Apparent Total Tract Digestibility Of Ca Research Articles

Effects of microbial phytase on the apparent and standardized total tract digestibility of phosphorus in rice coproducts fed to growing pigs.

The objectives of this experiment were to determine the apparent total tract digestibility (ATTD) and the standardized total tract digestibility (STTD) of P and the effect of microbial phytase on ATTD and STTD of P in full-fat rice bran (FFRB), defatted rice bran (DFRB), brown rice, broken rice, and rice mill feed when fed to pigs. Ninety-six barrows (initial BW of 19.4 ± 1.4 kg) were allotted to 12 diets with 8 replicate pigs per diet in a randomized complete block design. A basal diet based on corn and soybean meal was formulated. Five additional diets containing corn, soybean meal, and each rice coproduct were also formulated, and the ratio between corn and soybean meal in these diets was similar to that in the basal diet. Six additional diets that were similar to the initial 6 diets with the exception that 1,000 units of microbial phytase were added to the diets were also formulated. The ATTD and STTD of P were calculated for each diet using the direct procedure, and the ATTD and STTD of P in each rice coproduct were calculated using the difference procedure. Results of the experiment indicated that the concentration of P in feces was reduced (P < 0.05) from pigs fed diets with microbial phytase compared with pigs fed diets without phytase. No differences were observed between the basal diet and the broken rice diet, but the ATTD and the STTD of P in those diets was greater (P < 0.05) than in all other diets both without and with phytase. Among the rice coproducts, the greatest (P < 0.05) ATTD and STTD of P were observed for broken rice regardless of inclusion of phytase. If no microbial phytase was used, the values for STTD of P in brown rice, FFRB, DFRB, and rice mill feed were not different, but if microbial phytase was included in the diet, ATTD and STTD of P in brown rice was greater (P < 0.05) than in FFRB, DFRB, and rice mill feed. The STTD of P in brown rice, FFRB, and rice mill feed was greater (P < 0.05) if microbial phytase was used than if no microbial phytase was used. Addition of microbial phytase to the diets also increased (P < 0.05) the ATTD of Ca regardless of the rice coproducts used. In conclusion, the STTD of P is greater in broken rice than in all other rice coproducts. The STTD of P in brown rice, FFRB, DFRB, and rice mill feed is relatively low due to the high concentration of phytate in these ingredients, but addition of microbial phytase will increase the STTD of P in most rice coproducts.

Super High Dosing with a Novel Buttiauxella Phytase Continuously Improves Growth Performance, Nutrient Digestibility, and Mineral Status of Weaned Pigs.

This study was conducted to evaluate the efficacy of a novel Buttiauxella phytase to pigs fed P-deficient, corn-soybean meal diets. One hundred and twenty crossbred piglets (9.53 ± 0.84kg) were allocated to one of five treatments which consisted of four low P diets (0.61% Ca and 0.46% total P) supplemented with 0, 500, 1,000, or 20,000FTU/kg phytase as well as a positive control diet (0.77% Ca and 0.62% total P). Each treatment had six replicated pens with four pigs per pen. Pigs were fed the experimental diets for 28days. Phytase supplementation linearly improved (P < 0.05) average daily gain (ADG), feed conversion ratio (FCR), and apparent total tract digestibility (ATTD) of dry matter, gross energy, crude protein, Ca, and P in weaned pigs. Super high dosing with phytase (20,000FTU/kg) further increased (P < 0.05) ADG compared with 500FTU/kg phytase inclusion group, as well as ATTD of Ca and P. Metacarpal bone characteristics and several trace mineral concentration in bone, plasma, or organ tissues were linearly (P < 0.05) improved at increasing dose of phytase. Super high dosing with phytase (20,000FTU/kg) supplementation improved (P < 0.05) Mn and Zn concentration in bone compared to normal dose of phytase supplementation (500 or 1,000FTU/kg). In conclusion, supplementation of 500 FTU of Buttiauxella phytase/kg and above effectively hydrolyzed phytate in a low-P corn-soybean diet for pigs. In addition, a super high dosing with phytase (20,000FTU/kg) improved macro- or micro mineral availability and growth performance.

Nutrient digestibility in diets containing low-phytate barley, low-phytate field pea and normal-phytate field pea, and the effects of microbial phytase on energy and nutrient digestibility in the low and normal-phytate field pea fed to pigs

Five ileal cannulated barrows (43.6±1.3kg BW) were used in a 5×5 Latin square design experiment to determine the apparent (AID) and standardized (SID) ileal digestibility of N and amino acids (AA) in low-phytate field pea (LPP), low-phytate barley (LPB) and normal-phytate field pea (NPP) and the apparent total tract digestibility (ATTD) of Ca, P and energy in diets containing these ingredients. In addition, the effects of phytase supplementation (500FTU/kg) to diets containing LPP or NPP were determined. The experimental diets contained 869, 868 or 870g/kg LPB, LPP and NPP, respectively, as the sole source of N. The phytate P contents were 0.4, 0.7 and 2.0g/kg for LPB, LPP and NPP, respectively. Limestone was added to all diets meeting the recommended values, while inorganic P was added only in pea-based diets to provide 65% of the available P recommended by NRC (1998) for 20–50kg pigs. Titanium dioxide (3g/kg) was used as an indigestible marker. Daily feed allowance was calculated as 40g/kg BW at the beginning of each period and was offered in two equal meals at 0800 and 1600h. Each experimental period lasted for 8d; d 1–4 for adaptation, d 5–6 for urine and fecal collections, and d 7–8 for ileal digesta collection. The ATTD of DM and GE was not different among diets and was not affected by phytase addition. The ATTD of Ca and P was higher (P<0.05) in LPB than in LPP and NPP diets. Supplementing the LPP and NPP diets with phytase increased (P<0.05) the ATTD of Ca and P. The AID of N and all AA except Met were higher (P<0.05) in LPP and NPP than in LPB, but no difference between LPP and NPP were observed. Phytase supplementation increased (P<0.05) the AID for Arg, Ile, Leu, Phe, Pro, Ser, Tyr, and Val. The SID of AA in LPB, LPP, and NPP were 0.734, 0.895 and 0.895 for Lys, 0.732, 0.757 and 0.744 for Met and 0.755, 0.789 and 0.787 for Thr, respectively. Results indicate that both varieties of field pea had greater AID and SID of AA than LPB. Also, the LPP diet had higher ATTD of Ca and P compared with the NPP diet and phytase supplementation improved digestibility of P, Ca and some AA.

Effects of formulating growing pig diet with increasing levels of wheat‐corn distillers dried grains with solubles on digestible nutrient basis on growth performance and nutrient digestibility

Formulating swine diets containing fibrous coproducts based on net energy (NE) and standardized ileal digestible amino acid (SID AA) values is recommended for optimizing pig performance. However, the effects of applying this approach to diets with increasing dietary levels of wheat-corn-derived distillers dried grains with soluble (wcDDGS) on pig performance have not been evaluated. Thus, 48 pigs with an average body weight [BW] of 25.5kg were used to determine the effects of increasing wcDDGS (1:1 wheat to corn ratio) content in grower diets on performance and apparent total tract digestibility (ATTD) of energy and nutrients. Pigs were housed in pens of either 2 barrows or gilts balanced for BW and fed 4 diets within sex for 42days. Diets were a nutrient adequate corn-barley-soybean meal-based diet with 0%, 10%, 20% and 30% wcDDGS, and were similar in calculated NE and SID AA values. Acid insoluble ash was used as the indigestible marker. Final BW and overall average daily gain (ADG) linearly decreased (p<0.05) and feed efficiency tended to decrease (p=0.07) with increased dietary wcDDGS. Overall average daily feed intake was not affected (p>0.10) by dietary treatment. The ATTD of dry matter and energy linearly decreased (p<0.01), whereas the ATTD of neutral detergent fibre linearly increased (p<0.01) with increasing dietary level of wcDDGS. Increasing dietary wcDDGS content did not affect (p>0.10) ATTD of Ca and P. In conclusion, increasing dietary wcDDGS content reduced growth performance and ATTD of energy in growing pigs. Thus, the risks of high dietary wcDGGS content may not be completely alleviated by formulating growing pig diets on the basis of NE and SID AA systems.

Digestibility of phosphorus and calcium in meat and bone meal fed to growing pigs1

Seventy-two growing pigs (initial BW: 18.0 ± 1.6 kg) were used to determine the apparent total tract digestibility (ATTD) of P and Ca and the standardized total tract digestibility (STTD) of P in 8 different sources of meat and bone meal (MBM) and to develop equations to predict digestibility of P and Ca in MBM. Pigs were housed individually in metabolism cages and were randomly allotted to 9 diets with 8 replicate pigs per diet. Eight diets were formulated by mixing cornstarch, sucrose, soybean oil, sodium chloride, vitamin-mineral premix, and 8% of each source of MBM, and MBM was the sole source of P and Ca in each diet. A P-free diet was used to measure basal endogenous P losses (EPL) by the pigs. Feces were collected for 5 d based on the marker to marker approach after a 5-d adaptation period. On an as-fed basis, the concentration of P in the MBM sources ranged from 2.6 to 5.3% with an average of 4.3 ± 0.8% whereas Ca concentration ranged from 5.1 to 11.0% with an average of 9.2 ± 2.0%. The variation among MBM samples in Ca and P concentrations was calculated (CV = 22.1 and 20.0%, respectively) as was the variation in the concentration of other chemical components (CV = 6.2, 10.5, and 13.8% for CP, acid-hydrolyzed ether extract, and ash, respectively). The ATTD of P (52.1 to 80.1%, average = 65.9 ± 8.8%) and Ca (53.0 to 81.0%, average = 63.9 ± 9.4%) differed (P < 0.05) among MBM sources. The basal EPL was measured at 106 ± 51 mg/kg DMI in pigs fed the P-free diet. The STTD of P was different (54.8 to 84.4%; average = 68.8 ± 9.3%; P < 0.05) among MBM sources. The ATTD of Ca and the STTD of P decreased (P < 0.01) as ash, Ca, and P concentration in MBM increased, and the ATTD of Ca was positively related (R(2) = 0.99, P < 0.001) with the STTD of P. The STTD of P (%) in MBM may be predicted as 107.857 - 8.8 × total P [R(2) = 0.68, root mean square error (RMSE) = 5.73, P < 0.01] whereas ATTD of Ca (%) may be predicted as 105.375 - 9.327 × total P (R(2) = 0.75, RMSE = 4.70, P < 0.01). In conclusion, P and Ca digestibility varies among sources of MBM, but prediction equations using the concentration of total P in MBM may be used to estimate P and Ca digestibility in MBM fed to growing pigs.

Phytase improves apparent total tract digestibility of phosphorus and calcium in piglets fed diets with adequate or reduced phosphorus content

The effect of a thermotolerant 6-phytase produced by Trichoderma reesei on performance and apparent total tract digestibility (ATTD) of P and Ca was evaluated in 192 weaned piglets (randomized block design; 16 replicates; 2 piglets each). Diets based on wheat (Triticum aestivum), barley (Hordeum vulgare), oat (Avena sativa), soybean (Glycine max) meal, and whey protein with adequate [positive control (PC)] or reduced [negative control (NC)] Ca and P levels were fed for 46 d after weaning. The PC and NC diets contained 8.0 and 6.4 g/kg Ca and 2.9 and 1.9 g/kg digestible P, respectively. Pelleted diets contained 0, 500, or 1000 phytase units (FTU)/kg. Growth performance and G:F were measured during starter (25 d) and weaner pig (21 d) periods. The ATTD of Ca and P was determined by spot sampling at the end of the weaner pig period (8 pens per treatment over 5 consecutive d). Data were analyzed using a mixed model with random block effect and fixed effect of dietary P and phytase level and their interaction. Dietary P level did not affect ADG or G:F of piglets over the entire feeding period (P > 0.10) whereas phytase increased G:F (P < 0.05). During the starter period, phytase linearly enhanced (P < 0.05) ADG (258, 266, and 292 g) and G:F (639, 677, and 664 g gain/kg feed DM) without further increase in the weaner pig period (P > 0.10). A P × phytase interaction (P < 0.05) was observed for ATTD of P, more so for NC (48, 61, and 68%, respectively) than PC diets (52, 62, and 61%). The ATTD of Ca was higher (P < 0.05) for PC than NC diets (68 vs. 58%) and increased quadratically by phytase (61, 65, and 63%). In conclusion, the phytase tested enhanced piglet performance during the postweaning period and increased ATTD of P and Ca.

Performance and apparent total tract phosphorus and calcium digestibility in grower–finisher pigs fed diets with and without phytase

The efficacy of a thermotolerant 6-phytase on performance and apparent total tract digestibility (ATTD) of P and Ca was evaluated in 96 crossbred barrows (8 replicates with 3 pigs each) fed 4 diets. Diets based on corn (Zea mays), a heat-treated grain mix, and soybean (Glycine max) meal with recommended [positive control (PC)] or reduced [negative control (NC)] P and Ca levels were fed from 25 to 115 kg BW. The PC diets contained 0.61% P and 0.72% Ca from 25 to 45 kg, 0.59% P and 0.66% Ca from 45 to 70 kg, and 0.48% P and 0.51% Ca from 70 kg to final BW. The NC diets were reduced in digestible P by 2.0, 2.0, and 1.1 g/kg and in Ca by 1.4, 1.0, and 0.8 g/kg, respectively, for the 3 phases. Phytase was added at 0, 250, and 500 phytase units (FTU)/kg to the NC diet. Performance was measured at the end of each feeding period and ATTD of P and Ca evaluated for a 3-d collection following a 7-d adaptation at an average BW of 45, 70, and 116 kg. Final BW of NC pigs (111.9 kg) was increased (P < 0.05) by P addition (120.3 kg; PC) and by phytase inclusion at both rates (116.5 and 117.6 kg, respectively). The ADG of NC pigs (781 g) was increased (P < 0.05) by both phytase levels (5.5 and 6.6%); pigs fed 500 FTU/kg achieved similar ADG as PC pigs (833 and 858 g, respectively). The G:F was reduced (P < 0.05) in NC pigs (0.308) compared to pigs fed the PC diet (0.328) or diets with 250 or 500 FTU phytase/kg (0.324 and 0.330, respectively). The ATTD of P was lowest in all periods for pigs fed NC diets (35.5% in starter, 32.2% in grower, and 32.1% in finisher period). Phytase increased (P < 0.05) ATTD of P in all periods at both application rates. Pigs fed 500 FTU/kg diet had a higher (P < 0.05) ATTD of P than pigs fed 250 FTU/kg and an ATTD of P at least similar to pigs fed PC. Similar but less pronounced effects were observed for ATTD of Ca. The phytase added to grower-finisher diets with reduced P and Ca nearly restored performance to the level of pigs fed diets with adequate P and Ca.

Influence of feeding level on apparent total tract digestibility of phosphorus and calcium in pigs fed low-phosphorus diets supplemented with microbial or wheat phytase

Eighteen pigs (initial body weight 11.3 kg) were used in a 5-week digestibility experiment to investigate the effects of supplemental microbial and native wheat phytase on apparent total tract digestibility (ATTD) of phosphorus (P) and calcium (Ca) at different feeding levels (FL) in a 3 × 3 factorial arrangement of treatments. A low-P (4.2 or 1.4 g/kg DM total or digestible P, respectively) corn–soybean meal diet, either containing 0 or 550 U/kg from microbial ( Penicillium) or wheat phytase, respectively, was fed at three FL (1.2-, 2.0- or 2.8-fold the ME maintenance requirement) in three consecutive periods. Pigs were kept in metabolism crates and feces and urine were quantitatively collected. Supplementation of the control diet with microbial phytase increased ( P < 0.001) ATTD of P and Ca by 22.6 and 18.3 percentage units, respectively. Similarly, but to a smaller extent, inclusion of wheat phytase increased ATTD of P ( P < 0.001) and Ca ( P = 0.005) by 7.4 and 4.9 percentage units, respectively. The overall ATTD of P and Ca were positively influenced by the level of feed intake ( P < 0.001). Increasing the FL improved the efficiency of microbial phytase ( P < 0.05) but not of wheat phytase ( P > 0.05) in rendering phytate P digestible. Phytase effects on ATTD of Ca were not affected ( P > 0.05) by an increase in FL.

Calcium, phosphorus, and amino acid digestibility in low-phytate corn, normal corn, and soybean meal by growing pigs1,2

Nine growing barrows were equipped with a T-cannula in the distal ileum and used to determine apparent ileal (AID) and apparent total-tract digestibility (ATTD) coefficients of Ca and P in low-phytate corn, normal corn, soybean meal, and in diets where soybean meal was mixed with low-phytate corn or normal corn. The AID and the standardized ileal digestibility coefficients (SID) of CP and AA also were determined. The animals (initial BW = 29.3 +/- 1 kg) were allotted to a 9 x 9 Latin square with nine diets and nine periods. Three diets contained low-phytate corn, normal corn, and soybean meal as their sole source of CP, AA, Ca, and P, respectively. Three additional diets were identical to these diets except that limestone and monosodium phosphate were added. Two diets contained low-phytate corn or normal corn and soybean meal, limestone, and monosodium phosphate, and the final diet was a N-free diet. The AID and ATTD of Ca were higher (P < 0.05) for low-phytate corn than for normal corn (70.0 and 69.1% vs. 47.4 and 49.6%, respectively). The AID and ATTD for Ca in soybean meal (50.9 and 46.7%, respectively) did not differ from values for normal corn but were lower (P < 0.05) than for low-phytate corn. The AID and ATTD for P from low-phytate corn (56.5 and 54.5%, respectively) were greater (P < 0.05) than from normal corn (28.3 and 28.8%, respectively), whereas soybean meal had intermediate AID and ATTD for P (37.2 and 38.0%, respectively). The AID and ATTD of P increased (P < 0.05) when monosodium phosphate was added to normal corn (44.9 and 49.8%, respectively) and soybean meal (49.6 and 46.2%, respectively), but adding monosodium phosphate to low-phytate corn, did not alter either AID (49.7%) or ATTD (50.7%) of P. No differences between AID and ATTD for Ca or P within the same diet were observed. The AID of Arg, Asp, Gly, Ile, Lys, Phe, Thr, and Val were greater (P < 0.05) in low-phytate corn than in normal corn. The AID of all AA in soybean meal were greater (P < 0.05) than in both types of corn, with the exception of Ala, Cys, Leu, and Met. The SID of Lys, Phe, and Thr were higher (P < 0.05) in low-phytate corn than in normal corn. Because low-phytate corn has a higher digestibility of Ca and P, less inorganic Ca and P need to be supplemented to diets containing low-phytate corn than to those containing normal corn, and P excretion may be decreased when low-phytate corn is used in the diet.

Factors affecting phosphorus and calcium digestibility in diets for growing-finishing pigs.

In two experiments, we investigated various factors that affect the estimation of the apparent total tract digestibility (ATTD) of DM, Ca, and total P in diets for growing-finishing pigs. In Exp. 1, the effects of age, housing, and calculation method (indicator [Cr2O3] vs 10-d total collection) were determined. Eighteen barrows and gilts (40 to 95 kg BW) were housed in six pens, and ATTD was estimated using the indicator method. Twelve barrows were housed in metabolic crates, and ATTD was estimated using both calculation methods. Dietary treatments were 1) a tapioca-soybean-barley-based diet, 2) Diet 1 supplemented with 400 FTU microbial phytase/kg of diet, and 3) a corn-soybean meal-based diet: In Exp. 2, six barrows (95 to 120 kg BW) were fed a phytase-deficient diet to investigate the effects of coprophagy (40 g fresh feces/kg of diet) and movement. Pigs were fed at 2.8 times maintenance requirement (418 kJ ME/BW.75); water supply was 2.5 L/kg of feed. The ATTD increased as BW increased. Phytase enhanced total P ATTD by an average of 18.1 percentage units. The ATTD of DM was higher and the ATTD of Ca and total P (P < .001) were lower in pigs housed in pens than in pigs housed in metabolic crates. Fecal consumption and movement led to numerical increases in Ca (P = .217) and total P (P = .103) ATTD. Estimates of Ca and total P ATTD using pigs in metabolic crates are lower than estimates in practice.