Análise multivariada na morfometria do casco de bovinos Nelore confinados e criados na pastagem / Multivariate analysis in hoof morphometry in Nellore cattle in feedlot and grazing breeding systems

RESUMO

O manejo intensivo favorece a ocorrência de afecções podais inflamatórias ou infecciosas nos animais de produção. O objetivo do presente trabalho foi determinar o impacto do tipo de piso sobre o casco ao analisar a morfometria externa dos dígitos de bovinos Nelore confinados e em pastagem e, ainda, verificar a eficácia da análise exploratória multivariada para esse conjunto de dados. Foram avaliados vinte quatro animais sendo doze mantidos em confinamento e o restante no pasto. O abate dos ruminantes foi realizado aos 20 meses de idade. Seccionadas na articulação carpometacárpica e tarsometatársica, as extremidades dos membros torácicos e pélvicos dos 24 animais foram amostradas e congeladas à -20ºC. Posteriormente mensuradas com fita métrica milimetrada no dígito lateral e medial para obtenção da altura da parede abaxial e axial, comprimento e largura da sola, comprimento, largura e altura do bulbo e o comprimento da parede lateral da úngula. A análise exploratória multivariada de correspondência múltipla mostrou associação entre tais medidas em amostras oriundas dos indivíduos no confinamento e no pasto. Animais confinados apresentaram paredes axial e abaxial mais altas, altura do bulbo maior e sola menor. Quando mantidos no solo da pastagem, os dígitos tiveram bulbo mais baixo e maior comprimento de sola. Embora haja variação individual na morfometria do casco, o ambiente...(AU)

ABSTRACT

Intensive management favors the occurrence of inflammatory or infectious foot diseases in farm animals. The objective of the present study was to determine the impact on the hooves caused by the type of floor and also to verify the effectiveness of the multivariate exploratory analysis for this data set. For that, the analysis of digits external morphometry of Nellore cattle confined and on grazing was carried out. Twenty-four animals were evaluated, twelve of which were kept in confinement and the rest in pasture. Ruminants were slaughtered at 20 months of age. Sectioned in the carpometacarpal and tarsometatarsal joints, the extremities of the thoracic and pelvic limbs of the 24 animals were sampled and frozen at -20ºC. Subsequently measured with a millimeter metric tape on the lateral and medial region of the digits to obtain the height of the abaxial and axial wall, length and width of the sole, length, width and height of the bulb and the length of the lateral wall ofthe hoof. The multivariate exploratory analysis of multiple correspondence showed an association between such measures insamples from individuals in confinement and pasture. Confined animals had higher axial and abaxial walls, higher bulb height and smaller sole. When kept in the pasture soil, the digits had a lower bulb and a longer sole length. Although there is individual variation in the hull morphometry, the environment alone can change its structure. Higher hoof wall in confined cattle suggests less wear on the keratinized portion, while the greater development of the sole in animals raised on pasture maybe related to better distribution of forces on the support surface. Thus, it is observed that the environment modifies its anatomical structure. The multiple correspondence analysis is efficient in identifying dependencies between categories of external morphometric parameters of bovine hooves.(AU)