Biochemistry of phytate and phytases: Applications in monogastric nutrition

Phytic acid is important for plant germination as the primary store of phosphorus but has become very important in animal nutrition due to the sheer volume of plant feedstuffs that are used in feeding non-ruminant animals. Phytases on the other hand enable the utilisation of the phosphorus that is bound in phytic acid. Animals do not produce phytase in any appreciable amount and hence the phytase primarily used in animal feed are of microbial origin. Biochemical studies have provided insights into the role of this vital compound, and have enabled development of a spectrum of enzymes that are capable of tolerating the heat treatment of some animal feed, escape the denaturing action of the gastric HCl and the digestive action of both gastric and intestinal proteases. In spite of the progress in understanding of phytic acid and phytase in monogastric animals, much still need to be learnt. A better understanding of the action of phytic acid in the digestive tract of animals is still needed and newer generation of phytases that allowed greater reduction in the use of inorganic phosphorus are continually being discovered and developed. The future of animal feeding will continue to require a better understanding of the biochemical principles underpinning nutrient utilisation by animals

The effect of carbohydrases or prebiotic oligosaccharides on growth performance, nutrient utilisation and the development of the small intestine and immune organs in broilers fed nutrient-adequate diets based on either wheat or barley

BACKGROUND: Non‐starch polysaccharides are large complex molecules and are found in cereal grains. This study was conducted to investigate the effect of carbohydrase enzymes or prebiotic oligosaccharides on growth performance, nutrient utilisation and weight of organs associated with the immune system in broilers fed wheat‐ or barley‐based diets. RESULTS: In wheat‐based diets, feed intake was lower (P < 0.05) following xylo‐oligosaccharide supplementation, whereas in barley‐based diets feed intake was greater (P < 0.05) following β‐glucanase supplementation. Gross energy digestibility was improved (P < 0.01) when either level of xylanase was added to wheat diets. Ileal digestible energy was greater (P < 0.01) in wheat diets including an additive compared with the control diet. In wheat diets, bursa weight was lower (P < 0.05) following xylo‐oligosaccharide supplementation compared with the control treatment. CONCLUSIONS: The current study showed that supplemented carbohydrases or prebiotic oligosaccharides could alter the development of immune organs or small intestine without any significant effect on growth performance in broilers receiving nutrient‐adequate diets

The similarity of the effect of carbohydrase or prebiotic supplementation in broilers aged 21 days, fed mixed cereal diets and challenged with coccidiosis infection

The aim of this study was to investigate the effect on growth performance and nutrient utilisation when supplementing diets deficient in energy and protein with carbohydrase enzymes or xylo-oligosaccharide in broilers challenged with coccidia. 960 Ross 308 broilers were used in this 21-day study. The treatments were arranged into a 2×4 factorial with 2 challenge states (challenged and non-challenged) and 4 different additive types (control, xylanase alone, xylanase and β-glucanase mixture and xylo-oligosaccharide). On day 14, the challenged group received 12× the recommended dose of coccidiosis vaccine while the non-challenged group received a sham treatment of water only. The birds and feed were weighed on days 0, 14 and 21. On day 21, two birds per pen were euthanized, the caeca were removed and the contents collected for short chain fatty acid analysis. Six more birds per pen were euthanized and ileal digesta were collected and pooled per pen for nutrient digestibility analysis. Feed intake was greater (P < 0.05) on days 14 and 21 when xylo-oligosaccharide was included in the diet compared to the xylanase and β-glucanase mixture in birds challenged with coccidiosis. Including xylo-oligosaccharide in the diet improved (P < 0.05) the digestibility of nitrogen and supplementing diets with the xylanase and β-glucanase mixture improved (P < 0.05) the digestibility of several amino acids. The concentration of arabinose and xylose was (P < 0.001) greater when broiler diets were supplemented with carbohydrase enzymes or xylo-oligosaccharide compared to the control. Although there was an increase in short chain fatty acid production due to the addition of carbohydrase enzymes or xylo-oligosaccharide, there was no additive effect on the %G+C profile of caecal bacteria however there was a negative effect of coccidiosis. In conclusion, the similarity in the response to carbohydrase enzymes or xylo-oligosaccharide supplementation illustrates that the hydrolysis products from carbohydrase activity may have prebiotic like effects

Biochemistry of phytate and phytases: Applications in monogastric nutrition

Phytic acid is important for plant germination as the primary store of phosphorus but has become very important in animal nutrition due to the sheer volume of plant feedstuffs that are used in feeding non-ruminant animals. Phytases on the other hand enable the utilisation of the phosphorus that is bound in phytic acid. Animals do not produce phytase in any appreciable amount and hence the phytase primarily used in animal feed are of microbial origin. Biochemical studies have provided insights into the role of this vital compound, and have enabled development of a spectrum of enzymes that are capable of tolerating the heat treatment of some animal feed, escape the denaturing action of the gastric HCl and the digestive action of both gastric and intestinal proteases. In spite of the progress in understanding of phytic acid and phytase in monogastric animals, much still need to be learnt. A better understanding of the action of phytic acid in the digestive tract of animals is still needed and newer generation of phytases that allowed greater reduction in the use of inorganic phosphorus are continually being discovered and developed. The future of animal feeding will continue to require a better understanding of the biochemical principles underpinning nutrient utilisation by animals

Whole Body Nutrient Accretion, Growth Performance and Total Tract Nutrient Retention Responses of Broilers to Supplementation of Xylanase and Phytase Individually or in Combination in Wheat-Soybean Meal Based Diets

Growth performance, total tract nutrient retention and whole body nutrient accretion rates responses of broilers to supplementation of enzymes containing phytase or xylanase activities were investigated using 300 broilers. At day old, 280 broilers were assigned to 5 dietary treatments which were: 1) positive control (PC) diet which met NRC (1994) nutrient requirement for broilers, 2) negative control (NC) diet which was marginally deficient in phosphorus and ME, 3) NC plus phytase added at 1,000FTU/kg, 4) NC plus xylanase added at 4,000U/kg and, 5) NC plus phytase and xylanase added at 1,000 and 4,000units/kg, respectively. Each treatment had 8 replicate cages with 7 birds per replicate cage. Comparative slaughter technique was used for determination of whole-body nutrient accretion rate. Twenty broilers with the same initial body weight as the 280 broiler chicks used in the growth trial made up the initial slaughter group killed at day 0. A final slaughter group of 40 birds, one bird from each cage, were slaughtered on day 21. The birds selected were those with body weight closest to the average body weight of the birds in each replicate cage. Phytase alone or combined with xylanase improved weight gain and bone ash (P<0.05). Phytase alone improved (P<0.5) total tract P retention and ME, phytase and xylanase combined improved (P<0.01) total tract dry matter and ME. Phytase alone improved (P<0.5) whole body daily accretion rates of dry matter, protein, fat, P, and Ca in comparison to NC treatment. Overall, phytase in wheat-based diet improved growth performance and whole body accretion of minerals and protein, the improvement in protein accretion is an indication of improvement in nutrient utilization resulting from phytase use

Metabolizable Energy Content of Meat and Bone Meal in Corn-Soybean Meal or Corn, Wheat and Soybean Meal Diets for Broilers

The experiment was conducted to determine the apparent metabolizable energy (AME) or nitrogen-corrected metabolizable energy (AMEn) content of a high protein meat and bone meal (MBM) in broiler diets contain graded levels of wheat. Two hundred eighty-eight 14-d old broilers were allocated to six dietary treatments in a randomized complete block design and a2×3 factorial arrangement of treatments namely two levels of MBM (0 and 80g/kg) and three levels of wheat (0, 100 and 200g/kg). Wheat replaced part of corn and soybean meal and MBM was added at 0 or 80g/kg at each level of wheat. The birds received the diets for 7 d, and excreta were collected on d 19 to 21. The substitution of corn and SBM by wheat (200g/kg) increased the total NSP content in the diet by 11g/kg. There was a 5% decrease in both AME and AMEn when the level of wheat in the corn-SBM was increased to 200g/kg but this decrease was not significant. On the average, irrespective of wheat levels, AME and AMEn of the MBM were 2,734 and 2,586kcal/kg, respectively. Dietary AME and AMEn were greater in the diets with 200g/kg wheat compared to corn-SBM diet (P<0.05), and N excretion was greater (P<0.01) in the diets with MBM. Our results suggest that replacing part of corn and soybean meal with up to 200g/kg of wheat similar to what was used in the current study would have no effect on metabolizable energy of MBM

Ileal mineral digestibility and expression of nutrient transporter genes of broiler chickens in response to variable dietary total Ca and phytase supplementation are influenced by time on experimental diet and age of the birds

ABSTRACT: Two experiments were conducted to determine the impact of Ca, phytase, sampling time, and age on the digestibility (AID) of Ca and P and the expression of their transporters. Cobb 500 male chicks (N = 600) were used in each experiment and allocated to cages with 10 (Exp 1, 8–11 d) or 5 (Exp 2, 21–24 d) birds/cage and 10 (Exp 1) or 20 (Exp 2) reps/treatment. Treatments were a 2 × 3 factorial arrangement, with low (LOW) or standard (STD) Ca level and 3 phytase (PHY) levels (0, 300, or 3,000 FYT/kg). Ileal digesta were collected at 8, 12, 24, 48, and 72 h, and jejunum tissues at 12, 48, and 72 h after the start of feeding experimental diets. In Exp 1, there was no effect of Ca or phytase on the AID of Ca at 8, 12, or 24 h. Phytase increased the AID of P (P < 0.05) at all time points, and the magnitude was influenced by Ca. At 12 h, the mRNA level of P (NaPi-IIb) and Ca (CaSR) transporters was greatest in the LOW diets without phytase (Ca × PHY, P ≤ 0.06). In Exp 2, the STD diet decreased the AID of Ca and P (P < 0.05) at 8, 24, 48, or 72 h. Phytase increased the AID of Ca (P < 0.05) at 8, 12, and 24 h, and decreased the AID of Ca (quadratic, P < 0.05) in the STD diet (48 h). The AID of P (P < 0.05) increased with phytase at all sampling times. At 48 h, 3,000 FYT/kg decreased (P < 0.05) mRNA expression of NaPi-IIb and Ca transporter ATP2B1 in the STD diet (Ca × PHY, P < 0.05). In conclusion, to avoid adaptation of broilers to Ca and P deficiencies, the optimal time on experimental diets is ≤ 48 h for young broilers and ≤ 24 h in older birds due to up- or down-regulation of Ca and P transporters in response to dietary Ca, P, and phytase

Effects of xylanase, protease, and xylo-oligosaccharides on growth performance, nutrient utilization, short chain fatty acids, and microbiota in Eimeria-challenged broiler chickens fed high fiber diet

A 21-d experiment was conducted to study the effect of xylanase, protease, and xylo-oligosaccharides on growth performance, nutrient utilization, gene expression of nutrient transporters, cecal short-chain fatty acids (SCFA), and cecal microbiota profile of broilers challenged with mixed Eimeria spp. The study utilized 392 zero-d-old male broiler chicks allocated to 8 treatments in a 4 × 2 factorial arrangement, as follows: corn-soybean meal diet with no enzyme (Con); Con plus xylanase alone (XYL); Con plus xylanase combined with protease (XYL + PRO); or Con plus xylo-oligosaccharides (XOS); with or without Eimeria challenge. Diets were based on a high-fiber (100 g/kg soluble fibers and 14 g/kg insoluble fibers) basal diet. At d 15, birds in challenged treatment were gavaged with a solution containing Eimeria maxima, Eimeria acervulina, and Eimeria tenella oocysts. At d 21, birds were sampled. Eimeria depressed (P < 0.01) growth performance and nutrient utilization, whereas supplementation had no effect. There were significant Eimeria × supplementation interactions for the sugar transporters GLUT5 (P = 0.02), SGLT1 (P = 0.01), SGLT4 (P < 0.01), and peptide transporter PepT1 (P < 0.01) in jejunal mucosa. Eimeria challenge increased the expression of GM-CSF2 (P < 0.01) and IL-17 (P = 0.04) but decreased (P = 0.03) IL-1β expression in the cecal tonsil. Eimeria × supplementation interactions for cecal acetate, butyrate, and total SCFA showed that concentrations increased or tended to be greater in the supplemented treatments, but only in non-challenged birds. Birds challenged with Eimeria spp. had higher concentrations of isobutyrate (P < 0.01), isovalerate (P < 0.01), and valerate (P = 0.02) in cecal content. Eimeria challenge significantly (P < 0.01) decreased the microbial richness and diversity, and increased (P < 0.01) the proportion of Anaerostipes butyraticus, Bifidobacterium pseudolongum, and Lactobacillus pontis. In conclusion, Eimeria infection depressed growth performance, nutrient utilization with regulating nutrient transporters. Furthermore, Eimeria challenge shifted the microbial profile and reduced microbial richness and diversity. On the other hand, enzyme supplementation showed limited benefits, which included increased concentrations of SCFA