Probiótico em dieta de alto grão com núcleo proteico extrusado para bovinos de corte

Abstract

The objective of this work was to test the efficiency of the commercial probiotic (BacSol®) 5 x 106 CFU / g Saccharomyces cerevisiae and 2.0 x 107 CFU / g Bacillus subtili in the ruminal pH control at 0 g (control), 1.5 g; 3.0 g; 6.0 g and 9.0 g, with high grain diet. The additive was tested in five Nelore females, with a mean live weight of 408 kg, fistulated in the rumen, with a basal diet composed of 80% whole grain corn and 20% extruded protein core. The animals were de-wormed, underwent the adaptation period of 21 days and received two daily treatments at 8:00 a.m. and 4:00 p.m., with adjustment of the diet every 2 days to keep the remains close to 5% of the supply and consumption of dry matter of 2.2% of the live weight of the final diet. The daily dosages of the probiotic additive (BacSol®) were divided into two equal portions and placed directly in the rumen at 08:00 and 16:00. For pH evaluation, the ruminal juice was collected on the seventh day of each experimental period at 08:00, 10:00, 12:00, 14:00, 16:00, 18:00 and 20:00 hours, , 0, 2, 4, 6, 8, 10 and 12 hours after the first daily treatment of the animals. During the experimental period, animal faeces were scored using visual scores from 1 to 5, as indicative of probable digestive disturbances and alteration of ruminal pH. The data were analyzed using the GLM procedure of the statistical package SAS (1999), where the Friedman test of independent samples was used for the means of non-parametric variables (P <0.05). The probiotic was not effective in controlling ruminal pH near the physiological level in any of the doses of 1.5; 3.0; 6.0 and 9.0 g, the average pH being 5.62. The additive also had no significant effect on the 4 dosages tested during ruminal fluid sampling at 0, 2, 4, 6, 8, 10, and 12 hours after the first feed. There was no significant difference between the five treatments when compared to faecal scores. Therefore, the microbial additive was not effective in controlling the ruminal pH of cattle fed a high grain diet in the proportion of 80:20 maize and protein core, respectively. Key words: acidosis, confinement, ruminal pH.