Parámetros protéicos del plasma seminal y su relación con la calidad del semen en toros de la raza nelore (bos taurus indicus)

The purpose of this study was to investigate the presence and incidence of specific protein bands onthe Nelore bulls' seminal plasma, fit for reproductive activity complete or partially. There were used 68 samples; 20 of the Census and 48 of the Blunt variety, with an average age of 4 years. In the scrotum perimeter (35,05 ± 0,49 cm and 33,30 ± 0,39 cm),corporal mass index (302,62 ± 5,87 and 284,19 ±5,15 Kg|m2) there was difference (p 0,05). In spermatic morphology, neither was there inequality between Census and Blunt varieties, with 5,06 ± 8,20% and 5,32 ± 6,40% of mayor defects respectively; 9,91 ± 6,74% and 8,36 ±6,06% for the minor defects; and 14,76 ± 13,20% and 13,82 ± 12,61% for total defects. The electro phoresis of the seminal plasma revealed protein bands with weights between 5 and 105 KDa. In 100% of bulls fit for reproduction, there was found protein with a weight of 13 Kda, as well as bands of 20 KDa.The other protein bands showed their presence with different incidence percentages in bulls totally orpartially fit for reproductive activity. Both of the studied varieties made evident the effective reproductive adaptation under similar climate conditions.