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The jejunum plays crucial roles for the digestion and absorption of nutrients and minerals and for barrier functions that are essential for a healthy, productive life cycle of farm animals, including laying hens. Accordingly, knowledge of the molecular pathways that emerge in the intestine during development, and particularly at the beginning of laying activity, will help to derive strategies for improving nutrient efficiency in laying hens. In this study, jejunal samples were obtained from two high-yielding layer strains at five developmental stages (weeks 10, 16, 24, 30 and 60 of life) for RNA-sequencing, alongside the profiling of blood plasma parameters to approximate the dynamics of mineral homeostasis. The results reflected a marked distinction between the pre-laying and laying phase as inferred from levels of parathyroid hormone, triiodothyronine, estradiol, vitamin D, and calcium. Moreover, the expression patterns of the intestinal mucosa responded directly to the changing metabolic and nutritional profiles at the beginning of the laying phase in maturing high-yielding strains of laying hens. These comprise signaling events namely RANK/RANKL signaling and cellular senescence. Taken together, the timing of sexual maturity of laying hens demands closer examination to unravel metabolic requirements and associated endogenous mechanisms.

BACKGROUND The variation in amino acid (AA) digestibility and metabolisable energy (MEN ) in four spring and four winter faba bean genotypes differing in vicine/convicine (V/C) concentrations grown on two sites was investigated in caecectomised LSL-Classic laying hens. Effects of dehulling one faba bean genotype were also examined. Diets containing one out of 17 faba bean variants each and a basal diet were fed to ten caecectomised laying hens in a row-column design to achieve five replicates per diet. RESULTS Ranges and levels of digestibility of the hulled variants differed widely among AA with the lowest and highest range determined for Arg (90-93%) and Cys (-12-65%), respectively. MEN ranged between 10.3 and 12.3 MJ kg-1 dry matter. Lower MEN and digestibility of Cys, Glx, Phe, Pro, Tyr, and Val (P

There is growing evidence of the importance of miRNAs for intestinal functional properties and nutritional uptake. Comparative miRNAs profiles of the jejunal mucosa were established against two genetic backgrounds (Lohmann Brown-Classic (LB) and Lohmann LSL-Classic (LSL), which are similar in egg production but differ in physiological traits including mineral utilization, along the production periods of laying hens. The target genes of miRNAs higher expressed in LB vs. LSL (miR-126-3p, miR-214, miR-24-3p, miR-726-5p, miR-29b-3p) were enriched for energy pathways at all stages. The target genes of the miRNAs higher in LSL (miR-1788-5p, miR-103-3p, miR-22-5p, miR-221-3p, miR-375) were more enriched for immune and the bone signalling pathways . The most prominent expression differences were between 16 and 24 weeks of age before and after onset of laying. Our results evidence central roles of intestinal miRNAs as regulators of gene expression, influencing intestinal homeostasis and adaptation to environment in different strains and production phases.

The objective of this study was to compare 2 laying hen strains in 5 production periods regarding phytase activity, phytate (InsP6) degradation, and myo-inositol (MI) release in the digestive tract and phosphorus (P) and calcium (Ca) utilization. One offspring of 10 nonrelated roosters per strain (Lohmann Brown-classic (LB) or Lohmann LSL-classic (LSL)) was placed in one of 20 metabolic units in a completely randomized block design in week 8, 14, 22, 28, and 58 of life. All hens were fed the same corn and soybean meal–based diet at one time, but the diet composition was adjusted to the requirements in the respective period. For 4 consecutive days, excreta were collected quantitatively at 24-hour intervals. In week 10, 16, 24, 30, and 60, the blood plasma, digesta of crop, gizzard, jejunum, ileum, and ceca, and mucosa of the jejunum was collected. The concentration of inorganic P in the blood plasma was higher in LB than in LSL hens (P = 0.026). Plasma Ca concentrations increased with each period (P

As a constituent of animal cells, myo-inositol (MI) has been hypothesized to be crucial in several metabolic and regulatory pathways. Recently, it was shown that dietary phytase contributes to release of MI from phytate in the poultry digestive tract, increasing its systemic concentrations. This study investigated the activities of phosphatases in the jejunum and systemic plasma MI concentration in broilers not supplemented or supplemented with phytase through analyses based on modifications from commercial enzyme activity kits. Three hundred sixty male Ross 308 broilers were randomly allocated to 24 pens (15 birds per pen) in 4 dietary groups. The positive control group was fed with an adequate basal diet. The negative control group (NC) was fed with a reduced level of P and Ca. Groups Phy1500 and Phy3000 were fed with the NC diet plus 1,500 or 3,000 FTU of phytase per kilogram of feed, respectively. One bird per pen was selected for the measurement of jejunal phosphatase activity; MI concentration in plasma, the liver, and the kidney; and key MI enzyme concentrations (liver inositol monophosphatase 1 [IMPase 1] and kidney myo-inositol oxygenase [MIOX]). Endogenous phytase and alkaline phosphatase activity as well as IMPase 1 and MIOX expression were not statistically different among the dietary groups. The supplementation of 1500 FTU of phytase per kilogram of feed resulted in increase of plasma (P < 0.001) and kidney (P < 0.05) but not liver MI concentrations. The results indicated that systemic MI might reflect MI released from dietary sources; however, it did not appear to change expression of enzymes related to endogenous MI synthesis in the liver and catabolism in the kidney. New and larger studies are necessary to reach stronger evidence on the effects of dietary phytase on intestinal and systemic MI concentrations in broilers.

Durum wheat is mainly used in pasta production, but may also be used as animal feed, for example as concentrate for dairy cows. Data on the ruminal degradation of Durum grains are scarce. Hence, the objective of the present study was to describe ruminal in situ crude protein (CP) and starch (ST) degradation, to investigate in vitro gas production kinetics, and to estimate utilisable CP at the duodenum (uCP) in vitro of five Durum varieties from three growing locations. Metabolisable energy (ME) and digestibility of organic matter (dOM) were also estimated using in vitro data. In situ incubations were conducted in three lactating jersey cows over defined timespans from 1 to 72 hr. Ruminal degradation parameters were estimated using exponential regression, and effective ruminal degradation was predicted for a ruminal passage rate of 8%/hr (ED8 ). In situ CP (a = 11%-19%; b = 80%-88%; c = 23%-33%/hr) and ST (a = 22%-39%; b = 60%-78%; c = 61%-123%/hr) degradation kinetics varied among samples and were influenced by location. Some samples showed a remarkably high ST degradation rate of up to 123%/h, which can significantly influence rumen pH and health when high amounts are incorporated into dairy rations. However, the ED of CP (77%-82%) and ST (91%-95%), and the in vitro estimates of ME (13.6-14.1 MJ/kg DM), dOM (92%-96%), and uCP (183-195 k/g DM) varied within a relatively small range. Hence, it may be adequate to use the mean values of these Durum grain characteristics when rations for ruminants are calculated and a differentiation depending on variety and location may not be necessary.

It is well known that mammals and avian gut microbiota compositions are shaped by the host genomes and affect quantitative traits. The microbial architecture describes the impact of the microbiota composition on quantitative trait variation and the number and effect distribution of microbiota features. In the present study the gut microbial architecture of feed-related traits phosphorus and calcium utilization, daily gain, feed intake and feed per gain ratio in the domestic poultry model species Japanese quail were assessed by mixed linear models. The ileum microbiota composition was characterized by 16S rRNA amplicon sequencing techniques of growing individuals. The microbiability of the traits was on a similar level as the narrow sense heritability and was highly significant except for calcium utilization. The animal microbial correlation of the traits was substantial. Microbiome-wide association analyses revealed several traits associated and highly significant microbiota features, both on the bacteria genera as well as on the operational taxonomic unit level. Most features were significant for more than one trait, which explained the high microbial correlations. It can be concluded that the traits are polymicrobial determined with some microbiota features with larger effects and many with small effects. The results are important for the development of hologenomic selection schemes for feed-related traits in avian breeding programs that are targeting the host genome and the metagenome simultaneously.

During life, the number and function of immune cells change with potential consequences for immunocompetence of an organism. In laying hens, studies have primarily focused on early development of immune competence and only few have investigated systemic and lymphatic distribution of leukocyte subsets during adolescence and the egg-laying period. The present study determined the number of various leukocyte types in blood, spleen, and cecal tonsils of 10 Lohmann Brown-Classic and 10 Lohmann LSL-Classic hens per wk of life 9/10, 15/16, 23/24, 29/30, and 59/60, encompassing important production as well as developmental stages, by flow cytometry. Although immune traits differed between the 2 hen strains, identical patterns of age-related immunological changes were found. The numbers of all investigated lymphocyte types in the spleen as well as the numbers of blood γδ T cells increased from wk 9/10 to 15/16. This suggests an ongoing release of lymphocytes from primary lymphoid tissues and an influx of blood lymphocytes into the spleen due to novel pathogen encounters during adolescence. A strong decrease in the number of CTL and γδ T cells and an increase in innate immune cells within blood and spleen were found between wk of life 15/16 and 23/24, covering the transition phase to egg-laying activity. Numbers of peripheral and splenic lymphocytes remained low during the egg-laying period or even further decreased, for example blood CD4+ T cells and splenic γδ T cells. Functional assessments showed that in vitro IFN-γ production of mitogen-stimulated splenocytes was lower in wk 60. Taken together, egg-laying activity seems to alter the immune system toward a more pronounced humoral and innate immune response, with probable consequences for the immunocompetence and thus for productivity, health and welfare of the hens.

Most traits in animal breeding, including feed efficiency traits in pigs, are affected by many genes with small effect and have a moderately high heritability between 0.1 and 0.5, which enables efficient selection. Since the microbiota composition in the gastrointestinal tract is also partly heritable and was shown to have a substantial effect on feed efficiency, the host genes affect the phenotype not only directly by altering metabolic pathways, but also indirectly by changing the microbiota composition. The effect m i of the microbiota composition on the breeding value g i of an animal i is the conditional expectation of its breeding value, given the vector φ i with microbiota frequencies, that is m i = E g i | φ i . The breeding value g i of an animal can therefore be decomposed into a heritable contribution m i that arises from an altered microbiota composition and a heritable contribution p i that arises from altered metabolic pathways within the animal, so g i = m i + p i . Instead of selecting for breeding value g ^ i , an index comprising the two components m ^ i and p ^ i with appropriate weights, that is I i = λ 1 m ^ i + λ 2 p ^ i , can be used. The present study shows how this breeding strategy can be applied in pig genomic selection breeding scheme for two feed efficiency traits and daily gain.

The main objective of this study was to perform quantitative genetic analyses of tibia and foot ash traits, which might serve as proxy traits to improve phosphorus utilization (PU) in a breeding program. Additionally, data for ash concentration in tibia and foot were compared with data for total amount of ash. Heritabilities for bone ash traits and genetic and phenotypic correlations between bone ash traits and PU were estimated. A total of 887 F2 birds, established from 2 Japanese quail lines divergently selected on social reinstatement behavior, were provided a P deficient diet. In a metabolic study, feed consumption was measured and total excreta collected for each bird separately. Afterwards, birds were euthanized, the bones obtained and incinerated. Bone ash data showed a heritability of 0.230 (amount of tibia ash) to 0.342 (amount of foot ash), which was higher than estimated for PU, P retention, calcium utilization (0.120–0.174), and performance traits (0.088–0.114). The strongest genetic and phenotypic correlations between PU and bone ash traits were detected for the amount of foot ash with 0.549 and 0.527, respectively. Genetic and phenotypic correlations were stronger between PU and ash amount than between PU and ash percentage, irrespective of bone. Therefore, ash amount was considered a better trait than ash percentage to reflect PU. Strong genetic and phenotypic correlations were detected between the amount of foot and tibia ash (0.887 and 0.901, respectively). Phenotypic and genetic correlations between ash amount and PU or calcium utilization were almost identical, irrespective of bone. Foot ash is as suitable as tibia ash, but easier to determine. Bone ash data, especially the amount of foot ash, seem to be suitable indirect selection criteria for P efficiency breeding.

The objective of this study was to determine the effects of protease origin and dosage on the prececal (pc) amino acid (AA) digestibility and the influence on composition of the microbial community in the small intestine. In addition, the effects of phytase supplementation were investigated. A total of 8 dietary treatments were included. The basal diet contained mainly corn and soybean meal. Three protease products were added to the basal diet, each at the level recommended by the supplier and at an 8-fold level. Phytase was supplemented in another dietary treatment. Each dietary treatment was allocated to 8 replicates of 15 birds each. The experimental diets were offered from day 15 to 21 for ad libitum consumption. The effect of protease supplementation on the pc AA digestibility depended on the protease product type and the amount supplemented. The pc AA digestibility was significantly increased by 1 protease product when supplemented at high level and when phytase was supplemented. In all the other treatments, protease supplementation had no significant influence or it decreased pc AA digestibility, when compared with the treatment with no enzymes added. In general, Firmicutes was the most abundant phylum among the ileal microbiota across all the treatments. Significant effects on microbiota composition were observed at the genus level for some but not all protease treatments and phytase supplementation. The genera Streptococcus, Lactobacillus, and uncultured Clostridiaceae were responsible for these differences. Furthermore, microbial networks established for each diet showed either high or low number of intergeneric interactions, but without a consistent enzyme effect. We conclude that enzyme supplementation effects were evident in the terminal small intestine microbiota composition, and to a lesser extent, in pc AA digestibility. However, the changes in microbiota composition and pc AA digestibility could not be correlated, indicating absence of a causal relationship.

The objectives of the present study were to investigate the single and interactive effects of mineral phosphorus (P) (monoammonium phosphate; MAP; 1 g P/kg DM of diet) and Aspergillus oryzae 6-phytase (2800 FTU/kg DM diet) supplements on the disappearance of phytic acid (InsP6) and its lower inositol phosphate isomers (InsPs) and related P digestibility effects in Atlantic salmon (S. salar) and rainbow trout (O. mykiss). For each species, one experiment was conducted applying species-specific conditions but using the same diets in both experiments. Faeces were obtained by stripping the fish. The faecal InsP6 disappearance was similar in Atlantic salmon (8.6%) and rainbow trout (8.1%) when diets did not contain the MAP or phytase supplement. Phytase supplementation significantly increased InsP6 disappearance in both species, but to a larger extent in rainbow trout. The hydrolysis of lower inositol phosphate isomers progressed to a greater extent in rainbow trout. Supplementation of MAP had no significant effect on InsP6 disappearance in rainbow trout but slightly decreased InsP6 disappearance in Atlantic salmon. No significant interactive effect of the supplements on InsP6 disappearance was detected in both experiments. The analysis of InsPs in the faeces of the two species suggested that the degradation pathway of InsP6 differed between the two species. In both species, each supplement increased the amount of digested P. This effect was additive in rainbow trout but not in Atlantic salmon. In Atlantic salmon, the MAP supplementation decreased the efficacy of phytase by reducing the amount of digested InsP-P to negligible amounts. However, no significant interactive effect of MAP and phytase supplementation on P digestibility, digested P, and digested InsP-P was detected in either species. The present study provided insight into details of InsP6 degradation in the digestive tract and revealed similarities and differences between the two fish species. The effects of phytase in Atlantic salmon when using low-P diets may not be the same for commercial diets that contain more inorganic P.

The objective of this study was to compare the effects of graded inclusions of 2 phytase products and a mineral P source in broiler chickens using different response traits, including ileum microbiota composition. Eleven experimental diets were used. These were a low-P basal diet and diets supplemented with increasing levels of dicalcium phosphate (DCP), Natuphos E 5000 G (NE), or Natuphos 5000 G (N). The performance traits, prececal P digestibility, and tibia and foot ash results were subjected to regression analysis and slope ratios were used to compare the supplements based on the measured evaluation traits. In the microbiota analysis, total nucleic acids were extracted and the 16S rRNA gene was targeted for use in the amplicon sequencing process. Phylogenetic analysis was performed using Mothur, followed by a multivariate statistical analysis. The various response traits caused different estimates of relative efficacy. The mean results of all the response traits showed that a 1.75-fold increase in the activity of N was needed to achieve the same response as NE and the variability among the detected traits ranged from 1.59 (prececally digestible P intake) to 1.91 (amount of tibia ash). The mean slope ratio between DCP and NE was 311 and varied between 208 (ADG) and 349 (foot ash concentration). The mean slope ratio for phytase N with DCP was 552 and varied from 357 (ADG) to 640 (tibia ash concentration). The ileum microbiota composition was not different among the diets. A similar composition was driven in the abundance of Lactobacillus crispatus, Lactobacillus salivarius, and Lactobacillus gallinarum. The results suggest that different response traits cause markedly different estimates of relative phytase efficacy.

Background Diet acidification, dietary calcium (Ca) level, and phytase supplementation are known influences on the microbial community in the digestive tract and on phosphorus (P) utilization of broiler chickens. Effects of dietary factors and microbiota on P utilization may be linked because microorganisms produce enzymes that release P from phytate (InsP6), the main source of P in plant feedstuffs. This study aimed to detect linkages between microbiota and InsP6 degradation by acidifying diets (i.e., replacing Ca carbonate (CaCO3) by Ca formate or adding formic acid to CaCO3-containing diets), varying Ca levels, and supplementing phytase in a three-factorial design. We investigated i) the microbial community and pH in the digestive tract, ii) prececal (pc) P and Ca digestibility, and iii) InsP6 degradation. Results All factors under investigation influenced digesta pH and the microbiota composition. Predicted functionality and relative abundance of microorganisms indicated that diets influenced the potential contribution of the microbiota on InsP degradation. Values of InsP6 degradation and relative abundance of the strains Lactobacillus johnsonii and Lactobacillus reuteri were correlated. Phytase supplementation increased pc InsP6 disappearance, with differences between Ca levels, and influenced concentrations of lower inositol phosphate isomers in the digestive tract. Formic acid supplementation increased pc InsP6 degradation to myo-inositol. Replacing CaCO3 by Ca-formate and the high level of these Ca sources reduced pc InsP6 disappearance, except when the combination of CaCO3 + formic acid was used. Supplementing phytase to CaCO3 + formic acid led to the highest InsP6 disappearance (52%) in the crop and increased myo-inositol concentration in the ileum digesta. Supplementing phytase leveled the effect of high Ca content on pc InsP6 disappearance. Conclusions The results point towards a contribution of changing microbial community on InsP6 degradation in the crop and up to the terminal ileum. This is indicated by relationships between InsP6 degradation and relative abundance of phosphatase-producing strains. Functional predictions supported influences of microbiota on InsP6 degradation. The extent of such effects remains to be clarified. InsP6 degradation may also be influenced by variation of pH caused by dietary concentration and solubility of the Ca in the feed.

Adaptation to metabolic challenges is an individual process in animals and human, most likely based on genetic background. To identify novel pathways of importance for individual adaptation to a metabolic challenge such as egg production in laying hens, myo-inositol (MI) metabolism and plasma metabolite profiles during the productive lifespan were examined in two genetically different strains, Lohmann Brown-Classic (LB) and LSL-Classic (LSL) hens. They were housed during the productive lifespan and sampled at 10, 16, 24, 30 and 60 weeks of age. The targeted AbsoluteIDQ p180 Kit was used for metabolite profiling in plasma whereas a MI enzymatic kit and ELISAs were used to quantify tissue MI concentrations and MI key enzymes (IMPase 1 and MIOX), respectively. As major finding, kidney MIOX was differently expressed in LB and LSL hens with higher amounts in LB. The onset of egg laying between week 16 and 24 of life span was associated with a clear change in the metabolite profiles, however LSL hens and LB hens adapt differently. Pearson’s correlation analyses over all hens at all time points indicated that higher expression of MI degrading enzyme MIOX was related to markers indicating metabolic stress.

Improved utilization of phytates and mineral phosphorus (P) in monogastric animals contributes significantly to preserving the finite resource of mineral P and mitigating environmental pollution. In order to identify pathways and to prioritize candidate genes related to P utilization (PU), the genomic heritability of 77 and 80 trait-dependent expressed miRNAs and mRNAs in 482 Japanese quail were estimated and eQTL (expression quantitative trait loci) were detected. In total, 104 miR-eQTL (microRNA expression quantitative traits loci) were associated with SNP markers (false discovery rate less than 10%) including 41 eQTL of eight miRNAs. Similarly, 944 mRNA-eQTL were identified at the 5% False discovery rate threshold, with 573 being cis-eQTL of 36 mRNAs. High heritabilities of miRNA and mRNA expression coincide with highly significant eQTL. Integration of phenotypic data with transcriptome and microbiome data of the same animals revealed genetic regulated mRNA and miRNA transcripts (SMAD3, CAV1, ENNPP6, ATP2B4, miR-148a-3p, miR-146b-5p, miR-16-5p, miR-194, miR-215-5p, miR-199-3p, miR-1388a-3p) and microbes ( Candidatus Arthromitus , Enterococcus ) that are associated with PU. The results reveal novel insights into the role of mRNAs and miRNAs in host gut tissue functions, which are involved in PU and other related traits, in terms of the genetic regulation and inheritance of their expression and in association with microbiota components.

Background Calcium (Ca) and phosphorus (P) are essential nutrients that are linked to a large array of biological processes. Disturbances in Ca and P homeostasis in chickens are associated with a decline in growth and egg laying performance and environmental burden due to excessive P excretion rates. Improved utilization of minerals in particular of P sources contributes to healthy growth while preserving the finite resource of mineral P and mitigating environmental pollution. In the current study, high performance Lohmann Selected Leghorn (LSL) and Lohmann Brown (LB) hens at peak laying performance were examined to approximate the consequences of variable dietary Ca and P supply. The experimental design comprised four dietary groups with standard or reduced levels of either Ca or P or both (n = 10 birds per treatment group and strain) in order to stimulate intrinsic mechanisms to maintain homeostasis. Jejunal transcriptome profiles and the systemic endocrine regulation of mineral homeostasis were assessed (n = 80). Results Endogenous mechanisms to maintain mineral homeostasis in response to variations in the supply of Ca and P were effective in both laying hen strains. However, the LSL and LB appeared to adopt different molecular pathways, as shown by circulating vitamin D levels and strain-specific transcriptome patterns. Responses in LSL indicated altered proliferation rates of intestinal cells as well as adaptive responses at the level of paracellular transport and immunocompetence. Endogenous mechanisms in LB appeared to involve a restructuring of the epithelium, which may allow adaptation of absorption capacity via improved micro-anatomical characteristics. Conclusions The results suggest that LSL and LB hens may exhibit different Ca, P, and vitamin D requirements, which have so far been neglected in the supply recommendations. There is a demand for trial data showing the mechanisms of endogenous factors of Ca and P homeostasis, such as vitamin D, at local and systemic levels in laying hens.

A large F2 cross with 920 Japanese quail was used to map QTL for phosphorus utilization, calcium utilization, feed per gain and body weight gain. In addition, four bone ash traits were included, because it is known that they are genetically correlated with the focal trait of phosphorus utilization. Trait recording was done at the juvenile stage of the birds. The individuals were genotyped genome-wide for about 4k SNPs and a linkage map constructed, which agreed well with the reference genome. QTL linkage mapping was performed using multimarker regression analysis in a line cross model. Single marker association mapping was done within the mapped QTL regions. The results revealed several genome-wide significant QTL. For the focal trait phosphorus utilization, a QTL on chromosome CJA3 could be detected by linkage mapping, which was substantiated by the results of the SNP association mapping. Four candidate genes were identified for this QTL, which should be investigated in future functional studies. Some overlap of QTL regions for different traits was detected, which is in agreement with the corresponding genetic correlations. It seems that all traits investigated are polygenic in nature with some significant QTL and probably many other small-effect QTL that were not detectable in this study.

The study was conducted to determine the effects of high levels of phytase on growth performance, nutrient digestibility, phytate breakdown, and expression of mucosal tight junction and nutrient transporter genes in weanling pigs. A total of 128 barrows were penned in groups of four and used in a randomized completely block design and assigned to four treatments for a 28-d study. A two-phase feeding was implemented (phase 1: day 1 to 14; phase 2: day 15 to 28). The diets differed in dietary calcium (Ca) and phosphorus (P) levels (positive control [PC]: 8.1 to 7.1 g/kg Ca and 6.5 to 6.8 g/kg P; negative control [NC]: 6.6 to 5.5 g/kg Ca and 5.6 to 5.3 g/kg P) from phase 1 to phase 2, respectively. NC diets were supplemented with phytase at 0 (NC), 1,500 (NC + 1,500), or 3,000 (NC + 3,000) phytase units (FTU)/kg. Blood was collected after fasting (day 27) or feeding (day 28) for the measurement of plasma inositol concentrations. On day 28, two pigs per pen were euthanized. Duodenal–jejunal and ileal digesta samples and feces were collected to determine inositol phosphates (InsP3-6) concentrations. Phytase supplementation increased the body weight on days 14 and 28 (P < 0.05). Average daily gain and feed efficiency compared with NC were increased by phytase with the majority of its effect in phase 1 (P < 0.05). The apparent ileal digestibility and apparent total tract digestibility of P were increased in piglets fed phytase-supplemented diets (P < 0.01) compared with NC piglets. Disappearance of InsP6 and total InsP3-6 up to the duodenum–jejunum, ileum, and in feces was increased by both phytase application rates (P < 0.01). Plasma concentrations of myo-inositol were higher (P < 0.001) in the phytase-supplemented diets than PC and NC diets, irrespective of whether pigs were fed or fasted. Expression of claudin 3 was higher in pigs fed both phytase-supplemented diets in the duodenum and jejunum compared with PC and NC. Mucin 2 expression was lower in the ileum of NC + 3,000 fed piglets compared with PC (P < 0.05), whereas expression of GLUT2 (solute carrier family 2-facilitated glucose transporter member 2) was increased (P < 0.05) by the NC + 3,000 treatment in all sections. In summary, high phytase supplementation increased the growth performance of nursery pigs. The increased expression of GLUT2 by phytase may indicate an upregulation of glucose absorption from the intestine by phytase.

The current study was conducted to evaluate the component composition, anti-nutritional factors, in vitro gas production (GP) and methane (CH4) production profiles of fruit by-products (pineapple pulp, mango seed kernels, banana and papaya peel, Moringa stenopetala and Moringa oleifera seeds) and leaves of root crops (sweet potato [Ipomoea batatas], cassava [Manihot esculenta], yam [Dioscorea abyssinica], enset [Ensete ventricosum] and samma [Urtica simensis]). Root crop leaves had high crude protein (CP) ranging from 211 to 318 g/kg dry matter (DM) in yam and samma, respectively. M. stenopetala seeds contained the highest CP (450 g/kg DM). Samma leaves were rich in calcium (58.6 g/kg DM) and iron (1186 mg/kg DM). Leaves of root crops had similar concentrations of essential amino acids with appreciable values. Total phenols were highest in mango seed kernels (158 g/kg DM). The asymptotic GP at 96 h incubation of pineapple pulp, papaya and banana peel was 397, 358 and 279 ml/g DM, respectively, and differed significantly from each other. Sweet potato and yam leaves produced 238 and 225 ml/g DM GP, respectively, being significantly higher than those of other root crops. CH4 production was significantly lowest in Moringa seeds, mango seed kernels and sweet potato leaves. In conclusion, fruit by-products have the potential as energy sources and root crop leaves as protein supplements for ruminant and non-ruminant animals. Moringa seeds, mango seed kernels and sweet potato leaves were identified as potential candidates in mitigating CH4 emissions in tropical livestock with animal-based experiments recommended to validate the in vitro findings.

The objectives of this study were to investigate the digestibility of pumpkin seed cake (PSC) for the rainbow trout, Oncorhynchus mykiss (Walbaum, 1792), and effects on performance and product quality traits of four different fish species when PSC partially replaced fishmeal in extruded diets. A digestibility trial was carried out to determine apparent digestibility coefficients (ADC) for crude protein (CP), ether extract (EE) and gross energy (GE) of PSC fed to rainbow trout. In subsequent growth trials, effects on performance and morphological traits and fillet colour values of four different fish species [rainbow trout; brook trout, Salvelinus fontinalis (Mitchill, 1814); African sharptooth catfish, Clarias gariepinus (Burchell, 1822); and wels catfish, Silurus glanis (Linnaeus, 1758)] were evaluated when 60% of fishmeal protein of a reference diet was replaced by PSC protein (based on digestible CP). Nutrient ADC of PSC were high (CP: 89%, EE: 88% and GE: 84%). No significant effects on growth and only minor effects on fillet colour were detected in the trials. However, replacing fishmeal with PSC at the chosen level affected morphological traits and feed conversion in all four species to different extents. Replacement effects of PSC should be tested at lower levels of inclusion before conclusions are drawn on its suitability in fish diets.

This study examined whether the methane-decreasing effect of monensin (∼21%) and different hydrolysable tannins (24%–65%) during in vitro fermentation of grass silage was accompanied by changes in abundances of cellulolytics and methanogens. Samples of liquid (LAM) and solid (SAM) associated microbes were obtained from two rumen simulation technique experiments in which grass silage was either tested in combination with monensin (0, 2 or 4 mg d−1) or with different tannin extracts from chestnut, valonea, sumac and grape seed (0 or 1.5 g d−1). Total prokaryotes were quantified by 4′,6-diamidino-2-phenylindol (DAPI) staining of paraformaldehyde-ethanol-fixed cells and relative abundances of ruminal cellulolytic and methanogenic species were assessed by real time quantitative PCR. Results revealed no change in absolute numbers of prokaryotic cells with monensin treatment, neither in LAM nor in SAM. By contrast, supplementation of chestnut and grape seed tannins decreased total prokaryotic counts compared to control. However, relative abundances of total methanogens did not differ between tannin treatments. Thus, the decreased methane production by 65% and 24% observed for chestnut and grape seed tannins, respectively, may have been caused by a lower total number of methanogens, but methane production seemed to be also dependent on changes in the microbial community composition. While the relative abundance of F. succinogenes decreased with monensin addition, chestnut and valonea tannins inhibited R. albus. Moreover, a decline in relative abundances of Methanobrevibacter sp., especially M. ruminantium, and Methanosphaera stadtmanae was shown with supplementation of monensin or chestnut tannins. Proportions of Methanomicrobium mobile were decreased by monensin in LAM while chestnut and valonea had an increasing effect on this methanogenic species. Our results demonstrate a different impact of monensin and tannins on ruminal cellulolytics and gave indication that methane decrease by monensin and chestnut tannins was associated with decreased abundances of M. ruminantium and M. stadtmanae.

The aim of this study was to evaluate the P digestibility of different wheat and triticale genotypes in growing broiler chickens. Additionally, the relationships between physical or chemical properties of genotypes and P digestibility were determined. A low P, low Ca basal diet based on cornstarch and soybean meal was supplemented with 20% or 40% of 8 different wheat or triticale genotypes at the expense of cornstarch. Experimental diets were fed to broilers between d 20 and 26 of age before digesta samples were collected from their lower ileum for determination of prececal P digestibility (pcdP). Triticale-based diets had an average pcdP of 54%. Neither the concentration of triticale nor the genotype itself affected the pcdP of diets. The pcdP of triticale genotypes calculated by linear regression analysis ranged from 53% to 78%. No correlations were found between physical or chemical properties (viscosity, phytase activity, total and phytate P contents) and the pcdP of triticale genotypes. In contrast, a significant (P < 0.05) effect of genotype and wheat concentration was observed in wheat-based diets. The average pcdP of diets decreased from 60% to 50% by increasing the wheat concentration from 20% to 40%. As no linear relationship was observed between P intake and the amount of pcdP in the diet, the pcdP (%) of wheat genotypes was calculated separately for both concentrations, and accounted for 38% to 67% and 20% to 38% with 20% and 40% wheat inclusion in diets, respectively. Single chemical and physical characteristics could not explain the observed differences in P digestibility. Our results revealed a high variation in the pcdP of different wheat and triticale genotypes that should be considered in diet formulation. However, further research is needed to identify factors that contribute to variation of P digestibility in both grains.

Summary Rations for dairy cows are comprised of high proportions of cereal grains. Thus, despite their low crude protein (CP) content, grains can contribute considerably to the CP intake of dairy cows. This study was conducted to describe and compare ruminal CP degradation of a broad range of barley, rye and triticale genotypes in situ and in vitro and different methods to estimate the utilisable CP at the duodenum (uCP). Twenty samples each of rye, barley and triticale were incubated in situ and in vitro. Exponential regression analyses were used to estimate in situ degradation parameters. Further, the effective degradability (ED), ruminal undegraded CP (UDP) and uCP for ruminal passage rates of 5% and 8% per hr were estimated. The uCP was estimated in vitro and based on two different approaches using in situ UDP data and estimates of microbial synthesised protein (based on fermented organic matter [fOM] or equations of the Gesellschaft fur Ernahrungsphysiologie). The degradation rate declined from rye (43% per hr) to triticale (27% per hr) to barley (20% per hr), and it exhibited remarkable variation between the genotypes of a single species. The maximal degradable CP fraction also differed between the species, but was overall very high (94%–99%). The lowest washout fraction (26%) and the highest variation in ED (77%–86% and 69%–80% for a passage rate of 5% and 8% per hr, respectively) were found in barley. The in situ uCP content (estimated using fOM) was lower for barley than for rye and triticale at ruminal passage rates of 5% and 8% per hr (barley: 157 g/kg DM at both passage rates; rye and triticale: 168 (at 5% per hr) and 169 (at 8% per hr) g/kg DM). In vitro estimations of uCP did not differ between the grain species and uCP estimated according to GfE was higher for triticale than for barley and rye, which did not differ. The low variation within a single grain species and the weak correlations between ruminal CP degradation and nutrient concentrations suggested that differentiation of ED and uCP between the genotypes of a single grain species is not necessary.

A screening study was conducted to investigate the nutrient composition, anti-nutritional factors, in vitro gas (GP) and methane (CH4) production of leaves and whole pods in tropical multipurpose trees (MPTs). The results indicated that the highest CP (296 g/kg DM) was found in Moringa stenopetala leaves followed by Acacia abysinica (277 g/kg DM), Millettia ferruginea (264 g/kg DM), Prosopis juliflora (261 g/kg DM) and Moringa oleifera (256 g/kg DM). In whole pods, the CP ranged from 172 in M. ferruginea to 191 g/kg DM in M. stenopetala. The starch in M. stenopetala, P. juliflora and Chamaecytisus palmensis leaves was 44.2, 28.8 and 24.4 g/kg DM, respectively. Leaves of Cajanus cajan had the highest concentrations of valine, isoleucine, leucine, phenylalanine, lysine and threonine. The highest concentration of total and tannin phenols were observed in leaves of A. nilotica while P. juliflora leaves had the lowest. Leaves of M. oleifera had higher total phenols and soluble condensed tannins than those of M. stenopetala. The in vitro GP were (P

An in vitro assay was modified to study the disappearance of inositol hexakisphosphate (InsP6 ) and the formation of lower inositol phosphate (InsP) isomers in the poultry digestive tract, and three experiments investigated the influence of diets with different ingredients and additives. Using the poultry diet as a matrix, the assay simulated the conditions (e.g. pH, temperature, proteolytic enzymes, water content, and retention time) of the crop, stomach, and small intestine, and extraction and analysis of InsP isomers were immediately conducted.; Results: The assay produced highly reproducible results with coefficients of variation ≤10% for an InsP isomer concentration ≥0.4 µmol g-1 DM (n = 3), and it was sensitive to the factors that varied in the three experiments.; Conclusion: The described assay is a suitable tool that can be used to screen feed enzymes and to investigate the effects of supplements in the absence of endogenous phytases. The ease of handling and high reproducibility of the assay indicated that the assay is a rapid and feasible method that can be used to examine the degradation pathway of phytate in feed under gastrointestinal conditions. © 2017 Society of Chemical Industry.; © 2017 Society of Chemical Industry.

Interest in amino acid digestibility of feed ingredients for poultry has been keen during the past decade. It is now acknowledged that digestibility determined at the terminal ileum is a better measure of amino acid absorption by the poultry. There had been a proliferation of publications on ileal amino acid digestibility values of range of feed ingredients, but wide variations seen in the published values remain a major concern to the end-users. In addition to the inherent ingredient variation, differences in assay methodology employed in laboratories are important contributing factors, highlighting the need for a consensus standard methodology to determine ileal amino acid digestibility. Two collaborative studies, involving five research stations, were initiated with this aim. In Study 1, maize and rapeseed meal were assayed, and pronounced variations in the ileal amino acid digestibility of these two ingredients were observed when the assay was conducted using station protocols, which differed in assay procedures. Use of a common agreed protocol in Study 2, in which a maize-soybean meal diet was assayed, completely eliminated the variation among research stations in apparent amino acid digestibility estimates. Based on these results, a consensus assay procedure for the determination of apparent ileal amino acid digestibility in feed ingredients for growing birds is proposed. It is hoped that this exercise will enable better comparison of data generated across research stations.

Two experiments (Exp.) with ileally cannulated growing barrows were conducted. The concentrations of positional inositol phosphate (InsP) isomers in ileal digesta and feces were determined, as well as the prececal and total tract phytate (InsP6) hydrolysis, and digestibility of dry matter, P, Ca, nitrogen, and gross energy. Prececal amino acid (AA) digestibility and digestive enzyme activities in ileal digesta were also studied. In both Exp., pigs had an initial body weight (BW) of 28 kg and were completely randomized to a Double Latin Square Design with eight pigs, four diets, and three periods of 12 d each. Feces and ileal digesta were collected for 5 d and 2 d, respectively. Pigs were housed individually in stainless steel metabolic units. Water was available ad libitum and feed was provided two times daily at an amount of 4% of mean BW. In Exp. 1, pigs received a corn–soybean meal (SBM)-based diet that was supplemented with 0, 750, 1,500, or 3,000 FTU of a microbial phytase/kg diet. In Exp. 2, pigs were allotted to a 2 × 2 arrangement of diets based on corn and SBM or an SBM-rapeseed cake (RSC) mix and phytase supplementation at 0 or 1,500 FTU/kg of diet. In ileal digesta of pigs fed without the phytase supplement, the dominating InsP isomers beside InsP6 were InsP5 isomers. The InsP pattern in ileal digesta changed with the inclusion of microbial phytase in both Exp., as there was a remarkable increase in Ins(1,2,5,6)P4 concentration (P < 0.001). In both Exp., the myo-inositol concentration in ileal digesta was greater upon phytase addition (P < 0.001). Without phytase supplementation, prececal and total tract P digestibility were low, whereas hardly any InsP6 was excreted in feces. There was no difference between prececal and total tract P digestibility values. For most AA studied in Exp. 2, prececal digestibility was lower (P < 0.01) when the diet contained RSC. However, phytase supplementation did not significantly affect prececal AA digestibility in both Exp. The present study showed that InsP6 disappearance by the end of the ileum can be increased up to around 90% in SBM- and SBM–RSC-based diets when microbial phytase is supplemented, but prececal P digestibility hardly exceeded 60%. The study confirms that pigs cannot benefit from a remarkable InsP6 degradation in the hindgut.

In this study, we aimed to investigate the ileum digesta of a large cohort of Japanese quail fed the same diet, with similar environmental conditions. We also address how P utilization (PU), Ca utilization (CaU), and bird performance (feed intake (FI), feed conversion (FC), and body weight gain (BWG)) modify intestinal microbiota of male and female quail. Despite the great number of samples analyzed (760), a core microbiome was composed of five bacteria. The Unc. Lactobacillus, Unc. Clostridaceae 1, Clostridium sensu stricto, Escherichia coli, and Streptococcus alactolyticus were detected in all samples and contributed to more than 70% of the total community. Depending on the bird predisposition for PU, CaU, FI, BWG, and FC, those species were present in higher or lower abundances. There was a significant gender effect on the ileal microbial community. While females had higher abundances of Lactobacillus, males were more colonized by Streptococcus alactolyticus. The entire cohort was highly colonized by Escherichia coli (8%&ndash, 15%), an enteropathogenic bacteria. It remains unclear, if microbiota composition followed the mechanisms that caused different PU, CaU, FI, FC, and BWG or if the change in microbiota composition and function caused the differences in PU, CaU, and performance traits.

Background There is good evidence for a substantial endogenous phytase activity originating from the epithelial tissue or the microbiota resident in the digestive tract of broiler chickens. However, ionophore coccidiostats, which are frequently used as feed additives in broiler diets to prevent coccidiosis, might affect the bacterial composition and the abundance of phytase producers in the gastrointestinal tract. The aim of the present study was to investigate whether supplementation of a frequently used mixture of the coccidiostats Narasin and Nicarbazin alone or together with a phytase affects microbiota composition of the digestive tract of broiler chickens, characteristics of phytate breakdown in crop and terminal ileum, and precaecal phosphorus and crude protein digestibility. Results Large differences in the microbial composition and diversity were detected between the treatments with and without coccidiostat supplementation. Disappearance of myo-inositol 1,2,3,4,5,6-hexakis(dihydrogen phosphate) (InsP6) in the digestive tract, precaecal P digestibility, inorganic P in blood serum, and the concentration of inositol phosphate isomers in the crop and ileum digesta were significantly affected by phytase supplementation, but not by coccidiostat supplementation. Crude protein digestibility was increased by coccidiostat supplementation when more phosphate was available. Neither microbial abundance and diversity nor any other trait measured at the end of the experiment was affected by coccidiostat when it was only supplemented from day 1 to 10 of age. Conclusions The coccidiostats used herein had large effects on overall microbiota composition of the digestive tract. The coccidiostats did not seem to affect endogenous or exogenous phytase activity up to the terminal ileum of broiler chickens. The effects of phytase on growth, phosphorus digestibility, and myo-inositol release were not altered by the presence of the coccidiostats. The effects of phytase and coccidiostats on nutrient digestibility can be of significant relevance for phosphorus and protein-reduced feeding concepts if confirmed in further experiments. Electronic supplementary material The online version of this article (10.1186/s42523-019-0006-2) contains supplementary material, which is available to authorized users.

Spelt has gained growing interest in Europe in human and animal nutrition. Data on the chemical composition of spelt and its variations, especially their nutritional value for ruminants, are scarce. Therefore, hulled kernels, dehulled kernels and hulls of six spelt cultivars grown on three different locations were analysed for their chemical composition and nutritive value for ruminants using the Hohenheim Gas Test. Most of the analysed constituents varied considerably and were significantly affected by the cultivars or location, or both. Hulled spelt and spelt kernels of more recent cultivars had higher starch and energy concentrations and lower concentrations of crude protein and fibre fractions than those of traditional cultivars. Significant differences between cultivars were found in the energy values for ruminants for hulled spelt but not for fractionated kernels. Spelt hulls of different cultivars and locations showed a high variation in chemical composition with overall high concentrations of fibre fractions and crude ash. The nutritive values for ruminants of hulled spelt and spelt kernels were similar to those of oats and wheat respectively. Pure spelt hulls cannot be recommended for use in ruminant feeding because of their high concentrations of fibre fractions and crude ash. However, when some part of the kernel (~20%) or small kernels remain with the hull in the dehulling process, the resulting hull fraction has a metabolizable energy value for ruminants that is similar to that of wheat straw.

Simple Summary Mitochondria are commonly known as “the powerhouse of the cell”, influencing the fitness, lifespan and metabolism of eukaryotic organisms. In our study we examined mitochondrial and nuclear genomic diversity in two high yielding strains of laying hens. We tested if the mitochondrial genome affects functional traits such as body weight and phosphorus utilization. We discovered a surprisingly low mitochondrial genetic diversity and an unequal distribution of the haplotypes among both strains, leading to limitations of robust links to phenotypic traits. In contrast, we found similar levels of nuclear genome diversity in both strains. Our study explores the potential influence of the mitochondrial genome on phenotypic traits and thus contributes to a better understanding of the function of this organelle in laying hens. Further, we focus on its usefulness as a genetic marker, which is often underestimated in breeding approaches, given the different inheritance mechanism compared to the nuclear genome. Abstract Mitochondria are essential components of eukaryotes as they are involved in several organismic key processes such as energy production, apoptosis and cell growth. Despite their importance for the metabolism and physiology of all eukaryotic organisms, the impact of mitochondrial haplotype variation has only been studied for very few species. In this study we sequenced the mitochondrial genome of 180 individuals from two different strains of laying hens. The resulting haplotypes were combined with performance data such as body weight, feed intake and phosphorus utilization to assess their influence on the hens in five different life stages. After detecting a surprisingly low level of genetic diversity, we investigated the nuclear genetic background to estimate whether the low mitochondrial diversity is representative for the whole genetic background of the strains. Our results highlight the need for more in-depth investigation of the genetic compositions and mito-nuclear interaction in individuals to elucidate the basis of phenotypic performance differences. In addition, we raise the question of how the lack of mitochondrial variation developed, since the mitochondrial genome represents genetic information usually not considered in breeding approaches.

The objective of this ring test was to investigate the prececal phosphorus (P) digestibility of soybean meal (SBM) in broiler chickens using the trial protocol proposed by the World's Poultry Science Association. It was hypothesized that prececal P digestibility of SBM determined in the collaborating stations is similar. Three diets with different inclusion levels of SBM were mixed in a feed mill specialized in experimental diets and transported to 17 collaborating stations. Broiler chicks were raised on commercial starter diets according to station-specific management routine. Then they were fed the experimental diets for a minimum of 5 d before content of the posterior half of the ileum was collected. A minimum of 6 experimental replicates per diet was used in each station. All diets and digesta samples were analyzed in the same laboratory. Diet, station, and their interaction significantly affected (P < 0.05) the prececal digestibility values of P and calcium of the diets. The prececal P digestibility of SBM was determined by linear regression and varied among stations from 19 to 51%, with significant differences among stations. In a subset of 4 stations, the prececal disappearance of myo- inositol 1,2,3,4,5,6-hexakis (dihydrogen phosphate)-P; InsP6-P) also was studied. The prececal InsP6-P disappearance correlated well with the prececal P digestibility. We hypothesized that factors influencing InsP6 hydrolysis were main contributors to the variation in prececal P digestibility among stations. These factors were probably related to the feeding and housing conditions (floor pens or cages) of the birds in the pre-experimental phase. Therefore, we suggest that the World's Poultry Science Association protocol for the determination of digestible P be should extended to the standardization of the pre-experimental period. We also suggest that comparisons of P digestibility measurements among studies are made only with great caution until the protocol is more refined. info:eu-repo/semantics/publishedVersion

BACKGROUND The influence of nitrogen fertilisation and genotype on the amino acid (AA) digestibility of triticale grain was investigated in caecectomised laying hens. Three genotypes, Grenado, EAW6002 and Lasko, were cultivated with and without nitrogen fertilisation at the end of the heading stage. The six triticale variants as well as a basal diet were each used to feed seven laying hens in a 7 × 7 Latin square design. RESULTS Nitrogen fertilisation influenced the digestibility of Cys, Glu, Phe and Ser in some triticale genotypes and reduced Ala, Ile, Lys, Met and Val digestibility in all genotypes (P < 0.05). Nitrogen fertilisation increased the concentration of all AAs in the grain. Consequently, the concentration of digestible AAs in the grains was increased for most AAs upon nitrogen fertilisation. Overall, Lys had the lowest digestibility, whereas that of Glu and Pro was the highest. For the triticale genotypes, the level of AA digestibility was highest for EAW6002 followed by Lasko and Grenado, with significant differences (P < 0.05) between genotypes for some but not all AAs. CONCLUSION The results indicated that the accuracy of the digestible AA supply for hen feeding might benefit from considering fertilisation and genotype-specific digestibility data in feed formulation. © 2016 Society of Chemical Industry.

Summary The ruminal disappearance of phytate phosphorus (InsP6-P) from maize grain and rapeseed meal (RSM) was determined in two in vitro studies. In experiment 1, two diets differing in phosphorus (P) and InsP6-P concentration were fed to the donor animals of rumen fluid (diet HP: 0.49% P in dry matter, diet LP: 0.29% P). Maize grain and RSM were incubated in a rumen fluid/saliva mixture for 3, 6, 12 and 24 h. In experiment 2, a diet similar to diet HP was fed, and the rumen fluid was mixed with artificial saliva containing 120 mg inorganic P/l (Pi) or no inorganic P (P0). Maize grain and RSM were incubated with either buffer for 3, 6, 12 and 24 h. Total P (tP) and InsP6 concentration were analysed in the fermenter fluids and feed residues. The disappearance of InsP6-P from maize was completed after 12 h of incubation in both experiments. From RSM, 93% (diet LP) and 99% (diet HP) of the InsP6-P in experiment 1 and 80% (Pi) and 89% (P0) in experiment 2 had disappeared after 24 h of incubation. InsP6-P disappearance was higher when diet HP was fed (maize: 3 and 6 h; RSM: 6 and 24 h of incubation) and when rumen fluid was mixed with buffer P0 (maize: 6 h; RSM: 12 and 24 h of incubation). InsP6-P concentration in the fermenter fluids was higher for maize, but no accumulation of InsP6-P occurred, indicating a prompt degradation of soluble InsP6. These results confirmed the capability of rumen micro-organisms to efficiently degrade InsP6. However, differences between the feedstuffs and diet composition as well as the presence of inorganic P in the in vitro system influenced the degradation process. Further studies are required to understand how these factors affect InsP6 degradation and their respective relevance in vivo.

The objectives of this meta-analysis were to determine to which extent phosphorus (P) digestibility and digestible P concentration in pig diets were increased by phytase supplementation and to quantify factors that potentially influence effects of phytase supplementation. A data set with a total of 547 data lines was compiled from 88 experiments published in 74 peer-reviewed papers between 2007 and April 2019. An exponential model was determined as more suitable to describe the response of P digestibility to phytase supplementation than a polynomial model. Phytase supplementation increased P digestibility by 25.6 percentage points (standard error (SE) = 1.54) to a plateau at 64.9% (SE = 1.82). The digestible P concentration was increased by phytase supplementation in the order of 1.01 g/kg (SE = 0.102) to a plateau at 2.62 g/kg (SE = 0.122). Goodness-of-fit criteria were R2 = 0.780 and root mean square error = 7.55% for P digestibility, and R2 = 0.691 and root mean square error = 0.48 g/kg for digestible P concentration. Consideration of further factors such as mineral P supplementation (yes or no), ad libitum vs. restrictive feeding, mixed diets vs. single feed ingredients, sex and age of pigs did not increase the accuracy of prediction in this data set. Some of these traits exhibited responses, but they likely are artefacts generated through the imbalanced structure of the data set. Effects of dietary total P, phytate (InsP6), InsP6-P to total P ratio, and Ca on the effect of supplemented phytase were not quantifiable. The present meta-analysis showed that responses to phytase supplementation can be well predicted although variation in P digestibility and digestible P concentration in the data set was high. Overall, predicted effects of phytase on P digestibility well corresponded to predictions made 25 years ago.

Phosphorus is an essential mineral for all living organisms and a limited resource worldwide. Variation and heritability of phosphorus utilization (PU) traits were observed, indicating the general possibility of improvement. Molecular mechanisms of PU, including host and microbial effects, are still poorly understood. The most promising molecules that interact between the microbiome and host are microRNAs. Japanese quail representing extremes for PU were selected from an F2 population for miRNA profiling of the ileal tissue and subsequent association with mRNA and microbial data of the same animals. Sixty-nine differentially expressed miRNAs were found, including 21 novel and 48 known miRNAs. Combining miRNAs and mRNAs based on correlated expression and target prediction revealed enrichment of transcripts in functional pathways involved in phosphate or bone metabolism such as RAN, estrogen receptor and Wnt signaling, and immune pathways. Out of 55 genera of microbiota, seven were found to be differentially abundant between PU groups. The study reveals molecular interactions occurring in the gut of quail which represent extremes for PU including miRNA-16-5p, miR-142b-5p, miR-148a-3p, CTDSP1, SMAD3, IGSF10, Bacteroides, and Alistipes as key indicators due to their trait-dependent differential expression and occurrence as hub-members of the network of molecular drivers of PU.

Phosphorus (P) is an essential component for all living beings. Low P diets prompt phenotypic and molecular adaptations to maintain P homeostasis and increase P utilization (PU). Knowledge of the molecular mechanisms of PU is needed to enable targeted approaches to improve PU efficiency and thus lower P excretion in animal husbandry. In a previous population study, Japanese quail were subjected to a low P diet lacking mineral P and exogenous phytase. Individual PU was determined based on total P intake and excretion. A subset of 20 extreme siblings discordant for PU was selected to retrieve gene expression patterns of ileum (n = 10 per PU group). Sequencing reads have been successfully mapped to the current Coturnix japonica reference genome with an average mapping rate of 86%. In total, 640 genes were found to be differentially abundant between the low and high PU groups (false discovery rate &le, 0.05). Transcriptional patterns suggest a link between improved PU and mitochondrial energy metabolism, accelerated cell proliferation of enterocytes, and gut integrity. In assessing indicators of the efficient use of macro- and micronutrients, further research on turnover and proliferation rates of intestinal cells could provide an approach to improve P efficiency in poultry species.

The present study assessed effects of diets containing varying calcium-phosphorus (CaP) concentration and fermentable substrates on digestibility of diets, intestinal microbiota and immune system using 32 crossbred pigs (initial BW 54.7 kg). In a 2 × 2 factorial arrangement, pigs were fed either a corn-soybean meal (CSB) or corn-field pea (CFP) diet with either low [-] (4.4 g Ca/kg; 4.2 g total P/kg) or high [+] (8.3 g Ca/kg; 7.5 g total P/kg; supplemented with monocalcium phosphate) CaP content for a period of 9 weeks. In week 8, blood samples were taken, and at the end of the trial, all pigs were euthanized to collect digesta and mesenteric lymphoid tissue. Apparent total tract digestibility (ATTD) of P was greater (p < 0.05) for pigs fed the CaP+ and CFP diets than CaP- and CSB diets. The myo-inositol 1,2,3,4,5,6-hexakis (dihydrogen phosphate) (InsP6 ) concentration in jejunal digesta was higher (p < 0.05) for CaP+ than in CaP- fed pigs. In addition, caecal and faecal InsP5 isomer concentration were greater (p < 0.05) for CSB than CFP diets. In the caecum, gene copy numbers of saccharolytic bacteria, such as Eubacterium rectale and Roseburia spp., as well as SCFA concentration were higher (p < 0.05) for CaP+ than CaP- diets. In particular, innate immune cell numbers, such as natural killer cells, dendritic cells, monocytes and neutrophils, were greater (p < 0.05) for CaP+ than CaP- fed pigs. Diets high in CaP resulted in higher abundance of potential beneficial bacteria and might promote the first line of defence enhancing the activation of the cellular adaptive immune response, thereby possibly decreasing the risk for intestinal disturbances. These results strongly suggest that both, CaP supply and dietary ingredients differing in fermentability, may beneficially affect gut health through increase in SCFA-producing bacteria and/or bacteria with anti-inflammatory properties.

The chemical composition of 16 microalgae products of four genera, Arthrospira (n = 2), Chlorella (n = 8), Nannochloropsis (n = 4) and Phaeodactylum (n = 2), was assayed to evaluate the intra- and inter-genera variation of nutrient profiles of commercial microalgae products. Crude protein was the main component in all genera, followed by ether extract and crude ash. Mean crude protein concentrations were 690, 502, 431 and 446 g/kg dry matter, and mean ether extract concentrations were 63, 157, 188 and 113 g/kg dry matter for Arthrospira, Chlorella, Nannochloropsis and Phaeodactylum respectively. However, there was considerable inter- and intra-genera variation. The concentration of α-linked glucose was low (0-143 g/kg dry matter). There was high variation between and within genera in the crude ash concentration (22-237 g/kg dry matter), which was also observed for the mineral composition. In contrast to the crude protein concentration, the amino acid composition of the protein (g amino acid/16 g N) was less variable. The investigated samples possessed high concentrations of Glx, Asx and Leu, and low concentrations of Cys and Met. The mean concentration of non-protein nitrogen compounds was highest in Phaeodactylum (110 g/kg dry matter) and lowest in Nannochloropsis (47 g/kg dry matter) products, and as with proximate nutrients, high variability between and within genera was observed. In vitro crude protein digestibility varied between 54% (non-cell-disrupted Nannochloropsis) and 84% (cell-disrupted Chlorella). Inositol phosphate isomers were not detectable in any sample (concentration

A regression approach was applied to determine the influence of feed provisioning prior to digesta sampling on precaecal (pc) amino acid (AA) digestibility in broiler chickens. Soybean meal was used as an example test ingredient. Five feed-provisioning protocols were investigated, four with restricted provision and one with ad libitum provision. When provision was restricted, feed was provided for 30 min after a withdrawal period of 12 h. Digesta were sampled 1, 2, 4 and 6 h after feeding commenced. A diet containing 300 g maize starch/kg was prepared. Half or all the maize starch was replaced with soybean meal in two other diets. Average pc digestibility of all determined AA in the soybean meal was 86% for the 4 and 6-h protocols and 66% and 60% for the 2 and 1-h protocols, respectively. Average pc AA digestibility of soybean meal was 76% for ad libitum feed provision. Feed provisioning also influenced the determined variance. Variance in digestibility ranked in magnitude 1 h ad libitum 2 h 6 h 4 h for all AA. Owing to the considerable influence of feed-provisioning protocols found in this study, comparisons of pc AA digestibility between studies applying different protocols prior to digesta sampling must be treated with caution. Digestibility experiments aimed at providing estimates for practical feed formulation should use feed-provisioning procedures similar to those used in practice.

Compared to grass silage (GS)-, corn silage (CS)-based diets appear to increase the efficiency of microbial protein synthesis (EMPS) in the rumen. Opposite results for the EMPS obtained in vitro have raised the question of whether an inadequate supply of amino N for microbes might explain the low EMPS. We examined the effects of supplementation with different N sources in CS on the EMPS and microbial populations in vitro. GS and CS were used as substrates for in vitro incubation. CS was non-supplemented or supplemented with urea, mixed amino acids (AA), peptone, or protein to adjust the N content to that of GS. Degradation of organic matter (OM) and crude protein (CP) revealed a positive effect of all N supplements, except protein. Additionally, N supplementation increased fiber degradation of CS. Peptone primarily stimulated hemicellulolytic activity and urea stimulated cellulolytic activity. The EMPS of CS was improved by all N supplements, with peptone and urea exhibiting the highest increase (57% and 54%, respectively), followed by AA mix (40%) and protein (11%) compared to that of CS alone (111 g microbial CP kg−1 fermented OM). However, the level of EMPS detected with GS (200 g microbial CP kg−1 fermented OM) was not achieved. Protozoal 18S rRNA gene copy numbers were negatively correlated with the EMPS, whereas no correlation was found between total bacteria and the EMPS. A stimulating effect of urea, AA mix, and peptone was detected for Ruminococcus albus and Prevotella bryantii, whereas Fibrobacter succinogenes was inhibited by N supplementation. This indicated that neither the amount of available N nor the N source was the only limiting factor in the low EMPS values of CS in vitro. Information is also provided on the stimulating effects of different N sources on several microbial species in mixed rumen culture.

Magnesium has essential functions in cellular metabolism and bone development. Its actions are closely linked to calcium and phosphorus, making the achievement of the right proportion of these elements in diets an important issue in poultry nutrition. The magnesium requirement of poultry has rarely been studied and most studies conducted are more than 35 years old. Despite the fact that magnesium is adequately present in most plant-based diets, supplemental magnesium may positively affect poultry meat quality and body weight at certain developmental stages. However, excessive dietary magnesium could influence calcium and phosphorus availability and metabolism through different mechanisms. Understanding the effects of supplemental magnesium on the availability and metabolism of other dietary constituents and vice versa is important for formulating balanced diets and achieving maximal performance in poultry. Here we review this complex, insufficiently explored issue.

A study was conducted to assess the nutrient composition, in vitro gas production (GP) characteristics and methane (CH4) production potential of some common Ethiopian grass and legume forages. Crude protein (CP) concentration was lower in grasses than in legumes, while the reverse was observed for neutral detergent fiber (aNDFom) and acid detergent fiber (ADFom) concentrations. Within the 9 grasses tested, Cynodon dactylon had the highest CP concentration (187 g/kg DM), while Panicum coloratum and Cenchrus ciliaris had the lowest (70 and 82 g/kg DM, respectively) values. Chloris gayana contained the highest aNDFom (651 g/kg DM) concentration, while Avena sativa had the lowest (484 g/kg DM). Among the 3 legumes tested, Vicia sativa had the highest CP concentration (346 g/kg DM). The aNDFom and ADFom concentrations were highest in V. sativa and lowest in Medicago sativa. In grasses, Brachiaria mutica had the highest calcium, magnesium, iron and manganese concentrations, while in legumes the highest concentrations of phosphorus, potassium and zinc were observed in V. sativa. Methane production was generally higher (P

The structure and function of the microbiome inhabiting the rumen are, amongst other factors, mainly shaped by the animal's feed intake. Describing the influence of different diets on the inherent community arrangement and associated metabolic activities of the most active ruminal fractions (bacteria and archaea) is of great interest for animal nutrition, biotechnology, and climatology. Samples were obtained from three fistulated Jersey cows rotationally fed with corn silage, grass silage or grass hay, each supplemented with a concentrate mixture. Samples were fractionated into ruminal fluid, particle-associated rumen liquid, and solid matter. DNA, proteins and metabolites were analyzed subsequently. DNA extracts were used for Illumina sequencing of the 16S rRNA gene and the metabolomes of rumen fluids were determined by 500 MHz-NMR spectroscopy. Tryptic peptides derived from protein extracts were measured by LC-ESI-MS/MS and spectra were processed by a two-step database search for quantitative metaproteome characterization. Data are available via ProteomeXchange with the identifier PXD006070. Protein- and DNA-based datasets revealed significant differences between sample fractions and diets and affirmed similar trends concerning shifts in phylogenetic composition. Ribosomal genes and proteins belonging to the phylum of Proteobacteria, particularly Succinivibrionaceae, exhibited a higher abundance in corn silage-based samples while fiber-degraders of the Lachnospiraceae family emerged in great quantities throughout the solid phase fractions. The analysis of 8163 quantified bacterial proteins revealed the presence of 166 carbohydrate active enzymes in varying abundance. Cellulosome affiliated proteins were less expressed in the grass silage, glycoside hydrolases appeared in slightest numbers in the corn silage. Most expressed glycoside hydrolases belonged to families 57 and 2. Enzymes analogous to ABC transporters for amino acids and monosaccharides were more abundant in the corn silage whereas oligosaccharide transporters showed a higher abundance in the fiber-rich diets. Proteins involved in carbon metabolism were detected in high numbers and identification of metabolites like short-chain fatty acids, methylamines and phenylpropionate by NMR enabled linkage between producers and products. This study forms a solid basis to retrieve deeper insight into the complex network of microbial adaptation in the rumen.

Plant and microbial phytases present in raw materials can cause a dephosphorylation of phytate (myo-inositol hexakisphosphate) (InsP6)) during food processing resulting in a broad range of different myo-inositol phosphates such as pentakisphosphate (InsP5) and tetrakisphosphate (InsP4) in foods. Here, we investigated whether the human intestinal epithelium is able to dephosphorylate myo-inositol phosphates (InsP6, InsP5-, InsP4-, InsP3-isomers) using an in vitro model with differentiated human Caco-2 cells cultured on semipermeable inserts. Incubation of InsP6 and an InsP5-isomer with cells for 3 h showed no dephosphorylation of both InsPs. Treatment of cells with a mixture of different InsP4-isomers, however, caused a formation of about 3.5% of an InsP3-isomer (Ins(1,5,6)P3) and treatment with a mixture of different InsP3-isomers caused about 20% formation of InsP2-isomers, respectively. Thus, human intestinal cells can contribute to the dephosphorylation of myo-inositol phosphates of partly deph...

Phytase supplementation in broiler diets is a common practice to improve phosphorus (P) availability and to reduce P loss by excretion. An enhanced P availability, and its concomitant supplementation with calcium (Ca), can affect the structure of the microbial community in the digestive tract of broiler chickens. Here, we aim to distinguish the effects of mineral P, Ca, and phytase on the composition of microbial communities present in the content and the mucosa layer of the gastrointestinal tract (GIT) of broiler chickens. Significant differences were observed between digesta and mucosa samples for the GIT sections studied (p = 0.001). The analyses of 56 individual birds showed a high microbial composition variability within the replicates of the same diet. The average similarity within replicates of digesta and mucosa samples across all diets ranged from 29 to 82% in crop, 19–49% in ileum, and 17–39% in caeca. Broilers fed with a diet only supplemented with Ca had the lowest body weight gain and feed conversion values while diets supplemented with P showed the best performance results. An effect of each diet on crop mucosa samples was observed, however, similar results were not obtained from digesta samples. Microbial communities colonizing the ileum mucosa samples were affected by P supplementation. Caeca-derived samples showed the highest microbial diversity when compared to the other GIT sections and the most prominent phylotypes were related to genus Faecalibacterium and Pseudoflavonifractor, known for their influence on gut health and as butyrate producers. Lower microbial diversity in crop digesta was linked to lower growth performance of birds fed with a diet only supplemented with Ca. Each diet affected microbial communities within individual sections, however, no diet showed a comprehensive effect across all GIT sections, which can primarily be attributed to the great variability among replicates. The substantial community differences between digesta and mucosa derived samples indicate that both habitats have to be considered when the influence of diet on the gut microbiota, broiler growth performance, and animal health is investigated.

The chicken gastrointestinal tract (GIT) harbours a complex microbial community, involved in several physiological processes such as host immunomodulation and feed digestion. For the first time, the present study analysed dietary effects on the protein inventory of the microbiome in crop and ceca of broilers. We performed quantitative label-free metaproteomics by using 1-D-gel electrophoresis coupled with LC-MS/MS to identify the structural and functional changes triggered by diets supplied with varying amount of mineral phosphorous (P) and microbial phytase (MP). Phylogenetic assessment based on label-free quantification (LFQ) values of the proteins identified Lactobacillaceae as the major family in the crop section regardless of the diet, whereas proteins belonging to the family Veillonellaceae increased with the P supplementation. Within the ceca section, proteins of Bacteroidaceae were more abundant in the P-supplied diets, whereas proteins of Eubacteriaceae decreased with the P-addition. Proteins of the Ruminococcaceae increased with the amount of MP while proteins of Lactobacillaceae were more abundant in the MP-lacking diets. Classification of the identified proteins indicated a thriving microbial community in the case of P and MP supplementation, and stressed microbial community when no P and MP were supplied. Data are available via ProteomeXchange with identifier PXD003805.