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

Abstract

Three experiments were conducted to 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 meal (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 when narasin was supplemented to DDGS diets, these same ATTD parameters were increased (interaction, P ≤ 0.05). Even though ADG and ADFI were not affected, G:F] 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 increased 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 the addition of DDGS reduced GE, DM, Ca, and N digestibility, regardless of BW.

Impact of narasin on manure composition, microbial ecology, and gas emissions from finishing pigs fed either a corn-soybean meal or a corn-soybean meal-dried distillers grains with solubles diets

“…This is not surprising given that characterization of manure bacteria and composition in a complex matrix (Cotta et al, 2003;Trabue et al 2016b) and the selection of the manure storage tank and length of storage (Trabue et al 2016a) can have profound effects on the data obtained making interpretation of the results challenging. In the current experiment, narasin had minimal effect on manure composition (Table 2) and this is supported by Kerr et al (2017) who, using the same pigs, reported that energy or nutrient digestibility in finishing pigs was unaffected by narasin supplementation. The greater amount of manure nutrients as a percentage of animal intakes due to narasin supplementation (Table 3) is best understood from the perspective that narasin inhibits gross biomass functions as seen in lower degradation rates of total and volatile solids of manure treated with and without narasin (Andersen and Regan, 2014), but some more specific functions are unaffected and this difference may be due in part to the level of functional redundancy for that particular function.…”

“…After manure sampling, the manure in the tanks was dumped and the tanks cleaned for the second group of pigs. Additional detail on the effects of diet and narasin on energy, nutrient, mineral, and fiber digestibility are presented elsewhere (Kerr et al, 2017).…”

“…Each of the 2 trials consisted of a 48-d feces and urine collection into 1 tank per pig, with 12 individually penned gilts per treatment. Diets with DDGS contained 30.34% DDGS while the narasin diets contained 30 mg narasin/kg diet.. Gutierrez et al, 2013Gutierrez et al, , 2014aGutierrez et al, , 2014bKerr et al, 2013Kerr et al, , 2015aKerr et al, , 2015bKerr et al, , 2017Wu et al, 2016aWu et al, , 2016bWu et al, , 2016c and was not an objective of the current experiment. That said, a change in energy or nutrient digestibility (represented by a change in fiber digestibility in this experiment), can have (Kerr et al, 2006;Ziemer et al, 2009;Trabue and Kerr, 2014;Trabue et al, 2016b;Van Weelden et al, 2016a, and data obtained from this experiment are no exception.…”

Dietary composition and particle size effects on swine manure characteristics and gas emissions

“…This is supported by previously published research on diet particle size and pig performance (Hancock & Behnke, 2001; Liu, Souza, Baidoo, & Shurson, 2012). The current data are also in agreement with others (Kerr, Ziemer, Trabue, Crouse, & Parkin, 2006, 2015, 2017, 2018; Trabue & Kerr, 2014), indicating that if diets with a moderate amount of fiber are balanced for energy, pigs will perform comparably to pigs fed a low‐fiber diet.…”

“…This, however, was not noted in the current trial, where the S content of manures from DDGS and CSBM diets were both approximately 0.094 g L −1 and where SH contained only 0.07 g S L −1 . The impact of diet particle size on manure composition has not been thoroughly studied, but it would be assumed that any diet composition or diet processing method that increased nutrient digestibility by an animal would increase nutrient retention, thereby reducing its “input” in the manure storage system (Kerr, Trabue, & Andersen, 2017, 2018). As reported in pigs fed the same diets as used in the current study (Saqui‐Salces, Luo, Urriola, Kerr, & Shurson, 2017), decreasing particle size resulted in an increase in the digestibility of DM (used as a surrogate for C), and N and S, which, in the data reported herein, corresponded to a decrease in manure NH 4 –N, C, and N but not manure sulfide or S.…”