bluuebunny/crossref_metadata_2025 huggingface dataset:
142 Evaluation of Proso Millet as a Partial or Complete Replacement for Corn in Growing-finishing Diets for Pigs
Authors: Nguyen Khang A , Trenhaile-Grannemann Melanie D , Burkey Thomas , Miller Phillip
Published: May 2021

An experiment was conducted to evaluate the effects of increasing the inclusion of proso millet on the growth performance of growing and finishing pigs. Using a randomized complete block design, 36 crossbred barrows, with an average initial weight of 22.2 kg, were randomly assigned to 1 of 4 dietary treatments (9 pens/treatment; 1 pig/pen). Diet 1 was corn-soybean meal-based (control) and Diets 2, 3, and 4 had proso millet replacing 33%, 67%, and 100%, respectively, of corn in the control diet. The diets were formulated according to 4 growth phases (P1, 25 to 50 kg BW; P2, 50 to 75 kg BW; P3, 75 to 100 kg BW; and P4, 100 to 135 kg BW) with nutrient contents formulated according to NRC (2012) recommendations. Data were analyzed using the GLIMMIX procedure of SAS, using pig as the experimental unit. In P1 and P2, no differences in average daily gain (ADG) or average daily feed intake (ADFI) were observed among treatments (P > 0.3). In P3, pigs consuming the proso millet diets had greater ADFI than pigs consuming the basal diet, especially pigs fed Diet 4 compared to pigs fed Diet 1 (3.66 vs. 3.29 kg; P < 0.01). The ADG:ADFI ratio was not affected (P > 0.1) by treatments during this period. In P4, although there was a difference in ADFI between pigs fed Diet 3 and Diet 1 (3.8 vs. 3.47 kg; P = 0.04), no decreases in ADG:ADFI ratio were observed among the four dietary treatments (P > 0.5). Average daily gain was not affected (P > 0.3) by treatments during the growing-finishing period, suggesting that the level of corn replacement up to 100% by proso millet did not affect pig growth. In conclusion, proso millet was shown to effectively replace corn in corn-soybean meal-based diet for growing-finishing pigs without compromising growth performance.
141 Relationship Between Dietary Fiber and Basal Ileal Endogenous Losses of Amino Acids in Growing Pigs
Authors: Park Chan Sol , Ragland Darryl , Adeola Olayiwola
Published: May 2021

Two experiments were conducted to determine the influence of sources or concentrations of dietary fiber in nitrogen-free diets (NFD) on basal ileal endogenous losses (BEL) of amino acids (AA) and subsequent standardized ileal digestibility (SID) of AA in feed ingredients for pigs derived from such BEL. In Exp. 1, 20 pigs (initial body weight = 46.5 ± 2.97 kg) were assigned to five diets in a quadruplicate 5 × 2 incomplete Latin square design with two periods. Three NFD containing cellulose (insoluble and fermentable fiber), inulin (soluble and fermentable fiber), or carboxymethyl cellulose (CMC; soluble and non-fermentable fiber) at 40 g/kg plus two diets containing soybean meal (SBM) or wheat distillers’ dried grains (WDDG) as the sole source of nitrogen were prepared. Pigs fed NFD containing CMC had greater (P < 0.05) BEL of AA, except for Arg and Pro, than those fed the other NFD. The SID of most AA in SBM and WDDG corrected by BEL of AA from NFD containing CMC were greater (P < 0.05) than those corrected by BEL of AA from the other NFD. Experiment 2 was conducted with 21 barrows (initial body weight = 34.1 ± 2.57 kg) assigned to seven diets in a triplicate 7 × 3 incomplete Latin square design with 3 periods. Seven diets consisted of three NFD containing 4, 8, or 12 g/kg cellulose and four diets containing corn, wheat, SBM, or canola meal as the sole source of nitrogen. There was no difference in the BEL of AA, except for Pro, among pigs fed NFD with increasing concentration of cellulose. The SID of AA in test ingredients were not affected by BEL of AA from NFD containing increasing concentration of cellulose. In conclusion, chemical characteristics of dietary fiber, but not concentration, affect the BEL of AA in pigs.
143 Impact of Replacing Soybean Meal with Corn DDGS and Crystalline Amino Acids on Performance and Carcass Characteristics of Growing Pigs
Authors: Anderson Brooke E , Holt Jon P , Boyd R D , van Heugten Eric
Published: May 2021

This study evaluated the effect of replacing soybean meal (SBM) with DDGS and crystalline amino acids on growth and carcass lean. Pigs (n = 512; 38.51±0.13 kg BW) were blocked by BW and sex and placed in 64 pens (4 gilts and barrows per pen). Treatments were arranged as a 2×4 factorial with DDGS included at 0 or 25% and L-lysine-HCl (LYS) added at 0, 0.2, 0.4, and 0.6%. Dietary SBM inclusion declined as LYS increased from 32.06 to 13.14% (Phase 1) and 28.25 to 9.40% (Phase 2) for control diets. It declined from 27.85 to 8.89% (Phase 1) and 24.05 to 5.10% (Phase 2) for DDGS diets. Diets contained 1.00 (Phase 1, 21 days) and 0.90% (Phase 2, 18 days) SID lysine and were balanced for ideal protein and net energy. During Phase 1, DDGS decreased ADG (P = 0.06; 786 vs. 821 g/d). Increasing LYS increased (quadratic, P ≤ 0.05) ADG and ADFI with the greatest response at 0.4% LYS. G:F decreased (linear, P = 0.035) with increasing LYS. During Phase 2, increasing LYS in control, but not DDGS diets, decreased (linear, P < 0.005) ADG and ADFI. G:F declined (P = 0.054) with DDGS inclusion (370 vs. 383 g/kg). Overall, ADG decreased (linear, P = 0.005) as LYS increased in control (959, 929, 908, 860 g/d), but not DDGS diets (863, 908, 931, 832 g/d). ADFI decreased (linear, P = 0.014) with increasing LYS in control (2270, 2198, 2186, 2130 g/d), but increased (quadratic, P = 0.039) in DDGS diets (2112, 2207, 2324, 2103 g/d). DDGS reduced (P≤0.03) ADG (883 vs. 914 g/d), G:F (405 vs. 417 g/kg) and LEA (34.5 vs. 35.3 cm2), while increasing LYS decreased (linear, P < 0.005) G:F (417, 419, 409, 401 g/kg) and LEA (35.34, 35.17, 35.46, 33.64 cm2). Displacement of SBM with DDGS reduced growth and LYS addition negatively affected growth and G:F for diets with SBM, but not DDGS.
136 Mycotoxin Contamination in United States Corn and Corn DDGS from 2019 and 2020 Harvest
Authors: Zheng Lan , Pender Chasity , Gott Paige N , Schwandt Erin F , Ramirez Shelby M , Hofstetter Ursula , Murugesan G Raj
Published: May 2021

Mycotoxins are harmful secondary fungal metabolites central to food and feed safety management. These toxins are detrimental to animal health and even at low levels can compromise performance. Focus on clinical signs like decreased feed intake and vomiting overlook significant impacts of mycotoxicosis, including increased disease incidence and severity, immune dysfunction, inflammation, and modulation of the gastrointestinal environment. The objective of this study was to determine the effect of harvest year on five major mycotoxin groups: aflatoxins (Afla), type A trichothecenes (A-Trich), type B trichothecenes (B-Trich), fumonisins (FUM), and zearalenone (ZEN) in corn and corn DDGS samples. For each mycotoxin group within ingredient, 2019 harvest (329 corn and 20 corn DDGS) were compared with 2020 harvest (27 corn and 21 corn DDGS). Data were analyzed using GLIMMIX procedure of SAS with harvest year as fixed effect and sample as the experimental unit. Average B-Trich and FUM contamination levels in corn are significantly (P < 0.05) affected by harvest year. However, B-Trich levels remained consistent, whereas FUM decreased (P < 0.05) from 2019 to 2020. Contamination levels in corn for Afla, A-Trich, and ZEN have remained consistent (P > 0.05) from 2019 to 2020. In corn DDGS, B-Trich contamination level was decreased (P < 0.05) from 2019 to 2020, whereas FUM and ZEN contamination levels remained similar (P > 0.05). The 2020 crop risk profile is likely to change as the sample pool expands. A combination of hot weather, storm events, and drought during the 2020 growing season resulted in crop stress and damage, ultimately leading to grain quality and mycotoxin contamination concerns. Due to the continued risk of mycotoxin co-occurrence, expanding mitigation strategies beyond adsorption by mycotoxin deactivation with biotransformation and additional support of immune and liver function is essential.
134 Meta-analysis to Determine the Effects of Particle Size on Nursery and Finishing Pig’s Growth Performance and Stomach Morphology
Authors: Kippert Carlos J , Vier Carine M , Lu Ning , Cast Wayne R , Navales Ron A , Dritz Steve S , Orlando Uislei A
Published: May 2021

A meta-analysis was conducted to determine grain particle size (PS) effects on pig growth performance and stomach morphology. Data from 29 trials (11 in the nursery and 18 in the finisher) published from 1986 to 2016 for a total of 140 observations were recorded in a database. The response variables were average daily gain (ADG), average daily feed intake (ADFI), gain-to-feed ratio (G:F), ulceration and keratinization scores. Tested predictors included the interactions between PS linear and quadratic effects, production phase, diet form, and main effects of grain type, ingredient inclusion, and mill type. Trial was included as a random effect. Data were analyzed with the lmer function from the lme4 package in R. Significant predictors (P < 0.05) and with improved model fit remained in the final model. Results indicated a significant interaction (P < 0.05) between diet form and quadratic PS for ADFI and G:F. Nursery and finishing pigs fed meal diets linearly reduced ADFI and improved G:F as PS reduced. Nursery pigs fed pelleted diets had reduced ADFI and improved G:F with PS reduced to 500–600µ, with increased ADFI and poorer G:F at lower PS. Finishing pigs fed pelleted diets had reduced ADFI and improved G:F with PS reduced to 500–600µ, with no further changes at lower PS. Regardless of diet form and production phase, ADG increased (quadratic, P < 0.05) as PS reduced until approximately 600µ and decreased at lower PS. There was no evidence of PS effect on ulceration score (P = 0.12). Keratinization score increased (P < 0.05) as PS decreased. Reducing PS in meal diets linearly increased keratinization scores, reduced ADFI, and improved G:F. However, no further benefits in performance were observed at grain PS below 500–600µ in pelleted diets.
218 Ileal Digestibility of Amino Acids Is Greater in Sunflower Expellers Than in Sunflower Meal When Fed to Growing Pigs
Authors: Ibagon Jimena A , Lee Su A , Stein Hans H
Published: May 2021

An experiment was conducted to test the null hypothesis that country of origin and oil extraction method does not affect the standardized ileal digestibility (SID) of AA in sunflower co-products. Six sources of sunflower meal (SFM) and one source of sunflower expeller (SFE) were obtained from Ukraine, Hungary, Italy, and the United States. Eight barrows (initial BW: 28.5 ± 2.4 kg) that had a T-cannula installed in the distal ileum were housed individually and allotted to an 8 × 8 Latin square design with 8 diets and eight 7-d periods. Each source of SFM or SFE was included in one diet as the only source of CP and AA. A nitrogen-free diet was also used. Data for SFM were analyzed using PROC MIXED of SAS with the fixed effect of ingredient and the random effects of animal and period. A contrast statement was used to compare results for SFM and SFE. Pig was the experimental unit and an alpha value of 0.05 was used. Results indicated that the SID of most AA in SFM sources 2 and 6 were greater (P < 0.05) than in source 4, but the SID of Lys, Met, and Trp were not different among the 6 sources of sunflower meal (Table 1). The SID of all AA, except Trp, was greater (P < 0.05) in SFE compared with SFM. In conclusion, differences in the SID of all AA except Lys, Met, and Trp in SFM sourced from Ukraine, Hungary, Italy, or the United States were observed, but the SID of all AA, except Trp, was greater in SFE than in SFM indicating that country of origin or site of production as well as oil extraction method influence SID of AA.
246 Effects of Feeding Thermally Processed Spray-dried Egg Whites on Growth Performance, Apparent Digestibility, and Oxidative Stress in Nursery Pigs
Authors: Wilson Victoria C , Kerr Brian J
Published: May 2021

The objectives of this study were to determine if feeding thermally processed (TP, heated at 100°C for 120 h) spray-dried egg whites (SDEW) to nursery pigs would impact growth performance, apparent total tract digestibility (ATTD) of GE, N, and S, and oxidative stress. Thirty-two barrows, (initial BW 7.1 kg) were randomly assigned to dietary treatments with 1 pig per pen. In a preliminary study, thermally processing SDEW at 100°C for 120 h increased protein carbonyls (PC) from 6 µmol/g to 19.4 µmol/g (P ≤ 0.01). Diets included either 12% SDEW, 6% TP-SDEW plus 6% SDEW, or 12% TP-SDEW. The experiment lasted 24 d for collection of growth performance data, while plasma was collected on d 21 and liver tissue harvested on d 24 to analyze for markers of oxidative stress. Feces were collected on d 22 for measures of ATTD. Daily gain, daily feed intake, feed efficiency, and ATTD of GE were not found to be different among dietary treatments (P ≥ 0.57). In contrast, ATTD of N (P = 0.11) and S (P = 0.03) were found to increase with increasing protein oxidation in the diet. There was no change in the plasma or liver F2-isoprostanes and 8-hydroxy-2’-deoxyguanosine among dietary treatments (P ≥ 0.28). An increase in plasma PC (P = 0.02) was observed in pigs fed 12% TP-SDEW compared to pigs fed 12% SDEW and pigs fed 6% TP-SDEW. In contrast, a decrease in liver tissue PC (P = 0.04) was observed in pigs fed 6% TP-SDEW compared to pigs fed 12% SDEW and 12% TP-SDEW. These results indicate that feeding TP-SDEW does not affect growth performance, ATTD of GE, and oxidative stress as indicated by F2-isoprostanes or 8-hydroxy-2’-deoxyguanosine; but appeared to have variable effects on oxidative stress as measured by PC.
244 Effect of Fiber Source and Crude Protein Level on Nursery Pig Performance
Authors: Hammers Kelsey , Calderon Hilda I , Tokach Mike D , Woodworth Jason C , Goodband Robert D , Dritz Steve S , DeRouchey Joel M
Published: May 2021

A total of 360 pigs (DNA 200′400, initially 5.0 kg) were used in a 45-d growth trial to determine the effects of fiber source and crude protein (CP) level in diets without pharmacological levels of ZnO on nursery pig growth performance and fecal dry matter (DM). Pigs were randomly assigned to 1 of 8 treatments with 5 pigs/pen and 9 pens/treatment. Treatments were arranged in a 2×4 factorial with main effects of CP (21 or 18%) and fiber source [none, coarse wheat bran (CWB), oat hulls, or cellulose (Arbocel, J. Rettenmaier USA, Schoolcraft, MI)]. Fiber source was added to equalize the level of insoluble fiber contributed from 4% CWB, resulting in the addition of 1.85% oat hulls or 1.55% cellulose. Diets were fed in two phases (d 0 to 10 and 10 to 24) followed by a common diet (d 24 to 45). The 21% CP diets contained 1.40% SID Lys in phase 1 and 1.35% SID Lys in phase 2. Treatment diets were formulated to a maximum SID Lys:digestible CP level of 6.35%, thus SID Lys decreased in the 18% CP (1.25% SID Lys) diets. Data were analyzed using the lmer function in R. No fiber source × CP level interactions (P >0.05) were observed. Decreasing dietary CP decreased (P = 0.05) ADG, G:F, and d 24 BW. Overall, ADG and d 45 BW decreased (P < 0.05) for pigs fed 18% CP diets. No main effects of fiber source were observed for growth performance throughout the study. Fecal DM increased (P < 0.05) for pigs fed added cellulose compared to pigs fed no fiber or CWB in the experimental period. In conclusion, reducing dietary CP decreased growth performance and the inclusion of cellulose improved fecal DM of nursery pigs.
243 Effects of Initial Nursery Diet Budget on Growth Performance of 5.5- to 23-kg Pigs
Authors: Cemin Henrique S , Swalla Luke A , Pietig Jamie L , Hansen Sharlie A , Hansen Ernie L
Published: May 2021

An experiment was conducted to determine the effects of the initial nursery diet budget on growth performance. A total of 3,264 pigs (initial BW = 5.5 kg), placed in pens with 51 pigs each, were used in a 45-d trial. There were 4 treatments consisting of different feed budgets of the initial nursery diet: 4.1 kg, 5.4 kg, 6.8 kg, or 8.2 kg. The experimental diet was corn, soybean meal, and whey permeate-based and contained 1.38% SID Lys. After the allocated budget was consumed, pigs were provided a common corn and soybean meal-based diet. There were 16 replicates per treatment. Pigs were weighed weekly to calculate ADG, ADFI, and G:F. Data were analyzed with SAS MIXED procedure. In the first 14 d of the trial there was no evidence for differences (P > 0.10) in growth performance as all pigs were receiving their allocated budget of the initial diet. From d 14 to 21 as well as d 0 to 21, pigs that received a budget of 6.8 or 8.2 kg had improved ADG (quadratic, P < 0.05) and G:F (linear, P < 0.05) compared to those fed budgets of 4.1 or 5.4 kg. From d 21 to 45, when all pigs received a common diet, there was no evidence for differences (P > 0.10) in ADG. However, there was a linear response (P < 0.05) in G:F, with pigs previously fed the lowest feed budget presenting improved G:F. Overall (d 0 to 45), there was an improvement (linear, P < 0.05) in ADG and ADFI as feed budgets increased, with the best performance observed when pigs were fed 6.8 or 8.2 kg of the initial nursery diet. In conclusion, providing a 6.8 or 8.2 kg budget of the initial nursery diet resulted in improved overall nursery performance.
267 Evaluating the Interaction Between Nursery Diet Complexity and Pharmacological Zinc and Copper
Authors: De Mille Carson M , Gabler Nicholas K
Published: May 2021

Weaned pigs are typically fed complex, highly digestible diets to maximize feed intake and weight gain as they transition into the nursery. Further, pharmacological concentrations of zinc (Zn) and copper (Cu) are commonly fed to mitigate weaning-related diarrhea and performance reductions. A 2 x 2 factorial design was utilized to determine the effect of diet complexity with or without Zn and Cu. Four-hundred and thirty-two weaned pigs were randomly allotted to 48 pens (n = 9 pigs/pens). Pens were assigned to one of four diets: 1) A high soybean meal diet (Simple), 2) Simple + ZnCu, 3) Low soybean meal diet with spray-dried plasma, casein, and oats (Complex), and 4) Complex + ZnCu. Diets were fed in two 14 d phases. For ZnCu there were 3,000 and 2,000 ppm Zn in phase 1 and 2, and 200 ppm Cu in both phases. Bodyweight and feed intake were determined in phase 1 (d 0–14) and phase 2 (d 15–28). Pen was the experimental unit and all data were analyzed by diet complexity, pharmacological minerals and their interaction. No complexity by ZnCu interaction or diet complexity effects were observed in the 28 d study. However, ZnCu increased ADG (0.23 vs. 0.16 kg/day, P < 0.0001), ADFI (0.28 vs. 0.24 kg/d, P < 0.0001), and GF (0.80 vs. 0.69, P < 0.0001) in phase 1. In phase 2, ZnCu increased ADG by 9% (P = 0.008) and ADFI by 16% (P = 0.0001) compared to non-supplemented counterparts. Overall (0–28 d), ZnCu pigs had heavier end bodyweight (15.9 vs. 14.5 kg, P = 0.009), and greater ADFI (0.47 vs. 0.41 kg/d, P < 0.0001). In conclusion, diet complexity (high levels of soybean meal versus specialized protein alternatives) did not alter nursery performance. Irrespective of diet complexity, pharmacological Zn and Cu improved performance parameters.
271 Investigating the Relationship Between Nursery Pig Performance and Markers of Intestinal Morphology and Integrity
Authors: De Mille Carson M , Gabler Nicholas K
Published: May 2021

Weaning induces major structural and function changes to the small intestine of pigs and they transition from milk to solid feedstuffs. Thus, the objective of this study was to determine how intestinal morphology and function markers relate to feed intake and growth rates of nursery pig. Forty-eight weaned pigs (5.63 ± 0.50 kg) were randomly selected, individually penned and fed a common diet. Pig bodyweights and feed intake were determined at d 2, 7, and 21. At each time point, 16 pigs were randomly selected and euthanized. Sections of ileum were assessed for morphology [villus height (VH), crypt depth (CD) and VH:CD] and ex vivo transepithelial resistance (TER), macromolecule permeability (FD4), and active transport of glucose and glutamine via modified Ussing chambers. Within each period (d 0–2, 0–7, and 0–21), Pearson correlations were performed between ADG, ADFI, VH, VH:CD, TER, FD4 and active transport of glucose and glutamine. At d 2 post-weaning, no correlations (P > 0.05) were observed between performance and intestinal variables. By d 7, moderate positive correlations between VH and ADFI (r = 0.69, P = 0.005), VH and ADG (r = 0.68, P = 0.006) were reported. At 21 d post-weaning, moderate positive correlations were still observed for VH and ADFI (r = 0.55, P = 0.026) and between VH and ADG (r = 0.51, P = 0.042). Interestingly, ADFI and ADG tended to be negatively correlated with active glucose transport (r = -0.45, P = 0.083 and r = -0.47, P = 0.064, respectively) and active glutamine transport (r = -0.45, P = 0.083 and r = -0.46, P = 0.073, respectively). Markers of ileal integrity (TER and FD4) were not correlated with ADG or ADFI at any time point. Altogether, these data highlight the importance of intestinal morphology on early nursery pig performance.
104 The Danish Perspective to Remove Medicinal Zinc and Reducing the Use of Antibiotics in Swine Production
Authors: Maribo Hanne
Published: May 2021

Diarrhoea in weaners has been commonly controlled by adding medicinal zinc (2500 ppm), but by June 2022 this was no longer allowed. In Denmark, antibiotics are accepted for therapeutic use only and usage is registered on pen level and is monitored by Danish authorities. This increases the risk of post-weaning diarrhoea. SEGES has tested several tools, additives e.g. organic acids, diet composition, raw materials e.g. blood plasma. Lowering the protein level in the diet post-weaning is very efficient, but adversely affects productivity. The latest results show on average that a reduction in protein from 19% to 15% in the weaner diet (6-9kg) results in a 60% reduction in diarrhoea; however, it also leads to a productivity loss of 1-1,5 euro. Reducing the protein level from 19% to 16,5% reduces the frequency of diarrhoea by 30% and the productivity loss by approx. 0,3 euro. A trial testing the possibility for compensation for this loss in the weaner period by adding extra protein and amino acids in the finisher diet (30–115 kg) is running now and preliminary results will be presented. Further results from trials reducing diarrhoea by reducing protein, a new way to calculate ideal protein and amino acid balances as well as results from concept tests with weaners will be presented. Further new results evaluating ideal protein and amino acid balances will be presented.
106 Agriculture Residues as a Possible Sustainable Approach to Replacing Antibiotics in Animal Nutrition
Authors: Ekmay Ricardo
Published: May 2021

The last several years has seen a substantial increase in the investment and development of alternative proteins to lower the environmental footprint of animal agriculture. In addition to insects, single cell proteins (SCP), i.e. algae, bacteria, yeast, have received renewed attention due to their ability to utilize unconventional carbon feedstocks. Traditionally, conventional sugar streams such as corn syrup or molasses have been used for cultivation of SCP. However, algal and bacterial meals are looked at as potential solutions for industrial carbon waste such as carbon dioxide and methane. Yeasts have the ability to use pentose sugars that are found in lignocellulosic materials, i.e. agricultural and forestry residues. Much of the discourse surrounding these alternative protein sources has been on the environmental impact of their production, but less so on the impact of their use. In particular, the impact of single cell proteins on nutrient utilization and gastrointestinal health warrants attention. Nutritional value remains varied among SCP products and dependent on microbial strain and down-stream processes. Maintaining high protein digestibility, and reducing fermentable protein, as well as maintaining high phosphorus digestibility remains a critical nutritional and environmental strategy. Recent findings have indicated that the microbial strain and the carbon feedstock on which it is grown on may have an interactive effect on gastrointestinal health. In particular, yeast products can be characterized as generally anti-inflammatory, but cultivation on lignocellulosic residues appears to enhance these properties. Bacterial meals are known to contain pro-inflammatory components such as lipopolysaccharides and peptidoglycans, however, in some instances, they may also produce bioactive molecules that result in a net positive impact. It remains critical to evaluate alternative proteins in the context of whole animal health and consider the environmental impact of their use as well as their production.
80 Use of an Electronically-controlled Floor Cooling Pad During Heat Stress on Thermoregulatory and Reproductive Performance in Boars
Authors: Shirley Larissa K , Field Tyler , Schinckel Allan P , Johnson Jay S , Stwalley Robert , Stewart Kara R
Published: May 2021

This study was designed to evaluate the effects of electronically-controlled floor cooling pads on thermoregulatory and reproductive parameters in boars during heat stress (HS). Boars (n = 24) were randomly assigned to crates with non-functional pads (CON) or pads that were flushed in either 8-min intervals or when the pad reached 28.5°C (FLUSH). For 3 d, boars were subjected to cyclical HS (28 to 35°C; >65% relative humidity). Boars were fed 2.4 kg/d and daily feed intake was recorded. Respiration rate (RR), rectal temperature (Rtemp) and skin temperature were recorded every 2 h during HS (via IR camera), testicular temperature was recorded twice daily. Semen was collected d7 and d14 before HS, the day following HS and weekly for 6 weeks and evaluated for volume, sperm concentration, motility, progressive motility, morphological abnormalities, and viability. After 2 h of HS, FLUSH boars had reduced RR (P < 0.001) and RTemp (P < 0.001) when compared to control boars, and this difference was maintained throughout HS. Skin and testicular temperature were reduced in FLUSH vs. CON boars after 6 h of HS (P < 0.05). Semen volume was greater in FLUSH vs CON boars (P = 0.01) resulting in a tendency for an increase in total sperm per ejaculate (P = 0.075). From weeks 2 to 5 post-HS, FLUSH boars had increased motility (P = 0.006) and progressive motility (P = 0.001), with corresponding increases in sperm kinematic motion parameters when compared to CON boars. The number of morphologically normal sperm cells were increased (P = 0.006) in FLUSH vs CON boars due to reduced distal droplets (P = 0.033) and proximal droplets (P < 0.001). Abnormal acrosomes were reduced (P < 0.001) in FLUSH vs CON boars at week 3 post-HS. In summary, electronically controlled cooling pads effectively reduced negative thermoregulatory indicators of HS and minimized or removed the negative impacts of HS on semen quality in boars.
81 Zearalenone Affects the Ovarian Proteome During Heat Stress in Prepubertal Gilts
Authors: Roach Crystal M , Mayorga Edith J , Baumgard Lance H , Ross Jason W , Keating Aileen F
Published: May 2021

Zearalenone (ZEA), an estrogenic mycotoxin, causes hormonal disruption and reproductive dysfunction in pigs. Heat stress (HS) occurs when exogenous and metabolic heat accumulation exceeds heat dissipation; a scenario negatively impacting gilt reproduction. Our objective was to identify differentially abundant ovarian proteins in gilts exposed to HS +/- ZEA. We hypothesized that ZEA exposure would negatively impact the prepubertal gilt ovarian proteome and HS would be additive to ZEA-induced toxicity. Prepubertal gilts (n = 38) were assigned to one of six treatment groups: thermoneutral (TN) ad libitum control (TNCtl; n = 6); TN + ZEA (TNZea; 2 ppm; n = 6); pair-fed (PF) control (PFCtl; n = 6); PF+ ZEA (PFZea; 2 ppm; n = 6); cyclical HS control (HSCtl; n = 7); and HS + ZEA (HSZea; 2 ppm; n = 7). Gilts were subjected to TN (20 ± 1°C) or cyclic HS (35 ± 1°C for 12 h/31.6° for 12 h) conditions for 7 d. Liquid chromatography-mass spectrometry (LC-MS/MS) was performed on ovarian protein homogenates. Exposure to ZEA altered (P < 0.05) abundance of 93 proteins in TN gilts (48 increased and 45 decreased). In PF gilts, ZEA increased 50 and decreased 47 proteins (P < 0.05). During HS, ZEA differentially affected (P < 0.05) 126 proteins: 58 increased and 68 increased. Pathways impacted by either HS or ZEA alone or in combination included cellular stress, metabolic pathways, and estrogenic pathways. Thus, ZEA and HS, either alone or in combination, impact the ovarian proteome in prepubertal gilts in ways that could contribute to seasonal infertility. This project was supported by the Iowa Pork Producers Association.
84 Aging Model in Pig Oocytes as Viewed Through DNA Epigenetic Modification
Authors: Arena Haley A , Sprungl Kimberly , Reynolds Skyla , Whitaker Brian D
Published: May 2021

Oocytes of older animals are less likely to be fertilized during the optimal time window post ovulation, resulting in the potential diminished fertilization and embryonic development success. The activity of the epigenetic modifications during this period is a possible target to reverse these damaging effects of aging. The objective of this study was to study the effects of aging during in vitro oocyte maturation in pigs on epigenetic modifications. Oocytes (n = 54) were matured with or without Trichostatin A (TSA; 100 ng/mL), a known meiotic inhibitor, for 24 h, then for an additional 16 h without TSA or hormones for a total of 40 h. At the end of maturation, oocytes were denuded and their zona pellucida’s removed. Oocytes were stained with anti-5-methylcytosine (5mC, 1:500). Fluorescent images of the oocytes were acquired, images were analyzed using ImageJ, and data analysis was performed using ANOVA and Tukey’s test. Oocytes matured with TSA had significantly greater (P < 0.05) levels of DNA methylation by the end of in vitro maturation compared to those not supplemented with TSA These results suggest that TSA can be used to develop an in vitro model to study the effects of epigenetic modifications in oocytes from aged livestock.
258 The Interactions of Change in Nutrition on Uterine Environment and Plasma Cholesterol Concentrations in Beef Cattle
Authors: Andrews Taylor , Epperson Kaitlin , Rich Jerica , Zoca Saulo Menegatti , Zezeski Abigail L , Geary Thomas W , Lawrence Rhea D , Walker Julie , Perry George
Published: May 2021

The objective was to evaluate the impact of nutritional changes prior to and after artificial insemination (AI) on uterine environment and plasma cholesterol concentrations. Beef heifers (n = 79) were randomly assigned to two dietary treatment groups (High=155% or Low=86% of maintenance energy) for 30 d prior to AI (pre-AI). At AI, heifers were randomly assigned new treatment groups (post-AI) which created four pre- x post-AI diet treatments (High-High, High-Low, Low-High, and Low-Low). Post-AI dietary treatments continued until uteri were flushed for embryo recovery (d 7 or 8 post-AI). Blood samples were collected on d -3,-2,-1, 0 (AI day), 1,3,5,7, and 8 for analysis of plasma cholesterol concentrations using a colorimetric assay. Uterine flushes were analyzed for concentrations of Mg, Al, P, S, K, Ca, Cu, Zn, Se, and Fe by ICPMS. Plasma cholesterol (repeated measures) and uterine mineral concentrations were analyzed using the MIXED procedures in SAS. Plasma cholesterol concentrations changed over time (P < 0.0001); however, there were no differences between treatments (P > 0.10). There was an effect of embryo presence on uterine flush mineral concentrations for Mg (P < 0.04), Al (P < 0.01), S (P < 0.01), K (P < 0.01), and Ca (P < 0.01), with decreased concentrations when uterine flushes contained an embryo. There was no effect of pre-AI diet on mineral concentrations; however, there was an effect of post-AI diet on S (P < 0.02) and Ca (P = 0.03). High diet heifers had increased S and Ca concentrations compared to low diet heifers. Sulfur concentration was affected by a pre-AI diet by embryo interaction (P < 0.03). There was a post-AI by embryo interaction on P (P < 0.03), Zn (P = 0.02), and Se (P = 0.02). Also, there was a pre-AI by post-AI by embryo interaction on Mg (P < 0.05). In conclusion, changing plane of nutrition pre- and post-AI had no effect on plasma cholesterol concentrations; however, presence of an embryo affected uterine mineral concentrations.
289 Serum Trace Minerals in Late Gestation Sows at Variable Risk for Pelvic Organ Prolapse
Authors: Kiefer Zoe E , Chipman Amanda , Showman Lucas , Keating Aileen F , Ross Jason W
Published: May 2021

Within the last decade, pelvic organ prolapse (POP) resulting in sow mortality has become an increasing concern for the U.S. swine industry, contributing approximately 21% of all sow deaths. While little is known regarding the etiology preceding POP in sows, many have proposed an association with vitamin and trace minerals abundance to POP incidence. We tested the hypothesis that sows differing in POP risk would have differences in serum trace minerals and vitamins. A perineal scoring (PS) system (PS1 - presumed low risk; PS2 - presumed moderate risk; and PS3 - presumed high risk) to assess risk for POP during late gestation was used to score 213 individual sows. Blood was collected from sows of two different farms during late gestation (days 105–115) that scored a PS3 (n = 20) and a parity matched sow scored as PS 1 (n = 16). Subsequently, 1.5, 0.8, and 23.1% of sows scored as PS1, PS2, or PS3, respectively, experienced POP. Serum was analyzed at the Iowa State University Veterinary Diagnostic Lab for trace mineral content (Calcium, Copper, Iron, Potassium, Magnesium, Manganese, Molybdenum, Phosphorus, Selenium, and Zinc). Additionally, vitamin E was evaluated in serum via GC-MS. Differences (P < 0.05) in copper, potassium, molybdenum, phosphorus, and selenium was observed between farms. Further a PS x Farm interaction (P = 0.06) was observed for serum copper abundance which across all farms was 12% less (P < 0.04) in PS3 compared to PS1 sows. No impact on serum vitamin E was observed between PS sows. These data demonstrate sows with greater POP risk may have potential differences in serum factors although these data also underscore the importance of measuring vitamin and mineral quantities in a tissue specific manner. This project was supported by the National Pork Board and the Foundation for Food and Agriculture Research.
288 Plasma Concentrations of Cortisol During the Periparturient Period in Gilts
Authors: Dierking Shannon , Everding Talia , Morton Jodi , Clapper Jeffrey A , Levesque Crystal L
Published: May 2021

An increase in plasma concentrations of cortisol is one signal that begins parturition and uterine contractions in pregnant sows; however, it is not known whether a critical level of cortisol is necessary or the role that it may play in the duration of parturition. The objective of the study was to characterize plasma concentrations of during the periparturient period and assess its relationship with initiation of parturition, litter size, and farrowing duration. Blood was collected via indwelling catheters from 5 primiparous gilts twice daily (0700 and 1900 h) from d113 of gestation until the birth of the first piglet, after which blood was collected every 15 minutes until farrowing was considered complete. Time of birth of each piglet was recorded. Farrowing duration was defined as the time between birth of the first and last piglets. Plasma concentrations of cortisol were determined by radioimmunoassay. Litter size was 12, 12, 18, 17, and 14 piglets and farrowing duration was 72 minutes, 4.1, 6.7, 5.8, and 4 hours, respectively. Quadratic and linear regressions were performed using the RStats package in RStudio (version 1.2.5025). Serum concentrations of cortisol were 3.37 ± 1.55 and 5.73 ± 2.18 ng/mL prior to parturition and at the birth of the first piglet, respectively. There was a positive quadratic relationship (P ≤ 0.07) between time of birth of each piglet and plasma cortisol levels; peak cortisol was 14.45 ± 3.20 ng/mL. There was a positive correlation between initial cortisol level and average piglet birth weight (P = 0.0124) but no relationship with total litter weight (P > 0.05). Determination of the periparturient changes in cortisol may be useful in designing farrowing induction protocols.
174 What Quality and Fertility Should We Expect When Using Semen Cryopreservation and AI with Livestock? a Comparison Across Species
Authors: Purdy Phillip H
Published: May 2021

Assisted reproductive technologies (ART) can be used across most agricultural species and will result in some degree of fertility when employed correctly. Still, conversations with agricultural producers and scientists (corporate, academic, governmental) repeatedly reveal that they do not know what success rates they should anticipate when using some ARTs, specifically semen cryopreservation and artificial insemination, with agricultural species (beef and dairy cattle, goats, pigs, poultry, sheep). These perceptions hinder ART application within the agricultural and scientific communities. Understanding these expected results is a critical component that is used to guide the USDA National Animal Germplasm Program laboratory operations for collecting, freezing and using germ plasm (semen, eggs, embryos, DNA, tissues, organs, cells), has consequently resulted in growth of the national collection, and provided tools, technologies, and educational opportunities for agricultural producers with documented success. Therefore, the intent of this presentation is to provide an overview of what results should be expected when using semen cryopreservation and artificial insemination across livestock species, explain the factors that influence successful use of these ARTs, which should encourage a more broad acceptance of their use with all agricultural species, and discuss opportunities for research and optimization that will improve fertility when using these technologies.
208 Sperm Retention, Storage and Release from the Oviduct: A Story of Sugars, Steroids, and Channels
Authors: Miller David J
Published: May 2021

Because mating is not always synchronized with ovulation, females from many species store sperm in the female reproductive tract until ovulation and fertilization. This may be done for short periods, a day or two for swine and cattle, or longer periods. Other mammals, such as some species of bats, store sperm for several months. Chickens and turkeys store sperm for 2–4 weeks and queens of some species of insects store sperm for over a decade in specialized structures. How sperm are retained, kept fertile for varying times and released is unclear. We have identified two specific carbohydrate motifs that are abundant in the porcine oviduct that bind and retain sperm in the isthmus. When immobilized, these two glycans lengthen sperm lifespan and suppress the normal increase in intracellular Ca2+ that normally accompanies capacitation. Porcine sperm can be released from oviduct cells and immobilized glycans by progesterone, perhaps of ovarian or cumulus-oocyte complex origin, which activates CatSper, a sperm-specific Ca2+ channel. Progesterone, as well as other compounds that stimulate hyperactivated motility, trigger sperm release, suggesting that hyperactivated motility is sufficient to release porcine sperm from oviduct glycans. We also have found that blocking proteasome-induced sperm protein lysis diminishes the number of sperm released from oviduct glycans. Finally, a transcriptomic approach has identified several groups of genes that are differentially regulated in both bovine and porcine oviducts from estrus animals that are storing sperm compared to oviducts from diestrus animals. This provides clues about how sperm lifespan is extended during storage.
207 Female Reproductive Fluids and Epigenetics
Authors: Canovas Sebastian , Romar Raquel , Coy Pilar
Published: May 2021

Physiological fertilization, and early embryo development, involves dramatic transcriptomic, epigenetic and morphological changes in a short temporal window. During this period gametes and early embryos are surrounded by reproductive fluids (oviductal and uterine), which contain nutrients, growth factors, hormones and extracellular vesicles acting as carriers of DNA, RNA, proteins and other factors with putative roles in intercellular communication. Under in vitro conditions, and in the absence of these fluids, embryos derived from Assisted Reproductive Technologies (ART) reveal transcriptional and epigenetic differences compared with in vivo embryos, which could result in long-term phenotypic consequences in adult life. Therefore, reproductive fluids supplementation in the culture medium offers an alternative to imitate physiological conditions and decrease these consequences. In vitro, oviductal fluid (OF) can modulate capacitation-associated events and sperm-zona pellucida interactions and contribute to the control of polyspermy in pigs. The use of in vitro fertilization media supplemented with reproductive fluids (Natur-IVF) improves embryo quality and blastocysts hatching ability. Moreover, Natur-IVF embryos show expression and methylation patterns closer to in vivo blastocysts. In cows, supplementation of culture media with reproductive fluids, or some isolated factors, improves blastocyst rate and survival after embryo transfer, and reverses the expression of some altered genes. However, considering the complexity of the oviductal and uterine fluids, it seems difficult that the use of just a few factors in isolation can reverse all undesired consequences of the IVP. On the other hand, sex-specific embryonic plasticity, as a consequence of the oviductal regulatory signals, have been proposed. Thus, we have analysed the sex-specific effect of supplementation with reproductive fluids in bovine embryos and data reveal sex-dependent impact in DNA methylation. All these results confirm that developmental programme can be modulated by reproductive fluids and it shows sex-specific effects. This strategy allows the possibility of minimizing undesired in vitro derived consequences.
72 Relationships Among Lifetime Feed Efficiency Traits in Growing Heifers, Mature Cows and Their Progeny
Authors: Lancaster Phillip A , Davis Mike , Rutledge Jack , Cundiff Larry
Published: May 2021

Uncertainty exists in relationships among feed efficiency traits in different production stages. The objective of this study was to evaluate the relationships among feed efficiency traits measured in various stages of production. Data were collected from 1953 through 1980 from dams (n = 160), and their progeny (n = 406). Individual feed intake was measured from 240 d of age through weaning of 3rd calf for dams, and from weaning to slaughter for progeny. Body weight was measured at 28-d intervals until first parturition for heifers and slaughter for progeny, and cows were weighed at parturition and weaning each production cycle. Milk yield of dams was measured at 14-d intervals throughout lactation. Residual feed intake was computed as the residual from linear regression of daily DMI on metabolic mid-test body weight, average daily gain, and milk yield for dams only with year-diet-breed factor as a random effect using lmer function in R software. Pearson correlation coefficients were computed using corr.test function. Pearson correlations of RFI with DMI ranged from 0.58 to 0.74 and with feed:gain or feed:milk ranged from 0.24 to 0.67 within production stage. Heifer RFI was correlated with cow RFI during parity 1 (0.74), but not parity 2 (0.11) or 3 (-0.06). Heifer RFI was correlated with progeny 3 RFI (0.17), but not progeny 1 or 2 RFI. Cow RFI was weakly correlated among parities (0.25 to 0.36) whereas feed:milk was strongly correlated (0.56 to 0.70). Cow RFI was not correlated with progeny RFI of the same parity. In conclusion, RFI was poorly correlated across stage of production.
71 Evaluation of the CVDS Beef Cow Model to Estimate Biological Efficiency in Mature Cows
Authors: Lancaster Phillip A , Davis Mike , Tedeschi Luis O , Rutledge Jack , Cundiff Larry
Published: May 2021

There is no clear method to measure biological efficiency in grazing beef cows. The objective of this study was to evaluate a nutrition model to estimate biological efficiency in mature cows. Data from dams (n = 160) and their 2nd and 3rd progeny were collected from 1953 through 1980. Individual feed intake was measured at 28-d intervals for lifetime of dams and during 240-d lactation for progeny. Body weight of progeny were measured at birth and weaning, and dams at parturition and weaning each production cycle. Milk yield of dams was measured at 14-d intervals by hand milking. Metabolizable energy required (MER) and predicted milk energy yield (MEY) of each cow was computed using the CVDS beef cow model for each parity. Biological efficiency was computed as the ratio of cow ME intake (MEI) to calf weaning weight (WW) based on observed (MEI/WW) and predicted (MER/WW) values. Pearson correlation coefficients were computed using corr.test function in R software. Average (SD) cow weight, calf weaning weight, cow MEI, and observed MEY were 507 (81) and 548 (88) kg, 287 (49) and 294 (44) kg, 9406 (2695) and 9721 (2686) Mcal, and 1009 (538) and 1051 (521) Mcal, for progeny 2 and 3, respectively. Cow MEI and MER (0.87 and 0.85), and observed and predicted MEY (0.51 and 0.51) were positively correlated for progeny 2 and 3, respectively. The CVDS model under predicted cow MEI [mean bias = 1685 (1718) and 1658 (1702) Mcal] and MEY [mean bias = 82 (465) and 129 (450) Mcal] for progeny 2 and 3, respectively. Observed and predicted progeny feed intake were not correlated. Observed and predicted biological efficiency were positively correlated (0.63 and 0.61) for progeny 2 and 3, respectively. In conclusion, nutrition models can reasonably predict biological efficiency, but further refinement of the relationship between calf feed intake and milk yield could improve prediction.
159 Evaluation of Bacillus Subtilis PB6 Probiotic (CLOSTAT® 500) on Feedlot Phase Growth Performance, Efficiency of Dietary Net Energy Utilization, and Fecal and Subiliac Lymph Node Salmonella Prevalence
Authors: Smith Zachary K , Broadway Paul Rand R , Underwood Keith , Rusche Warren C , Walker Julie , Sanchez Nicole C Burdick , Carroll Jeffrey A , Lafleur Doug , Hergenreder Jerilyn
Published: May 2021

Yearling beef steers (n = 238; initial BW=402 ± 31.2 kg) were used to evaluate a Bacillus subtilis probiotic on growth performance, dietary net energy (NE) utilization, carcass characteristics, and fecal and subiliac lymph node Salmonella prevalence during a 140-d finishing period. Steers were allotted to 24 pens (n = 9 to 10 steers/pen) and assigned to one of two treatments (12 pens/treatment): no probiotic (CON) or 0.50 g·steer-1·d-1 of a Bacillus subtilis PB6 probiotic (CLOSTAT® 500, Kemin Industries, Des Moines, IA; CLO). Steers were transitioned to a 90% concentrate diet (DM basis) over 14-d. Steers were fed once daily at 0700 h; bunks were managed according to a slick bunk management. Fecal samples were collected on d 1, 28, 56, 112, and 140 from each pen (n = 5 steers/pen) via rectal palpation and composited by pen for determination of Salmonella prevalence. Upon harvest, subiliac lymph nodes were obtained from 60 steers in CON and 57 steers in CLO. Data were analyzed as a randomized complete block design; pen was the experimental unit; α of 0.05 determined significance. No differences were detected (P ≥ 0.25) between treatments for live or carcass-adjusted average daily gain, dry matter intake, gain efficiency, dietary NE utilization, nor calculated dietary NE content based upon performance. No differences were detected between treatments for any carcass traits (P ≥ 0.15). Salmonella was not recovered in any fecal samples except on d 112, where steers from CLO had a numerically lower (P = 0.17; 8.3 vs. 25.0%) incidence of fecal Salmonella compared to CON and on d 140 fecal, where Salmonella incidence did not differ (P = 0.34; 0.0 vs. 8.3%) for CON and CLO, respectively. Salmonella was not recovered in any subiliac lymph nodes. These data indicate that CLO did not influence growth performance or Salmonella prevalence.