Feed Disappearance Research Articles

Effects of including Sweet Bran or modified distillers grains in the diet of feedlot steers and sorting at terminal implant on growth performance, feeding behavior, and liver abscess occurrence.

The objectives were to assess the effects of dietary Sweet Bran (Cargill Corn Milling, Blair, NE) on performance and feeding behavior of feedlot steers and determine if terminal implant pen sorting affects performance, feeding behavior, and liver abscess (LA) rate. Two hundred sixteen Angus-cross steers (253 ± 18 kg) were stratified by body weight (BW) to 36 pens. From d 0 to 60, diets contained 40% Sweet Bran (SWBR) or 25% modified distiller’s grains and 15% dry rolled corn (MOD; n = 18 pens/treatment). On d 60, steers began transition within treatments to finishing diets containing 25% Sweet Bran or 25% modified distiller’s grains (MDGS). On d 111, half of the pens for each dietary treatment were re-stratified by BW to pens (SORT) while the other half were returned to original pens (NOSORT; n = 9 pens/treatment). Steer BW and pen dry matter intake (DMI) were recorded monthly. Rate of feed disappearance was determined on d 5/6, 53/54, 104/105, and 117/118. Pen was the experimental unit for all analyses. The model included the fixed effect of diet for all pre-sort analyses; post-sort analyses included the fixed effects of diet, sort, and the interaction and the random effects of pen and the interaction of diet and pen. On d 60, SWBR had greater BW than MOD (P = 0.05), and SWBR had a greater average daily gain (ADG) from d 0 to 60 (P = 0.05). Though there were no differences after d 28, SWBR had greater DMI d 0 to 28 (P = 0.05). From d 60 to 88, SWBR tended to have lesser ADG than MOD (P = 0.09). Post-sort (d 111 to 196), SWBR tended to have lesser ADG than MOD (P = 0.06), and SORT had a greater rate of feed disappearance than NOSORT (d 117/118; P = 0.01); there were no differences on other dates (Diet: P ≥ 0.38). For final BW, there was a tendency for MOD to be greater than SWBR, and SORT tended to be greater than NOSORT (Diet: P = 0.06; Sort: P = 0.10). Pre- and post-sort ruminal pH had no treatment by day differences (P ≥ 0.77). LA incidence averaged 25%, though rate was not affected by diet, sorting, or the interaction (P ≥ 0.16). Overall, there were no dietary differences in feed disappearance rates, though SORT steers had greater rate of feed disappearance than NOSORT steers on d 117/118. Nominal differences in feeding behavior were noted and including Sweet Bran in the diet was beneficial in the growing period as cattle adjusted to the feedlot.

Effect of increasing zinc supplementation on post-transit performance, behavior, blood and muscle metabolites, and gene expression in growing beef feedlot steers.

Fifty-four Angus-cross steers (297 kg ± 12) were stratified by body weight (BW) to pens (six steers per pen) to determine the effects of supplemental Zn on posttransit growth performance and blood and muscle metabolites. Dietary treatments started 25 d before trucking: control (CON; analyzed 54 mg Zn/kg DM), industry (IND; CON + 70 mg supplemental Zn/kg DM), and supranutritional Zn (SUPZN; CON + 120 mg supplemental Zn/kg DM). Supplemental Zn was bis-glycinate bound Zn (Plexomin Zn; Phytobiotics North America, Cary, NC). On day 0, steers were loaded onto a commercial trailer and transported in 18 h (1,822 km). Individual BW was recorded on days –26, –25, –1, and 0 (pre-transit), 1 (posttransit), 6, 27, and 28. Blood was collected on days –1, 1, 6, and 27. Longissimus thoracis biopsies were collected on days –1, 1, and 28. Daily individual feed disappearance was recorded via GrowSafe bunks. Data were analyzed using Proc Mixed of SAS with fixed effect of diet and steer as the experimental unit (growth performance, blood: n = 18 steers per treatment; muscle: n = 12 steers per treatment). Individual initial BW was used as a covariate in BW analysis. Contrast statements to test linear, quadratic, and Zn effects were used to analyze performance and blood parameters. Repeated measures analysis was used for posttransit DMI recovery and weekly posttransit DMI and Zn intake with the repeated effect of time. MetaboAnalyst 5.0 was utilized for statistical analysis of day 1 (off truck) muscle metabolites. Plasma Zn linearly increased due to Zn on days 1, 6, and 27 (P = 0.01), and off-truck (day 1) serum lactate increased over day –1 by 20%, 0%, and 20% in CON, IND, and SUPZN, respectively (Quadratic: P = 0.01). Muscle lactate tended to increase posttransit in CON and IND (P ≤ 0.07) but not SUPZN. Muscle metabolites relating to amino acid and nitrogen metabolism were increased in all treatments posttransit (P ≤ 0.02), and alanine-glucose cycle metabolites tended to increase in CON and IND (P ≤ 0.07). Steers supplemented with Zn recovered pretransit DMI quicker than CON (by d 2: P = 0.01), while IND had greater overall posttransit DMI than CON with SUPZN intermediate (P = 0.04), and Zn-fed steers had greater ADG posttransit (P = 0.04). Zinc supplementation mitigated muscle or serum lactate increases due to transit and increased posttransit ADG.

Impact of water flow rate on finishing pig performance.

A survey of 23 South Dakota pork producers in 2019 reported that 68% of the waterers in finishing barns had water flow rates above the recommended rate of 500–1,000 mL/min. The objective of the two studies was to determine the impact of water flow rate on finishing pig performance in the summer months. Study 1 used a total of 396 pigs in two groups in a 77-day trial (35.0 to 104.3 kg BW) with 6 pigs/pen and 1 cup waterer/pen. Study 2, conducted in a commercial style barn, used a total of 1,227 pigs in an 84-day trial (60.9 to 117.4 kg BW) with 26 pigs/pen and 2 cup waters/pen. Pens were assigned to one of three water flow rates (high, medium, low) based on the 3-hole settings of the water nipples (2.0, 1.0, and 0.8 mm; n = 22 and 16 pens/treatment for Study 1 and 2, respectively). Room temperature, outside temperature and relative humidity were recorded daily for both studies. In Study 1, water disappearance was recorded daily, and individual pen water flow rates were recorded every two weeks. At every diet phase change (26 ± 2.6 days), feed disappearance and individual pig body weights were recorded. Water flow rates averaged 1856 ± 188, 906 ± 214, 508 ± 100 mL/min for high, medium, and low flow settings, respectively. In Study 2, individual pen water flow rate, water disappearance, BW, and feed disappearance were recorded every two weeks. Water flow rates averaged 1115 ± 98, 906 ± 209, and 605 ± 203 mL/min for high, medium, and low flow settings, respectively. In both studies, there were no differences in final BW, cumulative ADG, or G:F. Due to the variability of water flow rate within a setting, data was further analyzed using regression with flow rate as the independent variable. Apart from average daily water disappearance (adj. R2 = 0.87), there was a low relationship between pig performance and water flow rate (adj. R2 < 0.09). The low R2 values associated with pig performance and the high association with water disappearance suggests that water flow rate above current recommendations has little impact on finishing pig performance but does contribute to water wastage and its associated costs.

255 Impact of Water Flow Rate on Finishing Pig Performance Under Commercial Conditions

Abstract A survey of South Dakota pork producers in 2019 reported that 68% had water flow rates above the recommended rate of 500-1,000 mL/min. The objective of this study was to determine the impact of water flow rate on finishing pig performance during from June to September in a commercial barn. A total of 1,227 mixed sex pigs (61 ± 4.38 kg) at 8-weeks post-wean were utilized in an 84-d trial with 26 pigs/pen and 2 cup waterers/pen. Pens were assigned to 1 of 3 water flow rates (high, medium, low) based on the 3-hole diameter of the water nipples (2.0, 1.0, 0.80 mm; n = 16 pens/setting). Individual pen water flow rate, water disappearance, BW, and feed disappearance were recorded every 2 weeks. Carcass data was collected at the conclusion of the trial. Water flow rates averaged 1,565±96, 1,115±265, and 605±203 mL/min for high, medium, and low flow rates, respectively. Ambient temperature ranged from 4 to 37 °C. There was no difference in growth performance based on means separation test. Due to variability of water flow rate within a setting, data was further analyzed using regression with flow rate as the independent variable. There was a positive quadratic relationship (P &amp;lt; 0.05) for daily water disappearance (adjR2 =0.87) and daily gain (adjR2 =0.11) with water flow rate and a tendency for positive linear relationship between final BW (P = 0.07, adj. R2 = 0.06) and flow rate. Feed conversion had a negative cubic relationship with water flow rate (P &amp;lt; 0.05, adj. R2 = 0.20) and no relationship between hot carcass weight or average daily feed intake and water flow rate. The low R2 values associated with pig performance and high association with water disappearance suggest that excess water flow rate has a low impact on finishing pig performance but contributes to water wastage and its associated costs.

PSVI-9 Effects of Phytogenic Feed Additives on Growth Performance in Nursery Pigs

Abstract Two experiments were conducted to demonstrate the effects of adding a phytogenic feed additive (PFA; Digestarom Sow, BIOMIN America Inc.) on growth performance of nursery pigs compared with a carbadox feeding program. Newly weaned pigs were randomly allotted into a control (added carbadox) or PFA treatment. A total of 144 (6.10 ± 0.20 kg of BW, Exp. 1) and 600 pigs (6.18 ± 0.03 kg of BW, Exp. 2) were randomly allotted to 2 treatments. Pigs were fed three nursery diets over 42 d (Exp. 1) or 40 d (Exp. 2). Pigs were fed diets containing carbadox (CON, 25 g/ton in Exp. 1 and 50 g/ton in Exp. 2) from phase 1 to 2 and fed diets containing 0.015% PFA from phase 1 to 3 in both experiments. Body weight and feed disappearance were recorded at the end of each phase. Data were analyzed using the Mixed procedure of SAS. Pigs fed carbadox had a greater (P &amp;lt; 0.05) Gain:Feed in phase 1 (Exp. 1) and in phase 2 (Exp. 2), respectively. However, Gain:Feed of pigs fed PFA was greater (P &amp;lt; 0.05) than feeding carbadox in phase 3 in Exp. 2. No differences were found between the 2 treatments in either of the experiments in overall period. In conclusion, PFA (Digestarom Sow) supplementation resulted in similar growth performance when compared with a carbadox feeding program during the post-weaning period.

PSI-3 Effects of Increasing Dietary Arginine Supply on Pig Growth Performance Following Weaning Stress

Abstract Intestinal health has important implications for pig overall health status and growth performance. In this regard, arginine participates in important regulatory functions associated with nutrient metabolism, cell proliferation, and immune response that contribute to the maintenance of a functional intestinal tract. However, Current nutritional practices for weaned pigs do not consider the critical regulatory roles of arginine related to pig gut health and function. The objective of this study was to determine growth response of weaned pigs fed increasing levels of L-Arginine during the first weeks after weaning. A total of 225 weaned pigs (BW 5.8 ± 0.9 kg) were used in a randomized complete block design and assigned to 1 of 5 dietary treatments, with 9 replicate pens of 5 pigs. A basal diet was formulated to meet current arginine requirements (0.66% - NRC, 2012) and L-arginine was supplemented at 0.3, 0.6, 0.9, and 1.2%. Experimental diets were provided in meal form during phases 1 and 2 of a 3-phase nursery feeding program: Phase 1 (d 0-d 7), Phase 2 (d 8-d 21), and Phase 3 (d 22-d 42). A common diet was provided during phase 3. Feed disappearance and body weight were measured at d 7, 14, 21, and 42 after weaning. Through the first 3 weeks after weaning, increasing dietary arginine supply linearly improved (P ≤ 0.05) body weight (8.25 - 11.20 kg), average daily gain (Figure 1), average daily feed intake (251.53 - 387.75 g), and gain to feed ratio (0.60 – 0.66) of pigs. These beneficial effects persisted throughout phase 3, where arginine supplementation resulted in a linear improvement in pig overall growth performance. In addition, increasing arginine supply reduced the percentage of pigs that lost weight during the first week post-weaning by 29%. Overall, weaned pigs require more dietary arginine for optimal nursery performance, which includes reducing fall back pigs.

163 Peak-Infection Application of Increased SID Lysine:ME Diets Does Not Improve Disease Challenge Growth Performance

Abstract Increasing dietary SID Lys:ME augments growth performance of Porcine Reproductive and Respiratory Syndrome virus (PRRSV) challenged pigs when diets with greater SID Lys concentrations are in place at time of infection. Our objective was to evaluate the delayed implementation of increased SID Lys:ME diets post PRRSV challenge on pig performance. 491 grower pigs (45.8 ± 7.4 kg BW) were assigned to 1 of 3 dietary strategies (n = 16 pens/treatment, 10-11 pigs/pen). All pigs received a common diet from day post inoculation (dpi) -14 to dpi 21 (P1), that met SID Lys:ME recommendations. From dpi 21 to 77 (market body weight), dietary treatments were implemented in 2 phases (P2 and P3). The 2 dietary treatments were 2.23 g/Mcal (100%), 2.56 g/Mcal (115%), 2.90 g/Mcal (130%) in P2; and 1.92 g/Mcal (100%), 2.21 g/Mcal (115%), 2.49 g/Mcal (130%) in P3. On dpi 0, all pigs were inoculated with PRRSV. Pig BW, feed disappearance and feed efficiency were determined in each phase. Data were analyzed with pen as the experimental unit in a complete randomized design. During P1, ADG, ADFI, or G:F did not differ (P &amp;lt; 0.05). In P2 and P3, ADG, ADFI, or G:F did not differ between the 100%, 115% and 130% treatments (P &amp;gt; 0.10). Overall, ADG (0.90, 0.90 and 0.92 kg/d, P = 0.44) and ADFI (2.61, 2.57 and 2.57 kg/d, P = 0.48) did not differ between the 100%, 115% and 130% treatments, respectively. However, overall G:F was significantly higher for the 130% compared with the 100% and 115% treatments (0.36 versus 0.34 and 0.35, respectively; P = 0.021). Mortality was similar across treatments (P = 0.717). In conclusion, delayed feeding of diets with increased SID Lys:ME post infection was not beneficial to pig performance indicating this diet strategy needs to be in place near time of disease challenge.

160 The Compensatory Growth of Finishing Pigs Fed Increasing Dietary Lysine Following a Period of Nutrient Restriction

Abstract The objective of this experiment was to evaluate the degree of compensatory gain in finishing hogs when fed increasing levels of lysine during the re-alimentation period after being fed a restrictive 97% corn diet for 3 or 6 weeks. One hundred and forty mixed-sex pens (DNA Genetics, Columbus, NE) with a starting body weight of 73.5 ± 2.2 kg were blocked by starting bodyweight and assigned to a 2:3:1 factorial. Twenty replicates of seven treatments were comprised of 2 restriction lengths [3 weeks (3W) vs. 6 weeks (6W)], and 3 lysine inclusion levels at re-alimentation (Lys:ME: 100%, 110%, or 120% of the genetic margin over feed curve), and a control that remained nutrient unrestricted. Pen weight and feed disappearance were recorded at trial day zero and every 3-weeks until market. Whole pens were marketed when the average met 130 kg to evaluate the full re-alimentation period. Data were analyzed by pen (SAS 9.4, Cary, NC) with the fixed effects of restriction length and lysine level nested within restriction length. Control pigs were market weight (130 kg) on d 49 while pigs fed corn diets for 3 weeks or 6 weeks were significantly slower to market (57 and 69 d, respectively; P &amp;lt; 0.01). Overall average daily gain was significantly different between the control, 3W, and 6W groups (Control: 1.17, 3W: 0.99, 6W: 0.82; P &amp;lt; 0.01). Furthermore, overall average daily gain was significantly influenced by the lysine inclusion level during re-alimentation (Control: 1.17, 3W/100%: 0.98, 3W/110%: 0.99, 3W/120%: 1.01, 6W/100%: 0.81, 6W/110%: 0.83, and 6W/120%: 0.84 kg/d; P &amp;lt; 0.03). In conclusion, the use of 97% corn diets significantly reduced average daily gain and increased days to market. However, the use of diets in which the Lys:ME was greater than genetic recommendations after a period of nutrient restriction, resulted in increased compensatory growth.

105 The Impact of Lowering Floor Space Allowance and Dietary Energy Level on Finishing Pigs, from 65 Kg to Market, on Growth Performance

Abstract The objective of this experiment was to evaluate the impact of reducing floor space allowance in finishing hogs with a starting body weight (BW) of 65 ± 2 kg when fed high versus low energy diets on growth performance. Mixed-sex pens (n=88) with 24 ± 1 pigs per pen were blocked by starting BW to a randomized complete block design with eight treatments. These eight treatments formed a 2 x 4 factorial arrangement with 2 energy levels: low (LE, 3270 ±19 kcal/kg ME) vs. high (HE, 3392 ±19 kcal/kg ME) accomplished through fat inclusion; and 4 floor space allowances: 0.60, 0.63, 0.65, 0.67 m2 per pig. Assigned floor space was adjusted by moveable gates in the rear of the pen, which were corrected at each pig removal until the marketing phase. Pen weight and feed disappearance were measured for 2 phases at d 0, 29, and 48 to calculate average daily gain (ADG), average daily feed intake (ADFI), and gain to feed ratio (GF). Data were analyzed by pen (SAS 9.4, Cary, NC) with the repeated measure of phase, and the fixed effects of floor space allowance, dietary energy, and the interaction between. For the overall trial, decreased floor space had no effect (P &amp;gt; 0.1) on ADG, ADFI, or GF (0.36, for all). Energy had a significant effect (P &amp;lt; 0.01) on ADFI (3.17 vs 3.12 kg for LE and HE, respectively) and GF (0.35 and 0.36 for LE and HE, respectively), and tended to impact ADG (1.12 vs 1.13 kg, for LE and HE, respectively; P = 0.08). In conclusion, lowering floor space allowance from 0.67 m2 down to 0.60 m2 did not affect the growth performance of pigs starting at 65 kg. Pigs fed HE diets had 2.86% better GF compared with pigs fed LE diets, however had similar growth and body weight.

PSVIII-14 Zinc Oxide Augments Early Nursery Pig Feed Intake

Abstract Pharmacological concentrations of zinc (Zn) are commonly fed in the nursery to benefit early post-weaning performance and reduces scours. Therefore, our objective was to determine the effect of pharmacological Zn on post-weaning pig daily feed intake and performance. Three-hundred weaned pigs (5.7 ± 1.03 kg BW) were selected and allotted to 1 of 3 dietary treatments (n = 10 pens/treatment, 10 pigs/pen). Diets were fed over 2 phases (phase 1: d 0-7, phase 2: d 8-21) and consisted of: 1) Control diet with no growth promoting additives, CON; 2) CON + 3,000 ppm Zn and 200 ppm Cu (phase 1), no pharmacological minerals in phase 2, ZC1; and 3) CON + 3,000 ppm Zn and 200 ppm Cu (phase 1), CON + 2,000 ppm Zn and 200 ppm Cu (phase 2); ZC2). Bodyweights were collected at d 0, 7, and 21. Feed disappearance was recorded daily from d 0-14, and within phase. In phase 1, ZC1 and ZC2 pigs had 29% greater feed consumption compared with the CON pigs (0.09, 0.09, 0.07 kg/d; P &amp;lt; 0.0001). Within 2 d of phase 2 diet change, feed intake of the ZC1 pigs sharply decreased to the same level of the CON pigs, while ZC2 pigs consumed 29% more (P &amp;lt; 0.05). In phase 1, ZC1 and ZC2 pens had increased ADG compared with CON pigs (P &amp;lt; 0.001). In phase 2, ADG was 14% greater in the ZC2 compared with ZC1 and CON pigs (P = 0.023). Overall, ADG was 15% greater in the ZC2 pigs and ADFI was 13 and 24% higher than ZC1 and CON pens, respectively (P &amp;lt; 0.05). In conclusion, early post-weaning feed intake was augmented with pharmacological levels of Zn. These data suggest that pharmacological Zn potentially enhances voluntary feed intake regulation in pigs.

PSIV-15 Impact of Wean Age and SID Lysine Level on Performance in Lactation

Abstract With genetic improvement, sows are having larger litters and nursing more pigs. The wean age of these piglets can impact sow feed intake and piglet wean weight. Additionally, Lys level can impact sow and piglet growth. This study was performed to assess whether the addition of greater standardized ileal digestible (SID) Lys improves sow and litter performance for 2 wean ages. Four hundred thirty-two DNA F1 females (average parity 2.4) were randomly allotted within group and entry weight at farrowing to 1 of 4 dietary treatments. Treatments were arranged in a 2 x 4 factorial with wean age (15.5 and 24.5 d) and lactation diet SID Lys (0.87, 0.94, 1.02 and 1.10%). Sows were weighed entering and exiting the farrowing room. Feed disappearance was calculated as the total amount of feed provided to the sow during lactation. A post-farrow weight model was utilized to assess true weight loss in lactation. Litters were standardized within 24 h of birth. Data were analyzed as a randomized complete block design with fixed effects of SID Lys and wean age, and random effect of replicate. Average daily feed intake was increased (P &amp;lt; 0.05) in the sows weaning older age compared with younger age piglets (6.52 vs. 5.87 kg respectively). There was a tendency (P &amp;lt; 0.10) for an interaction between wean age and maternal Lys level on piglet wean weight as higher Lys increased wean weight (0.29 kg) in the older wean age but had no improvement in the younger wean age. Sow weight loss was decreased (P &amp;lt; 0.05) in sows weaning younger piglets compared with sows weaning older piglets (4.26 vs. 11.02 kg weight loss, respectively). These data show that greater levels of SID Lys to target 65 g/d in lactation can improve wean weight for later weaning sows.

106 Evaluation of a Novel Wet/Dry Feeder in Finishing Pigs

Abstract Approximately 1,200 pigs (DNA 241×600, Columbus, NE) at approximately 20 kg were randomly allocated into sixty pens (20 pigs/pen) within 3 treatments to evaluate different feeder styles (conventional dry feeder (Dry), PigEasy (PE) wet/dry (PigEasy, Templeton, IA), or Crystal Springs(CS) wet/dry (Crystal Springs, Brandt, SD). Diets for the study were standard, commercial, mash diets that met the growth requirements for the pigs (NRC, 2012). Pigs were allowed 1 week of acclimation to the respective feeder style before the initiation of the study. Pigs were weighed at the beginning of the trial and at each phase change (approximately every 3 to 4 weeks) until market. Feed disappearance was recorded for each phase for the calculation of average daily gain (ADG), average daily feed intake (ADFI), and feed conversion (G:F). Carcass information was collected by treatment to assess carcass metrics. Data were analyzed by pen, with the fixed effect of feeder type, and using repeated measures (SAS, Cary, NC) for the evaluation of ADG, ADFI, GF. The use of either wet/dry feeder compared with a dry feeder resulted in improved ADFI and body weight and a reduced G:F over time (P &amp;lt; 0.02). At the time of market, pigs on wet/dry feeders were approximately 9 kg heavier compared with a standard dry feeder (121.05, 130.64 and 129.28 kg, respectively; P &amp;lt; 0.01). From d0 until time of first market, both wet/dry feeders had significant differences in ADG, ADFI, and GF compared with the dry feeder (Table 1). The use of a wet/dry feeder resulted in significantly higher backfat (1.54, 1.78 and 1.77 cm, respectively; P &amp;lt; 0.01) compared with the dry feeder. The use of a wet/dry feeder compared with a dry feeder resulted in improved average daily feed intake and daily gain, but reduced G:F and carcass merit compared with the dry feeder. There were no significant differences in performance between the 2 different wet/dry feeders.

162 Investigating Strategies to Manage Feed Supply Chain Disruptions on Grow-Finish Pigs

Abstract In the likelihood of a foreign animal disease outbreak, the U.S. pork industry may face supply chain disruptions, including those to feed delivery. Therefore, our objective was to evaluate feeding strategies to prolonged feed availability in group housed finishing pigs and assess impacts on pig performance. 1,407 mixed sex pigs (92±11 kg BW) were blocked by initial average BW to pens and assigned to 1 of 5 treatments (n =12 pens/treatment, 22 pigs/pen) over a 21-d test period. Treatments were fed for 14 d (P1) and thereafter all pens returned to ad libitum access to a standard commercial diet for 7 d (P2). Treatments included: 1) Pens fed ad libitum (CON); 2) Pens fed at 1.45x ME maintenance requirement daily (1.45x); 3) Pens fed 2x ME maintenance requirement daily (2x); 4) Tightened feeders to lowest setting, fed ad libitum (Closed); and 5) Whole corn kernels, fed ad libitum (Corn). The P1 and P2 BW and feed disappearance were recorded to calculate ADG, ADFI, and G:F. Data were analyzed with pen as the experimental unit and least squares means values reported by treatment. Compared with CON, 1.45x, 2x, Closed and Corn treatments significantly reduced P1 ADG (1.09 vs 0.02, 0.34, 0.72, 0.41 kg/d, respectively), ADFI (3.21 vs. 1.42, 1.90, 2.49, 2.40 kg/d, respectively) and G:F (P &amp;lt; 0.05). During P2, ADG and G:F were both increased (P &amp;lt; 0.05) compared with CON across all treatments. However, ADFI increased only from the CON in the 2x, Closed and Corn diets (P &amp;lt; 0.05). Overall (d 0-21), all strategies attenuated BW, ADG and ADFI (P &amp;lt; 0.0001) compared with CON. However, G:F was only reduced (P &amp;lt; 0.01) in 1.45x and Corn, but not 2x and Closed (P &amp;gt; 0.05) from the CON. In conclusion, implementing management strategies to conserve feed maintained marginal pig growth.

76 Awardee Talk: Maternal Immune Activation Impacts Offspring Immune Function but not Muscle

Abstract Gestational health challenges may influence growth performance and immunity of offspring pigs during postnatal life. In particular, porcine reproductive and respiratory syndrome virus (PRRSV) is endemic in the U.S. herd, but its effects on surviving piglets are largely unknown. Further, dietary supplementation with soy isoflavones lessened the severity of PRRSV infections in weaning and growing pigs. Therefore, the goals of this study were to determine the impact of maternal PRRSV infection on offspring muscle and immune development and the potential of isoflavones to mitigate those effects. Thirteen first parity gilts were randomly allotted to 1 of 3 treatments: fed a diet devoid of isoflavones and not infected (CON), fed the control diet and infected with PRRSV (POS), and fed the control diet supplemented with 1,500-ppm soy isoflavones and infected with PRRSV (ISF). Isoflavone supplementation reduced (P = 0.04) viral load in dams 21d after infection, but did not alter (P &amp;gt; 0.05) feed disappearance and rectal temperature. Piglet mortality was increased (P = 0.04) by PRRSV infection in dams, and surviving piglets were infected with PRRSV throughout the study. Interestingly, muscle and organ weights were not different (P &amp;gt; 0.05) among treatments at postnatal d (PND) 3 with the exception of relative liver weight which was increased (P = 0.04) in POS compared with CON, with ISF being intermediate. Infected litters were lighter (P = 0.02) at PND 21, likely due to postnatal infection. Interestingly, at PND 21 relative liver weight was increased (P &amp;lt; 0.01) in ISF compared with CON and POS. Muscle fiber number and size did not differ between treatments (P ≥ 0.39). Piglets born to infected dams had slower responses during innate immune stimulation (P &amp;lt; 0.01) and also had shifts in T cell populations compared with CON pigs (P ≤ 0.02), indicating an inadequate vaccine response. Overall, maternal infection altered offspring immune responses but not muscle fiber development. Isoflavone supplementation did not mitigate these effects.

257 Effect of Drinker Design on Growth and Water Disappearance of Nursery Pigs

Abstract Changes in genetic potential and management practices may have altered the water requirements of nursery and other classes of pigs. However, there are few recent estimates of the water intake of nursery pigs or effects of factors such as drinker design on intake levels. The objective of this study was to evaluate the effect of two Drinker Design treatments (Nipple vs. Cup) on the water disappearance of nursery pigs (weaning to 6 wk post-weaning; 6.4 ± 1.07 to 22.0 ± 3.39 kg live body weight). A RCBD was used with a total of 336 pigs, housed in 16 pens of 21 pigs in 2 rooms (8 pens/room). Pens had fully slatted concrete floors; floor space was 0.32 m2/pig; there was 1 feeder and 1 drinker per pen. Pigs were fed corn-soybean based diets (meal form) formulated to meet or exceed nutrient requirements (NRC, 2012). Pigs and feeders were weighed at the start and end of the study. Water disappearance was measured using water-flow meters fitted to the pipeline supplying the drinker in each pen. Data were analyzed using the PROC MIXED procedure of SAS; models accounted for the fixed effect of Drinker Design and random effect of block. Drinker Design did not affect (P &amp;gt; 0.05) growth performance (Table 1). However, average daily water disappearance was 19.1% greater (P ≤ 0.05) for Nipple vs. Cup drinkers. Consequently, water:feed disappearance ratio was 15.8% greater (P ≤ 0.05) for the Nipple than the Cup treatment. In conclusion, these results suggest that water disappearance from nipple drinkers was greater than for cup drinkers. The lack of an effect of Drinker Design on pig growth performance suggests that this treatment difference was most likely due to greater water wastage for nipple drinkers rather than any effect on water intake per se.

102 Reduced Caloric Intake Increases the Incidence Rate of Gastric Ulcers in Growing Pigs

Abstract Our objective was to evaluate effects of a disease feed intake pattern on gastric ulcerations. Eighty mixed sex pigs (27.9 ± 1.45 kg BW) were allotted to individual pens and 2 treatments using a complete randomized design. All pigs were fed a 450 µm ground corn-soybean meal diet. Period 1 (d 0-28), all pigs were fed ad libitum. In period 2 (d 29-42), 40 pigs were fed daily based on their individual body weight (averaging 1.45x maintenance) to mimic a disease feed intake (RF) profile. The remaining pigs stayed on ad libitum feed (Ad). Pigs were weighed at d 0, 28 and 42, and feed disappearance measured to calculate ADG, ADFI and G:F within period. At d 42, all pigs were euthanized, stomach pH recorded, and stomach ulcerations scored (0-3 scale, with 0 being normal). Performance, pH and ulceration frequency data were analyzed with pig as the experimental unit and the fixed effect of feeding level. Performance was not different in period 1 (P &amp;lt; 0.05). Compared with the Ad, RF pigs had lower ADG (1.10 vs 0.24 kg/d, P &amp;lt; 0.0001), ADFI (2.15 vs 0.85 kg/d, P &amp;lt; 0.0001) and G:F (0.51 vs 0.28, P &amp;lt; 0.0001) in period 2. Stomach pH was greater in the RF compared with the Ad pigs (P &amp;lt; 0.001). A greater percentage of Ad pig stomachs scored normal to mild on pars oesophagea ulcerations (85 vs 62%), while a greater percentage of RF pigs had a maximum score compared with the Ad (38 vs 15%, respectively). RF pigs had a higher frequency of severe stomach body ulcerations (score 3) compared with the Ad (20.5 vs 15.0%, respectively). These data suggest that a disease feed intake pattern exacerbates the incidence of gastric ulcerations in grower pigs fed a fine micron ground corn.

243 Assessment of Modified Corn Protein as a Protein and Energy Source for Nursery Pigs

Abstract Our objective was to evaluate modified corn protein (MCP) as a protein and energy source in nursery pig diets. A total of 198 weaned pigs (6.25 ± 0.95 kg BW) were assigned across 18 pens (11 pigs/pen) and 2 dietary treatments using a complete randomized design. Pigs were fed in 3 phases consisting of 7, 14, and 21 d respectively. In phases 1 and 2, diets included: 1) Control or 2) 10% MCP, while all pigs were on a common phase 3 diet. Diets were formulated to be iso-caloric with SID Lys at 1.45, 1.40 and 1.35% for phases 1, 2 and 3 respectively. Pigs were weighed and feed disappearance measured to calculate ADG, ADFI and G:F within phase and overall. At the end of phase 2, fecal samples were collected for determination of apparent total tract digestibility coefficients (ATTD) for dry matter, energy and nitrogen. Pen was considered the experimental unit and all data were analyzed using the mixed procedure of SAS with treatment as a fixed effect. In phases 1 and 2, ADG, ADFI and G:F did not differ between Control and MCP treatments (P &amp;gt; 0.05). Similarly, performance did not differ between treatments in phase 3 (P &amp;gt; 0.05). Overall, end BW (25.7 vs. 25.3 kg), ADG (0.42 vs. 0.44 kg/d), ADFI (0.58 and 0.61 kg/d) and G:F (0.71 vs. 0.70) did not differ (P &amp;gt; 0.05) between the Control and MCP treatments, respectively. However, compared with the Control, phase 2 ATTD coefficients for dry matter (80.6 vs. 78.2%), nitrogen (77.5 vs. 75.2%) and gross energy (79.7 vs. 76.9%) were significantly reduced in the MCP treatment (P &amp;lt; 0.05). In conclusion, MCP provided equal nursery pig performance when used as an alternative protein and energy source in diet formulations despite lower ATTD.

PSV-12 Evaluation of Iron Source and Level on Nursery Pig Performance and Blood Hemoglobin Concentrations

Abstract The objective of this study was to evaluate effects of dietary iron (Fe) source and concentration on nursery pig performance and blood hemoglobin concentrations. A total of 960 newly weaned, mixed sex pigs (5.7 ± 0.40 kg BW) were allotted to 4 dietary treatments using a complete randomized design (24 pens/treatment, 10 pigs/pen). All pigs were fed a 3-phase corn-soybean meal-based diet. The 4 diets were: 1) 100 ppm Fe from iron sulfate; 2) 100 ppm Fe from an iron-amino acid complex (Fe-AA; ProPath Fe 150), 3) 50 ppm Fe from Fe-AA and 4) 25 ppm Fe from Fe-AA. Pigs were weighed on day 0, 7, 21 and 42, and feed disappearance measured to calculate ADG, ADFI and G:F within phase and overall. Blood hemoglobin was assessed on d 0, 21 and 35. Pen was considered the experimental unit and all data were analyzed using the mixed procedure of SAS with treatment as a fixed effect. Iron treatment did not alter pig performance (ADG, ADFI and G:F) in phase 1, 2 or 3 (P &amp;gt; 0.05). Overall, ADG was similar between treatments (0.46, 0.45, 0.45 and 0.44 kg/d, respectively, P &amp;gt; 0.05). Similarly, overall ADFI was similar between treatments (0.61, 0.60, 0.58 and 0.62 kg/d, respectively, P = 0.31). Overall 42-day G:F did not differ between treatments (P &amp;gt; 0.05). Blood hemoglobin concentrations (g/dL) showed a quadratic response over day post-weaning (P &amp;lt; 0.001); however, no treatment or treatment by day interaction were reported (P &amp;gt; 0.05). Altogether, these data demonstrate that feeding 25-100 ppm of Fe-AA provided similar performance to 100 ppm Fe from an inorganic source. Additionally, pigs did not have altered hemoglobin levels or become Fe deficient when diets were supplemented with Fe-AA at levels below NRC requirement.

101 Evaluation of Vitamin D on Performance and Bone Mineral Density in Finishing Pigs

Abstract The objective of this study was to evaluate the vitamin D3 (vitD) and 25-hydroxy vitamin D (25-OHD) requirements for finisher pig performance and bone density. Seventy-two pigs (62 ± 11.1 kg BW) were allotted to 36 pens (n = 2 pigs/pen) and across 4 dietary treatments (n = 9 pens/trt) for 51 d. Corn-soybean meal mash diet treatments were: 1) Diet containing 75 IU/kg vitD; 2) Diet containing 150 IU/kg vitD (NRC requirement); 3) Diet containing 750 IU/kg vitD; and 4) As 1 plus 0.0125% 25-OHD to achieve total diet equivalent of 750 IU/kg vitD. Pigs were weighed and feed disappearance recorded at the start and end of the study to calculate ADG, ADFI and G:F. Serum 25-OHD concentrations were determined on d 42. On d 51, one pig per pen was euthanized and bone mineral density determined on the rib, tibia and fibula. Data were analyzed as a complete randomized design with pen as the experimental unit. Overall, ADG did not differ between treatments 1 through 4 (1.26, 1.31, 1.34, 1.27 kg/d, respectively (P &amp;gt; 0.05). Further, ADFI did not differ between treatments (P &amp;gt; 0.05). However, G:F tended to increase as dietary vitD concentrations increased (0.34, 0.36, 0.37 and 0.35, respectively, P = 0.068). Rib, fibula and tibia bone mineral density did not differ between treatments (P &amp;gt; 0.05). Serum 25-OHD concentrations were 9.9, 11.9, 23.3 and 36.6 ng/mL for treatments 1-4, respectively (P &amp;lt; 0.001). In conclusion, vitamin D3 deficiency was not achieved with treatment 1 in finishing and all treatments had equal pig performance and bone mineral density. Further, 0.0125% 25-OHD provided equal performance and bone density to 750 IU/kg of vitamin D3.

97 Effects of Increasing Levels of Hybrid Rye on Growth Performance of 45 to 125 kg Pigs

Abstract A total of 2,400 barrows and gilts (FAST x PIC 800, initially 44.9 kg) were used in an 89-d study to determine the effect on growth performance of increasing inclusion of hybrid rye (KWS Serafino) in a commercial grow- finish setting. Pigs were randomly allotted to 1 of 4 dietary treatments with 30 pigs per pen and 20 replications per treatment. Diets were fed over 5 phases (44.9 to 56.0, 56.0 to 69.0, 69.0 to 87.9, 87.9 to 107.5, and 107.5 to 111.6 kg respectively). Dietary treatments were corn-soybean meal-based replacing either 0, 40, 70 or 100% of the corn with hybrid rye. Diets were formulated to meet or exceed 2012 NRC requirements for all nutrients. Pigs were weighed and feed disappearance measured to calculate ADG, ADFI, and G:F at each phase change. Pigs were marketed across 3 marketing events (d 68 to 89), with an equal number of pigs removed from each pen per event. Data were analyzed using the GLIMMIX procedure of SAS, with block as a random effect and pre-planned linear and quadratic contrast statements for increasing inclusion of rye. Overall (d 0 to 89), increased inclusion of hybrid rye from 0 to 100% decreased (linear, P &amp;lt; 0.001) average market BW, ADG and ADFI. There was no difference (P &amp;gt; 0.10) in G:F with increased hybrid rye inclusion, indicating energy value of hybrid rye used in formulation was correct. In summary, while there was no change in G:F, reduction in ADFI and ADG suggests there is a palatability or anti-nutritional factor affecting pig growth performance.