Effect of roller mill configuration on growth performance of nursery and finishing pigs and milling characteristics1

Abstract

Three experiments were conducted to evaluate the effects of roller mill configuration on growth performance of nursery and finishing pigs, feed preference, and feed mill throughput. The four experimental treatments included corn ground through a roller mill using two, three, four sets of rolls in a fine-grind configuration, or four sets of rolls in a coarse grind configuration. The same roller mill was used for all configurations with the appropriate lower rolls completely open when using the two or three roll pair configurations. Across all studies, mean particle size averaged approximately 540, 435, 270, and 385 µm for the four roller mill configurations, respectively. In Exp. 1, 320 pigs (DNA 400 × 200, initially 10.7 ± 0.27 kg BW) were randomly allotted to treatments with five pigs per pen and 16 pens per treatment in a 21-d growth trial. While there were no evidence of differences observed for ADG or ADFI, pigs fed corn ground using the 4-high coarse configuration had a marginally significant (P = 0.091) improvement in G:F compared with those fed with the 2-high configuration, with others intermediate. In Exp. 2, 90 pigs (PIC 327 × 1050, initially 12.1 ± 0.25 kg BW) were randomly allotted to one of three diet comparisons to determine feed preference between the 2-high, 4-high fine, and 4-high coarse configurations. When given a choice, pigs consumed more (P < 0.05) of the diet containing corn ground through the 2-high roller mill (67%) or 4-high coarse configuration (63%) compared with corn ground through the 4-high fine configuration. In Exp. 3, 922 finishing pigs (PIC TR4 × [FAST Large white × PIC Line 2], initially 40.1 ± 0.36 kg BW) were used in a 97-d experiment with pens of pigs randomly allotted by initial BW to the same experimental treatments used in Exp. 1. There were 21 pigs per pen and 11 pens per treatment. Pigs fed corn ground with the 2-high configuration had greater (P < 0.05) ADG compared with those fed corn ground using the 3-high configuration. Pigs fed corn ground with the 4-high fine configuration had the poorest (P < 0.05) ADG. No differences were observed in G:F. Grinding rate (tonne/h) was greatest (P < 0.05) for the 4-high coarse configuration, while net electricity consumption (kWh/tonne) was lowest (P < 0.05) for the 2-high configuration and greatest for the 4-high fine configuration. In summary, nursery pig G:F tended to be greatest using the 4-high coarse configuration, and finishing pig ADG was maximized using the 2- and 4-high coarse configurations.

Corn physical characteristics on piglet performance

“…The increase in grinding intensity obtained by reducing the screen hole diameter (screen used to surround the grinding chamber in hammer mill) makes it difficult for the corn to leave the crushing chamber in the grain process, with a consequent greater number of hammer impacts on the corn particles, which leads to reduced PS and GSD (Table 2). This reduction in GSD with the reduction in PS is a relatively common behavior and has already been reported by Paiano et al (2014); Rojas and Stein (2015); Chiodelli, Folador, Boiago, Carvalho, and Paiano (2018) and Gebhardt et al (2018); said behavior is associated with grain reprocessing, which is characterized by reduced particle size variability.…”

“…Some studies such as the one carried out by Ball et al (2015), which characterized feeds as finely or coarsely ground, did not observe any effect on these variables in the finishing phase. Likewise, Gebhardt et al (2018), in a study of corn ground in a roller mill, with PS ranging between 267 and 525 µm, did not verify any effect on DFI and DWG for piglets in the nursery phase. However, Huang et al (2015), in a study with weaned piglets, detected an improvement in DFI and DWG with increasing corn grinding intensity (PS reduction from 405 to 285 µm), and Gebhardt et al (2018) found negative effects on intake and gain in the finishing phase of swine, with a PS reduction from 561 to 285 µm.…”

“…Corn grinding close to 400 µm is common in piglet nutrition (Nemechek et al, 2016), and greater reductions tend to be beneficial from the point of view of digestibility. However, excessively fine grinding increases processing time, energy expenditure with grinding, and may compromise the fluidity of the diets due to the increase in their angle of repose (Chiodelli et al, 2018;Gebhardt et al, 2018). In adult animals, excessively fine particle size can increase the incidence of gastric ulcerations (Maxwell et al, 1970;Potkins, Lawrence & Thomlinson, 1989).…”

The influence of particle size of Enogen Feed corn and conventional yellow dent corn on nursery and finishing pig performance, carcass characteristics and stomach morphology

“…Samples were analyzed both with (5 g) and without a dispersing agent (Gilson Company, Inc., Lewis Center, OH) using two separate stainless-steel sieve stacks (13 sieves each) to prevent residual dispersing agent from affecting results. Both sieve stacks contained agitators and were placed in the Ro-Tap (Model RX-29, W. S. Tyler Industrial Group, Mentor, OH) machine for 15 min, using the same sieve and agitator configurations as Gebhardt et al (2018) .…”

Strategies to minimize fallback pigs in the nursery

“…Pigs prefer course ground corn and pellets with a larger diameter. 20,36,37 In pens where lightweight or removal pigs are housed, an intensive care diet with highly palatable ingredients may need to be provided before the starter diet to encourage earlier feed intake.…”