| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
ANIMAL NUTRITION |
* Department of Animal Sciences, Louisiana State University Agricultural Center, Baton Rouge 70803 and
and
Department of Veterinary Clinical Sciences, Louisiana State UniversitySchool of Veterinary Medicine, Baton Rouge 70803
Abstract
Two experiments were conducted to determine the effect of phytase on plasma metabolites and AA and energy digestibility in swine. In Exp. 1, eight barrows (surgery BW = 52 kg) were fitted with steered ileocecal cannulas. The experiment was a Latin rectangle and the treatments were 1) corn-soybean meal diet adequate in Ca and P (0.5% Ca, 0.19% available P [aP]), 2) corn-soybean meal diet with reduced Ca and P (0.4% Ca, 0.09% aP), 3) Diet 1 with 500 phytase units/kg, or 4) Diet 2 with 500 phytase units/kg. Pigs were fed twice daily to a total daily energy intake of 2.6 x maintenance (106 kcal of ME/kg of BW0.75). For each ileal digesta sample, digesta samples were collected for two 24-h periods and combined for each pig. The combination of supplementing with phytase and decreasing the concentration of dietary Ca and P increased average ileal AA (P < 0.02), starch (P < 0.02), GE (P < 0.04), and DM (P < 0.03) digestibilities. In Exp. 2, a feeding challenge was conducted with barrows (eight per treatment; average BW of 53 kg). The treatments consisted of a corn-soybean meal diet or corn-soybean meal diet + 500 phytase units per kilogram of diet. In the diet with no phytase, Ca and aP were at 0.50% and 0.19%, respectively, and, in the diet with phytase, Ca and aP were each decreased by 0.12%. A catheter was surgically inserted into the anterior vena cava of each pig 6 d before the start of the feeding challenge. The barrows were penned individually, and the diets were fed for 3 d before the challenge. The pigs were held without feed for 16 h, and blood samples were obtained at -60, -30, and 0 min before the pigs were fed (2% of BW). Blood samples were then collected at 10, 20, 30, 40, 50, 60, 75, 90, 105, 120, 150, 180, 210, 240, 270, and 300 min after feeding. Glucose area under the response curve and plasma glucose, insulin, urea N, and total 
-amino N concentrations were increased (P < 0.05) in pigs fed the diet with reduced Ca and P and the phytase addition. Area under the response curve for insulin, urea N, and total -amino N; insulin:glucose; and plasma NEFA concentration, clearance, and half-life were not affected by diet. In conclusion, the combination of Ca and P reduction and phytase addition increased nutrient and energy digestibility in diets for pigs and increased plasma concentrations of glucose, insulin, urea N, and -amino N.
Key Words: Amino Acids • Digestibility • Energy • Phytase • Pigs
Introduction
Phytate is an anionic compound with strong antinutritional effects, of which the most documented is that phytate P is largely unavailable to nonruminants (Nelson et al., 1968
). Phytate negatively affects AA availability in feedstuffs (Ravindran et al., 1999), and it has been shown to decrease the activity of digestive enzymes (Deshpande and Cheryan, 1984; Knuckles and Betschart, 1987; Caldwell, 1992), to bind to dietary proteins and AA, and to form Ca-phosphate-phytate complexes with carbohydrate (Thompson and Yoon, 1984). Ravindran and Bryden (1999) also suggested that Ca-phytate complexes with fatty acids in the gut lumen and forms insoluble metallic soaps, thus lowering fat digestibility.
Dietary phytase improves dietary phytate P bioavailability in pigs (Jongbloed et al., 1992; Lei et al., 1993; Cromwell et al., 1995). Phytase also has been shown to improve protein and AA utilization in pigs (Mroz et al., 1994; Biehl and Baker, 1996; Radcliffe et al., 1999). However, other reports showed no change in DM, N, or AA digestibility (Jongbloed et al., 1992; O’Quinn et al., 1997; Traylor et al., 2001) with phytase addition.
Mineral concentrations in diets for nonruminants also have an effect on nutrient availability. Ileal digestibilities of essential AA and N were increased (Yi et al., 1996a) when dietary nonphytate P concentration was decreased from 0.60 to 0.45% in diets for poults. Näsi (1990) reported that total-tract digestibility of CP was greater in pigs receiving diets without an inorganic P supplement. Yi et al. (1996b) reported that the digestibility of DM and apparent absorption of N were decreased as the amount of available P (aP) was increased in diets for pigs.
Thus, the objectives of these experiments were to determine whether the reduction of dietary Ca and P, the addition of phytase, or the combination of these two treatments would increase nutrient digestibility and utilization in corn-soybean meal (C-SBM) diets for pigs.
Materials and Methods
The materials and methods used in these experiments were approved by the Louisiana State University Agricultural Center Animal Care and Use Committee.
Experiment 1
Eight crossbred barrows (Yorkshire x Landrace) with an average BW of 45 kg were individually penned in 0.6- x 1.2-m polyvinyl chloride metabolism crates. During the preliminary period, they were fed a 
SBM basal diet adequate in all nutrients (NRC, 1998) and formulated to provide 1.0% Lys. Feed was mixed with water and fed to appetite twice daily, and water was provided on an ad libitum basis between feedings. At an average BW of 52 kg, steered ileocecal cannulas (Bar Diamond Inc., Parma, ID) were surgically inserted as described by Mroz et al. (1996), with the following modifications: feed was withheld for 36 h and water was withheld for 12 h before surgery. One day before and 3 d after surgery, pigs were given i.m. injections of Excenel (ceftiofur hydrochloride, 1 mL/45.4 kg BW; Pharmacia & Upjohn Animal Health, Kalamazoo, MI) for prevention of infection, and Banamine (flunixin meglumine, 1 mL/45.4 kg BW; Schering-Plough Animal Health, Madison, NJ) for prevention of pain. Before surgery, anesthesia was induced using an i.m. injection of Telazol (1 mL/45.4 kg BW; Fort Dodge Laboratories, Fort Dodge, IA) plus xylazine (Mobay Corp., Shawnee, KS), and anesthesia was maintained during surgery using halothane. Eleven days after the last pig was cannulated, treatments (Table 1) were initiated. Pigs were fed twice daily at 0700 and 1900 to a total daily intake of 2.6 times the maintenance requirement of 106 kcal of ME/kg of BW0.75 (NRC, 1998). As in the preliminary period, feed was mixed with water, and water was provided on an ad libitum basis between feedings. Pigs were weighed weekly and the amount of feed given was adjusted accordingly. At the end of the 56-d experiment, necropsy revealed no visible lesions, and pigs gained 0.63 kg/d during the entire experiment.
|
) were 1) Diet 1: CSBM (0.5% Ca, 0.19% aP), 2) Diet 2: CSBM (0.4% Ca, 0.09% aP), 3) Diet 1 + 500 phytase units/kg, and 4) Diet 2 + 500 phytase units/kg (Natuphos 600; BASF Corp., Mount Olive, NJ). Feed was prepared at 2-wk intervals during the experimental period by mixing a reduced Ca and P basal diet with no phytase and adding limestone and monocalcium phosphate or sand, and rice hulls or phytase in the proper amounts. Sand was added in place of limestone and monocalcium phosphate to maintain corn and soybean meal levels equal in the diets. Analysis of the diets for phytase indicated that Diets 1 and 2 contained no phytase and Diets 3 and 4 contained 544 and 591 phytase units/kg, respectively (Chen, 1996). Chromic oxide was mixed as one part chromic oxide to one part cornstarch, and this mixture was added to the diets at a rate of 0.2% so that the concentration of chromic oxide in the diet was 0.1%, which was used as an indigestible marker. On the day before each ileal collection, feces were collected via rectal palpation at 0700 and 1900. Fecal collection was followed by quantitative collection of ileal digesta. For each pig, ileal digesta was collected continuously for two 24-h periods into a plastic bag attached to the cannula using a polyethylene vinyl chloride 90° elbow. Digesta was collected at least once per hour, frozen using liquid N, and stored frozen. There was a 6-d period between ileal collections, and, upon completion of the second ileal collection for each pig, feeding of the next allotted treatment diet began. Ileal digesta from the two collections from each pig were combined and subsampled, and the subsamples were then lyophilized and ground for chemical analyses. Fecal samples from the two collections from each pig were combined, lyophilized, and ground for chemical analyses. Feed from each treatment period was sampled and ground for chemical analyses.
Feed, ileal digesta, and feces were analyzed for DM (AOAC, 1990) and for Kjeldahl N using a Technicon Autoanalyzer II (Technicon Instruments Corp., Tarrytown, NY) after digestion on a block digester. Gross energy was determined on these samples using oxygen bomb calorimetry (Parr Co. Oxygen Bomb Calorimeter, Model NO 13031, Moline, IL). Feed and ileal digesta were analyzed for starch (Thivend et al., 1972), NDF (Goering and Van Soest, 1970), and fat (AOAC, 1990). After a nitric acid wet digestion, feed, ileal, and excreta samples were analyzed for Ca and P content by inductively coupled plasma emission spectrometry (Model Optima 3000, Perkin Elmer, Norwalk, CT). Amino acids (Phe, Val, Thr, Trp, Ile, His, Arg, Lys, and Leu) in the feed and ileal digesta were analyzed (AOAC, 1990) on an AA analyzer (Beckman 6300 Series, Beckman Instruments, Inc., Palo Alto, CA). For all amino acids except Trp, feed and ileal digesta samples (approximately 200 mg) were placed into 20- x125-mm glass tubes with Teflon-lined screw caps and hydrolyzed for 24 h at 110°C in 6 N HCl under a N atmosphere in a forced-air oven. For Trp, the samples were placed in 30 x 105-mm polyallomer tubes with Teflon-lined screw caps and hydrolyzed for 20 h at 110°C in 4.2 N NaOH under a N atmosphere. A standard sample was run with each batch of amino acid analysis, and, if the average deviation of the test samples vs. the standard was 
5%, the values were accepted; otherwise they were rerun. Amino acid concentrations were not corrected for incomplete recovery resulting from hydrolysis. Chromium concentrations were determined by atomic absorption spectrometry (Williams et al., 1962) to allow calculation of apparent ileal and total-tract digestibility of CP, GE, and DM and ileal digestibility of AA, fat, starch, and NDF. Apparent large intestinal digestibility coefficients were determined by subtracting the apparent ileal digestibility coefficients from the apparent fecal digestibility coefficients.
The kilocalories of energy that could be attributed to digestible CP were determined by the following equations:
 |
where Ndig = percentage of digestible N, (N)feed = N concentration of the feed (%), ADN = apparent digestibility (%) of N, 6.25 = conversion from N to crude protein (NRC, 1998), and 5.6 is the number of calories per gram of protein (Ewan, 2001).
Data were analyzed as a Latin rectangle with eight columns and four rows (Kuehl, 1994). Treatment means were separated with orthogonal contrasts appropriate for a 2 x 2 factorial arrangement of treatments using the GLM procedure of SAS (SAS Inst. Inc., Cary, NC). In addition, a single-degree-of-freedom comparison of Diet 1 vs. Diet 4 was made. Treatment differences were considered significant at = 0.10.
Experiment 2
Sixteen (eight per treatment) purebred Yorkshire or crossbred (Yorkshire x Landrace; Yorkshire x Landrace x Duroc) barrows (initial BW of 53 kg) were allotted to treatments in a completely randomized design. They were penned individually in the 0.6- x 1.2-m polyvinyl chloride metabolism crates used in Exp. 1. Before surgery, pigs were fed to appetite the C-SBM basal diet mixed with water, and water was available ad libitum between feedings. Six days before conducting the feeding challenge, a catheter was surgically inserted into the anterior vena cava of each pig as described by Amoikon et al. (1995). Pigs were allowed a 3-d adjustment period after catheterization before the treatment diets were fed.
The dietary treatments were 1) C-SBM (Ca and aP were 0.50 and 0.19%) or 2) C-SBM + 500 phytase units/kg diet (Ca and aP were 0.38 and 0.07%; Natuphos 600; BASF Corp). Analysis of the diets for phytase indicated that Diet 1 contained no phytase and Diet 2 contained 520 phytase units/kg (Chen, 1996). A C-SBM basal diet (Table 1) low in Ca and aP was formulated, and, as in Exp. 1, monocalcium phosphate, limestone and sand, and/or phytase were changed to achieve the treatment diets. Diets provided 0.77% total Lys and met or exceeded all other nutrient requirements for growing pigs (NRC, 1998). Feed was mixed with water and fed to appetite at 0800 and 1600 daily. The experimental diets were fed for 3 d before the feeding challenge was conducted. Water was provided on an ad libitum basis throughout the experiment. The pigs were held without feed for 16 h before the feeding challenge was conducted.
For the feeding challenge, blood samples were collected at -60, -30, and 0 min before the pigs were fed. At time 0, all pigs were simultaneously fed their experimental diets at 2% of BW, and an amount of water equal to the amount of feed was added to their meal. Fifteen minutes later, the same amount of water was added to the meal. All pigs consumed their meal within 30 min after the initiation of feeding. Blood samples were then collected at 10, 20, 30, 40, 50, 60, 75, 90, 105, 120, 150, 180, 210, 240, 270, and 300 min after the start of the meal. Blood samples were collected into a 4-mL Vacutainer containing 8.0 mg of potassium oxalate and 10.0 mg of sodium fluoride and then refrigerated. Samples were centrifuged for 20 min at 1,500 x g at 4°C, and plasma was collected and frozen until subsequent analyses. Plasma was analyzed for glucose (Sigma, 1990), insulin (Coat-a-Count; Diagnostic Products Corp., Los Angeles, CA), urea N (Laborde et al., 1995), and NEFA (NEFA-C Kit, ACS-ACOD Method; Waco Chemicals USA, Inc., Richmond, VA) concentrations. Total -amino N concentrations were determined by the TNBS (2,4,6-trinitrobenzene 1-sulfonic acid) spectrophotometric procedure, which was based on the procedures from Satake et al. (1960). Clearance rate (percentage/min) and half-life (min) of NEFA were calculated between 0 and 10 min after feeding. Area under the response curve for glucose, insulin, NEFA, PUN, and total -amino N were determined using trapezoidal geometry (0 to 300 min) and the -60-, -30-, and 0-min samples were used to establish the baseline.
Data were analyzed by analysis of variance procedures appropriate for a completely randomized design (Steel and Torrie, 1980) using the GLM procedure of SAS (SAS Inst. Inc., Cary, NC). Average plasma concentrations and areas under the response curve for glucose, insulin, NEFA, PUN, and total -amino N and clearance and half-life of NEFA were analyzed with treatment in the model. Glucose, insulin, NEFA, PUN, total -amino N, and insulin:glucose concentrations over time were analyzed with treatment, time, and treatment x time in the model. The individual pig served as the experimental unit for all data. Treatment differences were considered significant at = 0.10. This -level was chosen to provide a power of 80% based on an expected difference between means of 5%, an expected CV of 5%, and with eight observations per treatment.
Results
Experiment 1
The main effect of reducing the Ca and P concentration in the diet increased (P < 0.10) the ileal digestibility of Lys, Ile, Leu, Phe, Arg, Val, and Thr and the average digestibility of all AA (Table 2). Phytase addition increased (P < 0.10) the ileal digestibility of Ile and Leu. Phytase also increased the digestibility of Ile and Thr, but the effect was more pronounced in diets with reduced levels of Ca and P (phytase x Ca and P, P < 0.10). Because phytase will most often be supplemented to diets with a concomitant reduction of dietary Ca and P, a comparison of Diets 1 vs. 4 was made. Compared with the control diet (Diet 1), phytase addition along with the reduction in Ca and P in the diet (Diet 4) increased (P < 0.10) the ileal digestibility of all AA and the average ileal AA digestibility.
|
). Phytase supplementation increased (P < 0.08) the ileal digestibility of DM, starch, Ca, and P. Phytase also increased the ileal digestibility of NDF but only in diets with adequate levels of Ca and P (phytase x Ca and P, P < 0.10). The combination of dietary phytase supplementation and reducing the level of Ca and P (Diet 4) in the diet increased (P < 0.04) the ileal digestibility of DM, starch, GE, and Ca compared with the control diet (Diet 1).
|
Phytase supplementation decreased (P < 0.07) large intestinal digestibility of N and DM, and reducing the Ca and P in the diet decreased (P < 0.08) large intestinal digestibility of N and GE. Phytase supplementation and reducing the Ca and P in the diet reduced large intestinal digestibility of DM and GE, but the responses were not additive (phytase x Ca and P, P < 0.10). The combination of dietary phytase supplementation and reducing the level of Ca and P (Diet 4) in the diet decreased (P < 0.04) large intestinal digestibility of DM and GE compared with the control diet (Diet 1).
Energy (kcal/kg of diet; Table 4) digested from the ileum and energy digested from the ileum and corrected for the amount of DE from crude protein was higher (P < 0.08) in pigs fed diets with reduced (P < 0.10) levels of Ca and P. However, large intestinal digestibility of these response variables was reduced in pigs fed the diets with reduced levels of Ca and P. Phytase supplementation and reducing the level of Ca and P in the diet increased the digestibility of energy digested from the ileum and corrected for the amount of DE from crude protein, but the response was not additive (phytase x Ca and P, P < 0.10). Phytase and reducing the level of Ca and P in the diet decreased the digestibility of energy digested from the large intestine and corrected for the amount of DE from crude protein, but again the response was not additive (phytase x Ca and P, P < 0.10). Compared with the control diet, pigs fed Diet 4 had an increased (P < 0.04) digestibility of DE and DE corrected for CP in the ileum but a decreased (P < 0.06) digestibility of these response variables in the large intestine.
|
). Plasma glucose concentrations for pigs fed both diets peaked 30 min after the initiation of the meal (Figure 1A). Pigs fed supplemental phytase had higher plasma glucose concentrations throughout the remainder of the feeding challenge compared with pigs fed the control diet. Plasma insulin concentrations were increased (P < 0.05) by phytase addition, but insulin area under the response curve was not affected. Plasma insulin concentrations also peaked approximately 30 min after feeding; however, plasma insulin concentrations in pigs fed phytase returned to the level of the control pigs 60 min after the initiation of the meal and remained constant throughout the remainder of the feeding challenge (Figure 1B). Phytase addition to the diet did not affect insulin:glucose ratio or NEFA concentrations, clearance, or half-life, but phytase addition decreased (P < 0.02) NEFA area under the response curve. However, pigs fed phytase had higher levels of NEFA concentrations before the initiation of the feeding challenge (Figure 2A). Plasma NEFA concentrations in pigs fed both diets began decreasing at the same time and at the same rate immediately following the initiation of the meal, reaching a constant level at approximately 30 min postfeeding. Plasma urea N concentrations were increased (P < 0.01) by phytase, but pigs fed phytase had higher PUN concentrations both before and throughout the feeding challenge (Figure 2B). Plasma urea N area under the response curve was not affected by phytase addition. Plasma total -amino N concentrations were increased (P < 0.03) by phytase addition (Figure 2C), and, as was similar to PUN, -amino N concentrations were higher (P < 0.03) in pigs fed phytase before the initiation of the meal. Plasma total a-amino N concentrations in pigs fed phytase increased at a faster rate after the initiation of the feeding challenge compared with the control group but then followed a similar pattern 30 min postfeeding.
|
|
|
Phytate is a compound with known antinutritional effects. The most noted effect is that phytate P has limited availability in diets for swine and poultry (Nelson et al., 1968; Calvert et al., 1978). Phytate also negatively affects protein quality (Satterlee and Abdul-Kadir, 1983) and AA availability in feeds (Ravindran et al., 1999), and it inhibits trypsinogen activation (Caldwell, 1992). Dietary phytase has been shown to reduce some of the negative effects of phytate. Research has shown that phytase increases apparent ileal digestibility of AA and N in pigs (Biehl and Baker, 1996; Radcliffe et al., 1999; Zhang and Kornegay, 1999), chicks (Sebastian et al., 1997; Ravindran and Bryden, 1999; Ravindran et al., 2000), and poults (Yi et al., 1996a). Our data with phytase addition combined with a reduction in dietary Ca and P support these findings. We also report in this experiment that phytase supplementation along with a reduction in dietary Ca and P increases plasma urea and -amino N concentrations in pigs after the consumption of a meal. These increases in plasma N metabolites support the increase in ileal N and AA digestibility. Because our diets were formulated to be adequate in AA, the increase in protein availability by phytase would have provided excess AA, which would have resulted in an increase in AA deamination and therefore, an increase in urea formation. O’Quinn et al. (1997) reported that phytase did not affect ileal N digestibility.
Starch digestibility is inversely related to phytate intake (Yoon et al., 1983; Thompson et al., 1987; Thompson, 1988). Phytate may affect starch digestion by 1) binding with proteins that are closely associated with starch; 2) inhibiting the activity of digestive enzymes; 3) chelating Ca, which is required for amylase activity; or 4) direct binding with starch (Deshpande and Cheryan, 1984; Thompson, 1988). Thompson et al. (1987) reported that removal of phytate from navy bean flour in the form of unleavened bread increased in vitro starch digestibility and blood glucose response in humans, whereas addition of phytate to the dephytinized flour reversed this response. Our data support these responses. Phytase supplementation and phytase addition combined with a dietary reduction in Ca and P increased ileal starch digestibility, and this increase in digestibility was supported by an increase in plasma glucose and insulin concentrations after a meal. Nonesterified fatty acid concentrations typically decrease when pigs initiate consumption of a meal, and it is assumed that this decrease is due to the presence of glucose in the blood. However, plasma NEFA concentrations, clearance, or half-life were not affected by phytase supplementation in this study.
Fat digestibility was not significantly affected by phytase. However, Cosgrove (1966) reported that phytate binds with lipids, and Ravindran and Bryden (1999) reported that Ca-phytate complexes with fatty acids in the gut lumen to form insoluble metallic soaps, thereby reducing fat digestibility.
Ileal NDF digestibility was increased when pigs were fed phytase in the adequate Ca and P diet but not in the diet deficient in Ca and aP. We have no explanation for this response. These data are not in agreement with Bruce and Sundstol (1995), who reported that ileal digestibility of crude fiber was not affected by phytase in pigs fed a high-fiber diet. These researchers also reported that fecal digestibility of fiber was lower in diets containing microbial phytase.
Dry matter digestibility was increased by phytase and by the reduction in Ca and aP. This response is not surprising in that AA and starch digestibility were increased by phytase in combination with a dietary reduction in Ca and P. Jongbloed et al. (1992) and O’Quinn et al. (1997) reported that dietary phytase addition did not affect ileal DM digestibility. Total-tract DM digestibility was not affected by phytase, which agrees with Jongbloed et al. (1992), Kemme et al. (1997), and O’Quinn et al. (1997) but not with Mroz et al. (1994), who reported that phytase increased total-tract digestibility of DM and CP.
The increase in DM, starch, and AA digestibility for phytase and the dietary reduction of Ca and P resulted in an increase in apparent ileal DE. Most of the increase in AA digestibility will be used for protein accretion and will not be available for use as an energy source. However, DE corrected for energy from digested CP also was increased.
Ileal digestibility of Ca and P were higher in pigs fed phytase, which is in agreement with numerous reports (Jongbloed et al., 1992; Radcliffe et al., 1995, 1999; Zhang and Kornegay, 1999). Total-tract Ca and P digestibilities were increased by phytase. As expected, ileal and total-tract P digestibilities were decreased when the inorganic P source was removed from the diet.
Dry matter, GE, and DE digestibilities were greater in the large intestine for pigs fed the control diet than for pigs fed the diet with added phytase and a reduction in dietary Ca and P. Nitrogen digestibility in the large intestine was greater in the control diet than in the other diets. These responses were likely due to increased substrate availability for bacterial digestion in the large intestine because of lower ileal digestibility of these nutrients in the control diet compared with the other diets. The increased N digestibility in the large intestine accounts for some of the increase in energy digestibility. There was no effect of diet on large intestinal digestibility of Ca or P.
Increased digestibility in the large intestine due to dietary phytase addition would not be anticipated, as Jongbloed et al. (1992) reported that there was no phytase activity in ileal digesta of pigs fed phytase. However, these responses are in contrast to O’Quinn et al. (1997), who reported increases in both Ca and P digestibility in the large intestine with phytase addition. Regardless of diet, phytase activity from the microbial population in the large intestine would have been more important than dietary supplemental phytase as it relates to phytase effects in the large intestine.
In our experiment, the reduction in dietary Ca and P was just as effective, if not more so, as dietary phytase supplementation in increasing the digestibility of nutrients. Other research has shown that mineral concentrations in diets for nonruminants have an effect on nutrient availability. Yi et al. (1996a) reported increased apparent and true ileal digestibilities of essential AA and N when dietary non-phytate P concentration was decreased from 0.60 to 0.45% in diets for poults. Näsi (1990) reported that apparent total-tract digestibility of CP was greater in pigs receiving diets without an inorganic P supplement. Atteh and Leeson (1984) reported increased formation of insoluble soaps between Ca and dietary fats as dietary Ca concentration was increased. These reports support our results where reducing the Ca and P in the diet without the addition of phytase increased apparent ileal AA, N, starch, DM, and GE digestibilities. However, Yi et al. (1996b) reported that apparent total-tract digestibility of DM and apparent absorption of N decreased linearly as the amount of aP increased without the addition of phytase to diets for swine. Their report is in contrast to the current experiment where reducing Ca and P had no effect on apparent total-tract DM, GE, or N digestibilities.
Reducing the dietary Ca and P concentrations without the addition of phytase increased nutrient digestibilities, but this is not a practical option. Inadequate Ca and P concentrations during the growing and early finishing phases of production will decrease feed intake (Combs et al., 1991) and inadequate P will decrease gain (Cromwell et al., 1995). However, Mavromichalis et al. (1999) reported that decreasing the P in the diet to 0.40% for the last 30 d of the finishing period increased ADG, but it had no effect on ADFI, gain feed, or meat quality.
The combination of phytase addition and Ca and P reduction increased apparent ileal AA, N, starch, DM, Ca, P, and GE digestibilities. These responses were supported by increased plasma glucose and insulin concentrations after the consumption of a meal.
Implications
These data indicate that phytase addition along with a reduction in dietary calcium and phosphorus increases amino acid and energy digestibility in corn-soybean meal diets for pigs, and that when phytase is used in diet formulations, dietary concentrations of amino acids and energy can be reduced.
Footnotes
1 Approved for publication by the Director of the Louisiana Agric. Exp. Stn. as manuscript No. 02-18-0771. 
2 Research supported in part by BASF Corp., Mount Olive, NJ 07828.
3 The authors thank L. Camp, J. Shelton, R. Payne, A. Guzik, D. Gantt, E. Shelton, and S. Radcliffe for their assistance with these experiments.
4 Presented in part at the 8th Symp. on Digestive Physiology in Pigs, June 20-22, 2000, Uppsala, Sweden.
6 Present address: Archer Daniels Midland Co., Quincy, IL 62305.
5 Correspondence—e-mail: lsouthern{at}agctr.lsu.edu.
Received for publication February 13, 2003. Accepted for publication November 6, 2003.
Literature Cited
Amoikon, E. K., J. M. Fernandez, L. L. Southern, D. L. Thompson, Jr., T. L. Ward, and B. M. Olcott. 1995. Effect of chromium tripicolinate on growth, glucose tolerance, insulin sensitivity, plasma metabolites, and growth hormone in pigs. J. Anim. Sci. 73:1123–1130.[Abstract]
AOAC. 1990. Official Methods of Analysis. 15th ed. Assoc. Offic. Anal. Chem. Arlington, VA.
Atteh, J. O., and S. Leeson. 1984. Effects of dietary saturated or unsaturated fatty acids and calcium levels on performance and mineral metabolism of broiler chicks. Poult. Sci. 63:2252–2260.[Medline]
Biehl, R. R., and Baker, D. H. 1996. Efficacy of supplemental 1-hydroxycholecalciferol and microbial phytase for young pigs fed phosphorus- or amino acid-deficient corn-soybean meal diets. J. Anim. Sci. 74:2960–2966.[Abstract]
Bruce, J. A. M., and F. Sundstl. 1995. The effect of microbial phytase in diets for pigs on apparent ileal and faecal digestibility, pH and flow of digesta measurements in growing pigs fed a high-fibre diet. Can. J. Anim. Sci. 75:121–127.
Caldwell, R. A. 1992. Effect of calcium and phytic acid on the activation of trypsinogen and the stability of trypsin. J. Agric. Food Chem. 40:43–46.
Calvert, C. C., R. J. Besecke, M. P. Plumlee, T. R. Cline, and D. M. Forsyth. 1978. Apparent digestibility of phosphorus in barley and corn for growing swine. J. Anim. Sci. 47:420–426.
Chen, J., 1996. Phytase assay in straight products, premixes and feeds. Pages 649–654 in Phytase in Animal Nutrition and Waste Management. M. B. Coelho and E. T. Kornegay, ed. BASF Corp., Mt. Olive, NJ.
Combs, N. R., E. T. Kornegay, M. D. Lindemann, and D. R. Notter. 1991. Calcium and phosphorus requirement of swine from weaning to market weight: I. Development of response curves for performance. J. Anim. Sci. 69:673–681.[Abstract]
Cosgrove, D. J. 1966. The chemistry and biochemistry of inositol polyphosphates. Rev. Pure Appl. Chem. 16:209–224.
Cromwell, G. L., R. D. Coffey, G. R. Parker, H. J. Monegue, and J. H. Randolph. 1995. Efficacy of a recombinant-derived phytase in improving the bioavailability of phosphorus in corn-soybean meal diets for pigs. J. Anim. Sci. 73:2000–2008.[Abstract]
Deshpande, S. S., and M. Cheryan. 1984. Effects of phytic acid, divalent cations, and their interactions on -amylase activity. J. Food Sci. 49:516–524.
Ewan, R. C. 2001. Energy utilization in swine nutrition. Page 85 in Swine Nutrition, 2nd ed. A. J. Lewis and L. L. Southern, ed. CRC Press, Boca Raton, FL.
Goering, H. K., and P. J. Van Soest. 1970. Forage Fiber Analysis (Apparatus, Reagents, Procedures, and Some Applications). Agric. Handbook 379. ARS-USDA, Washington, DC.
Jongbloed, A. W., Z. Mroz, and P. A. Kemme. 1992. The effect of supplementary Aspergillus niger phytase in diets for pigs on concentration and apparent digestibility of dry matter, total phosphorus, and phytic acid in different sections of the alimentary tract. J. Anim. Sci. 70:1159–1168.[Abstract]
Kemme, P. A., J. S. Radcliffe, A. W. Jongbloed, and Z. Mroz. 1997. Factors affecting phosphorus and calcium digestibility in diets for growing-finishing pigs. J. Anim. Sci. 75:2139–2146.
Knuckles, B. E., and A. A. Betschart. 1987. Effect of phytate and other myo-inositol phosphate esters on -amylase digestion of starch. J. Food Sci. 52:719–721.
Kuehl, R. O. 1994. Statistical Principles of Research Design and Analysis. Duxbury Press. Belmont, CA.
Laborde, C. J., A. M. Chapa, D. W. Burleigh, D. J. Salgado, and J. M. Fernandez. 1995. Effects of processing and storage on the measurement of nitrogenous compounds in ovine blood. Small Ruminant Res. 17:159–166.
Lei, X. G., P. K. Ku, E. R. Miller, and M. T. Yokoyama. 1993. Supplementing corn-soybean meal diets with microbial phytase linearly improves phytate phosphorus utilization by weanling pigs. J. Anim. Sci. 71:3359–3367.[Abstract]
Mavromichalis, I., J. D. Hancock, I. H. Kim, B. W. Senne, E. H. Kropf, G. A. Kennedy, R. H. Hines, and K. C. Behnke. 1999. Effects of omitting vitamin and trace mineral premixes and(or) reducing inorganic phosphorus additions on growth performance, carcass characteristics, and muscle quality in finishing pigs. J. Anim. Sci. 77:2700–2708.
Mroz, Z., A. W. Jongbloed, and P. A. Kemme. 1994. Apparent digestibility and retention of nutrients bound to phytate complexes as influenced by microbial phytase and feeding regimen in pigs. J. Anim. Sci. 72:126–132.[Abstract]
Mroz, Z., G. C. M. Bakker, A. W. Jongbloed, R. A. Dekker, R. Jongbloed, and A. van Beers. 1996. Apparent digestibility of nutrients in diets with different energy density, as estimated by direct and marker methods for pigs with or without ileo-cecal cannulas. J. Anim. Sci. 74:403–412.
Näsi, M. 1990. Microbial phytase supplementation for improving availability of plant phosphorus in the diet of the growing pigs. J. Agric. Sci. Finl. 62:435–442.
Nelson, T. S., T. R. Shieh, R. J. Wodzinski, and J. H. Ware. 1968. The availability of phytate phosphorus in soybean meal before and after treatment with a mold phytase. Poult. Sci. 47:1842–1848.[Medline]
NRC. 1998. Pages 111–123 in Nutrient Requirements of Swine. 10th rev. ed. Natl. Acad. Press, Washington, DC.
O’Quinn, P. R., D. A. Knabe, and E. J. Gregg. 1997. Efficacy of Natuphos® in sorghum-based diets of finishing swine. J. Anim. Sci. 75:1299–1307.
Radcliffe, J. S., E. T. Kornegay, and D. E. Conner, Jr. 1995. The effect of phytase on calcium release in weanling pigs fed corn-soybean meal diets. J. Anim. Sci. 73(Suppl. 1):173. (Abstr.)
Radcliffe, J. S., E. T. Kornegay, and R. S. Pleasant. 1999. Effects of microbial phytase on amino acid and mineral digestibilities in pigs fitted with steered ileo-cecal valve cannulas and fed a low protein, corn-soybean meal based diet. J. Anim. Sci. 77(Suppl. 1):175. (Abstr.)
Ravindran, V., and W. L. Bryden. 1999. Effect of enzymes on amino acid and energy digestibility in poultry. Proc. BioKyowa Amino Acid Council. St. Louis, MO.
Ravindran, V., S. Cabahug, G. Ravindran, and W. L. Bryden. 1999. Influence of microbial phytase on apparent ileal amino acid digestibility of feedstuffs for broilers. Poult. Sci. 78:699–706.
Ravindran, V., S. Cabahug, G. Ravindran, P. H. Selle, and W. L. Bryden. 2000. Response of broiler chickens to microbial phytase supplementation as influenced by dietary phytic acid and non-phytate phosphorus levels. II. Effects on apparent metabolisable energy, nutrient digestibility and nutrient retention. Br. Poult. Sci. 41:193–200.[Medline]
Satake, K., T. Okuyama, M. Ohashi, and T. Shinoda. 1960. The spectrophotometric determination of amine, amino acid and peptide with 2,4,6-trinitrobenzene 1-sulfonic acid. J. Biochem. 47:654–660.
Satterlee, L. D., and R. Abdul-Kadir. 1983. Effect of phytate content on protein nutritional quality of soy and wheat bran proteins. Lebensm.-Wiss. Technol. 16:8–14.
Sebastian, S., S. P. Touchburn, E. R. Chavez, and P. C. Lague. 1997. Apparent digestibility of protein and amino acids in broiler chickens fed a corn-soybean diet supplemented with microbial phytase. Poult. Sci. 76:1760–1769.
Sigma. 1990. Glucose (Trinder). Quantitative, Enzymatic Determination of Glucose in Serum or Plasma at 505 nm. Tech. Bull. No. 315. Sigma Chemical Co., St. Louis, MO.
Steel, R. G. D., and J. H. Torrie. 1980. Principles and Procedures of Statistics: A Biometrical Approach. 2nd ed. McGraw-Hill, New York.
Thivend, P., C. Merier, and A. Guilbot. 1972. Determination of starch with glucoamylase. Pages 100–105 in Methods in Carbohydrate Chemistry. Vol. 6. R. L. Whistler and J. N. BeMiller, ed. Academic Press, New York.
Thompson, L. U. 1988. Antinutrients and blood glucose. Food Technol. 42:123–132.
Thompson, L. U., C. L. Button, and D.J.A. Jenkins. 1987. Phytic acid and calcium affect the in vitro rate of navy bean starch digestion and blood glucose response in humans. Am. J. Clin. Nutr. 46:467–473.
Thompson, L. U., and J. H. Yoon. 1984. Starch digestibility as affected by polyphenols and phytic acid. J. Food Sci. 49:1228–1229.
Traylor, S. L., G. L. Cromwell, M. D. Lindemann, and D. A. Knabe. 2001. Effects of level of supplemental phytase on ileal digestibility of amino acids and minerals in soybean meal for pigs. J. Anim. Sci. 79:2634–2642.
Williams, C. H., D. J. David, and D. Iismaa. 1962. The determination of chromic oxide in feces samples by atomic absorption spectrophotometry. J. Agric. Sci. 59:381–385.
Yi, Z., E. T. Kornegay, and D.M. Denbow. 1996a. Effect of microbial phytase on nitrogen and amino acid digestibility and nitrogen retention of turkey poults fed corn-soybean meal diets. Poult. Sci. 75:979–990.[Medline]
Yi, Z., E. T. Kornegay, V. Ravindran, M. D. Lindemann, and J. H. Wilson. 1996b. Effectiveness of Natuphos® phytase in improving the bioavailabilities of phosphorus and other nutrients in soybean meal-based semipurified diets for young pigs. J. Anim. Sci. 74:1601–1611.[Abstract]
Yoon, J. H., L. U. Thompson, and D. J. A. Jenkins. 1983. The effect of phytic acid on in vitro rate of starch digestibility and blood glucose response. Am. J. Clin. Nutr. 38:835–842.
Zhang, Z., and E. T. Kornegay. 1999. Phytase effects on ileal amino acid digestibility and nitrogen balance in finishing pigs fed a low-protein plant-based diet. J. Anim. Sci. 77(Suppl. 1):175. (Abstr.)
This article has been cited by other articles:
|
|
 |
|
  S. L. Johnston, E. D. Fruge, T. D. Bidner, and L. L. Southern Effect of Phytase Addition on Growth and Carcass Traits of Pigs Fed Diets Deficient in Lysine, Calcium, and Phosphorus Professional Animal Scientist, April 1, 2009; 25(2): 169 - 174. [Abstract] [PDF]
|
|
|
|
 |
|
 H. H. Stein, C. T. Kadzere, S. W. Kim, and P. S. Miller Influence of dietary phosphorus concentration on the digestibility of phosphorus in monocalcium phosphate by growing pigs J Anim Sci, August 1, 2008; 86(8): 1861 - 1867. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Pomar, F. Gagne, J. J. Matte, G. Barnett, and C. Jondreville The effect of microbial phytase on true and apparent ileal amino acid digestibilities in growing-finishing pigs J Anim Sci, July 1, 2008; 86(7): 1598 - 1608. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. L. Veum and M. R. Ellersieck Effect of low doses of Aspergillus niger phytase on growth performance, bone strength, and nutrient absorption and excretion by growing and finishing swine fed corn-soybean meal diets deficient in available phosphorus and calcium J Anim Sci, April 1, 2008; 86(4): 858 - 870. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. A. Woyengo, J. S. Sands, W. Guenter, and C. M. Nyachoti Nutrient digestibility and performance responses of growing pigs fed phytase- and xylanase-supplemented wheat-based diets J Anim Sci, April 1, 2008; 86(4): 848 - 857. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. K. D. Nyannor, P. Williams, M. R. Bedford, and O. Adeola Corn expressing an Escherichia coli-derived phytase gene: A proof-of-concept nutritional study in pigs J Anim Sci, August 1, 2007; 85(8): 1946 - 1952. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. N. Nortey, J. F. Patience, P. H. Simmins, N. L. Trottier, and R. T. Zijlstra Effects of individual or combined xylanase and phytase supplementation on energy, amino acid, and phosphorus digestibility and growth performance of grower pigs fed wheat-based diets containing wheat millrun J Anim Sci, June 1, 2007; 85(6): 1432 - 1443. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. L. Veum, D. R. Ledoux, and V. Raboy Low-phytate barley cultivars improve the utilization of phosphorus, calcium, nitrogen, energy, and dry matter in diets fed to young swine J Anim Sci, April 1, 2007; 85(4): 961 - 971. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. A. Jendza, R. N. Dilger, J. S. Sands, and O. Adeola Efficacy and equivalency of an Escherichia coli-derived phytase for replacing inorganic phosphorus in the diets of broiler chickens and young pigs J Anim Sci, December 1, 2006; 84(12): 3364 - 3374. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. V. Brana, M. Ellis, E. O. Castaneda, J. S. Sands, and D. H. Baker Effect of a novel phytase on growth performance, bone ash, and mineral digestibility in nursery and grower-finisher pigs J Anim Sci, July 1, 2006; 84(7): 1839 - 1849. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. S. Radcliffe, R. S. Pleasant, and E. T. Kornegay Estimating equivalency values of microbial phytase for amino acids in growing and finishing pigs fitted with steered ileo-cecal valve cannulas J Anim Sci, May 1, 2006; 84(5): 1119 - 1129. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. L. Veum, D. W. Bollinger, C. E. Buff, and M. R. Bedford A genetically engineered Escherichia coli phytase improves nutrient utilization, growth performance, and bone strength of young swine fed diets deficient in available phosphorus J Anim Sci, May 1, 2006; 84(5): 1147 - 1158. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. A. Jendza, R. N. Dilger, S. A. Adedokun, J. S. Sands, and O. Adeola Escherichia coli phytase improves growth performance of starter, grower, and finisher pigs fed phosphorus-deficient diets J Anim Sci, August 1, 2005; 83(8): 1882 - 1889. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. K. Kies, W. J. J. Gerrits, J. W. Schrama, M. J. W. Heetkamp, K. L. van der Linden, T. Zandstra, and M. W. A. Verstegen Mineral Absorption and Excretion as Affected by Microbial Phytase, and their Effect on Energy Metabolism in Young Piglets J. Nutr., May 1, 2005; 135(5): 1131 - 1138. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. F. Liao, W. C. Sauer, A. K. Kies, Y. C. Zhang, M. Cervantes, and J. M. He Effect of phytase supplementation to diets for weanling pigs on the digestibilities of crude protein, amino acids, and energy J Anim Sci, March 1, 2005; 83(3): 625 - 633. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. L. Shelton, L. L. Southern, F. M. LeMieux, T. D. Bidner, and T. G. Page 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 J Anim Sci, September 1, 2004; 82(9): 2630 - 2639. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. L. Shelton, J. O. Matthews, L. L. Southern, A. D. Higbie, T. D. Bidner, J. M. Fernandez, and J. E. Pontif Effect of nonwaxy and waxy sorghum on growth, carcass traits, and glucose and insulin kinetics of growing-finishing barrows and gilts J Anim Sci, June 1, 2004; 82(6): 1699 - 1706. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
