Abstract

Thirty-two Hereford x Simmental steers (250.0 ± 15 kg Initial BW) were assigned to four dietary treatments in a completely randomized design (4 steers/pen, 2 pens/treatment) in order to evaluate the effects of supplementing Monensin (MON; Rumensin; Elanco Animal Health, Greenfield, IN) in comparison and in combination (CMB) with a proprietary Probiotic blend (PRO; MultSacch®, Biomart Nutrição Animal Imp. and Exp. Ltda.) on the growth performance, feed efficiency, and on cost of gain. Individual feed intake was monitored using a GrowSafe System (GrowSafe Systems Ltd. Calgary, AB, Canada) and weights were recorded weekly for a 90d growth data period. Supplementation with PRO and CMB both increased Gain:Feed (G:F) by 6% with respect to control (CON) steers (P = 0.01). No treatment effects were detected in initial body weight (IBW), final body weight (FBW), or average daily gain (ADG) (P > 0.05). DMI was lowest in CMB steers (P = 0.04), and this same group had the lowest cost of gain (P < 0.001). Present findings indicate that when compared with MON, under these experimental conditions PRO seems to be just as effective in stabilizing intraruminal milieu and increasing ruminal fiber utilization when steers are fed rapidly fermentable carbohydrate grain-based diets, thus improving feed efficiency without the need of MON supplementation. However, combined use of PRO and MON results in the lowest cost of gain (P = 0.03). Further experimentation is required to ascertain the effect substituting MON with different mixtures of Probiotics will have long term on cattle growth performance and profitability.

Keywords: Yeast; Probiotics; Monensin; Feedlot Cattle

References

1. Ghazanfar S., et al. “Probiotic Yeast: Mode of Action and Its Effects on Ruminant Nutrition”. In: Yeast-Industrial Applications, IntechOpen (2017): 179-202.
2. Schelling GT. “Monensin mode of action in the rumen”. Journal of Animal Science6 (1984): 1518-1527.
3. Russell JB and Strobel HJ. “Effect of ionophores on ruminal fermentation”. Applied and Environmental Microbiology1 (1989): 1-6.
4. Stock RA., et al. “Effect of monensin and monensin and tylosin combination on feed intake variation of feedlot steers”. Journal of Animal Science1 (1995): 39-44.
5. Silva L., et al. “Supplementing a yeast-derived product to enhance productive and health responses of beef steers”. Animal: An International Journal of Animal Bioscience8 (2018): 1576-1583.
6. Chaucheyras-Durand F., et al. “Use of Yeast Probiotics in Ruminants: Effects and Mechanisms of Action on Rumen pH, Fibre Degradation, and Microbiota According to the Diet, Probiotic in Animals, Everlon Cid Rigobelo”. IntechOpen (2012).
7. Newbold CJ., et al. “The stimulation of rumen bacteria by Saccharomyces cerevisiae is dependent on the respiratory activity of the yeast”. Journal of Animal Science1 (1993): 280.
8. Wagner JJ., et al. “Meta-analysis examining the effects of Saccharomyces cerevisiae fermentation products on feedlot performance and carcass traits”. The Professional Animal Scientist2 (2016): 172-182.
9. Jiao PX., et al. “Comparison of non-encapsulated and encapsulated active dried yeast on ruminal pH and fermentation, and site and extent of feed digestion in beef heifers fed high-grain diets”. Animal Feed Science and Technology 228 (2017): 13-22.
10. Pancini S., et al. “Supplementing a yeast-derived product to feedlot cattle consuming monensin: Impacts on performance, physiological responses, and carcass characteristics”. Livestock Science 232 (2020): 103907.
11. Swyers KL., et al. “Evaluation of Saccharomyces cerevisiae fermentation product as an alternative to monensin on growth performance, cost of gain, and carcass characteristics of heavy-weight yearling beef steers”. Journal of Animal Science6 (2014): 2538-2545.