bluuebunny/crossref_metadata_2025 huggingface dataset:
255 Evaluation of Growth Performance and Bone Mineral Density in Grower Pigs Fed Phosphorus, Calcium, and Vitamin D Deficient Diets
Authors: Smith Leah , Sparks Chris , Gabler Nicholas K
Published: October 2023

The objective of this study was to evaluate the effects of phosphorus, calcium and vitamin D deficient diets on growth performance and bone mineral density (BMD) in grower pigs. In two replicates, a total of 80 mixed sex pigs (26.7 kg BW) were allotted by BW and sex into individual pens across 5 dietary treatments (16 pigs/trt) for 28 days. Diets were: 1) Positive control (PC) diet containing monocalcium phosphate and no phytase, 2) PC diet containing phytase 1,500 FTU of Optiphos 2500, 3) Diet deficient in phosphorus (no monocalcium phosphate or phytase), 4) Calcium deficient diet (as diet 2 with no limestone), and 5) Diet deficient in vitamin D as diet 2 containing no added vitamin D. All diets were formulated to 3,297 kcal/kg ME, 1.15% SID Lys and contain the same AA:Lys ratios. Total Ca was formulated to be 0.76, 0.53, 0.45, 0.20 and 0.53%, with available P at 0.32, 0.32, 0.07, 0.32 and 0.32% respectively, for Treatments 1-5. Vitamin D was formulated to be at 154 IU/kg diet for Treatment 1-4. Pig BW and feed disappearance were recorded at the start and end of the study to calculate ADG, ADFI and G: F. On day 28, serum was collected, and all pigs euthanized to determine whole body bone, foot, rib, femur, and tibia BMD via dual x-ray absorptiometry. Data were analyzed with pen as experimental unit, fixed effect of dietary treatment, sex and their interaction, and initial BW block and repartition as random effects. Diet by sex interactions not observed (P >0.05). Compared with either Treatment 1 and 2, P and Ca deficient diets reduced ADG (0.96, 1.01, 0.80 and 0.91 kg/d, respectively (P < 0.001). The ADFI did not differ across dietary treatments. Vitamin D deficient pigs did not differ from either control treatments. Feed efficiency was different between treatments 1-4 (0.51, 0.53, 0.47 and 0.50, respectively, P < 0.001). Whole body BMD was reduced in the P and Ca deficient diets compared with Treatment 1 and 2 (0.582, 0.678, 0.803 and 0.758 g/cm2, respectively, P < 0.001). Similar results for 10th rib, femur, and tibia bones (P < 0.001). Vitamin D deficient diets reduced whole body and tibia BMD compared with Treatment 1 by 1.5% (P < 0.05). Gilts had greater whole body (0.762 vs. 0.703 g/cm2) and tibia (0.448 vs. 0.408 g/cm2) BMD compared with barrows (P < 0.05). In conclusion, dietary phytase provided similar performance and BMD to that of non-phytase control diet. Feeding P and Ca deficient diets for 28 days reduced pig growth and bone density, with P diets having more severe reductions. Further, while there was a slight reduction in growth there were no detrimental effects on bone mineralization in pigs fed vitamin D deficient diets.
256 Evaluation Calcium and Phosphorus Ratios in the Presence of Phytase on Performance and Whole-Body Bone Mineralization in Growing Pigs
Authors: Smith Leah , Sparks Chris , Gabler Nicholas K
Published: October 2023

The objective of this study was to evaluate the effects of dietary calcium and phosphorus ratios in the presence of super dose phytase on grower pigs growth performance and bone mineral density. In two replicates, a total of 48 mixed sex pigs (26.7 kg BW) were allotted by BW and sex into individual pens across 3 dietary treatments (16 pigs/treatment) for 28 days. All diets contain phytase at 1,500 FTU/kg of complete feed and the three diet treatments were formulated with differing levels of Ca to achieve 0.7, 1.1 and 1.5 total Ca:total P. All diets were formulated to be isocaloric and isonitrogenous and ratios were achieved by vary limestone and sand. Pig BW and feed disappearance were recorded at the start (d 0) and end (d 28) of the study to calculate ADG, ADFI and G:F. On day 28, all pigs were euthanized to determine whole body bone, foot, rib, femur and tibia bone mineral density via dual x-ray absorptiometry. Data were analyzed with pen as the experimental unit, fixed effect of dietary treatment, sex and their interaction, and initial BW block and repartition as random effects. Differences were determined significant at P ≤ 0.05. Pig ADG was increased in the 1.1 verses 0.7 and 1.5 Ca:P diets (1.01, 0.95 and 0.95 kg/d, respectively, P = 0.046). End body weight was not different in the 0.7, 1.12 and 1.5 Ca:P treatments (53.5, 54.8 and 53.1 kg, respectively, P = 0.106). Diet Ca:P ratio did not alter ADFI or G:F. Whole body, tibia and femur bone mineral density was increased by 110% in 1.5 verses 0.7 Ca:P fed pigs, with bone mineral density being intermediated in the 1.1 Ca:P diets. Whole body (0.740, 0.752, 0.797, g/cm2, for 0.7, 1.1 and 1.5 Ca:P respectively, P = 0.033). For 0.7, 1.1 and 1.5 Ca:P femurs, bone mineral density was 0.463, 0.498 and 0.516, respectively, P = 0.034). Dietary treatment did not alter whole foot or 10th rib bone mineral densities (P > 0.05). Sex did not affect pig performance, but gilts had a 9% increase in bone mineral content. In conclusion, formulating dietary Ca:P in the presence of super dosing phytase at 1.1:1 total Ca:P resulted in the best ADG, but a ratio of 1.5:1 had the greatest bone mineral density.
273 Longitudinal Investigation of Nutrient Intervention During Gilts Development on Sow Reproductive Performance and Longevity
Authors: Tsai Tsungcheng Cheng , Sam Bernard Abeiku , Davis Nathan , Grogan Hannah , Bergstrom Jon R , Coble Kyle , Orlando Uislei A , Hough Sara D , Blake Kayla , Dritz Steve , Vier Carine M , Maxwell Charles V
Published: October 2023

The objective of this study was to evaluate the dietary nutrient level and vitamin D source during gilt development on sow reproductive performance and longevity. Three groups of gilts (n = 60 in each group, PIC Camborough) were received at 9 weeks of age (average BW: 21.2 ± 0.67 kg) and assigned to one of four dietary treatments. Treatments comprised two levels of dietary nutrients (Adeq: optimal growing diets that exceed NRC 2012 recommendations or Low: moderate slow growing diet that SID lys and ME levels were gradually reduced by 0.03% and 0 kcal/kg, 0.15% and 146 kcal/kg, and 0.15% and 150 kcal/kg, respectively) and two sources of vitamin D [StD: 1653 IU cholecalciferol/kg or HyD: 500 IU cholecalciferol/kg + 50 mcg calcifediol (ROVIMIX HY-D DSM Nutritional Products North America)] during development phase 1 (22 to 57 kg), 2 (57 to 91 kg), and 3 (91 until breeding). Dietary nutrient level treatment was withdrawn during gestation and lactation stages, while sows remained on their vitamin D treatments through three reproduction cycles. Replacement gilts (n = 12 in each cycle) were handled and treated the same as the initial three groups of gilts and introduced to each group at the end of each cycle. Gilts fed Low diets had decreased ADG (P = 0.01), lighter BW (P < 0.01), increased ADFI (P < 0.01), and poorer feed efficiency during development (P < 0.01) when compared with gilts fed Adeq. Gilts fed Low were lighter (149.8 kg) than the Adeq (153.9 kg) fed gilts. Sows fed Low diets during their development had reduced number of stillborn (P < 0.01), 0.79 more pigs born alive (P = 0.10), and weaned a total of 238 more pigs than Adeq sows (2,127 vs 1,889, P < 0.01). Numerically greater lactation intake allowed sows developed using Low diets to have greater backfat at weaning compared with those developed using Adeq diets (weaning backfat: 13.0 vs 11.9 mm, P = 0.03). Gilts and sows fed HyD had significantly greater born alive litter weight (P = 0.03) due to numerical greater born alive (14.2 vs 13.47, P = 0.14) but average born alive piglet BW (P = 0.86) was not different. Piglets from sows fed HyD_Low diets had greater preweaning mortality compared with piglets from sows fed StD_Low diets because of greater number of pigs born alive observed in HyD_Low sows (1.323.vs.1,143, P = 0.02). Interestingly, a total of 5 sows that were culled due to lameness were all from the first cycle and StD treatment. Moreover, the percentage of sows rebred tended to be greater in sows fed HyD diets (P=0.08). These data indicate that the level of dietary nutrients fed during gilt's development and feeding HyD continuously from gilt development through subsequent reproductive phases, modulated reproductive performance.
280 Effects of a Yeast Feed Additive for Maternal Programming of the Postweaning Pig Microbiome
Authors: Law Kayla , Johnston Lee J , Urriola Pedro E , Loughmiller Joe , Kiros Tadele G G , Gomez Andres
Published: October 2023

The objective of this study was to determine whether feeding live yeast to sows from day 85 of gestation and through lactation influences pig performance and microbiomes in the postweaning period. Three dietary treatments were imposed on mixed-parity sows during late gestation and lactation based on the inclusion level (%) of Actisaf Sc47 in corn/soybean meal-based diets: Control (C, 0%), Low (L, 0.1%), and High (H, 0.5%). Pigs (n = 240; 80/maternal dietary treatment group) were selected randomly at weaning (~19 days old) for further performance data collection throughout the nursery period. A subset of these pigs (n = 180; 60/maternal treatment group) were selected randomly for microbiome sampling through fecal swabs collected on days 4 (T1) and 28 (T2) postweaning. Pigs were housed in pens in a confinement nursery barn according to maternal dietary treatment group (10 pigs/pen; 0.28 m2/pig of floor space; 8 pens/treatment group). Treatment groups were kept separate from each other by maintaining one empty pen between treatment groups to prevent potential microbial cross-contamination. Pigs were balanced by litter, body weight, and sex during nursery allotment. Pigs had ad libitum access to water and a common industry-relevant diet, fed in four phases from weaning through day 42. Pigs were weighed individually at the end of each dietary phase (d4, d14, d28, d42). DNA was extracted from fecal swabs and sequenced on the MiSeq platform, targeting the V4 variable region of the 16S rRNA bacterial gene. Sequence data were analyzed using QIIME2 and DADA2, plus various packages within the R statistical software. Performance data were analyzed using repeated measures and generalized linear mixed models that included maternal treatment as a fixed effect, maternal parity as a random effect, and pen as the experimental unit. Daily weight gain was greater for L pigs (0.47 kg) compared with H pigs (0.42 kg; P < 0.05), while ADFI was increased for L pigs (0.57 kg) compared with both C and H pigs (0.49 and 0.47 kg, respectively; P < 0.05; see Table). No differences in microbiome diversity were observed at either time-point. However, microbiome composition differed based on maternal treatment group at both time-points (T1: PERMANOVA, R2 = 0.02, P=0.001; T2: PERMANOVA, R2 = 0.04, P=0.001). These results indicate that live yeast supplementation in sow diets in late gestation and lactation may have lasting effects on pig performance and microbiome composition in the post-weaning period.
290 Vitamin A and Beta-Carotene Supplementation on Growth Performance, Immune System, and Mammary Gland Development in Finishing Pigs
Authors: Elefson Sarah , Greiner Laura L
Published: October 2023

A total of 224 finishing pigs were randomly assigned to split-sex pens (n = 4 pigs per pen). Each pen was assigned to one of four diets: control (7,656 IU vitamin A/kg), control diet supplemented with vitamin A (4.36 ppm; Rovimix A 1000, DSM, NJ, US), control diet supplemented with beta-carotene (163.28 ppm; Rovimix β-Carotene 10%, DSM, NJ, US), or control supplemented with oxidized beta-carotene (40 ppm; 10% active ingredient, Avivagen, Ottawa, ON, Canada). Pigs and feeder weights were recorded at the start of the study (d 0) and end of each phase (days 21, 42, and 63). A subset of gilts was randomly selected and a blood sample for vitamin A (retinol) analysis was collected on days 0, 18, 39, 60, and 63. The same gilts were vaccinated against Lawsonia intracellularis and porcine circovirus. Antibodies against each vaccination were measured on days 18, 39, and 60. At the end of the study, the subset of gilts was euthanized to obtain a liver sample for vitamin A (retinyl palmitate is converted to retinol for measurement) analysis and a jejunum sample to measure the mRNA abundance of genes involved in vitamin A metabolism (alcohol dehydrogenase class 1, lecithin retinol acyltransferase phosphatidylcholine-retinol O-acyltransferase, retinol binding protein, and beta-carotene oxygenase 1). Mammary tissue from the second and fourth right anterior mammary glands were collected to assess gland development via immunohistochemical staining for T cells, B cells, and macrophages (CD3, CD20, and IBA1, respectively) and DNA extraction. Vaccine antibodies measures, vitamin A analysis, and mammary immunohistochemical staining was completed at Iowa State University Veterinarian Diagnostic Laboratory (Ames, IA). Data were analyzed in SAS 9.4 (Statistical Analysis System, Cary, NC) via GLIMMIX procedure. Pen was the experimental unit and fixed effects were diet and time. Gilts were nested within pen when appropriate to account for more than one gilt per pen. Oxidized beta-carotene supplementation increased (P = 0.02) average daily gain across phases; however, there were no differences (P = 0.18) in the body weight of pigs. There was no effect (P > 0.05) of diet on plasma or hepatic retinol, IgG or IgM concentrations, immune cell presence, or DNA in mammary tissue. Supplemented vitamin A tended (P = 0.05) to increase the expression of retinol binding protein in the jejunum, but other genes were not affected (P > 0.05) by dietary treatments. A diet by time interaction (P = 0.04) was noted for circovirus sample-to-positive ratios and titer levels, where vitamin A supplementation had better vaccine responses at the end of the study. Thus, pigs supplemented with oxidized beta-carotene had an improved average daily gain over vitamin A supplemented pigs, but pigs supplemented with vitamin A appeared to have a more robust immune system.
283 Growth Performance, Carcass Characteristics and Economic Parameters Comparison Between Medicated and Antibiotics Free Programs in Wean-To-Finish Pigs
Authors: Cabrera Rafael A , Cabrera Dolores , Bruder Emily , Gourley Gene
Published: October 2023

The objective of this trial is to contrast the growth performance, carcass characteristics and economic parameters of pigs either raised with no antibiotics, antibiotics or supplemented with natural compounds from weaning to market. Barrows and gilts (1,260 Camborough 42 female x Waldo boars) were randomly assigned to 6 treatments (10 replicates, 21 pigs/pen): Negative Control (NC) with no antibiotics; Positive Control (PC) with antibiotics (600 g/ton of CTC, 35 g/ton of Denegard and 400 g/ton of CTC in phase 1, 2 and 3, respectively); TRT 3 had no medication and was supplemented 500 g/ton in the nursery and 250 g/ton of Oregano Essential Oil in G-F (Ecodiar, Nutrinae LLC, Palo Alto, CA); TRT4 had no medication and was supplemented with 250 g/ton of Oregano and 250 g/ton of Quillaja saponaria (Nuquil, Nutrinae LLC, Palo Alto, CA) in the nursery plus 125 g/ton of Oregano and 125 g/ton of Quillaja saponaria in the G-F period; TRT5 was as TRT3 plus Oregano liquid via water first 14 days in the nursery; and TRT6 was as TRT4 plus Oregano liquid via water first 14 days in the nursery. The PC treatment had no medication in phase 4 nursery diet and the entire grow-finish (G-F) period. Pigs were vaccinated at day 5 and day 21 pre-weaning with 1 mL of PCV and Mycoplasma, at day 62 post-weaning via water with Enterisol Ileitis and Salmonella vaccines and finally at day 63 post-weaning with 2 cc of an autogenous vaccine. Pigs were fed a 50% crumble diet in phase 1 and 2 nursery diets (5 and 12 lb./pig, respectively) and a meal diet in phase 3 and 4 (9.09 kg/pig for each phase). A meal diet was fed for the entire G-F period. Data were analyzed with PROC MIXED of SAS and P < 0.05 was used to identify significant differences among the LS Means. Results showed that PC treatment pigs were significantly heavier (P < 0.01) than any other treatments and they also had significantly (P < 0.01) improved FCR when compared with NC, TRT4 and TRT 6 at the end of the nursery period (0 to 42 days). The PC treatment had significantly (P < 0.05) lower feed cost/pig and feed cost/gain when compared with TRT4 and TRT6 during the G-F period (42 to 174 days). PC treatment had improved (P< 0.01) FCR and lower (P< 0.05) feed cost/pig and feed cost/gain when compared with TRT4 and TRT6 from wean-to-finish (0 to 174 days). TRT 5 had overall similar growth, economic and carcass performance as PC treatment from wean-to-finish. Carcass characteristics and carcass gain did not differ among the treatments. In conclusion, it is possible to raise ABF pigs from wean-to-finish when supplementing natural compounds in the feed in nursery and G-F diets and in the water during the nursery period.
295 The Effect of Weaning age and Diet Complexity on Nursery Pig Growth Performance and Weight at Market
Authors: Richert Jacob A , Scaff Taw , Brizgys Lauren A , Ferrel Jon , Schinckel Allan P , Radcliffe John Scott , Richert Brian T
Published: October 2023

Changes in weaning age and diet complexity can impact pig growth post-weaning. Weanling gilts and barrows [n = 432 Topigs Duroc X (US York X Landrace)] from the same farrowing group were utilized for a 30 or 35 day growth trial to compare early (EW) versus late weaning (LW) and high or low levels of specialty proteins in nursery diets. Pigs (n = 216) were EW (18 or 19 d, average Age = 18.4 days, average BW = 5.96 kg) and 216 pigs were LW 5 days later (24, 25 or 26 d, average Age = 24.6 d, average BW = 7.50 kg). At weaning pigs were blocked by weaning age, BW, sex and litter, and randomly allotted to 48 pens with 9 pigs/pen. Pigs at each weaning age were fed a High Complexity (HC) or a Low Complexity (LC) diet. The trial was conducted as a 2X2 factorial design: 1) EW+HC; 2) EW+LC; 3) LW+HC; 4) LW+LC. Pigs and feeders were weighed on d 0, 7, 14, 21, 28, and 35 for EW, and on d 0, 7, 14, 21, 28, and 30 for LW. The LW pigs had improved ADG and ADFI from days 0-7, 7-14, 14-21, and the final week of the nursery (P < 0.05). There were no differences in ADG and ADFI from days 21-28 (P > 0.05) between weaning ages. G:F decreased for LW pigs from days 21-28 (P < 0.01) compared with EW pigs; however, for the overall nursery trial LW pigs had increased G:F (P = 0.01). The LW pigs had increased overall nursery ADG vs EW pigs (452.5 g/d vs 400 g/d; P < 0.01). End of nursery BW was greater for LW vs EW pigs (21.70 kg vs 20.74 kg; P = 0.001). When comparing pigs of similar BW at weaning, LW pigs were lighter at end of nursery (20.13 kg vs. 21.66 kg; P < 0.01) but were more feed efficient (P < 0.01) than EW pigs. There was a BW block by weaning age interaction, EW heavy pigs had less ADG compared with LW heavy pigs; however, when comparing light weight pigs, the EW light pigs had improved ADG compared with LW light weight pigs (P = 0.017). The EW pigs were lighter at market (approximately day 146 of age) compared with LW pigs (120.78 vs 124.16 kg; P = 0.014). An interaction between weaning age, nursery diet, and sex (P < 0.07) was observed for market weight, EW barrows fed LC diets were lighter at market (120.77 kg) than EW barrows fed HC diets (126.54 kg). Whereas for LW barrows fed LC had greater market weights (130.04 kg) than LW barrows fed HC diets (127.59 kg). A similar, but non-significant pattern was observed for gilts. Weaning age and feeding pigs the correct diet for their age in the nursery can have a lifelong effect on the pig.
293 The Effect of Creep Feed and Nursery Diet Flavoring on Piglet Lactation and Nursery Performance
Authors: Pounds Kara , Richert Jacob A , Scaff Taw , Brizgys Lauren A , Cecil Mekenzie , Helfrich Caden , Radcliffe John Scott , Schinckel Allan P , Richert Brian T , Asmus Matthew D , Jones Daniel B , Thayer Morgan T
Published: October 2023

Larger litter sizes in swine production systems and potential milk limitations for piglets have given new opportunities to incorporating creep feeding as a management strategy. Sows (n = 51) and their litters were used to test the effects of creep feed and nursery diets on piglet lactation and nursery growth performance. Ten days before weaning, litters were assigned to one of three creep feeding treatments: 1) Control diet: 2) Control+Flavoring (50 ppm Allium XL, Pancosma): 3) No creep feed. Creep feed was delivered twice/day via one bowl creep feeder/litter. Sows and litters (17/treatment) were allotted to equalize parity (average = 2.8), genetics, number of piglets (average = 10.9), and weaning age (average = 19.1). Litter weights and creep feed intake were recorded on d 0, 4, and 10 (weaning). Post-weaning pigs were allotted to Control or Flavoring (50 ppm Allium XL) diets in a 3x2 factorial arrangement. During nursery there were 10 pens/treatment with 7 or 8 pigs/pen, blocked by initial BW within creep treatment. Nursery treatments were fed in phase 1 (1.13 kg/pig) and 2 (2.27 kg/pig) diets followed by common phase 3 (6.8 kg/pig) and 4 (ad lib to d 35) diets. Weekly pig BW and feed intake were used to calculate nursery pen ADG, ADFI, and G:F. Data were analyzed using GLM procedure of SAS 9.4. Creep feeding treatment during lactation did not affect litter or piglet BW gain pre-weaning. Flavoring did not affect total creep feed intake (control = 114 g/pig vs. flavoring = 110 g/pig). Providing creep feed during lactation increased ADFI on days 2, 3, and 4 post-weaning (P < 0.013). Pigs fed either creep feed increased week 1 nursery ADFI (8.8%; P< 0.02), numerically increased ADG (5.2%), and greater d ay7 BW (P = 0.055). Week 3 ADG (P < 0.05) and ADFI (P < 0.05) were greater for the no creep pigs than pigs fed the control creep feed, flavored creep feed pigs were intermediate. For week 4, ADG, and week 4 and 5 ADFI, pigs previously fed control creep had greater growth performance than pigs previously fed flavored creep with pigs fed no creep being intermediate (P< 0.05). Overall (days 0-35), pigs fed control creep had greater ADG ( P< 0.05) and ADFI (P < 0.05) than flavored creep fed pigs with no creep pigs being intermediate in ADG and greater ADFI than flavored creep fed pigs. Final BW (P < 0.05) was greater for control creep fed pigs than flavored creep fed pigs with no creep pigs being intermediate (23.5 kg, 23.0 kg, 23.3 kg, respectively). Nursery dietary flavoring treatment did not affect post-weaning ADG, ADFI, or G:F at any point during the study (P > 0.12). Lactation creep feeding significantly increases ADFI and ADG during the first week post-weaning, which could improve post-weaning performance and reduce the rate of pigs failing to thrive post-weaning.
296 Short-Term Diurnal Heat Stress Modulation of Growing Gilt and Barrow Growth and Feed Intake
Authors: Due Elizabeth M , Weber Thomas , Gabler Nicholas K
Published: October 2023

During summer months, the increase in temperature and humidity can lead to heat stress conditions that have negative impacts on the growth performance of pigs. The objective of this study was to characterize the effects of diurnal heat stress (dHS) on gilt and barrow growth, day-time and night-time feed intake. Twelve gilts and 12 barrows (46.5 ± 2.47 kg BW) were individually housed in metabolism crates over two experimental periods. For Period 1, all pigs were housed in thermoneutral (TN) conditions (20-21°C and 40-60% humidity). Following the TN period, period 2 consisted of four days of dHS (6 h at 32°C, 18 h at 27°C, 40-60% humidity). The conditions in the dHS period were designed to replicate summer, industry-applicable cyclical heat stress conditions. In each period lasting 4 days, pig BW and feed disappearance were recorded and ADG, ADFI and G:F calculated. Additionally, within each day, 0700 to 1700 h (day-time) and 1700 to 0700 h (night-time) feed intake was recorded. Changes in pig body temperatures (BT) and respiration rates (RR) were measured daily at 0800, 1200 and 1800 h. Pig was considered the experimental unit, and all data were analyzed for the fixed effects of period (TN vs. HS), sex, and period-by-sex interaction. There were no period-by-sex interactions observed for any analyzed variable (P > 0.05). As expected, dHS markedly increased pig 3-day average BT and RR compared with their TN values (P < 0.05). Compared with TN, dHS BT measurements at noon, PM, and overall were on average 1.0°C greater (P < 0.0001). The RR was also increased by 200 to 300% for AM, noon, PM, and overall, for the dHS period as compared with TN (P < 0.001). Within the dHS period, BT was highest at the noon and PM recordings, and RR was highest at the noon recording (P < 0.0001). Pigs tended to have reduced ADFI during dHS compared with TN period (1.54 vs 1.70 kg/d, P = 0.051). During the TN period, pigs consumed 61% (1.03 kg) of daily total feed consumption during day-time and 39% (0.67 kg) in the PM period (P < 0.0001). The opposite effect was found during dHS, in which pigs consumed 33.3% (0.52 kg) of their total daily feed during the peak heat conditions (day-time) and 66.7% (1.02 kg) consumed in the cooler night-time period (P < 0.0001). Compared with barrows, gilts tended to have greater overall ADFI (1.61 vs. 1.48 kg/d; P = 0.079). Within both the TN and dHS period, gilts had a lower average noon BT (P < 0.05), and lower morning RR (P < 0.05). Altogether, three days of dHS increased pig RR and BT, and decreased ADFI. However, day- and night-time feed intake patterns changed compared with the TN period. Diurnal heat stress has similar impacts to both gilts vs. barrows.
303 Interactive Effects of Pelleting and Particle Size Reduction of Corn on Ileal Digestibility of Starch and Amino Acids in Corn-Soybean Meal Diets Fed to Pigs
Authors: Lee Su A , Rodriguez Diego A , Stein Hans H
Published: October 2023

The objective was to determine the interactive effects of particle size reduction and pelleting on the apparent ileal digestibility (AID) of starch and the standardized ileal digestibility (SID) of amino acids (AA) in corn-soybean meal diets fed to pigs. Six corn-soybean meal based diets were arranged in a 3 × 2 factorial with 3 particle sizes of corn (i.e., 700, 500, or 300 μm) and 2 diet forms (i.e., meal or pelleted). An N-free diet was also used and there were, therefore, a total of 7 diets. Pigs were allowed ad libitum access to feed and water. Pigs (n = 7; initial body weight = 59.30 kg; SD = 2.77) that were equipped with a T-cannula in the distal ileum were allotted to the 7 diets using a 7 × 7 Latin square design with 7 periods. Ileal digesta were collected for 2 days after 5 days of adaptation. The statistical model included diet as fixed effect and pig and period as random effects. Contrast coefficients were used to determine effects of diet form, linear effects of particle size, and the interaction. Results indicated that the AID of starch was linearly increased (P = 0.001) with reduced particle size of corn and pelleted diets had greater (P = 0.029) AID of starch than meal diets (Table 1). The SID of Leu, Lys, Met, Phe, Thr, and Val linearly increased with reducing particle size, but the increase was greater in pelleted diets than in meal diets (interaction, P < 0.05). The SID of Arg, His, Ile, and Val also linearly increased (P < 0.05) as the particle size of corn was reduced, and the SID of all indispensable AA except Trp was greater (P < 0.05) in pelleted diets than in meal diets. In conclusion, reducing the particle size of corn from 700 to 300 μm increased the AID of starch and the SID of AA, but the AID of starch and the SID of most indispensable AA was greater in pelleted diets than in meal diets. If there were interactions, the effects of reducing particle size were greater when corn particle size was reduced from 500 to 300 μm in meal diets and from 700 to 500 μm in pelleted diets.
300 Metabolizable Energy and Amino Acid Digestibility by Growing Pigs may be Reduced if Excessive Heat is Applied During Drying of Corn
Authors: de Oliveira Maryane Sespere Faria , Torres-Mendoza Leidy J , Wiltafsky-Martin Markus K , Stein Hans H
Published: October 2023

Two experiments were conducted to test the hypothesis that both drying temperature and drying time affect the standardized ileal digestibility (SID) of amino acids (AA) and metabolizable energy (ME) in corn fed to growing pigs. A single source of corn was divided into 11 batches that were dried using a “drying chamber” at 80ºC for 1.5, 3.0, 24, or 48 h or at 130ºC for 1.5, 3.0, 6.0, 9.0, 12, 24, or 48 h. Exp. 1 was designed to determine the concentrations of ME in the 11 batches of corn. Eleven diets based on each batch of corn were formulated. Growing barrows (n = 88; BW = 20.6 ± 1.2 kg) were allotted to the 11 diets in a randomized complete block design with 8 blocks of 11 pigs. Urine and fecal samples were collected for 4-days after 7-days of adaptation. Contrast statements were used to determine effects of temperature and drying time within temperature. Exp. 2 was designed to determine the SID of AA in the 11 batches of corn. An N-free diet and 11 diets that each contained one of the 11 batches of corn as the sole source of AA were formulated. All diets contained 0.40% chromic oxide as an indigestible marker. Twenty-four growing pigs (22.8 ± 5.1 kg) that had a T-cannula installed in the distal ileum were allotted to a replicated 12 × 4 Youden square with 12 diets and four 7-day periods in each square. Therefore, there were 8 replicate pigs per diet. Ileal digesta were collected on days 6 and 7 of each 7-days period. Data were analyzed as described for Exp. 1. Results indicated that ME (dry matter basis) was greater (P < 0.01) if corn was dried at 130ºC than at 80ºC (Table 1). The ME (dry-matter basis) increased (quadratic, P < 0.04) with drying time at 80ºC, whereas it decreased at 130°C (quadratic, P < 0.05). The SID of AA did not differ between corn dried at 80°C and 130°C, except that the SID of Lys was less (P < 0.05) if corn was dried at 130°C than at 80°C. The SID of most AA decreased (linear or quadratic, P < 0.05) as time of drying increased at 130°C. In conclusion, the SID of AA and ME in corn are not reduced by extending the time of drying at 80°C. However, the digestibility of AA is reduced if corn is dried at 130°C and the longer the time of drying the more the SID of AA is reduced. Values for ME in corn are increased if corn is dried at 130°C rather than 80°C.
82 The Ominous Storm: How to Plan and Execute a Feeding and Management Program in Poor Health Situations
Authors: Kellner Trey A
Published: October 2023

The majority of presentations, podcasts, and panels are based on how to prevent viral and bacterial challenges within sow farm populations. However, this presentation will cover how to plan and execute a feeding and management program when poor health situations are likely and do occur. Most research is conducted on how to maximize pigs weaned per sow per year in ideal conditions; however, how should one feed and manage sows to maximize pigs weaned per sow per year when health is not ideal? What preparation steps must be taken in terms of diet formulation, characterizing body condition, feeding the individual sow, and preparing the sow and gilts immune system and microbiota before a health insult occurs? What if any management action items or formulation strategies are available to employees during and once a health challenge has occurred? How can we maximize the pigs weaned during a health challenge? Last, what should be done if the health challenge is chronic or after a health challenge is finished to return the sow herd to a high level of production? This presentation is not going to have the sole and exact answer to solve each of these critical questions. Still, it will provide multiple tools and strategies to employ before, during, and post a health challenge within a sow farm.
104 Investigation Into the Serum Metabolome and Identification of Biomarkers for Early Detection of Postpartum Dysgalactia Syndrome in Sows
Authors: Studer Jamie M , Kiefer Zoe E , Koester Lucas R , Johnson Erika M , Baumgard Lance H , Schmitz-Esser Stephan , Greiner Laura L , Keating Aileen F , Farkas Attila , Galina Lucina , Vonnahme Kimberly A , Ross Jason W
Published: October 2023

The swine industry is comprised of highly productive and healthy sows capable of weaning large litters for multiple parities. This prolificacy has resulted in greater metabolic demands during lactation due to increased capacity and demand for milk production. Modern sows also have increased genetic merit for leanness which has altered the amount of energy reserves available for mobilization to support the growing demands of lactation. Together, these factors may render modern sows more vulnerable to metabolic disorders such as postpartum dysgalactia syndrome (PDS) or mastitis-metritis-agalactia (MMA). Described as a metabolic and hormonal disturbance, a hallmark of PDS is a reduction (dysgalactia) or cessation (agalactia) in milk production after farrowing. Insufficient milk production by the sow leads to increased piglet mortality, causing substantial economic losses, reducing sow welfare, and resulting in premature removal of sows from the herd. Our prior reports have shown differences in circulating analytes and inflammatory markers between healthy sows and sows affected with PDS following parturition. However, very few differences were observed before clinical signs were evident, rendering these analytes ineffective in early detection of PDS. Therefore, the objective of the current study was to utilize gas-chromatography mass-spectrometry (GC-MS) to further characterize the biological conditions and metabolic pathways contributing to PDS in sows. Through this, we aimed to identify small molecules in circulation with the potential for use as a biomarker to aid in early detection of PDS. To accomplish this, a study was conducted on a commercial sow farm with a history of poor lactation performance. Sows (n = 36) with clinical signs of PDS were matched by parity and day of lactation with healthy control (CON) sows (n = 36) that remained unaffected. Blood samples collected at farrowing (timepoint 1) and at onset of clinical PDS (timepoint 2) were subjected to GC-MS. As expected, piglets from PDS sows had decreased (P < 0.01) average daily gain and greater mortality than piglets from control sows. Following GC-MS analysis, 16 and 41 molecules were identified as significantly different between CON and PDS sows at timepoint 1 and timepoint 2, respectively (P < 0.10). A difference in 2-hydroxybutyric acid, an early marker for insulin resistance and impaired glucose regulation, was observed at timepoint 1. Additional molecules identified as significantly different at timepoint 1 include D-pinitol, D-glucose, inositol (3,6)-bisphosphate, and others. These differentially abundant molecules at timepoint 1 represent potential biomarkers for early detection of PDS.
101 Evaluation of Vaginal Infusion with Ampicillin on Incidence of Pelvic Organ Prolapse in Late Gestation Sows
Authors: Kiefer Zoe E , Johnson Erika M , Studer Jamie M , Moura Cesar A A , Ross Jason W
Published: October 2023

Within the last decade, increased sow mortality resulting from pelvic organ prolapse (POP) has become a growing concern in the swine industry. Despite being widely acknowledged as a prevailing sow welfare and production issue, mitigation strategies are lacking. Previous studies have demonstrated changes in the vaginal microbiome are associated with increased risk for POP during late gestation. Therefore, the vaginal microbiome represents a potential target for prevention strategies. The objective of the current study was to evaluate effects of vaginal infusion using ampicillin on POP incidence. We hypothesized that altering the vaginal microbiome through the use of antibiotics would reduce POP risk during late gestation. Ampicillin was infused into the vagina at two timepoints during late gestation. The first dose (10 mL at 200 mg/mL) was administered approximately three weeks prior to farrowing followed by a second, equivalent dose at approximately three days pre-farrowing. Sows were randomly assigned to treated (TRT; n = 824) and non-treated (CON; n = 739) groups based on gestation pen. Eighty-seven percent of sows in the TRT group received both infusions of ampicillin. At gestation week 15, sows (n = 1076) were evaluated for prolapse risk using a 3-point perineal scoring system. Briefly, a perineal score (PS) of 1 (PS1) presumes little to no risk of prolapse, a PS of 2 (PS2) presumes moderate risk of POP, and a PS of 3 (PS3) presumes high risk of prolapse. From the 1,076 sows assigned a PS, 46.5%, 49.7% and 3.8% of sows were scored PS1, PS2, or PS3, respectively. Ampicillin treatment did not affect PS (P = 0.20) during late gestation, with 45.6%, 51.6% and 2.8% of CON sows and 47.2%, 48.1% and 4.7% of TRT sows scoring a PS1, PS2, or PS3, respectively. Additionally, treatment did not affect POP incidence (P = 0.74), with 4.5% of CON sows and 4.7% of TRT sows subsequently experiencing POP. When evaluating litter characteristics, ampicillin treatment did not affect number of total born, liveborn, or stillborn piglets (P ≥ 0.54). However, an effect of PS was observed on total born and stillborn piglets (P ≤ 0.01), and a tendency to effect number of liveborn piglets (P = 0.06). Sows assigned a PS3 during late gestation had fewer piglets born alive, presumably due to the increased number of stillborn piglets. Additionally, PS3 sows had 1 more total piglet on average within their litters compared with PS1 assigned sows (P = 0.01). In conclusion, vaginal infusion of ampicillin had no effect on PS, POP incidence or litter characteristics, but PS did have an effect on the number of piglets born alive. This project was supported by the National Pork Board and the Foundation for Food and Agriculture Research.
24 Intestinal Function and Integrity in Health and Disease: Current Knowledge in Swine
Authors: Gabler Nicholas K , Burrough Eric R
Published: October 2023

Optimal lean tissue accretion is contingent on the ability of the pig to efficiently establish and maintain host defenses, and to digest and absorb nutrients and water. Epithelial cells in the mucosa of the gastrointestinal tract interconnect with each other by tight junctions, adherens junctions, and desmosomes, forming a complete intestinal barrier. Of the secretory cells in this epithelial barrier, mucus secreting goblet cells and hormone producing enteroendocrine cells can be found interspersed, while Paneth cells lie in the base of the crypts and secrete antimicrobial proteins/peptides into the mucus layer. In the small intestine, enterocytes lining the villi allow for efficient nutrient transport. Maintenance of the epithelial barrier and its function is dependent on intestinal stem cells residing at the crypt base. Two major signaling pathways controlling intestinal stem cell proliferation and differentiation are the β-catenin/Wnt and Notch signaling pathways. Thus, achieving and maintaining optimal nutrient absorptive capacity requires an intricate balance amongst β-catenin/Wnt and Notch signaling pathways, wherein dysregulation of either can result in inefficiency of nutrient absorption. Weaning transition, off-feed events, hypophagia, and enteric and respiratory diseases can all compromise the structural and secretory barrier of the gastrointestinal tract mucosa via changes in tight and adherens junction proteins and mucin production. As a result, these stressors can increase the incidence of gastric ulcers, villous atrophy, and colitis in pigs. Depending on the severity and duration of the mucosal damage, repair and restitution occurs due to increased stem cell proliferation, migration, and repolarization. Thus, efficiency of digestive and absorptive function depends on several factors, including the types of epithelial cells present and their functionality, the rate of cell renewal, and epithelial surface area. This paper will discuss what we know about the regulation and repair of the mucosal epithelium in growing pigs during health, stress, and disease.
160 Effect of Nexpro on Immune Response and Performance of Finishing Steers
Authors: McLaughlin Amy M , Loy Daniel D , McGill Jodi , Hansen Stephanie L
Published: October 2023

This study aimed to determine the effect of NexPro on growth performance, carcass characteristics, and markers of immune function in finishing cattle. Angus-cross steers (n = 210) weighing 465 ± 48 kg were used for this 89-day study. Steers were blocked by BW into four treatments: SBM; a control diet with 11% soybean meal on DM basis; NP9 (9% NexPro), NP12 (12%), and NP15 (15%). NexPro replaced dry-rolled corn in the diet as NP inclusion increased. NexPro treatments each had 9 pens and SBM had 8 pens (6 steers per pen). On day 0, steers were implanted with Component TE-200 (Elanco Animal Health). The BW of all steers and bunk refusals were measured on d -1, 0, 26, 61, 75, and 89 and were used to calculate pen gain, DMI and feed efficiency for each period. One steer per pen was selected for blood collection and muscle biopsies collected on d 26 and 75. From d 61 to 89 steers received 300 mg/d of ractopamine hydrochloride (RAC; Actogain; Zoetis). Fresh blood samples were used for immune cell population determination using flow cytometry. Data were analyzed using the Mixed procedures of SAS with pen as the experimental unit and fixed effects of treatment and block. Performance data were analyzed using d 0 BW as covariate. During the pre-RAC period (d 0 to 61) steers fed the SBM treatment ate more (P < 0.001) than steers fed the NP diets. Steers on the SBM diet had the greatest ADG, with NP12 and NP15 intermediate, and NP9 lowest (P ≤ 0.06), with no treatment differences in G:F (P = 0.26). However, during RAC DMI improved in all NP treatments, and were not different (P = 0.32) from SBM. During the RAC period, ADG tended to be greater (P = 0.09) in NP15 than all other treatments, and G:F was improved (P = 0.01) in NP15 compared with other treatments. Carcass-adjusted BW and ADG, and HCW were less in NP9 (P ≤ 0.02) but similar between SBM, NP12 and NP15. Carcass-adjusted G:F did not differ by treatment (P = 0.50). On d 26, NP12 and NP15 had greater frequencies of live gamma-delta T cells, and on d 75, NP15 had the greatest frequency of these cells (P ≤ 0.016). All NexPro treatments had greater percentages of CD45RO positive B cells on d 75 (P = 0.03) and increased frequency of live total natural killer cells from d 26 to 75 (P = 0.06). The less than expected DMI and greater rumen undegradable protein in NexPro may have caused NP9 to be RDP deficient. However, the greater inclusions of NexPro supported excellent cattle gains, similar or better than SBM.
159 Impact of Constant Inclusion or Decreasing Inclusion of Distillers Grains with High-Quality or low-Quality Roughage on Finishing Cattle Performance
Authors: Lorences Sofia Suarez , Troyer Braden C , Norman Mitch M , MacDonald Jim C , Erickson Galen E
Published: October 2023

Crossbred, calf-fed steers (n = 480; initial body weight = 292 ± 19 kg) were used in a randomized block design finishing experiment with a 2 × 3 arrangement of treatments to evaluate the impact of constant inclusion or decreasing inclusion of modified distillers grains plus solubles (MDGS) with high-quality or low-quality roughage on finishing cattle performance. Dietary treatments included two roughage sources to provide similar neutral detergent fiber (NDF) from forage (6% corn stalks versus 12% corn silage DM basis) in three diets containing 0, 15, or decreasing inclusion of distillers (30, 15, then 0% across the feeding period). A total of 48 (10 steers/pen) pens were used with 8 pens/treatment. There was an interaction (P = 0.04) between roughage source and MDGS inclusion for dry matter intake (DMI). Cattle fed stalks with decreasing inclusions of MDGS (30-0%) had greater DMI than those fed silage as roughage source, but at 0% inclusion of MDGS there was no difference between roughage sources. No other significant interactions were observed, so main effects will be presented. Cattle fed the diet with 0% MDGS inclusion had reduced (P < 0.05) hot carcass weight (HCW), DMI, average daily gain (ADG), and 12th rib fat, and poorer G:F compared with cattle fed diets where MDGS was at 15% inclusion continuously or when MDGS decreased from 30% to 0%. For the treatment where MDGS was decreased from 30% to 0%, performance differed from that of cattle fed 15% distillers continuously. Cattle fed decreasing inclusions of MDGS (30-0%) had less (P < 0.01) DMI, ADG and tended (P = 0.07) to have lighter HCW. But G:F was not (P = 0.25) affected compared with when distillers was fed at 15% continuously. Marbling score was impacted by distillers inclusion (P = 0.03), where cattle fed 15% MDGS had greater (P = 0.01) marbling score than 0% inclusion and tended (P = 0.06) to be greater than cattle fed 30-0% MDGS. Even though there are differences in marbling score across treatments, all three treatments were within the choice grade and reflect ADG differences across treatments. Cattle fed silage consumed less, gained the same, and had greater G:F (P < 0.01). Based on numerically less HCW, ADG, and poorer G:F, these data suggest that feeding 6% corn stalks did not produce similar performance as feeding 12% corn silage. These data suggest that feeding 15% distillers was not enough to offset decreased quality roughage (stalks) compared with silage as roughage which contradicts previous studies when 30% distillers were fed.
264 Evaluation of Precision Feeding on Production Efficiency Responses in Finishing Beef Cattle
Authors: Hanson Santana , Rusche Warren C , Smith Zachary K
Published: October 2023

Charolais-Angus cross steers (n = 128; initial shrunk BW = 505 ± 32.1 kg; n = 16 pens; 8 replicate pens/treatment) were used in a 94-day finishing phase experiment to evaluate animal growth performance outcomes, efficiency measures, and carcass characteristics when varying degrees of ingredient inclusion tolerances were imposed. Treatments included: 1) Normal feeding with 0.454 kg tolerance for all ingredients (FXD) and 2) Variable inclusion strategy where each ingredient was randomly increased or decreased but the targeted as-fed quantity for the daily delivery was met (VAR). All steers were fed twice daily with all bunks managed using a slick bunk approach. Ractopamine HCl was fed (300 mg per head daily) for the final 28 d. Individual BW measures were captured at processing approximately every 35 d. Diets consisted of high-moisture corn (HMC), dry-rolled corn (DRC), dried distillers grains plus solubles (DDGS), liquid supplement (LS), and grass hay (GH) for the first 40 days of the finishing period. Days 41-94 diets consisted of DRC, LS, DDS, GH, and corn silage (CRNSIL). Ingredient inclusions were randomized by assigning independently a random integer to HMC, GH and DDGS with each integer corresponding to the deviation from targeted inclusions; LS inclusion was held constant. As-fed inclusion rates varied from formulated targets by -20, -15, -10, -5, 0, +5, +10, +15, or +20%. DRC or CRNSIL was adjusted so that the targeted as-fed amount of the diet was delivered each day. Data were analyzed using the GLIMMIX procedure of SAS 9.4 (SAS Inst. Inc., Cary, NC) with pen as the experimental unit and block as random effect. VAR steers had increased (P ≤ 0.01) dry matter intake (DMI) and reduced (P ≤ 0.02) kg of gain to kg of feed (G:F). However, no differences (P = 0.75) were detected between treatments for ADG. In addition, net energy for maintenance and gain was decreased (P ≤ 0.01) in VAR. Carcass characteristics for both treatments showed no significance (P ≥ 0.38) in HCW, dressing percentage, rib eye area, rib fat, KPH, yield grade, retail yield, empty body fat, or body weight at 28% estimated EBF. A tendency for increased USDA marbling score (P > 0.08) was noted in VAR. Under the conditions of this experiment, randomly altering ingredient proportions did impact growth performance and efficiency measures. However, despite the difference in growth efficiency carcass characteristics were not impacted.