The slaughtening causes with dental and gingival lesions in dairy cows within postmortem period

Background: A regular and balanced feeding is essential for the animals in order to maintain their normal physiological function and be productive at the desired level. Digestion activities start with chewing in the mouth and the healthy dental arch is needed to perform a complete chewing function. Abnormal dental development and other dental pathologies impair digestive functions by negatively affecting chewing functions. The aim of the present study was to classified dental anomalies, dental degenerations, dental and gingival lesions seen in dairy cows and was aimed to reveal these lesions and depending on these disorders the reasons for slaughtering in dairy cows.Materials, Methods & Results: The material of this study consists of 600 dairy cows, being slaughtered for a year, and 170 dairy cows, detected dental anomalies, dental degenerations and dental-gingival lesions in the postmortem examination. Detailed macroscopic and radiological examinations of mandibles and maxillae of the dairy cows with dental and gingival lesions in postmortem examination were performed. The detailed information of the cases, such as: age, race, breeding, living region and slaughtering causes, etc. of dairy cows, suffering from dental lesions was recorded from slaughterhouse data access. In this study, 87 cases (51.18%) of the determined dental lesions were defined as dental degeneration, 34 cases (20%) as caries, 30 cases (17.64%) as dental abnormalities in the formation and dental arch and 19 cases (11.18%) as periodontal inflammation.[...]

The slaughtening causes with dental and gingival lesions in dairy cows within postmortem period

Background: A regular and balanced feeding is essential for the animals in order to maintain their normal physiological function and be productive at the desired level. Digestion activities start with chewing in the mouth and the healthy dental arch is needed to perform a complete chewing function. Abnormal dental development and other dental pathologies impair digestive functions by negatively affecting chewing functions. The aim of the present study was to classified dental anomalies, dental degenerations, dental and gingival lesions seen in dairy cows and was aimed to reveal these lesions and depending on these disorders the reasons for slaughtering in dairy cows.Materials, Methods & Results: The material of this study consists of 600 dairy cows, being slaughtered for a year, and 170 dairy cows, detected dental anomalies, dental degenerations and dental-gingival lesions in the postmortem examination. Detailed macroscopic and radiological examinations of mandibles and maxillae of the dairy cows with dental and gingival lesions in postmortem examination were performed. The detailed information of the cases, such as: age, race, breeding, living region and slaughtering causes, etc. of dairy cows, suffering from dental lesions was recorded from slaughterhouse data access. In this study, 87 cases (51.18%) of the determined dental lesions were defined as dental degeneration, 34 cases (20%) as caries, 30 cases (17.64%) as dental abnormalities in the formation and dental arch and 19 cases (11.18%) as periodontal inflammation.[...](AU)

Malformações em pequenos ruminantes no semiárido da Bahia: aspectos epidemiológicos, clínico-patológicos e radiológicos / Malformations in small ruminants in the semi-arid region of Bahia: epidemiological, clinical-pathological and radiological aspects

O objetivo do presente trabalho é descrever os principais aspectos epidemiológicos, clínico-patológicos e radiológicos de malformações em pequenos ruminantes no semiárido do estado da Bahia. Foram realizadas visitas técnicas em 41 propriedades rurais no município de Uauá, Bahia, e em cada uma delas foi aplicado um questionário epidemiológico. Adicionalmente, quando se observavam casos de malformações, os animais eram avaliados vivos ou mortos. Foram necropsiados oito animais (1, 2, 3, 4, 5, 6, 7 e 8), e dois (7 e 8) foram submetidos a exame radiográfico. Sobre a alimentação do rebanho, 40 (97,56%) produtores rurais relataram o livre acesso de seus animais à vegetação nativa. Em relação à presença de Mimosa tenuiflora, 5 (12,2%) informaram que os animais tinham acesso à planta, 15 (36,6 %) disseram que tinham pouco contato, enquanto que 21 (51,2 %) relataram que não havia nenhum contato com a planta, pois essa espécie não estava presente em número relevante na região. Vinte e cinco dos 41 proprietários (60,98%) relataram o consumo de Poincianella pyramidalis. Foi constatado ainda que na maioria das propriedades havia muitas áreas invadidas por P. pyramidalis (80-90% da vegetação). As principais anormalidades relatadas pelos entrevistados em 36 propriedades foram artrogripose (87,80%), agnatia [22 (53,66%)], desvio lateral da mandíbula [11 (26,82%)], escoliose [6 (14,63%)], micrognatia [6 (14,63%)], fenda palatina [4 (9,75%)], crânio aumentado de tamanho [4 (9,75%)], microftalmia [2 (4,88%)], braquignatismo [1 (2,43%)], exoftalmia [1 (2,43%)] e deformidades múltiplas no crânio [1 (2,43%)]. No exame clínico de 13 animais com malformações, as principais alterações foram artrogripose bilateral dos membros torácicos (6/13); queilosquise (2/13); micrognatia (1/13) e má oclusão dentária (1/13). Considerando que algumas dessas malformações foram reproduzidas experimentalmente em caprinos pode-se sugerir P. pyramidalis como mais uma planta teratogênica para ruminantes no Nordeste do Brasil.(AU)

The aim of this paper is to describe the epidemiological, clinical-pathological and radiological aspects of malformations in small ruminants in the semi-arid state of Bahia. Technical visits were carried out in 41 rural properties in the city of Uauá, Bahia, and in each of them, an epidemiological questionnaire was applied. In addition, when malformations were observed, the animals were evaluated alive or dead. Eight animals (1, 2, 3, 4, 5, 6, 7 and 8) were necropsied, and two (7 and 8) were submitted to radiographic examination. Regarding the feeding of the herd, 40 (97.56%) farmers reported the free access of their animals to the native vegetation. Regarding the presence of Mimosa tenuiflora, 5 (12.2%) said that the animals had access to the plant, 15 (36.6%) was informed they had little contact, while 21 (51.2%) reported that there was no contact with the plant, because this species were not present in a relevant number in the region. Twenty five out of 41 owners (60.98%) reported the consumption of Poincianella pyramidalis. It was also verified that in the majority of the properties there were many areas invaded by P. pyramidalis (80-90% of the vegetation). The main abnormalities reported by the interviewees on 36 properties were arthrogryposis (87.80%), agnatia [22 (53.66%)], lateral deviation of the mandible [11 (26.82%)], scoliosis [6 (14.63%)], micrognathia [6 (14.63%)], cleft palate [4 (9.75%)], skull enlarged in size [4 (9.75%)], microphthalmia [2 (4.88%)], braquignatism [1 (2.43%)], exophthalmia [1 (2.43%)] and, multiple deformities in the skull [1 (2.43%)]. In the clinical examination of 13 animals with malformations, the main alterations were bilateral arthrogryposis of the thoracic limbs (6/13); cleft lip (2/13); micrognathia (1/13) and dental malocclusion (1/13). Considering that some of these malformations were reproduced experimentally in goats, it is possible to suggest P. pyramidalis as another teratogenic plant for ruminants in Northeast Brazil.(AU)

Malformações em pequenos ruminantes no semiárido da Bahia: aspectos epidemiológicos, clínico-patológicos e radiológicos / Malformations in small ruminants in the semi-arid region of Bahia: epidemiological, clinical-pathological and radiological aspects

O objetivo do presente trabalho é descrever os principais aspectos epidemiológicos, clínico-patológicos e radiológicos de malformações em pequenos ruminantes no semiárido do estado da Bahia. Foram realizadas visitas técnicas em 41 propriedades rurais no município de Uauá, Bahia, e em cada uma delas foi aplicado um questionário epidemiológico. Adicionalmente, quando se observavam casos de malformações, os animais eram avaliados vivos ou mortos. Foram necropsiados oito animais (1, 2, 3, 4, 5, 6, 7 e 8), e dois (7 e 8) foram submetidos a exame radiográfico. Sobre a alimentação do rebanho, 40 (97,56%) produtores rurais relataram o livre acesso de seus animais à vegetação nativa. Em relação à presença de Mimosa tenuiflora, 5 (12,2%) informaram que os animais tinham acesso à planta, 15 (36,6 %) disseram que tinham pouco contato, enquanto que 21 (51,2 %) relataram que não havia nenhum contato com a planta, pois essa espécie não estava presente em número relevante na região. Vinte e cinco dos 41 proprietários (60,98%) relataram o consumo de Poincianella pyramidalis. Foi constatado ainda que na maioria das propriedades havia muitas áreas invadidas por P. pyramidalis (80-90% da vegetação). As principais anormalidades relatadas pelos entrevistados em 36 propriedades foram artrogripose (87,80%), agnatia [22 (53,66%)], desvio lateral da mandíbula [11 (26,82%)], escoliose [6 (14,63%)], micrognatia [6 (14,63%)], fenda palatina [4 (9,75%)], crânio aumentado de tamanho [4 (9,75%)], microftalmia [2 (4,88%)], braquignatismo [1 (2,43%)], exoftalmia [1 (2,43%)] e deformidades múltiplas no crânio [1 (2,43%)]. No exame clínico de 13 animais com malformações, as principais alterações foram artrogripose bilateral dos membros torácicos (6/13); queilosquise (2/13); micrognatia (1/13) e má oclusão dentária (1/13). Considerando que algumas dessas malformações foram reproduzidas experimentalmente em caprinos pode-se sugerir P. pyramidalis como mais uma planta teratogênica para ruminantes no Nordeste do Brasil.(AU)

The aim of this paper is to describe the epidemiological, clinical-pathological and radiological aspects of malformations in small ruminants in the semi-arid state of Bahia. Technical visits were carried out in 41 rural properties in the city of Uauá, Bahia, and in each of them, an epidemiological questionnaire was applied. In addition, when malformations were observed, the animals were evaluated alive or dead. Eight animals (1, 2, 3, 4, 5, 6, 7 and 8) were necropsied, and two (7 and 8) were submitted to radiographic examination. Regarding the feeding of the herd, 40 (97.56%) farmers reported the free access of their animals to the native vegetation. Regarding the presence of Mimosa tenuiflora, 5 (12.2%) said that the animals had access to the plant, 15 (36.6%) was informed they had little contact, while 21 (51.2%) reported that there was no contact with the plant, because this species were not present in a relevant number in the region. Twenty five out of 41 owners (60.98%) reported the consumption of Poincianella pyramidalis. It was also verified that in the majority of the properties there were many areas invaded by P. pyramidalis (80-90% of the vegetation). The main abnormalities reported by the interviewees on 36 properties were arthrogryposis (87.80%), agnatia [22 (53.66%)], lateral deviation of the mandible [11 (26.82%)], scoliosis [6 (14.63%)], micrognathia [6 (14.63%)], cleft palate [4 (9.75%)], skull enlarged in size [4 (9.75%)], microphthalmia [2 (4.88%)], braquignatism [1 (2.43%)], exophthalmia [1 (2.43%)] and, multiple deformities in the skull [1 (2.43%)]. In the clinical examination of 13 animals with malformations, the main alterations were bilateral arthrogryposis of the thoracic limbs (6/13); cleft lip (2/13); micrognathia (1/13) and dental malocclusion (1/13). Considering that some of these malformations were reproduced experimentally in goats, it is possible to suggest P. pyramidalis as another teratogenic plant for ruminants in Northeast Brazil.(AU)

Dental anomalies in Didelphis albiventris (Mammalia, Marsupialia, Didelphidae) from Argentina, Brazil and Uruguay

RESUMEN Las anomalías en la dentición se han estudiado en la mayoría de los órdenes de mamíferos, incluyendo marsupiales. Trabajos anteriores en Didelphis albiventris Lund, 1840 analizaron solamente un tipo de malformación, o un número acotado de ejemplares, subestimando así el tipo y número de anomalías para esta especie. El objetivo de este trabajo es describir y analizar varias anomalías dentales encontradas en muestras de Didelphis albiventris provenientes de Argentina, Uruguay y Brasil. Las anomalías se clasificaron en tres categorías: dientes supernumerarios o ausentes; anomalías morfológicas de tamaño y forma; y dientes en posiciones inusuales. De los 393 ejemplares analizados, encontramos 32 individuos de D. albiventris con anomalías (8,14%), algunos de los cuales presentaron más de una anomalía. Una proporción similar de especímenes de Argentina y Uruguay presentó anomalías, mientras que en la muestra de Brasil las anomalías fueron menos comunes. Las anomalías se encontraron más frecuentemente en la serie dentaria superior y en los molares, siendo los molares supernumerarios y los dientes con malformaciones en la corona las más comunes. El porcentaje de muestras con anomalías encontrado para D. albiventris es mayor que los reportados previamente para la especie y para otros Didelphimorphia. La endogamia y el flujo génico limitado no parecen ser posibles explicaciones para el elevado porcentaje de anomalías, especialmente debido a las características ecológicas de Didelphis albiventris. La inestabilidad en el desarrollo y la asimetría fluctuante podrían ser algunas de las causas de las anomalías, sobre todo debido a que el hábitat utilizado por D. albiventris tiende a ser inestable y encontrarse modificado. Las anomalías dentales se encontraran, principalmente, en las áreas de la serie dental donde la oclusión es relajado o no evita que los dientes ocluyan durante la masticación, y por lo tanto no tienen ningún valor funcional.

ABSTRACT Dental anomalies have been investigated and reported for most orders of mammals, including marsupials. Previous works in Didelphis albiventris Lund, 1840 only described one kind of malformation or just a few observations from some collections, thus the type and presence of anomalies for this species was underestimated. The aim of this contribution is to describe and analyze several dental anomalies found in specimens of Didelphis albiventris from Argentina, Uruguay and Brazil. Dental anomalies were classified in three categories: supernumerary or missing teeth, morphological anomalies in size and shape, and teeth in unusual positions. We found 32 individuals of D. albiventris with anomalies out of 393 analyzed specimens (8.14%), some specimens with more than one anomaly. A similar proportion of specimens from Argentina and Uruguay presented anomalies, while in specimens from Brazil anomalies were less common. Anomalies were more commonly found in the upper toothrow and in molars, being supernumerary teeth and molars with unusual crown-shape the most common ones. The percentage of specimens with anomalies found for D. albiventris is higher than previously reported for the species, and other Didelphimorphia. Inbreeding and limited gene flow do not appear as possible explanations for the elevated percentage of anomalies, especially due to the ecological characteristics of Didelphis albiventris. Developmental instability and fluctuating asymmetry could be some of the causes for the anomalies found in this species, mostly since the habitat used by D. albiventris tends to be unstable and disturbed. Dental anomalies were mostly found in areas of the toothrow where occlusion is relaxed or does not prevent teeth from interlocking during mastication, and consequently have no functional value.

Dental anomalies in Didelphis albiventris (Mammalia, Marsupialia, Didelphidae) from Argentina, Brazil and Uruguay / Anomalías en la dentición de Didelphis albiventris (Didelphidae)

Las anomalías en la dentición se han estudiado en la mayoría de los órdenes de mamíferos, incluyendo marsupiales. Trabajos anteriores en Didelphis albiventris Lund, 1840 analizaron solamente un tipo de malformación, o un número acotado de ejemplares, subestimando así el tipo y número de anomalías para esta especie. El objetivo de este trabajo es describir y analizar varias anomalías dentales encontradas en muestras de Didelphis albiventris provenientes de Argentina, Uruguay y Brasil. Las anomalías se clasificaron en tres categorías: dientes supernumerarios o ausentes; anomalías morfológicas de tamaño y forma; y dientes en posiciones inusuales. De los 393 ejemplares analizados, encontramos 32 individuos de D. albiventris con anomalías (8,14%), algunos de los cuales presentaron más de una anomalía. Una proporción similar de especímenes de Argentina y Uruguay presentó anomalías, mientras que en la muestra de Brasil las anomalías fueron menos comunes. Las anomalías se encontraron más frecuentemente en la serie dentaria superior y en los molares, siendo los molares supernumerarios y los dientes con malformaciones en la corona las más comunes. El porcentaje de muestras con anomalías encontrado para D. albiventris es mayor que los reportados previamente para la especie y para otros Didelphimorphia. La endogamia y el flujo génico limitado no parecen ser posibles explicaciones para el elevado porcentaje de anomalías, especialmente debido a las características ecológicas de Didelphis albiventris. La inestabilidad en el desarrollo y la asimetría fluctuante podrían ser algunas de las causas de las anomalías, sobre todo debido a que el hábitat utilizado por D. albiventris tiende a ser inestable y encontrarse modificado. Las anomalías dentales se encontraran, principalmente, en las áreas de la serie dental donde la oclusión es relajado o no evita que los dientes ocluyan durante la masticación, y por lo tanto no tienen ningún valor funcional.(AU)

Dental anomalies have been investigated and reported for most orders of mammals, including marsupials. Previous works in Didelphis albiventris Lund, 1840 only described one kind of malformation or just a few observations from some collections, thus the type and presence of anomalies for this species was underestimated. The aim of this contribution is to describe and analyze several dental anomalies found in specimens of Didelphis albiventris from Argentina, Uruguay and Brazil. Dental anomalies were classified in three categories: supernumerary or missing teeth, morphological anomalies in size and shape, and teeth in unusual positions. We found 32 individuals of D. albiventris with anomalies out of 393 analyzed specimens (8.14%), some specimens with more than one anomaly. A similar proportion of specimens from Argentina and Uruguay presented anomalies, while in specimens from Brazil anomalies were less common. Anomalies were more commonly found in the upper toothrow and in molars, being supernumerary teeth and molars with unusual crown-shape the most common ones. The percentage of specimens with anomalies found for D. albiventris is higher than previously reported for the species, and other Didelphimorphia. Inbreeding and limited gene flow do not appear as possible explanations for the elevated percentage of anomalies, especially due to the ecological characteristics of Didelphis albiventris. Developmental instability and fluctuating asymmetry could be some of the causes for the anomalies found in this species, mostly since the habitat used by D. albiventris tends to be unstable and disturbed. Dental anomalies were mostly found in areas of the toothrow where occlusion is relaxed or does not prevent teeth from interlocking during mastication, and consequently have no functional value.(AU)

Dental anomalies in Didelphis albiventris (Mammalia, Marsupialia, Didelphidae) from Argentina, Brazil and Uruguay / Anomalías en la dentición de Didelphis albiventris (Didelphidae)

Las anomalías en la dentición se han estudiado en la mayoría de los órdenes de mamíferos, incluyendo marsupiales. Trabajos anteriores en Didelphis albiventris Lund, 1840 analizaron solamente un tipo de malformación, o un número acotado de ejemplares, subestimando así el tipo y número de anomalías para esta especie. El objetivo de este trabajo es describir y analizar varias anomalías dentales encontradas en muestras de Didelphis albiventris provenientes de Argentina, Uruguay y Brasil. Las anomalías se clasificaron en tres categorías: dientes supernumerarios o ausentes; anomalías morfológicas de tamaño y forma; y dientes en posiciones inusuales. De los 393 ejemplares analizados, encontramos 32 individuos de D. albiventris con anomalías (8,14%), algunos de los cuales presentaron más de una anomalía. Una proporción similar de especímenes de Argentina y Uruguay presentó anomalías, mientras que en la muestra de Brasil las anomalías fueron menos comunes. Las anomalías se encontraron más frecuentemente en la serie dentaria superior y en los molares, siendo los molares supernumerarios y los dientes con malformaciones en la corona las más comunes. El porcentaje de muestras con anomalías encontrado para D. albiventris es mayor que los reportados previamente para la especie y para otros Didelphimorphia. La endogamia y el flujo génico limitado no parecen ser posibles explicaciones para el elevado porcentaje de anomalías, especialmente debido a las características ecológicas de Didelphis albiventris. La inestabilidad en el desarrollo y la asimetría fluctuante podrían ser algunas de las causas de las anomalías, sobre todo debido a que el hábitat utilizado por D. albiventris tiende a ser inestable y encontrarse modificado. Las anomalías dentales se encontraran, principalmente, en las áreas de la serie dental donde la oclusión es relajado o no evita que los dientes ocluyan durante la masticación, y por lo tanto no tienen ningún valor funcional.

Dental anomalies have been investigated and reported for most orders of mammals, including marsupials. Previous works in Didelphis albiventris Lund, 1840 only described one kind of malformation or just a few observations from some collections, thus the type and presence of anomalies for this species was underestimated. The aim of this contribution is to describe and analyze several dental anomalies found in specimens of Didelphis albiventris from Argentina, Uruguay and Brazil. Dental anomalies were classified in three categories: supernumerary or missing teeth, morphological anomalies in size and shape, and teeth in unusual positions. We found 32 individuals of D. albiventris with anomalies out of 393 analyzed specimens (8.14%), some specimens with more than one anomaly. A similar proportion of specimens from Argentina and Uruguay presented anomalies, while in specimens from Brazil anomalies were less common. Anomalies were more commonly found in the upper toothrow and in molars, being supernumerary teeth and molars with unusual crown-shape the most common ones. The percentage of specimens with anomalies found for D. albiventris is higher than previously reported for the species, and other Didelphimorphia. Inbreeding and limited gene flow do not appear as possible explanations for the elevated percentage of anomalies, especially due to the ecological characteristics of Didelphis albiventris. Developmental instability and fluctuating asymmetry could be some of the causes for the anomalies found in this species, mostly since the habitat used by D. albiventris tends to be unstable and disturbed. Dental anomalies were mostly found in areas of the toothrow where occlusion is relaxed or does not prevent teeth from interlocking during mastication, and consequently have no functional value.

Incidência do primeiro molar em cavalos Crioulos e sua correlação com a genética

A valorização de animais com alto desempenho funcional e alto valor zootécnico, fez com que a criação desses animais fosse conduzida em alta escala, concentrando muitas vezes uma mesma linhagem, a fim de acelerar o melhoramento e valorizar seus produtos. Com isso, a consanguinidade é uma realidade dentro das criações. Além disso, deu-se a modificação dos hábitos alimentares naturais do cavalo, alterando substancialmente o padrão de mastigação. Com isso, as mais variadas alterações odontológicas passaram a ter influência no desenvolvimento e performance. A odontologia equina não está incluída nos critérios de seleção de animais para a reprodução, principalmente devido a ausência de estudos correlacionando anormalidades odontológicas com a genealogia e desempenho. Entretanto, isto é muito importante, pois orientará o criador para evitar efeitos indesejáveis da endogamia. Entre as anormalidades odontológicas o dente de lobo ou pré-molar 1 (PM1) é a mais frequente. Com base nisto, este estudo teve o objetivo de avaliar a incidência do PM1 e identificar os fatores que contribuem para sua variação em uma amostra de 443 equinos, machos e fêmeas da raça Crioula examinados clinicamente, entre os anos de 2013 e 2014. Um total de 223 (50,34%) de animais apresentaram o primeiro pré-molar. Avaliações usando qui-duadrado (2) não identificaram nenhuma associação significativa (P=0,4648) entre sexo e a presença do primeiro pré-molar. As percentagens de ocorrência de acordo com a posição 105, 205 e ambas (105-205) foram respectivamente, 6,32%, 7,00% e 37,02%. Houve uma associação significativa (P < 0,0001) entre a idade do animal (grupos de I, II e III) e a presença de dente de lobo. A maior frequência de dente de lobo foi observada em animais do grupo I (idade de 1 a 3 anos) e a menor em animais do grupo III (acima de 10 anos). Houve uma associação também significativa entre linhagens (brasileira, uruguaia e chilena) e a presença de dente de lobo. A maior incidência de dente de lobo ocorreu na linhagem uruguaia (66,67%) e a menor na linhagem brasileira (46,35%). A consanguinidade avaliada na população analisada variou entre 0,0 e 0,2812. A consanguinidade média (erro padrão) em machos foi de 0,015 (0,026) e em fêmeas 0,009 (0,021). As consanguinidades entre 9 animais sem e com dente de lobo foram: 0,011 (0,025) e 0,015 (0,024) respectivamente. As consanguinidade média e erros padrão de acordo com os grupos de idade (I, II e III) foram: 0,016 (0,021), 0,014 (0,027) e 0,007 (0,019) respectivamente. As médias de consanguinidade e desvio padrão de acordo com as linhagens (brasileira, chilena e uruguaia) foram: 0,009 (0,019), 0,011 (0,012) e 0,023 (0,032) respectivamente.Dos 443 animais coletados foram escolhidos 50 para análise do gene MSX1, sendo 25 com presença de dente de lobo e 25 sem esta alteração. Estas 50 amostras foram submetidas a análise de SSCP e sequenciamento para verificação de polimorfismo no primeiro exon do gene MSX1. Embora nenhuma relação de causa tenha sido estabelecida entre o exon I do gene MSX1 e a presença de dente de lobo, esta é a primeira tentativa de relacionar este tipo de alteração dentária e gene homeobox em equinos. Podemos concluir neste estudo que há uma forte relação entre dente de lobo com idade e linhagem, mas não há influência do sexo sobre esta alteração dentária. Uma grande influência genética também existe, pois há uma expressão mais forte (ocorrência) desta anomalia na arcada dentária superior. De forma especulativa podemos dizer que estas associações observadas neste trabalho sejam em parte devido aos níveis de consanguinidades apresentados pelos animais avaliados.

The placement values in high functional performance animals and high value livestock, made the breeding of these individuals wascarried out in high scale, focusing often the same lineages in order to accelerate the improvement and enhance their products. So, inbreeding is a reality within the creations. In addition, there was the modification of natural horse eating habits, substantially altering the pattern of chewing. With this, the most varied dental disorders started to have an influence in the performance. Equine dentistry is not included in the selection criteria of animals for reproduction, mainly due to lack of studies correlating dental abnormalities with genealogy and athletic performance. However, this is very important, as it will guide the breeder to avoid undesirable effects of inbreeding. Among the dental abnormalities wolf tooth or premolar 1 (PM1) is the most frequent. On this basis, this study aimed to assess the impact of PM1 and identify the factors contributing to the variation in a sample of 443 horses, male and female of the Criollo breed examined clinically, between the years 2013 and 2014. Two hundred and twenty three out of 443 animals, (approximately 50.34%), showed the first premolar. Assessments using chi-square (2) did not identify any significant association (P = 0.4648) between sex and the presence of the first premolar. The percentages of occurrence in accordance with the position 105, 205 and both (105-205) were, respectively 6.32%, 7.00% and 37.02%. There was a significant association (P <0.0001) between the age of the animal (groups 1-3) and the presence of wolf tooth. The highest frequency of wolf tooth wasobserved in animals from group I (age 1-3 years) and the lowest in animals of group III (above 10 years). There was also a significant association (P=0.0004) between lineages (Brazilian, Uruguayan and Chilean) and the presence of wolf tooth. The highest incidence of wolf tooth occurred in the Uruguayan lineage (66.67%) and the lowest in the Brazilian strain (46.35%). Inbreeding evaluated in the study population ranged from 0.0 to 0.2812. The average inbreeding (standard error) in males was 0.015 (0.026) and females 0.009 (0.021). The inbreeding among animals with and without wolf tooth were 0.011 (0.025) and 0.015 (0.024) respectively. The mean and standard errors from inbreeding 11 coefficientin accordance with age groups (I, II and III) were 0.016 (0.021) 0.014 (0.027) and 0.007 (0.019), respectively. The mean and standard deviation of consanguinity according to the lineages (Brazilian, Chilean and Uruguayan) were 0.009 (0.019) 0.011 (0.012) and 0.023 (0.032), respectively. Fifty out of 443 animals were selected for genetic analysis, 25 with the presence of wolf tooth and 25 without this change. Genomic DNA was extracted from whole blood and checked on 1% agarose gel. These 50 samples were subjected to SSCP analysis and sequencing to check polymorphism in the first exon of the gene MSX1. Although no causal relationship has been established between exon I of MSX1 gene and the presence of wolf tooth, this is the first attempt to relate this kind of change and homeobox gene in horses. We can conclude from this study that there is a strong relationship between wolf tooth with age and lineage, but there is no influence of gender on this dental anomaly. A large genetic influence also exists because there is a stronger expression (occurrence) of this anomaly in the upper dental arch. Speculatively,we can say that these associations observed in this study are partly due to inbrreding levels presented by the evaluated animals.