Ultrassonografia testicular na avaliação andrológica de touros da raça nelore e composto montana tropical

• Autor(a) principal: Pinho, Rogério Oliveira
• Data de Publicação: 2010
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1441
• topic: Ecotextura testicular; Qualidade seminal; Touros; Ultrassonografia; Testicular echotexture; Sperm quality; Bulls; Ultrasonography; CNPQ::CIENCIAS AGRARIAS::MEDICINA VETERINARIA::REPRODUCAO ANIMAL

The objective was to study the pattern of testicular echogenicity in young bulls at different sexual maturity stages and the relationship between testicular echotexture and degree of commitment caused by fibrotic lesions with semen quality of adult Nelore and Montana Tropical Compound bulls. There were used 405 young (aged between 21 and 33 months) and 402 adult Nelore bulls (2.8 to 11.1 years of age), 52 young (22 to 33 months of age) and 109 adult Montana Tropical Compound bulls (2.9 to 11.8 years of age). The animals were evaluated for breeding soundness examination and classified as sound and unsound for breeding by physical and morphological semen aspects. All animals underwent ultrasound examination of the testes, forming images in longitudinal planes on the caudal face of left and right testis and the images were transferred to computer with the software "Image J", capturing the average pixel intensity of each testicular region image, on a scale of pixel values ranging from 0 (anechoic, black image) to 255 (hyperechoic, white image). Additionally, a testicular fibrosis points score, ranged from 0 to 6 was assigned, to quantify the patterns, size and frequency of fibrotic lesions, where: 0) no fibrosis points observed in the testicular parenchyma; 1) 1 to 10 fibrosis points around the testicular parenchyma; 2) 11 to 30 fibrosis points around the testicular parenchyma; 3) 31 to 50 fibrosis points around the testicular parenchyma; 4) 51 to 100 fibrosis points around the testicular parenchyma; 5) over than 100 fibrosis points around the testicular parenchyma; 6) fibrosis areas in various shapes accompanied by fibrosis points. The frequency of young animals sound for breeding was 68.7 and 30.8% for Nelore and Montana Tropical Compound bulls, respectively, while for adult bulls higher averages were observed with 91.3 and 87.2% for Nelore and Montana Tropical Compound bulls, respectively. Regarding pixel intensity, the testicular parenchyma of evaluated bulls has shown a homogeneous and moderately echogenic pattern, with pixel intensity of young bulls ranging from 102.0 to 105.1 for Nelore bulls and 94.0 to 95.7 for Montana Tropical Compound bulls. In adult animals the range was 89.9 to 95.8 in Nelore bulls and 92.4 to 95.3 in Montana Tropical Compound bulls. There was no correlation between studied characteristics and pixel intensity values of the studied images (p > 0.05). Regarding adult bulls the testicular fibrosis points scores showed low correlation with scrotal circumference, testicular volume and medium correlation with animals age of both breeds (p < 0.05) having no correlation of fibrosis points scores with testicular sperm quality (p > 0.05). Therefore, only the testicular ultrasound used for young animals at the age of the present study does not allow evaluation of the level of sexual maturity of themselve. Quantification of pixel intensity through testis ultrasound evaluation was not effective in determining the reproductive capability of adult bulls. Moreover, the varying degrees of testicular fibrosis did not affect sperm quality.