SB-020

This study evaluated the effects of Sweet Bran (SB) and wet distillers grains with solubles (WDGS) in the diet alone or in combination on physically effective neutral detergent fiber (peNDF), ruminal pH, and rumination behavior of finishing beef cattle. For this study, 455 steers (373 ± 15.5 kg) were allocated to 48 pens in a randomized complete block design. Treatments (n = 12 pens per treatment) were one of four steam-flaked corn-based diets containing no corn-milling products (CON), 20% WDGS (WDGS20), 20% SB (SB20), or 20% SB and 10% WDGS (COMBO). Within each pen, two steers were randomly selected to receive an indwelling ruminal pH bolus to quantify ruminal pH and a 3-axis accelerometer tag to measure rumination for the first 92 d of the study. Diet samples were collected weekly to determine particle size, neutral detergent fiber (NDF) concentration, and peNDF. Physically effective NDF was calculated using both the proportion of particles > 4.0 mm (peNDF4.0) and the proportion of particles > 8.0 mm (peNDF8.0). The percentage of particles > 4.0 mm was greatest (P < 0.01) for CON, intermediate for SB20, and least for WDGS20 and COMBO. Both NDF (P < 0.01) and peNDF4.0 (P < 0.01) were greatest for COMBO, intermediate for WDGS20 and SB20, and least for CON. The percentage of particles > 8.0 was greatest (P < 0.01) for CON, intermediate for WDGS20 and SB20, and least for COMBO, but peNDF8.0 did not differ (P = 0.40). A diet × day interaction (P < 0.01) was observed for daily rumination minutes per kg of DMI, NDF, peNDF4.0, and peNDF8.0. A diet × hour interaction (P < 0.01) was observed where CON cattle spent less time ruminating at 0800 and 1000 h in a 24 h period. Daily ruminal pH was greatest (P < 0.01) for COMBO, intermediate for SB20 and WDGS20, and least for CON. A diet × hour interaction (P < 0.01) was also observed for circadian ruminal pH, where pH was least for CON from 0800 to 1800 h. Relationships between peNDF, rumination behavior, and ruminal pH observed in this study suggest that SB and WDGS similarly enhance rumen buffering capacity when steam-flaked corn is replaced in the diet.

Levucell^® SB is a feed additive based on viable cells of a strain Saccharomyces cerevisiae marketed in three formulations: SB20 with a minimum concentration of 2 × 10¹⁰ CFU/g viable yeast cells and SB10 ME and SB Titan, both microencapsulated forms with a minimum concentration of 1 × 10¹⁰ CFU/g viable yeast cells. In 2014, EFSA was requested by the European Commission to re-evaluate the product when used as a zootechnical additive in feed for sows and weaned piglets. The safety of the additive for consumers, users, the environment and target animals and its efficacy for sows was established at that time. In that instance, the FEEDAP also concluded on the potential Levucell^® SB to improve growth of piglets based on one study where supplementation of the additive was done at the recommended dose of 2 × 10⁹ CFU/kg feedingstuffs and two at 1 × 10⁹ CFU/kg feedingstuffs, and considered that the effective dose was 2 × 10⁹ CFU/kg feedingstuffs. Two additional feeding trials in weaned piglets receiving the additive at 1 × 10⁹ CFU/kg feedingstuffs are the subject of this assessment. Due to the high mortality, one of the studies was not considered. In the remaining study, the supplementation of Levucell^® SB to weaned piglets at 1 × 10⁹ CFU/kg feed resulted in a significant improvement of feed to gain ratio. Taking into account the two trials from the initial application which showed significant effects at 1 × 10⁹ CFU/kg feed, the FEEDAP Panel concludes that Levucell^® SB has the potential to improve performance of weaned piglets when added to feed at 1 × 10⁹ CFU/kg complete feedingstuffs. Results of the efficacy studies can be applied to any of the three available formulations when used to deliver the same dose.