Schwanzbeißen ist eines der gravierendsten Probleme in der konventionellen Schweinehaltung, da es zu einer erheblichen Einschränkung des Tierwohls führt und zudem wirtschaftliche Einbußen nach sich zieht. Eine Prävention von Schwanzbeißen ist äußerst schwierig, da die Ursachen multifaktoriell sind. Viele Risikofaktoren, die Schwanzbeißen auslösen können, sind durch Untersuchungen hinreichend bekannt, aber das fehlende Bewusstsein für das Vorhandensein dieser Risikofaktoren auf den Betrieben erschwert es den Landwirten, eine Veränderung der Situation herbeizuführen. Ein ganzheitlicher Ansatz ist erforderlich, um die vorhandenen Risikofaktoren auf den Betrieben zu identifizieren und für jeden Betrieb ein entsprechendes individuelles Profil mit seinen Stärken und Schwächen zu erstellen. Vor diesem Hintergrund wurde das Schwanzbeiß Interventions Programm (SchwIP) 2011 entwickelt, dem eine betriebsindividuelle Erhebung verbunden mit den Grundsätzen der Planung von Tiergesundheit und Tierwohl (Animal Health and Welfare Planning, AHWP) zu Grunde liegt. SchwIP wurde auf deutschen konventionellen Betrieben mit Mastschweinehaltung angewendet und evaluiert, um Landwirten zu helfen, die Risikofaktoren für Schwanzbeißen zu identifizieren und zu reduzieren, sowie sich der Herausforderung zu stellen, die Gegebenheiten auf den Betrieben zu optimieren. Das Ziel der vorliegenden Arbeit war es zu ergründen: 1) wie eine Management-Anwendung in der Praxis verbreitet werden kann und ob ein Wissenstransfer zu den Anwendern erfolgt, 2) ob die Anwendung von SchwIP bezüglich einer Reduzierung von Risikofaktoren für Schwanzbeißen und einer Verringerung der Prävalenz von Schwanzverletzungen auf den Betrieben effektiv ist und 3) ob sich die Effektivität der Anwendung der Management-Hilfe auch in der Erfassung der Prävalenz von Schwanzverletzungen am Schlachthof widerspiegelt. Es wurden 23 eintägige Schulungen mit 19 Veterinären und 115 landwirtschaftlichen Betriebsberatern durchgeführt, um die Management-Hilfe SchwIP in ganz Deutschland zu verbreiten (Kapitel 4). Die Teilnehmer erlernten die Anwendung von SchwIP in interaktiven Schulungen mit einer Kombination aus theoretischen und praktischen Lehrabschnitten. Die Schulungsgruppen wurden subjektiv, basierend auf der Ausprägung ihrer ablehnenden Einstellung gegenüber Bestandteilen oder der Konzeption von SchwIP einer der folgenden drei Kategorien zugeordnet: hochgradig, mittelmäßig oder geringfügig ablehnend. In den nach der Schulung ausgeteilten Feedback-Bögen bewerteten hochgradig ablehnende Schulungsgruppen die Anwendbarkeit der Managementhilfe auf den Betrieben signifikant schlechter als die anderen beiden Gruppen. Allerdings wurden keine Unterschiede zwischen den Kategorien der Schulungsgruppen hinsichtlich der Benotung des Wissenstransfers in den Feedbackbögen sowie der sich an die Schulungen anschließenden praktischen Anwendungen auf den Betrieben festgestellt. Insgesamt erachteten 67% der Teilnehmer Schulungen als geeignetes Medium für das Erlernen zukünftiger Managementhilfen. Als Schlussfolgerung lässt sich ableiten, dass es erforderlich ist, sich Erfahrungen und Grundkenntnisse im Kommunikationstraining sowie in dem Leiten einer Gruppe anzueignen, bevor Schulungen entwickelt und durchgeführt werden, um auf die unterschiedlichen Einstellungen der Teilnehmenden eingehen zu können. Die Managementhilfe SchwIP wurde auf 188, von Schwanzbeißen betroffenen Betrieben, an jeweils einem Tag zwischen Juni und November im Jahr 2012 und erneut im gleichen Zeitraum im Jahr 2013 angewendet. Die Anwendung erfolgte entweder von einer Wissenschaftlerin der Arbeitsgruppe (68 Betriebe) oder von einem der 68 geschulten Tierärzte bzw. Betriebsberater (120 Betriebe) (Kapitel 5). Die Auswahl der untersuchten Buchten war problemorientiert, das heißt, Buchten wurde Vorrang in der Erhebung gegeben, in denen Schwanzbeißen zum Zeitpunkt des Besuchs vorhanden war oder Buchten, bei denen ein wiederkehrendes Auftreten bekannt war. Insgesamt zeigte sich, dass durch die Anwendung von SchwIP, bezogen auf alle Betriebe, das Gesamtrisiko zwischen den beiden Erhebungen signifikant reduziert werden konnte. Die Landwirte nahmen sich bei jedem Betriebsbesuch Ziele und Maßnahmen vor, unterstützt von dem jeweiligen Anwender und dem generierten SchwIP-Betriebsbericht, um das Risiko für Schwanzbeißen auf ihren Betrieben zu reduzieren. Der Grad der Umsetzung der vorgenommenen Maßnahmen (alle, einige oder keine Maßnahmen umgesetzt) hatte keinen signifikanten Einfluss auf die Veränderung des Gesamtrisikos von Schwanzbeißen. In den verschiedenen Risikokategorien Komfort, Beschäftigung, Futter & Wasser, Gesundheit und Stress konnte kein Unterschied im jeweiligen Gesamtrisiko der Kategorien zwischen den Erhebungen festgestellt werden. Allerdings konnte in der Kategorie Beschäftigung ein Wissenstransfer durch die Anwender und das SchwIP verzeichnet werden, da im Jahr 2013 mehr Betriebe eine Beschäftigung anboten, sowie mehr Betriebe Beschäftigungsmaterial (z. B. Stroh, Heu, etc.) anstelle von Beschäftigungsobjekten (z. B. Kette mit Holzstück) bereitstellten. Darüber hinaus zeigte sich, dass sich die Prävalenz von Schwanzläsionen (Blut am Schwanz, entzündliche Schwellungen des Schwanzes, Teil- oder Vollverlust) und von Ohrläsionen (Blut oder Kruste am Ohr) zwischen den beiden Betriebserhebungen signifikant reduzierte. Begleitend zu den Betriebserhebungen wurde eine Bonitierung der Schwanzläsionen von 32 Betrieben, auf denen das SchwIP angewendet wurde, und von 32 Kontrollbetrieben am Schlachthof durchgeführt (Kapitel 6). Drei Beobachter beurteilten Schwanzläsionen von einer Gesamtstichprobe von 80.034 geschlachteten Schweinen anhand von Fotos, wobei 43.402 Fotos von SchwIP Betrieben im Zeitraum vom 02.07.2012 bis 29.11.2013 bonitiert wurden und 36.632 Fotos von Kontrollbetrieben im Zeitraum vom 22.11.2012 bis 29.11.2013. Die Bonitur erfolgte mit Hilfe einer 4-stufigen Skala (keine / leichte / schwere Verletzung, Nekrose). Zusätzlich wurde beurteilt, ob ein Vollverlust des Schwanzes vorhanden war oder nicht. Für die Auswertung wurden die Verletzungsgrade zusammengefasst zu den Befunden ‘Verletzung‘ und ‘keine Verletzung‘. Verletzungen wurden unabhängig von dem jeweiligen Schweregrad im Durchschnitt bei 25,4 % der Schlachtkörper von Kontrollbetrieben festgestellt, wobei die Mehrzahl der Verletzungen leichte Verletzungen waren (23,6 % der Schlachtkörper). Es wurden weniger Schwanzspitzennekrosen in der routinemäßigen Fleischuntersuchung ermittelt als Nekrosen von Fotos bonitiert wurden. Von insgesamt 548 Schwanzspitzennekrosen wurden nur 17 % übereinstimmend sowohl von Fotos als auch in der routinemäßigen Fleischuntersuchung erfasst, wohingegen 53 % der Nekrosen, die in der routinemäßigen Fleischuntersuchung festgestellt wurden, auch in der Fotobonitur als solche bewertet wurden. Die Prävalenz von Schwanzverletzungen war in der ersten Saison (Winter), in der sowohl von SchwIP- als auch von Kontrollbetrieben Fotos vorhanden waren, im Beobachtungszeitraum signifikant höher bei den SchwIP-Betrieben als bei den Kontrollbetrieben, aber in keiner der folgenden Saisons. Dies weist auf eine Reduzierung durch die Anwendung der Managementhilfe SchwIP hin. Zusammenfassend erwies sich die Kombination von einer betriebsindividuellen Erhebung, entsprechend, den in SchwIP integrierten Grundsätzen der Planung von Tiergesundheit und Tierwohl (AHWP) als erfolgreich. Die Risikofaktoren für Schwanzbeißen auf Betrieben mit bestehender Schwanzbeißproblematik konnten reduziert und die Prävalenz von Schwanzverletzungen, sowohl auf den Betrieben als auch im Schlachthof, gesenkt werden. Schulungen mit Betriebsberatern und Veterinären erwiesen sich zudem als ein sehr effektiver Weg, neue Managementhilfen in der landwirtschaftlichen Praxis zu verbreiten und einen Wissenstransfer von der Wissenschaft in die Beratung und daran anschließend an die Landwirte bereitzustellen.

No description available.

Two standard graph representations for linear codes are the Tanner graph and the tailbiting trellis. Such graph representations allow the decoding problem for a code to be phrased as a computational problem on the corresponding graph and yield graph theoretic criteria for good codes. When a Tanner graph for a code is used for communication across a binary erasure channel (BEC) and decoding is performed using the standard iterative decoding algorithm, the maximum number of correctable erasures is determined by the stopping distance of the Tanner graph. Hence the computational problem of determining the stopping distance of a Tanner graph is of interest. In this thesis it is shown that computing stopping distance of a Tanner graph is NP hard. It is also shown that there can be no (1 + є ) approximation algorithm for the problem for any є > 0 unless P = NP and that approximation ratio of 2(log n)1- є for any є > 0 is impossible unless NPCDTIME(npoly(log n)). One way to construct Tanner graphs of large stopping distance is to ensure that the graph has large girth. It is known that stopping distance increases exponentially with the girth of the Tanner graph. A new elementary combinatorial construction algorithm for an almost regular LDPC code family with provable Ώ(log n) girth and O(n2) construction complexity is presented. The bound on the girth is close within a factor of two to the best known upper bound on girth. The problem of linear time exact maximum likelihood decoding of tailbiting trellis has remained open for several years. An O(n) complexity approximate maximum likelihood decoding algorithm for tail-biting trellises is presented and analyzed. Experiments indicate that the algorithm performs close to the ideal maximum likelihood decoder.

Codes can be represented by edge-labeled directed graphs called trellises, which are used in decoding with the Viterbi algorithm. We will first examine the well-known product construction for trellises and present an algorithm for recovering the factors of a given trellis. To maximize efficiency, trellises that are minimal in a certain sense are desired. It was shown by Koetter and Vardy that one can produce all minimal tail-biting trellises for a code by looking at a special set of generators for a code. These generators along with a set of spans comprise what is called a characteristic pair, and we will discuss how to determine the number of these pairs for a given code. Finally, we will look at trellis dualization, in which a trellis for a code is used to produce a trellis representing the dual code. The first method we discuss comes naturally with the known BCJR construction. The second, introduced by Forney, is a very general procedure that works for many different types of graphs and is based on dualizing the edge set in a natural way. We call this construction the local dual, and we show the necessary conditions needed for these two different procedures to result in the same dual trellis.

O objetivo deste estudo foi avaliar o efeito da densidade sobre o desempenho e o comportamento de leitões na fase de creche. Um total de 560 leitões desmamados (peso médio de 5,75 ± 0,9 kg e idade média de 20,92 ± 0,8 dias) foram aleatoriamente alojados em quatro tratamentos com diferentes densidades: T0,33, T0,28, T0,23 e T0,18 (0,33, 0,28, 0,23 e 0,18 m²/animal respectivamente). As baias continham 20 animais e a ração foi fornecida à vontade. As lesões de cauda e orelha foram graduadas em escores de 0 a 4 e o número de lesões de briga foram avaliados semanalmente. Dezesseis baias foram filmadas em três momentos (1ª, 4ª e 6ª semana de alojamento) para avaliação da frequência de brigas e de belly nosing. Foi observado um efeito linear da densidade sobre o ganho de peso diário (GPD; P=0,049), um efeito quadrático sobre o peso aos 42 dias (P=0,030) e uma tendência de efeito quadrático para o consumo médio diário (CMD; P=0,075). Não houve efeito da densidade na conversão alimentar (CA) e no coeficiente de variação (CV) do peso aos 42 dias. Foi observado um maior número de leitões apresentando lesões severas de orelha no grupo T0,18 quando comparado ao T0,33 (P = 0,019) e T0,28 (P = 0,056). Um maior número de animais com lesões moderadas ou severas foi observado no grupo T0,18 (P < 0,05) do que nos demais grupos para lesões de orelha, e do que T0,33 para lesões de cauda. Houve um efeito linear da densidade sobre a frequência de brigas, com uma maior ocorrência nos grupos com menos espaço. Contudo, não foi observado efeito sobre o número de lesões de briga ou de casos de belly nosing. Em conclusão, o aumento da densidade afetou negativamente o desempenho dos leitões, além de aumentar a ocorrência de comportamentos indesejáveis. / The aim of this study was to evaluate the effect of space allowance on performance and behavior of nursery pigs. At weaning 560 pigs (5.75 ± 0.9 kg of body weight and 20.92 ± 0.8 days of age) were randomly assigned in four treatments with different stocking densities: T0.33, T0.28, T0.23 and T0.18 (0.33, 0.28, 0.23 and 0.18 m²/pig respectively). Pens were standardized to have the same group size (20 pigs/pen) and feed was provided ad libitum. Tail and ear biting lesions and the fighting lesions were weekly observed. Sixteen pens were videotaped in three different moments (1st, 4th and 6th housing week) and the frequency of fights and belly nosing were recorded. A linear effect was observed of stocking density on average daily gain (ADG; P=0.049), a quadratic effect and a quadratic tendency of effect were observed on body weight at 42 days after weaning and on average daily feed intake (ADFI) (P=0.030; P=0.075, respectively). There was no effect of stocking density on the gain:feed ratio or weight coefficient of variation (CV) at day 42. Higher graduation of severe ear lesions was observed in pigs from T0.18 when compared to T0.33 (P = 0.0196) and T0.28 (P = 0.056). A higher number of pigs with moderate or severe tail and ear lesions was observed in T0.18 (P > 0.05). Moreover, it was observed a linear effect of density on the frequency of fights, with higher occurrence in groups housed in restricted spaces. However, no effect of stocking density was observed on fight lesions or belly nosing among treatments. In conclusion, increased density negatively affected the performance of piglets and increased the occurrence of unsuitable behaviors.

O presente trabalho avaliou a influência de lesões de caudofagia em suínos na terminação sobre o ganho de peso, variáveis sanitárias, ocorrência de lesões e condenações ao abate. O estudo foi realizado em quatro propriedades (PROP) de terminação de suínos. Para cada suíno com lesão de caudofagia foram selecionados dois controles, totalizando a avaliação dos seguintes números de animais: PROP1: 87; PROP2: 33; PROP3: 60; PROP4: 132. As lesões na cauda foram classificadas conforme o grau de severidade (escore de 0 a 4, sendo 0 normal e a severidade aumentando até os graus 2 e 3, e como grau 4 para lesões cicatrizadas). A cada uma de 4 a 6 avaliações (conforme a idade inicial do 1o diagnóstico do problema), os animais eram pesados e as lesões na cauda avaliadas. Em todas as propriedades, foi observada uma recuperação das lesões de caudofagia na terceira avaliação. Nas PROP 1 e 3, animais com lesões de escore 3 (severas) tiveram menor ganho de peso (P<0,05) comparados aos animais de escore 0. Além disso, na PROP3, animais com escore 3 foram menos pesados (P<0,05) ao abate do que aqueles de escore 0. A chance de animais com escore 3 terem artrite e apresentarem nódulos subcutâneos e/ou abscessos foi 25,5 e 30,4 vezes maior, respectivamente, em comparação aos animais com escore 0. Tanto animais com escore 2 (moderado) quanto os com escore 3 apresentaram maiores chances (P<0,05) de terem abscessos ou lesões pulmonares (pleurite e pneumonia embólica) em comparação aos animais sem lesão de cauda. Houve desvio ao Departamento de Inspeção Federal (DIF) de 21,6% (62/287) das carcaças, de animais com lesões e controles, sendo que a caudofagia foi a causa de 66,1% das condenações. Animais com lesões de escore 2 e 3 apresentaram 6,0 e 9,3 vezes maiores chances de terem suas carcaças desviadas ao DIF, respectivamente, comparados aos animais de escore 0. Os animais com lesões de caudofagia representaram 63,0% das carcaças que tiveram destino “não exportável” e 75,0% das carcaças com outros destinos. Considerando os percentuais aproximados de perdas relativas definidas pelo frigorífico visitado para as categorias de condenação (não-exportável, embutido, conserva e graxaria), isto representaria a perda de 15,58 animais (total de 18,12% entre os 86 animais que foram diagnosticados com caudofagia na granja). Isso permite concluir que, nas condições desse estudo, de cada 5 animais que são visualizados com canibalismo na terminação vai ocorrer a perda total de 1 no frigorífico. A esse prejuízo devem ser somados os animais que foram sacrificados nas granjas ou que vieram a morrer devido aos problemas causados pelas complicações das lesões na cauda. No estudo atual, foi possível determinar que, entre todos os que haviam apresentado lesões de canibalismo nas granjas, apenas dois mantinham lesões detectáveis externamente por ocasião do abate, o que pode ser explicado pela ocorrência muito precoce das lesões de caudofagia nos casos observados. Por outro lado, no abate desses animais do grupo com caudofagia, mas sem lesões externas no abate, foi observado um grande número de condenações por abscessos e lesões pulmonares. Isso sugere existir uma dicotomia entre as situações de campo e de frigorífico, reforçando a necessidade de uma melhor ligação entre esses contextos para estimar adequadamente o seu impacto. / The present work assessed the influence of tail biting lesions in finishing pigs in relation to weight gain, health, occurrence of lesions and carcass condemnation at slaughter. The study was carried out in four finishing units (PROP) and the following number of animals were assessed: PROP1: 87; PROP2: 33; PROP3: 60; PROP4: 132. To each animal with tail biting two controls were selected. Tail lesions were classified according the degrees of severity (scores from 0 to 4, 0 classified as normal and severity increasing until the degrees 2 and 3, and degree 4 meaning healed lesions). In each one of 4 to 6 visits (depending on the age of the 1st diagnosis of the problem), the animals were weighed and tail lesions assessed. In all farms, healing of tail lesions was observed in the third evaluation. In PROP 1 and 3, injured animals with score 3 showed smaller weight gain (P<0,05) when compared with animals with score 0. In PROP3, animals with score 3 were lighter (P<0,05) at slaughter than those with score 0. The chance for animals with score 3 to show arthritis and subcutaneous nodules and/or abscesses was 25,5 and 30,4 times higher, respectively, when compared with animals with score 0. Animals with scores 2 (moderate) and 3 (severe) had higher chances (P<0,05) of having abscesses or lung lesions (pleuritis and embolic pneumonia) when compared to animals without tail lesions. Trimming was observed in 21,6% (62/287) of the carcasses of injured and controls, and tail lesions corresponded to 66,1% among condemnations. Animals with lesions of scores 2 and 3 presented 6,0 and 9,3 higher chances of having trimmed carcasses, respectively, when compared with animals with score 0. Animals with tail lesion represented 63,0% of the carcasses with “non exportable” destination and 75,0% of the carcasses with other destinations. Considering the percentile of losses in each category defined by the slaughterhouse visited in this work (non exportable, processed, preserve and grease), this would represent a total loss of 15,58 animals (loss of a total of 18,82% among 86 animals with cannibalism). In the conditions of this study, this would mean that from 5 animals diagnosed with cannibalism in the finishing period, one would be totally wasted at the slaughter time. To this damage must be added the animals that were euthanazied in the herds or those died due to complications of tail injuries. In the present study, an individual diagnosis was performed in the farms of all animals with external lesions suggestive of tail cannibalism and all affected animals were followed at slaughter. Because of this, it was possible to observe that between all animals diagnosed with cannibalism at farm level, only two remained with lesions externally detectable at slaughter, what could be explained by the precocity of the lesions present in the cases analyzed by us. On the other hand, at the slaughter of this group of animals of the cannibalism group but without external lesions at slaughter, a great number of condemnations occurred by abscesses and lung lesions. This suggests that there is a dicotomy between slaughter and field situations, reinforcing the need for a better liaison between these contexts, to be able to adequately assess its impact.

In wireless communication system, convolution code has been one of the most popular error-correcting code. To prevent from the interference of noise during transmission, the transmitter usually applies convolution encode to code the processed information, and the receiver will use Viterbi decoder to decode and correct the error bit to decrease the bit error rate. In 3G mobile communication, such decoder is often applied between the base station and the communication device as a decoding mechanism. Since traditional decoders of communication devices consume more than one third power of the whole receiver, the present study focuses on the way effectively reducing the power consumption of Viterbi decoder. Traditional convolution coders use zero-tail, which make decoder be able to resist the interference of noise; however, this method would increase extra tail bits, which would decrease the code rate and affect the efficiency of transmission, especially for those information with short length, such as the header of packet. Tail-biting convolution code is another error-correcting code, which maintains the code rate, and it has been used in the control channel of LTE. Tail-biting convolution code is more complex than traditional decoder. Therefore, this thesis modifies the Wrap-Around Viterbi Algorithm (WAVA) to enormously decrease the power consuming while maintaining the bit error rate and the correctness of decoding. The aim of the present study is achieved by decreasing iteration number of WAVA algorithm to reduce one fourth of the whole power consumption. On the other hand, if the received information is not interfered by noise, it¡¦s unnecessary to turn on Tail-biting Convolution Decoder. As a result, the present study introduces the error detection circuit so that the received information can be simply decode and detected with the error detection circuit. If there is no noise interference, it can directly be outputted; if there is noise interference, however, it should be decoded by Tail-biting Convolution Decoder. The experimental results show that the survivor memory unit saves more than 60% power than traditional decoders, moreover, it will save 55%~88% power consumption when it goes with the error detection circuit. Consequently, the proposed method is indeed able to reduce the power consumption of Tail-biting Convolution Decoder. Keyword¡Gwireless communication, tail-biting convolution code, code rate, Viterbi decoder, power consumption

The objective of this research was to investigate the behavioural, physiological and immunological effects of routine surgical procedures in neonatal swine in order to provide producers with science-based recommendations. In the first experiment, low- or average-birth-weight piglets that were tail docked and ear notched at 1 or 3 days of age showed subtle differences resulting from age at processing. However, low-birth-weight male piglets had the lowest attendance during nursing bouts and spent the greatest amount of time lying alone. Vocalization data suggests that ABW piglets may be less reactive to the procedures on d 1. Overall, the decreased vitality and reduced survivability of low-birth-weight piglets suggests that delaying processing until day 3 for these piglets may be preferable. In the second experiment, the effects of docked tail length and nursery stocking density on tail-biting behaviour, skin lesions and rectal prolapses were investigated. Long-tailed pigs (docked to 4.5 cm at birth) were most vulnerable to tail-biting, and housing at a moderate versus high nursery stocking density was not sufficient to reduce tail-biting. High nursery stocking density negatively impacted skin lesion scoring and growth performance for the majority of the grower-finisher period. Pigs from either nursery stocking density and docked tail length groups were equally likely to be affected by prolapsed rectal mucosa. Given the decreased survivability and significantly lighter weaning weight for low-birth-weight piglets compared to those of average-birth-weight, delaying processing of low-birth-weight piglets may be the most humane option. Further, until tail-biting is better understood and a more effective solution found, the routine docking of tails remains the optimal method for balancing a situation with enormous welfare-reducing potential. / Agriculture and Agri-Food Canada

O objetivo deste estudo foi avaliar o efeito da densidade sobre o desempenho e o comportamento de leitões na fase de creche. Um total de 560 leitões desmamados (peso médio de 5,75 ± 0,9 kg e idade média de 20,92 ± 0,8 dias) foram aleatoriamente alojados em quatro tratamentos com diferentes densidades: T0,33, T0,28, T0,23 e T0,18 (0,33, 0,28, 0,23 e 0,18 m²/animal respectivamente). As baias continham 20 animais e a ração foi fornecida à vontade. As lesões de cauda e orelha foram graduadas em escores de 0 a 4 e o número de lesões de briga foram avaliados semanalmente. Dezesseis baias foram filmadas em três momentos (1ª, 4ª e 6ª semana de alojamento) para avaliação da frequência de brigas e de belly nosing. Foi observado um efeito linear da densidade sobre o ganho de peso diário (GPD; P=0,049), um efeito quadrático sobre o peso aos 42 dias (P=0,030) e uma tendência de efeito quadrático para o consumo médio diário (CMD; P=0,075). Não houve efeito da densidade na conversão alimentar (CA) e no coeficiente de variação (CV) do peso aos 42 dias. Foi observado um maior número de leitões apresentando lesões severas de orelha no grupo T0,18 quando comparado ao T0,33 (P = 0,019) e T0,28 (P = 0,056). Um maior número de animais com lesões moderadas ou severas foi observado no grupo T0,18 (P < 0,05) do que nos demais grupos para lesões de orelha, e do que T0,33 para lesões de cauda. Houve um efeito linear da densidade sobre a frequência de brigas, com uma maior ocorrência nos grupos com menos espaço. Contudo, não foi observado efeito sobre o número de lesões de briga ou de casos de belly nosing. Em conclusão, o aumento da densidade afetou negativamente o desempenho dos leitões, além de aumentar a ocorrência de comportamentos indesejáveis. / The aim of this study was to evaluate the effect of space allowance on performance and behavior of nursery pigs. At weaning 560 pigs (5.75 ± 0.9 kg of body weight and 20.92 ± 0.8 days of age) were randomly assigned in four treatments with different stocking densities: T0.33, T0.28, T0.23 and T0.18 (0.33, 0.28, 0.23 and 0.18 m²/pig respectively). Pens were standardized to have the same group size (20 pigs/pen) and feed was provided ad libitum. Tail and ear biting lesions and the fighting lesions were weekly observed. Sixteen pens were videotaped in three different moments (1st, 4th and 6th housing week) and the frequency of fights and belly nosing were recorded. A linear effect was observed of stocking density on average daily gain (ADG; P=0.049), a quadratic effect and a quadratic tendency of effect were observed on body weight at 42 days after weaning and on average daily feed intake (ADFI) (P=0.030; P=0.075, respectively). There was no effect of stocking density on the gain:feed ratio or weight coefficient of variation (CV) at day 42. Higher graduation of severe ear lesions was observed in pigs from T0.18 when compared to T0.33 (P = 0.0196) and T0.28 (P = 0.056). A higher number of pigs with moderate or severe tail and ear lesions was observed in T0.18 (P > 0.05). Moreover, it was observed a linear effect of density on the frequency of fights, with higher occurrence in groups housed in restricted spaces. However, no effect of stocking density was observed on fight lesions or belly nosing among treatments. In conclusion, increased density negatively affected the performance of piglets and increased the occurrence of unsuitable behaviors.

O presente trabalho avaliou a influência de lesões de caudofagia em suínos na terminação sobre o ganho de peso, variáveis sanitárias, ocorrência de lesões e condenações ao abate. O estudo foi realizado em quatro propriedades (PROP) de terminação de suínos. Para cada suíno com lesão de caudofagia foram selecionados dois controles, totalizando a avaliação dos seguintes números de animais: PROP1: 87; PROP2: 33; PROP3: 60; PROP4: 132. As lesões na cauda foram classificadas conforme o grau de severidade (escore de 0 a 4, sendo 0 normal e a severidade aumentando até os graus 2 e 3, e como grau 4 para lesões cicatrizadas). A cada uma de 4 a 6 avaliações (conforme a idade inicial do 1o diagnóstico do problema), os animais eram pesados e as lesões na cauda avaliadas. Em todas as propriedades, foi observada uma recuperação das lesões de caudofagia na terceira avaliação. Nas PROP 1 e 3, animais com lesões de escore 3 (severas) tiveram menor ganho de peso (P<0,05) comparados aos animais de escore 0. Além disso, na PROP3, animais com escore 3 foram menos pesados (P<0,05) ao abate do que aqueles de escore 0. A chance de animais com escore 3 terem artrite e apresentarem nódulos subcutâneos e/ou abscessos foi 25,5 e 30,4 vezes maior, respectivamente, em comparação aos animais com escore 0. Tanto animais com escore 2 (moderado) quanto os com escore 3 apresentaram maiores chances (P<0,05) de terem abscessos ou lesões pulmonares (pleurite e pneumonia embólica) em comparação aos animais sem lesão de cauda. Houve desvio ao Departamento de Inspeção Federal (DIF) de 21,6% (62/287) das carcaças, de animais com lesões e controles, sendo que a caudofagia foi a causa de 66,1% das condenações. Animais com lesões de escore 2 e 3 apresentaram 6,0 e 9,3 vezes maiores chances de terem suas carcaças desviadas ao DIF, respectivamente, comparados aos animais de escore 0. Os animais com lesões de caudofagia representaram 63,0% das carcaças que tiveram destino “não exportável” e 75,0% das carcaças com outros destinos. Considerando os percentuais aproximados de perdas relativas definidas pelo frigorífico visitado para as categorias de condenação (não-exportável, embutido, conserva e graxaria), isto representaria a perda de 15,58 animais (total de 18,12% entre os 86 animais que foram diagnosticados com caudofagia na granja). Isso permite concluir que, nas condições desse estudo, de cada 5 animais que são visualizados com canibalismo na terminação vai ocorrer a perda total de 1 no frigorífico. A esse prejuízo devem ser somados os animais que foram sacrificados nas granjas ou que vieram a morrer devido aos problemas causados pelas complicações das lesões na cauda. No estudo atual, foi possível determinar que, entre todos os que haviam apresentado lesões de canibalismo nas granjas, apenas dois mantinham lesões detectáveis externamente por ocasião do abate, o que pode ser explicado pela ocorrência muito precoce das lesões de caudofagia nos casos observados. Por outro lado, no abate desses animais do grupo com caudofagia, mas sem lesões externas no abate, foi observado um grande número de condenações por abscessos e lesões pulmonares. Isso sugere existir uma dicotomia entre as situações de campo e de frigorífico, reforçando a necessidade de uma melhor ligação entre esses contextos para estimar adequadamente o seu impacto. / The present work assessed the influence of tail biting lesions in finishing pigs in relation to weight gain, health, occurrence of lesions and carcass condemnation at slaughter. The study was carried out in four finishing units (PROP) and the following number of animals were assessed: PROP1: 87; PROP2: 33; PROP3: 60; PROP4: 132. To each animal with tail biting two controls were selected. Tail lesions were classified according the degrees of severity (scores from 0 to 4, 0 classified as normal and severity increasing until the degrees 2 and 3, and degree 4 meaning healed lesions). In each one of 4 to 6 visits (depending on the age of the 1st diagnosis of the problem), the animals were weighed and tail lesions assessed. In all farms, healing of tail lesions was observed in the third evaluation. In PROP 1 and 3, injured animals with score 3 showed smaller weight gain (P<0,05) when compared with animals with score 0. In PROP3, animals with score 3 were lighter (P<0,05) at slaughter than those with score 0. The chance for animals with score 3 to show arthritis and subcutaneous nodules and/or abscesses was 25,5 and 30,4 times higher, respectively, when compared with animals with score 0. Animals with scores 2 (moderate) and 3 (severe) had higher chances (P<0,05) of having abscesses or lung lesions (pleuritis and embolic pneumonia) when compared to animals without tail lesions. Trimming was observed in 21,6% (62/287) of the carcasses of injured and controls, and tail lesions corresponded to 66,1% among condemnations. Animals with lesions of scores 2 and 3 presented 6,0 and 9,3 higher chances of having trimmed carcasses, respectively, when compared with animals with score 0. Animals with tail lesion represented 63,0% of the carcasses with “non exportable” destination and 75,0% of the carcasses with other destinations. Considering the percentile of losses in each category defined by the slaughterhouse visited in this work (non exportable, processed, preserve and grease), this would represent a total loss of 15,58 animals (loss of a total of 18,82% among 86 animals with cannibalism). In the conditions of this study, this would mean that from 5 animals diagnosed with cannibalism in the finishing period, one would be totally wasted at the slaughter time. To this damage must be added the animals that were euthanazied in the herds or those died due to complications of tail injuries. In the present study, an individual diagnosis was performed in the farms of all animals with external lesions suggestive of tail cannibalism and all affected animals were followed at slaughter. Because of this, it was possible to observe that between all animals diagnosed with cannibalism at farm level, only two remained with lesions externally detectable at slaughter, what could be explained by the precocity of the lesions present in the cases analyzed by us. On the other hand, at the slaughter of this group of animals of the cannibalism group but without external lesions at slaughter, a great number of condemnations occurred by abscesses and lung lesions. This suggests that there is a dicotomy between slaughter and field situations, reinforcing the need for a better liaison between these contexts, to be able to adequately assess its impact.