Effect of early dietary energy restriction and phosphorus level on subsequent growth performance, intestinal phosphate transport, and AMPK activity in young broilers

Interaction between energy level and starch:fat ratio on intestinal energy metabolism of layer pullets

During the growing period, the gastrointestinal tract of layer pullets is not yet well developed and may be susceptible to dietary energy level. The energy level and composition might impact the intestinal energy metabolism of layer pullets. To test this hypothesis, a total of 480 "Jing Tint 6" layer pullets were used in an 8-week study and allocated to 4 groups, each consisting of 8 replicates, with 15 birds per replicate. Pullets were treated with low or high starch:fat ratios (LS, 10:1; HS, 20:1) in a 2 × 2 factorial arrangement with regular energy (RE, 11.85 and 11.68 MJ/kg for birds from 6 to 10 weeks of age and 11-14 weeks of age, respectively) or low energy (LE, 0.55 MJ/kg lower than RE) levels. A significant interaction (P < 0.05) showed that HS increased glandular stomach weight and the jejunal villus length to crypt depth ratio (VCR) in LE diets, but decreased these parameters in RE diets. Dietary energy reduction impaired energy metabolism in the ileum (P < 0.05) mainly via decreasing the gene expression of enzymes involved in the tricarboxylic acid (TCA) cycle (α-ketoglutarate dehydrogenase complex [α-KGDH]; isocitrate dehydrogenase (NAD (+) [IDH] catalytic; citrate synthase [CS]) and adenosine triphosphate (ATP) synthesis, reducing contents of phosphoenolpyruvate (PEP) and adenylate energy charges (AEC) and down-regulating the adenosine monophosphate-activated protein kinase (AMPK) pathway. HS stimulated AMPKα phosphorylation, increased protein abundance of peroxisome proliferator activated-receptor gamma coactivator 1α (PGC1α) and improved contents of amino acids (aspartate, glutamate, glutamine, alanine and threonine) and malate in the ileum regardless of energy levels (P < 0.05). By an interaction (P < 0.05), the transition from LS to HS diets up-regulated ileal gene expression of AMPKα1 and decreased content of adenosine monophosphate (AMP), accompanied by higher AEC but only in birds fed with LE diets. Collectively, these results suggest that low energy feeding may not be enough for maintaining intestinal energy homeostasis in layer pullets and emphasizes the importance of a relatively high starch:fat ratio in restoring energy metabolism in the ileum.

Effects of dietary metabolizable energy level on hepatic lipid metabolism and cecal microbiota in aged laying hens

Lipid metabolic capacity, feed utilization, and the diversity of gut microbiota are reduced in the late laying stage for laying hens. This experiment aimed to investigate the effects of different levels of dietary metabolizable energy (ME) on hepatic lipid metabolism and cecal microbiota in late laying hens. The 216 Peking Pink laying hens (57-wk-old) were randomly assigned to experimental diets of 11.56 (HM = high ME), 11.14 (MM = medium ME), or 10.72 (LM = low ME) MJ of ME/kg, with each dietary treatment containing 6 replicates per group and 12 chickens per replicate. The HM group showed higher triglyceride (TG), total cholesterol (T-CHO), and low-density lipoprotein cholesterol (LDL-C) concentrations in the liver compared with the LM group; second, the HM group showed higher TG concentration and the LM group showed lower T-CHO concentration compared with MM group; finally, the HM group showed a lower hepatic lipase (HL) activity compared with the MM and LM groups (P < 0.05). There was a significant difference in the microbial community structure of the cecum between the HM and MM groups (P < 0.05). The decrease of dietary ME level resulted in a gradual decrease relative abundance of Proteobacteria. At the genus level, beneficial bacteria were significantly enriched in the LM group compared to the MM group, including Faecalibacterium, Lactobacillus, and Bifidobacterium, (linear discriminant analysis [LDA] >2, P <0.05). In addition, at the species level, Lactobacillus crispatus, Parabacteroides gordonii, Blautia caecimuris, and Lactobacillus johnsonii were significantly enriched in the LM group (LDA>2, P < 0.05). The HM group had a higher abundance of Sutterella spp. compared to the LM group (LDA>2, P <0.05). In conclusion, this research suggests that the reduction in dietary energy level did not adversely affect glycolipid metabolism or low dietary ME (10.72 MJ/kg). The findings can be helpful for maintaining intestinal homeostasis and increasing benefit for gut microbiota in late laying hens.

Potential for the development of Taraxacum mongolicum aqueous extract as a phytogenic feed additive for poultry

Introduction

Taraxacum mongolicum (TM) is a kind of medicinal and edible homologous plant which is included in the catalogue of feed raw materials in China. It is rich in polyphenols, flavonoids, polysaccharides and other active substances, and shows many benefits to livestock, poultry and aquatic products. The study aimed to assess the potential of TM aqueous extract (TMAE) as a substitute for poultry AGPs.

Methods

A total of 240 one-day-old Arbor Acker broilers were randomly assigned to four groups and fed a basal diet (Con) supplemented with 500, 1000, and 2000 mg/kg TMAE (Low, Medium, and High groups). The growth performance of the broilers was measured on day 21 and day 42. At the end of the trial, the researchers measured slaughter performance and collected serum, liver, spleen, ileum, and intestinal contents to investigate the effects of TMAE on serum biochemistry, antioxidant capacity, immune function, organ coefficient, intestinal morphology, flora composition, and short-chain fatty acids (SCFAs).

Results

The results showed that broilers treated with TMAE had a significantly higher average daily gain from 22 to 42 days old compared to the Con group. Various doses of TMAE resulted in different levels of improvement in serum chemistry. High doses increased serum alkaline phosphatase and decreased creatinine. TMAE also increased the antioxidant capacity of serum, liver, and ileum in broilers. Additionally, middle and high doses of TMAE enhanced the innate immune function of the liver (IL-10) and ileum (Occludin) in broilers. Compared to the control group, the TMAE treatment group exhibited an increase in the ratio of villi length to villi crypt in the duodenum. TMAE increased the abundance of beneficial bacteria, such as Alistipes and Lactobacillus, while reducing the accumulation of harmful bacteria, such as Colidextracter and Sellimonas. The cecum's SCFAs content increased with a medium dose of TMAE. Supplementing broiler diets with TMAE at varying doses enhanced growth performance and overall health. The most significant benefits were observed at a dose of 1000 mg/kg, including improved serum biochemical parameters, intestinal morphology, antioxidant capacity of the liver and ileum, immune function of the liver and ileum, and increased SCFAs content. Lactobacillus aviarius, norank_f_norank_o__Clostridia_UCG-014, and Flavonifractor are potentially dominant members of the intestinal microflora.

Conclusion

In conclusion, TMAE is a promising poultry feed additive and 1000 mg/kg is an effective reference dose.

Evaluation of sodium butyrate and nutrient concentration for broiler chickens

The relation between nutrition and intestinal health is a subject with an increasing interest in research, as nutritionists need knowledge about how formulation affects different parameters in the gastrointestinal tract (GIT). That is why 4 trials were conducted to evaluate the effect of nutrient concentration and a feed additive (sodium butyrate protected with sodium salts of palm fatty acid distillates (PSB, Gustor N'RGY produced by Norel S.A., Spain, dosed at 1 kg/t), on performance, diet digestibility, intestinal morphology, volatile fatty acid concentration (VFA) in the GIT and intestinal microbiota of broiler chickens, when fed diets with different energy and amino acids concentration. Control diets, C, with the recommended metabolizable energy (ME) and ideal amino acid (AA) composition; Reduction 1, R1, C – 60 kcal ME and – 2.3% AA and Reduction 2, R2, C – 120 kcal ME and – 4.6% AA) based on different feed ingredients (Corn Soy [CS] and Wheat Barley Soy (WBS) were formulated. All trials lasted 42 d. In trials 2 and 4, the nutrient dilution decreased performance of the animals. In all trials, PSB improved animal performance (growth or FCR), despite the different situations. In trials 1 and 4, animals receiving R1 diets and PSB showed similar performance to those receiving C diets without PSB. PSB improved Gross Energy metabolizability (69.94 vs. 72.55; P: 0.02). Nutrient concentration affected histology results in T2 (ileum) and T3 (jejunum); PSB showed effects in T2 (jejunum, ileum) and in T3 (jejunum). In T1, PSB affected VFA in duodenum, jejunum, and ileum, changing the profile depending on diet nutrient concentration. PSB altered microbiology in caecum of animals in T2. It can be concluded that the dilution of ME and AA concentration of the diet impairs animal performance, influences intestinal microbiota and affects intestinal histology. PSB improves animal performance, increases gross energy metabolizability, steers intestinal microbiota and alters VFA concentrations in the intestine. The addition of PSB may help the animal to counteract the negative effects of diluted diets.

Identification of the Key Molecular Drivers of Phosphorus Utilization Based on Host miRNA-mRNA and Gut Microbiome Interactions

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.

Ileal Transcriptome Profiles of Japanese Quail Divergent in Phosphorus Utilization

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 ≤ 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.

Effect of early neonatal development and delayed feeding post-hatch on jejunal and ileal calcium and phosphorus transporter genes expression in broiler chickens

Calcium (Ca) and phosphorus (P) are essential minerals involved in many biological processes including bone development and mineralization. Plasma concentration of both minerals is tightly regulated, and Ca and P homeostasis is maintained via intestinal absorption, bone storage and exchange, and renal reabsorption. In the current broiler production systems, chicks are deprived of food and water for up to 72 h due to uneven hatching, hatchery procedures, and transportation time to farms. Post-hatch (PH) feed delay results in lower body and organ weight, higher feed conversion ratio and mortality, and delayed PH growth and GIT development. Little is known about the effects of early neonatal development and delayed or immediate feeding PH on Ca and P transporters. Therefore, the aim of the present study was to characterize expression patterns of Ca and P transporter genes in small intestine during the first 2 wk PH in chickens fed immediately after hatch (FED) or subjected to 48 h delayed feeding (NOTFED). Expression of all Ca and P transporters in jejunum and ileum was significantly (P < 0.05) affected by age. Among Ca transporter genes, only mRNA expression of Calbidin D28k in jejunum and Ca sensing receptor (CaSR) in ileum were significantly (P < 0.05) affected by delay in feed access. For P transporter genes' expression, only P transporter type III (PIT1) mRNA was significantly affected by age, delay in feed access, and their interaction (P < 0.05). In summary, we have shown, for the first time, early developmental changes of Ca and P transporter genes in broiler chickens. Results suggest that an increase in gene expression of some of the transporters corresponds with the switch from yolk to high starch diet. Overall, our results can be helpful in better understanding of Ca and P homeostasis in broilers.