Exploring zinc deficiency using serum Zn levels: consequences and potential solutions in suckling pigs.

Three trials were undertaken to provide an answer to different questions: 1) Are suckling pigs able to maintain physiological serum Zn levels throughout lactation and do these levels vary between high and low body weight (BW) pigs?, 2) Are serum Zn levels in pigs soon after weaning a predisposing factor for diarrhea?, and 3) Is it possible to increase serum Zn levels at weaning by supplementing Zn during lactation. In trial 1, blood samples were taken from pigs during lactation. Eight pigs (one piglet per litter) had blood drawn on days 0 (farrowing), 7, 14, 21, and 28 (weaning), and 60 pigs (selected from the whole farrowing batch with 35 sows), categorized as either heavy (8.63 kg) or light (5.50 kg) had blood drawn on day 28. Serum Zn levels at birth were 1.2 mg/L and decreased (P < 0.01) to 0.67 mg/L on day 28. Heavier pigs showed greater (P < 0.01) serum Zn levels (0.98 mg/L) than light BW pigs (0.79 mg/L). In trial 2, blood samples were obtained from 240 pigs at weaning (26.2 ±â€…2.5 d) with an average initial BW of 6.94 ±â€…1.87 kg and were distributed into 24 pens (10 pigs/pen) by BW. Diarrhea incidence was recorded daily from days 0 to 35 post-weaning. From the 240 pigs, a group of 110 pigs with uniform BW (6.5 ±â€…1.9 kg) was selected and separated into two groups based on serum Zn levels at weaning with 55 pigs with low serum Zn (LZn: <0.71 mg/L) and 55 pigs with high serum Zn (HZn: >0.9 mg/L). Pigs with LZn were 2.49 times as likely to have diarrhea as pigs with HZn (P < 0.02). In trial 3, a total of 96 suckling pigs were allotted four treatments that consisted of the daily administration of 0, 6, 18, or 30 mg of Zn as Zn citrate in capsule form during the last 7 d of lactation. Pigs were individually weighed, and blood samples were obtained on days 14, 21 (weaning), and 7 after weaning. Serum Zn levels linearly increased by day as Zn citrate supplementation increased (interaction, P < 0.001). However, only light pigs supplemented with 18 and 30 mg/L of Zn experienced an increase in serum Zn levels during lactation. In conclusion, a decrease in serum Zn levels occurs during lactation and is more severe in low BW pigs. Low Zn status (< 0.7 mg/L) at weaning may be a predisposing factor for diarrhea. However, Zn supplementation during lactation can mitigate this decrease in light pigs.

At weaning, young pigs may experience a decrease in serum Zn levels which can predispose them to diarrhea, particularly when fed diets with nutritional Zn levels. For several decades, this gap has been covered by using therapeutic levels of Zn. However, due to the negative collateral effects of these supra doses, from June 2022 in the EU the maximum level of Zn allowed in piglet diets is 150 mg/kg. In this scenario, it is imperative to investigate the Zn status evolution in pigs even before weaning, to anticipate the appearance of Zn deficiencies. This study had three main objectives: to investigate the Zn serum levels of light and heavy body weight pigs during lactation, to study these Zn levels as a predisposing factor to developing diarrhea during weaning and to study the effects of extra Zn supplementation during lactation to prevent Zn deficiency while weaning. Overall, the results indicate a decrease in pig serum Zn levels during lactation which is more severe in low body weight pigs. Low Zn status at weaning may be a predisposing factor for diarrhea. Nevertheless, external pig supplementation with Zn during lactation can mitigate this issue.

Impacts of dietary copper on the swine gut microbiome and antibiotic resistome.

Restrictions on antibiotic growth promoters have prompted livestock producers to use alternative growth promoters, and dietary copper (Cu) supplementation is currently being widely used in pig production. However, elevated doses of dietary Cu constitute a risk for co-selection of antibiotic resistance and the risk may depend on the type of Cu-based feed additives being used. We here report the first controlled experiment investigating the impact of two contrasting Cu-based feed additives on the overall swine gut microbiome and antibiotic resistome. DNA was extracted from fecal samples (n = 96) collected at four time points during 116 days from 120 pigs allotted to three dietary treatments: control, divalent copper sulfate (CuSO4; 250 µg Cu g-1 feed), and monovalent copper oxide (Cu2O; 250 µg Cu g-1 feed). Bacterial community composition, antibiotic resistance genes (ARGs), and mobile genetic elements (MGEs) were assessed, and bioavailable Cu ([Cu]bio) was determined using whole-cell bacterial bioreporters. Cu supplementation to feed increased total Cu concentrations ([Cu]total) and [Cu]bio in feces 8-10 fold and at least 670-1000 fold, respectively, but with no significant differences between the two Cu sources. The swine gut microbiome harbored highly abundant and diverse ARGs and MGEs irrespective of the treatments throughout the experiment. Microbiomes differed significantly between pig growth stages and tended to converge over time, but only minor changes in the bacterial community composition and resistome could be linked to Cu supplementation. A significant correlation between bacterial community composition (i.e., bacterial taxa present) and ARG prevalence patterns were observed by Procrustes analysis. Overall, results of the experiment did not provide evidence for Cu-induced co-selection of ARGs or MGEs even at a Cu concentration level exceeding the maximal permitted level for pig diets in the EU (25 to 150 µg Cu g-1 feed depending on pig age).

How copper can impact pig growth: comparing the effect of copper sulfate and monovalent copper oxide on oxidative status, inflammation, gene abundance, and microbial modulation as potential mechanisms of action.

The beneficial effect of elevated concentrations of copper (Cu) on growth performance of pigs has been already demonstrated; however, their mechanism of action is not fully discovered. The objective of the present experiment was to investigate the effects of including Cu from copper sulfate (CuSO4) or monovalent copper oxide (Cu2O) in the diet of growing pigs on oxidative stress, inflammation, gene abundance, and microbial modulation. We used 120 pigs with initial body weight (BW) of 11.5 ± 0.98 kg in 2 blocks of 60 pigs, 3 dietary treatments, 5 pigs per pen, and 4 replicate pens per treatment within each block for a total of 8 pens per treatment. Dietary treatments included the negative control (NC) diet containing 20 mg Cu/kg and 2 diets in which 250 mg Cu/kg from CuSO4 or Cu2O was added to the NC. On day 28, serum samples were collected from one pig per pen and this pig was then euthanized to obtain liver samples for the analysis of oxidative stress markers (Cu/Zn superoxide dismutase, glutathione peroxidase, and malondialdehyde, MDA). Serum samples were analyzed for cytokines. Jejunum tissue and colon content were collected and used for transcriptomic analyses and microbial characterization, respectively. Results indicated that there were greater (P < 0.05) MDA levels in the liver of pigs fed the diet with 250 mg/kg CuSO4 than in pigs fed the other diets. The serum concentration of tumor necrosis factor-alpha was greater (P < 0.05) in pigs fed diets containing CuSO4 compared with pigs fed the NC diet or the diet with 250 mg Cu/kg from Cu2O. Pigs fed diets containing CuSO4 or Cu2O had a greater (P < 0.05) abundance of genes related to the intestinal barrier function and nutrient transport, but a lower (P < 0.05) abundance of pro-inflammatory genes compared with pigs fed the NC diet. Supplementing diets with CuSO4 or Cu2O also increased (P < 0.05) the abundance of Lachnospiraceae and Peptostreptococcaceae families and reduced (P < 0.05) the abundance of the Rikenellaceae family, Campylobacter, and Streptococcus genera in the colon of pigs. In conclusion, adding 250 mg/kg of Cu from CuSO4 or Cu2O regulates genes abundance in charge of the immune system and growth, and promotes changes in the intestinal microbiota; however, Cu2O induces less systemic oxidation and inflammation compared with CuSO4.

Copper is a nonrenewable mineral resource that is essential for all biological organisms. After banning the antibiotics, copper has received considerable attention due to its antimicrobial properties that improve performance in animals when fed over the minimum requirement. The present study evaluated two sources of Cu (copper sulfate and monovalent copper oxide) compared with a nonsupplemented diet and the likely mechanism of action which leads to improved pig performance. Pigs fed high concentrations of copper sulfate showed increased liver oxidation and inflammatory indicators in the blood. Elevated concentrations of Cu improved intestinal epithelial barrier function, modulation of inflammatory responses, increased beneficial microbes, and reduced pathogens in the gut. Therefore, supplementation of high levels of Cu appears to be effective in promoting pig growth, but therapeutic doses of Cu sulfate increase the inflammatory response.

Effects of supplemental d-methionine in comparison to l-methionine on nitrogen retention, gut morphology, antioxidant status, and mRNA abundance of amino acid transporters in weanling pigs.

An N-balance experiment was conducted to test the hypothesis that d-Methionine (d-Met) has the same bioavailability and efficacy as l-Methionine (l-Met) when fed to weanling pigs. A Met-deficient basal diet containing 0.24% standardized ileal digestible (SID) Met was formulated. Six additional diets were formulated by adding 0.036%, 0.072%, or 0.108% d-Met or l-Met to the basal diet, and these diets, therefore, contained 77%, 87%, or 97% of the requirement for SID Met. Fifty-six barrows (10.53 ± 1.17 kg) were housed in metabolism crates and allotted to the seven diets with eight replicate pigs per diet. Feces and urine were collected quantitatively with 7-d adaptation and 5-d collection periods. Blood and tissue samples from pigs fed the basal diet and pigs fed diets containing 0.108% supplemental Met were collected on the last day. Results indicated that N retention (%) linearly increased (P < 0.01) as supplemental d-Met or l-Met increased in diets. Based on N retention (%) as a response, the linear slope-ratio regression estimated the bioavailability of d-Met relative to l-Met to be 101% (95% confidence interval: 57%-146%). The villus height and crypt depth in the jejunum were not affected by the Met level or Met source. Total antioxidant capacity or thiobarbituric acid reactive substance concentrations in plasma or tissue samples from pigs fed the control diet or diets containing 0.108% supplemental d-Met or l-Met were not different. Abundance of mRNA for some AA transporters analyzed in intestinal mucosa of pigs also did not differ. Therefore, it is concluded that d-Met and l-Met are equally bioavailable for weanling pigs.

Inclusion of dicopper oxide instead of copper sulfate in diets for growing-finishing pigs results in greater final body weight and bone mineralization, but reduced accumulation of copper in the liver.

An experiment was conducted to test the hypothesis that inclusion of Cu oxide (Cu2O) in diets for growing-finishing pigs improves body weight (BW) and bone mineralization, and reduces accumulation of Cu in the liver compared with pigs fed diets containing Cu sulfate (CuSO4). Two hundred growing pigs (initial BW: 11.5 ± 0.98 kg) were allotted to a randomized complete block design with 2 blocks of 100 pigs, 5 dietary treatments, 5 pigs per pen, and a total of 8 pens per treatment. Treatments included the negative control (NC) diet that contained 20 mg Cu/kg, and 4 diets in which 125 or 250 mg Cu/kg from CuSO4 or Cu2O were added to the NC diet. The experiment was divided into 4 phases and concluded when pigs reached market weight. Pig weights were recorded on day 1 and at the end of each phase and feed provisions were recorded throughout the experiment. On the last day of phases 1 and 4, 1 pig per pen was sacrificed to obtain samples of liver and spleen tissue, and the right metacarpal was collected. Results indicated that pigs fed diets containing 250 mg Cu/kg from CuSO4 had greater BW at the end of phases 1 and 2 than pigs fed NC diets. Pigs fed diets containing 250 mg Cu/kg from Cu2O had greater (P < 0.05) BW at the end of phases 1, 2, 3, and 4 compared with pigs fed NC diets, and these pigs also had greater BW at the end of phases 3 and 4 than pigs fed all other diets. Pigs fed the diets with 250 mg Cu/kg tended to have greater (P < 0.10) feed intake than pigs fed the NC diet at the end of phase 2, and for the overall experimental period, pigs fed diets containing 250 mg Cu/kg from Cu2O had greater (P < 0.05) feed intake than pigs on all other treatments. However, no differences in gain:feed ratio were observed among treatments. Copper accumulation in liver and spleen increased with Cu dose, but at the end of phase 1, pigs fed 250 mg Cu/kg from CuSO4 had greater (P < 0.05) Cu concentration in liver and spleen than pigs fed 250 mg Cu/kg from Cu2O. Pigs fed diets containing 250 mg Cu/kg from Cu2O had greater (P < 0.05) quantities of bone ash and greater (P < 0.05) concentrations of Ca, P, and Cu in bone ash than pigs fed NC diets or the 2 diets containing CuSO4, but Zn concentration in bone ash was less (P < 0.05) in pigs fed diets containing 250 mg Cu/kg from Cu2O. To conclude, supplementing diets for growing pigs with Cu2O improves growth performance and bone mineralization with less Cu accumulation in liver compared with pigs fed diets containing CuSO4.

Addition of hydrochloric acid to collection bags or collection containers did not change basal endogenous losses or ileal digestibility of amino acid in corn, soybean meal, or wheat middlings fed to growing pigs.

OBJECTIVE: The hypothesis was that apparent ileal digestibility (AID), basal endogenous losses, and standardized ileal digestibility (SID) of amino acids (AA) are not affected by adding acid to collection containers or bags used to collect ileal digesta from pigs. METHODS: Twenty-four growing barrows (initial body weight: 77.8±4.5 kg) that were fitted with a T-cannula in the distal ileum were fed diets for three 7-d periods. An N-free diet and 3 diets containing corn, soybean meal, or wheat middlings as the sole source of AA were used. Within each period, each of the 4 diets were fed to 6 pigs. Among the 6 pigs, digesta from 3 pigs were collected in bags containing no HCl, whereas 40 mL of 3 N HCl was included in the bags used to collect digesta from the remaining 3 pigs. Every other bag collected from each pig was emptied into a container without adding HCl, whereas the remaining bags were added to a container along with 40 mL of 3 N HCl for each bag. All digesta were stored at -20°C immediately after collection. Data were analyzed using a model that included feed ingredient, HCl in bags, HCl in containers, and all 2-way and 3-way interactions as fixed effects. No 3-way interactions were significant, and data were, therefore, reanalyzed independently for each diet as a 2×2 factorial. RESULTS: There were no interactions between adding HCl to collection bags and to containers, and no effects of adding HCl to collection bags or containers for AID, basal endogenous losses, or SID of most AA were observed. CONCLUSION: It is not necessary to add acid to digesta collection bags or collection containers if ileal digesta are stored at -20°C immediately after collection.

Dietary Organic Acids Modulate Gut Microbiota and Improve Growth Performance of Nursery Pigs.

Feed additives have been suggested to improve animal growth performance through modulating the gut microbiota. The hypothesis of this study was that the combination of two organic acids would exert synergistic effects on the growth performance and gut microbiota of weaning pigs. To test this hypothesis, we followed 398 weaning pigs from two university experiment stations (University of Illinois at Urbana-Champaign (UIUC) and University of Arkansas (UA)) to determine the effects of increasing levels (0%, 0.035%, 0.070%, and 0.105%) of sodium butyrate combined with 0.5% benzoic acid on the growth performance of nursery pigs. At the UA, an additional negative control diet was included and the gut microbiota analysis was carried out. At both universities, increasing levels of sodium butyrate in a diet containing 0.5% benzoic acid improved growth performance, which reached a plateau in the pigs fed 0.035% (SBA0.035) or 0.070% (SBA0.070) butyrate. Gut microbiota analysis revealed that pigs fed the SBA0.035 diet had more diverse microbiota and contained more potentially beneficial bacteria such as Oscillospira, Blautia, and Turicibacter and reduced levels of Veillonella and Sarcina. Results of the present study indicated that the inclusion of sodium butyrate at moderate levels in a diet containing 0.5% benzoic acid improved growth performance of weaning pigs and established potential health benefits on gut microbiota.

Management and Feeding Strategies in Early Life to Increase Piglet Performance and Welfare around Weaning: A Review.

The performance of piglets in nurseries may vary depending on body weight, age at weaning, management, and pathogenic load in the pig facilities. The early events in a pig's life are very important and may have long lasting consequences, since growth lag involves a significant cost to the system due to reduced market weights and increased barn occupancy. The present review evidences that there are several strategies that can be used to improve the performance and welfare of pigs at weaning. A complex set of early management and dietary strategies have been explored in sows and suckling piglets for achieving optimum and efficient growth of piglets after weaning. The management strategies studied to improve development and animal welfare include: (1) improving sow housing during gestation, (2) reducing pain during farrowing, (3) facilitating an early and sufficient colostrum intake, (4) promoting an early social interaction between litters, and (5) providing complementary feed during lactation. Dietary strategies for sows and suckling piglets aim to: (1) enhance fetal growth (arginine, folate, betaine, vitamin B12, carnitine, chromium, and zinc), (2) increase colostrum and milk production (DL-methionine, DL-2-hydroxy-4-methylthiobutanoic acid, arginine, L-carnitine, tryptophan, valine, vitamin E, and phytogenic actives), (3) modulate sows' oxidative and inflammation status (polyunsaturated fatty acids, vitamin E, selenium, phytogenic actives, and spray dried plasma), (4) allow early microbial colonization (probiotics), or (5) supply conditionally essential nutrients (nucleotides, glutamate, glutamine, threonine, and tryptophan).

Effects of a novel E. coli phytase expressed in Pseudomonas fluorescens on growth, bone mineralization, and nutrient digestibility in pigs fed corn-soybean meal diets.

Two studies were conducted to determine the effects of a novel Escherichia coli phytase expressed in Pseudomonas fluorescens on growth performance, bone mineralization, and nutrient digestibility in pigs fed corn-soybean meal diets. In experiment 1, 160 nursery pigs (9.79 ± 1.22 kg) were randomly allotted to one of four treatments with 10 pens per treatment and four pigs per pen. Phase I and phase II diets were provided from d 0 to d 14 and d 14 to d 28, respectively. Treatments included: positive control (PC) with all nutrients meeting requirements; negative control (NC) with standardized total tract digestible (STTD) P reduced by 0.15% and 0.14% compared with PC in phase I and phase II, respectively; and NC diets containing 250 or 500 units of phytase (FTU) per kilogram. Results demonstrated that pigs fed PC had greater (P < 0.01) ADG and G:F for the overall experimental period, and greater (P < 0.01) bone ash and P concentrations, compared with pigs fed NC or diets with phytase supplementation. Pigs fed diets containing phytase had greater (P < 0.01) ADG and G:F for the overall experimental period compared with pigs fed the NC diet without phytase, and bone ash and P weights were increased (P < 0.01) as well. In experiment 2, 63 growing barrows (56.25 ± 2.54 kg) were blocked by BW and randomly allotted to one of seven treatments with nine pens per treatment and one pig per pen. A basal corn-soybean meal diet was formulated to meet nutrient requirements for growing pigs with the exception that STTD P was reduced by 0.18% compared with the requirement, and Ca was included to achieve a Ca:STTD P ratio of 2.15. Six additional diets were formulated by adding 250, 500, 750, 1,000, 1,500, or 2,000 FTU/kg of phytase to the basal diet. Pigs were fed experimental diets for 12 d with 7 d of adaptation and 5 d of fecal sample collection. Results indicated that there was a linear (P < 0.01) increase in apparent total tract digestibility of ash and ether extract, and STTD of Ca and P also increased (linear, P < 0.05) in response to increasing doses of phytase. Increasing phytase levels in the diets resulted in increase (quadratic, P < 0.05) in apparent ileal digestibility of Arg, His, Ile, Lys, Trp, Asp, and Glu. In conclusion, the novel E. coli phytase was effective in increasing growth performance, bone mineralization, and Ca and P digestibility in pigs fed corn-soybean meal-based diets. Results also indicated that this phytase had the potential to enhance the digestibility of fat and certain AA.

Inclusion of the direct-fed microbial Clostridium butyricum in diets for weanling pigs increases growth performance and tends to increase villus height and crypt depth, but does not change intestinal microbial abundance.

An experiment was conducted to test the hypothesis that inclusion of the direct fed microbial Clostridium butyricum in diets for weanling pigs will improve growth performance, systemic immune function, microbiota composition, and gut morphology in weaned pigs. A total of 275 newly weaned pigs (20 ± 2 d of age) with an average initial BW of 6.4 ± 0.8 kg were allotted to a randomized complete block design with 11 pens per treatment. Diets included a positive control diet containing Carbadox, a negative control diet without Carbadox, and three treatment diets in which 1,250 × 108 cfu/kg, 2,500 × 108 cfu/kg, or 3,500 × 108 cfu/kg of C. butyricum was added to the negative control diet. A two-phase feeding program was used (phase 1, 14 d; phase 2, 21 d). At the conclusion of the experiment (day 35), a blood sample was collected from one pig per pen (11 pigs per treatment) and this pig was then euthanized and digesta and tissues samples were collected. Results indicated that for the overall phase, pigs fed the positive control diet had greater (P < 0.05) ADG and ADFI and tended (P = 0.064) to have greater final BW than pigs fed the negative control diet. The ADG and G:F increased and then decreased as increasing doses of C. butyricum were included in the diet (quadratic, P < 0.05). The concentration of tumor necrosis factor-α was less (P < 0.05) in pigs fed the positive control diet compared with pigs fed the negative control diet or diets containing C. butyricum. Crypt depth tended (P = 0.08) to be less in pigs fed the negative control diet compared with pigs fed the positive control diet and villus height tended to increase as the doses of C. butyricum increased in the diets (quadratic, P = 0.08). Villus height also tended (P = 0.084) to be greater in pigs fed diets containing C. butyricum compared with pigs fed the positive control diet. Crypt depth increased as the dose of C. butyricum increased (quadratic, P < 0.05) and villus width at the bottom tended to increase (linear, P = 0.072) as the dose of C. butyricum increased in the diet. Alpha and beta diversity indices of ileal and colonic microbiota were not affected by diet. In conclusion, addition of 1,250 × 108 cfu/kg of C. butyricum, but not greater levels, to diets fed to weanling pigs increased growth performance and tended to increase villus height and crypt depth, but changes in the abundance of intestinal microbiota were not observed.

Effects of a novel corn-expressed E. coli phytase on digestibility of calcium and phosphorous, growth performance, and bone ash in young growing pigs1.

Two experiments were conducted to test the hypothesis that a corn-expressed phytase increases growth performance, bone measurements, and nutrient digestibility by young growing pigs, if added to diets that are deficient in Ca and P. In Exp. 1, 60 pigs (initial BW: 10.78 ± 0.67 kg) were randomly allotted to 6 dietary treatments that included a positive control diet (PC; 0.70% total Ca and 0.60% total P) and a negative control diet (NC; 0.50% total Ca and 0.42% total P). Four additional diets were formulated by supplementing the NC diet with 250, 500, 1,000, or 1,500 phytase units (FTU)/kg. Diets were fed for 28 d and the individual BW of pigs on days 1 and 28 were recorded. Fecal samples were collected from days 25 to 27 to calculate apparent total tract digestibility (ATTD) of Ca and P. On the last day of the experiment, all pigs were euthanized, and the left femur was removed and analyzed for ash, Ca, and P. Results indicated that growth performance, ATTD of Ca and P, and bone ash measurements were reduced (P < 0.05) in NC fed pigs compared with PC fed pigs. However, growth performance, ATTD of Ca and P, and bone ash measurements were improved (linear and quadratic, P < 0.05) by including increasing concentrations of phytase to the NC diet. In Exp. 2, experimental procedures were similar to those used in Exp. 1. Forty-eight pigs (initial BW: 11.15 ± 0.85 kg) were randomly allotted to 6 dietary treatments in a 28-d experiment. Treatments included a PC diet, an NC diet, and 4 diets in which 500 or 1,000 FTU/kg of either the corn-expressed phytase or a commercial microbial phytase were added to the NC diet. Pigs fed the NC diet had reduced (P < 0.01) final BW, ADG, G:F, and bone ash concentrations compared with pigs fed the PC diet. When 500 FTU/kg phytase was fed, no differences were observed in growth performance or bone ash measurements between phytase sources, and there were no differences in growth performance among pigs fed 1,000 FTU/kg of either phytase source or the PC diet. However, regardless of concentration or source of phytase, pigs fed the PC diet had greater (P < 0.001) amount of bone ash, bone Ca, and bone P compared with pigs fed phytase diets. In conclusion, the corn-expressed phytase is effective in improving growth performance, Ca and P digestibility, and bone measurements in pigs fed diets that are deficient in Ca and P.

Effects of Bacillus amyloliquefaciens and Bacillus subtilis on ileal digestibility of AA and total tract digestibility of CP and gross energy in diets fed to growing pigs.

The objective of this experiment was to test the hypothesis that the apparent ileal digestibility (AID) of AA, CP, and GE, the apparent total tract digestibility (ATTD) of CP and GE, and the apparent hindgut digestibility of CP and GE by growing pigs may be improved by supplementing diets with two direct-fed microbials (DFM) containing different Bacillus strains. Twenty-four growing barrows (initial BW: 22.69 ± 1.48 kg) that had a T-cannula installed in the distal ileum were individually housed and randomly allotted to a three diet, three period design with 24 pigs and three 21-d periods. There were eight pigs per diet in each period for a total of 24 observations per diet. Three diets that were based on corn, soybean meal, and distillers dried grains with solubles were formulated. The control diet contained no DFM, but two additional diets contained two different Bacillus strains (Bacillus amyloliquefaciens or Bacillus subtilis). Feed was provided in mash form in two daily meals at 0800 and 1600 hours. The initial 12 d of each period was the adaptation period to the diet. Fecal and urine samples were collected from days 13 to 18, and ileal digesta were collected for 8 h on days 20 and 21. Results indicated that there were no differences among diets in ATTD of CP, but the AID of CP was reduced (P < 0.05) for the B. subtilis diet compared with control and B. amyloliquefaciens diets. Therefore, the apparent hindgut digestibility of CP was greater (P < 0.005) in pigs fed the B. subtilis diet compared with the other diets. The AID of total indispensable, total dispensable, and total AA was greater (P < 0.05) in the B. amyloliquefaciens diet compared with the control diet. There were no differences among diets in ATTD of GE, but the AID of GE was greater for the B. amyloliquefaciens diet than for the control and the B. subtilis diets (P < 0.001). Therefore, the apparent hindgut digestibility of GE was less (P < 0.05) in the B. amyloliquefaciens diet compared with the other diets. The DE (DM basis) for the B. subtilis diet was greater (P < 0.05) compared with the control and the B. amyloliquefaciens diets. In conclusion, supplementation of Bacillus spp. to diets fed to growing pigs may increase the AID of AA and GE, but there appears to be differences among strains of Bacillus spp. in their impact on AA and energy digestibility.

Effects of distillers dried grains with solubles on amino acid digestibility, growth performance, and carcass characteristics of growing pigs.

Two experiments were conducted to compare the standardized ileal digestibility (SID) of AA by growing pigs in European distillers dried grains with solubles (DDGS) produced from wheat, maize, or wheat-maize mixtures and to test the effect of increasing the inclusion levels of wheat DDGS on growth performance of growing-finishing pigs fed diets balanced for NE and SID Lys. In Exp. 1, 12 barrows (initial BW: 23.0 ± 2.2 kg) were surgically equipped with a T-cannula in the distal ileum and randomly allotted to a replicated 6 × 6 Latin square design with six diets and six periods. Five sources of European DDGS were used: wheat DDGS from 2011, wheat DDGS from 2012, wheat-80 DDGS (80% wheat and 20% maize), wheat-70 DDGS (70% wheat and 30% maize), and maize DDGS. Each diet contained one source of DDGS as the sole source of AA and an N-free diet was used to determine basal endogenous losses of AA. Results indicated that the SID of CP was greater (P < 0.05) in maize DDGS compared with wheat DDGS from 2011, wheat DDGS from 2012, and wheat-70 DDGS. The SID of all indispensable AA except Trp was also greater (P < 0.05) in maize DDGS compared with all other DDGS sources used in this experiment. For Trp, the SID in wheat-80 DDGS, wheat DDGS from 2011, and wheat DDGS from 2012 were not different from maize DDGS, but were greater (P < 0.05) than in wheat-70 DDGS. The SID for all indispensable AA except Ile and Trp in wheat-70 DDGS were not different from the values calculated for wheat DDGS from 2011 and wheat DDGS from 2012, and no differences between SID values for AA in wheat DDGS from 2011 and wheat DDGS from 2012 were observed. In Exp. 2, 36 growing pigs (initial BW: 38.3 ± 1.97 kg) were randomly allotted to one of four dietary treatments (one pig/pen and nine replicate pigs/treatment) in a 2-phase feeding program (35 to 65, and 35 to 105 kg BW). The four dietary treatments included diets containing 0%, 10%, 20%, or 30% wheat DDGS. Results indicated that there was no effect of wheat DDGS on pig growth performance or carcass quality. However, addition of wheat DDGS increased linearly (P < 0.015) the indole concentration in the carcasses of the pigs. In conclusion, the SID of AA in maize DDGS produced in Europe is greater than in European wheat DDGS and DDGS produced from mixtures of wheat and maize, but inclusion of 30% wheat DDGS in diets fed to growing-finishing pigs did not affect growth performance or carcass quality.