Total Tract Digestibility Of Phosphorus Research Articles

Standardized total tract digestibility of phosphorus in canola meal fed to gestating or lactating sows without or with a multi-enzyme complex

An experiment was conducted to determine coefficients of standardized total tract digestibility (CSTTD) of P in canola meal (CM) fed to gestating and lactating sows without or with a multi-enzyme complex (MC). Eight sows cannulated on day 40 of gestation were assigned at random to the 4 dietary treatments in a replicated 4 × 4 Latin square design. The 4 diets included 2 cornstarch-based diets with 313g/kg solvent-extracted CM as the only source of P, without or with MC, a casein-cornstarch diet to determine ileal endogenous amino acid losses (amino acid digestibility data reported elsewhere), and a P-free diet to determine the endogenous P losses. All diets contained 3g/kg titanium dioxide as an indigestible marker. Gestating sows were fed 3.0kg/day, whereas, during lactation, sows had ad libitum access to diets. Samples were collected over 3 phases; mid-gestation, late-gestation, and lactation. Each phase had 4 experimental periods lasting 8 days. In each period, after 5-day acclimation to the experimental diets, fecal samples were collected by grab sampling via rectal palpation on day 6. Results indicated no differences in total tract digestibility of nutrients between mid-gestation, late-gestation, and lactation. Enzyme supplementation improved (P < 0.05) the apparent total tract digestibility of dry matter and P, and CSTTD of P during lactation. The CSTTD of P in CM was 0.445 (without MC) and 0.504 (with MC) in mid-gestation, 0.455 (without MC) and 0.492 (with MC) in late-gestation, and 0.442 (without MC) and 0.489 (with MC) in lactation. In conclusion, the average CSTTD for P in CM fed to sows was 0.447 and MC significantly improved the CSTTD of P in CM during lactation.

149 Effects of Microbial Phytase on Standardized Total Tract Digestibility of Phosphorus in Feed Phosphates Fed to Growing Pigs

Abstract The objective of this experiment was to determine the effect of increased microbial phytase on total tract digestibility of P in feed phosphates when fed to growing pigs. A source of monocalcium phosphate (MCP), monosodium phosphate (MSP), and magnesium phosphate (MgP) were procured. Three basal diets were formulated to contain 0, 500, and 4,000 units of microbial phytase (FTU) and no addition of feed phosphates. Nine phosphate-containing diets were formulated by adding each of the 3 feed phosphates and 3 levels of phytase. A P-free diet was formulated to determine the basal endogenous P loss. A total of 117 growing barrows (BW = 15.56 kg; SD = 1.68) were divided into 3 blocks of 39 pigs and allotted to the 13 diets for a total of 9 pigs per diet. During the experiment, pigs were housed individually in metabolism crates equipped with a slatted floor, a feeder, and a nipple drinker. Fecal samples were quantitatively collected for 4 days after 5 days of adaptation using the marker-to-marker approach. Fecal samples were dried and ground before analysis. Fecal samples, feed ingredients, feed phosphates, and diet samples were analyzed for P, Ca, and dry matter and the apparent total tract digestibility (ATTD) and standardized total tract digestibility (STTD) were calculated. The ATTD and STTD of P in the 3 feed phosphates were calculated using difference procedure. The statistical model included the level of phytase and the P source as the fixed effects and the random effects of period and replicate within period. Contrast statements were used to test for linear and quadratic effects of increasing phytase in diets and the model included diet as the fixed effect and period and replicate as the random effects. Pig was the experimental unit. Results indicated that the ATTD and STTD of P in all diets increased (P &amp;lt; 0.05) with the inclusion of 500 or 4,000 FTU, but the ATTD and STTD of P in feed phosphates were not affected by the inclusion of phytase (Table 1). This indicates that the increases in ATTD and STTD of P that were observed in the mixed diets when phytase was used were due to the release of P from phytate in corn and soybean meal and not from an increase in digestibility of P in feed phosphates. However, MgP had a lower (P &amp;lt; 0.05) STTD of P than MCP and MSP. In conclusion, microbial phytase does not increase the digestibility of P in MCP, MSP, or MgP, but the digestibility of P in MgP is less than in MCP and MSP.

Impact of dietary analyzed calcium to phosphorus ratios and standardized total tract digestible phosphorus to net energy ratios on growth performance, bone, and carcass characteristics of pigs.

A total of 2,184 pigs (337 × 1,050, PIC; initially 12.4 ± 0.17 kg) were used in a 143-d study to evaluate the effects of feeding varying analyzed calcium to phosphorus ratios (Ca:P) at two standardized total tract digestible (STTD) phosphorus to net energy ratios (STTD P:NE). Pens of pigs (26 pigs per pen) were assigned to 1 of the 6 dietary treatments in a 2 × 3 factorial with main effects of STTD P:NE and Ca:P ratio. Diets consisted of two levels of STTD P:NE; High (1.80, 1.62, 1.43, 1.25, 1.10, and 0.99 g STTD P/Mcal NE from 11 to 22, 22 to 40, 40 to 58, 58 to 81, 81 to 104, and 104 to 129 kg, respectively); or Low (75% of the High levels), and three analyzed Ca:P ratios (0.90:1, 1.30:1, and 1.75:1). There were 14 pens per treatment. Diets were corn-soybean meal-based and contained a constant phytase concentration within each dietary phase with levels decreasing throughout the trial (phases 1 through 3, 500 FTU/kg, assumed release of 0.13% STTD P; phase 4, 400 FTU/kg, assumed release of 0.11% STTD P; phase 5, 290 FTU/kg, assumed release of 0.09% STTD P; and phase 6, 210 FTU/kg, assumed release of 0.07% STTD P). Overall, there was a Ca:P × STTD P:NE interaction (P < 0.05) observed for average daily gain (ADG), feed efficiency (G:F), final body weight (BW), hot carcass weight (HCW), bone mineral density, bone mineral content, and bone-breaking strength. When feeding Low STTD P:NE levels, increasing the analyzed Ca:P ratio decreased (linear, P < 0.001) ADG final BW, HCW, and tended to worsen G:F, bone mineral density, and bone mineral content (linear, P < 0.10). However, when feeding High STTD P:NE levels, increasing the analyzed Ca:P ratio significantly improved bone mineral content and bone mineral density (linear, P < 0.05), and tended to improve ADG and final BW (linear, P < 0.10) and G:F (quadratic P < 0.10). Additionally, increasing the analyzed Ca:P ratio worsened ADG, G:F, and bone mineralization with Low STTD P:NE but had marginal impacts when adequate STTD P:NE was fed.

Effects of vitamin K supplementation on reproductive performance and bone metabolism-related biochemical markers in lactation sows.

This study was conducted to evaluate the effects of vitamin K (VK) supplementation on reproductive performance and bone metabolism-related biochemical markers in sows. Twenty-four Large White×Landrace sows (mean parity 4.04) were randomly assigned to two dietary treatments (NC diet, a basal diet with 0.5 mg/kg of VK3; VK diet, a basal diet with 5 mg/kg of VK3) with twelve replicates per treatment and one sow per replicate according to parity. The experiment started on day 107 of gestation and lasted until day 21 of lactation (weaning). We observed that there were no differences (p>0.05) in average daily feed intake, backfat loss of sows, live piglet number at birth and weaning, average birth weight, average weaning weight, and average daily gain of piglets between two treatments. The apparent total tract digestibility of phosphorus was increased (p<0.05) in VK sows compared with NC sows. The serum bone alkaline phosphatase, osteocalcin, type I procollagen aminoterminal peptide, and type I procollagen carboxyl-terminal peptide on day of farrowing were higher (p<0.05) in VK sows than in NC sows. The serum phosphorus, parathyroid hormone, tartrate-resistant acid phosphatase, and tumor necrosis factor-alpha on day of weaning were lower (p<0.05) in VK sows compared with NC sows. Therefore, the overall results suggested that increasing dietary VK3 (0.5 to 5 mg/kg) during lactation improved the apparent total tract digestibility of phosphorus and serum bone metabolism biochemical markers in sows.

Digestion and utilization of plant-based diets by transgenic pigs secreting β-glucanase, xylanase, and phytase in their salivary glands.

Novel transgenic (TG) pigs co-expressing three microbial enzymes, β-glucanase, xylanase, and phytase, in their salivary glands were previously generated, which exhibited reduced phosphorus and nitrogen emissions and improved growth performances. In the present study, we attempted to explore the age-related change of the TG enzymic activity, the residual activity of the enzymes in the simulated gastrointestinal tract, and the effect of the transgenes on the digestion of nitrogen and phosphorus content in the fiber-rich, plant-based diets. Results showed that all the three enzymes were stably expressed over the growing and finishing periods in the F2 generation TG pigs. In simulated gastric juice, all the three enzymes exhibited excellent gastrointestinal environment adaptability. The apparent total tract digestibility of phosphorus was increased by 69.05% and 499.64%, while fecal phosphate outputs were decreased by 56.66% and 37.32%, in the TG pigs compared with the wild-type littermates fed with low non-starch polysaccharides diets and high fiber diets, respectively. Over half of available phosphorus and water-soluble phosphorus in fecal phosphorus were reduced. We also found the performance of phosphorus, calcium, and nitrogen retention rates were significantly improved, resulting in faster growth performance in TG pigs. The results indicate that TG pigs can effectively digest the high-fiber diets and exhibit good growth performance compared with wild type pigs.

Effects of microbial phytase on standardized total tract digestibility of phosphorus in feed phosphates fed to growing pigs.

An experiment was conducted to test the hypothesis that the apparent total tract digestibility (ATTD) and the standardized total tract digestibility (STTD) of P in feed phosphates are increased by microbial phytase when fed to growing pigs. Monocalcium phosphate (MCP), monosodium phosphate (MSP), and magnesium phosphate (MgP) from volcanic deposits were used in the experiment. Three corn-soybean meal based diets that contained 0, 500, or 4,000 units of microbial phytase (FTU), but no feed phosphates, were formulated. Nine additional diets were formulated by adding each of the three feed phosphates to the three basal diets. A P-free diet was also formulated to estimate the basal endogenous loss of P, and therefore, 13 diets were used in the experiment. A total of 117 growing barrows (initial body weight: 15.56 ± 1.68 kg) were allotted to the 13 diets with 9 pigs per diet. Pigs were housed individually in metabolism crates equipped with a feeder and a nipple drinker. Installation of a screen floor under the slatted floor allowed for collection of feces. Diets were fed for 10 d, with the initial 5 d being a period of adaptation to the diet followed by a collection period of 4 d. During the experiment, pigs were fed equal amounts of feed twice daily at 0800 and 1600 h. Results indicated that the ATTD and STTD of P in all diets increased with the inclusion of 500 or 4,000 FTU, but the ATTD and STTD of P in the feed phosphates were not affected by the inclusion of phytase. This indicates that the increases in ATTD and STTD of P that were observed in the mixed diets when phytase was used were due to the release of P from phytate in corn and soybean meal and not from an increase in digestibility of P in feed phosphates. However, MgP had a lower (P < 0.05) ATTD and STTD of P than MCP and MSP. In conclusion, microbial phytase does not increase the digestibility of P in MCP, MSP, or MGP, but the digestibility of P in MgP is less than in MCP and MSP.

PSXVI-16 Standardized Total Tract Digestibility of Phosphorus in Black Soldier fly Larvae fed to Pigs

Abstract The objective of the present study was to determine standardized total tract digestibility of phosphorus (P) in black soldier fly (BSF; Hermetia illucens) larvae fed to pigs. Test ingredients were fish meal (66.2% crude protein, 9.2% ether extract, and 2.63% P), 3 sources of defatted BSF larva meal (43.1 to 59.2% crude protein, 8.6 to 13.2% ether extract, and 0.91 to 1.06% P), and a source of full-fat BSF larva (34.2% crude protein, 36.0% ether extract, and 0.70% P). Six barrows with an initial mean body weight of 78.1 kg (SD = 1.0) were individually housed in metabolism crates. Six diets were assigned to the 6 pigs in a 6 × 7 Latin square design with 7 periods resulting in 7 replicates for each treatment. Five experimental diets contained fish meal, defatted BSF larva meal, or full-fat BSF larva at 25% as the sole source of P. Additionally, a P-free diet mainly based on corn starch, sucrose, and gelatin was also prepared to estimate the basal endogenous losses of P. After a 4-day adaptation period, feces were collected for 4 days according to the marker-to-marker procedure. Apparent total tract digestibility of P in full-fat BSF larva (61.9%) was greater (P &amp;lt; 0.05) than that in 2 sources of defatted BSF larva meal (34.8% and 31.5%). Standardized total tract digestibility of P in full-fat BSF larva (71.8%) was greater (P &amp;lt; 0.05) than that in fish meal (51.0%) or 2 sources of defatted BSF larva meal (41.0% and 38.9%). The basal endogenous losses of P were estimated to be 189 ± 62 mg per kg dry matter intake. In conclusion, P in defatted BSF larva meal was less digestible compared with full-fat BSF larva.

Microbial phytase reduces basal endogenous loss of calcium in pigs fed diets containing phytate phosphorus at commercial levels.

The objective of this experiment was to test the hypothesis that increasing dietary phytase reduces basal endogenous loss of Ca and increases P balance in pigs. Seventy barrows (initial body weight: 17.66 ± 1.69 kg) were allotted to seven Ca-free diets using a randomized complete block design with two blocks and five pigs per diet in each block. All diets were based on corn, potato protein concentrate, and full-fat rice bran. A positive control (PC) diet was formulated to contain P at the requirement for standardized total tract digestible (STTD) P by 11 to 25 kg pigs. Six negative control (NC) diets were formulated by reducing the provision of digestible P by 0.15% and adding 0, 250, 500, 1,000, 2,000, or 4,000 phytase units/kg diet. Pigs were housed individually in metabolism crates that allowed for total, but separate, collection of urine and feces. Daily feed allowance was 3.0 times the maintenance requirement for metabolizable energy and was divided into two equal meals. Diets were fed for 12 d with the first 5 d considered the adaptation period. Urine collections started on day 6 in the morning and ceased on day 10 in the morning. Fecal markers were also included in the morning meals on day 6 and day 10 and feces were collected according to the marker-to-marker procedure. Results indicated that the apparent total tract digestibility of dry matter was not affected by dietary P or phytase levels. The basal endogenous loss of Ca was not affected by dietary P, but exponentially decreased (P = 0.030) as phytase level increased in the diets. Phosphorus retention (g/d) and standardized total tract digestibility of phosphorus were greater (P < 0.05) in pigs fed the PC diet compared with pigs fed the NC diet with no phytase. The STTD of P exponentially (P < 0.001) increased as phytase level increased in the diets, but because of the lack of Ca, retention of P (% of absorbed) linearly decreased (P = 0.006) as phytase increased. In conclusion, basal endogenous loss of Ca decreased as dietary phytase increased demonstrating that endogenous Ca can be bound to phytate in the intestinal tract of pigs. However, STTD of P increased as phytase level in the diets increased.

Effect of Fiber Fermentation and Protein Digestion Kinetics on Mineral Digestion in Pigs.

Simple SummaryThere is increasing interest in improving nutrient utilization in pigs and poultry and thereby reduce nutrient excretion into the environment. The present review aims to provide an overview on interactions between fermentable substrates (e.g., starch, fiber, and protein) and selected minerals on nutrient digestion and absorption to determine nutritional solutions to maximize animal performance, principally in the grower–finisher phase. Using in vitro models, the site and rate (kinetics) of nutrient digestion or fermentation of a feed ingredient or diet can be estimated. However, for minerals, no standardized methodology to assess in vitro mineral digestion exists. In vivo, the diet total tract digestibility of phosphorus might be underestimated in diets with fermentable ingredients because of increased diet-specific endogenous phosphorus losses and requires further clarification to better calculate the true total tract digestibility of phosphorus in pigs. The quantification of fiber type, composition of fiber fractions within individual raw materials, their influence on digestion kinetics, and effects on digesta pH and nutrient solubility related to fermentation should be considered. In conclusion, applications of nutrient kinetic data should be considered as part of an integrated approach to support nutrient digestion and absorption in the gastrointestinal tract of pigs, thereby helping to reduce nutrient excretion.Nutrient kinetic data and the timing of nutrient release along the gastrointestinal tract (GIT), are not yet widely used in current feed formulations for pigs and poultry. The present review focuses on interactions between fermentable substrates (e.g., starch, fiber, and protein) and selected minerals on nutrient digestion and absorption to determine nutritional solutions to maximize animal performance, principally in the grower–finisher phase, with the aim of minimizing environmental pollution. For phosphorus (P), myo-inositol 1,2,3,4,5,6-hexakis (dihydrogen phosphate) (InsP6), copper (Cu), and zinc (Zn), no standardized methodologies to assess in vitro mineral digestion exist. The stepwise degradation of InsP6 to lower inositol phosphate (InsP) forms in the GIT is rare, and inositol phosphate4 (InsP4) might be the limiting isomer of InsP degradation in diets with exogenous phytase. Furthermore, dietary coefficients of standardized total tract digestibility (CSTTD) of P might be underestimated in diets with fermentable ingredients because of increased diet-specific endogenous P losses (EPL), and further clarification is required to better calculate the coefficients of true total tract digestibility (CTTTD) of P. The quantification of fiber type, composition of fiber fractions, their influence on digestion kinetics, effects on digesta pH, and nutrient solubility related to fermentation should be considered for formulating diets. In conclusion, applications of nutrient kinetic data should be considered to help enhance nutrient digestion and absorption in the GIT, thereby reducing nutrient excretion.

Effects of particle size and phytase supplementation on apparent and standardized total tract digestibility of phosphorus in hybrid rye fed to growing pigs.

An experiment was conducted to investigate the effects of particle size (PS) and levels of phytase supplementation on the apparent (ATTD) and standardized (STTD) total tract digestibility of P in hybrid rye fed to growing pigs. Thirty-six growing barrows (23.6 ± 1.5 kg initial BW) were individually housed in metabolism crates and randomly allotted to one of six dietary treatments to give six replicates per treatment. The six dietary treatments were arranged in a 2 × 3 factorial with main effects of PS and phytase supplementation levels (0, 500, or 2,500 FTU/kg). Hybrid rye was ground using a hammermill mounted with 4.0- and 3.2-mm screens to obtain material with coarse and fine PS, respectively. Pigs were fed experimental diets for 11 d, including 5 d for adaptation and 6 d for total collection of feces. All data were analyzed using the MIXED procedure of SAS with PS, phytase, and their interaction as fixed effects. Orthogonal polynomial contrasts were used to test linear and quadratic effects of phytase level in both coarse and fine hybrid rye diets. The ATTD and STTD of P were greater (P < 0.05) in diets with fine than in those with coarse hybrid rye. Increasing levels of phytase supplementation linearly (P < 0.01) and quadratically (P < 0.01) improved the ATTD and STTD of P in hybrid rye diets. There were no interaction effects between PS and phytase supplementation on the ATTD and STTD of P in hybrid rye diets. In conclusion, PS reduction improved the digestibility of P in hybrid rye, and supplementing increasing levels of phytase improved P digestibility in linear and quadratic manner in growing pigs fed hybrid rye diets.

The Impact of Dietary Analyzed Calcium to Phosphorus Ratios and Standardized Total Tract Digestible Phosphorus to Net Energy Ratios on Growth Performance, Bone, and Carcass Characteristics of Pigs

A total of 2,184 pigs (PIC 337 × 1050; initially 27.3 lb) were used to evaluate the effects of feeding varying analyzed calcium to phosphorus (Ca:P) ratios at two levels of standardized total tract digestible (STTD) P:NE. Pens of pigs (26 pigs per pen) were assigned to 6 dietary treatments in a randomized complete block design with 14 pens per treatment. Diets consisted of two levels of STTD P:NE, including the PIC recommendation (1.8, 1.62, 1.43, 1.25, 1.10, and 0.99 g STTD P/Mcal NE from 25 to 50, 50 to 90, 90 to 130, 130 to 180, 180 to 230, and 230 to 280 lb, respectively); or 75% of the PIC recommendation, and 3 analyzed Ca:P ratios: 0.90:1, 1.30:1, and 1.75:1. Diets were corn-soybean meal-based and contained phytase (Quantum Blue G, AB Vista, Marlborough, Wiltshire, UK); 500 to 210 FTU/kg with release values from 0.13 to 0.07% STTD P. There was a Ca:P × STTD P:NE interaction (P < 0.05) observed for average daily gain (ADG), feed efficiency (F/G), and final body weight (BW). For ADG and final BW, when feeding 75% of PIC STTD P recommendation, increasing the analyzed Ca:P ratio decreased ADG and final BW (linear, P < 0.001). However, when feeding the PIC STTD P recommendation, increasing the analyzed Ca:P ratio tended to improve ADG and final BW (linear, P < 0.10). For F/G, when feeding 75% of the PIC STTD P recommendation, increasing the analyzed Ca:P ratio tended to worsen F/G (linear, P < 0.10), whereas in pigs fed diets that met PIC STTD P recommendations, increasing the analyzed Ca:P ratio tended to improve F/G in a quadratic (P < 0.10) manner. Despite the interactions, pigs fed the PIC STTD P recommendations had increased ADG, final BW, and improved F/G compared to pigs fed 75% of PIC STTD P recommendations (P < 0.001). In summary, pigs fed at PIC STTD P recommendations had improved overall ADG and F/G compared to pigs fed diets at 75% of PIC STTD P recommendations. Additionally, increasing the analyzed Ca:P ratio worsened ADG and F/G when STTD P was below PIC recommendations but had marginal impacts when adequate STTD P was fed.

Standardized total tract digestibility of phosphorus in bakery meal fed to pigs and effects of bakery meal on growth performance of weanling pigs

Two experiments were conducted to test the hypotheses that microbial phytase improves the standardized total tract digestibility (STTD) of phosphorus (P) in bakery meal and that corn may be replaced by bakery meal in diets for weanling pigs without negative effects on growth performance. Two sources of bakery meal were used in experiment 1 and one of these sources was also used in experiment 2. In experiment 1, eighty weanling barrows (initial body weight: 14.25 ± 1.91 kg) were allotted to a randomized complete block design with 10 diets and 8 replicate pigs per diet. Two basal diets based on each source of bakery meal (i.e., bakery meal 1 and bakery meal 2) were formulated without addition of microbial phytase. Eight additional diets were formulated by adding 500, 1000, 1500, or 3000 units of microbial phytase to each of the 2 basal diets. Pigs were housed individually in metabolism crates and feces were collected quantitatively for 4 d after 5 d of adaptation. Results indicated that greater increases in apparent total tract digestibility and STTD of P were observed in bakery meal 1 compared with bakery meal 2 when phytase was added to diets (interaction, quadratic, P < 0.05). In the second experiment, 160 newly weaned pigs (initial body weight: 7.17 ± 0.94 kg) were randomly allotted to 5 treatments with 8 pens per treatment and 4 pigs per pen. A 2-phase feeding program was used with d 1–14 being phase 1 and d 15–35 being phase 2. A control diet, containing primarily corn, soybean meal, and no bakery meal was formulated in each phase. Four additional diets in each phase were formulated by replacing 250, 500, 750, or 1000 g/kg of corn in the control diet with bakery meal. Results indicated that for the overall 5-wk nursery period, increasing concentrations of bakery meal tended (linear, P = 0.064) to reduce average daily gain and reduced (linear, P < 0.01) gain to feed ratio of pigs, whereas blood indicators of energy and protein utilization were not affected. In conclusion, digestible P in bakery meal may be increased by including microbial phytase in the diets, but a full replacement of corn with bakery meal in diets for weanling pigs may reduce growth performance.

Additivity of digestible energy and nutrient concentrations in hatchery byproducts fed to nursery pigs.

ObjectiveThe objective was to test additivity of digestible energy and nutrient concentrations in the hatchery byproduct mixture fed to nursery pigs.MethodsIn the previous studies, energy, phosphorus, calcium, and amino acid digestibility of infertile eggs, unhatched eggs, culled chicks, and a mixture of 3 hatchery byproduct ingredients was determined in nursery pigs (initial body weight = 9.4 to 14.2 kg). An additivity test was conducted using these determined values.ResultsNo difference was observed between determined and predicted metabolizable energy values in the mixture (3,998 and 3,990 kcal/kg as-is basis, respectively). Measured standardized total tract digestible phosphorus in the mixture was less than the predicted value (4.5 vs 5.3 g/kg as-is basis, respectively; p<0.05). Measured standardized total tract digestible calcium in the mixture was greater compared with the predicted value (40.0 vs 31.7 g/kg as-is basis, respectively; p<0.05). Measured standardized ileal digestible tryptophan in the mixture was greater than the predicted value (3.7 vs 3.1 g/kg as-is basis, respectively; p<0.05) whereas other amino acid values were additive.ConclusionEnergy and most of amino acid concentrations in hatchery byproducts are additive in the mixture fed to nursery pigs.

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

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

Standardized total tract digestibility of phosphorus in high-protein sunflower meal fed to growing pigs with or without phytase supplementation

The objective of this research was to determine the coefficient of apparent (CATTD) and standardized total tract digestibility (CSTTD) of phosphorus (P) in high-protein sunflower meal (HP-SFM) fed to growing pigs with or without phytase supplementation. Twenty-four pigs (19.5 ± 1.9 kg) were assigned to 1 of 4 diets to give 6 replicates per diet. The experimental diets consisted of a corn-soybean meal-based diet and a diet containing 300 g/kg of HP-SFM, both of which were fed without or with phytase supplementation at 500 phytase units/kg. The CATTD and CSTTD of P in experimental diets were determined and then the CATTD and CSTTD of P in HP-SFM were calculated using the difference method. Pigs were fed their diets at approximately 2.8 times the maintenance energy requirement. Pigs were housed individually in metabolism crates for 15 days including 10 days for adaptation to experimental diets and 5 days for total collection of feces. Phytase supplementation decreased (P < 0.05) both calcium (Ca; 21.4 vs. 13.4 g/kg) and P (44.4 vs. 32.3 g/kg) concentrations in feces in HP-SFM-containing diets. The addition of dietary phytase to the HP-SFM-containing diets also reduced (P < 0.05) daily fecal Ca output from 3.08 to 1.86 g/day and daily fecal P output from 6.41 to 4.51 g/day. The CATTD of Ca and P and CSTTD of P increased (P < 0.05) with phytase supplementation in both basal and HP-SFM-containing diets. There was a tendency (P = 0.061) for phytase supplementation to increase P utilization in HP-SFM, and the CATTD and CSTTD of P in HP-SFM with phytase supplementation were 0.37 and 0.38, respectively, which were higher than for HP-SFM without phytase supplementation (0.18 and 0.19, respectively).

Effect of high-phytase supplementation in lactation diets on sow and litter performance.

A total of 109 sows (Line 241; DNA, Columbus, NE) were used to evaluate the effect of increasing dietary phytase in lactation diets, already adequate in P, on sow and litter performance. On d 107 of gestation, sows were blocked by body weight and parity and allotted to 1 of 3 dietary treatments of increasing phytase concentration (0, 1,000, or 3,000 FYT/kg; Ronozyme HiPhos GT 2700, DSM Nutritional Products, Inc., Parsippany, NJ). The control diet contained no phytase and was formulated to contain 0.50% standardized total tract digestible phosphorus (STTD P; 0.45% available P) and 0.62% STTD calcium (0.90% total Ca). The phytase diets that contained 1,000 or 3,000 FYT/kg were also formulated to 0.50% STTD P and 0.62% STTD Ca including the release of 0.132% STTD P and 0.096% STTD Ca. Diets were balanced for net energy and fed from d 107 of gestation until weaning (d 18 ± 3). All farrowings were monitored, with farrowing duration starting at the time the first pig was born until the first dispersal of placental tissues with no subsequent pigs born. Litters were cross-fostered within treatment until 48 h postfarrowing to equalize litter size. There were no differences among treatments in sow body weight at d 107 of gestation, 24 h after farrowing, or at weaning. Sow average daily feed intake from farrowing to weaning tended to increase (linear, P = 0.093) as phytase increased. There was no evidence for difference in the number of total born pigs, as well as the percentage of stillborns, mummies, and born alive pigs at the completion of farrowing. Similarly, phytase supplementation did not influence (P > 0.05) wean-to-estrus interval or litter size after cross-fostering among dietary treatments. Although not significant (linear, P = 0.226), farrowing duration decreased as added phytase increased with a decrease of 47 min (12%) for 3,000 FYT compared with the control. There were no differences in pig weight at weaning, but as a result of increased survivability (linear, P = 0.002), litter weaning weight and overall litter weight gain increased (quadratic, P < 0.05) up to 1,000 FYT of added phytase with no further benefit observed in sows fed 3,000 FYT. In conclusion, sow feed intake tended to increase linearly with increasing added phytase. Feeding 1,000 FYT/kg maximized overall litter gain and weaning weight; however, a larger-scale study with more sows is needed to determine the addition of phytase in lactation diets to reduce farrowing duration.

269 Effects of high phytase supplementation in lactation diets on sow and litter performance

Abstract A total of 109 sows (Line 241; DNA, Columbus, NE) were used in a study to evaluate the effect of increasing phytase concentration in lactation diets on sow and litter performance. On d 107 of gestation, sows were blocked by body weight and parity and allotted to 1 of 3 dietary treatments of increasing phytase concentration (0, 1,000, or 3,000 FYT/kg; Ronozyme HiPhos 2700; DSM Nutritional Products, Inc., Parsippany, NJ). The control diet contained no phytase and was formulated to contain 0.50% standardized total tract digestible phosphorus (STTD P; 0.45% available P) and 0.62% STTD calcium (0.90% total Ca). The same STTD P and Ca concentrations were formulated for the phytase diets considering a release of 0.132 STTD P and 0.094 STTD Ca in both diets. Diets were fed from d 107 of gestation until weaning (d 18 ± 2). Litters were cross-fostered within treatment until 48 h post-farrowing to equalize litter size. Linear and quadratic response to phytase concentration was evaluated using the lmer function in R. There was no evidence for difference in sow body weight change, farrowing performance, wean-to-estrus interval, or litter size among dietary treatments. Sow average daily feed intake from farrowing to weaning tended to increase (linear, P=0.093) as phytase increased. Although not significant (linear, P =0.226), farrowing duration decreased as phytase increased. Litter weaning weight increased (quadratic, P=0.039) and overall litter gain increased (quadratic, P=0.047) with 1,000 FYT of phytase. In summary, sow feed intake tended to increase linearly with increasing phytase; however, feeding 1,000 FYT/kg maximized overall litter gain and weaning weight. This small-scale study suggests sow and litter performance benefits due to high inclusions of dietary phytase; however, a commercial trial with more sows is warranted to confirm these results.

Evaluation of a decision support system for precision feeding of gestating sows.

Precision feeding (PF) with the daily mixing of 2 diets with different lysine content (high (H) or low (L)) was previously reported for growing pigs to reduce protein intake and N excretion compared with a conventional feeding (CF) based on a single diet (C). Using a simulation approach based on farm data, the objective of the present paper was to describe and evaluate a decision support system for the PF of gestating sows allowing the daily distribution of a tailored ration to each sow. Two datasets, 1 of 2,511 gestations (farm A) and 1 of 2,528 gestations (farm B), reporting sows’ characteristics at insemination and objectives at farrowing were used as inputs for a Python model. This model, mainly based on InraPorc, calculates the nutrient requirements of each sow over gestation and simulates the impact of PF in comparison to CF. Simulated diets L, H, and C contained 3.0, 6.5, and 4.8 g/kg of standardized ileal digestible lysine (SID Lys) and 2.0, 3.3, and 2.5 g/kg of standardized total tract digestible phosphorus (STTD-P), respectively. The influence of farm, parity, gestation week, and their interactions, on calculated SID Lys and STTD-P requirements was analyzed applying a mixed model. The calculated SID Lys and STTD-P requirements increased markedly in the last third of gestation (P < 0.01) and were higher for primiparous than for multiparous sows, unless after week 14 for STTD-P requirement. The calculated SID AA and mineral requirements were lower for farm B than farm A (respectively, 2.94 vs. 3.08 g/kg for SID Lys and 1.30 vs. 1.35 g/kg for STTD-P, P < 0.01). On average, feed L represented 86% and 92% of the feed projected to be delivered by the PF strategy in farms A and B, respectively. Compared to CF, average calculated dietary SID Lys content was lowered by 27% and 32% with PF, for farms A and B, respectively, while average calculated dietary phosphorus content was lowered by 13% and 16%. The simulated proportions of sows in excess and deficient in SID Lys were reduced with PF. Compared to CF, the PF strategy allowed for a 3.6% reduction in simulated feed cost per sow during gestation, and reduced nitrogen and phosphorus intake (by 11.0% and 13.8%, respectively) and excretion (by 16.7% and 15.4%, respectively). To conclude, these simulations indicate that PF of gestating sow appears to be relevant to meet the amino acid requirement while reducing feed cost, and supplies and excretion of nitrogen and phosphorus.

PSI-11 Standardized total tract digestibility of phosphorus in high-protein sunflower meal fed to growing pigs with or without phytase supplementation

Abstract The objective of this research was to estimate the apparent (ATTD) and standardized (STTD) total tract digestibility of phosphorus (P) in high-protein sunflower meal (HP-SFM) fed to growing pigs with or without phytase supplementation. Twenty-four individually-housed pigs (19.5 ± 1.9 kg) were assigned to 1 of 4 diets in a completely randomized design to give 6 replicates per diet. The experimental diets consisted of a corn-soybean meal-based basal diet and a diet containing 30% of HP-SFM, both of which were fed without or with phytase supplementation at 500 phytase units/kg. Pigs were given their daily feed allowance at 2.8 times the maintenance energy requirement. The experimental period lasted for 15 d including 10 d for adaptation to experimental diets and 5 d for total collection of feces. The STTD of P was calculated by correcting the ATTD of P with the basal endogenous P loss, which was assumed to be 190 mg/kg dry matter intake. Phytase supplementation decreased (P &amp;lt; 0.05) both calcium (Ca; 1.34 vs. 2.14%) and P concentrations in feces (3.23 vs. 4.44%) in HP-SFM including diets. Addition of dietary phytase to the HP-SFM-contained diets also reduced (P &amp;lt; 0.05) daily Ca output from 3.08 to 1.86 g/d and daily P output from 6.41 to 4.51 g/d. The ATTD of Ca and P and STTD of P increased (P &amp;lt; 0.05) by providing phytase in both basal and HP-SFM including diets. The ATTD and STTD of P in HP-SFM were 18.4 and 19.3% for without phytase and 36.5 and 37.5% for with phytase, respectively, and there was a tendency (P = 0.063) for phytase supplementation to increase P utilization in HP-SFM fed to growing pigs. The standardized total tract digestible P content in HP-SFM was calculated at 3.61 g/kg.

PSVII-2 Influence of source and concentration of phosphorus on apparent ileal digestibility and apparent total tract digestibility of phosphorus in growing pigs

Abstract A study was conducted to examine the influence of source and concentration of phosphorus (P) on the apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of P in growing pigs. Six diets were formulated in a 2 × 3 factorial arrangement with soybean meal (SBM) or corn distillers’ dried grain with solubles (DDGS) as sole sources of dietary P, and concentration of P at 2.0, 2.5 or 3.0 g/kg. Eighteen cannulated pigs (initial BW = 40 ± 5 kg) were allotted to triplicate 6 × 3 incomplete Latin square design with 6 diets and 3 periods, which consisted of 5 d adaption, 2 d fecal collection, and 2 d ileal digesta collection. The results indicated that AID of P was not different from ATTD of P in all diets (P = 0.45). The digestibility of P was affected by source of P (P &amp;lt; 0.01), with mean of 33.7% in SBM and 50.3% in DDGS. The AID of P in SBM increased linearly (P &amp;lt; 0.05) with increasing P concentrations; however, there was no effect of increasing P concentrations on AID and ATTD of P in DDGS. Determined by regression analysis, true ileal digestibility of P was 58.3% or 57.6%, and true total tract digestibility of P was 56.0% or 62.6%, for SBM or DDGS respectively. The estimated ileal endogenous P loss was 0.61 or 0.13 g//kg DMI, and total tract endogenous P loss was 0.53 or 0.35 g/kg DMI, for SBM or DDGS respectively. In summary, source and concentration of dietary P affect the digestibility of P in growing pigs but there was no difference between AID and ATTD of P.