Determining the Impact of By-O-Reg+ in Diets with or without a Feed Grade Antibiotic on Growth Performance of Nursery Pigs

Authors

L. L. Thomas, Kansas State University, ManhattanFollow
J. C. Woodworth, Kansas State University, ManhattanFollow
R. D. Goodband, Kansas State University, ManhattanFollow
J. M. DeRouchey, Kansas State University, ManhattanFollow
M. D. Tokach, Kansas State University, ManhattanFollow
S. S. Dritz, Kansas State University, ManhattanFollow

Keywords

antibiotics, nursery pigs, oregano

Abstract

A total of 717 nursery pigs (PIC C-29 × 28 and PIC L3-1050 × 1040, initially 12.48 ± 0.10 lb) from two consecutive nursery groups were used in a 35-d growth study. The objective was to determine the impact of increasing levels of By-O-Reg+ in diets with or without 50 g/ton Carbadox. By-O-Reg+ is a unique mixture of essential oils primarily based on oregano. It utilizes encapsulation technology to stabilize the essential oils and is suggested to have antimicrobial-like properties. The present study evaluated growth performance of nursery pigs fed 1 of 6 dietary treatments that were arranged as a 2 × 3 factorial with main effects of antibiotic (none vs. 50 g/ton Carbadox) and By-O-Reg+ (0, 1, or 2 lb/ton). Experimental diets were fed for 21 d and then a common diet was fed for the final 14 d. Pens of pigs (5 barrows and 5 gilts) were balanced by initial BW and randomly allotted to treatments, with 12 replications (pens) per treatment. During the period when treatments were fed (d 0 to 21) no interactions were observed between By-O-Reg+ and Carbadox. Increasing By-O-Reg+ decreased, and then increased (quadratic P = 0.016) F/G. Pigs fed diets with Carbadox had improved (P<0.007) ADG, ADFI, and F/G. From d 21 to 35, when a common diet was fed, pigs previously fed diets with Carbadox had increased (P = 0.007) ADFI. However, an interaction (linear, P = 0.039) was observed with pigs previously fed diets without Carbadox showing decreased ADFI as By-O-Reg+ increased; whereas when pigs were previously fed diets containing Carbadox, ADFI increased as the level of By-O-Reg+ increased. For the overall period (d 0 to 35), an interaction (linear, P = 0.031) was observed for ADFI with pigs fed diets without Carbadox having decreased ADFI as By-O-Reg+ increased; whereas when pigs were fed diets containing Carbadox, ADFI increased with increasing By-O-Reg+. No main effects of By-O-Reg+ were observed for the overall data; however, adding Carbadox for 21 d after weaning improved (P<0.015) ADG, ADFI, and final BW and tended to improve (P<0.087) F/G. Overall, this study confirms the benefit of including a feed grade medication in nursery pig diets to improve growth performance. Increasing By-O-Reg+ in diets elicited few changes in performance, but during the test period the pigs fed 1 lb/ton of By-O-Reg+ had better F/G than those fed none or the 2 lb/ton of By-O-Reg+. More research is needed to confirm if 1 lb/ton inclusion of By-O-Reg+ is the appropriate dose to elicit the best response.

Recommended Citation

Thomas, L. L.; Woodworth, J. C.; Goodband, R. D.; DeRouchey, J. M.; Tokach, M. D.; and Dritz, S. S. (2015) "Determining the Impact of By-O-Reg+ in Diets with or without a Feed Grade Antibiotic on Growth Performance of Nursery Pigs," Kansas Agricultural Experiment Station Research Reports: Vol. 1: Iss. 7. https://doi.org/10.4148/2378-5977.1140