Microbial phytase in poultry nutrition

Nutritional and physiological responses to dietary phosphorus levels and phytase in pullets and laying hens

The objective of this study was to determine the effects of dietary available phosphorus (P) levels and dietary phytase added into the very low-P diet on the performance, mineral balance, odor emission, and stress responses in growing pullets and laying hens during 13 to 32 wk of age. One hundred sixty-eight pullets (Hy-Line Brown) were randomly assigned into 1 of 4 dietary treatments with 7 replicates of 6 birds each. Experimental diets were formulated to contain 3 graded P levels at 0.25, 0.35, and 0.45% during 13 to 15 wk (phase 1), 0.25, 0.35, and 0.45% during 16 to 18 wk (phase 2), and 0.20, 0.30, and 0.40% during 19 to 32 wk (phase 3). In addition, dietary phytase (500 FTU/kg matrix values) was added into the very low-P diets (0.20% during 13-15 wk, 0.25% during 16-18 wk, and 0.20% during 19-32 wk) to meet the nutritional adequacy with standard P diets. In all phases, decreasing dietary P levels did not affect (P > 0.05) growth, laying performance, and egg qualities. Decreasing dietary P levels linearly increased the relative duodenal and oviduct weights (P < 0.05), and quadratically increased the relative ovary weight in pullets (P = 0.016). Dietary phytase lowered (P = 0.021) the relative duodenal weight compared with the very low-P diet. Tibia breaking strength and tibia Mg contents in pullets were linearly lowered (P < 0.05) as dietary P levels decreased. Dietary phytase tended to increase (P = 0.091) tibia breaking strength and significantly increased (P = 0.025) tibia Mg content compared with the very low-P diet. Dietary P levels and dietary phytase affected (P < 0.05) ileal crypt depth and ileal villus height: crypt depth ratio in pullets. Decreasing dietary P levels linearly decreased (P < 0.01) crude fat digestibility and P excretion in both pullets and laying hens. Dietary phytase reversed (P < 0.05) the very low-P diet-mediated decrease of crude fat digestibility in pullets and laying hens. Dietary P levels and dietary phytase affected (P < 0.05) odor emission including ammonia in pullets and total volatile fatty acids in laying hens. Finally, lowering dietary P levels increased (P < 0.01) yolk corticosterone concentrations and the increased corticosterone concentration by the very low-P diet was reversed by dietary phytase. Collectively, our study shows that decreasing dietary P levels induced nutritional and physiological responses in pullets and laying hens and these P-mediated negative effects were mitigated by dietary phytase.

Unlocking Phytate with Phytase: A Meta-Analytic View of Meat-Type Chicken Muscle Growth and Bone Mineralization Potential

The inclusion of exogenous phytase in P- and Ca-deficient diets of broilers to address the growing concern about excessive P excretion into the environment over the years has been remarkably documented. However, responses among these studies have been inconsistent because of the several factors affecting P utilization. For this reason, a systematic review with a meta-analysis of results from forty-one studies published from 2000 to February 2024 was evaluated to achieve the following: (1) quantitatively summarize the size of phytase effect on growth performance, bone strength and mineralization in broilers fed diets deficient in P and Ca and (2) estimate and explore the heterogeneity in the effect size of outcomes using subgroup and meta-regression analyses. The quality of the included studies was assessed using the Cochrane Collaboration's SYRCLE risk of bias checklists for animal studies. Applying the random effects models, Hedges' g effect size of supplemented phytase was calculated using the R software (version 4.3.3, Angel Food Cake) to determine the standardized mean difference (SMD) at a 95% confidence interval. Subgroup analysis and meta-regression were used to further explore the effect size heterogeneity (PSMD ≤ 0.05, I2 > 50%, n ≥ 10). The meta-analysis showed that supplemental phytase increases ADFI and BWG and improves FCR at each time point of growth (p < 0.0001). Additionally, phytase supplementation consistently increased tibia ash, P and Ca, and bone strength (p < 0.0001) of broilers fed P- and Ca-deficient diets. The results of the subgroup and meta-regression analyses showed that the age and strain of broiler, dietary P source, and the duration of phytase exposure significantly influence the effect size of phytase on growth and bone parameters. In conclusion, phytase can attenuate the effect of reducing dietary-available phosphorus and calcium and improve ADFI, BWG, and FCR, especially when added to starter diets. It further enhances bone ash, bone mineralization, and the bone-breaking strength of broilers, even though the effects of bone ash and strength can be maximized in the starter phase of growth. However, the effect sizes of phytase were related to the age and strain of the broiler, dietary P source, and the duration of phytase exposure rather than the dosage.

Biochemical characterization of purified phytase produced from Aspergillus awamori AFE1 associated with the gastrointestinal tract of longhorn beetle (Cerambycidae latreille)

The need for industrially and biotechnologically significant enzymes, such as phytase, is expanding daily as a result of the increased use of these enzymes in a variety of operations, including the manufacture of food, animal feed, and poultry feed. This study sought to characterize purified phytase from A. awamori AFE1 isolated from longhorn beetle for its prospect in industrial applications. Ammonium sulfate precipitation, ion-exchange chromatography, and gel-filtration chromatography were used to purify the crude enzyme obtained from submerged fermentation using phytase-producing media, and its physicochemical characteristics were examined. The homogenous 46.8-kDa phytase showed an 8.1-fold purification and 40.7% recovery. At 70 C and pH 7, the optimum phytase activity was noted. At acidic pH 4-6 and alkaline pH 8-10, it likewise demonstrated relative activity of 88-95% and 67-88%, respectively. It showed 67-70% residual activity between 30 and 70 C after 40 min, and 68-94% residual activity between pH 2 and 12 after 2 h. The presence of Hg+, Mg2+, and Al3+ significantly decreased the enzymatic activity, whereas Ca2+ and Cu2+ enhanced it. Ascorbic acid increased the activity of the purified enzyme, whereas ethylenediaminetetraacetic acid (EDTA) and mercaptoethanol inhibited it. The calculated values for Km and Vmax were 55.4 mM and1.99 μmol/min/mL respectively. A. awamori phytase, which was isolated from a new source, showed unique and remarkable qualities that may find use in industrial operations such as feed pelleting and food processing.

Effects of phytase enzyme supplementation on growth performance, intestinal morphology and metabolism in Nile tilapia (Oreochromis niloticus)

Phytase is crucial in enhancing the bioavailability and release of phosphorus and other nutrients bound to phytic acid, making them more bioavailable for animal absorption. This study was carried out to inspect the effect of supplementing low phosphorus (P) diet with di-calcium phosphate (DCP) and liquid phytase enzyme (LP), which contains 1500 FTU/kg, on growth performance, intestinal morphometry, proximate body chemical composition, blood profile, immunity status, liver mitochondrial enzyme activities, the expression response and economic returns of Nile tilapia (Oreochromis niloticus). Three triplicate groups of fish (initial weight 5.405 ± 0.045 g, N = 90) were fed on three different diets for 90 days. The first was a control diet with zero DCP; the second was a control diet supplemented with 0.71% DCP; the third was a control diet supplemented with 0.03% LP. The groups were designated as CG, DCP and LP, respectively. Results showed that LP induced considerable improvements (p < 0.05) in FBW, body weight gain, weight gain rate, specific growth rate, HIS, viscero-somatic index, spleen-somatic index, feed conversion ratio, blood parameters and the histomorphometry assessment of intestinal villi absorptive capacity, compared with the other groups. Also, whole-body protein and lipid contents pointedly (p < 0.05) increased by LP, compared with the DCP group. A positive response (p < 0.05) to the phytase enzyme was noted in complexes I, III and IV of the mitochondrial liver complex enzyme activity. Likewise, the relative gene expression levels of (GHr-1, IGF-1, FAS and LPL) were notably (p < 0.05) upregulated by phytase enzyme, associated with DCP and control groups. Further, phytase recorded the highest total return and profit percentage. It can be concluded that Nile tilapia benefits from using phytase enzyme 1500 FTU/kg at 0.03% without adding DCP in terms of good performance and profits.

Total replacement of soybean meal with alternative plant-based ingredients and a combination of feed additives in broiler diets from 1 day of age during the whole growing period

The capacity of combinations of feed enzymes, natural betaine and a probiotic, combined with alternative plant-based ingredients, to totally replace soybean meal (SBM) in a broiler diet was evaluated. Day-old Ross 308 males (2,574) were assigned to 9 treatments (13 pens/treatment, 22 birds/pen) in a completely randomized design. All diets were pelleted and fed ad libitum in 4 phases: starter, grower, finisher 1, finisher 2 (0-10, 10-21, 21-35, and 35-42 d of age, respectively). Treatments included: 1) control diet containing SBM (SBM control), supplemented with phytase (PhyG), at 2,000, 1,500, 1000 and 1,000 FTU/kg in each phase and xylanase (X) at 750 U/kg, [crude protein (CP): 23.5%, 22.0%, 20.2% and 19.3% in each phase]; 2) to 5), alternative (ALT), SBM-free diets, containing the same CP level as the control ("CP high"), supplemented with PhyG as in the control, protease (P, 800 U/kg) and in 2) xylanase (750 U/kg) (ALT+PhyG+P+X), 3) xylanase-β-glucanase (XB, 1,200 U/kg and 152 U/kg) (Alt+PhyG+P+XB), 4) XB plus betaine (800 g/ton) (ALT+PhyG+P+XB+Bet), and 5) XB plus a probiotic [150,000 colony forming units (CFU)/g] (ALT+PhyG+P+XB+Prob); 6) to 9) as treatments 2) to 5) but with CP reduced by -2.0 to -1.5% points vs. control ('CP low'). Final (d 42) BW and overall (d 0-42) feed conversion ratio (FCR) of birds fed the SBM control exceeded breeder objectives (+3.8% and -1.9%, respectively). Overall FCR was reduced and d 42 BW increased in birds fed "low" vs. "high" CP (P < 0.01). Overall FCR and feed intake were not different in ALT+PhyG+XB+P+Bet and ALT+PhyG+XB+P+Prob vs. the control, whereas final BW was reduced (P < 0.05) in all ALT treatments but close to breeder objectives (98.3%) in ALT+PhyG+XB+P+Prob. Feed costs of this treatment were similar to the control. Total replacement of SBM with alternative plant-based ingredients in a CP-low diet supplemented with hydrolytic enzymes and probiotics can achieve growth performance outcomes close to commercial breeder objectives.

Effects of enzyme supplementation on growth performance, digestibility of phosphorus, femur parameters and fecal microbiota in growing pigs fed different types of diets

A 42-days study was conducted to evaluate the effects of different dietary types (corn-or wheat-soybean meal-based diet) and phytase (Phy) or a multi-carbohydrase and phytase complex (MCPC) supplementation on growth performance, digestibility of phosphorus (P), intestinal transporter gene expression, plasma indexes, bone parameters, and fecal microbiota in growing pigs. Seventy-two barrows (average initial body weight of 24.70 ± 0.09 kg) with a 2 × 3 factorial arrangement of treatments and main effects of diet type (corn-or wheat-soybean meal-based-diets) and enzyme supplementation (without, with Phy or with MCPC). Each group was designed with 6 replicate pens. The MCPC increased (p < 0.05) average daily gain (ADG) and final body weight (BW). A significant interaction (p = 0.01) was observed between diet type and enzyme supplementation on apparent total tract digestibility (ATTD) of P. The ATTD of P was higher (p < 0.05) in wheat soybean meal-based diets compared to corn-soybean meal-based diets. Compared with the corn-soybean meal-based diet, the relative expression of SLC34A2 and VDR genes in the ileum and SLC34A3 in jejunum of growing pigs fed the wheat-soybean meal based diet was lower (p < 0.05). The MCPC significantly reduced (p < 0.05) the relative expression of TRPV5 and CALB1 genes in the ileum and increased the expression of CALB1 in the duodenum compared to control diet. The phytase increased (p < 0.05) the relative expression of SLC34A1 gene in the duodenum in comparison to control diet and MCPC-supplemented diet. The Ca and P contents in plasma from pigs fed corn-soybean meal-based diet were higher (p < 0.05) than those from pigs fed wheat-soybean meal-based diet, and the parathyroid hormone (PTH) and calcitonin (CT) concentrations were lower (p < 0.05) than those fed wheat-soybean meal-based diet. The content of Ca and P in the femur and the bone strength of pigs in the corn-soybean meal group were significantly higher (p < 0.05) than those in the wheat-soybean meal groups. The phytase increased (p < 0.05) the Ca and P content and bone strength of the femur. Additionally, diet type and both enzymes significantly improved fecal microbial diversity and composition. Taken together, diet type and exogenous enzymes supplementation could differently influence the growth performance, utilization of phosphorus, intestinal transporter gene expression, bone mineralization and microbial diversity and composition in growing pigs.

A New Biosynthetic 6-Phytase Added at 500 Phytase Unit/kg Diet Improves Growth Performance, Bone Mineralization, and Nutrient Digestibility and Retention in Weaned Piglets and Growing-Finishing Pigs

Two experiments were performed to evaluate the effect of a biosynthetic 6-phytase added at 500 phytase unit (FTU)/kg diet on growth performance, bone mineralization, and nutrient digestibility and retention in weaned piglets and growing-finishing pigs. Experiments were performed on 90 weaned male and female piglets with an average initial body weight (BW) at 7.7 ± 0.73 kg, 26 days of age) and 300 male and female growing pigs (initial BW: 21.0 ± 3.44 kg) for 43 and 98 days in experiments 1 and 2, respectively. In each experiment, the animals were assigned to one of three treatments according to a randomized complete block design. The treatments consisted of a positive-control (PC) diet formulated to meet nutrient requirements; a negative-control (NC) diet reduced similarly in calcium (Ca) and digestible P by 0.15 and 0.12% points in phases 1 and 2, respectively, in piglets and by 0.14, 0.11, and 0.10% points, respectively, in phases 1, 2, and 3 in growing-finishing pigs, compared with PC diet; and a NC diet supplemented with the new 6-phytase at 500 FTU/kg diet (PHY). The dietary P and Ca depletion reduced (p < 0.05) the final BW (-11.9%; -7.8%,), average daily gain (ADG, -17.8%; -10.1%), average daily feed intake (ADFI, -9.9%; -6.0%), gain-to-feed (G:F) ratio (-8.9%; -4.6%), and apparent total tract digestibility (ATTD) of P (-7.7% points; -6.7% points) in nursery piglets and growing pigs, respectively. It also decreased (p < 0.001) P and Ca retention by 6.1 and 9.4% points, respectively, in nursery pigs and ash, P, and Ca contents in metacarpal bones by 18.4, 18.4, and 16.8%, respectively, in growing pigs. Compared to animals fed the NC diet, phytase supplementation improved (p < 0.001) the final BW (+7.7%; +11.3%), ADG (+12.5%; +15.0%), G:F ratio (+8.4%; +5.8%), ATTD of Ca (+10.8% points; +7.2% points), and ATTD of P (+18.7% points; +16.6% points) in weaned piglets and growing pigs, respectively. In addition, phytase also increased (p < 0.001) P and Ca retention by 6.1 and 9.4% points, respectively, in nursery pigs and ash, P, and Ca contents in metacarpal bones by 17.7, 15.0, and 15.2%, respectively, in growing pigs. The final BW, ADG, G:F ratio, and bone traits in animals fed the NC diet supplemented with phytase were comparable to animals fed the PC diet. This finding indicates the ability of this novel biosynthetic phytase to restore performance and bone mineralization by improving the availability of P and Ca in piglets and growing pigs fed P- and Ca-deficient diets.

Effects of a Novel Consensus Bacterial 6-Phytase Variant on Growth Performance and Bone Ash of Broilers Fed Complex Diets Highly Deficient in Minerals, Digestible Amino Acids and Energy through 42 Days of Age

An experiment was conducted to evaluate the effects of increasing the dose of a novel consensus bacterial 6-phytase variant expressed in Trichoderma reesei (PhyG) in broilers fed complex diets highly deficient in minerals, dig AA, and energy. Diets were a nutrient-adequate control (PC); a nutrient-reduced control (NC) formulated with a reduction in available P (avP) by 0.199%, Ca by 0.21%, crude protein by 0.72-1.03%, dig Lys by 0.064-0.084%, Na by 0.047%, and ME by 87.8 kcal/kg, respectively; and NC supplemented with PhyG at 500, 1000, and 2000 FTU/kg feed. BW was decreased and FCR increased in the NC vs. PC, while the PhyG treatments were similar to the PC. Carcass yield and bone ash were also maintained with PhyG supplementation. Phytase provided economic benefit on a feed cost per kg of weight basis for 1 to 35 d; the cost reductions equated to USD 0.006, 0.016, and 0.02/kg BWG at 500, 1000, and 2000 FTU/kg. In conclusion, this trial demonstrated that supplementation with a novel consensus phytase variant in diets highly deficient in minerals, dig AA, and energy maintained growth performance and provided economic benefit, with production benefits being maximized at inclusion levels of 2000 FTU/kg.

Evaluation of exogenous phytase in high-phytate diets for broiler chickens and pigs

There is a gap in the understanding of the relationship between dietary phytate levels and the relative efficacy of phytase to improve amino acid (AA) digestibility in pigs and chickens. Two experiments were conducted to investigate the effect of exogenous phytase on standardized ileal digestibility (SID) of AA and the apparent ileal digestibility (AID) of P in both standard- (SP) and high-phytate (HP) diets for broilers and swine. There were either 40 cages of Cobb 500 male broilers or 10 crossbred barrows (35 kg) fitted with ileal T-cannulas. Both studies were allotted to five dietary treatments (8 replicates). Treatments consisted of four corn-soybean meal-based diets arranged in a 2 × 2 factorial of standard or high phytate and exogenous phytase at 0 or 1 000 phytase units (FYT)/kg; and one N-free diet. Birds were fed a common starter diet from d 0 to 20 and fed experimental diets from d 20 to 25. Birds were euthanized on d 25 via CO2 asphyxiation, and digesta were collected from the terminal ileum. Pigs were fed for a total of four 7-d periods, where digesta were collected on d 6 and 7 of each period. Diet and digesta samples were analyzed for DM, N, Ti, AA, and P to determine AA and P digestibility. The SID of AA was determined by correcting the AID of AA for the basal endogenous losses estimated using the N-free diet. Main effects of the diet type (standard or HP) and phytase (0 or 1 000 FYT/kg), and the interaction of diet type and phytase were evaluated. For both experiments, the HP diets produced lower SID of AA compared to the SP (P < 0.001). For broilers, there was a phytase effect (P < 0.001) for the SID of all AAs evaluated regardless of the diet type. For pigs, phytase improved (P < 0.05) the SID of Met, Lys, Cys, Glu and Ser and tended to improve (P < 0.10) Arg, Leu, Thr, and Tyr. There were no significant interactions for either experiment. For both experiments, AID of P was lower for the HP diets (P < 0.01), and phytase produced greater AID of P for both diet types (P < 0.01). These data indicate that phytase greatly improves the digestibility of P for broilers and pigs and has the ability to significantly increase the digestibility of amino acids for these animals, regardless of the dietary phytate P.

Basis for the diversity and extent in loss of digestible nutrients created by dietary phytin: Emphasis on fowl and swine

Phytin is the Ca2+-Mg2+-K+ salt of phytic acid that is created and deposited in the aleurone layer and/or germ of grains and legumes. Its high presence in feedstuffs for fowl and swine diets results in it being a universal and significant impediment to optimum performance. Phytin impairs gastrointestinal recovery of a wide array of nutrients, the effect varying with the nutrient concerned. On exposure to low pH during gastric digestion, phytin dissociates into phytic acid and solubilized Ca2+. Even at low gastric pH, phytic acid is negatively charged which forms the basis of its anti-nutritive behavior. Pepsinogen has extensive basic amino acids on its activation peptide that are presented as cations at low pH which are targeted by pepsin for activation. Partially crystalized Ca2+ near the enzyme's active site further stabilizes its newly formed structure. Thus, phytic acid appears to interfere with gastric digestion by several mechanisms; interfering with pepsinogen activation by binding to the polypeptide's basic amino acids; coordinating free Ca2+, destabilizing pepsin; binding some dietary proteins directly, further compromising gastric proteolysis. Upon digesta attaining neutrality in the duodenum, Ca2+ and other cations re-bind with accessible anions, phytic acid being a significant contender. Phytate not only binds free cations but can also strip them from enzymes (e.g. Ca2+, Zn2+) which reduces their structural resistance to autolysis and ability as co-factors (e.g. Zn2+) to increase enzyme activity. Goblet cells initially employ Ca2+ as an electronic shield between mucin layers enabling granule formation and cell storage. After mucin granule release, Ca2+ is progressively displaced by Na+ to free the viscous mucins enabling its translocation. Mucin entangles with the glycocalyx of adjacent enterocytes thereby constructing the unstirred water layer (USWL). Excessive removal of Ca2+ from mucin by phytic acid increases its fluidity facilitating its loss from the USWL with its associated Na+. This partly explains increased mucin and Na+ losses noted with high phytate diets. This review suggests that phytic acid binding of Ca2+ and less so Zn2+ is the basis for the diversity in nutrient losses encountered and that such losses are in proportion to dietary phytate content.

Feeding Value of Lupins, Field Peas, Faba Beans and Chickpeas for Poultry: An Overview

Grain legumes are fair sources of protein, amino acids and energy, and can be used as a replacement for soybean meal in poultry feed formulations as the soybean meal becomes short in supply and costly. However, a concern associated with the use of grain legumes in poultry feeding is the presence of antinutritional factors. The effective processing and utilisation of these grain legumes in poultry feeding are well documented. The current review focuses on four selected grain legumes (lupins [Lupinus albus and Lupinus angustifolius], field peas [Phaseolus vulgaris], faba beans [Vicia faba] and chickpeas [Cicer arietinum]) and their nutrient content, the presence of antinutritional factors, processing methods and feeding value, including updated data based on recent research findings.

Komagataella phaffii as a Platform for Heterologous Expression of Enzymes Used for Industry

In the 1980s, Escherichia coli was the preferred host for heterologous protein expression owing to its capacity for rapid growth in complex media; well-studied genetics; rapid and direct transformation with foreign DNA; and easily scalable fermentation. Despite the relative ease of use of E. coli for achieving the high expression of many recombinant proteins, for some proteins, e.g., membrane proteins or proteins of eukaryotic origin, this approach can be rather ineffective. Another microorganism long-used and popular as an expression system is baker's yeast, Saccharomyces cerevisiae. In spite of a number of obvious advantages of these yeasts as host cells, there are some limitations on their use as expression systems, for example, inefficient secretion, misfolding, hyperglycosylation, and aberrant proteolytic processing of proteins. Over the past decade, nontraditional yeast species have been adapted to the role of alternative hosts for the production of recombinant proteins, e.g., Komagataella phaffii, Yarrowia lipolytica, and Schizosaccharomyces pombe. These yeast species' several physiological characteristics (that are different from those of S. cerevisiae), such as faster growth on cheap carbon sources and higher secretion capacity, make them practical alternative hosts for biotechnological purposes. Currently, the K. phaffii-based expression system is one of the most popular for the production of heterologous proteins. Along with the low secretion of endogenous proteins, K. phaffii efficiently produces and secretes heterologous proteins in high yields, thereby reducing the cost of purifying the latter. This review will discuss practical approaches and technological solutions for the efficient expression of recombinant proteins in K. phaffii, mainly based on the example of enzymes used for the feed industry.

Enhancing the Production Performance and Nutrient Utilization of Laying Hens by Augmenting Energy, Phosphorous and Calcium Deficient Diets with Fungal Phytase (Trichoderma reesei) Supplementation

A ten-week trial was conducted to evaluate the enhancement of production performance and nutrient utilization of laying hens through augmenting energy, phosphorous, and calcium deficient diets with fungal phytase (Trichoderma reesei) supplementation. 720 Hy-line Brown hens aged 28 weeks were randomly divided into 5 groups; each group had 8 replicates of 18 hens. Five experimental diets were prepared and fed to corresponding groups. A positive control (PC) diet contained 3.50% of calcium (Ca), 0.32% of non-phytate phosphorus (NPP), and apparent metabolic energy (AME) of 11.29MJ/kg, while a negative control (NC) diet contained 3.30% of Ca, 0.12% of NPP, and lower AME of 300 kJ/kg. The other three diets were supplemented with 250 FTU/kg phytase (PHY-250), 1000 FTU/kg phytase (PHY-1000), and 2000 FTU/kg phytase (PHY-2000) in addition to a regular NC diet. Results indicated that the positive control (PC) diet group had higher body weight gain, egg weight, and average daily feed intake. However, laying rate, egg mass, and FCR were most improved in the PHY-2000 group, followed by the PHY-1000 and PHY-250 groups (p < 0.05). Improved yolk color was most notable in laying hens fed the diet with PHY-1000 as opposed to the PC and NC groups (p < 0.05), but no overall difference was found among all of the phytase treated groups. The apparent availability of dry matter, energy, phosphorus, and phytate P was significantly higher in the PHY-2000 group than in the PC and NC groups (p < 0.05). Compared to the PC group, nitrogen retention was significantly higher in the PHY-1000 group, while calcium availability was higher in the PHY-250 group. The results suggested that the addition of phytase to diets with low P, Ca, and AME improved laying performance and apparent availability of dietary nutrients. Thus, it was concluded that the laying hen diet could be supplemented with 1000-2000 FTU/kg phytase for improving laying production and nutrient availability and mitigating the negative impact of reduced nutrient density in laying hen diets.

Efficacy and Equivalency of Phytase for Available Phosphorus in Broilers Fed an Available Phosphorus-Deficient Diet

This study was conducted to assess the effectiveness of phytase on the performance, carcass traits, nutrient digestibility, tibia characteristics, and inositol phosphorus (IP) degradation in broiler chickens. Additionally, the available phosphorus (AP) equivalency of phytase in AP-deficient diets was estimated for 35 days after hatching. A total of 336 one-day-old Ross 308 broiler chicks were allocated to one of seven dietary treatments with six replications with eight birds per cage. The dietary treatments were as follows: (1) positive control containing 0.45% AP of the starter and 0.42% AP of the grower diet (PC), (2) 0.10% AP deficiency from the PC (NC-1), (3) 0.15% AP deficiency from the PC (NC-2), (4) 0.20% AP deficiency from the PC (NC-3), (5) NC-3 +phytase (500 FTU/kg; NC-3-500), (6) NC-3 + phytase (1000 FTU/kg; NC-3-1000), and (7) NC-3 + phytase (1500 FTU/kg; NC-3-1500). On d 35, the NC-3 diet exhibited lower tibia weight compared to the other treatments (p < 0.001). The NC-3-1500 group had higher calcium and phosphorus contents in the tibia than the other treatments on d 35 (p < 0.01). Phytase supplementation led to a reduced IP6 concentration and increased IP3 concentrations in different sections of the gastrointestinal tract on d 21 and 35 compared to the control diet (p < 0.05). In conclusion, based on the tibia phosphorus content, this study determined that 500 FTU/kg phytase was equivalent to 0.377% and 0.383% AP in the diet on d 21, and 0.317% and 0.307% AP in the diet on d 35, respectively. Likewise, 1000 FTU/kg was determined to be equivalent to 0.476% and 0.448% AP on d 21, and 0.437% and 0.403% AP on d 35, respectively. Furthermore, 1500 FTU/kg was determined to be equivalent to 0.574% and 0.504% AP on d 21, and 0.557% and 0.500 AP on d 35, respectively.

Determining the phosphorus release curve for Sunphase HT phytase in nursery pig diets

A total of 280 pigs (DNA 241 × 600, initially 10.4 ± 0.24 kg) were used in a 21-d study to determine the available P (aP) release curve for Sunphase HT phytase (Wuhan Sunhy Biology Co., Ltd., Wuhan, P.R. China) when fed diets with a high phytate concentration. On day 21 post-weaning, considered day 0 of the study, pigs were blocked by average pen body weight (BW) and randomly allotted to 1 of 7 dietary treatments with 5 pigs per pen and 8 pens per treatment. Dietary treatments were derived from a single basal diet, and ingredients including phytase, monocalcium P, limestone, and sand were added to create the treatment diets. Treatments included three diets with increasing (0.11%, 0.19%, and 0.27%) aP from monocalcium P, or four diets with increasing phytase (250, 500, 1,000, or 2,000 phytase unit (FTU)/kg) added to the diet formulated to 0.11% aP. All diets were corn-soybean meal-canola meal-based and were formulated to contain 1.24% SID Lys, a 1.10:1 total calcium-to-phosphorus ratio, and a calculated 0.32% phytate P. Prior to the beginning of the study, all pigs were fed a diet containing 0.11% aP from days 18 to 21 post-weaning. At the conclusion of the study, 1 pig, closest to the mean weight of each pen, was euthanized, and the right fibula, 10th rib, and metacarpal were collected to determine bone ash and density. After cleaning, bones were submerged in ultra-purified water under a vacuum for 4 h and then weighed to calculate the density (Archimedes principle). For bone ash, bones were processed using the non-defatted method. From days 0 to 21, increasing aP from monocalcium P increased (linear, P ≤ 0.014) average daily gain (ADG), gain-to-feed (G:F), and final BW. Pigs fed increasing phytase had increased (linear, P ≤ 0.045) ADG, final BW, and plasma inositol concentration as well as improved (quadratic, P = 0.023) G:F. For bone characteristics, pigs fed increasing aP from inorganic P had a linear improvement (P ≤ 0.019) in fibula bone ash weight and percentage bone ash, rib bone ash weight and bone density, and all metacarpal bone properties, with a quadratic response (P ≤ 0.030) for fibula bone density and rib percentage ash. Additionally, pigs fed increasing phytase had increased (P < 0.05) bone ash weight, percentage bone ash, and bone density in either a linear or quadratic fashion depending on the bone analyzed. The available P release curve generated for Sunphase HT phytase for percentage bone ash combining values from the right fibula, 10th rib, and metacarpal is aP release, % = (0.360 × FTU) ÷ (2,330.250 + FTU).

Application of enzyme matrix values for energy and nutrients to a wheat-corn-soybean meal-based broiler diet supplemented with a novel phytase, with or without a xylanase-β-glucanase, achieved a production benefit over a nutritionally adequate unsupplemented diet

The effect of applying an energy and nutrient matrix to a wheat-corn-soybean meal-based diet supplemented with a novel consensus bacterial 6-phytase variant (PhyG) and xylanase-β-glucanase on growth performance, bone mineralization, carcass weights, feed costs, and carbon footprint was evaluated. A randomized complete block design (3,300 Ross 308 mixed-sex birds; 60 pens, 12 pens per treatment) tested 5 treatments: 1) a positive control diet (PC), containing 0.92, 0.84, 0.71% Ca and 0.43, 0.38, 0.30% digestible P during 1 to 10, 11 to 21, and 22 to 32 d of age, respectively; 2) a negative control reduced in Ca, digestible P, digestible AA, ME, and Na by phase based on the PhyG dosing regimen (NC1); 3) NC1 supplemented with PhyG at 2,000, 1,500, and 1,000 FTU/kg by phase (NC1+PhyG); 4) as NC1 but additionally reduced in ME (NC2); and 5) NC2 supplemented with PhyG as in 3) plus 1,220 U/kg of xylanase and 152 U/kg of β-glucanase (NC2+PhyG+XB). Final (d 32) BW, overall (0-32 d of age) ADFI, FCR, d 10 and 32 tibia ash and carcass part weights were reduced or impaired (P < 0.05) in NC1 and NC2 vs. PC (d 32 BW -477 g/bird (23.4%) and -422 g/bird (20.7%), respectively). Growth performance (all measures, all phases) was improved and tibia ash (at 10 and 32 d of age), total carcass thigh, breast and leg weights were increased (P < 0.05) in NC1+PhyG vs. NC1, and NC2+PhyG+XB vs. NC2. Overall growth performance outcomes in NC1+PhyG and NC2+PhyG+XB were not different (P > 0.05) from the PC. Total feed cost and carbon footprint per kilogram BW gain (BWG) were reduced (P < 0.05) vs. PC in NC2+PhyG+XB [-0.052 € and -376 g CO2 eq./kg BWG, respectively] and NC1+PhyG [-0.038 € and -260 g CO2 eq./kg BWG, respectively]. The results validated the nutrient matrices in the test diets and highlighted a potential feed cost and environmental sustainability benefit which was greatest when the enzymes were applied in combination.

Approaches to determine the efficiency of novel 3-phytase from Klebsiella pneumoniae and commercial phytase in broilers from 1 to 14 d of age

This study aimed to evaluate the effects of a laboratory 3-phytase (the expression of the phyK gene, Lab-Phy) and a commercial 6-phytase (Quantum Blue 40 P, Com-Phy) alone and in combination (corn-soy-based diets) in broilers. A total of 400, day-old Ross 308 male broilers were randomly assigned to 5 treatments with 10 replicate cages (8 chicks/cage) for a 14-day trial. Experimental treatments included the positive control (0.95% Ca and 0.48% nonphytate phosphorus (nPP), PC), negative control (0.90% Ca and 0.22% nPP, NC), and NC which was supplemented with Lab-Phy 250 FTU/kg and Com-Phy 250 FTU/kg alone or in combination of Lab-Phy 125 FTU/kg and Com-Phy 125 FTU/kg. The inclusion of Lab-Phy in the NC diet significantly improved the P and Ca content in the tibia compared to the NC group. Moreover, the inclusion of Com-Phy alone and in combination with Lab-Phy in the NC diet significantly increased the P and Ca content in the tibia compared to the Lab-Phy. The mRNA expression of NaPi-IIb was upregulated in the duodenum by the reduction of nPP and downregulated by the inclusion of any phytase, whereas other nutrient transporters were not influenced by the reduction of nPP or the addition of phytase in the small intestine mucosa. Broilers receiving the NC diet obtained the lowest body weight (BW) and body weight gain (BWG) at 8 to 14 and 1 to 14 d of age. The NC group showed the lowest villi height and surface area, Newcastle disease (ND) antibody titer, and digestibility of nutrients compared to the PC group at 14 d of age. Supplementing the NC diet with the Lab-Phy and Com-Phy individually, or in combination tended to improve BW, BWG, tibia characteristics, villi characteristics, ND, and retained CP and P, and apparent ileal digestibility of CP, P, methionine, and threonine. The present research indicated that the studied traits by the combination of phytases were slightly better than the average of the 2 individually, suggesting there might be some value in combining the laboratory and commercial phytases.

Tetracalcium Phosphate Biocement Hardened with a Mixture of Phytic Acid-Phytase in the Healing Process of Osteochondral Defects in Sheep

Hyaline articular cartilage has unique physiological, biological, and biomechanical properties with very limited self-healing ability, which makes the process of cartilage regeneration extremely difficult. Therefore, research is currently focused on finding new and potentially better treatment options. The main objective of this in vivo study was to evaluate a novel biocement CX consisting of tetracalcium phosphate-monetit biocement hardened with a phytic acid-phytase mixture for the regeneration of osteochondral defects in sheep. The results were compared with tetracalcium phosphate-monetit biocement with classic fast-setting cement systems and untreated defects. After 6 months, the animals were sacrificed, and the samples were evaluated using macroscopic and histologic methods as well as X-ray, CT, and MR-imaging techniques. In contrast to the formation of fibrous or fibrocartilaginous tissue on the untreated side, treatment with biocements resulted in the formation of tissue with a dominant hyaline cartilage structure, although fine fibres were present (p < 0.001). There were no signs of pathomorphological changes or inflammation. Continuous formation of subchondral bone and hyaline cartilage layers was present even though residual biocement was observed in the trabecular bone. We consider biocement CX to be highly biocompatible and suitable for the treatment of osteochondral defects.

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

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

Dietary exogenous phytase improve egg quality, reproductive hormones, and prolongs the lifetime of the aging Hy-Line brown laying hens fed nonphytate phosphorus

The study examined how adding phytase to nonphytate phosphorus (NPP) diets affected performance, egg quality, reproductive hormones, and plasma biochemical indices in 73- to 80-wk-old laying hens. Six treatments with 5 replicates of 18 Hy-Line brown laying hens each were randomly assigned. Three isonitrogenous, isocaloric diets containing consistent calcium levels (3.8%) were formulated to contain 0.20, 0.25, and 0.30% NPP, treated with or without phytase supplementation (1,000 FYT per kg feed, Ronozyme HiPhos-L, Aspergillus oryzae 6-phytase). The results showed that the addition of phytase to the diet containing 0.20, 0.25, and 0.30% NPP increased egg production by 1.50, 1.64, and 0.97%, respectively, and improved eggshell thickness. Also, use of phytase in the diet contain 0.25, and 0.30% NPP increased the plasma concentration of albumin (ALB), high-density lipoprotein (HDL), phosphorus (P), and plasma follicle-stimulating hormone (FSH), plasma calcium (Ca), estradiol-17β (E2β), and luteinizing hormone (LH). In contrast, the egg weight, feed intake, egg mass, feed conversion ratio, albumen height, Haugh unit, yolk, and shell color were unaffected. It can be advisable to use phytase supplementation in an elderly laying hen's diet contain 0.25, and 0.30% NPP to improve shell quality and positively impact reproductive hormones leading to the persistence of egg production.

Enhancing micronutrient absorption through simultaneous fortification and phytic acid degradation

Phytic acid (PA), an endogenous antinutrient in cereals and legumes, hinders mineral absorption by forming less bioavailable, stable PA-mineral complexes. For individual micronutrients, the PA-to-mineral molar ratio below the critical level ensures better bioavailability and is achieved by adding minerals or removing PA from cereals and pulses. Although several PA reduction and fortification strategies are available, the inability to completely eradicate or degrade PA using available techniques always subdues fortification's impact by hindering fortified micronutrient absorption. The bioavailability of micronutrients could be increased through simultaneous PA degradation and fortification. Following primary PA reduction of the raw material, the fortification step should also incorporate additional essential control stages to further PA inactivation, improving micronutrient absorption. In this review, the chemistry of PA interaction with metal ions, associated controlling parameters, and its impact on PA reduction during fortification is also evaluated, and further suggestions were made for the fortification's success.

Effect of replacing dicalcium phosphate with mono-dicalcium phosphate to supplement phosphorus on laying performance, phosphorus-calcium metabolism and bone metabolism of aged laying hens

The objective of this study was to evaluate the effect of replacing dicalcium phosphate (DCP) with mono-dicalcium phosphate (MDCP) to formulate low-phosphorus (P) diets on laying performance, egg quality, phosphorus-calcium metabolism, and bone metabolism of 69-78-week-old aged laying hens. Hy-Line Brown laying hens (n = 1,350, 69 weeks old) were randomly assigned to six treatments, each with five replicates of 45 hens. A corn-soybean meal-based diet was formulated to contain 0.12% non-phytate phosphorus (NPP), 3.81% calcium (Ca), and 1,470 FTU/kg phytase. The control group (CON) was supplemented with DCP inorganic phosphorus (Pi) at the NPP level of 0.20% (dietary NPP levels of 0.32%). Test groups (T1-T5) were supplemented with MDCP Pi at NPP levels of 0.07%, 0.11%, 0.15%, 0.18, and 0.20% (dietary NPP levels of 0.19, 0.23, 0.27, 0.30, and 0.32%, respectively). Calcium carbonate levels were adjusted to ensure all experimental diets contained the same Ca levels (3.81%). The feeding trial lasted 10 weeks, with hens increasing in age from 69 to 78 weeks. When supplemented with 1,470 FTU/kg phytase, extra DCP Pi or MDCP Pi did not affect (p > 0.05) laying performance (day laying rate, average egg weight, feed intake, feed-to-egg mass ratio, broken egg rate), egg quality (eggshell strength, albumen height, haugh units), or serum P, Ca, copper (Cu), iron (Fe), zinc (Zn), and manganese (Mn) levels. However, when laying hens were fed MDCP Pi (NPP levels of 0.07 to 0.20%), yolk color improved (p = 0.0148). The tibia breaking strength was significantly higher (p < 0.05) in the 0.18 and 0.20% NPP MDCP Pi groups than in the 0.20% NPP DCP Pi group. The breaking strength, Ca content, and P content of tibia in 0.11% and 0.15% NPP MDCP Pi hens were not significantly (p > 0.05) different from those in 0.20% NPP DCP Pi hens. Hens fed 0.07% NPP MDCP Pi had higher (p < 0.01) serum levels of osteoprotegerin (OPG), type-I collagen c-telopeptide (CTX-I), and tartrate-resistant acid phosphatase 5b (TRACP-5b) than those in all other groups. Serum levels of TRACP-5b and CTX-I in the 0.11% and 0.15% NPP MDCP Pi group were significantly lower than those in 0.18 and 0.20% NPP MDCP Pi groups and the 0.20% NPP DCP Pi group (p < 0.0001). Hens fed 0.07% and 0.11% NPP MDCP Pi had higher (p < 0.05) serum levels of parathyroid hormone (PTH) than those in all other groups. No differences were detected in serum calcitonin (CT), 1,25-dihydroxy-vitamin D3 (1,25-(OH)2D3), bone alkaline phosphatase (BAP), osteocalcin(OCN), and osteopontin (OPN) among all groups (p > 0.05). The expression of P transporters type IIa Na/Pi cotransporter (NaPi-IIa) in 0.11% and 0.15% NPP MDCP Pi hens were higher than those in 0.20% NPP MDCP Pi group and 0.20% NPP DCP Pi group (p < 0.05). The results indicated that both renal P reabsorption and bone resorption were involved in adapting to a low-P diet. In summary, when MDCP was used instead of DCP to supplement P, NPP levels could be reduced to 0.11% (dietary NPP level of 0.23%) without negative effects on laying performance and skeletal health of aged hens. In addition, MDCP was more beneficial than DCP for tibia quality. The results of the current study would provide references for the application of MDCP in low-P diets of aged laying hens.

Effect of Bacterial Phytase on Growth Performance, Nutrient Utilization, and Bone Mineralization in Broilers Fed Pelleted Diets

The influence of a bacterial 6-phytase on growth performance, coefficient of apparent ileal digestibility (CAID) of nutrients, blood parameters, and bone mineralization in broilers was evaluated. A total of 630 one-day-old male broilers were allocated to 7 dietary treatments, including positive control (PC) diet containing dicalcium phosphate, the PC marginally reduced in available P (avP) by 0.1% and calcium (Ca) by 0.2% vs. PC (NC1) or moderately reduced by 0.15 and 0.3% vs. PC (NC2), respectively, and four further diets comprising the NC1 and NC2 supplemented with 500 or 1000 FTU/kg of phytase in starter and finisher phases. A constant Ca to avP ratio was maintained across all diets. The body weight gain (BWG) and feed per unit gain (FCR) of birds fed NC1 and NC2 diets supplemented with phytase (500 and 1000 U/kg) was equivalent to that of birds fed the PC diet at 35 days. Phytase supplementation in the NC1 diet linearly increased the CAID of nitrogen (N) (p < 0.01), phosphorus (P) (p < 0.01), and Ca (p < 0.05). Additionally, phytase reduced (p < 0.01) excreta P concentration by approximately 27%, improved (p < 0.001) toe ash, and tended to increase tibia ash (p = 0.08), comparable with the PC. In conclusion, the addition of bacterial 6-phytase dosed in the range of 500-1000 FTU/kg was effective in replacing 1.5 g/kg avP and 3 g/kg Ca in broilers fed pelleted diets, using bone quality, BWG, and FCR as outcome measures.

Effects of Low-Phosphorus Diets Supplemented with Phytase on the Production Performance, Phosphorus-Calcium Metabolism, and Bone Metabolism of Aged Hy-Line Brown Laying Hens

This study was conducted to evaluate the effects of phytase supplementation in low-phosphorus diets on the production performance, phosphorus–calcium metabolism, and bone metabolism in laying hens from 69 to 78 weeks of age. Hy-Line Brown laying hens (n = 1350) were assigned randomly to six treatments with five replicates of 45 birds. A corn–soybean meal-based diet with no inorganic phosphates was formulated to contain 0.12% non-phytate phosphorus (NPP) and 1470 FTU/kg phytase (Released phytate phosphorus content ≥ 0.1%). Inorganic phosphorus (dicalcium phosphate) was supplemented into the basal diet to construct five test diets (level of NPP supplementation = 0.10%, 0.15%, 0.20%, 0.25%, and 0.30%). The level of calcium carbonate was adjusted to ensure that all six experimental diets contained the same calcium percentage (3.81%). The feeding trial lasted 10 weeks (hens from 69 to 78 weeks of age). Upon supplementation with phytase (1470 FTU/kg), supplemental inorganic phosphates (dicalcium phosphate) had no significant effects (p > 0.05) on the production performance or egg quality. Significant differences in serum levels of calcium, phosphorus, copper, iron, zinc, or manganese were not detected across treatments (p > 0.05). Hens fed NPP (0.15%, 0.20%, 0.25%, and 0.30%) had higher levels (p < 0.0001) of tibial ash, calcium, and phosphorus than those not fed inorganic phosphates. The tibial breaking strength of the group without inorganic phosphates was significantly lower than that of the other groups (p < 0.01). Dietary supplementation with inorganic phosphates had no effect (p > 0.05) on serum levels of calcitonin (CT) and 1,25-dihydroxy-vitamin D3 (1,25-(OH)2D3). Hens that did not receive supplementation with inorganic phosphates had higher serum levels of parathyroid hormone (PTH), osteoprotegerin (OPG), type-I collagen c-telopeptide (CTX-I), and tartrate-resistant acid phosphatase 5b (TRACP-5b) compared with those in the other groups (p < 0.01). Serum levels of CTX-I and TRACP-5b were significantly lower in the NPP-supplementation groups of 0.25% and 0.30% than in the 0.10% NPP-supplementation group (p < 0.01). Dietary supplementation with inorganic phosphates had no effect (p > 0.05) on serum levels of bone-alkaline phosphatase (BAP), osteocalcin (OCN), or osteopontin (OPN). Hens not fed inorganic phosphate had the highest renal expression of phosphorus transporter type IIa Na/Pi cotransporter (NaPi-Ⅱa). Renal expression of NaPi-Ⅱa was increased significantly in NPP-supplementation groups of 0.10–0.20% compared with that in NPP-supplementation groups of 0.25% and 0.30% (p < 0.0001). The results indicated that a reduction in NPP supplementation to 0.15% (dietary NPP level = 0.27%) with phytase inclusion did not have an adverse effect on the production performance or bone health of laying hens from 69 to 78 weeks of age, which might be attributed to renal phosphorus reabsorption and bone resorption. These findings could support the application of low-phosphorus diets in the poultry industry.

Effect of phytase and xylanase enzymes on growth performance and Mucin2 gene expression in broiler chickens

BACKGROUND

Development of exogenous enzymes is one of the most important discoveries in animal nutrition. The supplementation of exogenous enzymes in broiler diets allows for supplying nutrient deficiencies and to decrease endogenous losses.

OBJECTIVES

The effects of phytase (Hostazym and Phyzyme) and xylanase (Ronozyme) enzymes were investigated on growth performance and Mucin2 gene expression in broilers.

METHODS

A completely randomized design was applied, including 7 treatments, 4 replicates and 25 birds per replicates. A total of 700 male Ross (308) broiler chickens were fed with similar diets supplemented by Hostazym and Phyzyme (500 and 1000 FTU/kg) and Ronozyme (100 and 200 EXU/kg). Weight gain (WG), feed intake (FI) and feed conversion ratio (FCR) were determined for three phases and entire rearing period. On 42 days of age, four birds per replicate were slaughtered. Total RNA was extracted from jejunum samples, and Mucin2 gene expression was measured by real-time PCR.

RESULTS

Phytase and xylanase enzymes had a significant effect (p < 0.05) on traits (WG and FCR) in grower and finisher phases and whole rearing period, but FI was not affected by enzymes (p > 0.05). Carcass (74.13 g) and breast (27.76 g) weights by Hostazym (1000 FTU/kg) were higher than other treatments (p < 0.05). Weight of liver, bursa and spleen were significantly influenced by enzymes (p < 0.05). Likewise, bursa and spleen weights in Hostazym (1000 FTU/kg feed) and Ronozyme (200 EXU/kg feed) were significantly higher than other treatments (p < 0.05). Mucin2 gene expression was affected by enzymes in whole treatments. The lowest amount of Mucin2 gene expression belonged to Ronozyme (200 and 100 EXU/kg), and the highest was belonging to Hostazym (1000 FTU/kg).

CONCLUSIONS

Phytase enzymes have higher effect on broiler performance and Mucin2 gene expression compared to xylanase. High doses of Hostazym (1000 FTU/kg feed) could be supplemented in broiler chicken diets to improve optimum growth and feed efficiency.

Influence of Dietary Phytase Inclusion Rates on Yolk Inositol Concentration, Hatchability, Chick Quality, and Early Growth Performance

The aim of this study was to determine the influence of dietary phytase in breeder hens on yolk nutrients, hatchability, chick quality, and growth rate of their progeny, and their subsequent performance to 42 d post-hatch when fed diets with the same phytase concentrations. Breeder hens (n = 216) were divided into 3 groups receiving nutrient-adequate diets with reduced calcium (Ca) and phosphorus (P) (by 0.16% and 0.15%, respectively), supplemented with either 500, 1500, or 4500 FTU/kg phytase from 27 to 50 weeks of age. Eggs were collected at 38 weeks of age and incubated. On the day of hatch, the chick quality and hatchability were determined, and 18 chicks/group were euthanized for yolk sac collection and the determination of inositol and glycerol concentrations. The remaining chicks were divided into three groups, receiving different diets with reduced Ca and P (by 0.16% and 0.15%, respectively), supplemented with 0, 500, or 1500 FTU/kg phytase to 42 d post-hatch. Increasing the phytase concentration in the breeder hen diet linearly (p < 0.05) increased the number of early embryo deaths and decreased the number of late deaths and pips. The inositol concentration in the yolk sac at day of hatch increased (quadratic; p < 0.05) as the phytase dose increased in the breeder hen diet. The breeder hen diet (p < 0.05) influenced the body weight (BW), feed intake (FI), and feed conversion ratio (FCR) up to 21 days of age. The supplementation of breeder hen diets with 1500 FTU/kg phytase increased the concentration of sodium (Na), magnesium (Mg), potassium (K), manganese (Mn), and zinc (Zn) in the yolk sac. The inclusion of phytase doses up to 4500 FTU/kg appeared to influence embryo mortality, chick feed intake, and BW gain to 21 days and the FCR throughout the entire production phase.

Dietary muramidase increases ileal amino acid digestibility of wheat and corn-based broiler diets without affecting endogenous amino acid losses

The objective of these studies was to evaluate the impact of dietary muramidase (MUR) on endogenous amino acids (AA) losses and digestibility of nutrients in wheat and corn-based broiler diets. In experiment 1, the effect of dietary MUR on the flow of endogenous AA (EAA) at the jejunum and terminal ileum of broilers were assessed using either the nitrogen (N) free diet method (NFD) or the highly digestible protein diet method (HDP; 100 g casein/kg diet). Sialic acid and muramic acid concentrations were measured in the jejunal content. In experiment 2, a 2x2x2 factorial arrangement of treatments with 2 base grains (wheat or corn), with low or high metabolizable energy (ME) levels, and without or with MUR supplementation was implemented. All diets contained phytase, xylanase, and cellulase. Apparent ileal digestibility (AID) of dry matter (DM), protein (CP), amino acids (AA), crude fat, and energy, as well as the apparent total tract metabolizability (ATTM) of DM, CP, and gross energy (GE) were determined. The standardized ileal digestibility (SID) of AA was obtained by correcting AID values for basal ileal EAA obtained from chicks fed with NFD or HDP in experiment 1, jejunal EAA flow of all AA was higher (P < 0.001) compared to the ileum, but this effect was method dependent. Jejunal, but not ileal, EAA flow measured with HDP was higher compared to NFD, as well as sialic acid (P < 0.001) and muramic acid (P < 0.004) concentrations. Muramidase inclusion had no effect on basal EAA flow, independently of the segment and the method used. In experiment 2, dietary MUR supplementation increased the AID of CP (P < 0.05), all AA, and tended (P = 0.07) to increase the AID of GE, independently of the cereal type used. However, ATTM of DM and GE, but not CP, increased with MUR inclusion compared with the control treatments, especially in wheat and low ME diets (P < 0.05). In conclusion, MUR supplementation improved AID of CP and AA without affecting EAA losses and increases energy utilization.

The Contribution of Phytate-Degrading Enzymes to Chicken-Meat Production

The contribution that exogenous phytases have made towards sustainable chicken-meat production over the past two decades has been unequivocally immense. Initially, their acceptance by the global industry was negligible, but today, exogenous phytases are routine additions to broiler diets, very often at elevated inclusion levels. The genesis of this remarkable development is based on the capacity of phytases to enhance phosphorus (P) utilization, thereby reducing P excretion. This was amplified by an expanding appreciation of the powerful anti-nutritive properties of the substrate, phytate (myo-inositol hexaphosphate; IP₆), which is invariably present in all plant-sourced feedstuffs and practical broiler diets. The surprisingly broad spectra of anti-nutritive properties harbored by dietary phytate are counteracted by exogenous phytases via the hydrolysis of phytate and the positive consequences of phytate degradation. Phytases enhance the utilization of minerals, including phosphorus, sodium, and calcium, the protein digestion, and the intestinal uptakes of amino acids and glucose to varying extents. The liberation of phytate-bound phosphorus (P) by phytase is fundamental; however, the impacts of phytase on protein digestion, the intestinal uptakes of amino acids, and the apparent amino acid digestibility coefficients are intriguing and important. Numerous factors are involved, but it appears that phytases have positive impacts on the initiation of protein digestion by pepsin. This extends to promoting the intestinal uptakes of amino acids stemming from the enhanced uptakes of monomeric amino acids via Na⁺-dependent transporters and, arguably more importantly, from the enhanced uptakes of oligopeptides via PepT-1, which is functionally dependent on the Na⁺/H⁺ exchanger, NHE. Our comprehension of the phytate-phytase axis in poultry nutrition has expanded over the past 30 years; this has promoted the extraordinary surge in acceptance of exogenous phytases, coupled with the development of more efficacious preparations in combination with the deflating inclusion costs for exogenous phytases. The purpose of this paper is to review the progress that has been made with phytate-degrading enzymes since their introduction in 1991 and the underlying mechanisms driving their positive contribution to chicken-meat production now and into the future.

Effect of phytase and limestone particle size on mineral digestibility, performance, eggshell quality and bone mineralization in laying hens

The effect of microbial phytase and limestone particle size (LmPS) was assessed in Lohmann Tradition laying hens from 31 to 35 wk of age. Seventy-two hens were used in a completely randomized trial according to a 2 × 2 factorial arrangement with 2 levels of phytase/basal available P (aP); 0 FTU/kg with 0.30% aP or 300 FTU/kg with 0.15% aP, and 2 limestone particle sizes; fine particles (FL, <0.5 mm) or a mix (MIX) of 75% coarse limestone (CL, 2-4 mm) and 25% FL. Diets contained equivalent levels of Ca (3.5%), phytic P (PP; 0.18%), and aP (0.30%) considering the P equivalency of phytase. Thus, dietary treatments were FL0 and MIX0 without phytase, and FL300 and MIX300 with 300 FTU/kg phytase. Performance were recorded daily and eggshell quality (eggshell weight proportion, weight, thickness, and breaking strength) was measured weekly. At the end of the trial, bone parameters (tibia breaking strength, elasticity, and ash) and the apparent precaecal digestibility (APCD) of P and Ca were determined. No differences were observed between treatments in feed intake, FCR and bone parameters. Addition of MIX increased the eggshell proportion, weight and thickness in groups receiving no phytase (+6.5, +6.9, and +4.5%, respectively) while no effect was observed in groups receiving phytase (Phytase × LmPS, P < 0.05). In hens receiving FL, the APCD of P was lower in diets supplemented with phytase (-14 percentage points; Phytase × LmPS, P < 0.001). A higher phytate disappearance was observed in hens fed diets with phytase in combination with MIX (Phytase × LmPS, P = 0.005). Phytase and MIX together increased the APCD of Ca by 7.3 percentage points (Phytase × LmPS, P < 0.001). In conclusion, addition of CL could limit the formation of Ca-phytate complex thus improving the response of the birds to phytase compared to FL.

Evaluating a novel consensus bacterial 6-phytase variant on growth performance of broilers fed U.S. commercial diets deficient in nutrients and energy through 63 days of age

An experiment was conducted to evaluate the efficacy of a novel consensus bacterial 6-phytase variant expressed in Trichoderma reesei (PhyG) in broilers fed corn-soybean meal-based diets with application of dose-specific full nutrient and energy matrix values. Ross 708, straight-run broilers (n = 2,016) were assigned to one of 7 dietary treatments, with 12 replicate pens/diet and 24 birds/pen. Diets were a nutrient adequate control (PC), nutrient reduced negative controls 1, 2, and 3 (NC1, NC2, and NC3) with reductions in available phosphorus (avP) by 0.15%, 0.18%, and 0.19%, calcium (Ca) by 0.17%, 0.20%, and 0.21%, dig amino acids (AA) by 0.02%-0.05%, sodium (Na) by 0.03%-0.05%, and metabolizable energy (ME) by 62.8, 68.8, and 69.5 kcal/kg, respectively. Other diets were the NC1, NC2, and NC3 respectively supplemented with 500 (PhyG500), 1,000 (PhyG1000), and 2,000 (PhyG2000) FTU/kg. Over the 63-day feeding period, decreasing nutrient specifications lowered body weights (P < 0.05) in broilers from 4,518 g in PC to 4,256 g and 4,191 g and increased body weight-corrected feed conversion ratio (FCR, P < 0.05) from 1.92 in PC to 2.06 and 2.08 in the NC2 and NC3, respectively. Compared with PC, PhyG maintained (P > 0.05) BW in broilers fed PhyG500 (4,474 g), PhyG1000 (4,417 g), and PhyG2000 (4,449 g). Moreover, PhyG at all dose-levels maintained (P > 0.05) overall FCR vs. PC. The NC1, NC2, and NC3 diets decreased (P < 0.05) tibia ash vs. PC, and each PhyG500, PhyG1000, and PhyG2000 completely restored tibia ash to the similar levels (P > 0.05) as the PC. Carcass yield was decreased (P < 0.05) by NC1 (80.63%), NC2 (80.51%), and NC3 (80.31%) vs. PC (81.96%) with complete alleviation by PhyG500 (82.11%), PhyG1000 (81.80%), and PhyG2000 (81.54%). In conclusion, the novel consensus phytase variant completely compensated for the reduction in dietary avP, Ca, dig AA, and ME at each dose-level and maintained growth performance, bone quality, carcass characteristics, and nutrient digestibility in a typical corn-soybean mean based diet fed to broilers through 63 days of age.

Wide-genome selection of lactic acid bacteria harboring genes that promote the elimination of antinutritional factors

Anti-nutritional factors (ANFs) substances in plant products, such as indigestible non-starchy polysaccharides (α-galactooligosaccharides, α-GOS), phytate, tannins, and alkaloids can impede the absorption of many critical nutrients and cause major physiological disorders. To enhance silage quality and its tolerance threshold for humans as well as other animals, ANFs must be reduced. This study aims to identify and compare the bacterial species/strains that are potential use for industrial fermentation and ANFs reduction. A pan-genome study of 351 bacterial genomes was performed, and binary data was processed to quantify the number of genes involved in the removal of ANFs. Among four pan-genomes analysis, all 37 tested Bacillus subtilis genomes had one phytate degradation gene, while 91 out of 150 Enterobacteriacae genomes harbor at least one genes (maximum three). Although, no gene encoding phytase detected in genomes of Lactobacillus and Pediococcus species, they have genes involving indirectly in metabolism of phytate-derivatives to produce Myo-inositol, an important compound in animal cells physiology. In contrast, genes related to production of lectin, tannase and saponin degrading enzyme did not include in genomes of B. subtilis and Pediococcus species. Our findings suggest a combination of bacterial species and/or unique strains in fermentation, for examples, two Lactobacillus strains (DSM 21115 and ATCC 14869) with B. subtilis SRCM103689, would maximize the efficiency in reducing the ANFs concentration. In conclusion, this study provides insights into bacterial genomes analysis for maximizing nutritional value in plant-based food. Further investigations of gene numbers and repertories correlated to metabolism of different ANFs will help clarifying the efficiency of time consuming and food qualities.

Production systems and important antimicrobial resistant-pathogenic bacteria in poultry: a review

Economic losses and market constraints caused by bacterial diseases such as colibacillosis due to avian pathogenic Escherichia coli and necrotic enteritis due to Clostridium perfringens remain major problems for poultry producers, despite substantial efforts in prevention and control. Antibiotics have been used not only for the treatment and prevention of such diseases, but also for growth promotion. Consequently, these practices have been linked to the selection and spread of antimicrobial resistant bacteria which constitute a significant global threat to humans, animals, and the environment. To break down the antimicrobial resistance (AMR), poultry producers are restricting the antimicrobial use (AMU) while adopting the antibiotic-free (ABF) and organic production practices to satisfy consumers' demands. However, it is not well understood how ABF and organic poultry production practices influence AMR profiles in the poultry gut microbiome. Various Gram-negative (Salmonella enterica serovars, Campylobacter jejuni/coli, E. coli) and Gram-positive (Enterococcus spp., Staphylococcus spp. and C. perfringens) bacteria harboring multiple AMR determinants have been reported in poultry including organically- and ABF-raised chickens. In this review, we discussed major poultry production systems (conventional, ABF and organic) and their impacts on AMR in some potential pathogenic Gram-negative and Gram-positive bacteria which could allow identifying issues and opportunities to develop efficient and safe production practices in controlling pathogens.

Phytase dose-dependent response of kidney inositol phosphate levels in poultry

Phytases, enzymes that degrade phytate present in feedstuffs, are widely added to the diets of monogastric animals. Many studies have correlated phytase addition with improved animal productivity and a subset of these have sought to correlate animal performance with phytase-mediated generation of inositol phosphates in different parts of the gastro-intestinal tract or with release of inositol or of phosphate, the absorbable products of phytate degradation. Remarkably, the effect of dietary phytase on tissue inositol phosphates has not been studied. The objective of this study was to determine effect of phytase supplementation on liver and kidney myo-inositol and myo-inositol phosphates in broiler chickens. For this, methods were developed to measure inositol phosphates in chicken tissues. The study comprised wheat/soy-based diets containing one of three levels of phytase (0, 500 and 6,000 FTU/kg of modified E. coli 6-phytase). Diets were provided to broilers for 21 D and on day 21 digesta were collected from the gizzard and ileum. Liver and kidney tissue were harvested. Myo-inositol and inositol phosphates were measured in diet, digesta, liver and kidney. Gizzard and ileal content inositol was increased progressively, and total inositol phosphates reduced progressively, by phytase supplementation. The predominant higher inositol phosphates detected in tissues, D-and/or L-Ins(3,4,5,6)P4 and Ins(1,3,4,5,6)P5, differed from those (D-and/or L-Ins(1,2,3,4)P4, D-and/or L-Ins(1,2,5,6)P4, Ins(1,2,3,4,6)P5, D-and/or L-Ins(1,2,3,4,5)P5 and D-and/or L-Ins(1,2,4,5,6)P5) generated from phytate (InsP6) degradation by E. coli 6-phytase or endogenous feed phytase, suggesting tissue inositol phosphates are not the result of direct absorption. Kidney inositol phosphates were reduced progressively by phytase supplementation. These data suggest that tissue inositol phosphate concentrations can be influenced by dietary phytase inclusion rate and that such effects are tissue specific, though the consequences for physiology of such changes have yet to be elucidated.

Potential Probiotics Role in Excluding Antibiotic Resistance

Background. Antibiotic supplementation in feed has been continued for the previous 60 years as therapeutic use. They can improve the growth performance and feed efficiency in the chicken flock. A favorable production scenario could favor intestinal microbiota interacting with antibiotic growth promoters and alter the gut bacterial composition. Antibiotic growth promoters did not show any beneficial effect on intestinal microbes. Scope and Approach. Suitable and direct influence of growth promoters are owed to antimicrobial activities that reduce the conflict between host and intestinal microbes. Unnecessary use of antibiotics leads to resistance in microbes, and moreover, the genes can relocate to microbes including Campylobacter and Salmonella, resulting in a great risk of food poisoning. Key Findings and Conclusions. This is a reason to find alternative dietary supplements that can facilitate production, growth performance, favorable pH, and modulate gut microbial function. Therefore, this review focus on different nutritional components and immune genes used in the poultry industry to replace antibiotics, their influence on the intestinal microbiota, and how to facilitate intestinal immunity to overcome antibiotic resistance in chicken.

Nutritional evaluation of crambe meal as a partial replacement of soybean meal in Nile tilapia diet

A variety of plant protein sources have been evaluated in aquafeeds. Crambe meal (CM) has potential for inclusion in fish diets because of its nutritional composition. This study evaluated the apparent digestibility coefficient (ADC) of crambe meal and its potential to partially replace soybean meal (SM) protein in Nile tilapia Oreochromis niloticus diets. The ADC for dry matter, crude protein, ether extract, energy, amino acids, calcium and phosphorus of CM were assessed in fish (n = 80; 65.30 ± 5.32 g). Subsequently, an 80-day feeding trial was conducted with Nile tilapia (n = 140; 6.04 ± 0.25 g) randomly distributed in 20 experimental cages (70 L; seven fish cage^-1) allocated in five circular tanks (1000 L) in a recirculation water system, to evaluate the effects of replacement of SM by CM (0, 6, 12, 18 and 24% in isonitrogenous and isoenergetic diets) on growth, blood parameters, fillet yield and proximal composition. The CM shows good digestibility of protein (0.824) and amino acids (0.844) by Nile tilapia and its inclusion in the diet does not affect carcass and fillet yield or proximal composition. Fish fed diets with 24.0% of the SM replaced by CM showed the worst weight gain and feed conversion rate. The protein efficiency ratio decreased in fish fed diets with 12.0, 18.0 and 24.0% of the SM replaced by CM. Hemoglobin, mean corpuscular hemoglobin concentration, total plasma protein, glucose and alanine aminotransferase enzyme activity trend to increase at highest levels of CM in the diet. In conclusion, CM has high digestibility of protein and amino acids for Nile tilapia. However, anti-nutritional factors present in untreated CM interfere on the growth and nutrient utilization of Nile tilapia.

The use of Enzymes in Meat Quail Diets Containing Sunflower Seed Cake

We examined the effects of including sunflower cake (SC) associated with an enzyme complex (EC) in the diet of meat quails on nutrient metabolism, performance, carcass characteristics, bone parameters and economic viability. In total, 432 meat quails (7 to 42 days old) were assigned to six treatments in a completely randomised design with 6 replicates with 12 birds each. A 2 × 3 factorial arrangement was adopted (two levels of SC: 10 and 20%; three diet formulation strategies: normal, reduction in the nutrient and energy matrix considering the enzymatic contribution and reduced diet with EC). No interaction effect was observed. The increased levels of SC from 10% to 20% promoted in decrease in the metabolisability coefficients of dry matter and gross energy and in the value of AMEn and increased relative weight of gizzard. The addition of EC in diets containing SC allows a better metabolization of nitrogen and energy, equalize to the normal diet. The best breast yield was obtained in the birds fed the reduced diet with EC, in relation to normal diet. The reduced diet and the reduced diet with EC provided the lowest cost of food and the best economic efficiency index. Up to 20% of the sunflower cake can be included in the diet of cut quail, with or without enzyme supplementation. However, the use of the enzyme complex composed of carbohydrases, proteases and phytase can favor the metabolization of nitrogen and energy from the diet containing sunflower cake.

Review: Bioavailability of trace elements in farm animals: definition and practical considerations for improved assessment of efficacy and safety

Currently, the authorisation procedure of trace elements as feed additives in the European Union according to Regulation (EC) No. 1831/2003 does not consider the bioavailability of trace element sources. This manuscript provides framework conditions for in vivo experiments that aim to estimate differences in the relative bioavailability between supplements of essential trace elements. Framework conditions encompass necessary technical information on the test substance, the experimental design and diet composition as well as the suitability of status parameters that allow for relative comparisons of regression variables. This manuscript evolves recommendations for researchers to conduct solid and reliable experiments on the matter as well as decision makers to interpret the value of studies submitted with authorisation applications regarding a certain trace element supplement.

Effect of Phytase Level and Form on Broiler Performance, Tibia Characteristics, and Residual Fecal Phytate Phosphorus in Broilers from 1 to 21 Days of Age

The present study evaluated the individual and combined effects of coated and uncoated phytase on broiler performance, tibia characteristics, and residual phytate phosphorus (P) in manure. Two repeated studies were conducted using 240-day-old Cobb 500 by-product male broilers per trial. For each trial, birds were assigned to four treatments with four replicate battery cages per treatment (60 birds/trt) and grown for 21 days. Treatments included: (1) negative control (NC), (2) NC + 1000 phytase units (FTU) coated phytase (C), (3) NC + 1000 FTU uncoated phytase (U), and (4) NC + 500 FTU coated + 500 FTU uncoated phytase (CU). Data were analyzed with a one-way ANOVA and means were separated using Tukey’s HSD. In the pooled data for both trials, all treatments with dietary phytase had a higher body weight (BW) and feed consumption (FC) than the NC on day 21 (p < 0.05). Similarly, a six-point reduction was observed for day 1 to 21 feed conversion (FCR) for U and CU (p < 0.05). All treatments with phytase inclusion differed from the NC in every evaluated parameter for bone mineralization (p < 0.05) and had significantly lower fecal phytate P concentrations compared to the NC (p < 0.05). Overall, bird performance was essentially unaffected by phytase form, indicating that combining phytase forms does not appear to offer any advantage to the evaluated parameters from day 1 to 21.

Effects of phytase and coccidial vaccine on growth performance, nutrient digestibility, bone mineralization, and intestinal gene expression of broilers

A study was conducted to evaluate effects of phytase and coccidial vaccine on growth performance, bone mineralization, nutrient digestibility, and intestinal gene expression of broiler chickens. The experiment was conducted in a 2 × 4 completely randomized factorial arrangement with 6 replicates per treatment and 10 birds each. Applications of coccidiosis vaccine and different dietary treatments were the 2 main factors in the current study. The dietary treatments included 1) a positive control (PC; 0.90% Ca and 0.45% available P: avP); 2) a negative control (NC; 0.75% Ca and 0.30% AvP); 3) NC + 500 FTU/kg of phytase (NC + 500PHY); and 4) NC + 1500 FTU/kg of phytase (NC + 1500PHY). Data were analyzed using SAS by 2-way ANOVA via GLM procedure. The statistical significance was set at P ≤ 0.05, and means were further separated using Tukey's Test. The results indicated that vaccination had no effect on growth performance except for feed intake from 0 to 14 d but negatively (P < 0.05) regulated bone ash and Ca digestibility. Birds fed with the Ca and P-reduced diet (NC) showed a lower BWG and bone ash compared to birds fed with the normal diet (PC), but supplementing phytase mitigated the negative effects on those birds. Broilers fed the NC diet had higher (P < 0.05) total Ca and P digestibility, and phytate degradation; supplementing phytase further increased P digestibility and phytate degradation of the broilers. A significant interaction (P < 0.05) between phytase and vaccination was observed, suggesting the vaccinated birds fed the PC diet and the unvaccinated birds fed the NC + 1500PHY increased calcium-sensing receptor gene expression compared with the unvaccinated birds fed the PC diet. In conclusion, in spite of coccidiosis vaccine, supplementing phytase at 1,500 FTU/kg alleviated the negative effects on growth performance, bone mineralization, and apparent ileal digestibility of P and phytate.

Efficacy of Various Feed Additives on Performance, Nutrient Digestibility, Bone Quality, Blood Constituents, and Phosphorus Absorption and Utilization of Broiler Chickens Fed Low Phosphorus Diet

The present trial was designed to assess the effect of phytase, multi-strain probiotic, Saccharomyces cerevisiae, and fumaric acid on performance, nutrient digestibility, bone physical parameters and mineralization, blood constituents, bone and gut histomorphology, and duodenal phosphorus transporter genes of broiler chickens fed a decreased non-phytate phosphorus (nPP) diet for 5 weeks. A total of 480 broiler chickens were allotted to six dietary groups and eight replicates each: (1) positive control diet with recommended levels of nPP (PC; 0.48, 0.44, and 0.41% in the three feeding phases); (2) negative control diet with a decreased dietary nPP (NC; 0.28, 0.24, and 0.21% in the three feeding phases); (3) NC + 600 FTU/kg phytase (PHY); (4) NC + 0.05% multi-strain probiotic (PRO); (5) NC + 0.2% Saccharomyces cerevisiae (SC); and (6) NC + 0.2% fumaric acid. Growth performance data were recorded weekly, and blood sampling was performed at days 21 and 35 of age. Bone quality traits, gut and tibia histology, nutrient digestibility, and intestinal gene expression analyses were conducted at the end of the trial (35 days of age). Final body weight and total gain at day 35 of age of the broiler chickens fed with the PHY, PRO, and SC diets were greater (p < 0.01) than in NC, where broilers fed with the PRO and PHY diets had higher values and were similar to that of PC. There was a non-significant variation in the cumulative feed intake among the treatment groups. The PHY and PRO groups had better FCR than the PC group (p < 0.05), and FA and SC had an FCR equivalent to that of PC. The PHY and PRO broilers had greater dressing % than the NC group (p < 0.05) and even better than PC. The PHY, PRO, SC, and FA broilers had higher relative weights of spleen and bursa of Fabricius (p < 0.01) than NC. In comparison to NC, the PHY, PRO, and SC groups improved (p < 0.05) CP, CF, Ca, and P digestibility. Greater tibia breaking strength of the low nPP-supplemented groups was shown to be associated with higher tibia ash, Ca, and P concentrations (p < 0.01) and increased (p < 0.001) tibia cortical area thickness. At days 21 and 35 of age, the dietary supplements to low nPP diets reduced (p < 0.05) serum total cholesterol, triglyceride, triiodothyronine, thyroxine, glucose, and alkaline phosphatase levels, while serum Ca and P concentrations were improved (p < 0.05) compared to NC. All supplements led to enhancement (p < 0.01) in villi height and width and villi absorptive surface area when compared with NC and were even comparable to that of PC. The mRNA expression of NaP-IIb was up-regulated (p < 0.001) in the duodenum of PRO and FA broilers at day 35 of age compared with NC, and their expression levels were similar to that of PC, indicating greater P availability. It is concluded that dietary supplementation of PHY, PRO, SC, and FA to a low nPP diet was advantageous and mitigated the negative impacts of P reduction on the growth performance, health, nutrient digestibility, and bone quality of broilers.

Alginate Particles for Enzyme Immobilization Using Spray Drying

Enzymes are important catalysts for biological processes due to their high catalytic activity and selectivity. However, their low thermal stability limited their industrial applications. The present work demonstrates a simple and effective method for enzyme immobilization via spray drying. Alginate was used as a support material. Phytase, an important enzyme in the animal feed industry, was selected to study the effect of enzyme immobilization using alginate particles on its thermal stability. The physicochemical properties of alginate particles such as size, surface morphology, and heat resistance were studied. Successful immobilization of phytase was confirmed by confocal microscopy, and the immobilized phytase retained 58% of its original activity upon heating at 95 °C, compared to 4% when the alginate support material was absent. Phytase was released promptly in a simulated gastrointestinal tract with >95% of its original activity recovered. The spray drying method for phytase immobilization is scalable and applicable to other enzymes for various applications.

The Duration of the Trial Influences the Effects of Mineral Deficiency and the Effective Phytase Dose in Broilers' Diets

Two trials varying in duration (short- and long-term) were conducted to evaluate the effects of providing deficient (NC) or sufficient (PC) Ca and P levels, and different doses of a new phytase (250, 500, and 1000 FTU/kg feed), in broiler feed on growth performance, nutrient digestibility and retention, and tibia mineralization. A total of 80 and 490 male chicks (Ross) of 21 and 1 days of age were used in the short- and long-term trials, respectively. In the long-term trial, chicks fed NC diets showed a lower (p < 0.05) average daily gain and feed intake compared to chicks fed PC and a greater (p < 0.05) feed conversion ratio compared to 500 and 1000 FTU/kg feed during the starting period. Regarding the effects on minerals’ and nutrients’ coefficients of retention, animals fed NC showed a significantly higher digestibility for P than those fed the PC diet in the long-term trial. Additionally, feeding 250 to 500 FTU/kg diets increased most of the nutrients’ digestibility in the short-term but only P digestibility in the long-term trial. Tibia mineralization increased linearly with phytase addition (p < 0.05) only in the long-term trial. In conclusion, the effects of dietary mineral and phytase levels on growth performance are more noticeable in young animals. In addition, the duration of the trial is key due to a possible adaptation phenomenon of birds to low P supplementary levels.