Replacement of inorganic phosphorus by microbial phytase for young pigs fed on a maize-soyabean-meal diet

A novel consensus bacterial 6-phytase variant improves the responses of laying hens fed an inorganic phosphorus-free diet with reduced energy and nutrients from 23 to 72 wk of age

The objective of this study was to evaluate the effect of a novel consensus bacterial 6-phytase variant (PhyG) on egg productivity, eggshell quality, and body composition of laying hens fed inorganic phosphate-free diets with reduced energy and nutrients from 23 to 72 wk of age. Five treatments were randomly assigned, performing 28 replicates per treatment with 4 hens each, totaling 560 Hy-Line W80 birds. A positive control (PC) feed was formulated to contain adequate levels of energy and nutrients. A negative control (NC) feed was formulated without added inorganic phosphate (0.12% nonphytic phosphorus [nPP]) and reduced in Ca, Na, dig AA, and metabolizable energy in comparison with PC feed. Phytase was supplemented in the NC feed at 0, 300, 600, and 900 FTU/kg of feed. The responses evaluated were performance, egg quality, economic analysis, body composition, and tibia composition. Data were analyzed by a 2-factor (diet and age) repeated measure analysis. Overall, the feed intake, hen-day egg production, egg mass, and egg revenue were reduced by the complete removal of dicalcium phosphate (DCP) (P < 0.05). Supplement phytase in the NC diet elicits a positive response on each one of those variables. Laying hens consuming the NC feed with 900 FTU/kg of phytase produced more eggs per hen-housed compared with the phytase dosages of 300 and 600 FTU/kg. Body composition was not affected by dietary nPP, Ca, Na, dig AA, and energy reductions (P > 0.05). At 72-wk-old, tibia ash was reduced in hens consuming the NC diet vs. PC (P < 0.05) and no difference was observed between hens supplemented with phytase and the PC feed. Margin over feeding cost increased in a dose-dependent manner with phytase supplementation. Supplementation with 900 FTU/kg of phytase is recommended to improve the number of eggs produced per hen-housed and the number of marketable eggs produced through 23 to 72 wk of age, under this dietary setting.

The effects of probiotic and phytase on growth performance, biochemical parameters and antioxidant capacity in broiler chickens

BACKGROUND

Probiotics and phytase are commonly used as dietary supplements in poultry diets. Phytase is involved in the release of phosphorus in plant grain ingredient of poultry feed, while probiotics provide beneficial organisms to the gastrointestinal tract.

OBJECTIVE

The present study was performed to evaluate the effect of both commercial probiotic and phytase on chicken performance and biochemical indices.

METHODS

A total of 300 chicks were divided into 4 groups that fed the basal diet, diet containing probiotic (Protexin®), Phytase (Meriphyze 5000®), and probiotic plus phytase all over the growing period. The growth indices were measured weekly, analysed at the 21 and 42 days of age. At 42 days of age, blood samples were collected from all chickens. The concentration of liver enzymes, lipid profiles and antioxidant status were measured in blood samples.

RESULTS

The results showed that the weight gain and feed intake were significantly higher in chickens received phytase alone or phytase in combination with probiotic. The feed conversion ratio (FCR) significantly lower in all supplemented chickens in comparison with control chickens (p < 0.05). Although the addition of probiotic or phytase to chicken diet showed an extent variation in biochemical and antioxidant indices, the addition of phytase plus probiotic showed a significantly increase of blood total protein (TP), albumin (Alb), glutathione peroxidase (GPx), super oxide dismutase (SOD), catalysis (CAT) and total antioxidant capacity (TAC) level, while decrease triglyceride (TG), cholesterol (CHL), aspartate transferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) and malondialdehyde (MDA) in comparison to control chickens. The supplementation of chicken diet with probiotic, phytase or probiotic plus phytase did not effect on low-density lipoprotein (LDL) and high-density lipoprotein (HDL).

CONCLUSIONS

The simultaneous supplementation of probiotics and phytases seems to have a positive effect on growth indices in broilers, but they can cause changes in the serum biochemical profile, which sometimes lead to interference and do not always act synergistically.

Use of fixed calcium to phosphorus ratios in experimental diets may create bias in phytase efficacy responses in swine

The objective of this study was to investigate the effects of two dietary total Ca/P ratios on available P release by phytase, measured using growth performance and bone mineralization with 528 barrows and gilts according to a randomized complete block design. Three were 11 diets in a factorial of 2 by 4 plus 3, including 3 reference diets consisting of 0.25% (control), 0.70%, or 1.15% monocalcium phosphate (MCP) and 8 diets from combining 4 phytase doses (500, 1,000, 2,000, and 3,000 FYT/kg) with 0.25% MCP and 2 dietary Ca/P ratios (1.05 and 1.20). Each diet was fed to 6 pens of 8 pigs. All diets contained 3 g/kg TiO₂, and fecal samples were collected from each pen on d 13–15 of trial. At the end of trial, one pig per pen was sacrificed to collect a tibia and urine in the bladder. The results showed that MCP improved growth performance linearly (P < 0.01), whereas both a linear and quadratic response was observed with the addition of phytase. The MCP increased the percent bone ash and weights of bone ash, Ca, and P linearly (P < 0.01). At both Ca/P ratios, increasing supplementation of phytase increased the percent bone ash and weights of bone ash, Ca, and P both linearly and quadratically (P < 0.05). Both MCP and phytase significantly increased digestibility of Ca and P as well as digestible Ca and P in diets and reduced the digestible Ca/P ratio. The dietary Ca/P ratio of 1.20 resulted in poorer feed utilization efficiency, more digestible Ca, greater percent bone ash, Ca, and P and heavier weights of bone Ca and P than the ratio of 1.05 (P < 0.05). The ratio of 1.20 elicited numerically higher available P release values from phytase, with percent bone ash and bone P weight as the response variables, but significantly lower values with gain:feed. The urinary concentration of Ca increased linearly (P < 0.01) with increasing digestible Ca/P ratios whilst urinary concentration of P decreased quadratically (P < 0.01). In conclusion, fixing the same total Ca/total P ratio in diets supplemented with increasing phytase dosing created an imbalance of digestible Ca and P, which could have an adverse effect on bone mineralization and thus compromise the phytase efficacy relative to mineral P.

Application of Creep Feed and Phytase Super-Dosing as Tools to Support Digestive Adaption and Feed Efficiency in Piglets at Weaning

A total of 64 piglets were used in a 35-day study to evaluate whether creep feeding piglets on the sow or super-dosing phytase to piglets post-weaning can be used as a tool to reduce stress and support adaption to weaning. Treatments consisted of creep or no creep feed being offered pre-weaning and with or without phytase supplementation at 2000 FTU/kg post-weaning. Blood samples were collected from eight piglets per treatment on days 0 (weaning), 7 and 21 post-weaning to determine plasma cortisol and myo-inositol concentrations. Four piglets per treatment (n = 16) were administered Heidelberg pH capsules 1 week prior to weaning, on the day of weaning, as well as 7 days and 21 days post-weaning, with readings monitored over a 3 h period. In the first week post-weaning, creep-fed piglets had higher daily gains (0.23 vs. 0.14 kg/d, p < 0.05) and a lower feed conversion ratio (FCR, 0.99 vs. 1.35, p < 0.01), compared to non-creep-fed pigs. At 21 days post-weaning, irrespective of creep feed, phytase supplementation reduced FCR (1.10 vs. 1.18, p = 0.05) of piglets. Average real-time stomach pH was lower in creep-fed piglets at 1 week prior to weaning (pH 3.2 vs. 4.6, p < 0.001) and on day of weaning (pH 3.1 vs. 3.7, p < 0.01). Following weaning, phytase reduced average stomach pH of piglets at days 7 (pH 2.6 vs. 3.3, p < 0.001) and 21 (pH 2.2 vs. 2.6, p < 0.01). Both cortisol and myo-inositol concentrations in plasma decreased with age; however, cortisol levels were unaffected by either treatment. Plasma myo-inositol concentrations were higher in creep-fed piglets at day of weaning (p < 0.05) and with phytase super-dosing on day 21 (p < 0.001). These findings demonstrate that both creep feeding and phytase super-dosing are useful practices to encourage better adaption to weaning and support piglet performance. This response was not related to reduced stress in piglets, as determined by cortisol levels, but instead appears to relate to improved gastric conditions for digestion, phytate degradation and myo-inositol provision in piglets.

Effect of phytase on nutrient digestibility and expression of intestinal tight junction and nutrient transporter genes in pigs

The study was conducted to determine the effects of high levels of phytase on growth performance, nutrient digestibility, phytate breakdown, and expression of mucosal tight junction and nutrient transporter genes in weanling pigs. A total of 128 barrows were penned in groups of four and used in a randomized completely block design and assigned to four treatments for a 28-d study. A two-phase feeding was implemented (phase 1: day 1 to 14; phase 2: day 15 to 28). The diets differed in dietary calcium (Ca) and phosphorus (P) levels (positive control [PC]: 8.1 to 7.1 g/kg Ca and 6.5 to 6.8 g/kg P; negative control [NC]: 6.6 to 5.5 g/kg Ca and 5.6 to 5.3 g/kg P) from phase 1 to phase 2, respectively. NC diets were supplemented with phytase at 0 (NC), 1,500 (NC + 1,500), or 3,000 (NC + 3,000) phytase units (FTU)/kg. Blood was collected after fasting (day 27) or feeding (day 28) for the measurement of plasma inositol concentrations. On day 28, two pigs per pen were euthanized. Duodenal-jejunal and ileal digesta samples and feces were collected to determine inositol phosphates (InsP3-6) concentrations. Phytase supplementation increased the body weight on days 14 and 28 (P < 0.05). Average daily gain and feed efficiency compared with NC were increased by phytase with the majority of its effect in phase 1 (P < 0.05). The apparent ileal digestibility and apparent total tract digestibility of P were increased in piglets fed phytase-supplemented diets (P < 0.01) compared with NC piglets. Disappearance of InsP6 and total InsP3-6 up to the duodenum-jejunum, ileum, and in feces was increased by both phytase application rates (P < 0.01). Plasma concentrations of myo-inositol were higher (P < 0.001) in the phytase-supplemented diets than PC and NC diets, irrespective of whether pigs were fed or fasted. Expression of claudin 3 was higher in pigs fed both phytase-supplemented diets in the duodenum and jejunum compared with PC and NC. Mucin 2 expression was lower in the ileum of NC + 3,000 fed piglets compared with PC (P < 0.05), whereas expression of GLUT2 (solute carrier family 2-facilitated glucose transporter member 2) was increased (P < 0.05) by the NC + 3,000 treatment in all sections. In summary, high phytase supplementation increased the growth performance of nursery pigs. The increased expression of GLUT2 by phytase may indicate an upregulation of glucose absorption from the intestine by phytase.

Influence of Phytase Supplementation at Increasing Doses from 0 to 1500 FTU/kg on Growth Performance, Nutrient Digestibility, and Bone Status in Grower-Finisher Pigs Fed Phosphorus-Deficient Diets

Simple Summary

The current study investigates the growth performance and bone status of grower–finisher pigs supplemented with phytase, an enzyme which increases the bioavailability of phosphorus in animal feeds. The study results provide new information with regards to the positive role phytase supplementation to livestock feed plays in the achievement of the maximum effectiveness of the feed, as well as numerous positive effects on bone characteristics (geometry, mineralization, and mechanical strength) in grower–finisher pigs.

Abstract

The objective of the current study is to assess the effects of the inclusion of 6-n phytase to a phosphorous-deficient diet on the growth performance (feed intake, average daily gain, and feed conversion ratio), apparent digestibility of calcium and phosphorus, and bone characteristics of grower–finisher pigs. The experimental diets included a phosphorus-deficient diet containing 0 (negative control), 250, 500, 1000, or 1500 FTU/kg of 6-phytase, and a diet formulated to meet the phosphorus nutrient requirements of pigs (positive control). Pigs were fed the experimental diets from the time they were ~35 kg body weight until they reached slaughter weight of ~110 kg. Bone status of the metacarpal (ash, mineral content) and femur (mineralization, geometry, and mechanical strength) bones were assessed. There was no effect of dietary treatment on feed intake. Feed conversion ratio was improved following inclusion of phytase at a dose of 500 FTU/kg or higher. Phytase inclusion at a dose of 1000 FTU/kg increased the average daily weight gain of grower–finisher pigs. Phytase inclusion at a dose of 500 FTU/kg was sufficient to increase metacarpal phosphorus content. Femur mid-diaphysis ash percentage was significantly increased even after the inclusion of the lowest dose of phytase. Analysis of structural parameters of femur mechanical strength (Young’s modulus, yield stress, yield strain, ultimate stress, ultimate strain) showed that the inclusion of a phytase dose of 500 FTU/kg in growing/finishing diets was sufficient to significantly improve bone status of grower–finisher pigs at slaughter.

Effect of phytase on intestinal phytate breakdown, plasma inositol concentrations, and glucose transporter type 4 abundance in muscle membranes of weanling pigs1

The objective of this present study was to determine the effects of phytase dosing on growth performance, mineral digestibility, phytate breakdown, and the level of glucose transporter type 4 (GLUT4) in muscle plasma membranes of weanling pigs. A total of 160 barrows were used in a randomized completely block design and assigned to 4 treatments for a 7-wk study. Depending on the feeding phase, diets differed in dietary calcium (Ca) and phosphorus (P) levels (positive control [PC]: 8 to 6.8g/kg Ca; 7.3 to 6.3 g/kg P; negative control [NC]: 5.5 to 5.2 g/kg Ca; 5.4 to 4.7 g/kg P). NC diets were supplemented with phytase at 0 (NC); 500 (NC + 500 FTU); or 2,000 FTU/kg (NC + 2,000 FTU) phytase units/kg. Blood was collected after fasting (day 48) or feeding (day 49) for measurement of plasma inositol concentrations. On day 49, 2 pigs per pen were euthanized, and duodenal and ileal digesta samples were collected to determine inositol phosphates (InsP6-2) concentrations. High phytase supplementation increased BW on days 21, 35, and 49 (P < 0.05). Over the entire feeding period, ADG, ADFI, and feed efficiency were increased by NC + 2,000 FTU compared with the other treatments (P < 0.05). Postprandial plasma inositol concentration was increased in NC + 2,000 (P < 0.01), but there was only a tendency (P = 0.06) of a higher fasting plasma inositol concentration in this group. Inositol concentrations in the portal vein plasma (day 49) were not different among treatments. Duodenal digesta InsP5 and InsP6 concentrations were similar in PC and NC, but higher in these 2 treatments (P < 0.05) than those supplemented with phytase. Phytase supplementation decreased InsP6-4, resulting in increased InsP3-2 and myo-inositol concentrations. Similar effects were found in ileal contents. Compared with NC, phytase supplementation resulted in greater cumulative InsP6-2 disappearance (93.6% vs. 72.8% vs. 25.0%, for NC + 2,000 FTU, NC + 500 FTU and NC, respectively, P < 0.01) till the distal ileum. Longissimus dorsi muscle plasma membrane GLUT4 concentration was increased by NC + 2,000 FTU (P < 0.01) compared with NC. In summary, high phytase supplementation increased growth performance of nursery pigs. The higher myo-inositol release from phytate could contribute to the increased expression of GLUT4 in muscle plasma membranes. Further investigation is needed to determine whether this is associated with enhanced cellular glucose uptake and utilization.

Effect of phytase on phosphorous balance in 20-kg barrows fed low or adequate phosphorous diets

The effects of phytase on phosphorus (P) digestibility are well established. However, there are few studies that report P balance, particularly when phytase is used in diets that have adequate or deficient P. The main objective of the study was to determine the effect of dietary P levels and exogenous phytase on P balance in growing pigs. The first part of the experiment was a 14-d metabolism study conducted with 80 barrows (initial body weight 18.5 ± 0.5 kg) with a 2 × 5 factorial arrangement of treatments and main effects of available P (0.13% available P, low P [Low-P] diet; 0.35% available P, adequate P [Adeq-P] diet) and phytase (0, 250, 500, 2,500, and 12,500 U/kg). A portion of the pigs (n = 24) fed the Low-P diet, with 0, 500, 2,500, 12,500 U/kg phytase, and those fed the Adeq-P diet, with 0 and 12,500 U/kg phytase, remained on test diets for another 4 d, and tissues were collected for determination of bone characteristics and tissue P concentration. There was a P × phytase interaction for P retention that was accounted for by a lack of response to phytase in pigs fed the Adeq-P diet. Retention of P was greater with incremental levels of phytase in pigs fed Low-P diets as compared to those fed Adeq-P diets (P level × phytase, P < 0.01), but calcium (Ca) retention was greater in pigs fed Adeq-P diets (P level × phytase P < 0.01). Apparent total tract digestibility (ATTD) of P was improved by phytase (P < 0.001) and was greater in pigs fed Adeq-P diets as compared to those fed Low-P diets (P = 0.006). Metatarsal bone ash (quadratic, P = 0.01) and strength (linear, P = 0.03) was increased by phytase addition to the Low-P diets. There were no phytase or dietary P effects on P concentrations of the heart, kidney, liver, muscle, and spleen. These results suggest that as compared to the effects in an Adeq-P diet, adding phytase to a Low-P diet was more effective at reducing the P and Ca excretion and restoring average daily gain (ADG). The P released by phytase is absorbed and contributes to improved bone growth, greater rates of tissue accretion, and increased body weight, but does not change tissue P concentrations. There is, however, a threshold for P retention, beyond which it is excreted in the urine.

The uses of microbial phytase as a feed additive in poultry nutrition – a review

Most of the phosphorus (P) in feed ingredients is present as phytate, which is poorly available for absorption in the gastrointestinal tract of different poultry species due to the lack of endogenous phytase. The supplementation of phytase increases the utilization of P by hydrolyzing phytate, which consequently may reduce the excretion of P in the environment. In addition, it has been suggested that phytase may improve the feed utilization, weight gain, egg production and egg traits, nutrient digestibility, energy availability, retention of important minerals in blood and bones. Thus, the effectiveness of phytase on performance and Ca and P absorption in layer chickens fed corn-soybean based diets has been well recognized. The current review briefly discusses the supplementation of phytase in the diet of poultry on performance and egg production and characteristics as well as amino acids and minerals availability.

Determining the available phosphorus release of Natuphos E 5,000 G phytase for nursery pigs

A total of 288 pigs (PIC 327 × 1050; initially 11.1 ± 0.1 kg, and day 40 of age) were used in a 21-d growth trial to determine the available P (aP) release curve for a novel source of 6-phytase (Natuphos E 5,000 G; BASF Corporation, Florham Park, NJ). Natuphos E is a bacterial derived 6-phytase of which the phytase gene is assembled from a hybrid of phytase-producing bacteria and produced through the fermentation of Aspergillus niger. Pigs were randomly allotted to pens at weaning. From day 15 to 18 postweaning, a common corn-soybean meal diet containing 0.12% aP was fed to all pigs to acclimate them to a P-deficient diet. On day 0 of the experiment (day 19 after weaning), pens were allotted in a randomized complete block design to one of eight treatments. There were four pigs per pen and nine pens per dietary treatment. Pigs were fed a corn-soybean meal-based diet formulated to 1.25% standardized ileal digestible Lys. Experimental diets were formulated to contain 0.73% Ca and increasing aP supplied by either monocalcium P (0.12%, 0.18%, and 0.24% aP) or from increasing phytase (150, 250, 500, 750, and 1,000 phytase unit [FTU]/kg) added to the 0.12% aP diet. Analyzed phytase concentrations were 263, 397, 618, 1,100, and 1,350 FTU/kg, respectively. On day 21 of the study, one pig per pen was euthanized and the right fibula was collected for bone ash and percentage bone ash calculations. From day 0 to 21, increasing P from monocalcium P or phytase improved (linear, P < 0.01) ADG and G:F. Bone ash weight and percentage bone ash increased (linear, P < 0.01) with increasing monocalcium P or phytase. When formulated phytase values and percentage bone ash are used as the response variables, aP release for up to 1,000 FTU/kg of Natuphos E 5,000 G phytase can be predicted by the equation: aP release = 0.000212 × FTU/kg phytase.

Effect of high doses of Natuphos E 5,000 G phytase on growth performance of nursery pigs

A total of 360 pigs (DNA 200 × 400, initially 5.9 ± 0.1 kg) were used in a 42 d trial to determine the effect of high doses of a recently available phytase source (Natuphos E 5000 G, BASF Corporation, Florham Park, NJ) on nursery pig growth and bone ash. Pigs were randomly allotted to pens at weaning by BW and pens were allotted to one of eight corn-soybean meal-based dietary treatments in a randomized complete block design. There were five pigs per pen and nine pens per treatment. Diets were fed in three phases (d 0 to 7, 7 to 21, and 21 to 42) with formulated total calcium:phosphorus (Ca:P) of 1.07, 1.05, and 0.93, respectively. Treatments included a negative control (NC) with 0.40, 0.30, or 0.25% aP from monocalcium P for Phases 1, 2, and 3 respectively; and NC with either 500, 1,000, 2,000, 3,000, or 4,000 FTU/kg phytase. The last two treatments were a positive control (PC) with 0.55, 0.45, or 0.40% aP from monocalcium P for Phases 1, 2, and 3, respectively, or PC with 2,000 FTU/kg phytase. The NC diet with 500 FTU/kg and PC without added phytase were formulated to be equivalent in available Ca and P. On d 42, one pig per pen was euthanized and the right fibula was removed for bone ash analysis. From d 0 to 42, pigs fed increasing phytase in the NC tended to have increased (quadratic, P = 0.064) ADG and (linear, P = 0.082) ending BW and had improved (quadratic, P = 0.008) G:F. Adding 2,000 FTU/kg phytase to the PC did not influence ADG or ADFI, but tended to improve (P = 0.060) G:F compared with the PC. In addition, percentage bone ash increased as phytase increased in the NC (linear, P < 0.001) or when 2,000 FTU/kg was added to the PC diets (P < 0.001). Pigs fed the PC had increased (P = 0.007) ADFI and tended to have greater (P = 0.099) percentage bone ash than pigs fed NC+500 FTU/kg phytase, but the pigs fed NC+500 FTU/kg phytase had improved (P = 0.032) G:F compared to pigs fed the PC. In summary, increasing concentrations of dietary phytase in a P-deficient diet improved growth and bone ash measurements, and was optimized at 1,000 FTU/kg. There were varied improvements when 2,000 FTU/kg phytase was added in P adequate diets.

High dose of phytase on apparent and standardized total tract digestibility of phosphorus and apparent total tract digestibility of calcium in canola meals from Brassica napus black and Brassica juncea yellow fed to growing pigs

A total of 42 barrows weighing 19.8 ± 1.22 kg were fed seven diets to give six replicates per treatment. The experiment was conducted in a factorial arrangement with factors being (1) two canola meals (CM) types and (2) three phytase levels (0, 500, and 2500 FTU kg−1). The basal endogenous phosphorus (P) losses and standardized total tract digestibility (STTD) was calculated using the P-free method. There was no effect of CM types on feed intake and fecal P output, but an interaction effect was observed for P intake (CM × phytase; P < 0.05). Supplementation of phytase (2500 FTU kg−1) reduced (P < 0.001) fecal P output (g d−1), and the output was reduced by 58% in Brassica napus black (BNB) and 64% in Brassica juncea yellow (BJY) diets. Supplementation of phytase improved (P < 0.001) both apparent total tract digestibility (ATTD) and STTD of P in both BNB and BJY, regardless of dose. The basal endogenous P loss (EPL) was determined to be 111.28 ± 35.09 mg kg−1 of dry matter intake (DMI). There was no further improvement in STTD of P when phytase was increased from 500 to 2500 FTU kg−1 in both CM types. The ATTD of calcium (Ca) was increased (P < 0.001) in BNB and BJY when phytase was supplemented at 500 and 2500 FTU kg−1. The results, therefore, indicate that supplementation of phytase at 500 FTU kg−1 improved both ATTD and STTD of P in two CM types, but a super dose of 2500 FTU kg−1 had no additional benefit. Similarly, ATTD of Ca was increased when phytase was supplemented at 500 FTU kg−1 without further improvement at 2500 FTU kg−1.

Effects of a novel bacterial phytase expressed in Aspergillus Oryzae on digestibility of calcium and phosphorus in diets fed to weanling or growing pigs

In 2 experiments, 48 weanling (initial BW: 13.5 ± 2.4 kg, Exp. 1) and 24 growing pigs (initial BW: 36.2 ± 4.0 kg, Exp. 2) were used to determine effects of a novel bacterial 6-phytase expressed in Aspergillus oryzae on the apparent total tract digestibility (ATTD) of phosphorus and calcium in corn-soybean meal diets fed to weanling and growing pigs. In Exp. 1 and 2, pigs were randomly allotted to 6 dietary treatments using a randomized complete block design and a balanced 2 period changeover design, respectively. In both experiments, 6 diets were formulated. The positive control diet was a corn-soybean meal diet with added inorganic phosphorus (Exp. 1: 0.42 and 0.86% standardized total tract digestible phosphorus and total calcium, respectively; Exp. 2: 0.32 and 0.79% standardized total tract digestible phosphorus and total calcium, respectively). A negative control diet and 4 diets with the novel phytase (Ronozyme HiPhos, DSM Nutritional Products Inc., Parsippany, NJ) added to the negative control diet at levels of 500, 1,000, 2,000, and 4,000 phytase units (FYT)/kg were also formulated. In Exp. 1, the ATTD of phosphorus was greater (P < 0.01) for the positive control diet (60.5%) than for the negative control diet (40.5%), but increased (linear and quadratic, P < 0.01) as phytase was added to the negative control diet (40.5% vs. 61.6%, 65.1%, 68.7%, and 68.0%). The breakpoint for the ATTD of phosphorus (68.4%) was reached at a phytase inclusion level of 1,016 FYT/kg. In Exp. 2, the ATTD of phosphorus was greater (P < 0.01) for the positive control diet (59.4%) than for the negative control diet (39.8%) and increased (linear and quadratic, P < 0.01) as phytase was added to the negative control diet (39.8% vs. 58.1%, 65.4%, 69.1%, and 72.8%). The breakpoint for the ATTD of phosphorus (69.1%) was reached at a phytase inclusion level of 801 FYT/kg. In conclusion, the novel bacterial 6-phytase improved the ATTD of phosphorus and calcium in both weanling and growing pigs. The optimum level of inclusion for this phytase is 800 to 1,000 FYT/kg of complete feed to maximize ATTD of phosphorus and calcium in weanling and growing pigs.

Meta-analysis of phosphorus utilization by growing pigs: effect of dietary phosphorus, calcium and exogenous phytase

Optimizing phosphorus (P) utilization in pigs requires improving our capacity to predict the amount of P absorbed and retained, with the main modulating factors taken into account, as well as precisely determining the P requirements of the animals. Given the large amount of published data on P utilization in pigs, a meta-analysis was performed to quantify the impact of the different dietary P forms, calcium (Ca) and exogenous phytases on the digestive and metabolic utilization criteria for dietary P in growing pigs. Accordingly, the amount of phytate P (PP) leading to digestible P (g/kg) was estimated to be 21%, compared with 73% for non-phytate P (NPP) from plant ingredients and 80% for NPP from mineral and animal ingredients (P < 0.001). The increase in total digestible dietary P following the addition of microbial phytase (PhytM) from Aspergillus niger (P < 0.001) was curvilinear and about two times higher than the increase following the addition of plant phytase, which leads to a linear response (P < 0.001). The response of digestible P to PhytM also depends on the amount of substrate, PP (PhytM(2) × PP, P < 0.001). The digestibility of dietary P decreased with dietary Ca concentration (P < 0.01) independently of phytase but increased with body weight (BW, P < 0.05). Although total digestible dietary P increased linearly with total NPP concentration (P < 0.001), retained P (g/kg), average daily gain (ADG, g/day) and average daily feed intake (ADFI, g/day) increased curvilinearly (P < 0.001). Interestingly, whereas dietary Ca negatively affected P digestibility, the effect of dietary Ca on retained P, ADG and ADFI depended on total dietary NPP (NPP × Ca, P < 0.01, P < 0.05 and P < 0.01, respectively). Increasing dietary Ca reduced retained P, ADG and ADFI at low NPP levels, but at higher NPP concentrations it had no effect on ADG and ADFI despite a positive effect on retained P. Although the curvilinear effect of PhytM on digestible P increased with PP (P < 0.001), this effect was lessened by total NPP for ADG and ADFI (PhytM × NPP and PhytM(2) × NPP, P < 0.05) and depended on both total NPP and Ca for retained P (PhytM(2) × NPP × Ca, P < 0.01). This meta-analysis improves our understanding of P utilization, with major modulating factors taken into account. The information generated will be useful for the development of robust models to formulate environmentally friendly diets for growing pigs.

Growth performance, diet nutrient digestibility, and bone mineralization in weaned pigs fed pelleted diets containing thermostable phytase

Traditional supplemental dietary phytase loses activity during steam pelleting. The thermal tolerance and bioefficacy of a phytase product with a thermoprotective coating [coated phytase (C-phytase)] was compared in mash and pelleted diets to a traditional, uncoated phytase (U-phytase) added to a negative control (NC) diet, formulated with reduced dietary Ca and P, and compared with a corn-soybean meal based positive control (POC) diet. Growth performance, nutrient digestibility, and third metacarpal bone characteristics were response variables. Weaned pigs (n = 56; 8.20 ± 0.5 kg initial BW; 28 d of age) were individually housed and randomly allotted to 1 of 7 diets for 21 d. The diets were 1) POC mash, 2) NC mash, 3) NC pelleted at 90°C, 4) NC mash + 500 U/kg U-phytase, 5) NC mash + 500 U/kg C-phytase, 6) NC + 500 U/kg C-phytase pelleted at 80°C, and 7) NC + 500 U/kg C-phytase pelleted at 90°C. The POC and NC diets were formulated to be isoenergetic and isolysinic. The content of Ca and available P was 1.01 and 0.40% and 0.83 and 0.22% in the POC and NC diets, respectively. Pig BW and feed intake were measured on d 7, 14, and 21, and feces were collected for 2 d. On d 21, pigs were killed and ileal digesta and the third metacarpal bone collected. Pigs fed POC had greater (P < 0.05) ADG, G:F, P digestibility, and bone mineralization but lower (P < 0.01) energy digestibility than pigs fed NC. Pelleting the NC diet did not improve performance, nutrient digestibility, or P use. Adding the U-phytase to NC mash diet increased (P < 0.05) ADG, G:F, apparent ileal digestibility (AID) of CP and Ile, Leu, Phe, Thr, Val, and Ser, and apparent total tract digestibility (ATTD) of P compared with pigs fed NC. Pigs fed C-phytase in NC mash diets had increased (P < 0.05) G:F and an AID of CP and AA and ATTD of P compared with pigs fed NC but not different than pigs fed U-phytase NC mash diets. Pigs fed pelleted NC diet with C-phytase had a greater (P < 0.05) ATTD of P and energy than pigs fed mash NC diet with C-phytase but had similar growth performance, AID of CP and AA, and bone mineralization to pigs fed U-phytase. In conclusion, release and bioefficacy of phytase after pelleting was not affected by the thermal protective coating.

Replacement of zinc sulphate by microbial phytase for piglets given a maize-soya-bean meal diet

Forty-eight pigs, weaned at 27 days of age at an average body weight of 7·55 kg were used in a 19-day experiment to investigate the influence of microbial phytase on zinc utilization and to calculate equivalency values of zinc as sulphate for microbial phytase. Eight experimental diets were formulated: a maize-soya-bean meal basal diet containing 30 mg of zinc per kg supplemented with 10, 25, 40 or 100 mg of zinc from sulphate (ZnSO4, 7H2O) per kg or with 100, 250, 500 or 750 units (U) of microbial phytase (3- phytase from Aspergillus niger, Natuphos ®) per kg. The dietary supplies of calcium and phosphorus were adjusted accounting for the release of these elements by microbial phytase. The copper concentration in the diets was 11 mg/kg. Pigs were given the basal diet for a 7-day adjustment period prior to the 19-day experimental period. At the end of the experiment, bone ash, phosphorus and calcium concentrations as well as plasma and liver copper concentrations were independent of the diet (P> 0·10). The zinc status of piglets was assessed through plasma alkaline phosphatase activity (APA) and zinc concentration, bone zinc concentration and liver zinc concentration. Plasma zinc, plasma APA and bone zinc increased linearly (P< 0·001) and quadratically (P< 0·01,P< 0·001 andP< 0·001, respectively) with zinc added. These parameters also increased linearly (P< 0·001) and quadratically (P< 0·05,P< 0·001 andP< 0·05, respectively) with phytase added. Liver zinc increased quadratically (P< 0·05) with zinc added and tended to increase linearly with phytase added (P= 0·077). Linear and non-linear response equations of indicators of zinc status to zinc added and phytase added were developed and used to calculate zinc equivalency values of phytase. Non-linear models were linear plateau models for zinc added and exponential models for phytase added. Plasma APA, plasma zinc and bone zinc were maximized when zinc added reached 43, 54 and 56 mg/kg of diet, respectively. The mean function of equivalency of zinc as sulphate (Zn, mg/kg of diet) for microbial phytase (Phyt, U per kg of diet) was Zn = 49·9 − 58·3 e−0·00233Phyt. From this equation it is calculated that 250, 500, and 750 U of 3-phytase from Aspergillus niger can avoid the addition of 17, 32 and 40 mg of zinc as sulphate in a piglet diet. Zinc ingested and, in turn, zinc excreted, may be proportionately reduced by almost 0·30 by replacing 30 mg of zinc as sulphate by 500 U of phytase as Natuphos ® in a piglet maize and soya-bean meal diet formulated to contain 100 mg of zinc per kg.

Effect of graded doses and a high dose of microbial phytase on the digestibility of various minerals in weaner pigs

An experiment with 224 weaner pigs (initial BW of 7.8 kg) was conducted to determine the effect of dose of dietary phytase supplementation on apparent fecal digestibility of minerals (P, Ca, Mg, Na, K, and Cu) and on performance. Four blocks, each with 8 pens of 7 pigs, were formed. Eight dietary treatments were applied to each block in the 43-d experiment: supplementation of 0 (basal diet), 100, 250, 500, 750, 1,500, or 15,000 phytase units (FTU) or of 1.5 g of digestible P (dP; monocalcium phosphate; positive control) per kilogram of feed. The basal diet, with corn, barley, soybean meal, and sunflower seed meal as the main components, contained 1.2 g of dP per kilogram of feed. Fresh fecal grab samples were collected in wk 4 and 5 of the experiment. Average daily feed intake, ADG, G:F, and digestibility of all of the minerals increased (P < 0.001) with increasing phytase dose. Digestibility of P increased from 34% in the basal diet to a maximum of 84% in the diet supplemented with 15,000 FTU, generating 1.76 g of dP per kilogram of feed. At this level, 85% of the phytate phosphorus was digested, compared with 15% in the basal diet. Compared with the basal diet, digestibility of the monovalent minerals increased maximally at 15,000 FTU, from 81 to 92% (Na) and from 76 to 86% (K). In conclusion, phytase supplementation up to a level of 15,000 FTU/kg of a dP-deficient diet improved performance of weaner pigs and digestibility of minerals, including monovalent minerals. Up to 85% of the phytate-P was digested. Thus, dietary phytase supplementation beyond present day standards (500 FTU/kg) could further improve mineral use and consequently reduce mineral output to the environment.

Estimating equivalency values of microbial phytase for amino acids in growing and finishing pigs fitted with steered ileo-cecal valve cannulas

Ten crossbred barrows (48.3 +/- 2.3 kg of initial BW) fitted with steered ileo-cecal valve cannulas were used to investigate the effects of supplemental microbial phytase on the apparent ileal digestibilities (AID) of AA, Ca, P, N, and DM, and the apparent total tract digestibilities of Ca, P, N, and DM. All diets were corn-soybean meal-based, and contained 0.44% Ca and 0.40% total P. Diets 1, 2, and 3 contained 12.0, 11.1, and 10.2% CP, respectively. Diets 4 and 5 had the same ingredient composition as diet 3, plus 250 and 500 U/kg phytase (Natuphos), respectively. Pigs were randomly allotted to 1 of 5 dietary treatments in a paired 5 x 5 Latin square with an extra period to test for carryover effects. Each 14-d period consisted of a 7-d adjustment followed by a 3-d total collection, a 12-h ileal digesta collection, a 3-d readjustment, and a second 12-h ileal digesta collection. Pigs were housed individually in metabolism pens (1.2 x 1.2 m). Water was supplied ad libitum, and feed was supplied at a level of 9% of the metabolic BW (BW(0.75)) per day in 2 equal daily feedings. As the dietary CP concentration increased, the AID of CP and all AA measured increased linearly (P < 0.05) with the exception of proline. In addition, the apparent total tract digestibilities (grams per day) and retention of N (grams per day) increased linearly (P < 0.01) with increasing CP levels. Supplementing diets with phytase increased the AID of Ca (P < 0.01), P (P < 0.001), CP (P = 0.07), and the AA (P < 0.10) Gly, Ala, Val, Ile, Thr, TSAA, Asp, Glu, Phe, Lys, and Arg. Protein and phytase response equations were generated for those AA affected (P < 0.10) by both CP level and phytase supplementation. Based on these equations, 500 U/kg of phytase can replace 0.52 percentage units of the dietary CP, which includes a 0.03 percentage unit improvement in Lys AID. The results of this study show that supplementing pig diets with microbial phytase improves CP and AA digestibilities in addition to Ca and P digestibilities.

Total and water-soluble phosphorus excretion from swine fed low-phytate soybeans

A study was conducted to evaluate the impact of feeding soybean meal (SBM) from low-phytate (LP) or traditional phytate (TP) soybeans on performance and excretions from growing swine. Ninety-six crossbred barrows (initial BW = 18 +/- 0.3 kg) were allocated by BW to 24 pens and fed 1 of 4 treatment diets: TP SBM without supplemental phytase; TP SBM plus 500 phytase units of phytase/kg, as-fed basis [Ronozyme P (CT) 2500; DSM Nutritional Products, Basel, Switzerland]; LP SBM (USDA-ARS breeding line CX1834-1) without supplemental phytase, and LP SBM plus phytase. All diets within a feeding phase were formulated to be isocaloric and have similar available Lys and nonphytin P content. Pens were assigned randomly to treatments at the beginning of each of the 4 feeding phases. An indigestible marker was added to the mash feed. Individual pig weights and fecal samples were collected, and feed disappearance by pen was recorded weekly. No phytase inclusion or SBM source effects were observed for pen ADG, ADFI, or G:F (P > 0.05). Total tract apparent digestibility of DM and OM was not different among treatment groups (P > 0.05). Apparent digestibility of P was greater for pigs fed diets containing the LP SBM (48.9 vs. 42.4%; P < 0.01) and less when diets included phytase (44.3 vs. 47.0%; P < 0.0001). Total P (tP) and water-soluble P (WSP) excreted were affected by dietary treatment (tP: 20.0, 18.0, 16.8, and 13.8 g/kg of feces DM, P < 0.01; and WSP: 10.9, 10.1, 9.1, and 8.5 g/kg, P < 0.01, for TP SBM without supplemental phytase, TP SBM plus 500 phytase units of phytase/kg, LP SBM without supplemental phytase, and LP SBM plus phytase diets, respectively). Inclusion of phytase decreased tP and WSP excreted (P < 0.01), as did use of LP SBM (P < 0.01). Diet effects on the fraction of excreted tP that was WSP were observed (P < 0.01); however, there was not a significant effect of SBM source. Inclusion of exogenous phytase in diets increased the proportion of tP that was excreted as WSP from 55% in diets without phytase to 59% in diets containing phytase. The findings suggest that there is a need for LP soybeans as a dietary component to minimize environmental impacts.

Effect of microbial phytase on apparent ileal amino acid digestibility of phosphorus-adequate diets in growing pigs

Six ileally cannulated pigs (mean initial body weight 34.8 kg) were used to study the effect of microbial phytase on apparent ileal digestibility of P, total N and amino acids. Three P-adequate diets (digestible P concentration 2.3 g kg(- )l) containing barley (B), soyabean meal (S) or a mixture of the two (BS) with or without phytase supplement (1000 FTU x kg(-1)) were fed to pigs using a 6 x 6 Latin square design. The addition of phytase increased (p < 0.05) apparent ileal P digestibility of diets B, S and BS by 16.5, 19.2 and 19.2%, respectively. There was no effect of phytase on the ileal digestibility of total N. Apparent ileal digestibility of amino acids tended to increase in the BS diet supplemented with phytase (mean improvement of 2.2%); but no significant difference was found for any amino acid as compared with the unsupplemented diet. To asses the additivity of apparent amino acid digestibility, the determined values for the BS diet were compared to those calculated from digestibilities found in diets B and S. There were no significant differences between the determined and calculated values. It is concluded that the addition of microbial phytase to P-adequate diets does not affect ileal amino acid digestibility in growing pigs and that the apparent amino acid digestibility values determined in single ingredients may be additive when included into a complex diet.

Assessment of dietary zinc requirement of weaned piglets fed diets with or without microbial phytase

Fifty-four pigs, weaned at 26 days of age at an average body weight of 7.74 kg were used in a 26-day experiment to assess the zinc requirement of piglets, using diets based on maize and soybean meal, with or without microbial phytase. The nine experimental diets were the basal diet containing 33 mg of zinc/kg supplemented with 10, 25, 40, 60 or 80 mg of zinc as sulphate (ZnSO(4), 7H(2)O)/kg and the basal diet supplemented with 0, 10, 25 or 40 mg of zinc as sulphate/kg and 700 units (U) of microbial phytase (Natuphos)/kg. Pigs were fed the basal diet for a 7-day adjustment period prior to the 19-day experimental period. Microbial phytase enhanced plasma alkaline phosphatase (AP) activity, plasma zinc and bone zinc concentrations. These parameters increased linearly with zinc intake, with a similar slope with and without phytase. The response of bone zinc-to-zinc added did not plateau. Without microbial phytase, plasma AP activity and zinc concentration were maximized when dietary zinc reached 86 and 92 mg/kg respectively. With microbial phytase they were maximized when dietary zinc concentration reached 54 and 49 mg/kg respectively. Accounting for a safety margin, the recommended supply of zinc for weaned piglets up to 16 kg fed maize-soybean meal diets supplemented with zinc as sulphate is thus of 100-110 mg/kg diet. This supply may be reduced by around 35 mg if the diet is supplemented with 700 U of microbial phytase.

Effects of microbial phytase, low calcium and phosphorus, and removing the dietary trace mineral premix on carcass traits, pork quality, plasma metabolites, and tissue mineral content in growing-finishing pigs

An experiment was conducted to determine the effects of phytase addition, reduced Ca and available P (aP), and removing the trace mineral premix (TMP) on growth performance, plasma metabolites, carcass traits, pork quality, and tissue mineral content in growing-finishing swine. One hundred twenty cross-bred pigs (initial and final BW of 22 and 109 kg, respectively) were allotted to five dietary treatments on the basis of weight within gender in a randomized complete block design. There were three replications of barrows and three replications of gilts, with four pigs per replicate pen. The dietary treatments were as follows: 1) corn-soybean meal (C-SBM), 2) C-SBM with reduced Ca and aP, 3) C-SBM with reduced Ca and aP plus 500 phytase units/kg of diet, 4) Diet 1 without the TMP, and 5) Diet 3 without the TMP. The Ca and aP were reduced by 0.10% in the low Ca and aP diets and the diets with added phytase. Daily gain, hot carcass weight, dressing percent, kilograms of carcass lean, bone ash percent, and bone strength were decreased (P = 0.10), but liver and kidney weight were increased (P = 0.10) in pigs fed diets with reduced Ca and aP; adding phytase reversed these responses (P = 0.10). The Commission Internationale de I'Eclairage L* was decreased (P = 0.09) in pigs fed the low Ca and aP diet plus phytase relative to those fed the control diet. Removing the TMP had no effect on overall growth performance, but it increased (P = 0.03) 10th-rib backfat thickness and fasting glucose and decreased (P = 0.03) carcass length and ham weight. Liver weight and liver weight as a percentage of final BW were not affected when phytase was added to the control diet, but removing the TMP increased liver weight and liver weight as a percentage of final BW; adding phytase reversed these responses (phytase x TMP, P = 0.06). Removing the TMP decreased (P = 0.08) Zn concentrations in the bone, muscle, and liver, and Cu and Fe concentrations in the bile but increased (P = 0.08) Mn concentrations in the bile and liver of pigs. The addition of phytase reversed the negative effects of the reduced Ca and aP diets. These data indicate that removing the TMP in diets for growing-finishing pigs has no negative effects on growth performance or pork quality, but it had negative effects on carcass traits and had variable effects on tissue mineral content.

Influence of phytase added to a vegetarian diet on bone metabolism in pregnant and lactating sows

The purpose of the study was to find out if the supplementation of phytase to a diet of gestating and lactating sows has any effects on performance and bone parameters of the animals. Forty primiparous gilts were assigned into four groups: group A with phytase [4.2 g total phosphorus (P)/kg (gestation) and 4.5 g total P/kg (lactation)], group B without phytase (with phytase supplementation in diet for rearing) and same P content as group A, group C without phytase and higher P contents [5.0 g total P/kg (gestation) and 5.5 g total P/kg (lactation)] and group D with the same diet as group B (no phytase during the rearing). A 6-phytase was used in this trial (750 FTU/kg diet). The four diets were fed during gestation and lactation. Faeces were collected to determine apparent digestibility of minerals. Blood samples were taken to analyse minerals and bone markers. After weaning the sows were slaughtered and the bones of one hind leg were prepared to measure bone mineral density (BMD) and bone mineral content (BMC) of the tibia. Bone ash and mineral content of the phalanx III were determined. Mean P concentrations in serum decreased during gestation and lactation. But there were no significant differences between the groups. Bone formation marker bone-specific alkaline phosphatase decreased at the beginning of lactation whereas bone resorption marker serum crosslaps increased. The BMD and BMC of the tibia were slightly higher in the groups fed higher concentrations of P and phytase. The ash and mineral contents of the phalanx were the highest for the group fed the highest concentration of P. The apparent digestibility of P increased during gestation mostly in group A (57%--> 69%). In conclusion, high P content and addition of phytase to the diet induced a slightly higher ash content of the bones. It is of high importance, that sows during gestation absorb enough P, to avoid lamenesses and sudden fractures. As not many studies with phytase have been performed during gestation and lactation in sows yet, we can recommend, that phytase as supplement can be used to keep P in the diet at a lower level without negative consequences for bone health.

Effect of microbial phytase addition with or without the trace mineral premix in nursery, growing, and finishing pig diets1,2

Two experiments were conducted to determine the interactive effects of phytase with and without a trace mineral premix (TMP) in diets for nursery, growing, and finishing pigs on growth performance, bone responses, and tissue mineral concentrations. Pigs (initial and final BW of 5.5 and 111.6 kg [Exp. 1] or 5.4 and 22.6 kg [Exp. 2]) were allotted to treatments on the basis of BW with eight (Exp. 1) or six (Exp. 2) replications of six or seven pigs per replicate pen. Pigs were started on the diets the day of weaning (average of 18 d). In both experiments, the treatments were with or without 500 phytase units/kg of diet and with or without the TMP in a 2 x 2 factorial arrangement. The Ca and available P concentrations were decreased by 0.10% in diets with phytase. The nursery phase consisted of Phase I (7 d), Phase II (14 d), and Phase III (13 d) periods. In Exp. 1, 26 of 52 pigs fed the diet without the TMP and without phytase had severe skin lesions and decreased growth performance; therefore, pigs fed this diet were switched to the positive control diet. In Exp. 2, the treatment without the TMP and without phytase had 12 replications instead of six. At the end of Phase III, half these replications were switched to the positive control diet and half were switched to the diet without the TMP but with phytase. In Exp. 1 during Phases II and III and in the overall data, pigs fed the diet without the TMP had decreased ADG and ADFI, but the addition of phytase prevented these responses (phytase x TMP; P < 0.02). Growth performance was not affected by diet during the growing-finishing period. Coccygeal bone Zn and Na concentrations were decreased (P < 0.09) in pigs fed the diet without the TMP, and adding phytase increased (P < 0.03) Zn and Fe concentrations. In Exp. 2 during Phases I and II, pigs fed the diet without the TMP had decreased ADG, but the addition of phytase prevented this response (phytase x TMP; P < 0.10). Pigs fed the diet without the TMP had decreased (P < 0.10) ADG (Phase II and overall), ADFI (Phases II and III and in the overall data), and G:F (Phase III). Coccygeal bone Zn and Cu concentrations were decreased (P < 0.09) in pigs fed the diet without the TMP, and adding phytase increased (P < 0.03) Zn concentration in the bones. These data indicate that removing the TMP in diets for nursery pigs decreases growth performance and bone mineral content, and that phytase addition to the diet without the TMP prevented the decreased growth performance.

The effect of supplementing microbial phytase and organic acids to a corn-soybean based diet fed to early-weaned pigs

The effect of microbial phytase (MP) and organic acids (OA) supplementation in diets for early-weaned pigs was investigated in an in vitro assay and a growth performance and digestibility trial involving 96 pigs (18 d old). The experimental diets were: 1) a control (C) formulated according to NRC (1998); 2) a negative control (NC) that was similar to diet C except that available P was reduced by 0.19%; 3) NC plus MP (500 U/kg); and 4) NC+MP and OA (NC+MPOA). In the in vitro assay, the four diets were incubated under simulated gut conditions. Addition of MP increased (P = 0.003) phytate hydrolysis from 34 (NC) to 87.5% (NC+MP); this was further increased to 90.1% due to the addition of OA (NC+MPOA). In the 4-wk growth trial, each diet was randomly assigned to six pens each with four pigs. At the end of wk 3, a mobility test was conducted on one pig randomly selected from each pen. Pigs fed the NC diet tended to have a lower (P = 0.06) mobility score compared with those fed the other diets. At the end of wk 4, six pigs per treatment were killed and samples of digesta from different sections of the gut and the third metatarsal bone were collected for nutrient digestibility and bone ash measurements, respectively. There were no differences in ADFI, ADG, and gain:feed ratio among treatments (P > 0.05); however, ADG was 6.5% higher in piglets fed the NC+MPOA diet compared with those fed the C diet. Bone ash content was lower (P = 0.003) in NC fed pigs than in those fed the other treatments. Supplementing NC with MP and MP+OA improved bone ash content to the same level as C. Apparent ileal digestibility (AID) of DM and CP did not differ (P > 0.10) among treatments and averaged 80.7 and 79.4%, respectively. Of all AA, only AID of isoleucine, histidine, and aspartic acid was increased (P < 0.05) by MP+OA supplementation. Overall, there were slight numerical improvements in AID of AA due to MP and OA supplementation, with AID of essential AA averaging 79.4, 77.7, 80.1, and 81.6% for C, NC, NC+MP, and NC+MPOA, respectively. The AID of P was increased (P = 0.0001) by 21 percentage units, and the amount of P excreted was decreased (P = 0.03) by 19.4% as a result of MP+OA supplementation compared with C. In conclusion, addition of MP and OA to pig starter diets improved P digestion and utilization, thereby leading to a reduction in P excretion. Addition of MP and OA to corn-soybean meal diets fed to young pigs had only a slight effect on ileal amino acid digestibilities.