ENDOSCOPIC TECHNIQUE TO FOLLOW THE MIXING AND BREAKDOWN OF COLORED FORAGE PARTICLES IN THE RUMINO-RETICULUM OF CATTLE

Three steers prepared with rumen fistulae were used in a completely randomized design to investigate the possibility of using an endoscopic technique to study particulate movement in the rumino-reticulum. Two particle sizes, small particles (1–2 mm, SP) and large particles (10 mm, LP), were introduced into three different locations in the rumino-reticulum at different times. Their movements were inferred from measurements of their presence in seven different areas of the rumino-reticulum by means of a modified endoscope. The breakdown of LP was also calculated. The overall half life (T 1/2) and turnover time for SP were 5.24 ± 0.77 h and 7.56 ± 1.11 h, respectively. Following addition to the rumen both LP and SP mixed throughout the contents. LP disappearance yielded a linear regression equation when values were expressed on a natural log basis. The equations of the kinetic curves of total, intermediate and small fractions were quadratic. In all cases, the equations had an R 2  = 0.88 or greater (P < 0.03). The general movement of particulate matter was circular, starting from the anterior and moving posterior via the ventral contents and then moving in reverse through the dorsal area. It was concluded that this endoscopic technique will contribute to the study of rate of passage of digesta and distribution pattern of the rumino-reticulum particulate matter, as well as its breakdown. Key words: Endoscopy, particle movement, rumino-reticulum, cattle