Efficacy of supplementation of a phytase-producing bacterial culture on the performance and nutrient use of broiler chickens fed corn-soybean meal diets

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.

Alternatives to antibiotics for organic poultry production: types, modes of action and impacts on bird's health and production

The poultry industry contributes significantly to bridging the nutritional gap in many countries because of its meat and eggs products rich in protein and valuable nutrients at a cost less than other animal meat sources. The natural antibiotics alternatives including probiotics, prebiotics, symbiotics, organic acids, essential oils, enzymes, immunostimulants, and phytogenic (phytobiotic) including herbs, botanicals, essential oils, and oleoresins are the most common feed additives that acquire popularity in poultry industry following the ban of antibiotic growth promoters (AGPs). They are commonly used worldwide because of their unique properties and positive impact on poultry production. They can be easily mixed with other feed ingredients, have no tissue residues, improve feed intake, feed gain, feed conversion rate, improve bird immunity, improve digestion, increase nutrients availability as well as absorbability, have antimicrobial effects, do not affect carcass characters, decrease the usage of antibiotics, acts as antioxidants, anti-inflammatory, compete for stress factors and provide healthy organic products for human consumption. Therefore, the current review focuses on a comprehensive description of different natural antibiotic growth promoters’ alternatives, the mode of their action, and their impacts on poultry production.

Probiotics Treatment of Leg Diseases in Broiler Chickens: a Review

Normal development and growth of bones are critical for poultry. With the rapid growth experienced by broiler chickens, higher incidences of leg weakness and lameness are common problems in adolescent meat-type poultry that present huge economic and welfare issues. Leg disorders such as angular bone deformities and tibial dyschondroplasia have become common in broilers and are associated with poor growth, high mortality rates, increased carcass condemnation, and downgrading at slaughter. Probiotics have shown promise for a variety of health purposes, including preventing diarrhea, elevating carcass quality, and promoting growth of the poultry. In addition, recent studies have indicated that probiotics can maintain the homeostasis of the gut microbiota and improve the health of the gastrointestinal tract, which confers a potentially beneficial effect on bone health. This review mainly describes the occurrence of broiler leg disease and the role of probiotics in bone health through regulating the gut microbiota and improving intestinal function, thus providing a relevant theoretical basis for probiotics to hinder the development of skeletal disorders in broiler chickens.

Impact of Ag Nanoparticles (AgNPs) and Multimicrobial Preparation (EM) on the Carcass, Mineral, and Fatty Acid Composition of Cornu aspersum aspersum Snails

The hygienic practices on farms should reduce pathogenic microorganisms while simultaneously not harming the animals themselves; they must also not degrade the products' quality. We assessed the effect of covering feed tables with paint containing silver nanoparticles (AgNPs) and the periodic spraying of effective microorganisms (EM) on production indicators and basic chemical composition, mineral content and fatty acid profiles in the bodies of Cornu aspersum aspersum snails. The animals were divided into four groups: (1) control, (2) with feed tables covered with AgNPs paint, (3) with EM spray applied and (4) with both factors-AgNP paint and EM spray. The highest increase in Ag, Zn, Fe and Ca retention, and the remodelling of the fatty acid profile in the carcasses of snails was found to be in the group of animals in contact with the feed tables covered with AgNP paint. In the group of animals exposed to the action of EM, an increased retention of Fe, Cu, P, Mg and Zn was found.

Microbial Ecology of the Western Gull (Larus occidentalis)

Avian species host diverse communities of microorganisms which have important roles in the life of birds, including increased metabolism, protection from disease, and immune system development. Along with high human populations and a diversity of human uses of coastal zones, anthropogenic food sources are becoming increasingly available to some species, including gulls. Anthropogenic associations increase the likelihood of encountering foreign or pathogenic bacteria. Diseases in birds caused by bacteria are a substantial source of avian mortality; therefore, it is essential to characterize the microbiome of seabirds. Here, we determined both core and environmentally derived microbial communities of breeding western gulls (Larus occidentalis) from six colonies in California and Oregon. Using DNA extracted from bacterial swabs of the bill, cloaca, and feet of gulls, 16S rRNA gene sequencing was performed targeting the V4 region. We identified a total of 8542 operational taxonomic units (OTUs) from 75 gulls. Sixty-eight OTUs were identified in gulls from all six colonies with the greatest representation from phyla's of Firmicutes, Proteobacteria, Bacteroidetes, and Actinobacteria. Overall, microbial richness based on Chao's Abundance-based Coverage Estimator (ACE) index was similar for all colonies (mean = 2347 OTUs) with the smallest coastal colonies having the highest richness (mean = 2626 OTUs) and the largest colonies, located farther off-shore, having the lowest (mean = 2068 OTUs). This survey represents the most in-depth assessment to date of microbes associated with western gulls, and the first study to identify both species-specific and environmentally derived bacteria across multiple populations.

Effects of supplementing freeze-dried Mitsuokella jalaludinii phytase on the growth performance and gut microbial diversity of broiler chickens

Inclusion of phytase in animal feedstuff is a common practice to enhance nutrients availability. However, little is known about the effects of phytase supplementation on the microbial ecology of the gastrointestinal tract. In this study, freeze-dried Mitsuokella jalaludinii phytase (MJ) was evaluated in a feeding trial with broilers fed a low available phosphorus (aP) diet. A total of 180 male broiler chicks (day-old Cobb) were assigned into three dietary treatments: Control fed with 0.4% (w/w) of available phosphorus (aP); Group T1 fed low aP [0.2% (w/w)] supplemented with MJ; and T2 fed low aP and deactivated MJ. The source of readily available P, dicalcium phosphate (DCP), was removed from low aP diet, whereby additional limestone was provided to replace the amount of Ca normally found in DCP. For each treatment, 4 replicate pens were used, where each pen consisted of 15 animals. The animals' energy intake and caecal bacterial community were monitored weekly for up to 3 weeks. The apparent metabolizable energy (AME) and apparent digestibility of dry matter (ADDM) of broilers fed with different diets were determined. In addition, the caecal microbial diversities of broilers were assessed using high-throughput next-generation sequencing targeting the V3-V4 region of bacterial 16S rRNA. The results showed that broilers fed with T1 diet have better feed conversion ratio (FCR) when compared to the Control (p < .05) and T2 diets (p < .05), demonstrating the efficiency of MJ as a supplement to low aP diet. Nevertheless, MJ did not significantly affect the microbial population and diversity in broilers' caeca, which mainly consists of members from Bacteroidetes, Firmicutes, and Proteobacteria. Regardless, significant variations in the caecal bacterial composition were observed over time, probably due to succession as the broilers aged. This is the first reported study on the effect of MJ on the microbial diversity of broiler's caeca.

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.

Estimation of standardized mineral availabilities in feedstuffs for broilers

Two experiments were conducted to estimate standardized mineral (Ca, P, Cu, Fe, Mn, and Zn) availabilities (SMA) in commonly used feedstuffs and verify the additivity of SMA for diet formulation of broilers. In Exp. 1, after 3 d of acclimation, a total of 96 22-d-old Arbor Acres male broilers were fasted for 24 h. Then the broilers were fed a mineral-free, corn, soybean meal (SBM), or corn-soybean meal (C-SBM) diet for 4 h and the excreta samples were collected for 48 h after feed withdrawal (totally 52 h). The results showed that the endogenous losses of Ca, P, Cu, Fe, Mn, and Zn for chickens fed the mineral-free diet were 13.7, 113, 0.064, 0.593, 0.094, and 0.132 mg/52 h per bird, respectively. The standardized availability values of Ca, P, Cu, Fe, Mn, and Zn were 20.8%, 39.6%, 37.8%, 47.4%, 10.7%, and 45.2% in corn as well as 54.3%, 51.1%, 39.7%, 27.6%, 26.1%, and 51.0% in SBM, respectively. The determined values of SMA in C-SBM diet were close (P > 0.09) to the predicted summations of SMA from corn and SBM (Ca, 48.6% vs. 48.1%; P, 44.9% vs. 46.0%; Cu, 41.7% vs. 39.1%; Fe, 35.3% vs. 33.2%; Mn, 22.7% vs. 22.2%; Zn, 46.2% vs. 48.4%). In Exp. 2, a total of 144 22-d-old Arbor Acres male broilers were used to estimate the SMA values in 6 feedstuffs by using the above procedure. The results showed that the standardized availability values in wheat, wheat bran, corn distillers dried grains with solubles, cottonseed meal, rapeseed meal, and corn gluten meal diets were 24.7% to 55.8% for Ca, 35.6% to 46.6% for P, 24.5% to 45.7% for Cu, 21.6% to 43.5% for Fe, 9.3% to 34.5% for Mn, and 22.9% to 52.9% for Zn, respectively. The results from the present study indicated that the mineral-free diet could be used for estimating the endogenous losses of the above minerals and SMA values of feedstuffs for broilers, and the estimates of SMA in feedstuffs for the C-SBM diet formulation were additive.

Probiotics: A Promising Tool for Calcium Absorption

As we know nutrients are necessary for the development and proper functioning of the human organism. Bioavailabilities of nutrients are the major concern rather than the supply of an adequate amount of nutrients in the diet. Many of the researches have been shown that the consumption of probiotics along with dairy foods buffers the acidity of the stomach and increases the bacterial survival rate into the intestine. A dairy product with probiotics also provides many of essential nutrients, including protein and calcium. From all the necessary nutrients the calcium having a major role in the human body including the development of bone and teeth are also regulating enzymes and many more. Calcium is the most essential nutrient, about 99% of calcium found in teeth and bone in the body and only 1% is found in serum. A numbers of researches have shown that adequate amount of calcium intake leads to reduce risk of fracture, Osteoporosis and Hypoglycaemia and diabetes in some population. Many of the researches suggested that the Probiotics having a significant role in improvement of calcium uptake and absorption, hence the present review gives information about the relationship of probiotics and calcium, ensuring higher bioavailability of calcium and promising a better bone health. Here, the review study showed a significant role of probiotics in calcium absorption and thus the bioavailabilities. Moreover, it is focused on glimpse of various studies and in-vitro models associated with the phenomena of calcium absorption and uptake.

Dose-dependent effects of probiotic supplementation on bone characteristics and mineralisation in meat-type female turkeys

To evaluate the influence of the probiotic on bone tissue in female turkeys, bone mineral density and geometrical and mechanical properties of the tibia and femur were determined in a dose-dependent manner (107 colony-forming units (cfu)/g, 108 cfu/g, 109 cfu/g). No effect of the treatments on bone mass and wall thickness of femur was observed, but the administration of the probiotic resulted in the elongation and the reduction of both strengths. The increase in the cross-sectional area of the femur was dose-dependent. Probiotic supplementation at a concentration of 108 cfu/g resulted in a reduction in ultimate strength, but at a concentration of 107 cfu/g, it resulted in the enhancement of the maximum elastic strength of the tibia compared with other groups. The influence of the probiotic administration on tibia geometry was dose-dependent. No effect of the treatments on the relative bone weight and the ratio of mass to length was observed. In general, the influence of the probiotic administration on bone mineral density, bone mineral concentration, bone tissue density, and bone ash, calcium and phosphorus concentrations was dose-dependent. The investigated properties of long bones in female turkeys are affected through probiotic-supplemented diets in a dose-dependent manner. However, on the basis of densitometry, it seems that the administration of the probiotic at a higher concentration of cells is more beneficial for bone development in turkeys.

Gut microbiota-bone axis

The gut microbiota (GM) is an important regulator of body homeostasis, including intestinal and extra-intestinal effects. This review focuses on the GM-bone axis, which we define as the effect of the gut-associated microbial community or the molecules they synthesize, on bone health. While research in this field is limited, findings from preclinical studies support that gut microbes positively impact bone mineral density and strength parameters. Moreover, administration of beneficial bacteria (probiotics) in preclinical models has demonstrated higher bone mineralization and greater bone strength. The preferential bacterial genus that has shown these beneficial effects in bone is Lactobacillus and thus lactobacilli are among the best candidates for future clinical intervention trials. However, their effectiveness is dependent on stage of development, as early life constitutes an important time for impacting bone health, perhaps via modulation of the GM. In addition, sex-specific difference also impacts the efficacy of the probiotics. Although auspicious, many questions regarding the GM-bone axis require consideration of potential mechanisms; sex-specific efficacy; effective dose of probiotics; and timing and duration of treatment.

Prebiotic and Probiotic Regulation of Bone Health: Role of the Intestine and its Microbiome

Recent advances in our understanding of how the intestinal microbiome contributes to health and disease have generated great interest in developing strategies for modulating the abundance of microbes and/or their activity to improve overall human health and prevent pathologies such as osteoporosis. Bone is an organ that the gut has long been known to regulate through absorption of calcium, the key bone mineral. However, it is clear that modulation of the gut and its microbiome can affect bone density and strength in a variety of animal models (zebrafish, rodents, chicken) and humans. This is demonstrated in studies ablating the microbiome through antibiotic treatment or using germ-free mouse conditions as well as in studies modulating the microbiome activity and composition through prebiotic and/or probiotic treatment. This review will discuss recent developments in this new and exciting area.

Selection, characterisation and evaluation of potential probiotic Lactobacillus spp. isolated from poultry droppings

Aim of the present study was to characterise and evaluate probiotic potential of lactobacilli isolated from indigenous poultry. Lactobacilli were isolated from poultry droppings and identified by genus specific polymerase chain reaction and 16S rRNA gene sequencing. Isolates were characterised in vitro by their ability to tolerate low pH and bile salts, phytase activity, antimicrobial activity, antibiotic susceptibility profile, and autoaggregation and coaggregation with poultry gut pathogens. In vivo evaluation of selected isolates was done by their effect on the body weight gain and immune response of broiler chicks. Total of 90, one-day old chicks, were randomly divided in 9 groups and given selected lactobacilli alone and in combinations (10⁸ cfu/bird, daily) from day 7 to day 35. Body weight gain and humoral immune response to New Castle Disease Virus (NDV) vaccine were determined weekly. Three lactobacilli isolates (SMP52, SMP64 and SMP70) were selected as potentially probiotic bacteria on the basis of in vitro characterisation and identified as Lactobacillus crispatus, Lactobacillus casei and L. crispatus, respectively. Chicks supplemented with 'SMP52', 'SMP64', 'SMP70' and 'SMP64+SMP70' and a commercial probiotic product (Protexin) showed significantly higher mean weight gain per bird (1,584±35.2, 1,629±30.6, 1,668±34.7, 1,619±29.5 and 1,576±31.7 g/bird, respectively) as compared to negative control group (1,394±26.7 g/bird), on day 35. SMP 70 also showed significantly higher geometric mean titre against NDV vaccine at day 21 as compared to negative control. It is concluded that L. crispatus SMP52, L. casei SMP64 and L. crispatus SMP70 are potential probiotic candidates which alone or in different combinations may increase body weight of broilers.

Reduction of Phosphorus Pollution from Broilers Waste through Supplementation of Wheat Based Broilers Feed with Phytase

The present study was conducted to reduce phosphorus pollution from broilers waste by supplementing phytase enzyme in broilers fee. Two hundred two-week-old broilers (Hubbard) were selected and randomly allocated to three dietary treatment groups, one control group (without phytase) and two trial groups (group A with 300 U/kg phytase and group B with 600 U/kg phytase). Each group was composed of 5 replicates with 10 chicks. Broilers fed the control diet (without phytase) gained weight slower (P< 0.05) than the other treatment groups. A significant increase in body weight gain of group A (28.00 ± 2.97) and group B (29.75 ± 3.45) was observed as compared to control group (26.75 ± 2.78). The feed intake of the birds fed the diets containing microbial phytase 600 U/kg was the highest. Phytase significantly (P> 0.05) reduces excreta P and Ca level. Phytase addition did not affect excreta pH. The presence of phytase in feed mixtures significantly (P> 0.05) improves the body weight gain and feed intake of broiler chickens.

Effect of probiotics supplementation on bone mineral content and bone mass density

A few studies in animals and a study in humans showed a positive effect of probiotic on bone metabolism and bone mass density. Most of the investigated bacteria were Lactobacillus and Bifidobacterium . The positive results of the probiotics were supported by the high content of dietary calcium and the high amounts of supplemented probiotics. Some of the principal mechanisms include (1) increasing mineral solubility due to production of short chain fatty acids; (2) producing phytase enzyme by bacteria to overcome the effect of mineral depressed by phytate; (3) reducing intestinal inflammation followed by increasing bone mass density; (4) hydrolysing glycoside bond food in the intestines by Lactobacillus and Bifidobacteria. These mechanisms lead to increase bioavailability of the minerals. In conclusion, probiotics showed potential effects on bone metabolism through different mechanisms with outstanding results in the animal model. The results also showed that postmenopausal women who suffered from low bone mass density are potential targets to consume probiotics for increasing mineral bioavailability including calcium and consequently increasing bone mass density.

Effect of rice polishing and phytase supplementation in diets on productive behavior of broilers

The addition of rice polishing (RP) and phytase enzyme to poultry diets was tested on 200 1-day-old broilers weighing 42 g. Birds were assigned to a completely random design with a 2 × 2 factorial arrangement with four treatments and five repetitions of ten birds each. The factors evaluated were RP level (0 and 15%) and phytase (0 and 150 g/ton). The trial was divided in two phases of 21 days each (42 days total). In phase 1, no treatment effects were observed (P>0.10) on poultry productive behavior. In the second phase (21 to 42 days) and on the total trial (1 to 42 days), there were no effects of the treatments on weight gain or feed intake (P>0.10). Feed conversion was affected by RP (P<0.01) but not by phytase addition (P>0.10). In conclusion, phytase did not affect broiler production with or without RP. Addition of 15 % RP in poultry diets represents an alternative to reduce feed costs.

Development of a procedure to determine standardized mineral availabilities in soybean meal for broiler chicks

The objective of this study was to develop a procedure for estimating the standardized mineral (calcium, Ca; phosphorus, P; copper, Cu; manganese, Mn; zinc, Zn) availabilities (SMA) in soybean meal for broilers. In experiment 1, twelve 24-day-old male chicks were used to determine the length of the pre-experimental fasting period needed to empty the total tract of feed residues. Feed was removed and excreta samples were collected for 12, 24, 36 or 48 h after feed withdrawal, respectively. The result indicated that birds were fasted for at least 24 h after feed withdrawal in order to ensure that no previous feed residues remained in the digestive tract of chicks. In a subsequent experiment, forty-eight 24-day-old male chicks were used to determine SMA in soybean meal. Chicks were fasted for 24 h and then fed mineral-free or soybean meal diet for 4 h, and excreta samples were collected until 24 or 48 h after feed withdrawal. The results showed that the extended excreta collection time of 48 h after feed withdrawal was adequate for estimating SMA. The standardized availability values of Ca, P, Cu, Mn or Zn in soybean meal were 51.14%, 50.22%, 36.28%, 30.79% or 49.66%, respectively. In experiment 3, a similar bioassay was conducted with forty-eight 36-day-old male chicks to measure SMA in the same soybean meal. The standardized availability values of P (51.59%), Cu (36.37%), Mn (31.94%) or Zn (43.37%) were similar (P > 0.12) to the results of experiment 2 except for Ca (41.49%), indicating that the age of birds had no effect on the standardized availabilities of P, Cu, Mn or Zn in soybean meal. The results from this study suggested that this simple and rapid procedure could be used to determine SMA in feedstuffs (e.g., soybean meal) for broiler chicks.

Mitsuokella jalaludinii inhibits growth of Salmonella enterica serovar Typhimurium

Salmonella continues to be a significant human health threat, and the objective of this study was to identify microorganisms with the potential to improve porcine food-safety through their antagonism of Salmonella. Anaerobic culture supernatants of 973 bacterial isolates from the gastrointestinal tract and feces of swine were screened for their capacity to inhibit the growth of Salmonella enterica serovar Typhimurium. Growth inhibition of 1000-fold or greater was observed from 16 isolates, and 16S rRNA sequencing identified the isolates as members of the genera Mitsuokella, Escherichia/Shigella, Anaerovibrio, Selenomonas, and Streptococcus. Four isolates were identified as Mitsuokella jalaludinii, and the mechanism of Salmonella Typhimurium growth inhibition by M. jalaludinii was further investigated. M. jalaludinii stationary phase culture supernatants were observed to significantly inhibit growth, and featured the production of lactic, succinic, and acetic acids. Aerobic and anaerobic S. Typhimurium growth was restored when the pH of the culture supernatants (pH 4.6) was increased to pH 6.8. However, S. Typhimurium growth in fermentation acid-free media was the same at pH 4.6 and pH 6.8 - indicating a synergistic effect between fermentation acid production and low pH as the cause of S. Typhimurium growth inhibition. Furthermore, exposure of S. Typhimurium to M. jalaludinii culture supernatants inhibited Salmonella invasion of HEp-2 cells by 10-fold. The results identify M. jalaludinii as a possible inhibitor of Salmonella growth and invasion in swine, and thus a potential probiotic capable of improving food safety.

Effects of freeze-dried Mitsuokella jalaludinii culture and Natuphos(®) phytase supplementation on the performance and nutrient utilisation of broiler chickens

BACKGROUND

Phytate-bound phosphorus (P) in poultry diets is poorly available to chickens. Hence exogenous phytase is often added to their diets. Mitsuokella jalaludinii is a rumen bacterial species that produces high phytase activity. In this study the effects of freeze-dried active M. jalaludinii culture (FD-AMJC) and Natuphos(®) phytase (phytase N) supplementations on the growth performance and nutrient utilisation of broiler chickens fed a low-available P (aP) diet were evaluated.

RESULTS

Supplementation of FD-AMJC or phytase N to the low-aP diet improved the feed intake, feed conversion rate, body weight gain, dry matter (DM) digestibility and P, Ca and Mn retention, increased the tibia bone ash content, Ca and P concentrations in tibia DM and P and Zn concentrations in plasma and reduced the P excretion of broiler chickens. However, the feed conversion rate, P and Ca retention, DM digestibility and reduction of P excretion were better with FD-AMJC than phytase N supplementation. Supplementation of FD-AMJC to the low-aP diet also improved the apparent metabolisable energy value of the diet, Cu and Zn retention and crude protein digestibility, but phytase N supplementation did not.

CONCLUSION

FD-AMJC supplementation was more efficient in improving nutrient utilisation and reducing P excretion in chickens than phytase N supplementation.

Non-phytate phosphorus requirements and efficacy of a genetically engineered yeast phytase in male Lingnan Yellow broilers from 1 to 21 days of age

This experiment was conducted to investigate the requirement of non-phytate phosphorus (nPP) and efficacy of a genetically engineered yeast phytase in performance and tibia characteristics by male Lingnan Yellow broilers from 1 to 21 days of age. A total of 2640 1-day-old male chicks were randomly allotted to one of 11 dietary treatments, which consisted of six replicate floor pens with 40 birds per pen. All treatments had the same levels of all nutrients except for phosphorus and phytase. The control group (treatment 1) was fed the basal diet without dicalcium phosphate or phytase supplementation. Dietary concentrations of nPP were 0.11%, 0.19%, 0.27%, 0.35%, 0.43%, 0.51% and 0.59% respectively for treatments 1, 2, 3, 4, 5, 6 and 7, through addition of dicalcium phosphate (chemistry grade) to the basal diet. Diets 8-11 were supplemented with a genetically engineered yeast phytase 250, 500, 750 U/kg and a commercial phytase product 500 U/kg in basal diet respectively. The results showed that 0.46% and 0.51% nPP were required for maximum body-weight gain and optimum tibia development indicators respectively. However, 0.59% nPP had a negative effect on bird growth. The equivalency value of the genetically engineered yeast phytase was estimated to be 874 U/kg to liberate 0.1% nPP.

Utilização de nutrientes em frangos alimentados com dietas suplementadas com fitase e níveis reduzidos de fósforo não-fítico

Avaliaram-se a digestibilidade ileal, retenção de nutrientes e valores de energia metabolizável aparente (EMA) de dietas suplementadas com fitase e níveis reduzidos de fósforo não-fítico (FNF) para frangos de corte. Foram utilizados 330 pintos machos em delineamento em blocos ao acaso e esquema fatorial 2 x 3 com dois níveis de fitase (0 e 25U/kg) e três níveis de FNF (100, 85 e 70% das exigências da ave), totalizando seis tratamentos com cinco repetições de 11 aves cada. Não houve efeito da interação FNF vs fitase e dos níveis de FNF ou fitase sobre a retenção de matéria seca e de fósforo, e a interação FNF vs fitase foi significativa para retenção de proteína bruta e coeficiente de digestibilidade ileal da matéria seca. A suplementação com fitase, independente dos níveis de FNF, melhorou o coeficiente digestibilidade ileal da proteína bruta, do cálcio e do fósforo. A retenção de cálcio e a redução dos níveis de FNF diminuíam a metabolização da energia bruta das dietas com 85 e 70% das exigências de FNF. Dietas com nível de 70% das exigências de FNF, suplementadas com fitase, podem ser usadas para frangos de corte sem prejuízos à digestibilidade ileal e retenção da matéria seca, proteína bruta, cálcio e fósforo e à metabolização da energia bruta.

Inulin and oligofructose and mineral metabolism: the evidence from animal trials

Nondigestible oligosaccharides have been shown to increase the absorption of several minerals (calcium, magnesium, in some cases phosphorus) and trace elements (mainly copper, iron, zinc). Inulin-type fructans including oligofructose and fructooligosaccharides derived from sucrose by enzymatic transfructosylation are the best investigated food ingredients in this respect. The stimulation of absorption was more pronounced when the demand for calcium was high, i.e., in animals in the rapid growing stage and in animals with impaired calcium absorption because of either ovariectomy or gastrectomy. Even a small stimulation of calcium absorption increased the mineral accumulation in the skeleton because of its persisting effect over months. Inulin-type fructans stimulated mineral absorption and bone mineral accretion when combined with probiotic lactobacilli and in the presence of antibiotics. Direct comparison of different inulin-type fructans revealed a more pronounced effect by inulin or a mixture of long-chain inulin and oligofructose than by oligofructose alone. Mechanisms on how inulin-type fructans mediate this effect include acidification of the intestinal lumen by short-chain fatty acids increasing solubility of minerals in the gut, enlargement of the absorption surface, increased expression of calcium-binding proteins mainly in the large intestine, modulated expression of bone-relevant cytokines, suppression of bone resorption, increased bioavailability of phytoestrogens, and, via stimulation of beneficial commensal microorganisms, increase of calcium uptake by enterocytes. Under certain conditions, inulin-type fructans may improve mineral absorption by their impact on the amelioration of gut health including stabilization of the intestinal flora and reduction of inflammation. The abundance of reports indicate that inulin-type fructans are promising substances that could help to improve the supply with available calcium in human nutrition and by this contribute to bone health.

Prebiotics, probiotics, and synbiotics affect mineral absorption, bone mineral content, and bone structure

Several studies in animals and humans have shown positive effects of nondigestible oligosaccharides (NDO) on mineral absorption and metabolism and bone composition and architecture. These include inulin, oligofructose, fructooligosaccharides, galactooligosaccharides, soybean oligosaccharide, and also resistant starches, sugar alcohols, and difructose anhydride. A positive outcome of dietary prebiotics is promoted by a high dietary calcium content up to a threshold level and an optimum amount and composition of supplemented prebiotics. There might be an optimum composition of fructooligosaccharides with different chain lengths (synergy products). The efficacy of dietary prebiotics depends on chronological age, physiological age, menopausal status, and calcium absorption capacity. There is evidence for an independent probiotic effect on facilitating mineral absorption. Synbiotics, i.e., a combination of probiotics and prebiotics, can induce additional effects. Whether a low content of habitual NDO would augment the effect of dietary prebiotics or synbiotics remains to be studied. The underlying mechanisms are manifold: increased solubility of minerals because of increased bacterial production of short-chain fatty acids, which is promoted by the greater supply of substrate; an enlargement of the absorption surface by promoting proliferation of enterocytes mediated by bacterial fermentation products, predominantly lactate and butyrate; increased expression of calcium-binding proteins; improvement of gut health; degradation of mineral complexing phytic acid; release of bone-modulating factors such as phytoestrogens from foods; stabilization of the intestinal flora and ecology, also in the presence of antibiotics; stabilization of the intestinal mucus; and impact of modulating growth factors such as polyamines. In conclusion, prebiotics are the most promising but also best investigated substances with respect to a bone-health-promoting potential, compared with probiotics and synbiotics. The results are more prominent in animal models, where more studies have been performed, than in human studies, where experimental conditions are more difficult to control.

Avian multiple inositol polyphosphate phosphatase is an active phytase that can be engineered to help ameliorate the planet's "phosphate crisis"

Contemporary phytase research is primarily concerned with ameliorating the problem of inadequate digestion of inositol hexakisphosphate (phytate; InsP6) in monogastric farm animal feed, so as to reduce the pollution that results from the high phosphate content of the manure. In the current study we pursue a new, safe and cost-effective solution. We demonstrate that the rate of hydrolysis of InsP6 by recombinant avian MINPP (0.7 micromol/mg protein/min) defines it as by far the most active phytase found to date in any animal cell (the corresponding activity of recombinant mammalian MINPP is only 0.006 micromol/mg protein/min). Although avian MINPP has less than 20% sequence identity with microbial phytases, we create a homology model of MINPP in which it is predicted that the structure of the phytase active site is well-conserved. This model is validated by site-directed mutagenesis and by use of a substrate analogue, scyllo-InsP6, which we demonstrate is only a weak MINPP substrate. In a model chicken cell line, we overexpressed a mutant form of MINPP that is secretion-competent. This version of the enzyme was actively secreted without affecting either cell viability or the cellular levels of any inositol phosphates. Our studies offer a genetic strategy for greatly improving dietary InsP6 digestion in poultry.

Mucin dynamics and microbial populations in chicken small intestine are changed by dietary probiotic and antibiotic growth promoter supplementation

The mucous layer that covers the intestinal absorptive surface acts as a barrier against bacterial translocation. The chicken gut contains a diverse bacterial population which interacts with the mucous layer. In this report, we studied the effect of changing the intestinal microbial populations on mucin dynamics by feeding 1-d-old chicks a control diet or that diet containing either antibiotic growth promoter (AGP) or a probiotic product for 14 d. Dietary AGP increased the proportions of Bifidobacterium species in the duodenum compared with the other groups. In AGP-fed chicks, the villous surface area was increased in the jejunum, goblet cell density was greater in the jejunum and ileum, and mucin glycoprotein levels in the duodenum were lower than in the other groups (P < 0.05). Feeding AGP increased the expression of mucin mRNA in the jejunum and ileum compared with controls. The dietary probiotic increased the proportion of Lactobacillus species in the ileum compared with the controls (P < 0.05) and significantly enlarged the goblet cell "cup" area throughout the small intestine compared with the other groups. Expression of mucin mRNA and the levels of mucin glycoprotein were greater in the jejunum of the probiotic-fed chicks compared with controls (P < 0.05). Neither the probiotic nor AGP treatments affected the thickness of the mucous adherent layer. These results indicate that both probiotic and AGP altered processes of mucin biosynthesis and/or degradation mediated via changes in the intestinal bacterial populations. These modifications in mucin dynamics influence gut function and health and may change nutrient uptake.