Effect of dietary inulin and phytase on mineral digestibility and tissue retention in weanling and growing swine

Dietary iron or inulin supplementation alters iron status, growth performance, intramuscular fat and meat quality in finisher pigs

Forty LW × L pigs (20 boars and 20 gilts) (51.1 ± 0.41 kg) were allocated to a 2 × 2 × 2 factorial design with the respective factors being supplemental organic iron (Fe, 0 and 500 mg/kg), inulin (In, 0 and 50 g/kg) and sex (boars and gilts). After 5 weeks the animals were transported to an abattoir before slaughter and collection of samples. Serum iron was increased by supplemental Fe (28.4 v. 30.9 μmol/L, P = 0.05), although there was an interaction (P = 0.03) such that pigs fed diets with In had lower serum Fe concentrations than those without In (26.8 v. 32.3 μmol/L). Boars had lower (P < 0.01) haemoglobin (116 vs 125), haematocrit (36.7 v. 39.7%) and erythrocyte (6.6 v. 7.1 × 106/mL) concentrations than gilts. Dietary In increased liveweight gain (795 v. 869 g/d, P < 0.02) and carcass weight (62.9 v. 65.2 kg, P < 0.02). Dietary Fe or In supplementation did not improve muscle Longissimus thoracis et lumborum (LTL) total Fe concentration (P > 0.05). Muscle non-heme Fe concentration was higher in Fe-supplemented pigs (P < 0.04) and gilts (P < 0.05) than their counterparts. Muscle heme Fe concentration was greater (3.04 vs 2.51, P < 0.05) in boars than in gilts. The LTL marbling score was greater (P < 0.01) for In-supplemented pigs, and the response was more notable when Fe and In were fed together. These data show that dietary supplementation of Fe increased serum Fe and muscle non-heme Fe concentrations. Supplementation of In at 5% in the diet of finisher pigs improved liveweight gain and the marbling score of pork.

Donor age and body weight determine the effects of fecal microbiota transplantation on growth performance, and fecal microbiota development in recipient pigs

Background

The application of fecal microbiota transplantation (FMT) to improve swine growth performance has been sporadically studied. Most of these studies used a single microbiota source and thus the effect of donor characteristics on recipient pigs’ fecal microbiota development and growth performance is largely unknown.

Results

In this study, we collected feces from six donors with heavy (H) or light (L) body weight and different ages (d 42, nursery; d 96, growing; and d 170, finisher) to evaluate their effects on the growth performance and fecal microbiota development of recipient pigs. Generally, recipients that received two doses of FMT from nursery and finisher stages donor at weaning (21 ± 2 days of age) inherited the donor’s growth pattern, while the pigs gavaged with grower stage material exerted a numerically greater weight gain than the control pigs regardless of donor BW. FMT from heavier donors (NH, GH, and FH) led to the recipients to have numerically increased growth compared to their lighter counterparts (NL, GL, and FL, respectively) throughout the growing and most finishing stages. This benefit could be attributed to the enrichment of ASV25 Faecalibacterium, ASV61 Faecalibacterium, ASV438 Coriobacteriaceae_unclassified, ASV144 Bulleidia, and ASV129 Oribacterium and decrease of ASV13 Escherichia during nursery stage. Fecal microbiota transplantation from growing and finishing donors influenced the microbial community significantly in recipient pigs during the nursery stage. FMT of older donors’ gut microbiota expedited recipients’ microbiota maturity on d 35 and 49, indicated by increased estimated microbiota ages. The age-associated bacterial taxa included ASV206 Ruminococcaceae, ASV211 Butyrivibrio, ASV416 Bacteroides, ASV2 Streptococcus, and ASV291 Veillonellaceae. The body weight differences between GL and GH pigs on d 104 were associated with the increased synthesis of the essential amino acid, lysine and methionine, mixed acid fermentation, expedited glycolysis, and sucrose/galactose degradation.

Conclusions

Overall, our study provided insights into how donor age and body weight affect FMT outcomes regarding growth performance, microbiota community shifts, and lower GI tract metabolic potentials. This study also provided guidance to select qualified donors for future fecal microbiota transplantation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40104-022-00696-1.

Effects of adding high-dosing Aspergillus oryzae phytase to corn-wheat-soybean meal-based basal diet on growth performance, nutrient digestibility, faecal gas emission, carcass traits and meat quality in growing-finishing pigs

This study tests the effects of supplementation of high-dosing Aspergillus oryzae phytase into the corn-wheat-soybean meal (SBM)-based basal diet on growth performance, nutrient digestibility, faecal gas emission, carcass traits and meat quality in growing-finishing pigs (29.73-110.86 kg live weight; 70-day-old to 166-day-old). A total of 56 crossbred pigs [(Landrace × Yorkshire) × Duroc] were divided into two dietary groups for a 96-day experiment (growing period, days 0-42; finishing period, days 43-96) with a completely randomized block design. There were seven replicate pens in each dietary group, and each pen has four pigs (two barrows and two gilts). The dietary treatments consisted of a corn-wheat-SBM-based nutrient sufficient basal diet or the basal diet supplemented with 1500 FTU/kg A. oryzae phytase. One phytase unit (FTU) was defined as the amount of enzyme that catalyses the release of one micromole phosphate from phytate/min at 37°C and pH 5.5. Higher average daily gain and lower feed conversion ratio were observed in growing-finishing pigs consuming a high-dosing A. oryzae phytase supplementing diet during days 0-42 and 0-96. Supplementing high-dosing A. oryzae phytase to the diet of growing-finishing pigs increased apparent total tract digestibility of phosphorus on days 42 and 96. Moreover, growing-finishing pigs fed the diet supplemented with high-dosing A. oryzae phytase had higher carcass back-fat thickness than those fed the control diet. However, the faecal gas emission and meat quality were not affected by high-dosing A. oryzae phytase supplementation. In conclusion, dietary supplementation of high-dosing A. oryzae phytase (1500 FTU/kg) had beneficial effects on the growth performance, apparent phosphorus digestibility and carcass back-fat thickness in growing-finishing pigs.

Effects of Exogenous 6-Phytase (EC 3.1.3.26) Supplementation on Performance, Calcium and Phosphorous Digestibility, and Bone Mineralisation and Density in Weaned Piglets

Phosphorus (P) is an essential mineral for growing piglets, which is poorly accessible in vegetable feedstuffs as it is stored as phytates. Thus, phytase supplementation is essential to increase P availability. Two experiments were conducted to evaluate a novel 6-phytase (EC 3.1.3.26) in weaned pigs fed low-P diets. In each experiment, one hundred and twenty piglets were fed a positive control (PC; adequate in Ca and P), a negative control (NC; limiting in Ca and P), or NC supplemented with 125, 250, or 500 FTU/kg of phytase (NC125, NC250, and NC500, respectively). P content was lower in diets of Experiment 1 than diets of Experiment 2. In Experiment 1, piglets offered PC or phytase diets had higher growth and efficiency compared with NC diets. In Experiment 2, similar effects were obtained, but the effects were less significant. In both experiments, P and Ca ATTD and bone density were significantly increased with phytase supplementation. Moreover, PC and NC500 had higher P concentrations and lower alkaline phosphatase activity in plasma than NC. To conclude, supplementation with the new 6-phytase at doses up to 500 FTU/kg enhanced P utilization, growth performance, and bone density in piglets fed P-limiting diets.

Effects of supplementation of high-dosing Trichoderma reesei phytase in the corn-wheat-soybean meal-based diets on growth performance, nutrient digestibility, carcass traits, faecal gas emission, and meat quality in growing-finishing pigs

We conduct this study to investigate the effects of corn-wheat-soybean meal (SBM)-based diet supplemented with high-dosing Trichoderma reesei phytase on the growth performance, nutrient digestibility, carcass traits, faecal gas emission and meat quality in growing-finishing pigs (29.71-110.58 kg live weight; 70-day-old to 166-day-old). A total of 56 crossbred pigs [(Landrace × Yorkshire) × Duroc] were used in 96-day experiment with a completely randomized block design. The growing period was from day 0 to 42, and the finishing period was from day 43 to 96. Pigs were randomly allocated to one of two treatments with seven replicate pens and four pigs (two barrows and two gilts) per pen and fed corn-wheat-SBM-based nutrient adequate basal diet or the basal diet supplemented with 1500 FTU/kg diet Trichoderma reesei phytase. One phytase unit (FTU) was defined as the amount of enzyme that catalyses the release of one micromole phosphate from phytate per minute at 37°C and pH 5.5. Dietary supplement with Trichoderma reesei phytase had increased body weight on day 96 and average daily gain in days 0-96. Moreover, high apparent total tract digestibility (ATTD) of phosphorus (P) was observed in pigs fed with Trichoderma reesei phytase. However, the carcass traits, faecal gas emission and meat quality of pigs were unaffected by Trichoderma reesei phytase supplementation. In conclusion, supplementation of high-dosing Trichoderma reesei phytase (1500 FTU/kg diet) in the corn-wheat-SBM-based nutrient adequate basal diet increased body weight and the ATTD of P, while no adverse effects were observed on the production characteristics.

Diet supplemented either with dried chicory root or chicory inulin significantly influence kidney and liver mineral content and antioxidative capacity in growing pigs

According to the Regulation No. 1831/2003 of the European Parliament and European Union Council, the use of antibiotics as a dietary supplements has been prohibited. It seems that the administration of prebiotics, instead of antibiotics, into the pig's diet, may regulate the intestinal microbiota and has a long-term health-related impact on the host. Inulin-type fructans can stimulate mineral absorption from the gut. Additionally, it may regulate energy metabolism and activate enzymatic mechanisms preventing oxidative stress. The goal of the present study was to estimate the influence of dietary supplementation with dried chicory root or native chicory inulin on 1) liver histology; 2) liver and kidney lipid metabolism indices, activity of selected enzymes, concentration of macro- and micronutrients and heavy metals; 3) blood plasma, liver and kidney oxidative stress biomarkers and 4) blood plasma water-electrolyte homeostasis indices in growing pigs. The nutritional study was conducted on 24 piglets assigned to 3 dietary groups (n = 8): control (C) fed a basal diet and two experimental groups receiving basal diet supplemented with 2% of inulin (IN) either 4% of dried chicory root (CR). The animals were fed with a group-specific diets for 40 days and then subjected to euthanasia. Subsequently, blood, liver and kidney samples were harvested for further processing. In the control and experimental groups, no apparent morphological abnormalities in the liver tissues were seen. The percent of periodic acid Schiff positive glycogen liver cells was significantly lower in the CR group as compared to C and IN groups (P < 0.001). Chicory root supplementation improved blood plasma prooxidative-antioxidative balance - PAB (P < 0.001) and liver PAB (P < 0.01) and thiobarbituric acid reactive substances - thiobarbituric acid-reactive substances (P < 0.05). Feeding the CR diet increased calcium (P < 0.001) and potassium (P < 0.05) and decreased cadmium (P ≥ 0.05) content in the liver when compared to the C group. Administration of the CR and IN diets increased selenium (Se) and sodium concentrations, whereas decreased zinc content both in the liver (P < 0.01; P < 0.05 and P < 0.05, respectively) and in the kidney (P < 0.01; P < 0.001 and P < 0.001, respectively) of pigs. Additionally, a higher concentration of lead (P < 0.05) was observed in the kidney of pigs fed the CR diet. In conclusion, both dietary supplements had a potential to significantly improve the Se status and oxidoreductive homeostasis in growing pigs.

Supplemental Microalgal Iron Helps Replete Blood Hemoglobin in Moderately Anemic Mice Fed a Rice-Based Diet

Iron deficiency anemia affects 1.2 billion people globally. Our objectives were to determine if (1) supplemental iron extracted from defatted microalgae (Nannochloropsis oceanica, DGM) and (2) a combination of minute amount of plant phytase and inulin could help replete hemoglobin in anemic mice. Mice (7 weeks old) were fed a control diet (6 mg Fe/kg). After 10 weeks, the mice were assigned to three treatments: control, control + DGM iron (Fe-DGM, 39 mg Fe/kg), or control + 1% inulin + 250 units of phytase/kg (INU−PHY, 6 mg Fe/kg). The mice had free access to diets and water for 6 weeks. The Fe-DGM group had elevated blood hemoglobin (p < 0.01) and a two-fold greater (p < 0.0001) liver non-heme iron over the control. Strikingly, the INU-PHY group had 34% greater non-heme iron than the control, despite the same concentrations of iron in their diets. Fe-DGM group had altered (p < 0.05) mRNA levels of hepcidin, divalent metal transporter 1, transferrin and transferrin receptor 1. Iron extracted from defatted microalgae seemed to be effective in alleviating moderate anemia, and INU-PHY enhanced utilization of intrinsic iron present in the rice diet. Our findings may lead to a novel formulation of these ingredients to develop safer and bioavailable iron supplements for iron-deficient populations.

Effects of dietary inclusion of Lactobacillus and inulin on growth performance, gut microbiota, nutrient utilization, and immune parameters in broilers

The effects of dietary Lactobacillus (BCRC 16092) and inulin on growth performance, intestinal microflora, mineral utilization, and tissue mineral contents were evaluated in broilers. The experiment was conducted using 1,152 one-day-old broilers randomly distributed to 9 treatments in a factorial arrangement (3 × 3) using 3 levels of inulin (0, 1, and 2%) and 3 levels of Lactobacillus addition (108, 109, and 1010 CFU/kg). Broilers (1 D of age; 8 replicates per treatments and 16 broilers per replicate) with an initial body weight of 48.36 ± 0.21g were evaluated for 42 D. A 4-D mineral digestibility trial was conducted during the final week of the experiment. The results showed that Lactobacillus supplementation can increase average daily gain and nutrient digestibility and improve feed/gain in broilers (P < 0.05). Moreover, Lactobacillus and inulin supplementation increased the numbers of Lactobacillus and Bifidobacteria, increased serum concentration of IgG and IgA, and decreased the numbers of Escherichia coli and pH in ileum and cecum. The present study demonstrated Lactobacillus and inulin fed to broilers has a positive effect on gut microbiota, growth and nutrient utilization, immune system, and mineral metabolism.

Effect of microbial phytase supplementation on P digestibility in pigs: a meta-analysis

The objectives of this meta-analysis were to determine to which extent phosphorus (P) digestibility and digestible P concentration in pig diets were increased by phytase supplementation and to quantify factors that potentially influence effects of phytase supplementation. A data set with a total of 547 data lines was compiled from 88 experiments published in 74 peer-reviewed papers between 2007 and April 2019. An exponential model was determined as more suitable to describe the response of P digestibility to phytase supplementation than a polynomial model. Phytase supplementation increased P digestibility by 25.6 percentage points (standard error (SE) = 1.54) to a plateau at 64.9% (SE = 1.82). The digestible P concentration was increased by phytase supplementation in the order of 1.01 g/kg (SE = 0.102) to a plateau at 2.62 g/kg (SE = 0.122). Goodness-of-fit criteria were R² = 0.780 and root mean square error = 7.55% for P digestibility, and R² = 0.691 and root mean square error = 0.48 g/kg for digestible P concentration. Consideration of further factors such as mineral P supplementation (yes or no), ad libitum vs. restrictive feeding, mixed diets vs. single feed ingredients, sex and age of pigs did not increase the accuracy of prediction in this data set. Some of these traits exhibited responses, but they likely are artefacts generated through the imbalanced structure of the data set. Effects of dietary total P, phytate (InsP₆), InsP₆-P to total P ratio, and Ca on the effect of supplemented phytase were not quantifiable. The present meta-analysis showed that responses to phytase supplementation can be well predicted although variation in P digestibility and digestible P concentration in the data set was high. Overall, predicted effects of phytase on P digestibility well corresponded to predictions made 25 years ago.

The effect of inulin supply to high-fat diet rich in saturated fatty acids on pork quality and profile of sarcoplasmic protein in meat exudate

The aim of the study was to evaluate the influence of inulin supply to high-fat diet rich in saturated fatty acids (SFA) on pork quality and profile of sarcoplasmic protein in drip loss. At 50 days of age, twenty cross-bred pigs (gilts) were randomly allotted to four groups: the control (C) group fed a standard diet, and three experimental (D1, D2 and D3) groups fed a high-fat diet rich in SFA. Moreover, pigs from the groups D2 and D3 consumed an extra inulin supply (7% of daily feed intake) from 85 to 120 days of age (for 5 weeks) and from 50 to 120 days of age (for 10 weeks) respectively. The addition of inulin to the diet reduced meaty odour and flavour significantly, improved tenderness and overall sensory quality of pork and additionally influenced ultimate pH, L* colour parameter, lactate level and protein content in meat. The diets also affected the profile of sarcoplasmic proteins. Significant effects were observed for the following enzymes-PK/PGI (pyruvate kinase/phosphoglucose isomerase) and ALD (aldolase), which are related to the intensity of post-mortem glycolysis. Presented data indicate that long-term inulin supply to high-fat diet has a positive effect on technological and sensory quality as well as protein profile of pork.

Inulin supplementation reduces the negative effect of a high-fat diet rich in SFA on bone health of growing pigs

Consumption of a high-fat diet, rich in SFA, causes deterioration of bone properties. Some studies suggest that feeding inulin to animals may increase mineral absorption and positively affect bone quality; however, these studies have been carried out only on rodents fed a standard diet. The primary objective of this study was to determine the effect of inulin on bone health of pigs (using it as an animal model for humans) fed a high-fat diet rich in SFA, having an unbalanced ratio of lysine:metabolisable energy. It was hypothesised that inulin reduces the negative effects of such a diet on bone health. At 50 d of age, twenty-one pigs were randomly allotted to three groups: the control (C) group fed a standard diet, and two experimental (T and TI) groups fed a high-fat diet rich in SFA. Moreover, TI pigs consumed an extra inulin supply (7 % of daily feed intake). After 10 weeks, whole-body bone mineral content (P=0·0054) and bone mineral density (P=0·0322) were higher in pigs of groups TI and C compared with those of group T. Femur bone mineral density was highest in pigs in group C, lower in group TI and lowest in group T (P=0·001). Femurs of pigs in groups TI and C had similar, but higher, maximum strength compared with femurs of pigs in group T (P=0·0082). In conclusion, consumption of a high-fat diet rich in SFA adversely affected bone health, but inulin supplementation in such a diet diminishes this negative effect.

Dietary iron concentration influences serum concentrations of manganese in rats consuming organic or inorganic sources of manganese

To determine the effects of dietary Fe concentration on Mn bioavailability in rats fed inorganic or organic Mn sources, fifty-four 22-d-old male rats were randomly assigned and fed a basal diet (2·63 mg Fe/kg) supplemented with 0 (low Fe (L-Fe)), 35 (adequate Fe (A-Fe)) or 175 (high Fe (H-Fe)) mg Fe/kg with 10 mg Mn/kg from MnSO4 or Mn–lysine chelate (MnLys). Tissues were harvested after 21 d of feeding. Serum Mn was greater (P<0·05) in MnLys rats than in MnSO4 rats, and in L-Fe rats than in A-Fe or H-Fe rats. Duodenal divalent metal transporter-1 (DMT1) mRNA was lower (P<0·05) in H-Fe rats than in A-Fe rats for the MnSO4 treatment; however, no significant difference was observed between them for MnLys. Liver DMT1 mRNA abundance was greater (P<0·05) in MnSO4 than in the MnLys group for H-Fe rats. The DMT1 protein in duodenum and liver and ferroportin 1 (FPN1) protein in liver was greater (P<0·05) in the MnSO4 group than in the MnLys group, and in L-Fe rats than in H-Fe rats. Duodenal FPN1 protein was greater (P<0·05) in L-Fe rats than in A-Fe rats for the MnLys treatment, but it was not different between them for the MnSO4 treatment. Results suggest that MnLys increased serum Mn concentration as compared with MnSO4 in rats irrespective of dietary Fe concentration, which was not because of the difference in DMT1 and FPN1 expression in the intestine and liver.

Probiotic L. reuteri treatment prevents bone loss in a menopausal ovariectomized mouse model

Estrogen deficiency is a major risk factor for osteoporosis that is associated with bone inflammation and resorption. Half of women over the age of 50 will experience an osteoporosis related fracture in their lifetime, thus novel therapies are needed to combat post-menopausal bone loss. Recent studies suggest an important role for gut-bone signaling pathways and the microbiota in regulating bone health. Given that the bacterium Lactobacillus reuteri ATCC PTA 6475 (L. reuteri) secretes beneficial immunomodulatory factors, we examined if this candidate probiotic could reduce bone loss associated with estrogen deficiency in an ovariectomized (Ovx) mouse menopausal model. Strikingly, L. reuteri treatment significantly protected Ovx mice from bone loss. Osteoclast bone resorption markers and activators (Trap5 and RANKL) as well as osteoclastogenesis are significantly decreased in L. reuteri-treated mice. Consistent with this, L. reuteri suppressed Ovx-induced increases in bone marrow CD4+ T-lymphocytes (which promote osteoclastogenesis) and directly suppressed osteoclastogenesis in vitro. We also identified that L. reuteri treatment modifies microbial communities in the Ovx mouse gut. Together, our studies demonstrate that L. reuteri treatment suppresses bone resorption and loss associated with estrogen deficiency. Thus, L. reuteri treatment may be a straightforward and cost-effective approach to reduce post-menopausal bone loss.

Effect of mineral source and mannan oligosaccharide supplements on zinc and copper digestibility in growing pigs

This study aimed to compare the effects of organic (proteinate) and inorganic (sulphate) copper (Cu) and zinc (Zn) supplements, in presence or absence of a mannan oligosaccharide (MOS) supplement, on mineral solubility and digestibility in pigs. Twenty-eight barrows (25 ± 4 kg) assigned randomly to four treatment groups were fed a corn-wheat-soya bean meal diet with 10 mg/kg of Cu and 100 mg/kg of Zn supplied as organic or inorganic supplement, and supplemented or not with 0.1% MOS. After an adaptation period, total faeces and urine were collected for a period of 6-7 days. Pigs were then euthanatised and digesta from ileum and caecum were collected. Apparent digestibility was calculated in ileum and caecum using titanium dioxide. The organic mineral supplement improved total (faecal) digestibility and retained/ingested ratio of Cu (p < 0.05) while reducing apparent digestibility of Zn in the ileum (p < 0.05) without effect on total digestibility of Zn. Solubilities of Cu and Zn in liquid fraction of ileum and caecum were not affected by mineral sources. Although MOS supplement increased Cu solubility in the ileum (p < 0.05), it had no effect on digestibility of Zn and Cu in ileum, caecum and faeces, retained/ingested ratio of Zn and Cu, or pH and volatile fatty acid concentration in ileal and caecal digesta. In conclusion, organic mineral supplement improved total digestibility and retained/ingested ratio of Cu in pigs but this cannot be attributed to its solubility in ileal and caecal digesta. The MOS supplement did not interfere with digestibility or dietary utilisation of Zn and Cu in pigs fed above the Zn and Cu requirements.

Digestibility and retention of zinc, copper, manganese, iron, calcium, and phosphorus in pigs fed diets containing inorganic or organic minerals

The objective of this experiment was to measure the apparent total tract digestibility (ATTD) and the retention rate of Zn, Cu, Mn, and Fe in pigs fed either inorganic or organic sources of Zn, Cu, Mn, and Fe. The experimental design was a randomized complete block design with a 2 × 3 factorial arrangement of treatments. There were 2 types of diets (corn grits-based or corn-soybean meal [SBM]-based diets) and 3 micromineral treatments (basal micromineral premix [BMM], inorganic micromineral premix [IMM], and organic micromineral premix [OMM]). The BMM contained no added Zn, Cu, Mn, or Fe; the IMM microminerals were provided as sulfates of Zn, Cu, Mn, and Fe at 40, 50, 20, and 100 mg/kg, respectively. The OMM contained the same levels of the 4 microminerals as IMM, but Zn, Cu, Mn, and Fe in this premix were provided by Zn(2-hydroxy-4-methylthio butanoic acid [HMTBa])2, Cu(HMTBa)2, Mn(HMTBa)2, and FeGly, respectively. Forty-eight barrows (initial BW: 31.1 ± 4.2 kg) were housed individually and allowed ad libitum access to the corn grits diet with BMM for 2 wk. All pigs were then moved to metabolism cages and randomly assigned to 1 of the 6 treatment diets with 8 replicates per diet. Fecal and urine samples were collected for 5 d following a 5-d adaptation period. Compared with corn grits diets, pigs fed corn-SBM diets had greater (P < 0.05) absorption and retention of Zn, Cu, and Mn but less (P < 0.05) ATTD of Zn and Cu. Compared with BMM, supplementation of IMM or OMM increased (P < 0.05) absorption, retention, ATTD, and retention rate of Zn, Cu, Mn, and Fe. Compared with IMM, adding OMM to the corn-SBM diet improved (P < 0.05) the absorption and retention of Cu and Mn and the ATTD of Cu, but these differences were not observed in the corn grits diets (interaction, P < 0.05). In addition, adding OMM to the corn-SBM diet increased (P < 0.05) absorption and retention of Zn and Fe and ATTD of Zn, Mn, and Fe compared with adding IMM to the corn-SBM diet. Supplementation of OMM also increased (P < 0.05) the ATTD and retention rate of P in corn-SBM diets. Results indicate that Zn(HMTBa)2 has greater digestibility and Cu(HMTBa)2 and Mn(HMTBa)2 have greater digestibility and retention rates compared with their inorganic sulfates, if included in a corn-SBM diet. Supplementation of organic microminerals also improves the digestibility of P in a corn-SBM diet.

Digestibility and metabolic utilization of diets containing whole-ear corn silage and their effects on growth and slaughter traits of heavy pigs

The aim was to evaluate 2 levels of dietary inclusion of chopped whole-ear corn silage (WECS) on energy and nutrient utilization, growth, and slaughter performances of heavy pigs. Two in vivo experiments were conducted to determine digestibility and metabolic utilization of WECS using 18 barrows weighing 118 ± 8 kg BW on average, metabolic cages and respiration chambers (Exp. 1), and the effect of WECS on the growth performance and carcass traits on 42 barrows from 90 to 170 kg BW (Exp. 2). In both experiments, pigs were fed 3 experimental diets: a control diet (CON) containing cereal meals, extracted soybean meal, and wheat bran (80%, 9%, and 8% of DM, respectively) and 2 diets containing 15% (15WECS) or 30% WECS (30WECS) on a DM basis in place of wheat bran and corn meal. The diets were prepared daily by mixing the WECS to a suitable compound feed. Feed intake was always restricted to allow a daily DMI of 7.2% BW(0.75) in Exp. 1 and from 8.0% to 6.5% BW(0.75) in Exp. 2. Diets had similar NDF contents (15.2% to 15.8% of DM), and WECS inclusion resulted in a slight reduction in CP content (from 14.0% to 13.6% of DM) and a considerable decrease in P content (from 0.47% to 0.30% of DM). Digestibility of OM, CP, and fat was similar among diets, whereas P digestibility was lower (P < 0.05) for the 30WECS diet (33.5%) in comparison with the CON and 15WECS diets (45.5% and 44.1%, respectively). Nitrogen lost in feces and urine and N retained were not different among diets, whereas P retained decreased with the increase of WECS (5.4, 3.7, and 2.2 g/d for the CON, 15WECS, and 30WECS diets, respectively; P < 0.05). No difference among diets was observed for energy balance. The WECS contained 13.48 MJ ME and 9.39 MJ NE/kg DM. In Exp. 2, feed intake was not depressed by WECS inclusion, and the ADG for the whole experiment was not different among dietary treatments (from 737 to 774 g/d). Fecal pH was lower (P < 0.05) for the WECS diets than the control diet (7.10 and 7.00 vs. 7.40) and for the sampling at 150 kg BW than that at 130 and 110 kg BW (6.96 vs. 7.29 and 7.24). At slaughter, lean percentage in the carcass was lower in the 30WECS diet than those of the other 2 diets (46.8% vs. 48.3% and 48.6%, P = 0.05). The overall experimental data obtained in both trials indicate that substitution of wheat bran and corn meal for WECS (up to 30% of DM) does not affect, with the exception of P utilization and carcass leanness, energy and nutrient utilization and performance of heavy pigs in the last phase of growing.

Evaluating the NRC levels of Cu, Fe, Mn, and Zn using organic and inorganic mineral sources for grower-finisher swine

The dietary effects of Cu, Fe, Mn, and Zn levels, and the addition of Zn and Fe to a nonfortified, micromineral basal diet were evaluated in grower-finisher pigs. Growth, feed efficiency, hematology, carcass characteristics, and loin quality were assessed in growing-finishing pigs (n = 222; initial BW = 24 kg). Corn-soybean meal diets fortified with limestone and dicalcium phosphate with added phytase constituted the basal diets. A study was conducted with 6 dietary treatments and 7 replicates in a randomized complete block design. Treatments consisted of: 1) basal diet without added Cu, Fe, Mn, and Zn microminerals, 2) basal + 50% NRC Cu, Fe, Mn, and Zn requirements, 3) basal + 100% NRC Cu, Fe, Mn, and Zn requirements, 4) basal + 25 mg Zn/kg, 5) basal + 50 mg Zn/kg, and 6) basal + 50 mg Fe/kg. The microminerals were added as an organic mineral proteinate and all diets incorporated organic Se at 0.3 mg/kg. Diets were fed ad libitum over 3 growth phases. At 55, 80, and 115 kg BW, 3 pigs per pen were bled and hemoglobin (Hb) and percent hematocrit (Hct) were determined. At 115 kg BW, 3 pigs per pen were killed and carcass characteristics and loin quality measurements were determined. The ADG, ADFI, and G:F for each of the 3 dietary phases and overall period were not affected by dietary micromineral treatments. The concentration of Hb and percent Hct did not differ because of the treatment at each of the 3 phases. There were no treatment differences in carcass characteristics (HCW, backfat, or LM area). Loin pH, color (L*, a*, and b*), and drip loss did not differ by dietary treatment. Subjective marbling, color, and firmness scores, and intramuscular fat content of loins did not differ as the micromineral level increased above the 1998 and 2012 NRC requirements. The LM from pigs fed supplemental Fe had greater (P < 0.05) firmness and wetness scores than pigs fed the basal diet. These results indicate that there is sufficient amount of innate microminerals (Cu, Fe, Mn, and Zn) in a typical corn-soybean meal based diet to meet the grower-finisher pig's requirement for growth and hematological measurements. Although there was no detrimental effect by eliminating these microminerals from diets, it would seem that a dietary level of 50% of the NRC requirement for Cu, Fe, Mn, and Zn would be warranted.

Effect of microbial phytase on phytate P degradation and apparent digestibility of total P and Ca throughout the gastrointestinal tract of the growing pig

The effect of a dietary microbial phytase on mineral digestibility throughout the gastrointestinal tract (GIT) of the growing pig was studied. Thirty-two entire male pigs (~22 kg BW) were allocated equally to 4 corn-soybean meal diets. One diet was adequate in total P and Ca, the second diet was deficient in total P and Ca (low-P diet), and the third and fourth diets were the low-P diet with microbial phytase added at 1,107 U/kg or 2,215 U/kg, respectively. Titanium dioxide (3 g/kg) was included in the diets as an indigestible marker. The pigs were fed their respective diets for 42 d. Fecal samples were collected from d 38 to 41 and stomach chyme, terminal jejunal, and terminal ileal digesta samples were collected after euthanasia on d 42. Phytate P degradability and apparent total P and Ca digestibility were determined at the gastric, jejunal, ileal, and total tract levels. Phytate P degradation and apparent total P and Ca digestibility were not significantly different between the 2 microbial phytase inclusion levels. Across both microbial phytase-low-P diets, phytase supplementation increased (P < 0.05) phytate P degradability at the jejunal, ileal, and total tract levels by 101%, 77%, and 10%, respectively, but not at the gastric level. Total tract phytate P degradation was greater (P < 0.05) than ileal phytate P degradation for both the unsupplemented (52% units greater) and phytase-supplemented, low-P (26% units greater) diets. The latter result was not reflected by the apparent total P digestibility estimate, which was not significantly different between the ileal and total tract levels for both the unsupplemented and phytase-supplemented, low-P diets. Consequently, there appeared to be considerable phytate degradation in the hindgut, presumably due to the action of hindgut microbes, but the phytate P released in the hindgut did not appear to be absorbed. Apparent Ca digestibility was not significantly different among jejunal, ileal, and total tract levels for any of the dietary treatments, but apparent Ca digestibility was greater (P < 0.05) for the phytase-supplemented diets compared with the unsupplemented diets. Overall, dietary microbial phytase supplementation led to greater phytate degradation to the end of the jejunum. Because the phytate P released in the hindgut was not absorbed, ileal estimates, rather than total tract estimates, of phytate degradation appear to more accurately reflect P availability.

Effect of dietary calcium and phosphorus levels on the total tract digestibility of innate and supplemental organic and inorganic microminerals in a corn-soybean meal based diet of grower pigs

The effects of Ca and P (CaP) levels and micromineral sources on mineral digestibility were evaluated in growing pigs. Treatments consisted of 2 levels of CaP and 3 trace mineral (TM) treatments arranged as a 2 × 3 factorial in a randomized complete block design with 8 replicates. The CaP levels evaluated were: 1) 0.65% Ca and 0.55% P [standard CaP (Std CaP)], and 2) 1.00% Ca and 0.85% P (High CaP). The TM treatments were: 1) Basal, without supplemental TM, 2) Basal supplemented with organic TM, and 3) Basal supplemented with inorganic TM. Both organic and inorganic TM premixes added 15 mg Cu, 150 mg Fe, 10 mg Mn, 0.3 mg Se, and 140 mg Zn/kg diet. Diets were formulated using corn soybean meal with a Ca to P ratio of 1.18 in both CaP treatments. Barrows with an initial BW of 45 kg were acclimated to stainless steel metabolism crates where diets were fed for 14 d before a 10-d collection period. Pigs within replicates were fed equivalent amounts of feed at 0800 and 1600 h each day with water provided free choice. Total feces, urine, and feed orts were collected daily. Essential macro- and microminerals were analyzed by inductively coupled plasma analysis. Increasing dietary CaP decreased the digestibility of Ca and Zn. Phosphorus digestibility did not change when the P inclusion level increased from 0.55 to 0.85% Ptotal. The High CaP level resulted in a lower urinary excretion of most minerals, particularly Cu (P < 0.05) and Mn (P < 0.05), as dietary CaP level increased but the others were not statistically significant. A summary of the ATTD for each of the experimental variables was statistically analyzed and averaged for the experiment. Although there were few statistical differences with individual minerals, they generally demonstrated a decline in digestibility when the High CaP was fed, averaging a 3% lower digestibility consistently than when the Std CaP level was fed. Organic TM averaged an approximately 5% greater digestibility than the average inorganic microminerals with the difference between minerals within each source relatively consistent. These results indicate that CaP level had the greatest effect on mineral digestibility, organic microminerals had a greater digestibility than inorganic minerals, and the innate microminerals had an average apparent digestibility of 45%.