Growth performance and nutrient utilization of broiler chickens fed diets supplemented with phytase alone or in combination with citric acid and multicarbohydrase

Effects of Dietary Multi-Carbohydrase and Phytase Complex Supplementation on Nutrient Digestibility, Bone Mineralization and Puberty Onset in Gilts

The study was conducted to determine the effects of multi-carbohydrase and phytase complex (MCPC) supplementation in standard and commercial diets on growth performance, nutrient digestibility, bone mineralization, blood biochemical parameters and puberty onset in gilts. A total of 144 healthy gilts (Duroc × (Landrace × York)) were assigned randomly to four treatments (n = 36), with 10 replicate pens (6 pens, each containing 4 gilts, and 4 pens, each containing 3 gilts). The trial consisted of two phases (phase 1: 70-100 kg; phase 2: 100-140 kg). The commercial diet (COM) had 33% higher calcium (Ca) and phosphorus (P) levels than the standard diet (CON) across all phases. The four treatment diets were as follows: CON (phase 1: 0.56 g/kg Ca and 0.49 g/kg P; phase 2: 0.49 g/kg Ca and 0.45 g/kg P), COM (phase 1: 0.75 g/kg Ca and 0.65 g/kg P; phase 2: 0.65 g/kg Ca and 0.60 g/kg P), CON + MCPC and COM + MCPC, where both the CON and COM diets were supplemented with 100 mg/kg of MCPC, respectively. The commercial diet significantly (p < 0.05) increased the total number of follicles and the number of follicles < 4 mm and tended to reduce (p = 0.07) the age at puberty compared to the standard diet. Besides, MCPC supplementation improved the apparent total-tract digestibility (ATTD) of Ca (p < 0.05), P (p < 0.05) and Ash (p = 0.07) in gilts during phase 1, compared to the basal diets without MCPC supplementation. Additionally, MCPC supplementation significantly elevated serum creatinine (CREA, p < 0.05) concentrations and had a tendency to increase serum Ca (p = 0.07) concentrations in gilts. Specifically, COM + MCPC supplementation significantly increased the osteocalcin (OCN) concentration compared with the COM treatment. Moreover, dietary MCPC supplementation significantly improved the bone strength (p < 0.05) compared to the basal diets without MCPC supplementation. In conclusion, dietary MCPC supplementation increased the ATTD of Ca and P in gilts, while also improving bone strength. This improvement not only extends the reproductive lifespan of sows, but it also allows for reduced supplementation levels of Ca and P in the dietary formula.

Optimizing broiler growth, health, and meat quality with citric acid- assessing the optimal dose and environmental impact: Citric acid in Broiler Health and Production

The need for sustainable and safe alternatives to antibiotic growth promoters has driven researchers to explore organic acids (OAs) inclusion in broiler diets. Citric acid (CA), a notable OA, has emerged as a promising alternative due to its various physiological benefits, including improved nutrient digestibility, antioxidant properties, and enhanced weight gain. Despite the improved growth performance, the feed conversion ratio (FCR) does not seem to be consistently affected by CA inclusion. A considerable number of research papers suggest that CA can replace antibiotic growth promoters and has proved to be more effective when combined with other additives like probiotics and microbial phytase. However, despite numerous trials, the near-accurate dose remains in doubt. Dietary addition between 1.65 % and 2.65 % seems to positively affect broiler performance. Being an organic acid, CA brings no risk to the environment and does not economically burden producers. It has the capability to enhance certain meat qualities and extend shelf life. However, there is a risk of acidic stress and liver damage with excessive inclusion. This review study seeks to offer a thorough and all-encompassing summary of the present level of understanding regarding the use of CA supplementation in broiler diets by describing its impacts on growth efficiency, nutrient utilization, intestinal condition, immune response, meat quality, optimal dose, and environmental sustainability. Further research focused on determining precise dosage levels and understanding the synergistic or antagonistic effects of citric acid when combined with other feed additives is essential for optimizing broiler performance.

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.

The Effect of including a Mixed-Enzyme Product in Broiler Diets on Performance, Metabolizable Energy, Phosphorus and Calcium Retention

The importance of enzymes in the poultry industry is ever increasing because they help to extract as many nutrients as possible from the raw material available and reduce environmental impacts. Therefore, an experiment was conducted to examine the effect of a natural enzyme complex (ASC) on diets low in AME, Ca and P. Male Ross 308 broilers (n = 900) were fed one of four diets: (1) positive control (PC) with no enzyme added (AME 12.55 MJ/kg, AVPhos 4.8 g/kg and AVCal 9.6 g/kg); (2) negative control (NC) with no enzyme added and reduced AME, Ca and P (AME 12.18 MJ/kg, AVPhos 3.3 g/kg, AVCal 8.1 g/kg); (3) negative control plus ASC at 200 g/t; and (4) negative control plus ASC at 400 g/t. Broiler performance, digesta viscosity, tibia mineralization and mineral content were analyzed at d 21. Between d 18 and 20, excreted DM, GE, total nitrogen, Ca, and P were analyzed. ASC at 200 g/t and 400 g/t improved the FCR (p = 0.0014) significantly when compared with that of the NC. There were no significant differences in BW or FI between the treatments. Birds fed ASC at 200 g/t and 400 g/t had significantly improved digesta viscosity (p < 0.0001) compared with that of the PC and NC birds and had significantly higher excreted DM digestibility (p < 0.01) than the NC and the PC birds with 400 g/t ASC. ASC inclusion significantly improved P retention (p < 0.0001) compared to that in the PC. Ca retention was significantly increased by 400 g/t ASC compared to that in the PC and NC (p < 0.001). AME was significantly higher (p < 0.0001) for all treatments compared to that in the NC. There were no significant differences between treatments for any of the bone measurements. This study showed that feeding with ASC can support the performance of broilers when fed a diet formulated to have reduced Ca, P and AME, with the greatest results being seen with a higher level of ASC inclusion.

A study of solely used phytase or in combination with multi-carbohydrase on growth performance along with tibia mineralization, and carcass traits in broilers fed nutrient-deficient diets

The objective of this study aimed to investigate the effectiveness of phytase alone and in combination with multi-carbohydrase in available phosphorus (AP) and energy-deficient diets on growth performance, nutrient digestibility, tibia traits, and carcass quality of broilers. A total of 288 1-d-old Ross 308 broiler chicks were randomly assigned to one of 6 dietary treatments in a completely randomized design, with each treatment having 6 replicates and 8 birds per cage. The treatments were as follows: 1) positive control with adequate nutrition (PC); 2) 0.20% AP-deficient diet without phytase (NC-1); 3) 0.25% AP-deficient diet without phytase (NC-2); 4) NC-1 diet plus 500 FTU/kg phytase (NCP-1); 5) NC-2 diet plus 750 FTU/kg phytase (NCP-2); and 6) NC-2 with 100 kcal/kg ME deficient diet plus 1,000 FTU/kg phytase and multi-carbohydrase: 2,200 U/kg galactomannanase, 30,000 U/kg xylanase, 22,000 U/kg β-glucanase, and 700 U/kg α-galactosidase (NCPM). Broilers in the PC group and those fed enzyme-supplemented diets exhibited greater (P < 0.05) growth performance in terms of body weight, average daily gain, and feed conversion ratio, along with enhanced tibia mineralization through the ash, calcium (Ca), phosphorus (P) composition, and tibia breaking strength compared to NC diets throughout the study. Among the treatments, broilers assigned to the NCPM group showed greater (P < 0.05) levels of energy and P digestibility on days 21 and 35. Concerning carcass characteristics, the leg meat yield was greater (P < 0.05) in broilers fed the NCP-2 diet compared to all other treatments on days 21 and 35. Supplementation of phytase at doses of 500 FTU/kg and 750 FTU/kg effectively recovers AP deficiencies of 0.20% and 0.25%, respectively, in broiler diets without compromising the growth performance of broilers. Additionally, combining multi-carbohydrase and phytase led to AP and energy loss recovery, which improved tibia mineralization and nutrient digestibility through their synergistic interaction.

Nutritional and Functional Roles of Phytase and Xylanase Enhancing the Intestinal Health and Growth of Nursery Pigs and Broiler Chickens

This review paper discussed the nutritional and functional roles of phytase and xylanase enhancing the intestinal and growth of nursery pigs and broiler chickens. There are different feed enzymes that are currently supplemented to feeds for nursery pigs and broiler chickens. Phytase and xylanase have been extensively studied showing consistent results especially related to enhancement of nutrient digestibility and growth performance of nursery pigs and broiler chickens. Findings from recent studies raise the hypothesis that phytase and xylanase could play functional roles beyond increasing nutrient digestibility, but also enhancing the intestinal health and positively modulating the intestinal microbiota of nursery pigs and broiler chickens. In conclusion, the supplementation of phytase and xylanase for nursery pigs and broiler chickens reaffirmed the benefits related to enhancement of nutrient digestibility and growth performance, whilst also playing functional roles benefiting the intestinal microbiota and reducing the intestinal oxidative damages. As a result, it could contribute to a reduction in the feed costs by allowing the use of a wider range of feedstuffs without compromising the optimal performance of the animals, as well as the environmental concerns associated with a poor hydrolysis of antinutritional factors present in the diets for swine and poultry.

Energy values evaluation and improvement of soybean meal in broiler chickens through supplemental mutienzyme

This study measured the metabolizable energy of soybean meal (SBM) and evaluated effects of soybean meal specific enzymes supplementation in corn-soybean diets on growth performance, intestinal digestion properties and energy values of 28-day-old broilers. A total of 336 one-day-old male AA broiler chickens were distributed to 7 groups in a completely random design. The birds were given 7 diets containing 6 diets with different combined soybean meals and a fasting treatment, 8 replicates per treatment and 6 birds per replicate (Trial 1). A total of 672 one-day-old male AA broiler chickens were randomly allocated to 7 dietary treatments including a control diet and 6 diets supplemented with 300 mg/kg α-galactosidase, 200 mg/kg β-mannanase, and 300 mg/kg protease individually or in combination (Trial 2). Apparent metabolizable energy (AME) of broilers was measured from d 25 to 27 in both trial 1 and trial 2. The results showed that AME values of combined soybean meals averaged 2,894 kcal/kg. Dietary β-mannanase and protease supplementation increased body weight gain (P < 0.05) during d 0 to 14, whereas did not affect the growth performance (P > 0.05) during d 14 to 28. Addition of β-mannanase in combination with other enzymes significantly increased lipase and trypsin content (P < 0.05) in ileum. In addition, dietary β-mannanase and protease supplementation individually or in combination enhanced trypsin enzyme content in jejunum (P < 0.05). The β-mannanase enzyme enhanced villus height and villus height to crypt depth ratio (P < 0.05) of ileum compared with control diet. Moreover, supplementation of enzyme except for protease enhanced raffinose and stachyose degradation ratio (P < 0.05). Dietary β-mannanase supplementation individually or in combination enhanced AME and AMEn values (P < 0.05). This study demonstrated that dietary enzyme supplementation especially β-mannanase improved intestinal digestion properties and contributed to high energy values.

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 Flaxseed and Multi-Carbohydrase Enzymes on the Cecal Microbiota and Liver Inflammation of Laying Hens

Simple Summary

Wheat and flaxseed are used worldwide to produce omega-3 (ω-3) enriched poultry meat and eggs, however, wheat and flaxseed contain some anti-nutritional factors (ANFs). In addition, the supplementation of feed additive including enzymes usually alleviate the deleterious influence of ANFs. Therefore, we conducted the current study of laying hens fed with two diets (corn/flaxseed and wheat/flaxseed, supplemented with three enzymes), for a period of 10 weeks. Here, we found a clear increase in the fat weight of birds fed with corn diet as compared with wheat diet. Moreover, a high level of secretory IL-1β, IL-6, and IL-10 and comparatively higher inflammatory changes in the liver tissue were found in birds fed with corn diet as compared with wheat diet. The gut microbial composition of hens fed with corn diet was clearly different than that of birds fed a wheat diet. In conclusion, our findings suggest that inflammatory changes in laying birds were mediated by a corn diet with flaxseed and enzymes instead of a wheat diet. Additionally, in the wheat-fed group, enzyme-b and -c showed more encouraging results as compared to enzyme-a indicating that wheat diet might be a preferable diet for commercial layers poultry farms.

Abstract

Background: The use of wheat and flaxseed to produce omega-3 (ω-3) enriched poultry meat and eggs is very popular in the world. However, wheat and flaxseed contain some anti-nutritional factors (ANFs), and enzymes are usually used to alleviate the deleterious influence of ANFs. Method: A 2 × 3 two factors design was used in the experiment. A total of 540 twenty-week-old Nongda-3 laying hens were randomly allocated to six dietary treatments, two diets (corn/flaxseed and wheat/flaxseed), and three enzymes (enzyme-a contains neutral protease 10,000, xylanase 35,000, β-mannanase 1500, β-glucanase 2000, cellulose 500, amylase 100, and pectinase 10,000 (U g⁻¹); enzyme-b contains alkaline protease 40,000 and neutral protease 10,000 (U g⁻¹); enzyme-c contains alkaline protease 40,000, neutral protease 10,000, and cellulase 4000 (U g⁻¹). Results: There was an interaction between dietary treatment and supplemental enzymes for liver weight and liver inflammatory cytokines of broilers. A significant increase was observed in the fat weight of birds fed a corn diet as compared with a wheat diet. A corn diet and wheat diet with the addition of enzyme-a (p < 0.001) showed the highest level of liver fat followed by enzyme-c (p < 0.01) and enzyme-b. Moreover, a high level of secretory IL-1β, IL-6, and IL-10 and comparatively higher inflammatory changes in the liver tissue were found in birds fed a corn diet as compared with a wheat diet, and enzyme-b showed more beneficial effects as compared with enzyme-a and -c. The gut microbial composition of hens fed a corn diet was significantly different than that of birds fed a wheat diet. Bacteroides were significantly (p < 0.05) abundant in the corn-fed birds as compared with wheat-fed birds. However, Firmicutes were less abundant in the wheat-fed birds than the corn-fed birds (16.99 vs. 31.80%, respectively). The microbial community at the genus level differed significantly in the dietary groups and we observed that Bacteroides are the predominant cecal microbiota. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of co-factors, carbohydrates, vitamins, protein, and energy were expressed at slightly higher levels in the microbiota of the wheat-fed birds, whereas, metabolic pathways for nucleotides, lipids, and glycine were expressed at higher levels in the wheat-fed birds. Furthermore, expression of the growth and cellular processes pathway and endocrine system pathway levels were predicted to be higher for the wheat-fed group as compared with the corn-fed group. Conclusions: In conclusion, our findings suggest that inflammatory changes in laying birds were mediated by a corn diet with flaxseed and enzymes instead of a wheat diet. Additionally, in the wheat-fed group, enzyme-b and -c showed more encouraging results as compared to enzyme-a.

Effect of crop retention time and acidification of the feed on phytase efficacy in broiler chickens

1. An in vitro test to study the effect of pH reduction on phytic acid degradation over time for four commercial phytases was conducted. Changing the pH level affected phytate degradation over time differently for the various phytases (P < 0.05).2. The phytase with the largest response of pH reduction in the in vitro test and a feed pH level of 4.5 was chosen for the broiler experiment. The effect of intermittent feeding, addition of 500 FYT C. braakii-derived phytase and 1% formic acid were tested in a 2 x 2 x 2 factorial arrangement. Ten pens containing 10 birds each were fed each of the treatment combinations from 15 to 36 d of age. Ad libitum fed birds had two 4-h dark periods with 2-h light in-between, while intermittently fed birds in addition had restricted access to the feed through except for four 1-h and one 2-h feeding bouts.3. In addition to assessing performance, excreta were collected on a pen basis. The tibia and contents from jejunum and ileum were collected from one bird per pen. In addition, crop contents were collected from the intermittently fed birds 80, 160 and 240 min after the start of feeding.4. Phytase improved performance, ileal and jejunal P digestibility, P retention and tibia ash and P concentration (P < 0.001). Intermittent feeding increased jejunal P digestibility and P retention (P < 0.001), but ileal P digestibility increased only in the intermittently fed birds compared to the ad libitum fed birds without phytase addition (P = 0.025). Acidification increased jejunal P digestibility only in the ad libitum fed birds (P = 0.019). There was a considerable inositol hexakisphosphate degradation into lower isomers in the crop after 80 min for diets with phytase (InsP_{3 and 4}:P < 0.001), and acidification further increased this degradation (InsP₄:P = 0.007). After 160 min retention time, the effect of phytase and acidification was even higher with more significant (P < 0.05) interactions.5. The current data showed that prolonged retention time in the crop combined with feed acidification increased phytase efficacy by improving the phytate degradation.

Growth performance and nutrient digestibility of growing and finishing pigs fed multienzyme-supplemented low-energy and -amino acid diets

A study was conducted to determine the effects of supplementing corn-soybean meal-based diets with a multienzyme on growth performance, bone mineralization, apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of nutrients of growing pigs. A total of 276 pigs (body weight [BW] = 33.99 ± 4.3 kg) were housed by sex in 45 pens of 6 or 7 pigs and fed 5 diets (9 pens/diet) in a randomized complete block design. Diets were positive control (PC); and negative control 1 (NC1) or negative control 2 (NC2) without or with multienzyme. The multienzyme used supplied at least 1,800, 1,244, 6,600, and 1,000 units of xylanase, β-glucanase, arabinofuranosidase, and phytase per kilogram of diet, respectively. The PC diet was adequate in all nutrients according to NRC recommendations and had greater digestible P content than NC1 or NC2 diet by 0.134 percentage points. The PC diet had greater net energy (NE) and standardized ileal digestible amino acids (AA) content than NC1 diet by 3%, and than NC2 diet by 5%. The diets were fed in 4 phases based on BW: Phase 1: 34-50 kg; Phase 2: 50-75 kg; Phase 3: 75-100 kg; and Phase 4: 100-120 kg. Nutrient digestibility and bone mineralization were determined at the end of Phase 1. Overall (34-120 kg BW), pigs fed the PC and NC1 diets did not differ in average daily gain (ADG) and average daily feed intake. Pigs fed NC2 diet had lower (P < 0.05) ADG and gain-to-feed ratio (G:F) than those fed PC diet. Pigs fed PC diet had greater (P < 0.05) bone ash content and ATTD of P than those fed NC1 diet. The ATTD of GE for PC diet was greater (P < 0.05) than that for NC2 diet, and tended to be greater (P < 0.10) than that for NC1 diet. Multienzyme interacted (P < 0.05) with negative control diet type on overall ADG and AID of GE such that multienzyme did not affect overall ADG and AID of GE for the NC1 diet, but increased (P < 0.05) overall ADG and AID of GE for NC2 diet by 5.09 and 8.74%, respectively. Multienzyme did not interact with negative control diet type on overall G:F, bone ash content, AID of AA, and ATTD of nutrients. Multienzyme increased (P < 0.05) overall G:F, AID of methionine, ATTD of GE and P, and tended to increase (P = 0.056) bone ash content. The ADG, bone ash content, and ATTD of GE and P for the multienzyme-supplemented diets were similar to (P > 0.10) PC diet. Thus, NE and digestible AA and P can be lowered by ≤5% in multienzyme-supplemented diets without effects on growth performance and bone ash of pigs.

Interactive effect of 2 dietary calcium and phytase levels on broilers challenged with subclinical necrotic enteritis: part 1-broiler performance, gut lesions and pH, bacterial counts, and apparent ileal digestibility

This study investigated the hypothesis that high dietary calcium (Ca) would stimulate necrotic enteritis (NE) and reduce performance, gut health, and nutrient digestibility, and if increased, phytase would reduce NE. Ross 308 male broilers (n = 768) were randomly distributed to 8 treatments in a factorial arrangement. Factors were NE challenge (no or yes), phytase level (500 or 1,500 FTU/kg using 500 FTU/kg matrix values), and Ca level (0.6 or 1.0% starter, 0.5 or 0.9% grower, 0.4 or 0.8% finisher) with the same level of available P (0.40 S, 0.35 G, and 0.35 F). There were 48 pens, 16 birds per pen and 6 replications. Half of the birds were challenged with Eimeria spp on day 9 and 10⁸ CFU per mL of Clostridium perfringens strain EHE-NE18 on day 14 and 15. Gain was higher in birds fed high phytase on day 14 (P < 0.01), day 21 (P < 0.01), day 28 (P < 0.01), and day 35 (P < 0.01). Birds fed high phytase had greater livability on day 21 (P < 0.01). Ca was more digestible in high-Ca diets on day 16, and an NE × Ca interaction (P < 0.05) showed this effect to be more pronounced in unchallenged than in challenged birds. A challenge × Ca interaction for apparent ileal digestibility (AID) of crude protein (CP) (P < 0.05) indicated lower AID of CP in challenged birds fed high Ca. The challenge decreased AID of Ca (P < 0.01). Ca level had no impact on C. perfringens count, but it decreased Lactobacillus (P < 0.05) and Bifidobacteria (P < 0.05) populations in the ceca. High dietary Ca decreased feed conversion ratio. Overall (42 D), the highest WG was observed in unchallenged birds fed high Ca and high phytase with the lowest WG observed in NE-challenged birds fed low Ca and low phytase. The results suggest that full matrix values for high doses of phytase may be appropriate during NE challenge.

Volatile basic nitrogen measurement in digesta using a Berthelot reaction in automated Skalar instrumentation

The undigested nitrogenous fraction entering the hindgut of chickens is further metabolized by microbiota present producing volatile basic metabolites including amines and ammonia (NH3). Ammonia increases pH and may result in overgrowth of Clostridium perfringens further producing toxic metabolites that cause dysbacteriosis or necrotic enteritis (NE). There are few reports in chickens examining the production and concentration of nitrogenous metabolites in the hindgut. A Berthelot reaction using an automated flow, reaction and spectrophotometric instrumentation to detect volatile basic nitrogen in the form of NH3 from cecal contents was carried out. In the Berthelot reaction, NH3 in the sample is chlorinated to monochloramine using dichloroisocyanuric acid that then reacts with salicylate to form 5-aminosalicylate which is stable under alkaline conditions (pH 12 to 13). After oxidation and oxidative coupling, a coloured complex is formed that can be measured at 660 nm. Cecal contents were collected and pooled from 2 birds per pen with 48 pens total in each of 3 experiments and stored in sealed containers at -20 °C prior to analysis. Experiment 1 compared samples collected from birds fed either no meat and bone meal (MBM) or 6% MBM from d 0 to 14, and samples collected from birds fed either no MBM or 5% MBM from d 14 to 42. All birds were challenged with Eimeria on d 9 and C. perfringens on d 14 and 15. Experiment 2 compared cecal contents from birds fed either 0.5% or 0.9% calcium (Ca), and Exp. 3 compared unchallenged with NE challenge on d 16 and 29. Results demonstrated an increase (P < 0.05) in cecal NH3 as a result of feeding MBM or high dietary Ca with a corresponding increase in pH. Birds experimentally challenged with NE had lower cecal NH3 and lower pH on d 16 but not d 29 compared to unchallenged controls. It was concluded that the Berthelot method using Skalar instrumentation equipment is suitable to measure the concentration of volatile nitrogen as NH3 in cecal contents of chickens.

Nutrient digestibility of multi-enzyme supplemented low-energy and AA diets for grower pigs1

A study was conducted to determine effects of supplementing multi-enzyme on apparent ileal digestibility (AID) of energy and AA; and apparent total tract digestibility (ATTD) of energy for pigs fed low-energy and AA diets. Eight ileal-cannulated barrows (initial BW: 38.7 ± 2.75 kg) were fed four diets in a replicated 4 × 4 Latin square design to give 8 replicates per diet. Diets were positive control (PC) diet, negative control (NC) diet without or with multi-enzyme at 0.5 or 1.0 g/kg. The PC diet was formulated to meet or exceed NRC (2012) nutrient recommendations for grower pigs (25 to 50 kg), except for Ca and digestible P, which were lower than NRC (2012) recommendations by 0.13 and 0.17 percentage points, respectively, due to phytase supplementation at 1,000 FTU/kg. The NC diet was formulated to be lower in NE by 75 kcal/kg and standardized ileal digestible AA content by a mean of 3%. These reductions were achieved by partial replacement of corn and soybean meal (SBM) and complete replacement of soybean oil and monocalcium phosphate in PC diet with 25% corn distillers dried grains with solubles (DDGS) and 3.6% soybean hulls. Multi-enzyme at 1.0 g/kg supplied 1,900 U of xylanase, 300 U of β-glucanase, 1,300 U of cellulase, 11,500 U of amylase, 120 U of mannanase, 850 U of pectinase, 6,000 U of protease, and 700 U of invertase per kilogram of diet. The AID of GE, N, most AA, most component sugars of nonstarch polysaccharides (NSP) and P; ATTD of GE for PC diet was greater (P < 0.05) than those for NC diets. An increase in dietary level of multi-enzyme from 0 to 1.0 g/kg resulted in a linear increase (P < 0.05) in AID of Ile by 4.3%, and tended to linearly increase (P < 0.10) AID of Leu, Met, Phe, and Val by a mean of 3.4%. Increasing dietary multi-enzyme from 0 to 1.0 g/kg linearly increased (P < 0.05) AID of total NSP and P by 53.7% and 19.2%, respectively; ATTD of GE by 8.4% and DE and NE values by 8.8% and 8.2%, respectively; tended to linearly increase (P < 0.10) AID of GE by 8.1%. The NE values for NC diet with multi-enzyme at 1.0 g/kg tended to be greater (P < 0.10) than that for PC diet (2,337 vs. 2,222 kcal/kg of DM). In conclusion, multi-enzyme supplementation improved energy and nutrient digestibilities of a corn-SBM-corn DDGS-based diet, implying that the multi-enzyme fed in the current study can be used to enhance energy and nutrient utilization of low-energy AA diets for grower pigs.

Low digestibility of phytate phosphorus, their impacts on the environment, and phytase opportunity in the poultry industry

Phosphorus is an essential macro-mineral nutrient for poultry, needed for the body growth, development of bones, genomic function, good quality flesh, and eggs production. The imbalance of organic phosphorus sources in the diet mostly affect the phosphorus digestibility, reduces the poultry performance and health, and increases the environmental pollution burden. A study was reviewed to estimate the low phytate phosphorus digestibility of ingredients in poultry diet and their impacts on environmental ecosystem and opportunity of phytase supplementation. Plant ingredients mostly used in poultry diets are rich in phytate phosphorus. The phytate phosphorus digestibility and utilization is low in the gut of birds which leads to decrease other nutrients digestibility and increase excessive excretion of phosphorus with additional nutrients in the manure. When that manure applied to the lands containing excessive residual phosphorus and additional nutrients which pollute soil, groundwater disturbed the entire ecosystem. This issue is developed by poultry due to lack of digestive enzyme phytase which promotes the phytate phosphorus during digestion and reduces the excessive losses of phosphorus in excreta. To overcome this matter, the addition of mostly exogenous phospho-hydrolytic phytase enzymes in the diet, i.e. Escherichia coli, Peniophora lycii, Aspergillus niger, and Ficum, are the possible ways to increase the digestibility and utilization of phytate phosphorus and promote the stepwise release of phosphorus from phytate and significantly decrease phosphorus excretion. The aim of this review is to highlight the role of phytase supplementation in the poultry feeding, improvement of phytate phosphorus digestibility with performance, and reduction of phosphorus pollution from the environment.

Growth performance, gastrointestinal weight, microbial metabolites and apparent retention of components in broiler chickens fed up to 11% rice bran in a corn-soybean meal diet without or with a multi-enzyme supplement

We investigated the effects of adding up to 11% rice bran (RB) in corn-soybean meal diets fed to broiler chickens without or with a multi-enzyme supplement (MES). The MES supplied xylanase, β-glucanase, invertase, protease, cellulase, α-amylase and mannanase with targeted activity of 2,500, 300, 700, 10,000, 1,200, 24,000, and 20 U/kg of feed, respectively. The study used a two-phase feeding program (starter, d 0 to 24; finisher, d 25 to 35) with RB added at 5% and 11%, respectively creating 4 diets in each phase. Diets were iso-caloric and iso-nitrogenous and contained phytase (500 FTU/kg) and TiO2 as a digestibility marker. Three hundred and sixty d-old male Ross 708 broiler chicks were placed in cages based on BW (15 birds/cage) and allocated to 4 diets (n = 6). Birds had free access to feed and water. Body weight and feed intake were recorded. Excreta samples were collected 3 d prior to the end of each phase for apparent retention (AR) of components. Samples of birds were sacrificed on d 24 and 35 for gut weight and ceca digesta for organic acid content. There was no interaction (P > 0.10) between RB and MES on BWG and FCR in starter or finisher phase. In finisher phase, birds fed MES had better BWG (961 versus 858 g) and FCR (1.69 versus 1.86) than birds fed non-MES diets (P < 0.01). Feeding RB reduced (P = 0.02) BWG in finisher phase resulting in lower d 35 BW. Birds fed RB had higher (P ≤ 0.01) gizzard weight on d 24 and 35 than non-RB birds. An interaction (P ≤ 0.01) between RB and MES on concentrations of propionic and iso-butyric acids in ceca digesta showed that MES reduced these acids in non-RB diet. The AR of gross energy was higher (P < 0.02) for MES versus non-MES birds in starter and finisher phases. In conclusion, independently, RB increased gizzard weight and reduced final BW whereas MES improved growth and energy utilization.

Combination of phytase and citric acid, but not phytase alone, ensures regular rates of growth and bone mineralization in quails under severe phosphorus restriction

An experiment was conducted to evaluate the effects of phytase (PHY), alone or in combination with citric acid (CA), on growing Japanese quails under moderate and severe phosphorus (P) restriction. For this, 504 one-day-old female quails were distributed in a completely randomised design with seven treatments and six replications. Treatments consisted of the following diets: (a) positive control (PC): formulated according to quails nutritional requirements; (b) negative control 40% (NC₄₀ ): PC with 40% less aP; (c) NC₄₀ +PHY; (d) NC₄₀ +PHY+CA; (e) negative control 65% (NC₆₅ ): PC with 65% less aP; (f) NC₆₅ +PHY; (g) NC₆₅ +PHY+CA. Phytase and CA were included at 300 FTU/kg and 40 g/kg, respectively. Performance, bone mineralization and plasma mineral concentration were evaluated at day 35; calcium (Ca) and P metabolism, between days 36 and 39. No significant differences in performance, plasma Ca and P were detected between quails fed PC or NC₄₀ ; however, NC₄₀ decreased tibia ash (p < 0.01). Treatment NC₆₅ impaired daily weight gain (p = 0.01), tibia ash (p < 0.01), and tibia optical densitometry (p = 0.03), as well as modified plasma Ca (p < 0.01) and P (p = 0.03) concentrations when compared to PC. Both NC₄₀ and NC₆₅ reduced P excretion (p < 0.01). Phytase alone restored tibia ash of NC₄₀ quails to regular rates. Nevertheless, only PHY and CA combined returned plasma P, tibia ash, tibia optical densitometry, and daily weight gain of quails fed NC₆₅ to similar values as those observed in PC. In conclusion, PHY alone suppresses the negative effects of moderate P restriction in growing Japanese quails, but fails in this task under severe P restriction. In such a situation, only the combination of PHY and CA ensures regular rates of growth and bone mineralization. This concept should be better explored by producers in order to take full advantage of the reduction in P excretion achieved by lowering dietary P concentrations.

Effects of dietary 1 alpha-hydroxycholecalciferol in calcium and phosphorous-deficient diets on growth performance, tibia related indices and immune responses in broiler chickens

This experiment was conducted to investigate the effect of dietary 1α-hydroxycholecalciferol (1α-OH-D₃) in calcium (Ca)- and phosphorous (P)-deficient diets on growth performance, carcass characteristics, tibia related parameters, and immune responses of broiler chickens. A total of 280 one-day-old broiler chickens (Ross 308) were assigned to 20 floor pens and 4 dietary treatments with 5 replicates. Dietary treatments consisted of starter diets (starter diet of treatment A: 1% Ca, 0.73% total phosphorus [tP]; starter diet of treatment B: 0.85% Ca, 0.64% tP + 5 μg/kg of 1α-OH-D₃; starter diet of treatment C: 0.85% Ca, 0.59% tP + 5 μg/kg of 1α-OH-D₃; starter diet of treatment D: 0.85% Ca, 0.54% tP + 5 μg/kg of 1α-OH-D₃), grower diets (grower diet of treatment A: 0.86% Ca, 0.68% tP; grower diet of treatment B: 0.73% Ca, 0.59% tP + 5 μg/kg of 1α-OH-D₃; grower diet of treatment C: 0.73% Ca, 0.55% tP + 5 μg/kg of 1α-OH-D₃; grower diet of treatment D: 0.73% Ca, 0.50% tP + 5 μg/kg of 1α-OH-D₃) and finisher diets (finisher diet of treatment A: 0.81% Ca, 0.64% tP; finisher diet of treatment B: 0.68% Ca, 0.56% tP + 5 μg/kg of 1α-OH-D₃; finisher diet of treatment C: 0.68% Ca, 0.52% tP + 5 μg/kg of 1α-OH-D₃; finisher diet of treatment D: 0.68% Ca, 0.48% tP + 5 μg/kg of 1α-OH-D₃). Results showed that body weight gain (BWG) and feed intake (FI) of broilers in treatment B were similar to those of broilers in treatment A at the end of the trial (P < 0.05). Broilers in treatments C and D had lower BWG and FI than those in treatment A during the whole trial (P < 0.05). Feed conversion ratio, carcass traits and relative weight of lymphoid organs were not affected by dietary treatments (P > 0.05). Dietary treatments had no significant effect on antibody titers against Newcastle and Influenza disease viruses as well as sheep red blood cells. Dietary treatments had no significant effects on tibia ash and tibial dyschondroplasia score. Broilers fed Ca-P deficient diets had lower tibia Ca and P than those in treatment A (P < 0.05). In conclusion, results indicated that broilers fed Ca-P deficient diets supplemented with 5 μg/kg 1α-OH-D₃ failed to achieve the same tibia Ca and P values as broilers fed nonphytate phosphorus adequate diets.

Phytase Activity in the Digesta from Different Parts of the Digestive Tract and Ileal Digestibility of Nutrients in Broilers Fed with Buckwheat Diets

In the present study, the effects of dietary buckwheat on phytase activity in the digesta from different parts of the digestive tract, and ileal digestibility of nutrients were determined in broilers fed with buckwheat diets. Eighty male broilers (29-d-old) were divided into four groups (20 birds each), and were fed one of the following diets until they were 36-d-old: positive control (PC) diet formulated based on the NRC recommendations, negative control (NC) diet containing 0.15% lower non-phytate phosphorus (P) than that in the PC diet, and two other diets formulated by replacing corn in NC diet with either 20% non-germinated (BU) or germinated (GBU) buckwheat. At the age of 36 d, broilers were sacrificed to collect digesta from the crop, gizzard, duodenum, jejunum, ileum, and cecum. The activity of phytase was low in the PC and NC diets, which increased in the BU diet and increased further in the GBU diet. A similar trend was observed in the crop digesta; however, the phytase activity in the crop digesta of BU and GBU diets was marginally lower when compared with that in each diet. These values decreased sharply when the digesta moved to the gizzard, and then decreased gradually. The ileal digesta exhibited significantly low activity with negligible effect of dietary treatment. The result of two-way analysis of variance with germination and digestive tract parts as main factors showed that the effect of digestive tract parts and interaction between factors was significant on the phytase activity in digesta. The dietary BU and GBU did not affect the ileal crude protein digestibility; however, it increased the ileal phytate P digestibility. These results suggest that in broilers, the crop might be the primary site of phytate degradation by buckwheat phytase, and the buckwheat might have negligible adverse effect on ileal digestibility of nutrients.

Influence of dietary carbohydrases, individually or in combination with phytase or an acidifier, on performance, gut morphology and microbial population in broiler chickens fed a wheat-based diet

The objective of this study was to examine the effects of dietary carbohydrases (xylanase and β-glucanase; XG), individually or in combination with phytase or acidifier on the growth performance, carcass attributes, intestinal microbial counts and morphology in broiler chickens fed a wheat-based diet. A total of 240 one-day-old male broiler chicks were randomly allocated into 4 treatment groups with 6 replicates of 10 birds each. The dietary treatments included a basal diet, the basal diet with an enzyme complex containing XG, XG plus a microbial phytase (XG + P) and XG plus acidifier (XG + A). The results indicated that feed conversion ratio (FCR) was improved in broiler chickens which received XG + A during the entire production period (1 to 35 d) of the trial (P < 0.05). The broiler chickens fed XG + P had lower feed intake compared with the control group at 29 to 35 d of age. The experimental treatments had no effect on the body weight gain of broiler chickens. In carcass traits, except for spleen (P < 0.05), the dietary treatments had no effects on the carcass characteristics of broiler chickens. The birds which received diets supplemented with XG and XG + A had a lower weight of the spleen compare with the control. Addition of XG in combination with phytase (XG + P) resulted in a decrease in ileal enumeration of Escherichia coli at 35 d of age (P < 0.05). However, dietary treatments did not alter the population of ileal Lactobacilli in broiler chickens. Supplementing carbohydrases with phytase and acidifier (XG + P and XG + A) significantly increased the intestinal villus length at 35 d of age (P < 0.05). In conclusion, the present study demonstrated that supplementation of the wheat-based diet with a combination with carbohydrases and acidifier (XG + A) improves FCR in broiler chickens. Furthermore, combinations of carbohydrases with phytase (XG + P) and with acidifier (XG + A) decrease the E. coli counts and increase the villus length in broiler chickens.

Effect of high-dose phytase and citric acid, alone or in combination, on growth performance of broilers given diets severely limited in available phosphorus

1. Two trials were conducted to evaluate the effect of high-dose phytase alone or in combination with citric acid (CA) in the diet severely limited in available phosphorus (P) on performance, plasma P and plasma Ca of broilers from 22 to 42 d of age. 2. In Trial 1, 297 21-d-old female chicks were placed into 27 pens and allocated to 9 maize-soybean meal-based dietary treatments, which were a positive control [PC, 4.23 g/kg non-phytate P (NPP)] and 8 negative control (NC, 1.35 g/kg NPP) groups consisting of two concentrations of CA (0 and 20 g/kg) and 4 concentrations of phytase (0, 1000, 2000 and 4000 U/kg) in a 2 × 4 factorial arrangement. In Trial 2, 192 21-d-old male chicks were placed into 24 pens and allocated to 6 wheat-canola meal-based dietary treatments, which were a PC (4.2 g/kg NPP), a NC (1.68 g/kg NPP) and 4 NC groups consisting of two concentrations of CA (0 and 20 g/kg) and two concentrations of phytase (2000 and 4000 U/kg) in a 2 × 2 factorial arrangement. 3. In both trials, birds fed on the PC had significantly higher average daily gain (ADG), average daily feed intake (ADFI), plasma P and lower feed conversion ratio (FCR) and plasma Ca than those of birds fed on the NC. CA supplementation significantly increased ADG and ADFI. There was a significant interaction between CA and phytase on plasma P where CA improved the effect of phytase on plasma P. In Trial 1, phytase addition improved ADG, ADFI, FCR and plasma Ca linearly. 4. Briefly, this research showed the interaction effect between CA and phytase on plasma P when broilers were fed on diets based on maize-soybean meal or wheat-canola meal. The results showed that CA supplementation lowered the concentration of phytase that is needed in low NPP diets to increase plasma P.

Net energy content of dry extruded-expelled soybean meal fed with or without enzyme supplementation to growing pigs as determined by indirect calorimetry

Two experiments were conducted to determine the NE content of dry extruded-expelled soybean (DESBM) and the effect of a multienzyme carbohydrase (MC) mixture on the NE content of DESBM and to determine the effect of diet design on NE values in growing pigs using indirect calorimetry (IC). In Exp. 1, 24 barrows (19.6 ± 0.51 kg BW) were allotted in a completely randomized design to 4 dietary treatments: a corn–soybean meal basal diet (Diet A), a diet containing Diet A and DESBM in an 80:20 ratio with a constant CP (Diet B), a diet with an 80:20 ratio of Diet A and DESBM with a constant corn:soybean meal ratio (Diet C), and a diet with simple substitution of Diet A with DESBM in an 80:20 ratio (Diet D). Pigs were fed in metabolism crates for a period of 16 d to determine the DE and ME and thereafter were moved into an indirect calorimeter where O2 consumption and CO2 production were measured to determine heat production and fasting heat production. The NE content of DESBM was calculated (difference method) to be 2,632, 2,548 and 2,540 kcal/kg DM in diets B, C, and D, respectively. Respective values obtained with published prediction equations were 2,624, 2,530 and 2,436 kcal/kg. In Exp. 2, 24 barrows (16.9 ± 0.76 kg BW) were randomly allotted to 1 of 4 treatments. The diets were a corn–soybean meal basal diet and a diet containing the basal diet and DESBM in an 80:20 ratio with a constant corn:soybean meal ratio with or without 2 levels (0.05% and 0.1%) of MC. The experimental procedures were similar to those described in Exp. 1. Enzyme supplementation improved (P < 0.0001) the DE, ME, and NE content of the DESBM. Multienzyme carbohydrase at 0.05% and 0.1% of the diet improved NE values of DESBM by 4.9% and 3.7%, respectively. In conclusion, the NE values of DESBM obtained with the IC method were higher than the values obtained with prediction equations; the disparity was least when diets were formulated with a constant CP level. However, as the difference method was used to determine the NE of ingredient, it is more appropriate to maintain a constant ratio between the ingredients. Also, the NE value of DESBM obtained for diets C and D were not different. Hence, the average NE value of DESBM evaluated was 2,544 kcal/kg DM. Enzyme supplementation improved the NE content of DESBM fed to growing pigs.

Effects of a multi-enzyme complex on growth performance, nutrient utilization and bone mineralization of meat duck

Background

Previous studies with broiler have shown dietary supplementation with multi-enzyme complex containing non-starch polysaccharides (NSP) degrading enzymes and phytase is efficient in releasing phosphorus (P), calcium (Ca), energy and amino acids from corn-soybean meal diets or corn-sorghum diets, hence compensating considerable levels of nutrients in formulation. Notwithstanding, such potentials have not been well defined in duck nutrition. Giving China being the largest duck producing country, we conducted this study to establish adequate specifications of major nutrients along with multi-enzyme complex to meat duck from day-old to slaughter, focusing on performance, utilization of nutrients and bone mineralization. Five dietary treatments were: Positive control (PC,T1 ): the nutrients concentration of diet for 1 to 14 d of age were apparent metabolizable energy(AME) 2,800 kcal/kg, crude protein (CP)19.39%, Ca 0.85%, available phosphorus (avP) 0.42%; for 15 to 35 d of age these parameters were AME 2,900 kcal/kg, CP 16.47%,Ca 0.76%,avP 0.38%; Negative control 1(NC1,T2), the AME and digestible amino acids (DAA) were reduced by 70 kcal/kg and 2.0%, avP and Ca by 1.0 g/kg from PC diet; Negative control 2( NC2,T4), the down-spec from PC diet was AME 100 kcal/kg, DAA 2.5%, avP 1.5 g/kg and Ca 1.2 g/kg; The enzyme complex was added at the same dosage (200 mL/ 1,000 kg) on NC1 (T3) and NC2 (T5) diets.

Results

Comparing with the ducks fed on T1, T3 and T5 diets, the birds fed on NC2 diet showed the lowest (P < 0.05) body weight ( d 14 and 35), feed intake (d 35), tibia ash, Ca and P contents (d 14 and 35), and the utilization of nutrients (P < 0.05). The supplementation with the enzyme complex to the NC diets restored growth rate, utilization of nutrients and bone mineralization to the level of the PC diet, and increased AME by 60 kcal/kg and 117 kcal/kg, respectively for the NC1 and NC2 diets.

Conclusion

These results suggest that down-spec AME by 100 kcal/kg, DAA by 2.5%, avP by 1.5 g/kg and Ca by 1.2 g/kg caused detrimental effects on duck performance compared with those fed on the PC diet, and these performance losses can be compensated by the addition of the multiple-enzyme complex.