Narasin effects on energy, nutrient, and fiber digestibility in corn-soybean meal or corn-soybean meal-dried distillers grains with soluble diets fed to 16-, 92-, and 141-kg pigs

Authors: Kerr, Brian; Trabue, Steven - Steve; ANDERSEN, DANIEL - Iowa State University

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/7/2017
Publication Date: 8/10/2017
Publication URL: http://handle.nal.usda.gov/10113/5927844
Citation: Kerr, B.J., Trabue, S.L., Andersen, D.S. 2017. Narasin effects on energy, nutrient, and fiber digestibility in corn-soybean meal or corn-soybean meal-dried distillers grains with soluble diets fed to 16-, 92-, and 141-kg pigs. Journal of Animal Science. 95(9):4030-4036. https://doi.org/10.2527/jas.2017.1732.

Interpretive Summary: Lipophilic ionophores allow for attachment to cell membranes of bacteria, with a higher affinity towards Gram-positive bacteria, fungi, and coccidia than towards Gram-negative bacteria. While there have been several studies evaluating the impact of ionophores on growing pig performance, there is limited information on the impact of a newly approved ionophore on the digestibility of energy and nutrients, or on growth in nursery, grower, and finishing pigs, and whether it differs depending on the fiber concentration of the diet. Consequently, the current study was conducted to determine the impact of narasin on the digestibility of energy and nutrients in nursery, grower, and finisher pigs fed a corn-soybean meal or a corn-soybean meal-distillers dried grains with solubles diet. In general, the data from these experiments indicate that narasin interacted with and had its largest effect on pig performance and GE or nutrient digestibility in 9 to 23 kg pigs compared to pigs weighing greater than 80 kg. This information is important for nutritionists at universities, feed companies, and pig production facilities for determining the ability of an ionophore to affect energy and nutrient digestibility in pigs, and on its ability to affect pigs performance; both of which provides a basis from which to assess its economic value.

Technical Abstract: Three experiments were conducted determine the effect of narasin on growth performance, and on GE and nutrient digestibility in nursery, grower, and finishing pigs fed either a corn-soybean (CSBM) diet or a CSBM diet supplemented with distillers dried grains with solubles (DDGS), in combination with either 0 or 30 mg narasin/kg of diet. In Exp. 1 (64 gilts, initial BW = 9.0 kg, SD = 1.0 kg) and Exp. 2 (60 gilts. initial BW = 81.1 kg, SD = 6.1 kg), gilts were allotted into individual pens and fed their experimental diets for 24 and 21 d, respectively. On the last 2 d of each experiment, fecal samples were collected to assess apparent total tract digestibility (ATTD) of GE and various nutrients. In Exp. 3, 2 separate groups of 24 gilts (initial BW = 145.1 kg, SD = 7.8 kg) were allotted to individual metabolism crates and fed their experimental diets for 30 d prior to a time-based 6-d total fecal collection period to assess GE and nutrient digestibility. In Exp. 1, there was an interaction between diet type and narasin addition for G:F and for many of the ATTD coefficients measured. When narasin was supplemented to the CSBM diet, ATTD of GE, DM, C, S, phosphorus, NDF, and ADF was either not changed or reduced; while narasin supplemented to DDGS diets caused these same ATTD parameters to increase (interaction, P = 0.05). Even though ADG and ADFI were not affected, GF was improved in pigs fed the CSBM diet with supplemental narasin, but was reduced in pigs fed the DDGS diet with supplemental narasin (interaction, P < 0.05). In Exp. 2, there was an interaction between diet type and narasin supplementation only for ATTD of Ca (interaction, P < 0.01), in that narasin supplementation did not change the ATTD of Ca in pigs fed the CSBM diet, while narasin supplementation reduced the ATTD of Ca in pigs fed the DDGS containing diet. In Exp. 3, there was an interaction between diet and narasin only for ATTD of C (interaction, P < 0.01) in that narasin supplementation resulted in an increase ATTD of C in pigs fed the CSBM diet, while narasin supplementation to the DDGS containing diet resulted in a reduced ATTD of Ca. In general, the data indicate that narasin interacted with and had its largest effect on pig performance and GE or nutrient digestibility in 9 to 23 kg pigs compared to pigs weighing greater than 80 kg. The data also indicate that addition of DDGS reduced GE, DM, Ca, and N digestibility, regardless of BW.