, we review the measures that can be used to control tail biting in pigs without tail docking. Using this strict criterion, there was good evidence that manipulable substrates and feeder space affect damaging tail biting. Only epidemiological evidence was available for effects of temperature and season, and the effect of stocking density was unclear. Studies suggest that group size has little effect, and the effects of nutrition, disease and breed require further investigation. The review identifies a number of knowledge gaps and promising avenues for future research into prevention and mitigation. We illustrate the diversity of hypotheses concerning how different proposed risk factors might increase tail biting through their effect on each other or on the proposed underlying processes of tail biting. A quantitative comparison of the efficacy of different methods of provision of manipulable materials, and a review of current practices in countries and assurance schemes where tail docking is banned, both suggest that daily provision of small quantities of destructible, manipulable natural materials can be of considerable benefit. Further comparative research is needed into materials, such as ropes, which are compatible with slatted floors. Also, materials which double as fuel for anaerobic digesters could be utilised. As well as optimising housing and management to reduce risk, it is important to detect and treat tail biting as soon as it occurs. Early warning signs before the first bloody tails appear, such as pigs holding their tails tucked under, could in future be automatically detected using precision livestock farming methods enabling earlier reaction and prevention of tail damage. However, there is a lack of scientific studies on how best to respond to outbreaks: the effectiveness of, for example, removing biters and/or bitten pigs, increasing enrichment, or applying substances to tails should be investigated. Finally, some breeding companies are exploring options for reducing the genetic propensity to tail bite. If these various approaches to reduce tail biting are implemented we propose that the need for tail docking will be reduced. © 2014 The Animal Consortium.

Development of Zero Water Exchange Shrimp Culture System Integrated With Bioremediation of Detritus and Ammonia- Nitrogen

Aquaculture is one of the fastest growing food sectors in the world. Amongst the various branches of aquaculture, shrimp culture has expanded rapidly across the globe because of its faster growth rate, short culture period, high export value and demand in the International market. Indian shrimp farming has experienced phenomenal development over the decades due to its excellent commercial viability. Farmers have adopted a number of innovative technologies to improve the production and to maximize the returns per unit area. The culture methods adopted can be classified in to extensive, modified extensive and semi intensive based on the management strategies adopted in terms of pond size, stocking density, feeding and environmental control. In all these systems water exchanges through the natural tidal effects, or pump fed either from creek or from estuaries is a common practice. In all the cases, the systems are prone to epizootics due to the pathogen introduction through the incoming water, either brought by vectors, reservoir hosts, infected tissue debris and free pathogens themselves. In this scenario, measures to prevent the introduction of pathogen have become a necessity to protect the crop from the onslaught of diseases as well as to prevent the discharge of waste water in to the culture environment.The present thesis deals with Standardization of bioremediation technology for zero water exchange shrimp culture system

Exploratory and dust-bathing behaviour in laying hens kept in commercial aviaries and furnished cages

The aim of the present thesis was to identify management factors that affect the extent of exploratory behaviour (ground pecking, scratching) as well as quantitative and qualitative as-pects of dust-bathing behaviour in laying hens kept in commercial furnished cages (‘small group housing’) and aviaries. Based on the results, it should be considered which management measures can be recommended for farmers to enhance hen welfare. The feasibility of direct observations of dust-bathing behaviour as well as video observations of exploratory and dust-bathing behaviour was tested in two aviaries. The direct observations were judged to be unfeasible under the conditions encountered. For the analysis of the video recordings, different sampling intervals for instantaneous scan sampling, different extents of observation time, and intra- and inter-observer reliabilities were compared and the most ap-propriate observation scheme selected. Applying the selected scheme (observing the first 16 minutes of every hour distributed over two consecutive light days with a sample interval of two minutes), within the range of environmental conditions found in 22 aviaries, pecking, scratching and dust-bathing behaviour was performed on average 25, 2 and 7 % of the obser-vation time. Hen numbers in the litter were positively associated with stocking density and group size. More scratching was performed with increasing litter height as well as in humid litter. If no litter had been provided, thus substrate consisted of dust and faeces, a reduced proportion of dust-bathing was found. The same method was then used in 16 furnished cage systems. On average 12 % of the total hen number were found on the scratching mats. The hens spent 8 % of the observed time pecking at the mat, 4 % dust-bathing and 0.4 % scratch-ing. Higher proportions were found on the mats and more dust-bathing behaviour occurred, if substrate was provided. Also with increasing light intensity and stocking density more hens were observed on the mats. More pecking and scratching occurred in conditions of higher stocking density, probably due to social facilitation, and of increased mat area per hen. With increasing mat numbers per cage less pecking was observed. Wider mats led to increased dust-bathing behaviour. Finally, 129 dust-baths recorded in 17 aviaries were analysed in detail. On average they lasted 17 minutes, with the tossing phase taking 69 % of this time, including on average 2 vertical wing shakes and 3 scratches with one leg per minute tossing phase. Dust-bath duration de-creased with increasing litter height. Litter type influenced all recorded parameters: dust-bath duration was highest on straw and lowest on fine material and fine material mixed with straw, where on both also the proportion of the tossing phase was lowest. The number of vertical wing shakes during the dust-bath was highest on straw and lowest on fine material mixed with straw as against the frequency of vertical wing shaking that was lowest on straw and highest on fine material. If dust-bathing hens were disturbed twice or more, dust-bathing duration decreased. With increasing light intensity a decreased proportion of the tossing phase as well as a reduced number of vertical wing shakes were recorded. Possibly the light stimulated the hens to dust-bath more often with less tossing behaviour per performance. The observed variation of the dust-bathing parameters could reflect successful adaptation or frustration of the hens. The litter and light conditions on the investigated farms were predominantly restrictive in terms of stimulation of exploration and dust-bathing behaviour. Thus, it was only possible to analyse possible associations between these factors and exploration and dust-bathing behav-iour within the range found. Based on the results the following management recommendations can be given: To allow hens in furnished cages more normal activity, substrate availability should be improved and mat space and light intensity increased. With regard to aviaries as well litter availability should be improved. Litter height should not be too low. Disturbances during dust-bathing should be prevented, but no influencing factors could be identified.

Utilização de embriões liofilizados e flocos de Artemia na diversificação nutricional de pós-larvas do camarão marinho Litopenaes vannamei (Boone, 1931)

The objective of the current study was to evaluate the zootechnical performance (survival and growth) of Litopenaeus vannamei post-Iarvae fed an artificial shrimp diet supplemented with Artemia flakes or freeze-dried Artemia embryos. For that purpose, 20 culturing units were individually stocked with 50 shrimp post-Iarvae (average dry weight of 0,3 ± 0,03 mg) at a stocking density of 20 post-larvae per liter, and fed the experimental diets to satiation during 20 days. The experimental design consisted of four diets (T1, T2, T3 and T4) with five repetitions each. For treatments T1, T2 and T3, dietary supplements of 5mg of Artemia flakes (T1), freeze-dried Artemia embryos (T2), and of the commercial shrimp diet (T3) were offered 2 hours after the shrimp were initially fed the commercial shrimp diet. For treatment T4 (control), no additive was offered 2 hours after the initial feeding. Shrimp survival, absolut (GPA) and relative increase in weight (GPR), and specific growth rate (TCR) were used as evaluation criteria. After the experimental period, no significant statistical differences (p>0,05) in survival were observed. Regarding growth, the dietary treatment which used freeze-dried Artemia embryos as an additive (T2) presented the best results for GPA (6,7 ± 0,7 mg). There were no statistical differences within treatments T1, T3 and T4 (p>0,05). AIso, post-larvae fed freeze-dried embryos (T2) showed a relative increase in weight (2241,4%) which differed significantly (p<0,05) from T4(1911,7%) but not from T1 (1801,6%) or T3 (1946,7%). In conclusion, the results of the current study indicate that an artificial shrimp diet supplemented with freeze-dried Artemia embryos fulfils the nutritional requirements of post-larvae L. vannamei and promotes a better growth than diets not supplemented with Artemia flakes

Influência de fatores ambientais na incidência do vírus da infecção hipodermal e necrose hematopoiética (IHHNV) no camarão Litopenaeus vannamei cultivado em fazendas do Estado do Rio Grande do Norte (RN)

The shrimp farming industry is the most profitable area of the aquaculture at Rio Grande do Norte (RN) state, which is one of the largest producers in Brazil. However the infections that affect the shrimp cause major economic losses. The infection is a result of the interaction between the shrimp, the environment and pathogen. The change of these factors may lead to a condition of stress and susceptibility to opportunistic infections. One of these infections caused by Infectious Hypodermal and Hematopoietic Necrosis Virus (IHHNV) is widely distributed in several countries and affects a wide range of hosts. To optimize conditions for production of Litopenaeus vannamei shrimp, the more species cultivated in Brazil, it is necessary to understand the effects of environmental factors in the susceptibility of this species to infections. The aim of this study was to determine the IHHNV prevalence and to investigate the influence of environmental factors as salinity, temperature, stocking density, dissolved oxygen and rainfall in the IHHNV incidence in L. vannamei grown in farms, in the RN state. To determine the IHHNV prevalence were used 1089 samples of L. vannamei collected in seven farms. To perform the study about the influence of environmental factors, 525 samples of L. vannamei shrimp were collected in eight farms located in regions of low (0-1 ), medium (21-30 ) and high (38-57 ) salinity, using extensive (≤15 shrimp/m2 ), semi-intensive (18-33 shrimp/m2) or intensive (>36 shrimp/m2) stocking density systems. The IHHNV infection was determined in pleopod and hemolymph using the polymerase chain reaction (PCR). The environmental factors were recorded during the collection of animals, using a refractometer to measure the salinity and a multi-parameter meter to measure the temperature and concentration of dissolved oxygen in the water. The IHHNV prevalence in RN was 43% (468 infected shrimp out of 1089), varying on different farms. On the seven farms studied, IHHNV prevalence ranged from 18.6% to 54.8%. The infection rates in the shrimp cultured in low, medium and high salinity were respectively 43.10% (125/290), 31.2% (15/48) and 24.6% (46/187) and was significantly higher in shrimp grown in low salinity (P<0.001). The infection rates in ponds of extensive, semi-intensive and intensive systems were respectively, 28.7%, 28.28% and 47.84%, and was significantly higher in high stocking densities (P<0.001). This study indicated a high IHHNV prevalence and a significant effect of salinity and stocking density, but not of the temperature, rainfall and dissolved oxygen on the IHHNV infection rate in the L. vannamei shrimp cultured in the northeastern Brazil

Efeito da salinidade, densidade de estocagem e da infecção hipodermal e necrose hematopoiética (IHHN) na imunidade do camarão Litopenaeus vannamei cultivados em fazendas do Rio Grande do Norte

The main problem faced by the shrimp industry are the infectious diseases. The hypodermal and hematopoietic necrosis infection (IHHN) is one of the major cause of disease in the cultured shrimp, Litopenaeus vannamei. Environmental changes involving water quality, oxygen concentration, salinity, temperature, stocking density, presence of pathogens, among others, triggering a stressing condition for the cultured shrimp, weakening them and allowing the outbreak of diseases. The stress on the animal leads to a change in the molecules immune response components, which can be used as indicators of shrimp health. Thus, the objective of the present study was to evaluate the effect of salinity, stocking density and IHHNV infection on the L. vannamei shrimp. The immune parameters used to check the shrimp health were the total hemocytes counts (THC), the agglutinating activity (AA) and the clotting time (CT) of the serum of shrimp. These parameters were analyzed in healthy and IHHNV-infected shrimp, grown in low (0-0.5 ), medium (19-24 ) and high (> 38 ) salinity, and extensive (7-12 cam.m-2), semi-intensive (15-25 cam.m-2) and intensive (33-45 cam.m -2) stocking density. The IHHNV infection rate was significantly higher in low salinity (P<0.005) and intensive density (P<0.005), both stressful conditions for L. vannamei. Low salinity significantly increased THC (P<0.05) and decreased and CT (P<0.05) in healthy and infected shrimp, but AA (P<0.05) significantly decreased in healthy shrimp at medium salinity. Culture intensification did not affect the THC, AA and CT of healthy and infected shrimp (P>0.05). The IHHNV infection did not affect any immune parameters of shrimp cultured at different salinities and stocking densities. It is necessary to emphasize that this study was conducted in shrimp grown in ponds, where several environmental factors are acting simultaneously. Thus, further studies are needed about the influence of other environmental factors on the immune parameters of shrimp cultured in pond

Dynamics of some limnological characteristics in pacu (Piaractus mesopotamicus) culture tanks as function of handling

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Custos e rentabilidade da produção de juvenis de tilápia-do-nilo em tanques-rede utilizando-se diferentes densidades de estocagem

Neste trabalho foi realizada a análise econômica da produção de juvenis de tilápia-do-nilo em tanques-rede utilizando-se diferentes densidades de estocagem. O experimento foi desenvolvido em área aquícola, em delineamento de blocos casualizados, com quatro densidades de estocagem (100, 200, 300 e 400 peixes m-3), avaliadas com seis repetições, em dois períodos de criação: de março a abril de 2005 (52 dias - peso inicial de 43,08 ± 2,98 g e peso final de 262,14 ± 47,86 g) e de março a abril de 2006 (58 dias - peso inicial de 43,16 ± 5,34 g e peso final 314,24 ± 73,30 g). Foram avaliadas as seguintes variáveis econômicas: custo da ração mais custo do juvenil dividido pela biomassa, em R$ kg-1; porcentagem do custo da ração por quilo de peixe produzido sobre o preço de venda; porcentagem do custo do juvenil por quilo de peixe produzido sobre o preço de venda e; porcentagem dos custos da ração mais do juvenil por quilo de peixe produzido sobre o preço de venda. da menor densidade de estocagem (100) para a maior (400), ocorreu diminuição no ganho de peso diário e elevação do índice de conversão alimentar aparente, mas essa redução não comprometeu a taxa de sobrevivência. Entretanto, o ganho de biomassa aumentou com o adensamento de peixes. As maiores receitas líquidas foram obtidas nas densidades de estocagem de 100 e 200 peixes m-3. Os preços não remuneraram os custos operacionais (efetivo e total) em maiores densidades (300 e 400 peixes m-3). Os melhores resultados para a produção de juvenis de tilápia-do-nilo foram obtidos com densidades de até 200 peixes m-3.

Effect of intensification on grow out of the Amazon River prawn, Macrobrachium amazonicum

The effects of intensification on growth, survival, productivity, population structure, and distribution of harvested biomass in individual size classes of Macrobrachium amazonicum in semi-intensive culture were evaluated. Postlarvae (0.01 g) were stocked in 12 ponds at densities of 10, 20, 40, and 80/m(2) (three replicates per treatment) and raised for 5.5 mo. Average individual weight significantly decreased and productivity significantly increased as stocking density increased (P < 0.001), while survival was not affected (P > 0.05). Prawn mean weight at harvest ranged from 3.6 (80/m(2)) to 7.0 g (10/m(2)). Average survival ranged from 65.5% (40/m(2)) to 72.8% (20/m(2)), while productivity ranged from 508 (10/m(2)) to 2051 kg/ha (80/m(2)). Harvested biomass showed a clear bimodal distribution in individual size classes indicating the occurrence of heterogeneous growth, which may affect management and market strategies. Harvested biomass of prawns weighing more than 7 g (the best market size) increases for stocking densities up to 40/m(2) and stabilizes between 40 and 80/m(2). Growth reduction was associated with a decreasing frequency and average weight of green claw 1 and green claw 2 male morphotypes and adult females as density increased. Thus, the distribution of male morphotypes and sexually mature females are affected by density-dependent factors. Results suggest that prawn density plays an important role on M. amazonicum grow-out phase, as has been demonstrated for other species of the genus Macrobrachium. M. amazonicum tolerates grow-out intensification and may be raised in both semi-intensive and intensive systems stocked at very high densities yielding high productivity.

Ontogenetic Variation in Ammonia Excretion during the Early Life Stages of the Amazon River Prawn, Macrobrachium amazonicum

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito do isolamento térmico de telhado sobre o desempenho de frangos de corte alojados em diferentes densidades

O objetivo deste trabalho foi avaliar o efeito do uso de isolante térmico de telhado instalado como forro sob a cobertura no desempenho de frangos alojados em diferentes densidades (10, 16 e 22 aves/m²) e nas características da cama de aviário em galpão convencional. O experimento foi realizado durante o verão, utilizando 3328 aves da linhagem Hubbard, distribuídas em um delineamento inteiramente casualizado, em um esquema fatorial 3x2 (densidade e sexo), com quatro repetições dentro de cada ambiente. Para a comparação dos ambientes, utilizou-se a análise conjunta. Durante o período experimental, registraram-se dados de temperatura ambiente em vários pontos do galpão e em diversos horários, umidade relativa e carga térmica radiante. O teor de nitrogênio e matéria seca e a temperatura da cama foram determinados. No ambiente com isolante térmico, as temperaturas ambientais médias e a amplitude térmica diária foram menores e a umidade relativa do ar, maior. O desempenho das aves foi melhor no ambiente com isolante térmico, no qual as aves tiveram maior consumo de ração, maior ganho de peso, melhor conversão alimentar, menor mortalidade e maior produção por área. A temperatura retal das aves do ambiente sem isolante térmico foi mais elevada. À medida que se elevou a densidade, a mortalidade aumentou, porém a produção por área foi maior. O uso do isolante não influenciou a produção de cama, mas diminuiu a porcentagem de nitrogênio na cama. Com o aumento da densidade, a produção de cama elevou-se, pelo maior volume de excretas, mas não influenciou sua porcentagem de nitrogênio. O uso do isolante térmico permitiu aumento da densidade de criação dos frangos.

Gonadal steroids levels and vitellogenesis in the formation of oocytes in Prochilodus lineatus (Valenciennes) (Teleostei: Characiformes)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Vitamin C and endogenous cortisol in foreign-body inflammatory response in pacus

O objetivo deste trabalho foi avaliar o efeito da suplementação com vitamina C no aumento da atividade de macrófagos e células gigantes multinucleadas (CGM), em pacus mantidos em duas densidades de estocagem. O experimento foi realizado em parcelas subdivididas, em arranjo fatorial 2x2x3 com: 0 e 500 mg kg-1 de vitamina C; densidade de estocagem de 5 e 20 kg m-3; e tempos de avaliação de 3, 6 e 12 dias após o implante subcutâneo (DPI) de lamínulas de vidro. Foram determinados o número de macrófagos e de CGM, bem como os níveis de cortisol e glicose no plasma. O número de macrófagos e de CGM com 2 a 5 núcleos foi significativamente maior nos peixes suplementados com vitamina C, à densidade 5 kg m-3, aos 3 DPI, em relação aos não suplementados. Constatou-se menor quantidade de macrófagos e CGM em peixes com baixa concentração plasmática de cortisol. A suplementação com 500 mg de vitamina C por quilograma de ração beneficia a atividade de macrófagos em inflamações do tipo corpo estranho, e a elevada concentração de cortisol circulante tem efeito supressor nesta resposta.

Análise de efluente e histologia da pele, fígado e rim de Pacus (Piaractus mesopotamicus) suplementados com cromo trivalente

The objective of this work was to evaluate the skin, liver and kidney histology of young pacus supplemented in diet with trivalent chromium and to evaluate the residue of chromium in water effluent. Randomised delineation by using factorial scheme 4x2, with four levels of chromium (0, 6, 12, 18 mg/L), two stocking densities (4 and 20 kg/m(3)), and four repetitions were used. Pacus with 100 g were used, for 90 days. An increase of the number of mucus cells and club cells in the epidermis of the pacus supplemented with 18 chromium mg/kg was observed in any stocking density. The same effect was observed in the liver, and in the highest density (20 kg/m(3)) the alterations already occurred at the level of 6 mg/kg with the inclusion of chromium, initially with congestion of sinusoids and getting worse at the level of 18 mg/kg with necrosis. The kidney didn't present visible morphologic alterations when supplemented and submitted to the stocking densities. The concentration of chromium in the effluent of pacus was 3.27 mu g/L in the higher level of supplementation (18 mg/L). In conclusion the level of 18 supplement mg/kg was not shown beneficial to the growth of pacus and the stocking density, due to the possible stress, accelerated the alteration histology process of tissues.

Efeitos do substrato e da densidade populacional sobre as atividades comportamentais e níveis de homócitos em relação à densidade em Litopenaeus vannamei (BOONE, 1931)

Carciniculture in Brazil occupies world-wide prominence due to shrimp culture, and the state of Rio Grande do Norte has presented the best results in the culture of the Litopenaeus vannamei in the last decade. This species has been shown to adapt easily to different environments and is between the five most cultivated penaeids of the world. The ponds are usually constructed in areas close to water courses and estuaries. Stock density and substrate ponds can pollute environment, causing losses in the growth and survival of the shrimps, being considered stress factors. Shrimps in inadequate densities and substrates can result reduced productivity of the farm; and favor diseases. So, it is important to verify how these variables influence the development of the animals in the culture farms. Our objective was to study the influence of the type of substrate and the stock density on the behavior and haemocyte count of the L. vannamei. Individually marked juvenile shrimps were kept in aquaria with 30 L of seawater and continuous aeration, in 12L-12D photoperiod. They were observed through Ad libitum and focal sampling instantaneous methods during thirty days, five times per week, six times per day (8:00 to 18:00) in windows of 15 minutes every two hours. The marking of carapace permitted quantifying molting and the feeding was supplied three times a day. Two experiments were carried out: the first one tested animals in the three different substrates (fine sand, smaller rocks-SPP and biggest rocks-SGR) with 33 shrimp/m2. In the second one, the animals were tested in three stock densities (26, 52 and 66 shrimp/m2) in fine sand substrate. At the end of experiment, biometry (first and second ones) and haemocyte count (second one) were made. The behavior of the L. vannamei seems to have been influenced by substrate and stocking density. In low granulometry of the substrate; the exploratory behavior became more frequent and inactivity of the shrimps was reduced. Burrowing was registered in sand substrate, specially in the initial period of the day. Cleaning was gradually higher along the day, presenting the biggest levels as the dark phase approached. The ingestion of feeding was more frequent in low density, and the animals were bigger and heavier at the end of the experiment. In the fine sand condition, the animals presented better growth, probably associated with the burrowing. The molting was equivalent in all types of substrate, but it was more frequent in high densities. Mortality of the shrimps was more frequent in high densities, and cannibalism and diseases were also registered in that condition. The clinical signals were similar to the ones of infectious mionecrosis (IMNV), generally associated with environment and physical stress. The haemocyte count was low for the hematologic standards of the penaeid, which we attributed for greater dilution of haemolymph in the postmolting phase. Smaller shrimps presented lower levels of haemocytes in relation to the bigger animals, count was also low in 26 shrimp/m2 density. The study demonstrates that stocking density and the granulometry of the substrate can affect the welfare, the health and the behavior of the L. vannamei. The sand substrate and low stocking density can be important tools in the management systems of shrimp production