Effects of corn silage inclusion in preweaning calf diets.

The objective of this research was to evaluate the effects of corn silage inclusion in starter feed provided to calves after birth through weaning at 7 wk of age. Thirty-six heifer calves and 9 bull calves were individually housed in hutches. Calves in treatment groups received pasteurized milk with all calf starter, 25% calf starter and 75% corn silage, or all corn silage. Values were recorded daily for feed intake and health, which included fecal, respiratory, and attitude scores; and at wk 2, 4, and 8 for concentrations of serum protein, hematocrit, and serum ß-hydroxybutyrate. Body weight, withers height, and hip height were measured at wk 2, 4, 8, and 52. Nine bull calves (3/treatment) were killed at 8 wk of age for assessment of rumen and intestinal tissue morphology. Feed intake and average daily gain were not different among treatments. Least squares means of rumen papillae lengths were significantly different and decreased as corn silage inclusion increased. Crypt depths and total thickness of epithelium were reduced for the corn silage group. Least squares means of body weight, heart girth, hip height, withers height, serum protein, hematocrit, and ß-hydroxybutyrate concentrations did not differ among treatments. These data indicated that the mixture of corn silage and starter did not affect growth, feed intake, or intestinal morphology but did affect rumen wall morphology. Feeding solely corn silage as starter feed stunted the growth of rumen papillae and tended to impair intestinal morphology, indicating that only calf starter or a mixture of calf starter and corn silage is more appropriate.

Oral probiotic combination of Lactobacillus and Bifidobacterium alters the gastrointestinal microbiota during antibiotic treatment for Clostridium difficile infection.

Perturbations in the gastrointestinal microbiome caused by antibiotics are a major risk factor for Clostridium difficile infection (CDI). Probiotics are often recommended to mitigate CDI symptoms; however, there exists only limited evidence showing probiotic efficacy for CDI. Here, we examined changes to the GI microbiota in a study population where probiotic treatment was associated with significantly reduced duration of CDI diarrhea. Subjects being treated with standard of care antibiotics for a primary episode of CDI were randomized to probiotic treatment or placebo for 4 weeks. Probiotic treatment consisted of a daily multi-strain capsule (Lactobacillus acidophilus NCFM, ATCC 700396; Lactobacillus paracasei Lpc-37, ATCC SD5275; Bifidobacterium lactis Bi-07, ATCC SC5220; Bifidobacterium lactis B1-04, ATCC SD5219) containing 1.7 x 1010 CFUs. Stool was collected and analyzed using 16S rRNA sequencing. Microbiome analysis revealed apparent taxonomic differences between treatments and timepoints. Subjects administered probiotics had reduced Verrucomicrobiaceae at week 8 compared to controls. Bacteroides were significantly reduced between weeks 0 to 4 in probiotic treated subjects. Ruminococcus (family Lachnospiraceae), tended to be more abundant at week 8 than week 4 within the placebo group and at week 8 than week 0 within the probiotic group. Similar to these results, previous studies have associated these taxa with probiotic use and with mitigation of CDI symptoms. Compositional prediction of microbial community function revealed that subjects in the placebo group had microbiomes enriched with the iron complex transport system, while probiotic treated subjects had microbiomes enriched with the antibiotic transport system. Results indicate that probiotic use may impact the microbiome function in the face of a CDI; yet, more sensitive methods with higher resolution are warranted to better elucidate the roles associated with these changes. Continuing studies are needed to better understand probiotic effects on microbiome structure and function and the resulting impacts on CDI.