antibiotics, administration, nursery, pigs
This experiment was conducted to determine the influence of the route of antibiotic administration (in-feed vs. in-water) on nursery pig growth performance. A total of 2,592 pigs (L337 × 1050, PIC Hendersonville, TN; initially 14.5 lb) were used in a 28-d trial. Pigs were weaned at 21 d of age and placed in a commercial research facility with 27 pigs per pen. After a 7-d pre-trial period, pens of pigs were assigned to weight blocks in a randomized complete block design. There were 12 replications per treatment with pen as experimental unit for in-feed medication treatments and a pair of pens as the experimental unit for water medication treatments. The six treatments included a control (no medication), chlortetracycline (CTC) provided via feed or water to achieve 9.98 mg/lb body weight (BW), tiamulin in feed (2.27 mg/lb BW) or water (10.43 mg/lb BW), or a combination of CTC and tiamulin in feed. Experimental treatments were provided for 14-d followed by a 14-d period without medication. For statistical analysis, the interaction of antibiotic type × route of administration was tested in a 2 × 2 factorial with main effect of antibiotic type (CTC or tiamulin) and route of administration (in-feed or in-water). Pairwise comparisons were also made between the control and all individual treatments. From d 0 to 14 (P < 0.05), d 14 to 28 (P < 0.10), and d 0 to 28 (P < 0.05) there was an antibiotic × route of administration interaction observed for average daily gain (ADG). The interactions were a result of pigs fed diets containing CTC having improved (P < 0.05) ADG compared to CTC in-water, whereas pigs provided tiamulin in-water exhibited improved ADG compared with tiamulin in feed. There was an antibiotic × route of administration interaction observed for feed-to-gain ratio (F/G) from d 0 to 14 and 0 to 28. Pigs provided tiamulin in the feed had the poorest F/G, whereas F/G was not different among the other treatments. Providing CTC in the feed or water or tiamulin in the water improved (P < 0.05) ADG compared to pigs fed the control diet. Providing either CTC or tiamulin in the feed increased (P < 0.05) average daily feed intake (ADFI) as compared with providing the antibiotics in water. Pigs fed antibiotics in the feed had increased (P < 0.05) ADFI compared to the control with those provided antibiotics in the water being marginally greater (P < 0.10) in ADFI than the control. For ADG (d 0 to 28), pigs provided CTC in feed, tiamulin in the water, or the combination of CTC and tiamulin in the feed during the treatment period had increased ADG (P < 0.05) compared to pigs fed the control diet. For ADFI, there was no evidence of an interaction or main effects; however, when compared to the control, pigs provided CTC in-feed, tiamulin in-water, or the combination in the feed all had increased ADFI. In summary, providing CTC in feed with or without tiamulin or tiamulin in the water improved nursery pig growth performance.
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Hutchens, W. M.; Tokach, M. D.; Dritz, S. S.; Woodworth, J. C.; DeRouchey, J. M.; Goodband, R. D.; Calderón, H. I.; Habib, K.; Ishengoma, V.; Nagaraja, T. G.; and Amachawadi, R. G.
"Evaluating the Route of Antibiotic Administration and its Effect on Nursery Pig Growth Performance,"
Kansas Agricultural Experiment Station Research Reports: