SAS PROC Research Articles

264 Effects of increasing available phosphorus for 6 to 16 kg pigs fed diets containing phytase

Abstract An experiment was conducted to determine the effects of increasing available phosphorus (aP) levels on growth performance of nursery pigs under commercial conditions. A total of 2,340 pigs [PIC 337 × 1050, initial body weight (BW) = 6.0 kg], placed in pens with 35 or 36 pigs, were used in a 39-d trial. Treatments were arranged in a dose titration with six levels of aP and 11 replicates per treatment. The aP levels were 0.33, 0.39, 0.46, 0.52, 0.59, and 0.65%. Two basal diets with the least and greatest aP levels were manufactured in meal form and blended at the farm to create the intermediate levels. Phytase [Allzyme Spectrum Swine (Alltech, Nicholasville, KY)] was included in the experimental diets at superdose levels with an estimated 0.15% aP release. Calcium levels were adjusted in each diet to maintain a constant 1.20 Ca:P. The experimental diets were fed from d 0 to 21 and a common corn-soybean meal-based diet with adequate aP level was fed from d 21 to 39. Data were analyzed with the MIXED procedure in SAS in a randomized complete block design with pen serving as the experimental unit and initial BW as the blocking factor. From d 0 to 21, pigs fed increasing levels of aP had improved (quadratic, P ≤ 0.024) average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency [gain to feed ratio (G:F); Table 1]. For ADG and G:F, the quadratic polynomial resulted in the best fit predicting 100% of maximum response at 0.50 and 0.52% aP for ADG and G:F, respectively. Similar improvements (quadratic, P ≤ 0.049) were also observed in the overall period (d 0 to 39). From d 21 to 39, while pigs were fed a common diet, there was no evidence (P > 0.05) for differences in growth performance. There was no evidence (P > 0.05) for differences in mortality rate. However, there was a quadratic response (P = 0.008) in removal rate, with declining rates up to 0.59% aP. In summary, growth performance of 6 to 16 kg pigs was maximized with 0.50 to 0.52% aP with further improvements in removal rate observed with greater aP levels.

56 Metabolic status of respiratory disease challenged beef steers altered by intranasal Zn and vitamin A treatments

Abstract Bovine respiratory disease (BRD) is a major cause of morbidity and mortality in the cattle industry. Increasing the ability of a calf to respond to disease is of interest due to the loss of production during disease. Zinc and vitamin A (VA) are key micronutrients involved in many immunologic processes such as cell signaling and mucosal immunity. Angus crossbred steers [n = 48; body weight (BW) = 333 ± 4.2 kg] were utilized in this 14-d BRD challenge investigating intranasal (IN) treatments of Zn and VA. Steers were split into two groups (n = 24) with identical disease challenge and sample collection schedules. Before disease challenge, steers were housed at the Iowa State University Beef Nutrition farm (BNF). Steers were weighed on d -2 and -1 of viral challenge and trucked for 6 h before delivery to the Iowa State University Animal Resource Station. On d 0, steers were challenged with an aerosol inoculation with 104 TCID50 BRSV followed by 5x108 CFU of Mannheimia haemolytica on d 5. On d 4, steers received IN treatments of Zn (ZN; ZnO nanoparticles), VA (VA), Zn and VA (VA+ZN), or control with no IN treatment (CON). For trace mineral and VA analysis, liver biopsies were collected on d -9 and 20 and plasma collected on d 0, 4 (trace mineral only), 5, 7 and 14. Steers were tested for viral shedding on d 0, 4, 5, 7, 10 and 14. RNA was isolated from bronchioalveolar lavage (BAL) cells (d 0 and 7) for gene expression related to inflammation, VA and trace mineral metabolism. Statistical analysis was completed using the GLIMMIX and MIXED procedures in SAS 9.4. Throughout the study, viral shedding was not affected by intranasal treatment (P ≥ 0.59). There were no group × TRT × day effects for plasma trace minerals (Cu, Zn, Fe) or VA concentrations (P ≥ 0.18). Intranasal VA prevented a decrease in plasma VA on d 5, after which all treatments were similar (P < 0.01). There were no TRT × day effects for plasma Zn and Cu (P ≥ 0.50). Post challenge, liver VA was increased in VA treated steers compared with steers not treated with VA (P = 0.04). Liver Mn tended to be increased post challenge in IN ZN treated steers (P = 0.08). IN Zn treated steers tended to have lesser expression of IL-10 in BAL cells on d 7 post infection (P = 0.07). Local IN supplementation of Zn and VA can have systemic and local affects on respiratory disease challenged steers and may support increased response to disease.

52 Alleviating antinutritional effects of high soybean meal diets for nursery pigs through multienzyme and acidifier supplementation

Abstract This study evaluated the effect of multienzyme and acidifier supplementation in high soybean meal (SBM) diets on performance and allergenic response in nursery pigs. A total of 240 weaned pigs, 5.9 ± 0.8 kg body weight (BW), were allotted to 5 dietary treatments with 8 replicates in a randomized complete block design. Dietary treatments were low SBM diet (17% in phase 1 and 20% in phase 2), standard SBM diet (22% in phase 1 and 25% in phase 2), high SBM diet (30% in phase 1 and 35% in phase 2), high SBM diet with multienzyme supplementation (100 ppm of phytase, 500 ppm of carbohydrase, 250 ppm of protease, and 25 ppm of keratinase), and high SBM diet with multienzyme and acidifier (0.5%) supplementation. The enzyme combination was selected based on an in-vitro digestion experiment evaluating the degradation rate for antinutritional factors present in SBM. Diets were provided in a 3-phase feeding program: phase 1 (wk 1), phase 2 (wk 2 and 3), and phase 3 (wk 4 to 6); common corn-SBM based diet. Growth performance was measured at the end of each phase along with blood collection for serum IGF-1, IgA, and IgE analyses. One pig per pen was euthanized to collect intestinal tissue for histomorphology and ileal digesta for sIgA analysis. Data were analyzed using MIXED procedure of SAS and fecal score data was analyzed using FREQ procedure of SAS. Pigs fed high SBM diets with multienzyme or with multienzyme and acidifier tended to have a greater (P = 0.08) average daily gain compared with pigs fed High-SBM diet during phase 2 by 12.5%. Pigs fed high SBM diets with multienzyme and acidifier supplementation had greater (P < 0.05) average daily feed intake compared with pigs fed high SBM diet in phase 2. During phase 1 and 2, pigs fed high SBM diets supplemented with multienzyme or multienzyme plus acidifier had less incidence of soft and watery feces (χ2 < 0.05) than those fed high SBM diet. Dietary treatment did not affect serum concentrations of T4, IGF-1, IgA, and IgE. Pigs fed high SBM diet with multienzyme and acidifier supplementation had less (P < 0.05) concentration of sIgA in the ileal digesta on d 14 compared with high SBM diet (24.2 vs 33.8 mg/mL) but similar to low SBM diet (22.7 mg/mL). Pigs fed high SBM diet with multienzyme and acidifier supplementation had greater (P < 0.05) jejunal villus height to crypt depth ratio on d 7 compared with low SBM by 12%. In conclusion, supplementation with multienzyme or multienzyme and acidifier in high SBM diets could reduce the negative impact of high SBM inclusion in nursery pig diets by improving growth performance, promoting intestinal health, and reducing allergenic response in nursery pigs.

114 Effects of greater levels of soy protein and methionine on periparturient health of sows

Abstract Sow prolificacy in the U.S. continues to trend greater, as does sow mortality. Replacement of soy protein (SBM) in sow diets with corn and purified amino acids (AA), may impact the health of highly prolific sows. In 2015, Denmark increased recommendations for SID methionine (MET) to SID lysine (LYS), MET:LYS to 32%, NRC (2012) recommend 27%. The primary objective of this research was to evaluate SBM and MET at greater levels for their effects on markers of health in the peripartum and lactation periods. A total of 38 parity 1 to 3 females (PIC 1050) were utilized with a starting body weight (BW) of 223.4kg ± 13.0 SD. On d 85 of gestation, sows were allocated by BW and parity to one of four treatments: 1 - 30% SBM (30% of diet), 36% MET:LYS; 2 - 15% SBM, 36% MET:LYS; 3 - 30% SBM, 27% MET:LYS; 4 - 15% SBM, 27% MET:LYS. Sows were fed dietary treatments 28 d pre-farrow, according to BW, and ad libitum throughout lactation. Body condition by caliper (BCS), BW, and backfat (BF) were measured on d 0, 21, 2 d post-farrow, and weaning. Sows were assigned a farrowing ease score of 1 to 4 (1-easy to 4-difficult) based on duration, restless activity, savaging, and assistance required. Continuous glucose monitors (CGM) were placed on a subset of sows (n = 12) on d 113 of gestation through 3 d post-farrow. Data were analyzed using the GLM procedure in SAS with sow serving as the experimental unit. A planned t-test was performed on CGM glucose data. Two sows were removed during lactation. The combined effect of 30% SBM and 36% MET:LYS produced an average lactation BW loss of 0.3 kg, while the 15% SBM and 27% MET:LYS treatment, diets similar to NRC, lost an average of 18.1kg. Sows fed the 30% SBM diets had less lactation BW loss than 15% SBM (Table 1; P < 0.10). Sows fed 36% MET:LYS lost less BW than those fed 27% MET:LYS (P < 0.05). The 36% MET:LYS group also lost less backfat during lactation and had lower pre- and post-farrow body temperatures than 27% MET:LYS (P < 0.01 and P < 0.05, respectively). While no differences in blood glucose were observed, in sows with CGM, greater levels of SBM decreased interstitial glucose concentrations (P = 0.055). In conclusion, greater inclusion of SBM and increasing the MET:LYS ratio in sow diets may improve periparturient changes in body condition and health outcomes.

PS-1 An evaluation of sodium salicylate in the periparturient management of the sow

Abstract Mortality continues to trend higher in highly prolific sows in the U.S., with the periparturient period being the time of greatest loss (Eckberg, 2021). Sodium salicylate (NaSal) is a nonsteroidal anti-inflammatory drug (NSAID) similar to aspirin, which is used to manage pre-eclampsia-related pregnancy complications in humans (Roberge et al. 2017). The objectives of this experiment were: 1) Collect farrowing data for scoring periparturient health; and 2) Evaluate the impact of NaSal on periparturient health and inflammation. A total of 47 parity 1 and 2 females (PIC 1050) were utilized with a starting body weight (BW) of 214.3kg ± 14.7 SD. Sows were blocked by BW on d 105 gestation and parity and randomly assigned to one of two treatment groups. The treatments were: control (CON) n = 23; or treatment (TRT) n = 24. TRT consisted of NaSal (Oral-Pro, Aurora Pharmaceutical, Northfield, MN) administered via water 3 d pre-farrow to 5 d post-farrow, with a target dose of 50 mg NaSal/kg BW. At d 106 of gestation and weaning, BW, back fat (BF), and body condition by caliper (BCS) were measured. Sows were assigned a farrowing ease score of 1-4 (1 - easy to 4 - extremely difficult) based on duration, restless activity, savaging, and assistance required. Data were analyzed using the GLM procedure in SAS, with sow serving as the experimental unit and LSMeans testing for differences among means. Average farrowing duration for both groups was 335.5 min ± 144.2 SD. Farrowing ease score for all sows was assessed as a mean of 2.28 with 47% scored as difficult (Score 3 to 4). Treatment improved farrowing ease score (TRT avg: 1.9; CON avg 2.7; P < 0.01) and reduced savaging severity and frequency (TRT: 5 sows, 1 severe; CON: 8 sows, 7 severe; P < 0.05). TRT sows (24/24) successfully weaned litters compared with CON sows (20/23). All sows assigned a 1 or 2 score (25/25) weaned litters compared with sows assigned 3 or 4 (19/22). In conclusion, farrowing difficulty contributes to the need for greater care of highly prolific sows. Supplementation of NaSal during the periparturient period may improve farrowing ease and health outcomes.

PSIII-15 Effect of dietary fatty acids composition on growth performance, fecal consistency, and plasma fatty acid profile of weaned pigs

Abstract Dietary lipids are an important source of energy and fatty acids (FA), which have critical roles in mucosal immune responses, epithelial barrier functions, and overall intestinal development. Therefore, including fat in nursery pig diets can be used as a nutritional strategy to optimize pig growth performance and intestinal health after weaning. This study evaluated the effects of two different dietary fatty acid compositions derived from conventional soybean oil (CSO) and/or high oleic soybean oil (HOSO) supplementation on growth performance, fecal consistency, and plasma FA profile of weaned pigs. A total of 208 weaned pigs (body weights = 4.96 ± 0.8 kg) were used in a randomized complete block design and allotted to 16 pens of 13 pigs each. Experimental diets met NRC (2012) requirements and were provided in a 3-phase nursery feeding program: Phase 1 (d 0-d7), Phase 2 (d 8-d21), and Phase 3 (d 22-d42). Pens were assigned to one of two dietary treatments consisting of two dietary FA compositions derived from the supplementation of 3% of either CSO (20% Oleic acid; 50% Linoleic acid; 6% Linolenic acid) or HOSO (44% Oleic acid; 30% Linoleic acid; 3% Linolenic acid). Feed disappearance and body weight were measured at d 0, 21, and 42. Pen fecal score was assigned daily from d 0 to 21 and then 3 times per week until d 42. Blood samples were collected on d 21 (2 pigs/pen) for plasma FA profile analysis. Performance data were analyzed using T-TEST and fecal score using PROC FREQ procedures of SAS. From d 0 to 21, pigs fed CSO supplemented diets had a greater (P ≤ 0.05) body weight (8.6 vs. 7.4 kg) and daily gain (0.17 vs. 0.12 kg). In addition, daily feed intake and feed efficiency tended to be 23% and 16% greater in CSO-fed pigs, respectively. From d 21 to d 42, there were no differences between dietary treatments for growth performance. Overall nursery period, pigs fed CSO had greater (P ≤ 0.1) daily gain than HOSO pigs (0.34 vs. 0.30 kg). Pigs fed CSO had a greater (P ≤ 0.05) plasma concentration of palmitic, linoleic, and linolenic FA while pigs fed HOSO had a greater (P ≤ 0.05) plasma concentration of palmitoleic and oleic FA. There were no differences in fecal scores in wk 1 and 2. However, pigs fed CSO had less incidence of soft and watery feces (χ2 < 0.1) in wk 3 to 6. In conclusion, a greater dietary content of linoleic and linolenic FA promoted pig growth performance and reduced incidence of diarrhea after weaning compared with greater content of oleic FA.

61 Effects of botanical composition on grazing system management, forage quality, forage availability, and ewe performance

Abstract The objective was to compare the effects of two forage mixtures utilized in a rotational grazing system on ewe performance, forage quality, and forage availability. Dorset-Suffolk crossbred ewes [n = 48; body weight (BW) = 187 ± 20 kg] were stratified by BW, body condition score (BCS), and age, then allotted to six groups. Groups were randomly assigned to one of two treatments: forage mixture 1 (FM1; 47% orchard grass, 30% white clover, 14% brome grass, and 9% ryegrass) and forage mixture 2 (FM2; 44% ryegrass, 33% white clover, and 23% red clover). There were 18 paddocks (30.5 m x 22 m) for each treatment, each group was rotated between one of six paddocks; the rotation of each group was determined by the reduction of forage height to approximately 10 cm. Ewe BW and BCS were collected on d 0, 14, and 28. Forage heights were measured using meter sticks upon the groups entering and exiting each paddock. Forage heights were used to calculate forage availability, and the difference between pre-grazing and post-grazing forage availability was assumed to be forage disappearance. Five pre-grazing forage samples from each paddock were clipped at 10 cm using the forage square (0.0625 m²) to determine fiber content. Data were analyzed using the GLM procedure of SAS 9.4. No effects on ewe BW or BCS were observed (P = 0.4134) between treatments. Ewes grazing FM2 spent more time grazing each paddock (P < 0.01) compared with ewes grazing FM1. Pre-grazing forage ground cover (P < 0.01) was greater in FM2 compared with FM1; however, grazed forage mass disappearance was not different (P = 0.44) between treatments. The NDF and ADF values were greater for FM1 than FM2 (P < 0.01 and P = 0.02, respectively) indicating that more forage is needed to meet ewe energy requirements. Results suggest that neither forage mixture had a significant impact on ewe BW or BCS; however, ewes grazing FM2 maintained themselves on a smaller land area during growing season, making it a more feasible option for rotational grazing management.

88 Ruminal degradation profiles of dry matter, organic matter, and crude protein of finishing diets with different levels of inclusion of dried distiller’s grains plus solubles and soybean meal

Abstract The objective of this study was to estimate the ruminal degradation profile of dry matter (DM), organic matter (OM), and crude protein (CP) in concentrate-based diets with different levels of inclusion of dried distiller’s grains plus solubles (DDGS) and soybean meal (SBM). Red Angus steers [n = 4; body weight (BW) = 360 ± 9 kg] with ruminal, duodenal, and ileal cannulas, were used in a 4 × 4 latin square. Diets (TMR) consisted of dry-rolled corn (70%), hay (10%), liquid supplement (5%), and test ingredients (15%). Treatments were (DM basis): 1) 15.0% DDGS (CON); SBM in replacement of 50% of DDGS (SBM50); SBM in replacement of 75% of DDGS (SBM75), and SBM in replacement of 100% of DDGS (SBM100). Each period lasted 18-d, consisting of a 7-d diet adaptation followed by an 11-d collection period. An in situ ruminal incubation of each TMR was performed from d 8 to 11 of each period. Ingredients were weighed separately, maintaining their proportion in the TMR. Air-dried TMR sample (6 g, 2 mm grind) was ruminally incubated in a nylon bag (Ankom, 10 × 20 cm) using the same steer from the in vivo study. Samples were incubated for 0, 2, 4, 8, 16, 24, 48, and 72 h. The number of bags varied as a function of the incubation time to guarantee enough residual samples after incubation, where more bags per sample were incubated for the longer incubation times relative to the shorter incubation times (72 and 48 h, n = 5; 24 h, n = 4; 16 h, n = 3; 8 h and 4 h, n = 2; 2 h and 0 h, n = 1). DM, OM, and CP degradation were estimated by using the following model: Yt = a + b × (1 − e(−kd × t)), The NLIN procedure of SAS 9.4 was used and restricted and full models were compared by a likelihood ratio test. Rumen degradable protein (RDP) of each TMR was calculated as follows: RDP = a + b + [kd/(kd + kp)], where kp was 0.05 h−1). There were no differences (P ≥ 0.47) on the fractions a, b, and kd, or RDP (55%) between treatments for DM, OM, and CP. According to our analysis, approximately 13 h of incubation is necessary to accurately estimate the RDP content of the TMR. The NASEM (2016) adopts 35 and 75% of RDP for DDGS and SBM, respectively, based on fixed incubation time of 16 h. Most studies have evaluated degradation profiles of individual feed and not TMR; however, animals are fed complete diets, made up by feedstuff that vary in physical characteristics, nutrient composition, and consequently RDP. In this study, the similar degradation profiles between diets suggest that RDP of complete diets differs from that of individually assayed ingredients.

PSIV-A-5 Effect of roughage inclusion in limit-fed cow rations on behavior, cow hygiene, and manure scores

Abstract The objective was to determine the effects of roughage inclusion in isocaloric total mixed rations (TMR) fed to drylot housed cow-calf pairs on behavior, manure score, and hygiene score. Spring-born Simmental x Angus cows (n = 72) and their calves were stratified by calf age, sex, and body weight (BW) and assigned to 12 pens with 6 pairs to pen. Pens were randomly assigned to one of two treatments: moderate roughage inclusion (40%) TMR targeting DMI of 1.7% of BW (LimitTMR) or high roughage inclusion (60%) TMR targeting DMI of 2.1% of BW (BulkyTMR). Concrete bunks (4.7 m; 0.8 m/cow). Cow-calf pairs were housed in concrete dry lots with open-front buildings. Buildings were bedded with straw once a week. Cow and calf behavior (standing, lying, at bunk, and eating bedding) was observed hourly from 1 h before feeding until 6 h post-feeding. Behavior assessments were done on 2 consecutive days (before new bedding and after new bedding) each week for 5 wk. Hygiene and manure scoring was conducted on d 40 and 75 by 2 trained evaluators. Hygiene was scored on a 1-4 scale; 1 – no manure, 4 confluent plaque of manure. Cow hygiene was evaluated on the lower leg, udder, and upper leg and flank. Manure from each pen was scored on a 1-5 scale; 1 – very liquid consistency, 5 – firm fecal balls. Data were analyzed using the MIXED procedure of SAS 9.4. On day prior to new bedding, there was a treatment × time interaction (P < 0.01) for cows at bunk. More cows on BulkyTMR were at the bunk at h 2, 3, 4, and 5 post-feeding. On day after new bedding, there was also a treatment × time interaction (P < 0.01) for cows at bunk. More cows on LimitTMR were at the bunk before feeding; however, more cows on BulkyTMR were at bunk at h 2 and 3 post-feeding. On both evaluation days there was a treatment × time interaction (P ≤ 0.05) for calves at bunk. More calves on BulkyTMR were at the bunk at h 1 and 2 post-feeding. Cows fed the LimitTMR had dirtier (P ≤ 0.02) lower leg (1.5 vs 1.2) and upper leg/flank (1.4 vs 1.1) hygiene scores on d 40 than cows fed the BulkyTMR; however, there were no treatment differences (P ≥ 0.31) on d 75. There were no treatment differences (P ≥ 0.26) for manure scores on d 40 or d 75. In conclusion, a bulkier TMR with more roughage inclusion resulted in more time at the bunk for cows and calves and cleaner hygiene scores for cows, but roughage inclusion did not affect manure scores.

129 Evaluating effects of myostatin loss-of-function mutation on piglets for potential causes of early mortality

Abstract Pigs with an engineered myostatin loss-of-function mutation in exon 3 (-1T) experience perinatal mortality of unknown cause. From 36 litters resulting from matings of sows and boars both heterozygous for the mutation, 240 total piglets were born but only 14% (5/35) of piglets with myostatin loss-of-function mutation survived or were viable beyond postnatal d 3. Thus, the objective was to evaluate the effects of this myostatin loss-of-function mutation on piglet organ and muscle development and blood parameters to determine potential causes of this excess mortality. Blood was collected for complete blood count and then piglets (n = 50) were euthanized at postnatal d 3. Piglets were dissected and longissimus muscle, semitendinosus muscle, heart, liver, lungs, kidneys, pancreas, spleen, stomach, small intestine, large intestine, testicles or female reproductive tract, and tongue were weighed. Front girth, back girth, and snout to rump were measured. Loin samples were used to genotype piglets into one of three groups: wild type (WT; unmutated myostatin, n = 13), heterozygous (HET, n = 21) and myostatin mutant (MKO, n = 10). Data were analyzed as a two-way ANOVA using the MIXED procedure of SAS to determine the effect of sex, genotype, and their interaction. Body weight (P = 0.67) and front girth (P = 0.13) were not different between genotypes, but back girth was reduced (P = 0.04) in MKO by 2.3 cm compared with WT and by 2.1 cm compared with HET piglets. MKO piglets had lighter (P ≤ 0.03) hearts, livers, kidneys, pancreases, spleens, stomachs, and small intestine compared with HET and WT piglets, on both an absolute basis and as a percentage of body weight. In general, compared with other other genotypes, MKO organs were 5 to 19% lighter. Surprisingly, muscle weights, both longissimus and semitendinosus muscles, were not different (P ≥ 0.15) between genotypes, either on an absolute basis or as a percentage of body weight. White blood cell count was not different; however, neutrophil count was increased in MKO compared with other genotypes. These data suggest that underdeveloped or undersized organs in MKO piglets may compromise their survivability. Additionally, increased neutrophil counts may be indicative of a stress response in MKO piglets.

PSIV-A-3 Effect of fiber and stimbiotic on growth performance and the gut microbiome in pigs challenged with F18 enterotoxigenic Escherichia coli (ETEC)

Abstract Dietary fiber has been shown to promote a healthy gut microbiota, while stimbiotics enhance fermentable substances and boost the expansion of the commensal microbiome, improving host health by alleviating deleterious effects of proinflammatory responses. The intended purpose of this study was to gain an understanding of the effectiveness of dietary fiber sources and stimbiotic on the sustainability of F18 enterotoxigenic Escherichia coli (ETEC) challenge. A total of 216 piglets were blocked (n = 8) by weaning body weight (BW) and randomly assigned to 1 of 4 dietary treatments, including corn-SBM based control diet (CC), high fiber diet (HF: 5.0, 3.8. 2.5% sugar beet pulp and 4.0, 3.0 and 2.0% soy hulls for phases 1, 2, and 3, respectively), CC plus 0.01% stimbiotic (CS: Signis, ABVISTA Marlborough, UK), and HF plus 0.01% stimbiotic (FS). Pigs were fed a four-phase feeding regimen: phase 1 (d 0-9), phase 2 (d 9-16), phase 3 (d 16-22), phase 4 (d 22-41). Dietary fiber and stimbiotic were provided from weaning (d 0) to d 22, and then a common diet was fed from d 22 to the end of the trial. On d 5 postweaning, all pigs were orally inoculated with 10 mL of F18 ETEC (108 CFU/mL). One median BW pig from each pen was selected at weaning for fecal sampling. Before the challenge, the same pigs were sampled on d 5 and again on d 8 and d12. Samples were used to quantify the E. Coli using 3M Petrifilm (3M Food Safety, St. Paul, MN) and virulence genes of the isolate were qualified using multiplex PCR. Colony-forming-count was log-transformed. All data normality was verified using Univariate procedure and analyzed using Mixed procedure of SAS (Cary, NC). Pigs fed both CS and HF increased average daily gain (ADG) in phase 2 and phase 1-3 compared with pigs fed CC diets, while adding stimbiotic had no additional benefit to HF (Fiber×Stimbotic P = 0.03 and 0.06, respectively). This response led to heavier BW in pigs fed CS at the end of phase 3 compared with pigs fed CC with HF and FS as intermediate (Fiber×Stimbotic P = 0.06, respectively). Overall, average daily feed intake (ADFI) was greater in pigs fed CS than pigs fed FS while no difference was found between CC and CF (Fiber×Stimbotic P = 0.02). Dietary fiber did not impact gain to feed ratio (G:F); however, G:F was improved in stimbiotic fed pigs in phase 2 (Stimbiotic P = 0.01). Total coliform count was reduced from d 2 to d 7 (day; P < 0.01), but neither fiber nor stimbiotic altered the coliform count. Results of this study demonstrated that both high fiber and stimbiotic help restore ADG when pigs were challenged with ETEC. Additionally, stimbiotic also benefited feed efficiency and resulted in the heaviest BW.

84 Evaluating the effects of hind gut acidosis in sheep on rumen fermentation ex vivo

Abstract The objective was to determine the effect of hindgut acidosis in sheep on rumen fermentation ex vivo. Eleven ruminally and cecally cannulated ewes [body weight (BW) = 49 ± 4 kg] were assigned to one of two treatments: a constant infusion of deionized water (CON; 26 mL/kg BW per 24 h) or starch solution (STA; 3 g wheat starch/kg BW per 24 h) in the cecum to induce hindgut acidosis. Rumen fluid was collected from each ewe on the d before and four d after the start of cecal infusion for an ex vivo fermentation. There were four flasks for each ewe with two flasks per substrate. The two substrates were forage-based (FB; 40% grass hay pellet, 35% whole shell corn, 15% dried distiller’s grain, and 10% alfalfa cubes) and concentrate-based (CB; 75% whole shell corn, 15% dried distiller’s grain, and 10% alfalfa cubes). Flasks contained 2.5 grams of substrate and 150 mL of inoculum (2:1 ratio of McDougall’s buffer and rumen fluid). Four sealed ANKOM F57 bags were filled with 0.25g DM of substrate and placed into flasks to determine in vitro dry matter disappearance (IVDMD). The flasks were incubated at 39°C for 24 h, with sample aliquots collected at h 0, 8, and 24 to determine pH, volatile fatty acids (VFA), and ammonia. Data were analyzed using the MIXED procedure of SAS 9.4. For all response variables, values from the run before cecal infusion initiation were included in the model as a covariate. Ammonia, pH, and VFA were analyzed with the effects of treatment, time, and their interaction. For the CB substrate, there was no effect (P = 0.90) of cecal infusion on ammonia concentration; however, there was a time effect (P = 0.01) with h 24 having a greater ammonia concentration than h 8. For the FB substrate, there was a tendency for STA to have lesser (P = 0.10) ammonia than CON. There was no effect (P ≥ 0.78) of cecal infusion treatment on pH for both substrates; however, there was a time effect (P = 0.01) with pH decreasing over time. In both substrates, there were no effects (P ≥ 0.23) of cecal infusion treatment on IVDMD, VFA concentration, acetate, or propionate molar concentration. However, butyrate molar concentration tended to be less (P = 0.07) for STA ewes for the CB substrate. No treatment differences were observed in butyrate for the FB substrate (P = 0.35). Results indicate that induced hindgut acidosis in sheep did not affect rumen fermentation ex vivo.

100 Evaluating the effect of liver copper concentration on vaccine response in lightweight dairy-beef steers

Abstract Dairy-beef crossbred calves often face greater copper (Cu) exposure than native beef calves, which may impact their response to vaccines. To investigate this, 28 weaned dairy-beef steers (90.25 ± 1.28 kg; ~8 wk old) were enrolled in a study to determine the effect of Cu status on the antibody response to vaccine. Steers were stratified by body weight (BW) and assigned to one of two dietary treatments: low Cu (no supplemental Cu) and high Cu (supplementing 20 mg Cu/kg DM). Steers were housed in pens of six to eight animals for 82 d before d 0 of the vaccination period to create distinct liver Cu groupings. Seven days before initial vaccine dose, liver biopsies were collected, and steers were grouped into low (n = 13) and high (n = 15) Cu treatments. Liver Cu for low Cu averaged 291 ± 24 mg/kg DM (range 240 to 376 mg/kg DM) and for high Cu averaged 665 ± 23 mg Cu/kg liver DM (range 519 to 893 mg/kg DM). All calves were vaccinated on d 0 and boostered 21 d later with Bovilis Vista 5 SQ (Merck Animal Health, Rahway, NJ) and an ovalbumin vaccine. Blood and BW were collected on these days and again on d 49 to end the study. Serum antibody titers for BRSV, BHV1, BVDV1, and BVDV2 were analyzed by the Iowa State University Veterinary Diagnostic Laboratory (Ames, IA). Response to ovalbumin vaccination was determined using an ELISA. Plasma Cu concentrations were determined on d 0, 21, and 49 via ICP-OES. Ovalbumin antibodies were determined by calculating the ratio of each sample to a positive control. Titers, ovalbumin response, and plasma Cu data from d 0, 21, and 49 were analyzed using the Mixed procedure of SAS 9.4 (Cary, NC) with the fixed effect of Cu treatment and day as repeated. Plasma Cu decreased across days (P = 0.0008). Given both treatments had adequate liver Cu, it is unsurprising plasma Cu did not differ by treatment (P = 0.2; 1.02 and 1.07 mg Cu/L for low and high Cu, respectively). Antibodies for BRSV, BHV1, and BVDV2 increased across days (P < 0.0001), but there were no differences by treatment (P ≥ 0.12). Ovalbumin antibodies were affected by treatment by day (P = 0.04), where high Cu had greater response to ovalbumin than low Cu on d 21, but by d 49 ovalbumin antibodies were similar between Cu treatments. These results suggest excessive liver Cu concentration may not affect response to vaccination in dairy-beef steers; however, more research is needed to determine the effects of increased liver Cu concentration on oxidative stress and immune system function.

203 The relationship between potentiated zinc oxide and monovalent copper in a dietary administration for weanling piglets

Abstract The aim of this study was to evaluate different dietary level of Zinc (Zn) and Copper (Cu) supplementation according to European and non-European levels on the health and performance of pigs 14 d after weaning. A total of 120 piglets [initial body weight = 7.14 ± 0.92 kg] were divided into 4 experimental treatments: positive control (PC, 2,500 ppm of Zn, ZnO) and 3 treatments in which Zn and Cu were added through potentiated ZnO and Cu2O according to different European and non-European levels of inclusion: EU (120 ppm of Zn; 140 ppm of Cu), non-EU+ (300 ppm of Zn; 200 ppm of Cu) and non-EU- (300 ppm of Zn; 140 ppm of Cu). Growth performance, serum Zn and Cu concentrations, fecal score, blood biomarkers of intestinal integrity, and fecal microbial composition were examined and analyzed using GLM and MIXED procedures of SAS. Fecal samples at 14 d were collected and the V3–V4 hypervariable regions of the bacterial 16S gene were sequenced in one Illumina MiSeq run. Body weight (BW), average daily gain (ADG), average daily feed intake (ADFI), feed conversion ratio (FCR) and (feed efficiency (FE) were not affected by the experimental treatments. The fecal score suggests that during the first 14d, the consistency of the feces tended (P < 0.10) to be less in the three treatment groups while in PC, the greatest concentration of Zn favored a better fecal consistency. The initial serum Zn and Cu concentrations were similar for all dietary treatment groups. After 14 d, serum Zn concentration was significantly greater in PC (15.71 ± 6.25 µg/L, P < 0.05). No differences were highlighted in serum Zn concentration among the other 3 treatment groups. Serum Cu concentrations revealed statistically significant results (P < 0.05) on 14 d after weaning in EU, non-EU+ and non-EU- groups, showing greater concentrations of Cu (17.65 ± 5.49 µmol/L, 17.73± 3.46 µmol/L 18.33 ± 4.13 µmol/L, respectively) compared with PC (11.87 ± 3.60 µmol/L). These results suggested that the EU level of inclusion of both potentiated Zn and monovalent Cu is enough to reach the same Cu and Zn plasma concentrations of non-EU treatments. Plasma DAO was negatively (P < 0.05) affected in non-EU-. Firmicutes and Bacteroidetes were the most abundant phyla in fecal microbiome. Non-EU- contributed to a significant decrease in biodiversity in fecal microbiota as depicted with Shannon for diversity and Simpson for evenness indexes (P < 0.05). In fecal samples, the presence of genera linked to a greater disruption of the gut barrier (Escherichia-Shigella) was depicted in non-EU- group, indicating significant modifications of the microbial community. These results suggest the need for a balanced supplementation of Cu and Zn through more bioavailable sources. The use of potentiated ZnO and Cu2O according to European levels could represent a valid strategy to enhance weanling piglets gut health and to reduce the environmental impact.

162 Effect of molasses-based liquid supplement vs. corn-based dry supplement on beef cattle feedlot performance, carcass characteristics, and intestinal length

Abstract Molasses-based liquid supplements contain sugars that can be fermented into butyrate, the primary source of energy for gastrointestinal (GIT) epithelial cells and may improve gut health and enhance beef cattle performance. The aim of this study was to examine how a molasses-based liquid supplement, in contrast to a dry-based supplement, impacts the performance, carcass characteristics, and intestinal length of beef cattle. Crossbred steers [n = 60; body weight (BW) = 381.7 ± 1.3 kg] were divided into 10 pens (5 pens per treatment; 6 steers per pen) and were assigned to one of two treatment groups: dry, which consisted of a 10% ground corn-based dry supplement, or liquid, which included a 10% liquid molasses-based supplement. All the steers were fed a high-forage diet (56%) and were transitioned to a high-grain diet (7%) on d 1 of the experiment. The animals were on feed for an average of 122 d and had ad libitum access to feed and water. Steers were weighed every 21 to 28 d, and feed intake, average daily gain (ADG), and gain to feed ratio (G:F) were assessed both overall and for two distinct periods: the initial period (IP) from d 0 to 69, and the subsequent or second period (SP) from d 70 until slaughter. Intestinal length was measured at the time of slaughter. Data analysis was performed using the GLIMMIX procedure of SAS. Body weight and ADG did not differ between treatments in either period, or overall (P ≥ 0.41). However, it is noteworthy that feed intake was greater for steers that received the dry supplement during both periods as well as across the entire study (P ≤ 0.04). In terms of G:F, steers provided with the liquid supplement demonstrated a tendency for improved efficiency in the second period (P = 0.09) and an overall greater efficiency (P = 0.04) compared with those receiving the dry supplement. Intestinal length exhibited no difference for both the small and large intestine (P ≥ 0.57). For carcass data parameters no differences were observed for hot carcass weight, dressing %, or %KPH (P ≥ 0.24). Fat depth tended to be greater (P = 0.06), and yield grade (P = 0.01) and marbling score (P = 0.03) were greater for the steers fed the dry supplement. Rib-eye area was greater (P = 0.03) for the liquid supplement group. Therefore, these findings suggest feeding a liquid based supplement to steers on a 93% concentrate diet decreases intake, maintains BW, and improves feed efficiency and carcass leanness compared with steers fed a dry supplement. However, the improvement in efficiency as a result of feeding a liquid based supplement was not caused by an increase in absorptive capacity through increased intestinal length.

PSIV-A-6 Effects of a yeast cell wall additive on the growth performance and fecal Eimeria load of finishing lambs

Abstract Yeast-based additives have been shown to alter the rumen environment and exhibit immunomodulatory properties that can lead to enhancements in health status and subsequent performance. The objectives of this study were to evaluate the impacts of supplementing a yeast cell wall additive (Safwallâ, Phileo by Lesaffre, Milwaukee, WI) on finishing lamb growth performance and fecal Eimeria load. A total of 44 Polypay lambs were used in a 35-dexperiment at the Kansas State University Sheep and Meat Goat Center. On d 0, a fresh fecal sample was collected from each lamb and submitted to the Kansas State University Veterinary Diagnostic Lab to determine a baseline Eimeria count via quantitative fecal float. Lambs were then randomly assigned to either a control diet or diet supplemented with 1.5 g Safwallâ. Diets were fed for 35-d and contained no coccidiostat. Lambs had ad libitum access to both feed and water for the duration of the experiment. A basal lamb finisher diet was manufactured as a control diet and Safwallâ was hand-mixed into rations daily to make the treatment diet. Lambs and feeders were individually weighed weekly to track dry matter intake (DMI) and changes in body weight (BW). Data were analyzed using the GLIMMIX procedure of SAS (v.9.4, SAS Inst., Cary, NC) with an alpha set at (P < 0.05). From d 0 to 7 there was no evidence of a difference (P = 0.19) in DMI between treatment groups; however, during the second week of the study (d 7 to 14) lambs fed the control diet had significantly greater (P = 0.02) DMI compared with those fed a diet supplemented with yeast cell wall (Table 1). There was no evidence of differences in DMI between treatments for the remainder of the study (P > 0.05). Likewise, BW did not differ significantly (P > 0.05) between treatments on d 0 or by d 35. There was no evidence that fecal Eimeria load differed significantly (P > 0.05) on d 0 or 21; however, on d 35, lambs fed the control diet had a decreased Eimeria load compared with those fed a diet with yeast cell wall, but neither group had biologically relevant levels of Eimeria present in the feces. In summary, feeding a diet containing a yeast cell wall additive did not alter finishing lamb growth performance. While lambs fed the control diet had reduced fecal Eimeria at the end of the study, there was a reduction in this variable across both treatments. Further research should be conducted with younger animals with a known Eimeria challenge.

298 Impact of ruminal acidosis on cattle energy metabolism

Abstract The objective of this study was to determine the impact of a bout of ruminal acidosis on energy metabolism of cattle unadapted to a high concentrate diet. Eleven ruminally cannulated steers [body weight (BW) = 352 kg ± 27] were blocked into 3 groups based on initial BW. Before the start of the experiment, animals were consuming a forage-based diet as well as adapted to the headbox style respiration chambers. Additionally, before the experiment, gas emission data were collected over a 24-h period when cattle received an ad libitum forage-based diet for use as a covariate in the statistical analysis. For the experiment, steers were moved into headboxes at the conclusion of a 24-h fast and subsequently received 1 of 2 treatment diets: control (CON), forage-based diet or acidosis (AC), concentrate-based diet. Steers remained in the headboxes for 48 h. Gas concentrations from each headbox were collected hourly and analyzed with an infrared photoacoustic gas analyzer. Ruminal pH, fecal pH, volatile fatty acids, and lactate were also measured during the acidosis challenge. Data were analyzed with the MIXED procedure of SAS 9.4. A treatment × day effect (P = 0.03) was observed for dry matter intake with intake being similar for both CON and AC steers on d 1 but AC steers consuming 2.02 kg less on d 2. Treatment affected ruminal pH (P < 0.01) as CON steers had a greater ruminal pH than AC steers. Greater total volatile fatty acids (P < 0.01) were observed for steers on AC treatment compared with CON. A treatment × time interaction (P < 0.01) was observed for ruminal lactate concentration with AC steers having greater concentrations from h 16 to 36. Fecal pH was affected by a treatment × time interaction (P = 0.05) as AC steers had lower fecal pH from h 24 to h 32. Over the 48-h observation period, there was a treatment × time interaction (P = 0.04) for carbon dioxide production as AC steers produced less CO2 after h 24. No treatment × time interaction was detected for oxygen consumption. However, there was a time effect (P < 0.01). Respiratory quotient was not affected by treatment, day, or their interaction (P ≥ 0.19). Heat production tended (P = 0.06) to be different between treatments, with AC having less heat production than CON. Thus, the effects of ruminal acidosis on gas emissions and energetics may be more transient during the time course of an acidotic bout or have a longer duration even after ruminal pH has recovered.

PSVI-4 Effects of ruminal acidosis on rumen fermentation of steers adapted to a high concentrate diet

Abstract The objective was to characterize the effects of ruminal acidosis on rumen fermentation of steers adapted to a high concentrate diet. Cattle entering the feedlot undergo a transition period where the amount of concentrates in the diet is gradually increased to mitigate the risks of ruminal acidosis. Despite a dietary adaptation, rumen acidosis still affects feedlot cattle later in the finishing phase. Ruminally cannulated steers [n = 11; body weight (BW) = 795 kg ± 54) were blocked into 2 groups based on initial BW. Before the start of the study, cattle had been consuming a finishing diet (60% dry rolled corn, 15% modified distiller’s grains, 15% corn silage, and 10% ground corn based supplement) for more than 150 d. Steers were randomly assigned to 1 of 2 treatments: control (CON) or acidosis (ACD). For the experiment, steers were fasted for 24 h and at the conclusion received the same finishing diet. Steers on ACD steers were also ruminally dosed 0.05% BW of wheat starch on h 0 and h 12 to induce acidosis. Rumen fluid was collected every 4 h for 48 h to analyze ruminal pH, ammonia, volatile fatty acids (VFA), and lactate. Fecal grab samples were collected every 8 h for 48 h to determine fecal pH. Data were analyzed with the MIXED procedure of SAS 9.4 with the effects of treatment, time, and their interaction. A treatment × hour (P < 0.01) effect was observed for ruminal pH with the ACD steers having a lower pH than CON from h 12 to 32. Fecal pH was not affected by treatment, time, or their interaction (P ≥ 0.12). Steers fed ACD had greater total VFA concentration than CON (P < 0.01). A treatment × hour interaction (P < 0.01) was observed for acetate molar proportion with CON having greater percentage acetate at h 24 through 32. Additionally, there was a treatment × hour interaction (P < 0.01) for propionate molar proportion with ACD steers having greater propionate at h 28 and 32, and then at h 40 and 44. Butyrate was not affected (P ≥ 0.58) by treatment × hour or treatment. Acetate to propionate ratio (A:P) was affected by treatment × hour (P < 0.01) with CON steers having greater A:P after h 28. Rumen ammonia and lactate concentrations did not differ (P ≥ 0.25) by treatment or the interaction with h. In steers adapted to a high concentrate diet, acidosis only altered ruminal fermentation in regards to ruminal pH and VFA concentrations.

169 The impact of corn-based fiber on intestinal morphology and disaccharidase activity in growing pigs

Abstract Dietary changes can modify gastrointestinal architecture and function; thus, our experimental objective was to evaluate how different insoluble corn-based fiber sources (CBF) impact intestinal morphology and brush-border disaccharidases. Two replicates of 28 gilts [26.7 ± 2.5 kg body weight (BW); PIC800 x Camborough; n = 56], were randomly assigned to one of 7 semi-synthetic diets, including a control (CTL) diet with a formulated total dietary fiber (TDF) value of < 1% and 6 diets with a CBF replacing 30% of the corn starch in CTL: dehulled degermed corn (DHDG; TDF = 1.09%), ground corn (COR; TDF = 3.24%), high protein dried distillers grains (HP; TDF = 8.79%), dried distiller’s grains (DDGS; TDF = 9.35%), corn gluten meal (CGM; TDF = 9.88%), and corn bran (BRN; TDF = 13.15%). Pigs were individually housed, and limit-fed 2.4 times maintenance. On d 31, pigs were necropsied, and duodenum, jejunum, ileum, cecum, and colon tissue were collected for histological analysis. Data were analyzed as a linear mixed model with treatment as a fixed effect, replicate as a random slope or fixed effect, where appropriate, using the mixed procedure of SAS. In the duodenum, DHDG, COR, and CGM had the least (P = 0.04) levels of maltase production. Duodenal sucrase production was least in BRN and HP, and DHDG had the greatest (P = 0.04). Duodenal villi height was shortest (P < 0.01) in CTL and BRN compared with HP, DDGS, and CGM, which had the tallest (P < 0.01; Table). Similarly, CTL and BRN had the shallowest duodenal crypt depth (P < 0.01) and tended (P = 0.08) to have a lesser duodenal villus:crypt ratio compared with the other treatments. There were no differences (P > 0.10) among treatments for ileal sucrase or lactase production, but maltase production was greatest in CTL, DDGS, and CGM (P = 0.03). Relative to CTL and BRN, gilts fed HP, DDGS, and CGM, had the tallest (P = 0.01) villus height in the ileum. However, neither ileal villi:crypt ratio nor crypt depth differed (P > 0.10). Cecal crypt depth for BRN increased 32% compared with CTL (P < 0.01). Cecal crypt width was narrowest (P < 0.01) in CTL and DHDG and widest in HP, DDGS, CGM, and CB (P < 0.01). Colon crypt width was narrowest (P < 0.01) in CTL and DHDG and widest in DDGS, CGM, and CB (P < 0.01). Collectively, these data demonstrate that different fiber types have a significant impact on intestinal morphology and disaccharidase production in the growing pig.

16 Effects of fiber supplementation during gestation on sow and piglet performance

Abstract Our objective was to determine the effects of fiber supplementation during gestation on sow and piglet performance. A total of 200 PIC Camborough P1+ sows were used. At breeding, sows were balanced by body weight (BW) within parity and randomly allotted to 1 of 2 dietary treatments, which consisted of 1) Control; corn-soybean meal gestation diet; and 2) Fiber; inclusion of soybean hulls in the formulation at a level to yield a dietary crude-fiber content 6%. Females were housed in individual stalls throughout the entire gestation. At d 90 of gestation, serum glucose, fecal dry matter, fecal volatile fat acids (acetate, propionate, butyrate, isovalerate, and valerate), urinary traits (color, turbidity, density, pH, and presence of nitrate or blood), and frequency of stereotypic behavior (sham chewing, teeth grinding, bar biting, and floor licking) was accessed. Perineal scoring was visually evaluated at d 105 and 110 of gestation. Farrowing traits (farrowing length, and number of piglets born alive, stillborn, and mummified fetuses) and piglet vitality (meconium presence, umbilical cord integrity, oxygenation, and heart rate) were individually monitored. Individual piglet BW was obtained within 12 h of birth and after 24 h for colostrum intake, and at weaning. Sow daily lactation feed intake was registered. Data were analyzed using generalized linear mixed models with the Glimmix procedure of SAS with sow serving as the experimental unit. There was no evidence (P > 0.10) for differences in sow BW at d1, d112 of gestation, and at weaning. Sows fed the greater fiber diet showed lower levels of post-prandial glucose (-6%; P < 0.10), darker urine (+33%; P < 0.10) with greater pH (+5%; P < 0.05), and greater levels of fecal butyrate (+62%; P < 0.05) and isovalerate (+15%; P < 0.10) at the end of gestation (d 90). Feces from sows fed the control diet were drier (P < 0.05) at d 90 of gestation. Fiber supplementation reduced the frequency of teeth grinding (-52%; P < 0.10), bar biting (-74%; P < 0.05), and floor licking (-65%; P 0.10) behaviors. There was no evidence for treatment differences (P > 0.10) for perineal scores. Piglet vitality was not affected by the treatments, except for a marginal increase in blood oxygen saturation for piglets from sows fed the greater fiber diet (+1%; P < 0.10). Treatment did not impact (P > 0.10) farrowing duration, number of total piglets born, born alive, stillborn, and mummified, nor average piglet birth weight and colostrum intake. Sows fed diet with fiber supplementation during gestation had a marginal increase in average daily feed intake during lactation (+0.50kg/d; P = 0.08), which resulted in improved piglet BW gain (P < 0.05) and weaning weights (+0.20kg; P < 0.05). In summary, providing increased level of fiber supplementation via soybean hulls to gestating diets did not impact sow reproductive performance. Beneficial effects were observed for welfare lactation feed intake, piglet BW gain and weaning weights.