Characterization of Shiga toxin - producing Escherichia coli infections in beef feeder calves and the effectiveness of a prebiotic in alleviating Shiga toxin - producing Escherichia coli infections

Evaluation of long-term supplementation of a Bacillus subtilis direct-fed microbial and enzymatically hydrolyzed yeast cell culture product used alone or in combination on Clostridia, Clostridium perfringens, Escherichia coli, and Salmonella prevalence in beef steers

The objective was to determine the influence of long-term supplementation (258 d) of a direct-fed microbial (DFM) and/or yeast cell wall (YCW) product on bacterial populations in beef steers. Single-sourced Charolais × Red Angus steers (n = 256; body weight = 246 ± 1.68 kg) were used in a randomized complete block design and blocked by location into one of four treatments: 1) fed no DFM and no YCW (Control); 2) fed only the DFM (DFM; Certillus CP B1801 Dry, 28 g/steer d-1 ); 3) fed only the YCW (YCW; Celmanax; 18 g/steer d-1 ); and 4) fed the DFM and the YCW (DFM+YCW). Steers were vaccinated for respiratory and clostridial diseases and treated for internal and external parasites at processing and individually weighed on days 1, 14, 42, 77, 105, 133, 161, 182, 230, and 258. To determine bacterial prevalence, fecal samples were collected on days 1, 14, 77, 133, 182, and 230 and environmental (pen area, feed, and water) samples were collected at the beginning of the week when cattle were weighed. No treatment × day interactions or treatment effects (P > 0.05) were observed between treatment groups at any sampling days for the bacterial populations. Samples on days 1, 133, and 182 had greater (P < 0.05) Clostridia levels compared to the other sampling points but were not different from each other. Clostridia levels were also greater (P < 0.05) on day 77 compared to days 14 and 230. Samples on days 77 and 230 had greater (P < 0.05) Clostridium perfringens levels compared to the other sampling points but were not different (P > 0.05) from each other. Samples on days 1 and 14 had lower (P < 0.05) total Escherichia coli levels compared to the other sampling points but were not different (P > 0.05) from each other. Escherichia coli levels on day 77 were higher (P < 0.05) compared to days 133, 182, and 230. Little Salmonella prevalence (1.5%) was observed throughout the study. This study had greater levels of Clostridia compared to small and large commercial feedlots in the Church and Dwight research database, but C. perfringens, total and pathogenic E. coli, and Salmonella prevalence were notably lower. Collectively, there were no appreciable treatment influences on bacterial populations. These data further indicate a low pathogenic bacterial challenge at the trial site, which could partially explain the lack of differences with DFM or YCW supplementation. The DFM and YCW used alone or in combination cannot be expected to show additional benefits when animals are relatively unstressed with a low pathogenic bacterial challenge.

Effect of enzymatically hydrolyzed yeast on health and performance of transition dairy cattle

The objective of this study was to evaluate the effect of supplementing enzymatically hydrolyzed yeast (EHY; Celmanax Arm and Hammer Animal Nutrition, Princeton, NJ) on transition dairy cattle. Forty multiparous Holstein cows were blocked by predicted transmitting ability and randomly assigned to 1 of 2 treatments (EHY, n = 20; or control, CON, n = 20) from 21 d before expected calving to 60 d postpartum. The EHY cows received 56 and 28 g/d in close-up and lactating diets, respectively. Dry matter intake, health events, milk production parameters, feed efficiency, colostrum quality, reproductive parameters, body weight, and body condition score were monitored. Fecal samples collected on -21, -14, -7, 0, 1, 3, 5, 7, and 14 d relative to calving were analyzed for total coliforms, Clostridium perfringens, Salmonella, and Escherichia coli O157:H7. Blood samples were collected at 7, 14, and 21 d postpartum for analysis of β-hydroxybutyrate. Sterile quarter milk samples collected at dry-off, calving, and wk 1, 2, and 3 of lactation were analyzed for milk pathogens and somatic cell count. Pre- or postpartum dry matter intake, body weight, body condition score, milk yield, and milk protein and fat yields did not differ among treatments. Milk fat and protein concentrations were greater in EHY cows than CON cows. β-Hydroxybutyrate and health events were not different among treatments. The presence of fecal C. perfringens did not differ prepartum, but was lower in EHY cows postpartum. Milk pathogens and total intramammary infections did not differ between treatments at dry-off, calving, wk 1, or wk 2, but more EHY cows were infected with Staphylococcus sp. during wk 3 than CON cows. The EHY cows showed heat earlier than CON cows, but no other reproductive parameters were affected. The EHY supplementation during the transition period did not affect dry matter intake, milk yield, health events, or reproductive parameters but did increase milk protein and fat concentrations.

Expert consensus document: The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on the definition and scope of prebiotics

In December 2016, a panel of experts in microbiology, nutrition and clinical research was convened by the International Scientific Association for Probiotics and Prebiotics to review the definition and scope of prebiotics. Consistent with the original embodiment of prebiotics, but aware of the latest scientific and clinical developments, the panel updated the definition of a prebiotic: a substrate that is selectively utilized by host microorganisms conferring a health benefit. This definition expands the concept of prebiotics to possibly include non-carbohydrate substances, applications to body sites other than the gastrointestinal tract, and diverse categories other than food. The requirement for selective microbiota-mediated mechanisms was retained. Beneficial health effects must be documented for a substance to be considered a prebiotic. The consensus definition applies also to prebiotics for use by animals, in which microbiota-focused strategies to maintain health and prevent disease is as relevant as for humans. Ultimately, the goal of this Consensus Statement is to engender appropriate use of the term 'prebiotic' by relevant stakeholders so that consistency and clarity can be achieved in research reports, product marketing and regulatory oversight of the category. To this end, we have reviewed several aspects of prebiotic science including its development, health benefits and legislation.