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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.

Two experiments were conducted to evaluate the effects of Fe injection timing after birth on suckling and subsequent nursery and growing-finishing pig performance. The injectable Fe source used in both experiments was GleptoForte (Ceva Animal Health, LLC., Lenexa, KS). GleptoForte contains gleptoferron which is a Fe macromolecule complex. In Exp. 1, a total of 324 newborn pigs (DNA 241 × 600, initially 1.6 ± 0.04 kg body weight [BW]) within 27 litters were used. Two days after birth, all piglets were weighed, and six barrows and six gilts per litter were allotted to 1 of 6 treatments consisting of no Fe injection or 200 mg of injectable Fe provided in a single injection on d 2, 4, 6, 8, or 10 of age. Pigs were weaned (~21 d of age) and allotted to nursery pens with all pigs in each pen having received the same Fe treatment. In Exp. 2, a total of 1,892 newborn pigs (PIC 359 × C40; initially 1.5 ± 0.02 kg BW) within 172 litters were used. One day after birth, piglets were weighed, and 11 pigs within each litter were allotted to 1 of 6 treatments consisting of no Fe injection or 200 mg of injectable Fe provided on d 1, 3, 5, or 7 of age, or 200 mg on d 1 plus 200 mg on d 12 of age. Pigs were weaned (19 d of age) and placed in a commercial wean-to-finish facility in a total of 15 pens with equal representation of treatments in each pen. In both experiments, not providing an Fe injection after birth decreased (P < 0.05) preweaning average daily gain (ADG), weaning weight, and hemoglobin and hematocrit values compared with all other treatments. In Exp. 1, increasing the age that piglets received an Fe injection until 4 or 6 d after birth provided marginal evidence for an improvement (quadratic; P = 0.070) in preweaning ADG. For the nursery period, increasing the age that piglets received an Fe injection improved (quadratic; P = 0.013) d 80 BW, but there was no evidence of a difference (P > 0.10) in d 173 BW at the end of the grow-finish period. In Exp. 2, increasing the age that piglets received a 200 mg Fe injection showed no evidence of difference (P > 0.10) for subsequent nursery and growing-finishing ADG. In both experiments, hemoglobin and hematocrit values were decreased (linear; P < 0.05) at weaning with increasing age when pigs received an Fe injection. These experiments suggest that providing a 200 mg Fe injection within 7 d after farrowing is sufficient for optimizing preweaning and subsequent growth performance.

Weaned pigs (n=1,722; 5.9 kg BW) were used in a 53-d study evaluating the effects of Fe injection timing on subsequent nursery pig performance. Treatments consisted of a negative control for piglets receiving no Fe injection or 200-mg of injectable Fe (GleptoForte, Ceva Animal Health, Lenexa, KS) provided on d 1, 3, 5, or 7 of age, or 200-mg on d 1 plus an additional 200-mg injection on d 12. At weaning, pigs were placed in a commercial wean-to-finish facility in a total of 15 pens with equal representation of treatments in each pen. Pigs were weighed on d 73 after birth to determine subsequent nursery growth performance. Growth data were analyzed (GLIMMIX procedure of SAS) as a completely randomized design with individual pig as the experimental unit and pen as a random effect. Increasing the age that piglets received a 200-mg Fe injection showed no evidence of difference (P >0.10) for subsequent nursery ADG (Table 1). Not providing an Fe injection after birth decreased (P=0.0001) subsequent nursery ADG and decreased (P=0.0001) d 73 BW compared to all other treatments. Providing a 200-mg injection of Fe on d 1 plus a 200-mg injection on d 12 decreased (P=0.010) subsequent nursery ADG and decreased (P=0.024) d 73 BW compared to pigs receiving a 200-mg injection on d 1 only. There was no evidence of difference (P >0.10) for nursery mortality amongst the treatments. These results suggest that providing a 200-mg Fe injection within 7 d after farrowing is sufficient for optimizing subsequent nursery growth performance. The additional 200-mg Fe injection at d 12 decreased subsequent nursery growth performance and ending BW.

A total of 140 weanling pigs (241 × 600, DNA, Columbus, NE; initially 5.5 ± 0.79 kg body weight) were used in a 32-d study evaluating the effects of increasing dietary Fe from either iron sulfate (FeSO4) or iron carbonate (FeCO3) on nursery pig growth performance and blood Fe status. The pigs used for this trial did not receive an Fe injection after birth in order to increase the sensitivity to added dietary Fe after weaning. Pigs were weaned at approximately 21 d and allotted to pens based on the initial weight in a completely randomized block design with five pigs in each pen and four pens per treatment. Experimental treatments were arranged as a 2 × 3 + 1 factorial with main effects of dietary Fe source (FeSO4 vs. FeCO3) and level (10, 30, or 50 mg/kg of added Fe) plus a negative control with no additional dietary Fe. The basal diet contained 40 mg/kg total dietary Fe based on ingredient contributions and was formulated with an Fe-free trace mineral premix. Experimental diets were formulated below the pigs recommended Fe requirement based on NRC (2012) estimates. Experimental diets were fed in pellet form in a single phase for the duration of the trial. From day 0 to 32, there was no evidence for source × level interactions for growth performance, hemoglobin (Hb), or hematocrit (Hct) values. There was no evidence for a difference (P > 0.10) in dietary Fe source. Providing increasing Fe levels in the diet from either FeSO4 or FeCO3 improved (P < 0.05) average daily gain, average daily feed intake, gain-to-feed ratio, and increased (P < 0.05) Hb and Hct values. A day effect (P = 0.001) was observed for both Hb and Hct with values increasing throughout the study. Increasing dietary Fe levels in the diet from either FeSO4 or FeCO3 increased (linear; P < 0.05) Hb and Hct values on days 14, 21, and 32. In summary, these data suggest that the micronized form of FeCO3 is a source of Fe that can be added to nursery diets to yield similar responses to those observed from FeSO4 supplementation. Similar to previous research, increasing dietary Fe improved the growth performance and increased Hb and Hct values when pigs have low Fe status at weaning.

Background Two experiments were conducted to determine the effects of increasing amounts of soybean meal (SBM) in swine diets and estimate the energy value of SBM. Methods A total of 2233 pigs (PIC 337 × 1050, Hendersonville, TN) and 3796 pigs (PIC 359 × C40), initially 11.0 kg and 17.6 kg body weight (BW), were used in Exp. 1 and 2, respectively. In Exp. 1, pigs were placed in 92 pens each containing 20 to 27 pigs. In Exp. 2, pigs were placed in 84 pens each containing 37 to 43 pigs. Treatments were assigned in a randomized complete block design with BW as the blocking factor. Dietary treatments consisted of 21%, 27%, 33%, or 39% SBM in Exp. 1 and 17.5%, 22%, 26.5%, 31%, 35.5%, or 40% SBM in Exp. 2, obtained by changing the inclusion rate of feed-grade amino acids and corn grain. For Exp. 1, representative samples of corn grain, SBM, and distillers dried grains with solubles were analyzed for total AA content prior to diet formulation. For Exp. 2, diets were formulated using NRC (2012) nutrient loadings. Treatment diets were fed for 21 and 22 d (Exp. 1 and 2) and there were 23 replicates in Exp. 1 and 14 replicates in Exp. 2. Pigs were weighed and feed disappearance measured weekly to calculate average daily gain (ADG), average daily feed intake (ADFI), gain-to-feed ratio (G:F), and caloric efficiency (CE). Data were analyzed with block as a random effect and treatment as a fixed effect, and contrasts were constructed to test the linear and quadratic effects of increasing SBM. Results In Exp. 1, there was a tendency (linear, P = 0.092) for a decrease in ADFI as SBM increased. There was a tendency (P = 0.090) for a quadratic response for ADG, with a decrease in ADG observed with 39% SBM inclusion. Pigs fed diets with increasing SBM had a tendency (quadratic, P = 0.069) for an increase in G:F up to 33% SBM and an improvement (linear, P = 0.001; quadratic, P = 0.063) in CE with increasing SBM. Using CE to estimate the energy of SBM relative to corn, a value of 105.4% of corn energy or 2816 kcal/kg NE was determined using all data points. When removing the CE value of the 39% SBM treatment due to the quadratic tendency, SBM was estimated to have 121.1% of corn energy or 3236 kcal/kg NE. In Exp. 2, there was a decrease (linear, P = 0.001) in ADFI. Pigs fed increasing SBM had a tendency (linear, P = 0.065) for reduced ADG but an improvement (linear, P = 0.001) in G:F and CE as SBM increased. The energy value of SBM was estimated as 124.7% of corn energy or 3332 kcal/kg NE. Conclusions The results suggest that feeding increasing levels of SBM improves G:F and CE. The energy value of SBM was estimated to be between 105% and 125% of corn, which is much greater than the NRC (2012) would indicate.

A total of 336 newborn pigs (DNA 241 × 600, initially 1.75 ± 0.05 kg bodyweight [BW]) from 28 litters were used in a 63-d study evaluating the effects of increasing injectable Fe dose on suckling and subsequent nursery pig performance and blood Fe status. GleptoForte (Ceva Animal Health, LLC, Lenexa, KS) contains gleptoferron which is an Fe macromolecule complex that is commercially used as an injectable Fe source for suckling piglets. On the day of processing (day 3 after birth), all piglets were weighed and 6 barrows and 6 gilts per litter were allotted within sex to 1 of 6 treatments in a completely randomized design. Treatments consisted of a negative control receiving no Fe injection and increasing injectable Fe to achieve either 50, 100, 150, 200 mg, or 200 mg plus a 100 mg injection on day 11 after birth. Pigs were weaned (~21 d of age) and allotted to nursery pens based on BW and corresponding treatment in a completely randomized design. During lactation, increasing injectable Fe up to 100 mg improved (quadratic; P < 0.05) average daily gain (ADG) and day 21 BW with no further improvement thereafter. There was no evidence of differences (P > 0.10) observed between the 200 mg and 200 mg + 100 mg treatments for growth. For the nursery period, increasing Fe dosage increased (linear; P < 0.05) ADG, average daily feed intake, and day 42 BW. There was no evidence of differences (P > 0.10) between the 200 mg and 200 mg + 100 mg treatments for nursery growth. For blood criteria, significant treatment × day interactions (P = 0.001) were observed for hemoglobin (Hb) and hematocrit (Hct). The interactions occurred because pigs that had

Three studies evaluated the effects of added dietary salt on growth performance of pigs weighing 7 to 10, 11 to 30, and 27 to 65 kg. In experiment 1, 325 pigs were used with 5 pigs per pen and 13 pens per treatment. Pigs were fed a diet (0.39% Na and 0.78% Cl) for 7 d after weaning, then randomly assigned to diets with either 0, 0.20, 0.40, 0.60, or 0.80% added salt for 14 d. All diets were corn-soybean meal-based with 10% dried whey. Calculated Na concentrations were 0.11, 0.19, 0.27, 0.35, and 0.43% and calculated Cl concentrations were 0.23, 0.35, 0.47, 0.59, and 0.70%, respectively. Increasing salt increased (linear, P < 0.05) average daily gain (ADG) and gain to feed ratio (G:F). For ADG, the linear, quadratic polynomial (QP), and broken-line linear (BLL) models were competing with the breakpoint for the BLL at 0.59% salt. For G:F, the BLL reported a breakpoint at 0.33% while the QP indicated maximum G:F at 0.67% added salt. In experiment 2, 300 pigs were used in a 34-d trial with 5 pigs per pen and 12 pens per treatment. Pigs were weaned at 21 d of age and fed a phase 1 diet (0.50% Na and 0.67% Cl) for 11 d and then a phase 2 diet (0.35% Na and 0.59% Cl) for 14 d. Then pens of pigs were randomly assigned to corn-soybean meal-based diets containing 0.20, 0.35, 0.50, 0.65, or 0.80% added salt. Calculated dietary Na concentration were 0.10, 0.16, 0.22, 0.28, and 0.34% and calculated Cl concentrations were 0.23, 0.32, 0.41, 0.50, and 0.59%, respectively. Overall, ADG and G:F increased (quadratic, P < 0.07) with increasing added salt. For ADG, the QP and BLL had similar fit with the breakpoint for BLL at 0.51% added salt. For G:F, the BLL model predicted a break point at 0.35% added salt. In experiment 3, 1,188 pigs were used in a 44-d study with 27 pigs per pen and 11 pens per treatment. Pens of pigs were randomly assigned to corn-soybean meal-based diets containing 0.10, 0.33, 0.55, or 0.75% added salt. Calculated dietary Na concentrations were 0.10, 0.19, 0.28, and 0.36% and calculated Cl concentrations were 0.23, 0.36, 0.49, and 0.61%, respectively. Overall, there was no evidence to indicate that added salt above 0.10% of the diet affected growth. In conclusion, the BLL models suggested to maximize ADG for 7 to 10 and 11 to 30 kg pigs was 0.59% (0.34% Na and 0.58% Cl) and 0.51% added salt (0.22% Na and 0.42% Cl), respectively. There was no evidence that growth of 27 to 65 kg pigs was improved beyond 0.10% added salt (0.11% Na and 0.26% Cl).

Newborn pigs (n=1,892; 1.5 kg BW) were used in a 20-d study evaluating the effects of Fe injection timing after birth on preweaned pig performance and blood criteria. A total of 172 litters were used. One d after farrowing, piglets were weighed, and 11 pigs within each litter were allotted to 1 of 6 treatments in a CRD. Treatments consisted of pigs receiving no Fe injection or 200-mg of injectable Fe (GleptoForte, Ceva Animal Health, Lenexa, KS) provided on d 1, 3, 5, or 7 of age, or 200-mg on d 1 plus 200-mg on d 12. 1 pig/litter received no Fe injection and 2 pigs/litter were placed on all other treatments. Piglets were weighed on d 1 and 20 after birth to determine growth performance and bled on d 20 to determine Fe status. Increasing the age that piglets received the Fe injection tended to decrease (linear; P=0.080) ADG. Not providing an Fe injection decreased (P=0.0001) overall ADG and d 20 BW compared to all other treatments. Hemoglobin and Hct decreased (linear; P< 0.05) with increasing age when pigs received an Fe injection. There was no evidence of differences (P >0.10) between the pigs receiving a 200-mg injection on d 1 and d 12 compared to those receiving the Fe on d 1 only. Pigs not provided an Fe injection had decreased (P=0.0001) Hb and Hct values compared to pigs receiving an Fe injection. Pigs receiving the 200-mg injection on d 1 and 12 had increased (P=0.0001) Hb and Hct values compared to pigs receiving 200-mg on d 1 only. Results suggest that providing a 200-mg Fe injection within 7 d after farrowing is sufficient for optimizing preweaning growth performance. The additional 200-mg Fe injection at d 12 did not influence growth performance but does increase Hb and Hct at weaning.

Recent research has reported that increasing standardized ileal digestible (SID) Trp:Lys ratio above 20% in finishing pigs fed Ractopamine HCL (RAC) resulted in improved growth and carcass performance, however this response has been inconsistent. Therefore, the objective of this study was to evaluate the effects of feeding high SID Trp:Lys ratios with RAC on growth and carcass performance. A total of 1,791 finishing pigs (PIC 1050×337; initially 110 kg BW) were used in a 27-d study. Pens of 25 or 26 pigs were allotted by initial BW and randomly assigned to 1 of 5 dietary treatments in a RCBD with 14 replications per treatment. The dietary treatments consisted of 5 SID Trp:Lys ratios (20, 22, 24, 26, and 28%). Corn-soybean meal-based diets were formulated to 0.90% SID Lys and contained 10 ppm ractopamine. At d 27, pigs were transported to a packing plant for processing and carcass data collection. Growth data were analyzed (GLIMMIX procedure of SAS) as a RCBD with pen as the experimental unit and initial BW as a covariate. Carcass data were analyzed with pen as the experimental unit and block × treatment as the random effect. Hot carcass weight served as a covariate for analysis of backfat, loin depth, and lean percentage. For overall growth performance, increasing SID Trp:Lys increased (linear, P< 0.0001) SID Trp g/kg of gain and SID Trp intake (Table 1); however, there were no evidence of treatment differences (P >0.10) for ADG or G:F. For carcass characteristics, increasing SID Trp:Lys decreased (linear; P=0.002) carcass yield and tended to decrease (P=0.078) lean percentage. There was no evidence of treatment differences (P >0.10) for HCW, loin depth, carcass ADG, or carcass feed efficiency. In summary, increasing SID Trp:Lys ratios above 20% in pigs fed RAC did not improve growth or carcass performance.

Weaned pigs (n = 308; 5.7 kg BW) were used in a 42-d study evaluating the effects of increasing injectable Fe dose at processing (d 3 after farrowing) on subsequent nursery pig performance and hematological criteria. Pigs were weaned on d 21 and allotted to pens based on previous Fe treatment with BW balanced across pens within a treatment with 5 or 6 pigs/pen and 10 pens/treatment. Treatments applied at processing were a negative control receiving no Fe injection or increasing injectable Fe (Gleptoforte, Ceva Animal Health, Lenexa, KS) to provide 50, 100, 150, 200-mg, or 200-mg plus 100-mg on d 11 post-farrowing. All pigs were fed the same diets after weaning containing 110 mg/kg of Fe from FeSO4 provided from the trace mineral premix. Growth data were analyzed as a CRD with pen as the experimental unit. Hematological criteria were analyzed as a repeated measure with pig as the experimental unit. Overall, increasing injectable Fe improved (linear; P < 0.05) ADG and ADFI (Table 1). Increasing injectable Fe up to 150 mg improved (quadratic; P = 0.011) G:F with a worsening G:F thereafter. There was no evidence of difference in growth performance (P > 0.10) between the 200-mg and the 200 + 100 mg injectable Fe treatments. Significant treatment×day interactions (P < 0.001) were observed for Hgb and Hct because pigs receiving an Fe injection less than 150-mg had increasing values through nursery while all other pigs had values remaining constant until d 63 after birth with no evidence of difference (P > 0.10) amongst all treatments at d 63 after birth. These results suggest that providing a 200-mg Fe injection at processing provides the greatest growth performance in the nursery and Fe in the diet is sufficient to meet the pigs’ Fe requirement to restore blood Fe status at the end of the nursery.

A total of 350 pigs (DNA 400×200, initial BW=6.3 kg) were used in a 34-d growth trial to evaluate the effects of a medium chain fatty acid (MCFA)-based feed additive in nursery pig diets. Following arrival to the nursery facility, pigs were randomized to pens (5 pigs per pen) and allowed a 4-d acclimation period. Thereafter, pens of pigs were blocked by BW and randomized to 1 of 5 dietary treatments (14 pens per treatment). Treatments were a dose response of 0, 0.5, 1.0, or 2.0% MCFA-based additive (CaptiSURE, Kemin Industries, Inc.; Des Moines, IA) as well as a treatment including 1.0% MCFA from a 1:1:1 blend of C6, C8, and C10 (Sigma Aldrich, St. Louis, MO). Treatment diets were formulated and manufactured in two dietary phases (d 0 to 13 and 13 to 34). Data were analyzed as a randomized complete block design with pen serving as the experimental unit. Overall (d 0 to 34), increasing CaptiSURE increased (linear, P ≤ 0.014) ADG and ADFI. Feed efficiency improved (quadratic, P = 0.002) with increasing CaptiSURE up to 1% of the diet with no benefit thereafter. As a result of the linear improvement in ADG, pigs fed 2.0% CaptiSURE were 1.8 kg heavier (P = 0.05) than pigs fed diets without MCFA at d 34. There was no evidence for differences between pigs fed 1.0% CaptiSURE and pigs fed the 1.0% MCFA blend of C6, C8, and C10 in phase 1, phase 2 or in overall performance. In summary, the addition of up to 2% of this MCFA-based additive in nursery pig diets resulted in linear improvements in ADG and ADFI. The MCFA-based feed additive also resulted in a similar improvement in growth performance as the C6, C8, and C10 MCFA blend when both were added at 1% of the diet.

Nursery pigs (n = 3,796; 17.6 kg BW) were used in a 22-d study evaluating the effects of increasing soybean meal on nursery pig performance. At 8 weeks of age, pens were allotted to treatment based on location in a randomized complete block design with 39 to 40 pigs per pen. Ten pens were placed on the positive control treatment and 12 pens placed on all other treatments. Experimental diets were fed in one phase (d 0 to 22) in meal form. Treatments included a positive control diet with 40% soybean meal and 1.8% choice white grease. Six diets were formulated with increasing soybean meal (17.5 to 40%) without added fat. Pigs were weighed on d 0, 13, and 22 to determine ADG, ADFI, G:F and NE efficiency. Growth data were analyzed as a randomized complete block design with pen as the experimental unit. Growth data were evaluated using linear and quadratic effects of soybean meal level and a pairwise comparison of the 40% soybean meal treatments with and without added fat. An outbreak of E. coli-associated disease was noted in the first 2 weeks of the experiment. Overall, increasing soybean meal tended to decrease (linear; P = 0.070) ADG, decreased (linear; P = 0.0001) ADFI, improved (linear; P = 0.0001) G:F and caloric efficiency, and reduced (linear; P = 0.050) removal rate (Table 1). Pigs fed the positive control had decreased (P = 0.019) ADFI and improved (P = 0.001) G:F compared to pigs fed the 40% soybean meal diet without added fat. These results suggest the net energy value for soybean meal was underestimated in diet formulation. Increasing soybean meal level in the diet reduced removal rate, suggesting soybean meal may provide added health benefits beside amino acids and energy.

Weaned pigs (n = 311; 5.9 kg BW) were used in a 59-d study evaluating the effects of Fe injection timing after birth on nursery pig performance and hematological criteria. Pigs were weaned at 21 d and allotted to pens based on preweaning Fe treatment with BW balanced across pens within a treatment with 5 or 6 pigs/pen and 10 pens/treatment. The preweaning treatments were a negative control receiving no Fe injection or 200-mg of injectable Fe (Gleptoforte, Ceva Animal Health, Lenexa, KS) provided in a single injection on d 2, 4, 6, 8, or 10 after birth. All pigs were fed common diets after weaning that contained 110 mg/kg of added Fe as FeSO4 provided from the trace mineral premix. Growth data were analyzed as a completely randomized design with pen as the experimental unit. Hematological criteria were measured as a repeated measure with pig as the experimental unit. Overall, increasing the age of pigs receiving a 200-mg Fe injection from 2 to 4 or 6 d after birth increased (quadratic; P = 0.013) d 80 ending BW with a decrease in BW when Fe was provided on d 8 or 10 (Table 1). Not providing an Fe injection after birth worsened (P < 0.05) ADG, ADFI, and d 80 ending BW. Significant treatment×day interactions (P < 0.001) were observed for Hgb and Hct values. These interactions occurred because pigs not receiving an Fe injection after birth had values that increased from d 21 to 35 while pigs receiving an Fe injection had values that decreased from d 21 to 35. While it is common practice to provide an Fe injection within the first 48 hours of birth, these results suggest delaying injection until d 4 or 6 may increase nursery final weight.

A total of 2,673 mixed sex pigs (DNA 600 × PIC 1050; initially 21.4 kg BW) were used in a 117-d study to evaluate the effects of increasing SID Lysine:Calorie NE ratio on the growth performance and carcass characteristics of DNA sired pigs. Pens of pigs (30 pigs/pen) were blocked by BW and location and allotted to 1 of 4 dietary treatments with 18 pens per treatment. Treatments were 90%, 95%, 100%, or 105% of the 2016 PIC recommended SID Lysine:Calorie NE ratio for finishing gilts. Data were analyzed as a randomized complete-block design with pen as the experimental unit. Overall (d 0-117), increasing Lysine:Calorie NE tended to improve ADG (Linear; P = 0.077) and G:F (Linear; P = 0.053). Although there was an increase in ADG with increasing SID Lysine:Calorie NE, there was no evidence for a difference (P > 0.100) in final BW. The lack of BW response is most likely due to the lower (Quadratic; P < 0.008) removal rate as SID Lysine:Calorie NE increased. Carcass ADG (Linear; P < 0.064) tended to improve as SID Lysine: Calorie NE increased. An improvement in carcass G:F (Quadratic; P < 0.004) was observed as SID Lysine:Calorie NE increased to 100% PIC (2016) recommendations, with little improvement observed thereafter. No significant differences were observed in carcass yield, loin depth, back fat, or % lean. These results suggests that DNA sired pigs fed increasing SID Lysine:Calorie NE ratios tended to have improved growth performance with no impact on carcass quality.

A total of 300 nursery pigs (initially 5.9 ± 0.05 kg BW) were used in a 42-d growth trial to evaluate the effects of feeding a therapeutic level of chlortetracycline (CTC) with or without direct fed microbials (DFM) on growth performance and antimicrobial resistance (AMR) of fecal Escherichia coli. CTC is a broad-spectrum in-feed antibiotic commonly used in the swine industry. Weaned pigs (~21 d of age) were allotted to pens based on initial BW and fed a common starter diet for 4 d. Pens were then blocked by BW and allotted to dietary treatments in a completely randomized block design. Dietary treatments were arranged in a 2 × 3 factorial consisting of combinations of CTC (none vs. 400 mg/kg from days 0 to 42) and DFM (0 vs. 0.05% DFM 1 vs. 0.05% DFM 2). Fecal samples were collected from three randomly selected pigs from each pen on days 0, 21, and 42 for E. coli isolation and AMR determination. Overall, pigs fed diets containing CTC had improved (P < 0.001) ADG, ADFI, and BW compared to those not fed CTC with no evidence for any effect of either DFM 1 or DFM 2. Regardless of CTC, inclusion of DFM 2 in diets improved (P < 0.05) ADFI from days 0 to 14 and on day 14 BW compared to diets that did not include DFM 2. The addition of CTC with or without DFMs to nursery pig diets increased (P < 0.05) the probability of AMR to tetracycline and ceftiofur of fecal E. coli isolates, but this resistance generally decreased (P < 0.05) over time. A decrease (P < 0.05) in AMR to ampicillin and tetracycline (TET) throughout the trial was observed, while resistance to ceftriaxone decreased (P < 0.020) from days 0 to 21 and increased from days 21 to 42 amongst dietary treatments regardless of CTC or DFM inclusion in the diet. A CTC × DFM × day interaction (P < 0.015) was observed for streptomycin, whereby from days 21 to 42 AMR increased in diets containing either CTC or DFM 1 alone, but the combination decreased resistance. There was no evidence for any effect of DFMs on AMR of fecal E. coli isolates to any other antibiotics evaluated. In conclusion, therapeutic levels of added CTC with or without DFM inclusion improved nursery pig performance, but increased AMR of fecal E. coli isolates to TET and ceftiofur. A moderate improvement in intake and day 14 BW was observed when DFM 2 was included in the diet with or without CTC, but, except for streptomycin, there was no evidence that added dietary DFMs affected resistance of fecal E. coli to antibiotics.

Three studies evaluated the effects of added dietary salt on growth performance of pigs weighing 7 to 10, 11 to 30, and 27 to 65 kg. In experiment 1, 325 pigs were used with 5 pigs per pen and 13 pens per treatment. Pigs were fed a diet (0.39% Na and 0.78% Cl) for 7 d after weaning, then randomly assigned to diets with either 0, 0.20, 0.40, 0.60, or 0.80% added salt for 14 d. All diets were corn-soybean meal-based with 10% dried whey. Calculated Na concentrations were 0.11, 0.19, 0.27, 0.35, and 0.43% and calculated Cl concentrations were 0.23, 0.35, 0.47, 0.59, and 0.70%, respectively. Increasing salt increased (linear, P < 0.05) average daily gain (ADG) and gain to feed ratio (G:F). For ADG, the linear, quadratic polynomial (QP), and broken-line linear (BLL) models were competing with the breakpoint for the BLL at 0.59% salt. For G:F, the BLL reported a breakpoint at 0.33% while the QP indicated maximum G:F at 0.67% added salt. In experiment 2, 300 pigs were used in a 34-d trial with 5 pigs per pen and 12 pens per treatment. Pigs were weaned at 21 d of age and fed a phase 1 diet (0.50% Na and 0.67% Cl) for 11 d and then a phase 2 diet (0.35% Na and 0.59% Cl) for 14 d. Then pens of pigs were randomly assigned to corn-soybean meal-based diets containing 0.20, 0.35, 0.50, 0.65, or 0.80% added salt. Calculated dietary Na concentration were 0.10, 0.16, 0.22, 0.28, and 0.34% and calculated Cl concentrations were 0.23, 0.32, 0.41, 0.50, and 0.59%, respectively. Overall, ADG and G:F increased (quadratic, P < 0.07) with increasing added salt. For ADG, the QP and BLL had similar fit with the breakpoint for BLL at 0.51% added salt. For G:F, the BLL model predicted a break point at 0.35% added salt. In experiment 3, 1,188 pigs were used in a 44-d study with 27 pigs per pen and 11 pens per treatment. Pens of pigs were randomly assigned to corn-soybean meal-based diets containing 0.10, 0.33, 0.55, or 0.75% added salt. Calculated dietary Na concentrations were 0.10, 0.19, 0.28, and 0.36% and calculated Cl concentrations were 0.23, 0.36, 0.49, and 0.61%, respectively. Overall, there was no evidence to indicate that added salt above 0.10% of the diet affected growth. In conclusion, the BLL models suggested to maximize ADG for 7 to 10 and 11 to 30 kg pigs was 0.59% (0.34% Na and 0.58% Cl) and 0.51% added salt (0.22% Na and 0.42% Cl), respectively. There was no evidence that growth of 27 to 65 kg pigs was improved beyond 0.10% added salt (0.11% Na and 0.26% Cl).

Formaldehyde-based feed additives are approved in the US for Salmonella control and reducing bacterial contamination in animal feed. However, we hypothesize formaldehyde inclusion in swine diets may influence gut microbial composition due to its antimicrobial properties which might negatively influence microbial populations and pig growth performance. Also, formaldehyde inclusion in diets is known to reduce the dietary availability of amino acids. Therefore, our study was conducted to characterize if the effects of feed formaldehyde-treatment are due to influences on microbial population or diet amino acid (AA) sources. Dietary treatments were arranged in a (2 × 2) + 1 factorial with formaldehyde treatment (none vs. 1000 ppm formaldehyde) and crystalline AA inclusion (low vs. high) with deficient AA content plus a positive control diet to contain adequate AA content without dietary formaldehyde. Treating diets with formaldehyde reduced growth rate (P = 0.001) while the AA inclusion had no evidence of impact. Formaldehyde reduced feed bacterial content and altered fecal microbial communities (P

A total of 300 nursery pigs (initially 5.9 ± 0.05 kg BW) were used in a 42-d growth trial to evaluate the effects of feeding a therapeutic level of chlortetracycline (CTC) with or without direct fed microbials (DFM) on growth performance and antimicrobial resistance (AMR) of fecal Escherichia coli. CTC is a broad-spectrum in-feed antibiotic commonly used in the swine industry. Weaned pigs (~21 d of age) were allotted to pens based on initial BW and fed a common starter diet for 4 d. Pens were then blocked by BW and allotted to dietary treatments in a completely randomized block design. Dietary treatments were arranged in a 2 × 3 factorial consisting of combinations of CTC (none vs. 400 mg/kg from days 0 to 42) and DFM (0 vs. 0.05% DFM 1 vs. 0.05% DFM 2). Fecal samples were collected from three randomly selected pigs from each pen on days 0, 21, and 42 for E. coli isolation and AMR determination. Overall, pigs fed diets containing CTC had improved (P < 0.001) ADG, ADFI, and BW compared to those not fed CTC with no evidence for any effect of either DFM 1 or DFM 2. Regardless of CTC, inclusion of DFM 2 in diets improved (P < 0.05) ADFI from days 0 to 14 and on day 14 BW compared to diets that did not include DFM 2. The addition of CTC with or without DFMs to nursery pig diets increased (P < 0.05) the probability of AMR to tetracycline and ceftiofur of fecal E. coli isolates, but this resistance generally decreased (P < 0.05) over time. A decrease (P < 0.05) in AMR to ampicillin and tetracycline (TET) throughout the trial was observed, while resistance to ceftriaxone decreased (P < 0.020) from days 0 to 21 and increased from days 21 to 42 amongst dietary treatments regardless of CTC or DFM inclusion in the diet. A CTC × DFM × day interaction (P < 0.015) was observed for streptomycin, whereby from days 21 to 42 AMR increased in diets containing either CTC or DFM 1 alone, but the combination decreased resistance. There was no evidence for any effect of DFMs on AMR of fecal E. coli isolates to any other antibiotics evaluated. In conclusion, therapeutic levels of added CTC with or without DFM inclusion improved nursery pig performance, but increased AMR of fecal E. coli isolates to TET and ceftiofur. A moderate improvement in intake and day 14 BW was observed when DFM 2 was included in the diet with or without CTC, but, except for streptomycin, there was no evidence that added dietary DFMs affected resistance of fecal E. coli to antibiotics.

Newborn pigs (n = 324; 1.6 kg BW) were used in an 19-d study evaluating the effects of Fe injection timing after birth on preweaned pig performance and blood criteria. A total of 27 litters were used, with the number of pigs per sow equalized on each day of farrowing. Two d after farrowing, all piglets were weighed, and six barrows and six gilts within each litter were allotted to 1 of 6 treatments in a CRD. Treatments consisted of a negative control receiving no Fe injection or 200 mg of injectable Fe (Gleptoforte, Ceva Animal Health, Lenexa, KS) provided on d 2, 4, 6, 8, or 10 after farrowing. Piglets were weighed and bled on d 2, 12, and 21 after birth to determine growth performance and blood Fe status. Overall, increasing the age that piglets received a 200 mg Fe injection until 4 or 6 d after birth tended to increase (quadratic; P = 0.065) ADG (Table 1). Not providing an Fe injection tended to decrease (P = 0.070) overall ADG and decreased (P = 0.0003) d 21 BW compared to all other treatments. Significant treatment×day interactions (P < 0.001) were observed for hemoglobin (Hgb) and hematocrit (Hct). The interactions occurred because pigs injected with 200 mg of Fe on d 2, 4, 6, or 8 after birth had increasing values until d 21 after birth, while pigs receiving a 200 mg Fe injection on d 10 after birth had decreasing values to d 12 then increasing values to d 21. Pigs not provided an Fe injection after birth had decreasing values to d 21. These results suggest that providing a 200 mg Fe injection on d 4 or 6 after farrowing provided the greatest preweaning growth performance and blood Fe status until weaning.

Newborn pigs (n = 336; 1.7 kg BW) were used in a 21-d study evaluating the effects of increasing injectable Fe on preweaning pig performance and blood Fe status. A total of 28 litters were used and at processing (d 3 after farrowing) all piglets were weighed and six barrows and six gilts/litter were allotted to 1 of 6 treatments in a CRD. Treatments consisted of a negative control receiving no Fe injection and increasing injectable Fe (Gleptoforte, Ceva Animal Health, Lenexa, KS) to achieve 50, 100, 150, 200-mg, or 200-mg plus a 100-mg injection on d 11 post-farrowing. Piglets were weighed and bled on d 3, 11, and 21 of age to determine growth performance and blood Fe status. Preweaned pig growth data and hematological criteria were evaluated using individual pig as the experimental unit with hematological criteria analyzed as a repeated measure. Increasing injectable Fe up to 100-mg improved (quadratic; P < 0.05) ADG and d 21 BW with no further improvement thereafter (Table 1).There were no evidence of differences (P > 0.10) between the 200-mg and 200 + 100-mg treatments for growth. Significant treatment×day interactions (P < 0.001) were observed for hemoglobin (Hgb) and hematocrit (Hct). The interactions were the result of decreased values for pigs receiving no Fe injection or an Fe injection of 100-mg or less, while pigs receiving an Fe injection greater than 100-mg had increased values at d 21. Pigs receiving the 200 + 100-mg treatment had increased (P < 0.05) Hgb and Hct values compared to pigs receiving a single 200-mg Fe injection on d 21. Results suggest that a 100-mg Fe injection is sufficient for growth performance during the preweaning phase, but an Fe injection greater than 100-mg is needed to maximize blood criteria. An extra 100-mg Fe injection at d 11 did not influence growth performance but does increase Hgb and Hct at weaning.

Two separate studies were conducted at one commercial feed mill and six commercial wean-to-finish pig sites in northwest Iowa to determine the effects of feed truck unloading auger RPM on pellet quality and unloading time (Exp. 1) and the effects of feed line location on pellet quality and nutrient concentration of intact pellets and their fines (Exp. 2). For Exp. 1, feed samples were taken from each compartment of an 8-compartment, 24-ton Walinga (Walinga Inc., Guelph, Ontario) feed truck. Feed was unloaded using 3 unloading speeds as determined by the truck RPM of 900, 1,150, and 1,400. Each compartment was timed during unloading, and percentage fines and PDI were determined from each sample taken. The same truck was used 6 times, allowing for 16 replications per unloading speed and 6 replications per compartment. The compartment located closest to the truck cab was denoted as compartment 1, and the compartment located closest to the rear of the truck was denoted as compartment 8. An unloading speed × trailer compartment interaction (P = 0.031) was observed. The difference in unloading time for each compartment became progressively less, the closer the compartment was to the back of the truck. The percentage of fines formed was not significantly different among unloading speeds. The percentage of fines formed during unloading tended to increase (quadratic; P = 0.081) from the first to the eighth compartment, with the maximum percentage of fines formed occurring in the fifth compartment. In Exp. 2, pelleted feed was sampled as feed was unloaded into a commercial feed bin at 6 wean-to-finish barn sites. Each barn was equipped with 2 separate feed lines that transported feed from the bin into the barn. Feed samples were taken inside the barn at the feeder closest to the bin (20 ft), halfway from the bin (115 ft), and the farthest from the bin (250 ft) for each feed line. Samples were analyzed for percentage fines and PDI. During analysis, fines and complete pellets were separated, and a nutrient profile was determined for each. No interactions were observed between feed line location and nutrient profile of the fines and pellets. There was no effect of feed line location on pellet PDI, percentage fines, percentage fines formed, or pellet and fines nutrient profile. Fines had decreased (P < 0.05) CP and P but increased (P < 0.05) ADF, crude fiber, Ca, ether extract, and starch were observed when compared to the composition of pellets. In conclusion, feed flow from the compartments closer to the cab resulted in fewer fines formed from loading to unloading. Decreasing unloading speed significantly increased the amount of time taken to unload a feed truck. No differences were observed in the amount of fines formed for any of the unloading speeds. There appear to be no differences in pellet quality among feed line locations within a commercial wean to finish barn; however, there are significant differences in nutrient profile between fines and pellets.

Citation: De Jong, J. A., DeRouchey, J. M., Tokach, M. D., Goodband, R. D., Woodworth, J. C., Jones, C. K., . . . Haberl, B. (2016). (Young Scholars) Effects of feed truck unloading and swine barn feed line location on pellet quality and nutrient segregation. Journal of Animal Science, 94, 78-78. doi:10.2527/msasas2016-166