ABSTRACT
A bacterial strain of Clostridium sordellii and another one of Peptostreptococcus tetradius (isolated in a previous study, from the cecum of fattening rabbits) were evaluated as supplements, administered by means of food aspersion on a commercial feed for weaned fattening white New Zealand rabbits. The study was carried out in a rabbit fattening farm with 60% morbidity and 50% mortality due to unspecific diarrheas. Three experimental groups were formed: the first group was fed normal commercial feed, the second commercial feed inoculated with C. sordellii and the third, inoculated with P. tetradius. Daily weight gain, feed consumption and feed efficacy were evaluated during five weeks, and three tests of apparent digestibility were made. In addition, the mortality and the morbidity caused by unspecific diarrheas during the same period were quantified. After the rabbits were euthanized, total and cellulolytic bacteria concentration, pH and ammonium concentration were measured from samples taken from the cecal appendix, thirteenth cecal loop and colon. The results did not show significant difference (P > 0.05) between the treatments for any of the production variables measured. Statistical differences (P < 0.05) were found in pH and ammonium concentration in the cecal appendix between the group with C. sordellii and the other two groups, while in the thirteenth cecal loop differences were found (P < 0.05) in ammonium concentration between the group with P. tetradius and the other two groups. In regard to total bacteria, differences (P < 0.05) were found at the cecal appendix level between the control group and the one that received P. tetradius, and at the colon level between the group that received P. tetradius and the one that received C. sordelli. C. sordellii supplementation was associated with lower diarrheal morbidity (35%), as compared with that observed in the control group (80%), and that of the group receiving the P. tetradius supplement (80%) (P < 0.05).
Se evaluó una cepa bacteriana de Clostridium sordellii y otra de Peptostreptococcus tetradius (aisladas en un trabajo previo, a partir del ciego de conejos en engorda) como complementos, suministrados mediante aspersión en alimento comercial para conejos Nueva Zelanda, blancos, recién destetados y en etapa de engorda. El trabajo se llevó a cabo en un centro de engorda cunícola en el cual se presentaba morbilidad de 60% y mortalidad de 50% a causa de diarreas inespecíficas. Se crearon tres grupos experimentales: al primero se le proporcionó alimento comercial sin inocular, al segundo se le proporcionó alimento comercial adicionado con C. sordellii y al tercero, adicionado con P. tetradius. Se evaluó ganancia diaria de peso, consumo de alimento y eficiencia alimenticia durante cinco semanas, además se realizaron tres ensayos de digestibilidad aparente. Asimismo, se cuantificó la mortalidad y la morbilidad causada por diarreas inespecíficas durante el periodo señalado. Después del sacrificio de los conejos, se midió la concentración de bacterias totales y celulolíticas, pH y amonio en muestras del apéndice cecal, treceava asa cecal y colon. Los resultados no mostraron diferencia significativa (P > 0.05) entre los tratamientos para ninguna de las variables productivas medidas. Se encontraron diferencias estadísticas (P < 0.05) en el pH y la concentración de amonio a nivel del apéndice cecal entre el grupo al que se le suministró C. sordelliiy los dos grupos restantes, mientras que a nivel de la treceava asa cecal se encontraron diferencias (P < 0.05) en la concentración de amonio entre el grupo que recibió P. tetradius y los otros dos grupos. En lo referente a bacterias totales se encontraron diferencias (P < 0.05) a nivel de apéndice cecal entre el grupo testigo y el que recibió P. tetradius, y a nivel de colón distal entre el grupo que recibió C. sordellii y P. tetradius. La administración de C. sordelli estuvo asociada a una morbilidad diarreica más baja (35%) que la observada en el caso del grupo testigo (80%) y del grupo que recibió complemento de P. tetradius (80%) (P < 0.05).