bluuebunny/crossref_metadata_2025 huggingface dataset:
191 Recovery of Growth and Body Composition in 10-kg Pigs after a 6-Week Growth Attenuation by Ammonium Chloride Additions to Feed
Authors: Kokinos Brittney P , Budde Rachel A , Capdeville Mariola Grez , Amundson Laura A , Stevens Andrew W , Chavas Jean-Paul , Crenshaw Thomas D
Published: October 2023

This project aimed to develop nutritional strategies to reduce pig growth > 50% for 2 to 6 weeks during crisis management. Previously growth was attenuated by 2.0% NH4Cl additions to hold growth (HG) diets. Compensatory growth was evident after withdrawal of NH4Cl. However, tissue composition was not quantified. The HG diets were formulated to reduce lysine, P, and K and increase Cl. Assumptions were that excess Cl interacts with limited K to create an “apparent” K deficiency, which limits protein accretion. The current experiment assessed body composition responses during recovery from HG diets with 2.0% NH4Cl (HGCL) by feeding control (Ctl) diets or Ctl diets fortified with 150% of lysine, P, and K requirements (+Lys+P+K). At 10 kg, 34 barrows were individually housed and randomly assigned to 1 of 4 dietary treatments with free access to assigned diets and water throughout the trial. During the HG phase pigs were fed either Ctl or HGCL diets until 25 kg; 6 weeks for pigs fed HGCl diets. An additional diet was included to validate K and Cl interactions (0.29:1 K:Cl ratio) in growth attenuation. Potassium bicarbonate was added to the HGCl diet (HGCl+K) to restore a 1.26:1 K:Cl ratio. At 25 kg BW, pigs were fed either Ctl or +Lys+P+K diets until 45 kg body weight (BW). Pig, feed weights, and body composition derived from whole-body DXA scans during the hold (HG, 10 to 25 kg) and recovery (Rec, 25 to 45 kg) phases allowed calculations of BW gain, nutrient intake, and measurements of whole-body bone mineral, fat, and lean gain. Growth of pigs fed HGCl diets was reduced (P < 0.01) by approximately 50% compared with Ctl pigs during the HG phase (Table 1). Pigs fed HGCl diets required 23 more days to grow from 10 to 25 kg. Similar reductions (P < 0.01) in bone mineral and lean gain, but not fat gain, were detected in pigs fed HGCl diets during the HG phase. Addition of K to the HGCl diet partially restored gain, bone, and lean gain (P < 0.01). Compensatory responses in weight, bone, fat, and lean gain were evident in HG pigs fed Ctl diets during Rec. Pigs previously fed HGCl diets compensated and only required 14 extra days to reach 45 kg compared with Ctl. Additions of lysine, P, and K allowed greater (P < 0.01) compensation in BW, bone, and lean, but not fat gain over a 20 kg recovery phase. These results confirm a successful strategy to hold pigs during crisis management with potential benefits of compensatory growth and improved body composition during recovery. Whether the improved lean gain was attributed to the additional lysine, P, or K was not determined in this experiment.
268 Heat Stress Impacts on Cattle Production
Authors: Baumgard Lance H , Rhoads Robert P
Published: October 2023

Heat stress (HS) compromises farm animal productivity and it is thus both an economic and food security issue. Reduced output (e.g., milk yield, muscle growth, egg production) during HS was traditionally thought to result from decreased nutrient intake (a classic biological response shared by all animals during environmental-induced hyperthermia). Utilizing pair-feeding experimental designs clearly indicate that reduced feed intake only accounts for a portion of the decreased productivity. The etiological epicenter of many (if not most) of the physiological consequences of HS is gastrointestinal tract hyperpermeability. For reasons not clearly understood, HS compromises the intestinal barrier allowing luminal antigens to infiltrate into local and systemic circulation. The invading antigens are recognized and stimulate the immune system. An activated immune system rearranges the hierarchy of nutrient partitioning, and the entire body participates in ensuring that leukocytes receive the fuel and building blocks necessary to mount an effective response. Central to this is increased insulin secretion coupled with simultaneous decreased adipose tissue and skeletal muscle insulin resistance. Activated leukocytes switch their energetic metabolism away from oxidative phosphorylation to aerobic glycolysis. Utilizing a LPS-Euglycemic clamp we have estimated that an intensely activated immune system can use more than 2 kg of glucose/d in lactating cows. We extended this in growing steers and pigs and the amount of glucose used is approximately 1 g/Kg BW0.75/h regardless of species and physiological state. If the heat load is severe enough, the consequences can become lethal. This is primarily explained by inflammation induced hypercoagulation, endothelial barrier dysfunction and disseminated intravascular coagulation. If the animal survives, these changes result in the reprioritization of fuel selection during HS which appears to be primarily responsible for reduced animal productivity during the warm summer months.
2 Metagenomic Detection and Binning of Plasmids for an Improved Understanding of the Risk of Antimicrobial Resistance Gene Transfer Events
Authors: Anderson Christopher L
Published: October 2023

Multidrug-resistant bacteria are on the increase and threaten human and animal health. Livestock commensal bacteria are a reservoir of antimicrobial resistance genes that can transmit to foodborne pathogens via plasmids and other mobile genetic elements. Assessing the relative risk of resistance genes in a culture-independent manner is a critical goal of antimicrobial resistance surveillance; however, determining the genomic context of a resistance gene remains difficult as mobile genetic elements often fail to assemble and bin accurately in metagenomic studies. To address this issue and better understand the transmission of antimicrobial resistance genes, we developed a machine learning classifier to identify plasmid genomic segments in metagenomic and long-read datasets. We further demonstrate that our plasmid classifier can be applied to identify plasmid bins with low contamination following metagenomic binning. Our findings highlight that metagenomic binning combined with accurate plasmid classification can better resolve the genomic context of antimicrobial resistance genes in culture-independent studies. Lastly, we successfully applied our plasmid prediction tool with droplet digital PCR to determine the absolute abundance of plasmid-encoded antimicrobial resistance genes in bacterial populations. Overall, we demonstrate how our machine learning approach for classifying plasmids can improve the surveillance of mobile antimicrobial resistance genes over current quasi-metagenomic approaches based on culture enrichments. In the future, this research can be extended to predict and better understand the risk of antimicrobial resistance gene transmission in animal agriculture environments.
116 Effect of Crude Protein Level and a Fermentation Product on Sow Reproductive and Piglet Performance
Authors: Hu Qiong , Zhao Junmei , Paton Neil , Walston Stephanie , Legall Maud , Newcomb Mark
Published: October 2023

High crude protein (CP, greater than 16%) has traditionally been used in lactating sow diet for milk production. However, excess protein can lead to increased gut permeability and inflammation, resulting in compromised reproductive performance. It was hypothesized that decreased dietary CP, using a fermentation product (FER) or addition of Zinc in the lactation diet would promote better gut health and improve sow reproductive performance. The present study was a randomized block design with 5 treatments, 4 of which formed a 2 x 2 factorial arrangement. Gestating sows (n = 550) were enrolled with entry body weight of 209.1 ± 11.4 kg and allotted to one of the following five diets: high CP, no FER; high CP, FER; low CP, no FER; low CP, FER; high CP, ZnSO4 diet. Corn-soy based lactation diet was formulated with high (17.5%) and low (14.5%) CP and with or without FER. High CP with ZnSO4 (360 ppm) was used as a positive control and the added Zn level in the other diets was kept at 120 ppm. All diets were formulated to be at similar net energy and standardized ileal digestible (SID) Lysine (Lys) level with balanced essential amino acid to Lys ratio, except SID isoleucine/Lys was greater in high CP diets. Experimental diets were fed beginning approximately 4 days before farrowing and throughout the entire lactation phase (21 days). Using R, performance data were analyzed using a general linear model and a generalized linear model specifying a binomial distribution was deployed for count data. In summary, dietary treatment did not impact average daily feed intake. Low CP diet resulted in lighter sow weaning weight compared with high CP diet (P < 0.01) and tended to increase piglet average weaning weight (P < 0.10) regardless of FER inclusion. Dietary treatment did not affect the probability of still born or number of weaned pigs. There was an interaction (P < 0.05) between CP and FER on probability of born alive, with low CP, FER diet numerically having greatest probability of born alive. Both low CP (P < 0.10) and high CP with ZnSO4 (P < 0.10) tended to increase livability compared with high CP diet treatment, respectively. High CP with ZnSO4 treatment decreased pre-weaning mortality as compared with high CP treatments (P < 0.05). Conclusively, lower dietary CP led to better reproductive performance in sows and greater piglet weaning weight. The fermentation product did not impact sow or piglet performance as hypothesized, and ZnSO4 used at moderate level in high CP diet reduced pre-weaning mortality.
118 Estimating the Net Energy Requirement of Piglets During the First Three Weeks Post-Weaning
Authors: Wellington Michael O , Hulshof Tetske G , Camats Lluís Fabà , Van Hees Hubèrt
Published: October 2023

Previous work has reported that piglets may be unable to increase feed intake to meet energy demands in low-energy diets, contrary to growing pigs. Indeed, poor feed intake in piglets occurs mainly during the first three weeks post-weaning. The approach, in this case, has been to increase the energy density of weaner diets to meet energy requirements even at reduced intakes. Studies estimating the net energy (NE) requirement in piglets in the immediate post-weaning period are lacking. Hence the objective of the present study was to evaluate the dietary NE required to optimize growth and feed efficiency in piglets during the first 21 d post-weaning. A total of 360 mixed-sex piglets (6.4 ± 0.24 kg) were housed with three pigs/pen and 24 pens/treatment (n = 24 pens) and were assigned to 1 of 5 dietary treatments in a dose-response arrangement for 21-d. The experimental diets were formulated to contain graded dietary NE levels (2,200, 2,300, 2,400, 2,500, and 2,600 kcal NE/kg). Diets were isonitrogenous and balanced for amino acids with a constant SID Lys/NE ratio of 1.25 across the treatments. The orthogonal polynomial contrast statement was used in a GLM model (PROC GLM, SAS studio) to determine the linear and quadratic effects of increasing dietary NE level on performance parameters. Results for the overall 21-d period indicated that, as dietary NE increased, average daily gain (ADG) increased linearly (P = 0.03). The average daily feed intake (ADFI) was not significantly (P = 0.157) affected by increasing dietary NE. The gain to feed (G:F) improved linearly as dietary NE increased (P = 0.008). Using the linear-breakpoint model (PROC NLIN), the NE estimated to maximize ADG at 305 g/day was 2,475 kcal NE/kg (P = 0.008). Similarly, for maximum G:F of 0.86 g/g, the linear breakpoint model estimated the NE requirement at 2460 kcal/kg (P = 0.02). No breakpoint was estimated for ADFI, but the model tended (P = 0.08) to show a linear increase in ADFI as NE increased. In summary, the results of this study highlight that, during the first three weeks post-weaning, feed intake of piglets may be more controlled by animal factors (e.g., gut capacity) and, to a lesser extent, energy concentration because feed intake was not affected by the dietary NE level in this study. Further, results show that ADG may be a more accurate measure of the impact of NE concentration than ADFI. In conclusion, dietary NE levels between 2,460 to 2,475 kcal/kg during the first three weeks post-weaning may be ideal to maximize growth performance, provided all other nutrients are not limiting.
123 Effects of Different Protein Sources Containing Highly Digestible Phosphorus on the Basal Endogenous Loss of Phosphorus
Authors: Nelson Megan E , Lee Su A , Stein Hans H
Published: October 2023

The objective of this experiment was to test the hypothesis that the basal endogenous loss of P from pigs fed a diet containing blood plasma, casein, or potato protein concentrate is not different from that of pigs fed a diet containing gelatin. Pigs (n = 40; body weigh =: 19.34 kg) were housed in metabolism crates and were randomly allotted to four low-P diets containing 20% gelatin, 20% blood plasma, 18.5% casein, or 20% potato protein concentrate. With the exception of Ca and P, diets were formulated to meet the requirements for 11 to 25 kg pigs. Feces and urine samples were collected separately for 4 d following a 5-d adaptation period. Feces samples were dried, ground, and analyzed for Ca and P, and urine samples were also analyzed for Ca and P. Data were analyzed using a model that included diet as fixed effect and replicate as random effect. Results indicated that feed intake and fecal excretion of dry matter were greater (P < 0.05) in pigs fed diets containing blood plasma, casein, and potato protein concentrate compared with pigs fed the gelatin diet, with pigs fed potato protein concentrate having the greatest (P < 0.05) excretion (Table 1). The apparent total tract digestibility of dry matter was least (P < 0.001) in pigs fed the diet containing potato protein concentrate, but there were no differences among gelatin, blood plasma, and casein diets. No differences were observed in the standardized total tract digestibility of P among diets. Basal endogenous loss of P was not different between the gelatin and casein diets, but pigs fed diets containing blood plasma or potato protein concentrate had greater (P < 0.001) basal endogenous loss of P compared with pigs fed gelatin or casein diets. In conclusion, the basal endogenous loss of P was greater in diets containing blood plasma and potato protein concentrate compared with gelatin. However, casein could be an alternative to gelatin to estimate the basal endogenous loss of P because casein provides a greater amount of P compared with gelatin that compensates for the deficient level of P in gelatin, but does not affect values for the basal endogenous loss of P.
126 Effects of Soy Hulls and Sugar Beet Pulp on Growth Performance of Nursery Pigs
Authors: Cemin Henrique S , Hart Morgan D , Pietig Jamie L , Hansen Sharlie A , Soto Jose A , Hansen Ernie L
Published: October 2023

An experiment was conducted to determine the interactive effects of soy hulls (SH) and sugar beet pulp (SBP) on growth performance of nursery pigs. A total of 2,448 mixed sex pigs (initial BW = 6.3 kg), placed in pens of 36 pigs each, were used in a 40-d trial. Treatments were arranged in a 2 × 3 factorial with two levels of SBP (0 or 5%) and 3 levels of SH (0, 3.75, or 7.5%) with 11 replicates per treatment. Corn and a fermented soybean meal product (ME-Pro, Prairie AquaTech, Brookings, SD) were replaced by the fiber sources to achieve the desired fiber concentration, whereas soybean meal inclusion rate was held constant across treatments. Diets were not balanced for net energy. Experimental diets were fed from d 0 to 18 and a common corn-soybean meal-based diet was fed from d 18 to 40. Pigs were weighed on d 0, 18, and 40 to calculate ADG, ADFI, and G:F (Table 1). Data were analyzed with the MIXED procedure in SAS. From d 0 to 18, there was a SH × SBP interaction for ADG (P = 0.016) and ADFI (P = 0.023). Pigs fed diets with the highest inclusion of SH without SBP had increased ADG and ADFI; however, pigs fed diets containing SBP had improved performance up to 3.75% SH inclusion, and decreased ADG and ADFI with the highest SH inclusion. From d 18 to 40 and overall (d 0 to 40), there was an interaction (P ≤ 0.007) for G:F, where pigs fed diets containing 3.75% SH without SBP had improved G:F, while pigs fed diets with 3.75% SH containing SBP had worsened G:F. In summary, these results suggest that both fiber sources can be safely fed to nursery pigs, although the interactive effects must be considered when determining inclusion rates.
134 Meta-Analysis to Determine the Standardized Ileal Digestible Lysine Requirements of Growing-Finishing Pigs from 11- to 150-kg Utilizing the Ingredients Database of Inra
Authors: Montoro Jordi Camp , Casserly Ronan , Vier Carine M , Navales Ron A , Cast Wayne R , Lu Ning , Dritz Steve , Orlando Uislei A
Published: October 2023

A meta-analysis was conducted to determine the standardized ileal digestible (SID) lysine (Lys) recommendations for 11–150 kg PIC pigs housed under commercial conditions utilizing the INRA feed ingredients database. Data from 29 trials dating from 2013 to 2020 utilizing 48,338 pigs were recorded in a database. Number of pens/treatment and pigs/pen ranged from 9 to 16 and 12 to 25, respectively. Sire lines were PIC 337 in 25 trials, PIC 327 in 3 trials, and PIC TR4 and 327 in 1 trial. Dam lines were PIC Camborough in 18 trials and PIC Camborough 29 in 9 trials. The SID Lys levels reported in each trial were used, and the SID Lys to calorie ratio curves were built for both metabolizable energy (ME) and net energy (NE) systems using the feed ingredient composition in INRA for energy levels. The response variables, average daily gain (ADG) and feed efficiency (G:F), were analyzed within 7 phases using generalized linear and non-linear mixed models with heterogeneous variance (Gonçalves et al., 2016). Phases consisted of the following body weight ranges: 11-23, 23-41, 41-59, 59-77, 77-104, 104-127, and 127-150 kg . Each treatment mean within a trial (n = 288) was considered the experimental unit and each trial was used as a random effect. There was no evidence for an interaction between sire lines or dam lines and treatment (P > 0.10). The SID Lys to calorie recommendations are based on the average of the requirement estimates for ADG and G:F. At these levels, approximately 100% of maximum ADG and 99.7% of maximum G:F are achieved. After determining the requirement estimates within each of the 7 weight breaks, a quadratic equation of Lys to calorie ratio was fit for each energy system. The equations are described as: g of SID Lys:Mcal of ME = 0.0001381709 × (weight, kg)2 - 0.0366272129 × (weight, kg) + 4.6073086522; and g of SID Lys:Mcal of NE = 0.0000400092 × (weight, kg)2 - 0.0235648387 × (weight, kg) + 6.2762350341. These data provide the estimated SID Lys requirements for maximal growth performance for PIC pigs from 11- to 150-kg based on the ingredients database of INRA.
135 Effects of Increasing Dietary Standardized Ileal Digestible Lysine Levels on Growth Performance of PIC 337 × Camborough Commercial Pigs that were Sired by High Index Boars
Authors: Lu Ning , Parr Eric , Estrada Jorge , Vier Carine M , Diaz Julia A Calderon , Welsch Michael , Cast Wayne R , Navales Ron A , Montoro Jordi Camp , Zaragoza Luis E , Dritz Steve , Orlando Uislei A
Published: October 2023

Our objective was to determine the effects of increasing dietary standardized ileal digestible lysine levels on the growth performance of PIC 337 × Camborough commercial pigs that were sired by high-index boars. A total of 2,200 barrows and gilts (PIC 337 × Camborough) were used in six experiments covering body weight ranges of 11-25 kg (Exp.1), 26-46 kg (Exp.2), 45-66 kg (Exp.3), 63-85 kg (Exp.4), 86-110 kg (Exp.5), and 108-134 kg (Exp.6). Pigs were placed in two rooms with 45 pens in Room 1 and 43 pens in Room 2, and there were 25 pigs/pen (12 or 13 gilts and 13 or 12 barrows) for both rooms. Room 1 was used in Exp. 1, 3, and 5; Room 2 was used in Exp. 2, 4, and 6. At the beginning of each trial, on-test pens were blocked by body weight and randomly allotted to one of five treatments (90, 100, 105, 110, or 120% of PIC SID Lys recommendations for Exp.1 to Exp. 5; whereas 80, 90, 100, 110, or 120% of PIC SID Lys recommendations for Exp. 6) in a randomized complete block design. Off-test pens were fed a common wash-out diet between trials, and common diets were formulated to meet PIC nutrient requirements according to the specific weight range. Data were analyzed using generalized linear mixed model with pen as the experimental unit in R Studio (Version 3.5.2, R Core Team; Vienna, Austria). Dietary SID Lys levels were included as fixed effects, and weight block was included as random effects in the model. All data are reported as least square means and considered statistically significant at P < 0.05 and marginally significant at P < 0.10. Increasing SID Lys improved average daily gain (ADG; linear, P = 0.003) and gain-to-feed ratio (G:F; quadratic, P = 0.007) in Exp.1; improved ADG (quadratic, P = 0.045) in Exp.4; improved ADG (quadratic, P = 0.009) and G:F (quadratic, P = 0.002) in Exp.5; and improved ADG (linear, P = 0.037) and G:F (linear, P = 0.030) in Exp.6 (Table 1). However, there was no evidence for difference among treatments on growth performance in Exp.2 and 3. With increasing dietary SID Lys levels, gram of SID Lys per kilogram of bodyweight gain increased in a quadratic manner in Exp.1 (P = 0.025) and 5 (P = 0.002); and increased in a linear manner in Exp.2, 3, 4, and 6 (P < 0.001). In conclusion, increasing dietary SID Lys levels improved the growth performance of PIC 337 × Camborough commercial pigs sired by high-index boars when the bodyweight was below 25 kg or beyond 63 kg.
129 Effects of Standardized Ileal Digestible Lysine on Growth Performance of 12- to 136-kg PIC Line 800-Sired Pigs
Authors: Gaffield Katelyn , Tokach Mike D , Woodworth Jason C , DeRouchey Joel M , Goodband Robert D , Gebhardt Jordan T , Vier Carine M , Spindler Matthew , Orlando Uislei A , Zaragoza Luis E , Lu Ning , Cast Wayne R , Wilson-Wells Danielle , Holen Julia , Betlach Alyssa
Published: October 2023

The objective of this study was to evaluate growth performance and economic return of PIC 800 × Camborough pigs fed increasing SID Lys from approximately 12- to 136-kg. Pens of pigs were blocked by body weight (BW) and randomly assigned to 1 of 5 dietary treatments in a randomized complete block design with 26 pigs per pen and 16 pens per treatment. Pens were provided 1 of 5 dietary treatments with increasing SID Lys at 85, 93, 100, 107, and 115% of current (2021) PIC recommendations within 6 dietary phases as follows: phase 1 (1.09, 1.19, 1.28, 1.36, and 1.47%), phase 2 (0.97, 1.06, 1.14, 1.22, and 1.32%), phase 3 (0.87, 0.95, 1.02, 1.09, and 1.17%), phase 4 (0.75, 0.82, 0.88, 0.94, and 1.01%), phase 5 (0.66, 0.72, 0.77, 0.82, and 0.89%), and phase 6 (0.59, 0.64, 0.69, 0.74, and 0.79%). Two corn-soybean meal-based diets containing low and high Lys were blended to achieve target SID Lys levels for each treatment diet within phase. Overall (d 0 to 143), increasing SID Lys improved (linear, P ≤ 0.007) ADG and G:F, but did not impact ADFI (P > 0.10; Table). A tendency (linear, P = 0.067) for heavier hot carcass weights (HCW) was observed in pigs fed increasing SID Lys. However, there was no evidence for differences (P > 0.10) in carcass yield, backfat depth, loin depth, or carcass lean percentage across treatments. The linear (LM) model served as the best fit for both growth and economic parameters. The LM model predicted maximum ADG and G:F at levels greater than 115% of PIC’s current recommendations. However, for income over feed cost (IOFC), the LM model predicted maximum profitability at or below 85% of the current Lys recommendations of PIC. In conclusion, the optimal SID Lys level for PIC 800 × Camborough pigs from 12- to 136- kg differed upon response criteria, with growth performance maximized at levels at or above 115% of the recommendation for SID Lys by PIC; however, maximal economic returns were observed at or below 85% of PIC’s current SID Lys recommendations.
130 Effects of Increasing Dietary Standardized Ileal Digestible Lysine Levels on Growth Performance of 102- to 127-kg Immunocastred Gilts and Boars
Authors: Lima Gustavo , Castro Gabriel , Ribeiro Neidilania , Silva Analia , Vier Carine M , Siqueira Amanda P , Orlando Uislei A , da Silva Caio A
Published: October 2023

Our objective was to determine the effects of increasing dietary standardized ileal digestible (SID) lysine (Lys) on growth performance of immunocastrated gilts and boars. A total of 3,519 split gender pigs [PIC 337×Camborough, initial body weight (BW) = 101.7 ± 3.89 kg] were used in a 21-d trial in 2 replicates. Following the immunization against gonadotropin-releasing hormone (administrated with Vivax, Zoetis, São Paulo, SP, Brazil) in both genders, pens of pigs were weighed, blocked by BW, and randomly allotted to 1 of 5 treatments. Treatments consisted of 1.69, 1.90, 2.11, 2.32, and 2.53 g of SID Lys:Mcal of ME, which corresponded to 80, 90, 100, 110, and 120% of PIC SID Lys recommendations for mixed gender between barrow and gilts. This resulted in 0.56, 0.63, 0.70, 0.77, and 0.84% SID Lys given that the treatment diets were corn-soybean-meal-based and contained 3,300 Kcal of ME/kg. There were 6 split gender pens∙treatment-1∙replicate-1 and 29 pigs/pen. Data were analyzed using generalized linear and nonlinear mixed models with a pen as the experimental unit. Competing models included linear, quadratic polynomial (QP), broken-line linear (BLL), and broken-line quadratic (BLQ). There was no evidence of linear or quadratic SID Lys concentration by gender interaction (Table). Increasing SID Lys concentration improved average daily gain (ADG; quadratic, P < 0.01) and gain-to-feed ratio (G:F; quadratic, P < 0.01). The QP, BLL, and BLQ had a similar fit for the ADG and G:F. In the QP model, 95% and 100% of the ADG were achieved at 0.64 and 0.76% of SID Lys, respectively, and at 0.61 and 0.75% for G:F. The BLL and BLQ models estimated the breakpoint at 0.70% (95% CI: 0.65-0.74%) and 0.68% SID Lys (95% CI: 0.50-0.85%), for ADG, respectively. For G:F, the BLL, and BLQ models estimated the breakpoint at dietary SID Lys of 0.69% (95% CI: 0.52-0.86%) and 0.68% (95% CI: 0.58-0.78%), respectively. There was no evidence that increasing dietary SID Lys levels impacted the average daily feed intake or the removal and mortality rate. In the current trial the estimated optimum SID Lys:Mcal of ME ratio for 102- to 127-kg immunocastrated gilts and boars ranged from 2.06-2.30 (0.68-0.76% SID Lys based on a 3,300 kcal of ME/kg diet), depending on the statistical model.
128 Lysine Titration for Intact Males and Gilts During the Grower-Finisher Period in Both Summer and Winter Seasons in a South African Commercial Production System
Authors: Steyn Willem J , Bradley Casey L , Pennicott Chantel , Raath Jaco J , Van Deventer Myles
Published: October 2023

The decision as to the optimum amount of dietary balanced protein to feed to commercial grower-finisher pigs should be based on both biology and economics. Terminal sired genotypes are constantly changing due to the selection pressures applied by geneticists on the patrilineal as well as matrilineal animals, as are the relative costs of protein-containing ingredients and the revenue derived from the sale of pork. Thus, the objective of this study was to determine the most efficacy and economical levels of lysine to feed grower finisher swine in both the summer and winter seasons in South Africa. The trial was conducted at the Baynesfield Swine Research Unit at Baynsefield Estate in KwaZulu Natal, South Africa. A total of 528 animals (26.48 ± 0.33 kg initial BW, TN 70 Topig genetics, 70-d of age) were used in an 84-day study, consisting of the grower-finisher period. The house consists of 48 pens each containing 11 pigs with a total of 528 pigs in the house. Pens were randomly allocated to one of six treatments (n = 8 pens). Each diet by phase was formulated with the same NE but with different SID Lys levels (120%, 110%, 100%, 90%, 80%, 70%) of the Topigs Norsvin Tempo Progeny Grower feed manual. All the diets were fed in a four-phase program. Individual body weight and pen feed intake were taken at each phase change. Data was analyzed utilizing Prox MIX (SAS, 2021). Pigs had ad libitum access to feed and water. Feed intake and body eight were measured at every phase change. Additionally, the carcass variables of percent lean, grade, cold carcass weight, and yield were measured at slaughter. The economic variables of feed cost, carcass value, mofc, and cost per gain were calculated to make a comparison. Statistical analysis was conducted in SAS (2021) utilizing the Proc GLM model for the average effects within each period and connection letter calculated with Fisher’s test. Yield and grade were optimized when pigs were fed the 100% SID Lysine diet. Pigs fed the 120% SID Lysine diet had the best overall gain and slaughter BW in both seasons (Table 1). Pigs that were fed the 120% SID Lys diet had the greatest average daily gain when compared with other treatments for the winter trial but during the summer trial the pigs that were fed the 100% SID Lys diets showed the greatest average daily gain. However, the greatest margin over feed cost during both summer and winter was obtained from the 90% SID lysine treatment. In conclusion, raw ingredient costs and seasonality are critical components when optimizing SID lysine for more than just gain but profitability.
146 Efficacy of Zinc Glycinate Reducing Zinc Oxide on Growth and Intestinal Health of Nursery Pigs Challenged with F18+Escherichia Coli
Authors: Jang Ki Beom , Moita Vitor Hugo C , Martinez Nicolas , Sokale Adebayo O , Kim Sung Woo
Published: October 2023

The objective of this study was to investigate the effect of ZnGly supplementation reducing ZnO in feeds on growth performance and intestinal health of nursery pigs challenged with F18+Escherichia coli (E. coli). A total of 56 nursery pigs (initial BW = 6.5 ± 0.5 kg) were allotted to 7 treatments based on a randomized complete block design using BW and sex as blocks. Treatment groups were: 1) NC: no-challenged with E. coli; 2) PC: challenged with F18+E. coli; 3) challenged with F18+ E. coli and fed ZnO at 2,500 mg/kg in the diet; (4 to 7) challenged with F18+E. coli and fed ZnGly at 400 mg/kg and ZnO at 0, 700, 1,400, and 2,357 mg/kg in the diets. Pigs were fed for 28 days based on 2 phases (Phase 1: 14 d and phase 2: 14 d) and 48 pigs were orally inoculated with F18+ E. coli (6 × 109 CFU/mL) on d 7. Pigs were euthanized on d 28 to collect tissues to evaluate TNF-α, IL-8, malondialdehyde, protein carbonyl, gene expression of Zn transporters, and mucosa-associated microbiota in the jejunum. Data were analyzed by Mixed procedure of SAS. The E. coli challenge tended to decrease (P = 0.076) ADG (200 to 155 g/d) and (P = 0.055) G:F (0.82 to 0.69) during phase 1, and increased (P < 0.05) fecal score (3.2 to 4.1) of nursery pigs during d 7 to 14. There was no difference on the growth performance during the overall period, although pigs fed with the pharmaceutical level of ZnO had greater (P < 0.05) ADG (343 vs. 256 g/d) than pigs fed with ZnGly at 400 mg/kg during the first week of post-challenge. Supplementation of ZnGly with reducing the levels of ZnO from 2,357 to 0 mg/kg tended to have a quadratic response on the fecal score (maximum 4.2 at 667 mg/kg of ZnO) during post-challenge period. Supplementation of ZnGly with reducing levels of ZnO from 2,357 to 0 mg/kg linearly decreased (P < 0.05) IL-8 (0.94 to 0.58 ng/mg) and malondialdehyde (0.49 to 0.34 μM/mg) in jejunum of the pigs. Supplementation of ZnGly reducing the levels of ZnO from 2,357 to 0 mg/kg linearly increased (P < 0.05) Chao1 (142.2 to 148.7) and decreased (P < 0.05) Shannon (4.08 to 3.99) with quadratic effects (P < 0.05) on relative abundance of Pseudomonadaceae (minimum 6.15% at 1,000 mg/kg) and Streptomycetaceae (minimum 5.91% at 800 mg/kg) at family level in jejunum of the pigs. In conclusion, ZnGly supplementation at 400 mg/kg could effectively reduce the use of ZnO in nursery feeds by having similar effects to the pharmaceutical use of ZnO without negatively affecting growth performance and intestinal health of pigs challenged with F18+E. coli.
137 Macroalgae Extracts Limits Marek’s Disease Virus Load and Dissemination in Vitro
Authors: Rodriguez Maria A
Published: October 2023

Marek’s disease (MD) is a highly contagious lymphoproliferative disease of chickens caused by an alphaherpesvirus, Marek’s disease virus (MDV). Marek’s disease is presently controlled by systematic vaccination of animals, which protects efficiently against clinical disease, However, MDV vaccines do not prevent the multiplication and spread of MDV field strains generating immunosuppression. They may also favor the emergence of strains with increased virulence. Therefore, MDV persists to be a major problem for the poultry industry generating economic losses estimated at 1 to 2 billion dollars per year. The development of new sustainable alternative strategies to control MDV is needed. Macroalgae extracts have previously been shown to exert antiviral and immunomodulatory activities that could support the animals to better resist to this challenge. The objective of the study was to explore the effect of sulphated green macroalgae (Ulva.sp) extract (MSPIMMUNITY) on MDV infection in vitro. To determine the impact on MDV lytic replication, CEFs were infected and treated with increasing doses of algae extract. The viral load was quantified at 24, 48, 72, and 96 hours post infection (hpi) by qPCR. The results showed the treatments significantly decreased MDV lytic replication in CEFs in a dose-dependent manner with the strongest effect observed with concentrations of 1mL/L. From 24 hpi, the viral load was reduced by about 80% with the algae extract at a concentration of 2mL/L and this is maintained over time and reached 94% at 96 hpi, A substantial decrease in MDV plaque size (from 2- to 3-fold) was demonstrated suggesting that macroalgae extract impede MDV cell-to-cell spread in vitro. This study provides the first evidence that the use of macroalgae extracts could be a good alternative to limit MDV infection in poultry. It could be used in in feed or in drinking water formulation to support the fight of the animal to viral challenges.
143 Awardee Talk: Improving Nursery pig Growth Performance with Supplemented Tryptophan in a Vaccine-Induced Immune Challenge
Authors: Brizgys Lauren A , Richert Jacob A , Scaff Taw , Richert Brian T , Radcliffe John Scott
Published: October 2023

Weaning pigs is often concurrent with transportation-induced stress which can impair growth performance, feed efficiency, and immune resilience, contributing to reduced welfare and increased production losses. The objective of this experiment was to mitigate the adverse effects of early life transport stress on subsequent immune challenges by providing supplemental tryptophan (Trp) during the nursery period. A total of 384 pigs were transported for 8 h at weaning and used in a randomized complete block design with a 2x2 factorial arrangement of immune challenge (Vaccine challenged vs. Unvaccinated) and dietary treatment (Supplemented Trp vs. Non-supplemented Trp). Pigs were fed standard nursery diets, in four phases, over 35-d with pigs receiving 1X or 2X the NRC (2012) recommended Trp concentration. There were 12 pens/treatment with 8 pigs/pen (5 barrows and 3 gilts). Individual BW and pen feed intakes were determined weekly. One-half the pigs on each dietary treatment were subjected to a 3-wk vaccine challenge consisting of Mycoplasma (Respisure-One), Influenza (Flusure XP), and Ileitis (Porcilis) vaccines administered in week 2, 3, and 4 post-weaning, respectively. Data were analyzed as a RCB using GLM procedure in SAS 9.4 with fixed effects of dietary treatment and immune challenge, the interactions, and random effect of replicate. Beginning on d 7 and continuing throughout the nursery period, pigs fed diets containing 2X NRC (2012) Trp were heavier (P < 0.05) than pigs fed diets containing 1X Trp. Heavier BW were the result of an overall improvement in ADG for 2X Trp fed pigs (P < 0.006). There was a tendency (P < 0.08) for an interaction of dietary Trp concentration and vaccine challenge on overall ADFI, with added Trp increasing ADFI in pigs not undergoing a vaccine challenge but having no effect in vaccine challenged pigs. During week 4 post-weaning, G:F was less (P < 0.04) for vaccinated pigs compared with unvaccinated pigs. An interaction between dietary Trp and immune challenge was observed in week 5 post-challenge for G:F (P=0.0372) with G:F being reduced in vaccinated pigs fed 1X Trp, but not in vaccinated pigs fed 2X Trp; indicating that supplemental Trp may have added value in immune challenged pigs. Overall, increasing dietary Trp in nursery diets to 2X the NRC (2012) recommendation improves ADG in nursery pigs and maintains feed efficiency during a vaccine-induced immune challenge.
147 The Impact of Salinomycin and Crude Protein Level on Endemically Enterically Challenged Nursery Pigs
Authors: Nisley Mitchell J , Gabler Nicholas K , Sparks Chris , Burrough Eric R
Published: October 2023

Endemic enteric challenges antagonize nursery pig livability and performance. Recent limitations in the therapeutic control of Coccidia have increased the prevalence of coccidiosis in suckling and nursery piglets. Together with diet structure, intestinal inflammation and function may be compromised. Therefore, our objective was to evaluate the use of the coccidiostat, salinomycin, in conjunction with high (HCP) and low (LCP) dietary crude protein (CP) on performance, survivability, and cocci shedding of nursery pigs. Mixed sex pigs (n = 120; initial body weight = 5.63 ± 1.4) were sourced from a coccidia, rotavirus, and hemolytic Escherichia coli positive sow farm and randomly allotted to single sex pens in a 2x2 factorial design (10 pens/treatment). Pigs were fed either HCP (24%) or LCP (18%) diet with or without salinomycin. All pigs were fed in three phases lasting 9, 12, and 21 days, respectively. Salinomycin was fed in phases 1 and 2 at 90 ppm and in phase 3 at 60 ppm. Pen body weights and feed disappearance were collected at the start and end of each phase to calculate average daily gain (ADG), average daily feed intake (ADFI), and gain to feed ratio (G:F). Fecal consistency was scored for diarrhea presence daily. Within pen, pooled fecal samples were collected on days 9 and 20 for fecal float analysis of Coccidia oocyst counts. On day 9, one pig per pen selected based on median ADG within each pen was euthanized for tissue collection and histopathology assessment. Performance data, mortality/removals, and fecal cocci presence were analyzed for the effects of CP, salinomycin, and their interaction. Pen was the experimental unit and significance was set at P ≤ 0.05. Fecal coccidia oocysts counts were reduced by 85% (P < 0.05) and 80% (P = 0.066) at day 9 and 20, respectively in salinomycin verses control fed pigs. Salinomycin and LCP both decreased diarrhea incidence during phase 2 (P < 0.05). A CP and salinomycin interaction was observed during phase 2 and a tendency was observed overall as salinomycin seemed to mitigate diarrhea presence in HCP pigs (P < 0.05 and P = 0.090). Pigs fed salinomycin had reduced removal rates of 10 and 0%, compared with 15 and 30% for unmedicated LCP and HCP pigs (P < 0.05). No CP by salinomycin interactions for performance metrics were observed. In phase 1, no main effects were observed. During phase 2, LCP tended to increase ADFI for HCP (0.52 vs. 0.44 kg/d, respectively, P = 0.064). During phase 3, salinomycin increased G:F (P < 0.05) and tended to increase ADG (P = 0.080) compared with the control. Overall, 42 day nursery performance was not different between treatments. In conclusion, crude protein did not influence nursery pig performance. However, salinomycin reduced coccidiosis shedding and increased survivability in naturally enterically challenged nursery pigs.
313 Effect of Dietary Trace Mineral Source on Performance, Bones Mineralization and Mineral Status in Fattening Pigs
Authors: Samson Arnaud , Zoon Mieke V , Oguey Clémentine
Published: October 2023

Several papers report greater bioavailability of dietary trace mineral fed as organic in pigs compared with inorganic sources. However, only a few studies have tried to assess the variability of the trace mineral bioavailability among different organic sources. Growing barrows (n = 54; initial BW = 28.9 ± 1.3 kg) were used to determine the effects of trace mineral source on growth performance, bones mineralization and mineral status over the entire fattening period (d0-d73). Pigs were blocked by BW and randomly assigned to supplementation of trace minerals as inorganic (ITM) or one of 2 organic sources (OTM): glycine complex (GLY) or amino acids complex (AA). During the two feeding phases (growing: d0-d35; finishing: d35-d73), the experimental diets were supplemented with 5, 35 and 5 mg/kg of Cu, Zn and Mn, respectively. Pigs were fed restricted all through the experimental period. Feed intake was therefore comparable all through the experimental period for all pigs. Growth performance did not differ among the three experimental groups during the growing phase. However, Feed:Gain ratio measured during the finishing period tended to be affected by the dietary treatments (P=0.10). When grouping the GLY and AA pigs, the Feed:Gain ratio measured from d35 to d73 for the OTM pigs was significantly lower compared with ITM pigs (-0.07, P = 0.03). There was no significant effect of the dietary treatment on plasma trace mineral concentrations and alkaline phosphatase activity measured at day 34. At the end of the growing phase, plasma ceruloplasmin activity tended to be greater for the GLY and AA groups in comparison with the ITM pigs (+6.9%, P = 0.06). The zinc deposition in the proximal phalanx was significantly increased when the trace minerals were offered as organic compared with the group ITM (+10.9%, P = 0.06). Zinc content in the liver was greater for the pigs fed the OTM sources compared with the others (+6.0%, P = 0.10). The quantity of copper deposited in the liver did not differ significantly among the 3 trace mineral sources. This study indicates that the total replacement of inorganic Zn, Cu and Mn by organic sources brings benefits in terms of feed efficiency in fattening pigs. A better bioavailability as suggested by greater deposition levels in bone and liver as well as the increased circulating ceruloplasmin activity could explain the improvement of performance during the finishing period. Regardless of the variable considered, no significant differences were noticed between the two organic trace mineral sources.
245 Effects of Standardized Ileal Digestible Tryptophan to Lysine Ratio on Growth Performance of PIC Line 337-Sired Grow-Finish Pigs
Authors: Royall Rafe Q , Tokach Mike D , Woodworth Jason C , DeRouchey Joel M , Goodband Robert D , Gebhardt Jordan T , Vier Carine M , Spindler Matthew , Orlando Uislei A , Zaragoza Luis E , Lu Ning , Cast Wayne R , Wilson-Wells Danielle , Holen Julia , Betlach Alyssa
Published: October 2023

This study was conducted to estimate the SID Trp:Lys requirement for growth and feed efficiency of PIC 337 × 1050 pigs from approximately 46- to 73-kg. A total of 840 pigs [initial body weight (BW) = 45.9 ± 0.95 kg] were used in a 28-d growth performance study. Pens of pigs were blocked by BW and randomly allotted to dietary treatments with 22 to 27 pigs per pen and 7 replications per treatment in a randomized complete block design. Pens were provided 1 of 5 dietary treatments with increasing SID Trp:Lys ratios at 15, 17.5, 19, 21, and 23%. Two corn-soybean meal-based diets with 30% DDGS containing 15 and 23% Trp:Lys ratios were blended to achieve dietary targets for SID Trp:Lys. Average daily gain, ADFI, G:F, Trp Intake/kg of gain, and final BW increased (quadratic, P ≤ 0.008) with increasing Trp:Lys ratio, while Trp intake/d increased linearly (P < 0.001; Table). Additionally, Lys intake/d increased (quadratic, P = 0.009) while Lys intake/kg of gain decreased (quadratic, P = 0.008). A broken-line linear model predicted no further improvement to ADG beyond 19.5% SID Trp:Lys for 46- to 73-kg pigs. Meanwhile, a broken-line linear model suggested no further improvement to G:F beyond 19.3% SID Trp:Lys, while a similar fitting quadratic polynomial model suggested that maximum G:F was achieved at 21.3% SID Trp:Lys. In summary, these results suggest that the optimal SID Trp:Lys level for 46- to 73-kg pigs is 19.5% for ADG and 19.3 to 21.3% for feed efficiency.
240 Comparing Increasing Tryptophan: Lysine Ratios in Distiller Dried Grains-Based Diets with or without Distiller Dried Grains withdrawal Strategy on Growth and Carcass Performance of Grow-Finish Pigs
Authors: Spinler Mikayla , Tolosa Andres F , Woodworth Jason C , Tokach Mike D , Goodband Robert D , DeRouchey Joel M , Coble Kyle , Gerhart Amanda J , Soto Jose A , Gebhardt Jordan T
Published: October 2023

A total of 6,240 pigs [DNA 600 × PIC 1050; initial body weight (BW) = 22.5 ± 0.20 kg], divided into 2 groups, were used in 119- or 120- day study comparing increasing Trp:Lys ratio in diets with DDGS or a DDGS withdrawal strategy on growth and carcass performance and carcass fat iodine value of grow-finish pigs. Pigs were randomly allotted to 1 of 7 dietary treatments with 30 to 36 pigs per pen and 26 replications per treatment. Diets were fed in 4 phases (approximately 23 to 44, 44 to 71, 71 to 104, and 104 kg to market). Diets included a control corn-soybean meal-based diet formulated to a 19% SID Trp:Lys ratio, 4 diets with 30% DDGS fed in all four phases and formulated to achieve 16%, 19%, 22%, or 25% SID Trp:Lys ratio, respectively, and 2 DDGS withdrawal strategy diets: 19% SID Trp:Lys with 30% DDGS in phase 1 through 3 and then in phase 4, 0% DDGS with either a 19 or 25% Trp:Lys ratio. Overall, BW, ADG, ADFI, and G:F increased (linear, P < 0.05) as SID Trp:Lys ratio increased in diets with 30% DDGS fed in all 4 phases (Table). Pigs fed diets containing a SID Trp:Lys ratio of 19% and 30% DDGS from phases 1 through 3 and 0% DDGS in phase 4 had the greatest numeric ADG and ADFI for the overall study, but was not different than pigs fed the control for ADG, or the 25% Trp:Lys withdrawal treatment and the 30% DDGS diets with 25% Trp:Lys ratio throughout the study for ADG and ADFI. Hot carcass weight and carcass yield increased (quadratic, P < 0.05) as Trp:Lys ratio increased. Carcass fat samples were taken from the loin-butt junction and analyzed for iodine value. Pigs fed the control diet had decreased (P < 0.05) carcass fat iodine value compared with pigs fed DDGS throughout the study, with pigs fed the two DDGS withdrawal strategies having decreased (P < 0.05) iodine values compared with pigs fed 30% DDGS in all 4 phases. In summary, increasing the SID Trp:Lys ratio in diets with 30% DDGS resulted in a linear improvement in ADG, ADFI, G:F, and BW but did not influence iodine values. Removing DDGS from the diet in the last period reduced carcass fat iodine value and increased growth rate during the withdrawal period compared with pigs fed 30% DDGS throughout, indicating value in a DDGS withdrawal strategy.