Rumenocentesis dorsomedial: Un procedimiento seguro para la obtención de líquido ruminal en vacas lecheras a pastoreo

Abstract

Two experiments were carried out to 1) compare pH values of rumen fluid samples (RF) obtained from dairy cows by dorsomedial rumenocentesis, a probe and permanent cannula and 2) to evaluate the effectiveness of the rumenocentesis and its effects on the health and performance of Holstein- Frisian grazing dairy cows. Experiment 1: Four lactating grazing Holstein-Frisian cows with a permanent rumen cannula were used. RF samples were obtained at 8:30, 13:30 and 17:30 hours, using a probe and the cannula (from caudoventral, caudodorsal, ventral and dorsal sacs). A RF sample was also obtained at 17:30 hours by dorsomedial rumenocentesis. pH of the samples obtained by rumenocentesis and from the caudoventral sac were similar and correlated (r = 0.77). Experiment 2: A dorsomedial rumenocentesis was performed in 30 grazing lactating Holstein-Frisian cows. The procedure was repeated every 5 days during one month and its effectiveness and effect on the health and performance of the cows were evaluated. The rumenocentesis was effective to obtain RF samples for pH determination (> 3mL) in all cases (n = 150). Reactions movements to the procedure were within accepted limits and more intensive at the first attempts. The performance and rectal temperature of the cows were not affected. A temporary swelling (1.0-1.5 cm) on the area was appreciated in 4% of the cases. It is concluded that dorsomedial rumenocentesis is a practical and safe procedure to obtain RF samples in grazing dairy cows under field conditions to evaluate the acid base balance of the rumen. © 2013 Facultad de Ciencias Veterinarias.