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Pork hot carcass weights (HCW) have been increasing 0.6 kg per year, and if they continue to increase at this rate, they are projected to reach an average weight of 118 kg by the year 2050. This projection in weight is a concern for pork packers and processors given the challenges in product quality from heavier carcasses of broiler chickens. However, previous work demonstrated that pork chops from heavier carcasses were more tender than those from lighter carcasses. Therefore, the objective was to determine the effects of pork hot carcass weights, ranging from 90 to 145 kg with an average of 119 kg, on slice shear force and sensory traits of Longissimus dorsi chops when cooked to 63 or 71 °C, and to assess if differences in chilling rate can explain differences in sensory traits. Carcasses were categorized retrospectively into fast, medium, or slow chilling-rates based on their chilling rate during the first 17 h postmortem. Loin chops cut from 95 boneless loins were cooked to either 63 or 71 °C and evaluated for slice shear force and trained sensory panel traits (tenderness, juiciness, and flavor) using two different research laboratories. Slopes of regression lines and coefficients of determination between HCW and sensory traits were calculated using the REG procedure in SAS and considered different from 0 at P ≤ 0.05. As hot carcass weight increased, chops became more tender as evidenced by a decrease in SSF (63 °C β = -0.0412, P = 0.01; 71 °C β = -0.1005, P0.001). Furthermore, HCW explained 25% (R2 = 0.2536) of the variation in chilling rate during the first 5 h of chilling and 32% (R2 = 0.3205) of the variation in chilling rate from 5 to 13 h postmortem. Slow- and medium-rate chilling carcasses were approximately 12 kg heavier (P0.05) than fast chilling carcasses. Slice shear force of chops cooked to 63 and 71 °C was reduced in slow and medium chilling compared with fast chilling carcasses. Carcass temperature at 5 h postmortem explained the greatest portion of variation (R2 = 0.071) in slice shear force of chops cooked to 63 °C. These results suggest that carcasses tend to chill slower as weight increases, which resulted in slight improvements in sensory traits of boneless pork chops regardless of final degree of doneness cooking temperature.Pork carcass weights have increased year over year for at least the past 25 yr. The poultry industry has experienced similar increases in carcass weights in the recent past. The increases in broiler carcass weights have resulted in detrimental impacts on quality. Contrary to the poultry industry, increases in pork carcass weights have resulted in a general improvement in pork quality, including tenderness. The underlying cause of these improvements has not been explained. In the present study, chilling rate was associated with carcass weights, particularly during the first 5 h postmortem. In fact, carcass temperature measured in the Longissimus dorsi muscle at 5 h postmortem was the most predictive of instrumental tenderness values when boneless pork chops were cooked according to UDSA guidelines for whole-muscle pork products. The metabolic conversion of muscle to meat is most active during this initial chilling period. Therefore, chilling rate, which is associated with carcass weight, may be influencing the conversion of muscle to meat and provide some explanation as to why heavy carcasses result in more tender pork chops.

Shiga toxin-producing Escherichia coli (STEC) are major foodborne human pathogens that cause mild to hemorrhagic colitis, which could lead to complications of hemolytic uremic syndrome. Seven serogroups, O26, O45, O103, O111, O121, O145, and O157, account for the majority of the STEC illnesses in the United States. Shiga toxins 1 and 2, encoded by stx1 and stx2, respectively, and intimin, encoded by eae gene, are major virulence factors. Cattle are a major reservoir of STEC, but swine also harbor them in the hindgut and shed STEC in the feces. Our objectives were to use a culture method to isolate and identify major and minor serogroups of STEC in finisher pig feces. Shiga toxin genes were subtyped to assess public health implications of STEC. Fecal samples (n = 598) from finisher pigs, collected from 10 pig flows, were enriched in E. coli broth and tested for stx1, stx2, and eae by a multiplex PCR (mPCR) assay. Samples positive for stx1 or stx2 gene were subjected to culture methods, with or without immunomagnetic separation and plating on selective or nonselective media, for isolation and identification of stx-positive isolates. The culture method yielded a total of 178 isolates belonging to 23 serogroups. The three predominant serogroups were O8, O86, and O121. The 178 STEC strains included 26 strains with stx1a and 152 strains with stx2e subtypes. Strains with stx1a, particularly in association with eae (O26 and O103), have the potential to cause severe human infections. All stx2-positive isolates carried the subtype stx2e, a subtype that causes edema disease in swine, but is rarely involved in human infections. Several strains were also positive for genes that encode for enterotoxins, which are involved in neonatal and postweaning diarrhea in swine. In conclusion, our study showed that healthy finisher pigs harbored and shed several serogroups of E. coli carrying virulence genes involved in neonatal diarrhea, postweaning diarrhea, and edema disease, but prevalence of STEC of public health importance was low. HIGHLIGHTS

Shiga toxin-producing Escherichia coli (STEC) are major foodborne pathogens and seven serogroups, O26, O45, O103, O111, O121, O145, and O157, that account for the majority of the STEC-associated il...

This study focuses on the critical role instructional communication plays in effective risk and crisis communication. More specifically, we examined efforts made by the United States’ swine industr...

Background While porcine biological hazards have had the potential to be transmitted through feed and feed mills for decades, the emerging threat of foreign animal disease has elevated the concern that these may enter or be transmitted throughout the domestic swine herd via a feed vehicle. Objective The goal of this review was to describe the current classification for emerging porcine biological pathogen transmission through the feed supply chain so resources can be best directed towards those of highest risk. Methods By assessing the pathogen severity to pigs and the probability of pathogen transmission through feed, an overall risk can be established using a hazard analysis matrix. Results There is negligible risk for feed‐based transmission of a transmissible spongiform encephalopathy, Trichinella spiralis, Toxoplasma gondii, Salmonella Choleraesuis, Salmonella spp. except Choleraesuis and I 4,[5],12:i:‐, porcine deltacoronavirus, Senecavirus A, mammalian orthoreovirus 3, foot and mouth disease virus, classical swine fever virus or Chinese pseudorabies virus. However, the combined severity and probability of Salmonella enterica serotype I 4,[5],12:i:‐, porcine epidemic diarrhoea virus and African swine fever virus warrant a moderate risk characterization for transmission through the US feed supply chain. Conclusions This risk can be maintained below critical status by minimizing the likelihood that a pathogen can enter the feed supply chain, such as by excluding high‐risk ingredients from facilities, extending biosecurity to mills, and considering proactive mitigation strategies. In reality, all these actions may be necessary to prevent the detrimental transmission of porcine biological hazards into the US swine herd through the feed supply chain., While porcine biological hazards have had the potential to be transmitted through feed and feed mills for decades, the emerging threat of foreign animal disease has elevated the concern that these may enter or be transmitted throughout the domestic swine herd via a feed vehicle. By assessing the pathogen severity to pigs and the probability of pathogen transmission through feed, an overall risk can be established using a hazard analysis matrix. This risk can be maintained below critical status by minimizing the likelihood that a pathogen can enter the feed supply chain, such as by excluding high‐risk ingredients from facilities, extending biosecurity to mills and considering proactive mitigation strategies.

Two experiments were conducted to determine the effects of feeding 1,500 phytase units (FYT/kg; Ronozyme HiPhos 2,500; DSM Nutritional Products, Parsippany, NJ) when credited with its corresponding nutrient release values to growing-finishing pigs. The assumed phytase release values were 0.146% standardized total tract digestible (STTD) P, 0.102% STTD Ca, 8.6 kcal/kg of net energy (NE), and 0.0217%, 0.0003%, 0.0086%, 0.0224%, 0.0056%, 0.0122%, and 0.0163% standardized ileal digestible Lys, Met, Met+Cys, Thr, Trp, Ile, and Val, respectively. In Exp. 1, 1,215 pigs (PIC 359 × Camborough, initially 28.0 ± 0.46 kg) were used. Pens were assigned to one of three dietary treatments with 27 pigs per pen and 15 pens per treatment. Experimental diets consisted of a control with no added phytase or diets with 1,500 FYT fed either in the grower period (days 0–57) then switched to the control diet until market or fed throughout the entire study (day 0 to market). Diets containing added phytase were adjusted based on the supplier-provided expected nutrient release values. During the grower period, pigs fed the control diet with no added phytase had increased (P < 0.05) average daily gain (ADG) and gain-to-feed ratio (G:F) compared with pigs fed added phytase. Overall, pigs fed either the control or phytase only in the grower period had increased (P < 0.05) ADG and G:F compared with pigs fed phytase until market. In Exp. 2, 2,268 pigs (PIC 337 × 1050, initially 28.5 ± 1.96 kg) were used. There were six dietary treatments with 27 pigs per pen and 14 pens per treatment. Experimental diets consisted of a control with no added phytase or five diets with 1,500 FYT assuming nutrient release values for Ca and P; Ca, P, and Amino Acid (AA); Ca, P, AA, and half of the suggested NE; Ca, P, AA, and full NE; or no nutrient release. Overall, there was no evidence for difference in ADG or average daily feed intake among treatments; however, pigs fed the diet containing 1,500 FYT assuming that no nutrient release had improved (P < 0.05) G:F compared to pigs fed diets containing 1,500 FYT assuming either Ca and P or Ca, P, AA, and full NE release, with others intermediate. In summary, pigs fed phytase-added diets accounting for full nutrient release values in both experiments had the poorest performance. This suggests that using all of the nutrient release values attributed to this source of phytase was too aggressive and resulted in lower nutrient concentrations than needed to optimize performance.

A total of 710 pigs (Line 400 × 200, DNA, Columbus, net energy (NE)) were used in two experiments (Exp. 1: initially, 6.3 ± 0.05 kg; Exp. 2: initially, 6.8 ± 0.05 kg) to evaluate the effects of two medium-chain fatty acid (MCFA) based products on nursery pig growth performance. Following their arrival at the nursery facility, pigs were randomized to pens (five pigs per pen) and allowed a 4-d acclimation period. Thereafter, pens of pigs were blocked by initial weight and randomized to dietary treatment. In Exp. 1, the dietary treatments were a dose titration of: 0%, 0.5%, 1.0%, or 2.0% MCFA-based additive, as well as a diet including 1.0% MCFA from a 1:1:1 blend of C6:0, C8:0, and C10:0. In Exp.2, dietary treatments consisted of a basal diet containing no MCFA (control), the control diet with a 1.0% inclusion of four different blends of MCFA, lactic acid, and monolaurin or a diet with 1.0% added MCFA (a 1:1:1 blend of C6:0, C8:0, and C10:0). The four blends consisted of 50% C6:0, 20% lactic acid, and increasing levels of monolaurin (0%, 10%, 20%, and 30%) at the expense of C12:0 (30%, 20%, 10%, and 0%). Treatment diets were formulated and manufactured in two dietary phases. Data were analyzed as a randomized complete block design with pen as the experimental unit. In Exp. 1, overall (days 0–34), increasing CaptiSURE increased (linear, P ≤ 0.014) average daily gain (ADG) and average daily feed intake (ADFI). Feed efficiency improved (quadratic, P = 0.002) with increasing CaptiSURE up to 1.0% of the diet with no benefit thereafter. There was no evidence for differences between pigs fed 1.0% CaptiSURE and pigs fed the 1.0% MCFA blend of C6:0, C8:0, and C10:0. In Exp. 2, overall (days 0–35), pigs fed the 1.0% 1:1:1 MCFA blend had increased (P < 0.034) ADFI and ADG resulting in 0.9 kg greater final weight (P = 0.014) compared with the control group. There was no evidence that the mean performance of pigs fed the four blends of MCFA, lactic acid, and monolaurin were different from the pigs fed the control diet. In summary, the addition of a 1.0% 1:1:1 blend of C6:0, C8:0, and C10:0 in nursery pig diets improved ADG, ADFI, and gain to feed ratio (G:F) compared with pigs fed the control diet. In addition, providing nursery pigs with the MCFA product CaptiSURE, up to 2% of the diet, resulted in linear improvements in ADG and ADFI. Altering the C12:0 to monolaurin ratio and adding lactic acid did not improve growth performance compared with pigs fed the control diet.

Compensatory growth induced by lysine (Lys) restriction in grow-finish pigs is a complex physiological process affected by many factors and interactions, principally genotype, stage of growth at restriction, nature of nutritional restriction, and patterns of restriction and recovery. The scarcity of standard comparisons across the literature has hindered the characterization of important determinants of compensatory growth. Therefore, the present publication aims to review the current state of knowledge on compensatory growth induced by Lys restriction in grow-finish pigs, develop a database from peer-reviewed literature to standardize comparisons to characterize the occurrence of compensatory growth, and provide practical considerations for compensatory growth under field conditions. The literature search focused on publications directly or indirectly evaluating compensatory growth by having a period of Lys restriction followed by a recovery period of Lys sufficiency for grow-finish pigs. The database included 14 publications and 57 comparisons expressed as relative differences of restricted pigs compared to nonrestricted pigs. The database analysis described compensatory growth into complete, incomplete, and no compensatory growth categories and characterized the patterns of restriction and recovery in each category. The review of literature and database analysis supports the occurrence of compensatory growth induced by Lys restriction in grow-finish pigs. The degree of Lys restriction and duration of restriction and recovery periods seem to be critical in explaining differences between complete and incomplete compensatory growth, whereas Lys level in the recovery period seems to be critical between incomplete or no compensatory growth. Compensatory growth seems to be more likely if: 1) the degree of Lys restriction is between 10% and 30%; 2) Lys restriction is induced before pigs reach their maximum protein deposition; 3) duration of Lys restriction is short (maximum 40–45% overall duration) and duration of recovery period is long (minimum 55–60% overall duration); and 4) Lys level in recovery is close to or above the estimated requirements. In addition, compensatory growth can occur under commercial conditions and there seems to be an opportunity to exploit compensatory growth in grow-finish pigs to reduce feed cost and improve feed efficiency under certain market conditions.

Two experiments were conducted to investigate increasing unground and finely ground soybean hulls fed in meal or pelleted form on nursery and finishing pig performance. In experiment 1, 1,100 nursery pigs (initially 6.8 ± 0.1 kg and 28 d of age) were used in a 42-d study with 11 replicates per treatment. Treatments were arranged in a 2 × 2 × 2 factorial with main effects of soybean hulls (10% vs. 20%), grind type (unground, 617 µ vs. ground, 398 µ), and diet type (pelleted vs. meal form). No three-way or soybean hull level × grind type interactions were observed. Overall, average daily gain (ADG) was increased (P < 0.05) by pelleting, decreased (P < 0.05) by grinding, but unaffected by soybean hull levels. Grind type × diet form interactions were observed (P < 0.05) for gain:feed ratio (G:F) and a tendency for average daily feed intake (ADFI; P < 0.10). This was because grinding soybean hulls decreased (P < 0.05) ADFI and increased (P < 0.05) G:F when fed in meal form; however, grinding did not affect ADFI and decreased (P < 0.05) G:F when diets were pelleted. Increasing soybean hulls increased (P < 0.05) ADFI and decreased (P < 0.05) G:F when diets were fed in meal form, but these effects were not observed when diets were pelleted (diet form × soybean hull level interaction, P < 0.06). In experiment 2, 1,215 pigs (initially 21.1 ± 0.1 kg) were used in a 118-d study with nine replications per treatment. Treatments were a corn–soybean meal–based control diet and four diets arranged in a 2 × 2 factorial with the main effects of soybean hulls (7.5% vs. 15%) and grind type (unground, 787 µ vs. ground, 370 µ). All diets were fed in meal form. No soybean hull level × grind type interactions were observed for any growth or carcass responses. Increasing dietary soybean hulls from 0% to 15%, regardless of particle size, did not affect ADG or ADFI, but decreased (linear, P < 0.02) G:F. Carcass yield, hot carcass weight, and backfat depth decreased (linear, P < 0.03) whereas percentage lean increased (linear, P < 0.01) with increasing soybean hulls. Pigs fed ground soybean hulls had increased backfat depth (P < 0.01) and decreased (P < 0.01) percentage lean and fat-free lean index. In summary, increasing soybean hulls up to 20% decreased G:F in nursery and finishing pigs, whereas pelleting nursery diets improved ADG and eliminated the negative effect of increasing soybean hulls on G:F. Grinding soybean hulls reduced growth performance in nursery and finishing pigs.

Transmission of biological hazards capable of causing disease in livestock can occur through a wide variety of direct and indirect routes. In swine production, there are a large number of possible routes of exposure of a pathogen into a susceptible population. African swine fever virus (ASFV) has been a significant challenge for Southeast Asia since first detected in China in 2018 and has spread through many countries within the region. In order to understand potential transmission pathways within an ASFV endemic region, a diagnostic investigation was performed to determine the level of contamination on a wide variety of surface types within a live animal production, feed manufacturing, and feed distribution system located in Vietnam. All diagnostic testing was performed locally by the production system's internal diagnostic laboratory using real-time polymerase chain reaction (rt-PCR) analysis. Early in the diagnostic investigation, it became clear that feed trucks were a common site of ASFV surface contamination detection. This information resulted in biosecurity-focused actions for feed trucks arriving back at the feed mill, including decontamination of interior truck cab surfaces and washing of exterior truck surfaces with high-pressure water prior to application of surface disinfectants. Additionally, a low number of rt-PCR positive samples were detected within the feed production system, with the greatest number coming from transient surfaces such as high traffic areas and worker clothing. This illustrates the importance of managing employee traffic through procedures such as zoning and separation between clean-dirty areas to reduce the likelihood of pathogen transmission. In conclusion, this report illustrates the importance of routine data capture regarding efficacy of biosecurity procedures which allows for real-time updates and improvement as biosecurity gaps are identified.

This experiment was conducted to evaluate potential replacements for pharmacological levels of Zn (provided by Zn oxide), such as diet acidification (sodium diformate) and low dietary crude protein (CP: 21 vs 18%) on nursery pig performance and fecal dry matter (DM). A total of 360 weaned pigs (Line 200 × 400, DNA, Columbus, NE; initially 5.90 ± 0.014 kg) were used in a 42-d growth study. Pigs were weaned at approximately 21 d of age and randomly assigned to pens (five pigs per pen). Pens were then allotted to one of eight dietary treatments with nine pens per treatment. Experimental diets were fed in two phases: phase 1 from weaning to day 7 and phase 2 from days 7 to 21, with all pigs fed the same common diet from days 21 to 42. The eight treatment diets were arranged as a 2 × 2 × 2 factorial with main effects of Zn (110 mg/kg from days 0 to 21 or 3,000 mg/kg from days 0 to 7, and 2,000 mg/kg from days 7 to 21), diet acidification, (without or with 1.2% sodium diformate), and dietary CP (21% or 18%, 1.40% and 1.35% in phases 1 and 2 vs. 1.20% standardized ileal digestible Lys, respectively). Fecal samples were collected weekly from the same three pigs per pen to determine DM content. No 2- or 3-way interactions (P > 0.05) were observed throughout the 42-d study for growth performance; however, there was a Zn × acidifier × CP interaction (P < 0.05) for fecal DM on day 7 and for the overall average of the six collection periods. Reducing CP without acidification or pharmacological levels of Zn increased fecal DM, but CP had little effect when ZnO was present in the diet. From days 0 to 21, significant (P < 0.05) main effects were observed where average daily gain (ADG) and gain:feed (G:F) increased for pigs fed pharmacological levels of Zn, sodium diformate, or 21% CP (P < 0.065). In the subsequent period (days 21 to 42) after the experimental diets were fed, there was no evidence of difference in growth performance among treatments. Overall (days 0 to 42), main effect tendencies were observed (P < 0.066) for pigs fed added Zn or sodium diformate from days 0 to 21, whereas pigs fed 21% CP had greater G:F than those fed 18% CP. Pig weight on day 42 was increased by adding Zn (P < 0.05) or acidifier (P < 0.06) but not CP. In summary, none of the feed additives had a major influence on fecal DM, but dietary addition of pharmacological levels of Zn or sodium diformate independently improved nursery pig performance.

Research has demonstrated that swine feed can be a fomite for viral transmission and certain feed additives can effectively reduce viral contamination. However, additional information is needed to evaluate the efficacy of additives when feed is inoculated with more than one virus. The objective of this study was to evaluate the efficacy of two feed additives for mitigation of porcine epidemic diarrhea virus (PEDV) and porcine reproductive and respiratory syndrome virus (PRRSV) when inoculated individually or together. Feed additives included: 1) no treatment, 2) 0.33% commercial formaldehyde-based product (Sal Curb, Kemin Industries, Des Moines, IA), and 3) 0.50% medium chain fatty acids blend (MCFA; 1:1:1 ratio of C6:C8:C10, Sigma Aldrich, St. Louis, MO). Samples were inoculated with PEDV and PRRSV alone or together at an inoculation concentration of 106 TCID50/g for all viruses. Once inoculated, feed was stored at ambient temperature for 24-h before analyzed via qRT-PCR. For samples inoculated with PEDV or PRRSV alone, a qRT-PCR assay was used which was designed to detect PEDV or PRRSV nucleic acid. For co-inoculated samples, an assay was designed to independently detect both PEDV and PRRSV within a single reaction. For PEDV alone, there was marginally significant evidence that feed additives resulted in differences in cycle threshold (Ct) value (P = 0.052), but no evidence was observed for pairwise differences. For PRRSV alone, formaldehyde increased Ct compared to the untreated control and MCFA treatment (P < 0.05). For co-infection of PRRSV and PEDV, MCFA and formaldehyde increased Ct (P < 0.05) in comparison to non-treated feed. In summary, formaldehyde increased Ct values in feed when contaminated with PRRSV while both mitigants increased Ct value in feed when co-inoculated with PRRSV and PEDV.

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.

Our objective was to determine the effects of increasing dietary standardized ileal digestible (SID) lysine (Lys) on the growth performance of grow-finish pigs. A total of 1,120 pigs (PIC 337×Camborough, initially 39.0±0.82 kg) were used in a 77-d study. Pigs used in the study were sired by boars ranked in the top 15% of a selected PIC elite boar stud based on index. Pens of pigs were blocked by body weight and randomly allotted to 1 of 5 treatments, which consisted of 85, 95, 105, 115, and 125% of the PIC2016 SID Lys recommendations within each phase. Diets were corn-soybean meal-based and formulated to be iso-caloric. Treatments were achieved with increasing feed-grade amino acids. There were 9 mixed-gender pens per treatment and 24 or 25 pigs per pen. Data were analyzed using generalized linear and nonlinear mixed models with pen as the experimental unit. Competing models included linear, quadratic polynomial (QP), broken-line linear (BLL), and broken-line quadratic (BLQ). Increasing dietary SID Lys from 85 to 125% marginally improved overall average daily gain (ADG, quadratic, P = 0.056), gain to feed ratio (G:F, quadratic, P = 0.062), and final body weight (linear, P = 0.075). There was no evidence for treatment effects on mortality and removals (P > 0.10). The best-fitting models for ADG were QP and BLL. The QP model estimated the maximum ADG at 110.6% (95% CI: 93 to >125%), with 99% of maximum ADG achieved at 97.4%. The BLL plateau was estimated at 105.0% (95% CI: 74 to 136%). The best-fitting model for G:F was QP, estimating the maximum G:F at 107.8% (95% CI: 92 to >125%). In conclusion, the estimated optimum overall SID Lys for 39- to 119-kg pigs sired by high index boars ranged from 105.0 to 110.6% of PIC2016 SID Lys recommendation within each phase, depending on the response criteria and statistical model.

A web application was developed to provide a dynamic feeding program for PIC maternal dam lines during gilt development, gestation, peri-partum, lactation and wean-to-service interval (WSI). These recommendations for each production phase are based on peer-reviewed large-scale commercial research. The tool was developed using the Shiny package of R and includes CSS themes, html widgets, and JavaScript actions. Inputs, include pigs weaned per sow per year (PWSY), farrowing rate (FR), total born (TB), replacement rate, the existing feeding program of the breeding herd and the diet energy and standardized ileal digestible (SID) lysine (Lys) levels. Outputs include the feeding program, nutrient specifications and estimates of economic opportunity and performance improvement. The feeding program is based on user-defined energy and SID Lys levels for the gestation and lactation diets and the PIC nutrient recommendations for the breeding herd. Correspondingly, recommended specifications of other nutrients in the diets are provided and calculated based on the recommended feeding program. The tool provides economic and productivity opportunity analysis by comparing the PIC recommendations and the current user feeding programs. Improvement in PWSY is driven by the energy intake impact on caliper score during breeding and farrowing and consequently to FR and TB. This web application can be used by nutritionists and production managers to compare their current feeding practices to PIC recommendations for highly prolific sows. This will aid in their decision-making process regarding nutrition and feeding programs considering productivity and profitability outcomes.

Boars are a source of genetic improvement and influence farrowing rate and litter size. Overfeeding boars increases incidence of feet and leg problems and reduces libido, whereas underfeeding boars may decrease semen output and libido. To help boar stud personnel estimate the energy requirements and base feeding levels, an interactive web application named PIC Optimum Boar Feeding Tool has been developed. The application encompasses three components, including an input interface using dynamic models to estimate energy requirement, an output interface displaying recommended feeding program, and functional modules facilitating the ease of use. The input interface requests users to provide the start and final weight of boars in isolation, isolation length, boar stud room temperature, number of collections per week, and dietary energy level. The daily energy requirement (Mcal of ME/day) is calculated using the following energy-demanding factors: 1) maintenance, 0.1823 × (body weight, kg)0.665; 2) weight gain, 0.00489 × (average daily gain, kg/d); 3) each degree below 17°C for individually penned boars on slatted floors, 0.00382 × (body weight, kg)0.75; 4) mating activity, 0.0043 × (body weight, kg)0.75; and 5) sperm production, 0.1. These factors and the user-defined inputs including dietary energy, are used to calculate a daily feeding amount. The users also have the option to calculate the recommended feeding level for boars of specified body weight. Other functional modules include a flank-to-flank measurement tool that estimates boar body weight and customized downloadable nutrient specifications. This web application incorporates a spectrum of biological, nutritional, and management aspects to allow boar stud personnel to easily make boar feeding decisions.

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.

Our objective was to determine the effects of increasing dietary standardized ileal digestible (SID) lysine (Lys) on the growth performance of late nursery pigs. A total of 1,125 pigs (PIC 337×Camborough, initially 12.0±0.66 kg) were used in a 21-d study. The pigs used in the study were sired by boars ranked in the top 15% of a selected PIC elite boar stud based on index. Pens of pigs were blocked by body weight and randomly allotted to 1 of 5 treatments containing 0.95, 1.10, 1.20, 1.35, and 1.50% of SID Lys. Diets were corn-soybean meal-based and contained 2,480 Kcal of NE/kg. Treatments were achieved with increasing feed-grade amino acids. There were 9 mixed gender pens per treatment and 25 pigs per pen. Data were analyzed using generalized linear and nonlinear mixed models with pen as the experimental unit. Competing models included linear, quadratic polynomial (QP), broken-line linear (BLL), and broken-line quadratic (BLQ). Increasing SID Lys concentration improved average daily gain (ADG, linear, P < 0.001) and gain to feed ratio (G:F, quadratic, P = 0.011). The best-fitting models for ADG were QP and BLL. The QP model estimated the maximum ADG at 1.43% (95% CI: 1.12 to >1.50%), with 99% of maximum ADG achieved at 1.27%. The BLL plateau was estimated at 1.31% (95%CI: 1.06 to >1.50%). The best-fitting models for G:F were QP, BLL, and BLQ. The QP model estimated the maximum G:F at 1.48% (95%CI: 1.23 to >1.50%), with 99% of maximum G:F achieved at 1.24%. The BLL plateau was estimated at 1.30% (95% CI: 1.18 to 1.41%), whereas the BLQ plateau was estimated at 1.36% (95%CI: 1.14 to >1.50%). In conclusion, the estimated optimum SID Lys concentration for 12- to 26-kg pigs sired by high index boars ranged from 1.30 to 1.48%, depending on the response criteria and statistical model.

Recent research has demonstrated that swine viruses can be transmitted via feed. Chemical feed additives have been suggested for the mitigation of these viruses in complete feed. Therefore, the objective of this study was to evaluate the efficacy of a commercially available formaldehyde-based feed additive, medium chain fatty acid blend (MCFA), and commercially available fatty acid-based products for mitigation of porcine epidemic diarrhea virus (PEDV) and porcine reproductive and respiratory syndrome virus (PRRSV) in a feed matrix. Treatments consisted of: 1) non-treated positive control, 2) 0.33% commercial formaldehyde-based product (Sal Curb; Kemin Industries, Inc.; Des Moines, IA), 3) 0.5% MCFA blend (1:1:1 ratio of C6:0, C8:0, and C10:0, Sigma Aldrich, St. Louis, MO), 4) 0.25%, 5) 0.5%, or 6) 1% of commercial dry mono and diglyceride-based product (Furst Strike; Furst-McNess Company, Freeport, IL), 7) 0.25%, 8) 0.5%, or 9) 1% of commercial dry mono and diglyceride-based product (Furst Protect; Furst-McNess Company, Freeport, IL), 10) 0.25%, 11) 0.5%, or 12) 1% dry mono and diglyceride-based experimental product (Furst-McNess Company, Freeport, IL) with 3 replications/treatment. Treatments were applied to complete swine feed before inoculation with 106 TCID50/g of feed with PEDV or PRRSV. Post inoculation feed was held at ambient temperature for 24 h before being analyzed via qRT-PCR. The analyzed values represent the cycle threshold. Formaldehyde and MCFA decreased (P < 0.05) the detectable RNA of PEDV and PRRSV compared to all other treatments. Furst Strike, Furst Protect, and the experimental product did not significantly impact detectability of PEDV or PRRSV RNA. In conclusion, MCFA and formaldehyde treatments are effective at reducing detection of RNA from PEDV and PRRSV in feed.

An experiment was conducted to determine the effect of reduced crude protein (CP) in diets containing coarse wheat bran (CWB) without pharmacological levels of Zn (ZnO) on growth performance and fecal dry matter (DM) of nursery pigs. A total of 650 pigs (DNA 241′600; initially 6.6 kg), were used with 5 pigs/pen and 26 replicate pens/treatment. Pens were assigned to 1 of 5 treatments in a RCB design based on BW. Treatments were fed for 13-d, contained 4% CWB, and consisted of: 1) diet with pharmacological ZnO (2,000 mg/kg Zn) and 21% CP formulated to 1.35% standardized ileal digestible (SID) Lys; 2) a diet with 110 ppm added Zn and 21% CP (1.35% SID Lys); 3) a diet with 110 ppm added Zn formulated to 18% CP (1.20% SID Lys); 4) an 18% CP diet with 110 ppm added Zn formulated to 1.35% SID Lys by the addition of increased levels of feed grade amino acids; and 5) diet 4 with addition of non-essential amino acids (NEAA; glycine and glutamic acid). Data were analyzed using the lmer function in R. Overall, pigs fed 21% CP with ZnO had increased (P < 0.05) ADG compared to those fed 18% CP (1.35% SID Lys) with high levels of feed grade amino acids or those fed the reduced SID Lys (1.2%) diet. Gain-to-feed ratio was increased (P < 0.05) for pigs fed 21% CP diets and those fed the 18% CP diet with NEAA compared to pigs fed 1.2% SID Lys and pigs fed high levels of feed grade amino acids. Fecal DM was increased (P < 0.05) for pigs fed reduced SID Lys diet. In conclusion, reducing CP (subsequently SID Lys) in diets without ZnO decreased growth performance but increased fecal DM.

Animal feed can be contaminated with fomites carrying swine viruses and subsequently be a vehicle for viral transmission This contamination may not be evenly distributed, and there is no validated sampling method for detection of viruses in animal feed or ingredients The purpose of this experiment was to evaluate the sensitivity of ingredient sampling methods for detection of porcine epidemic diarrhoea virus (PEDV) No animals were used in this experiment, so approval from an animal ethics committee was not necessary Thirteen kg soybean meal was used in a 2x2 factorial plus a control, with 2 doses of PEDV (Low: 10 sup 3 /sup TCID sub 50 /sub /g versus High: 10 sup 5 /sup TCID sup 50 /sup /g) and two sample types (individual probes versus composite sample) Soybean meal was confirmed PEDV negative, then loaded into individual, 1-kg polyethylene tote bags with PEDV introduced after loading the first 100 g There were six replicates per PEDV dose plus a control Ten individual probes or one composite sample per bag were created and analysed for PEDV via qRT-PCR The interaction, dose and sample type were significant for both PEDV presence and quantity No control samples had detectable PEDV At the low dose, no PEDV RNA was detected in individual probes or composite samples, but was confirmed in 100% (32 4 C sub t /sub ) of the inoculant samples This is likely due to loss of sensitivity during the analysis process, which has been previously reported to cause a loss up to 10 C sub t /sub when detecting PEDV in feed or ingredients At the high dose, only 37% (37 7 C sub t /sub ) of the probes had detectable PEDV RNA Composite samples were more sensitive (p 05), with PEDV RNA detected in 100% of samples (35 7 C sub t /sub ) In summary, sampling bulk ingredients for PEDV should include compositing at least 10 individual samples Future research is needed to identify alternative methods that have a similar sensitivity, but require less time and effort to collect such a sample

Three experiments were conducted to determine the effect of three fermented amino acids (AA) with their respective biomass compared to crystalline AA on the growth performance of swine and poultry. In experiment 1, 315 barrows (DNA 200 × 400, initially 11.3 ± 0.69 kg) were allotted to 1 of 4 dietary treatments with 5 pigs per pen and 15 or 16 pens per treatment. Dietary treatments included a negative control (16% standardized ileal digestible [SID] Tryptophan:lysine [Trp:Lys] ratio), positive control (21% SID Trp:Lys ratio from crystalline Trp), or diets containing Trp with biomass to provide 21 or 23.5% SID Trp:Lys ratios, respectively. Pigs fed the positive control or low Trp with biomass diet had increased (P < 0.05) ADG compared to pigs fed the negative control diet, with pigs fed the high Trp with biomass diet intermediate. Pigs fed the low Trp with biomass diet had increased (P < 0.05) G:F compared to the negative control diet, with others intermediate. In experiment 2, 1,320 1-d-old male broilers (Cobb 500, initially 45.2 g) were allotted to one of four dietary treatments with 33 birds per pen and 10 pens per treatment. Dietary treatments included a negative control (58/58% Threonine:lysine [Thr:Lys] ratio), positive control (65/66% Thr:Lys ratio from crystalline Thr), or diets containing Thr with biomass to provide 65/66 or 69/70% Thr:Lys ratios in starter and grower diets, respectively. Broilers fed the positive control or Thr with biomass diets had increased (P < 0.05) ADG compared to broilers fed the negative control diet. Broilers fed the positive control or the low Thr with biomass diet had increased (P < 0.05) G:F compared to the negative control and high Thr with biomass treatments. In experiment 3, 2,100 one-day-old male broilers (Cobb 500, initially 39.4 g) were allotted to one of four dietary treatments with 35 birds per pen and 15 pens per treatment. Dietary treatments included a negative control (59/63% Valine:lysine [Val:Lys] ratio), positive control (75/76% Val:Lys ratio from crystalline Val), or diets containing Val with biomass to provide 75/76 or 84/83% Val:Lys ratios in starter and grower diets, respectively. Broilers fed the positive control or Val with biomass diets had increased (P < 0.05) ADG, ADFI, and G:F compared to those fed the negative control diet. In conclusion, Trp, Thr, or Val with their respective biomass appear to be equally bioavailable and a suitable alternative to crystalline AA in swine and poultry diets.

Four experiments were conducted to investigate the effects of increasing dietary soybean hulls without or with distillers dried grains with solubles (DDGS) and net energy (NE) formulation on nursery pig performance. In experiment 1, a total of 210 nursery pigs (initially 6.6 ± 0.1 kg) were used in a 34-d study. Pigs were fed one of five diets that contained increasing soybean hulls (0%, 5%, 10%, 15%, and 20%). Diets were not balanced for NE. Increasing soybean hulls decreased (linear, P < 0.01) average daily gain (ADG) and gain:feed ratio(G:F), and tended to decrease average daily feed intake (ADFI; quadratic, P < 0.10). In experiment 2, 210 nursery pigs (initially 13.6 ± 0.1 kg) were used in a 20-d study to determine the effect of equal NE formulation in diets with soybean hulls. Pigs were fed one of five diets containing 0% (control), 10%, or 20% soybean hulls either balanced to contain equal NE to the control diet or not balanced for energy. Diets containing 10% and 20% soybean hulls with balanced NE contained 3.60% and 7.15% added soybean oil, respectively. Increasing soybean hulls decreased (linear, P < 0.01) ADG regardless of formulation method. Pigs fed increasing soybean hulls without added fat had decreased (linear, P < 0.01) G:F. Increasing soybean hulls in diets with balanced NE decreased (linear, P < 0.02) ADFI, but did not affect G:F. In experiment 3, 600 pigs (initially 6.8 ± 0.1 kg) were used in a 42-d study. Pigs were fed 1 of 10 diets containing 0%, 3%, 6%, 9%, or 12% soybean hulls without or with DDGS (15% from d 0 to 14, 30% from d 15 to 42). Feeding DDGS reduced (P < 0.04) ADG and ADFI, and tended to increase (P < 0.06) G:F. Increasing soybean hulls decreased G:F quadratically (P < 0.03) in diets without DDGS, but decreased G:F linearly (P < 0.01) in diets with DDGS (soybean hulls × DDGS interaction, P < 0.05). In experiment 4, 304 barrows (initially 11.7 ± 0.2 kg) were used in a 21-d study. Pigs were fed one of eight diets containing 0%, 5%, 10%, or 15% soybean hulls with or without 20% DDGS. No soybean hull × DDGS interactions were observed. Increasing soybean hulls tended to decrease (linear, P < 0.08) G:F. In conclusion, feeding low levels of soybean hulls did not affect nursery pig performance but more than 5% soybean hulls, with or without DDGS, decreased G:F. Formulating diets containing soybean hulls on an equal NE basis eliminated the negative effects on G:F, but the NE (1,003 kcal/kg) of soybean hulls used in this study was underestimated.

Two experiments were conducted to determine the effects of calcium to phosphorus (Ca:P) ratio in diets adequate in standardized total tract digestible (STTD) P on performance of 26- to 127-kg pigs fed diets with or without phytase. Pens of pigs (n = 1,134 in Exp. 1 and n = 1,215 in Exp. 2, initially 26.3 and 25.3 kg) were blocked by body weight (BW) and allotted to treatments in a randomized complete block design. There were 27 pigs per pen with 7 and 9 replicates per treatment in Exp. 1 and Exp. 2, respectively. Treatments were formulated to contain 0.75:1, 1.00:1, 1.25:1, 1.50:1, 1.75:1, and 2.00:1 analyzed Ca:P ratios in Exp. 1, and 0.75:1, 1.00:1, 1.25:1, 1.50:1, and 2.00:1 analyzed Ca:P ratios in Exp. 2. These correspond to a range of 0.96:1 to 2.67:1 and 0.95:1 to 2.07:1 STTD Ca:STTD P ratios in Exp. 1 and Exp. 2, respectively. Experiment 2 diets contained 1,000 phytase units of Ronozyme HiPhos 2500 (DSM Nutritional Products, Inc., Parsippany, NJ) with release values of 0.132% STTD P, 0.144% total Ca, and 0.096% STTD Ca. Diets contained 122% of NRC (2012) STTD P estimates for the weight range across 4 phases. In Exp. 1, increasing Ca:P ratio increased (quadratic, P < 0.05) average daily gain (ADG) and average daily feed intake (ADFI). Feed efficiency (G:F) worsened (quadratic, P < 0.05) at the highest ratio. Hot carcass weight (HCW) and bone ash increased (quadratic, P < 0.05) while carcass yield decreased (linear, P < 0.10) with increasing Ca:P ratio. The maximum responses in ADG, HCW, and bone ash were estimated at 1.38:1, 1.25:1, and 1.93:1 analyzed Ca:P and at 1.82:1, 1.64:1, and 2.57:1 STTD Ca:STTD P, respectively. In Exp. 2, increasing Ca:P ratio increased (quadratic, P < 0.05) ADG and bone ash, and improved G:F (linear, P < 0.05). There was a quadratic increase (P < 0.05) in HCW and decrease in carcass yield (P < 0.10). The maximum responses in ADG, HCW, and bone ash were estimated at 1.63:1, 1.11:1 to 1.60:1, and 1.25:1 analyzed Ca:P and at 1.75:1, 1.28:1 to 1.71:1, and 1.40:1 STTD Ca:STTD P, respectively. Expressing ADG on a STTD Ca:STTD P basis provided a more consistent estimate of the ideal Ca:P ratio among the 2 studies than analyzed Ca to analyzed P ratio. A STTD Ca:STTD P ratio between 1.75:1 to 1.82:1 can be used for 26- to 127-kg pigs that are fed diets adequate in STTD P with or without added phytase to maximize growth rate without reducing bone ash.

A study was conducted to determine the standardized total tract digestible phosphorus (STTD P) requirement for 24- to 130-kg finishing pigs housed under commercial conditions. A total of 1,130 barrows and gilts (PIC 359 × 1050, Hendersonville, TN; initially 24.2 kg) were used, with 26 to 27 pigs per pen with 7 replicates per treatment. Pens of pigs were allotted to treatments in a randomized complete block design with body weight (BW) as the blocking factor. The dietary treatments were fed in 4 phases and were formulated to contain 80%, 90%, 100%, 115%, 130%, and 150% of the National Research Council (NRC) requirement estimate for finishing pigs within each phase. Weight ranges for each phase were: 27 to 49, 49 to 76, 76 to 90, and 90 to 130 kg. Treatments were achieved by increasing the amount of monocalcium phosphate at the expense of corn in the diet with no added phytase. All diets were formulated to contain a similar 1.14:1 to 1.16:1 total Ca:P ratio across treatments in all phases. Increasing STTD P resulted in a quadratic response (P < 0.05) in average daily gain (ADG), gain-to-feed ratio (G:F), and final BW. The greatest improvement was observed with STTD P at 130% of NRC for ADG and final BW and at 115% STTD P for G:F. Average daily feed intake increased linearly (linear, P < 0.05) with the inclusion of STTD P. Increasing STTD P resulted in an increase (quadratic, P < 0.05) in hot carcass weight (HCW) and carcass ADG with the greatest response observed with STTD P at 130% of NRC. There was a marginally significant response (quadratic, P < 0.10) in carcass G:F, with the greatest improvement with STTD P at 115% of NRC. Carcass yield decreased (linear, P < 0.05) with increasing STTD P, while there was a marginally significant (linear, P < 0.10) decrease in backfat and increase in fat-free lean. At the end of the study, a metacarpal was collected and analyzed for bone ash. Increasing STTD P resulted in an increase (linear, P < 0.05) in bone ash weight and percentage ash. For ADG and G:F, the quadratic model demonstrated the best fit. The maximum response in ADG and G:F was estimated at 122% and 116% of NRC STTD P, respectively. The broken-line linear model best fit the data for percentage bone ash, with a plateau achieved at 131% of the NRC STTD P. In conclusion, the estimated STTD P requirement of 24 to 130 kg ranged from 116% to 131% of the NRC publication (2012) requirement estimate.

Two experiments were conducted to determine the effects of feeding chromium propionate (Cr; Kemin Industries, Inc., Des Moines, IA) and a Yucca schidigera-based extract (YS; Distributors Processing, Inc., Porterville, CA) on growth performance of finishing pigs housed in commercial conditions. In experiment 1, a total of 1,188 pigs (PIC 337 × 1050; initially 27.3 ± 0.48 kg body weight [BW]) with 27 pigs per pen and 11 pens per treatment were split by sex upon arrival at the facility and were randomly allotted to groups of four pens blocked by BW. Diets were corn–soybean meal-dried distillers grains with solubles-based and were fed in five phases. Treatments were arranged as a 2 × 2 factorial with main effects of Cr (0 vs. 200 µg/kg) or YS (0 vs. 62.5 mg/kg YS-based feed grade concentrate). Overall, adding Cr alone increased (P = 0.049) average daily feed intake (ADFI), and inclusion of YS resulted in a marginally significant increase (P = 0.077) in ADFI. Backfat depth was increased (P = 0.043) and lean percentage was decreased (P = 0.011) with added Cr. In experiment 2, a total of 2,430 pigs (PIC 359 × 1050; initially 29.3 ± 0.43 kg BW) were placed in balanced mixed-sex pens with 27 pigs per pen, blocked by average pen BW, and randomly assigned to one of six dietary treatments with 14 pens per treatment. Diets were corn–soybean meal-based and were formulated in five dietary phases. Treatments were arranged in a 2 × 3 factorial with main effects of Cr (0 vs. 200 µg/kg added Cr), and YS extract (0, 62.5, or 125 mg/kg YS-based feed grade concentrate). Overall, a marginally significant (linear, P = 0.072) Cr × YS interaction was observed for average daily gain (ADG) where there was insufficient evidence of a difference with increasing YS in diets not including added Cr (P ≥ 0.109); however, ADG increased (quadratic, P = 0.026) with YS addition in treatments fed 200 µg/kg added Cr. For overall ADFI, a marginally significant (linear, P = 0.071) Cr × YS interaction was observed where YS increased ADFI with 200 µg/kg added Cr (linear, P = 0.031), however, did not when diets contained no added Cr (P = 0.700). A marginally significant reduction in gain:feed ratio was observed when 62.5 mg/kg YS was included (quadratic, P = 0.053), and final BW and hot carcass weight were lowest with 62.5 mg/kg YS (quadratic, P = 0.012). In summary, adding Cr propionate along with YS led to modest changes in performance with the greatest benefit observed with 200 µg/kg Cr and 125 mg/kg YS-based feed grade concentrate.

A total of 1,089 pigs (PIC 280 × 1050; initially 37.3 ± 2.8 kg) were used to determine the effects of increasing Cu provided from either CuSO4 alone or a 50:50 blend of CuSO4 and a Copper–amino acid complex (Cu-AA) on growth performance and carcass characteristics of finishing pigs. Pens of pigs were blocked by body weight; within blocks, pens were randomly allotted to one of six dietary treatments. The six dietary treatments consisted of a control diet which contained 17 mg/kg Cu from CuSO4 from the trace mineral premix, or the control diet with either added CuSO4 to provide 70 and 130 mg/kg total Cu or a 50:50 blend of Cu from CuSO4 and Cu-AA (CuSO4/Cu-AA blend) to provide 70, 100, and 130 mg/kg total Cu. Experimental diets were corn–soybean meal-dried distillers grains with solubles-based and fed in meal form in five phases (approximately 37 to 46, 46 to 63, 63 to 77, 77 to 103, and 103 to 129 kg body weight). From d 0 to 43, neither Cu source nor level influenced growth performance. From d 43 to 105, average daily feed intake (ADFI) decreased (P = 0.037) for pigs fed the CuSO4/Cu-AA blend compared to those fed added Cu from CuSO4 alone. Gain:feed ratio (G:F) tended to be improved (linear, P = 0.056) as Cu concentration increased. Overall, d 0 to 105, neither Cu level nor source influenced average daily gain (ADG). Pigs fed 70 or 130 mg/kg total added Cu from the CuSO4/Cu-AA blend had lower (P = 0.045) ADFI but G:F tended to be improved (P = 0.051) compared with those fed the same amount of total Cu from only CuSO4. Owing to the decreased ADFI and improved G:F of pigs fed the CuSO4/Cu-AA blend, carcass G:F also improved (P = 0.033) compared with those fed added Cu from CuSO4 alone. In conclusion, providing a 50:50 blend of CuSO4 and Cu-AA improved G:F on both a live and carcass weight basis compared to CuSO4 alone with no differences in ADG or carcass ADG observed.

Research has shown that carcass yield in swine is reduced when ingredients with high neutral detergent fiber (NDF) content. Carcass yield reduction from feeding high-fiber ingredients results from an increase in the weight of intestinal contents. NDF has been shown to result in the digestive contents to swell in the large intestine by absorbing water thus increasing the fecal volume in the large intestine. Considering the financial implications of changing carcass yield, the objective of this project was to develop a regression equation to estimate carcass yield from dietary NDF and strategies where high-NDF ingredients are taken out of the diet in the last dietary phases before slaughter (withdrawal period; WP). Data from 8 experiments (43 observations) originated from 6 journal articles and 1 technical memo were used to develop the regression equation. The WP of high NDF ingredients was either none or ranged from 5 to 63 d in the experiments. Treatment diets of each trial were reformulated to obtain dietary nutrient content using the NRC ingredient library (NRC, Nutrient requirements of swine. 11th ed, 2012). Composition of experimental diets was used to calculate dietary net energy, crude protein, crude fiber, NDF, and acid detergent fiber in the last two dietary phases. These dietary compositions along with the number of days of WP were used to develop regression equations. The model was determined using a step-wise selection procedure starting with guided forward selection through individual predictor variables, with a statistical significance at P < 0.05 used to determine inclusion of terms in the final model. The regression analysis showed that WP, NDF level in the dietary phase prior to the final phase (NDF1), NDF level in the last dietary phase before marketing (NDF2), and the interaction between NDF2 and WP were the most important variables in the dataset to predict carcass yield. The resulting regression equation was as follows: carcass yield, % = 0.03492 ± 0.02633 × WP (d) – 0.05092 ± 0.02862 × NDF1 (%) – 0.06897 ± 0.02931 × NDF2 (%) – 0.00289 ± 0.00216 × (NDF2 [%] × WP [d]) + 76.0769 ± 1.33730. In conclusion, high levels of NDF up to slaughter had a negative impact on carcass yield. Increasing the length of the WP improved carcass yield; however, the effect of WP was dependent on the level of NDF2. The equation herein provides a tool to estimate of the impact of dietary NDF on carcass yield.

An experiment was conducted to compare the effects of increasing dietary net energy (NE) in finishing pig diets while either maintaining a standardized ileal digestible lysine:NE ratio (SID Lys:NE) or maintaining SID Lys as a constant percentage of the diet across increasing energy densities. A total of 150 pigs (Line 600 × 241; DNA, Columbus, NE; initially 35.7 kg) were used in a 91-d study. Pigs were blocked by sex and weight and randomly assigned to 1 of 5 treatments with 2 pigs per pen and 15 pens per treatment. Treatments included a low-energy control diet that was corn-soybean meal-based with added soybean hulls, and a 2 × 2 factorial arrangement of treatments with main effects of increasing dietary NE (medium or high by adding choice white grease) and formulation method (with a SID Lys:NE ratio or maintaining the same percentage SID Lys). Linear and quadratic contrasts were made using the control diet and the medium- and high-energy diets within each formulation method. Pigs and feeders were weighed approximately every 30 d to calculate average daily gain (ADG), average daily feed intake (ADFI), and gain-to-feed ratio (G:F). At the end of the experiment, pigs were sent to a commercial processing facility for carcass data collection. From days 0 to 34 and 34 to 61, ADG and SID Lys intake increased as NE increased (linear, P < 0.05) in pigs fed diets with a Lys:NE ratio, but not for those fed the same percentage Lys. As NE increased, NE intake and G:F increased (P < 0.01) in pigs fed diets with either formulation method. From days 61 to 91, increasing NE had no effect (P > 0.10) on ADG. There was no change in G:F in pigs fed diets with the same percentage Lys (P > 0.10), but G:F decreased then increased (quadratic, P < 0.01) in response to increasing NE in pigs fed diets with a SID Lys:NE ratio. Overall, increasing dietary NE increased (linear, P < 0.001) daily NE intake and G:F (linear, P < 0.018) with either formulation method. However, SID Lys intake, ADG, and hot carcass weight only increased (linear, P < 0.01) when a SID Lys:NE ratio was maintained. Increasing NE without maintaining a constant SID Lys:NE ratio increased backfat depth (quadratic, P = 0.01), whereas it did not in pigs fed diets with a SID Lys:NE ratio. In conclusion, increasing dietary energy density increased NE intake and G:F regardless of formulation method. However, a SID Lys:NE ratio must be maintained to achieve increased ADG and minimize fat deposition.

The branched-chain amino acids (BCAA) Leu, Ile, and Val share the first steps of their catabolism due to similarities in their structure. The BCAA are reversibly transaminated in skeletal muscle through the activity of branched-chain aminotransferase and then transported to the liver. They undergo an irreversible decarboxylation catalyzed by the branched-chain α-keto acid dehydrogenase complex. Both enzymes are common to Leu, Ile, and Val and increased enzymatic activity stimulated by an excess of one of them will increase the catabolism of all BCAA, which can result in antagonisms. Leucine and its keto acid are the most potent stimulators of BCAA catabolic enzymes. Moreover, BCAA and large neutral amino acids (LNAA) share common brain transporters. Research has shown that high concentrations of BCAA, especially Leu, can decrease the absorption of LNAA, such as Trp, which is a precursor of serotonin and can have a significant impact in feed intake regulation. Finally, high Leu concentrations have the ability to overstimulate the mTOR signaling pathway, resulting in an inhibitory effect on feed intake. Most of the research conducted to evaluate the impact of BCAA on growth performance of pigs seems to agree that high levels of Leu decrease weight gain, mostly due to a reduction in feed intake. However, some studies, mostly with finishing pigs, observed no evidence for an impact on growth performance even with extremely high levels of Leu. It could be hypothesized that these inconsistencies are driven by the entire dietary amino acid profile as opposed to only considering the level of Leu. Grow-finish diets typically contain high levels of Leu, but the other BCAA are also well above the requirement and could potentially mitigate the negative impact of Leu on BCAA catabolism. Indeed, some studies suggest that when diets contain high levels of Leu, more Ile and Val are needed to optimize growth performance. However, the precise relationship between BCAA and their balance in swine diets is not fully understood. More research is needed to understand and quantify the relationship between LNAA and BCAA.

African swine fever virus (ASFV) is a contagious, rapidly spreading, transboundary animal disease and a major threat to pork production globally. Although plant-based feed has been identified as a potential route for virus introduction onto swine farms, little is known about the risks for ASFV transmission in feed. We aimed to determine the minimum and median infectious doses of the Georgia 2007 strain of ASFV through oral exposure during natural drinking and feeding behaviors. The minimum infectious dose of ASFV in liquid was 10(0) 50% tissue culture infectious dose (TCID(50)), compared with 10(4) TCID(50) in feed. The median infectious dose was 10(1.0) TCID(50) for liquid and 10(6.8) TCID(50) for feed. Our findings demonstrate that ASFV Georgia 2007 can easily be transmitted orally, although higher doses are required for infection in plant-based feed. These data provide important information that can be incorporated into risk models for ASFV transmission.

A total of 2,430 pigs (PIC 337 × 1050; Hendersonville, TN; initially 30.1 kg) were used in a 113-d growth trial to determine the effects of increasing dietary Zn on growth performance and carcass characteristics of finishing pigs raised under commercial conditions. Pens of pigs were assigned to be fed one of five dietary treatments in a randomized complete block design. Treatments consisted of 50, 87.5, 125, 162.5, or 200 mg/kg added Zn from Zn hydroxychloride (IntelliBond Z, Micronutrients, Indianapolis, IN). Two identical barns were used for a total of 18 pens per treatment with 27 pigs per pen. Experimental diets were fed in five phases and contained a vitamin-trace mineral premix without added Zn. Pens of pigs were weighed approximately every 2 wk to calculate average daily gain (ADG), average daily feed intake (ADFI), and gain-to-feed ratio (G:F). At the end of the experimental period, pigs were tattooed with a pen identification number and transported to a packing plant to measure hot carcass weight (HCW), backfat, loin depth, and calculated lean percentage. Data were analyzed block nested within barn as a random effect and pen as the experimental unit. From days 0 to 42, pigs fed diets with increasing added Zn had lower (linear, P = 0.043) ADFI and a tendency (P = 0.092) for lower ADG. From days 42 to 113, increasing added Zn resulted in a quadratic response (P = 0.042) for ADFI and a tendency (linear, P = 0.056) for improved G:F. Overall (days 0 to 113), there were tendencies for quadratic responses for ADFI (P = 0.073) and G:F (P = 0.059), with the greatest G:F observed when 125 mg/kg of Zn was fed. Increasing added Zn resulted in a linear increase (P < 0.001) in daily Zn intake. There were no differences (P > 0.10) in overall ADG, final body weight, HCW, backfat, loin depth, lean percentage, mortality, and removal rate. In conclusion, there were no improvements in ADG when feeding beyond 50 mg/kg added Zn; however, providing 125 mg/kg added Zn resulted in the greatest G:F.

Three experiments were conducted to determine the optimal dietary standardized ileal digestible (SID) lysine and CP concentrations for finishing pigs over 100 kg BW. In Exp. 1, 253 pigs (DNA 600 × 241, initially 102.0 kg) were used in a 23-d trial with 7 to 8 pigs per pen and 8 pens per treatment. Dietary treatments contained 4 SID lysine concentrations (0.45, 0.55, 0.65, or 0.75%). To formulate the experimental diets, a corn-soybean meal diet with 0.45% SID lysine was formulated without L-lysine HCl. Then, a corn-soybean meal diet containing 0.75% SID lysine was formulated including 0.23% L-lysine HCl. The 0.45 and 0.75% SID lysine diets were blended to provide the 0.55 and 0.65% SID lysine diets. Increasing SID lysine increased (quadratic, P < 0.05) ADG and ADFI with pigs fed 0.55% SID lysine having the greatest final BW. Marginal improvements in gain:feed (G:F; quadratic, P = 0.058) and carcass yield (linear, P = 0.051) and reduction in backfat (quadratic, P = 0.074) were also observed with increasing SID lysine. The quadratic polynomial models predicted maximum ADG and G:F at 0.62 and 0.63% SID lysine, respectively. The broken-line linear model predicted no further improvement in G:F over 0.55% SID lysine. In Exp. 2, 224 pigs (PIC 327 × 1050, initially 109.4 kg) were used in a 20-d trial with 7 pigs per pen and 7 to 8 pens per treatment. Dietary treatments included 4 concentrations of CP (10, 11, 12, or 13%) that were formed by reducing the amount of L-lysine HCl in a corn-soybean meal diet. Increasing CP increased (linear, P < 0.05) ADG and ADFI with the greatest responses observed in pigs fed the diet with 12% CP. Increasing dietary CP also improved (linear, P < 0.05) G:F, final BW, and hot carcass weight (HCW). In Exp. 3, 238 pigs (DNA 600 × 241, initially 111.8 kg) were used in a 26-d trial with 7 to 8 pigs and 6 pens per treatment. Dietary treatments included 5 concentrations of CP (9, 10, 11, 12, or 13%). Increasing CP improved (quadratic, P < 0.05) ADG and G:F with the greatest response observed in pigs fed 13% CP. Increasing CP marginally increased (quadratic, P < 0.074) HCW, with the greatest response observed in pigs fed 12% CP. In conclusion, the SID lysine requirement for pigs from 100 to 122 kg was 0.55 to 0.63% depending on the response criteria with performance maximized with diets containing 12 to 13% CP.

Dietary phosphorus concentration greatly affects pig’s growth performance, environmental impact and diet cost. A total of 1080 pigs (initially 5.9 ± 1.08 kg) from three commercial research rooms were used to determine the effects of increasing standardized total tract digestible (STTD) P concentrations in diets without and with phytase on growth performance and percentage bone ash. Pens (10 pigs/pen, 9 pens/treatment) were balanced for equal weights and randomly allotted to 12 treatments. Treatments were arranged in two dose titrations (without or with 2000 units of phytase) with six levels of STTD P each. The STTD P levels were expressed as a percentage of NRC (2012) requirement estimates (% of NRC; 0.45 and 0.40% for phases 1 and 2, respectively) and were: 80%, 90%, 100%, 110%, 125% and 140% of NRC in diets without phytase and 100%, 110%, 125%, 140%, 155% and 170% of NRC in diets with phytase. Diets were provided in three phases, with experimental diets fed during phases 1 (days 0 to 11) and 2 (days 11 to 25), followed by a common diet from days 25 to 46. On day 25, radius samples from one median-weight gilt per pen were collected for analysis of bone ash. During the treatment period, increasing STTD P from 80% to 140% of NRC in diets without phytase improved average daily gain (ADG; quadratic, P < 0.01), average daily feed intake (ADFI; quadratic, P < 0.05) and gain–feed ratio (G : F; linear, P < 0.01). Estimated STTD P requirement in diets without phytase was 117% and 91% of NRC for maximum ADG according to quadratic polynomial (QP) and broken-line linear (BLL) models, respectively, and was 102%, 119% and >140% of NRC for maximum G : F using BLL, broken-line quadratic and linear models, respectively. When diets contained phytase, increasing STTD P from 100% to 170% of NRC improved ADG (quadratic, P < 0.05) and G : F (linear, P < 0.01). Estimated STTD P requirement in diets containing phytase was 138% for maximum ADG (QP), and 147% (QP) and 116% (BLL) of NRC for maximum G : F. Increasing STTD P increased (linear, P < 0.01) the percentage bone ash regardless of phytase addition. When comparing diets containing the same STTD P levels, phytase increased (P < 0.01) ADG, ADFI and G : F. In summary, estimated STTD P requirements varied depending on the response criteria and statistical models and ranged from 91% to >140% of NRC (0.41% to >0.63% of phase 1 diet and 0.36% to >0.56% of phase 2 diet) in diets without phytase, and from 116% to >170% of NRC (0.52% to >0.77% of phase 1 diet and 0.46% to >0.68% of phase 2 diet) for diets containing phytase. Phytase exerted an extra-phosphoric effect on promoting pig’s growth and improved the P dose-responses for ADG and G : F.

In wean-to-finish pig production, leftover finisher feed from the previous group is commonly blended with nursery diets as weanling pigs enter the facility. Two experiments were conducted to evaluate feeding the last finisher diet to nursery pigs. The timing (phase) and dose were evaluated. Each experiment used 1,260 pigs from two commercial research rooms with 21 pigs per pen and 30 pens per room (15 pens per treatment). Pigs were fed commercial nursery diets in a five-phase feeding program, and phase changes were based on a feed budget. In experiment 1, pens of pigs (initially 5.83 kg) were blocked by body weight, gender, and room and allotted to one of four treatments. Treatments included standard nursery diets throughout (control) or standard diets with 2.5 kg/pig of the last finisher feed blended at the beginning of phase 2, 3, or 4. Growth responses during the intermediate periods were promptly decreased (P < 0.05) once the finisher feed was introduced regardless of phase in which it was blended. However, during the overall nursery period, blending the finisher diet into phase 2 decreased (P < 0.05) average daily gain (ADG) and average daily feed intake (ADFI), but did not affect gain:feed ratio (G:F), compared with control pigs or those that had blended diet in phase 4 with blending of phase 3 diet intermediate. In experiment 2, weaned pigs were fed common phase 1 and 2 diets before the start of the experiment. At the beginning of phase 3, pens of pigs (initially 10.6 kg) were blocked by body weight and room and allotted to one of four treatments. Treatments consisted of a dose-titration of blending increasing amounts of finisher feed (0, 1.25, 2.50, and 3.75 kg/pig) into the phase 3 nursery diet. Overall, blending increasing amounts of the last finisher feed with phase 3 nursery diet decreased ADG (linear, P = 0.050) and tended to decrease (linear, P < 0.07) ADFI and final body weight. However, there was no evidence for difference in overall G:F. In conclusion, blending finisher feed into the early nursery diets decreased overall ADG and ADFI; however, pigs greater than 11 kg had improved ability to compensate for the negative effects of blending the last finisher feed on overall growth performance. Nevertheless, increasing the amounts of finisher feed fed to 11-kg pigs from 0 to 3.75 kg/pig resulted in a linear decrease in overall ADG and ADFI. Economic analysis indicated no change in income-over-feed-cost due to the timing and dose of blending finisher feed into nursery diets.

Three studies were conducted to determine the effects of source and concentration of Na and Cl on pig growth performance from 7 to 12 kg. In all three experiments, pigs were fed a common diet (0.33% Na and 0.77% Cl) for 7 or 8 d after weaning then randomly assigned to dietary treatments. In Exp. 1, 360 mixed-sex pigs were used in a 14-d study with 15 replications per treatment and six pigs per pen. Treatments included a 10% dried whey diet with 0.60% added salt (0.37% Na and 0.75% Cl); or three diets with 7.2% crystalline lactose with either: 0.35% added salt (0.18% Na and 0.47% Cl); 0.78% added salt (0.35% Na and 0.72% Cl); or 1.15% NaHCO3 and 0.40% KCl (0.35% Na and 0.45% Cl). Pigs fed the 0.78% added salt-lactose diet had greater (P < 0.05) ADG than pigs fed the 0.35% added salt-lactose diet, with others intermediate. In Exp. 2, 360 barrows were used in a 14-d study with 12 replications per treatment and five pigs per pen. Treatments included two added salt diets (providing 0.13% Na and 0.35% Cl or 0.35% Na and 0.68% Cl), three diets with Na and Cl provided by KCl and NaHCO3 (0.13%, 0.35%, or 0.57% Na and 0.50% Cl), or a diet with NaHCO3 and CaCl2 (0.35% Na and 0.50% Cl). Regardless of Na source, ADG and ADFI increased (quadratic, P < 0.05) as dietary Na increased from 0.13% to 0.35%, with no further benefits observed thereafter. There was no evidence for differences among pigs fed NaCl or NaHCO3 nor evidence for differences among pigs fed the different Na and Cl sources at similar concentrations. In Exp. 3, 300 pigs were used in a 21-d trial with 10 replications per treatment and five pigs per pen. Treatments included a control diet with added salt to provide 0.33% Na and 0.55% Cl or five diets with 0.33 % Na and added KCl to provide 0.09, 0.21, 0.32, 0.45, or 0.55% Cl. ADG and G:F increased (quadratic, P < 0.035) as Cl increased from 0.09% to 0.32%. Pigs fed the control diet (added salt) and the 0.55% Cl diet had similar ADG. For ADG and ADFI, the broken line linear model indicated a breakpoint of 0.23% Cl. For G:F, the quadratic polynomial model suggested the maximum at 0.38% Cl. In conclusion, 7 to 12 kg pigs fed diets that contained at least 0.35% Na and 0.38% Cl had greater ADG and G:F compared to pigs fed diets with lower concentrations and minimal effects were observed among the sources of Na or Cl used in these studies.

The systematic approach to raising pigs in a multi-site production system, in terms of where the pigs are housed and how long they are fed, is generally called pig flow. This complex process is most often approached in a segmented fashion, not looking at all barns at the same time in relation to each other. Linear programming, the basis of most nutritional formulation packages and logistics services, provides a mathematical means for characterizing pig flow that allows a producer to look at the entire flow of pigs in a system at the same time. We describe a teaching model that provides the foundation to characterize pig flow in a commercial production system. The teaching model is built in Microsoft Excel® and incorporates key components of production such as growth rate, mortality, stocking density, seasonality, packer grid pricing, and marketing. The results from this teaching model are sound and provide the foundation for a larger model that is needed for full implementation within a production system, proving this model behaves as expected. The generalizability of the model and its assumptions allows for the inclusion of more barns, a more precise measure of time, and the ability to change the assumptions utilized in this teaching scenario, which are needed for direct application in a production system.

In a 72-d trial, 256 pigs (Line 600 × 241, DNA Columbus, NE) were used to determine the effect of dietary Cr (Cr propionate; Kemin Industries, Des Moines, IA) and physical space restriction on performance and carcass characteristics of finishing pigs. Pens were blocked by initial weight and randomly assigned to treatments with eight pigs per pen and eight pens per treatment. Treatments were arranged in a 2 × 2 factorial with main effects of Cr (control and Cr propionate, 200 µg/kg added Cr) and space allowances (0.91 m2/animal: normal and 0.63 m2/animal: restricted). Pigs were fed in three dietary phases and pigs were weighed approximately every 14 d throughout the study. Feed efficiency was calculated as both a standard gain to feed ratio and as an adjusted G:F ratio at a common final bodyweight. There were no evidence of space allocation × Cr interactions for any measured responses (P > 0.05). Space restriction decreased (P < 0.001) daily weight gain, final body weight, hot carcass weight, and daily feed intake, but increased carcass yield (P = 0.009) and decreased backfat depth (P = 0.003). Feed efficiency was greater for pigs provided a normal space allowance when adjusted for a common final bodyweight (P = 0.021), although no evidence of a difference was observed for unadjusted G:F (P = 0.687). Adding Cr to the diet reduced G:F on both an adjusted and unadjusted basis (P ≤ 0.021). There was marginally significant evidence that pigs provided Cr had lower average daily gain (P = 0.079) and final bodyweight (P = 0.056) compared to pigs not provided added Cr. There was marginally significant evidence that Cr resulted in greater backfat depth (P = 0.069), although no evidence of a difference in other carcass parameters were observed (P > 0.10). These results demonstrated that there were no interactions between Cr propionate and space allocation, illustrating that under the conditions of this study Cr propionate did not provide an advantage in growth performance or carcass characteristics in either adequate or restricted space allocation.