Efficient phosphorus utilization in poultry feeding to lessen the environmental impact of excreta

FGF23 level in poultry chicken, a systematic review and meta-analysis

Introduction: In vertebrates fibroblast growth factor 23 (FGF23) is a phosphate regulating hormone closely linked to calcium regulation by vitamin D and parathyroid hormone (PTH). Although phosphorus, calcium and vitamin D are important for poultry well-being, relatively little is known about their levels of FGF23. Our objective was to quantitatively estimate the blood FGF23 level in birds, and to examine its relationship to diet and blood levels of other components of phosphate and calcium homeostasis. Methods: A systematic search of Agricola, Embase and Medline identified 86 studies focused on FGF23 in birds, from which 12 manuscripts reporting data for 60 independent groups of chickens were included in the analysis. Results: FGF23 levels were 256 pg/ml (Confidence interval (CI): 215, 297) in broilers (39 datasets containing 435 birds), and 256 pg/ml (CI: 178, 339) in egg-laying hens (21 datasets containing 208 birds). FGF23 levels did not correlate with dietary phosphorus, calcium or vitamin D, or with plasma calcium or PTH. FGF23 levels demonstrated a trend to positively correlate with plasma phosphate and a strongly and positive correlation with plasma vitamin D. Discussion: This study provides normative estimates of FGF23 levels in poultry birds and new insights into the regulation of calcium and phosphate homeostasis.

Efficacy of Various Feed Additives on Performance, Nutrient Digestibility, Bone Quality, Blood Constituents, and Phosphorus Absorption and Utilization of Broiler Chickens Fed Low Phosphorus Diet

The present trial was designed to assess the effect of phytase, multi-strain probiotic, Saccharomyces cerevisiae, and fumaric acid on performance, nutrient digestibility, bone physical parameters and mineralization, blood constituents, bone and gut histomorphology, and duodenal phosphorus transporter genes of broiler chickens fed a decreased non-phytate phosphorus (nPP) diet for 5 weeks. A total of 480 broiler chickens were allotted to six dietary groups and eight replicates each: (1) positive control diet with recommended levels of nPP (PC; 0.48, 0.44, and 0.41% in the three feeding phases); (2) negative control diet with a decreased dietary nPP (NC; 0.28, 0.24, and 0.21% in the three feeding phases); (3) NC + 600 FTU/kg phytase (PHY); (4) NC + 0.05% multi-strain probiotic (PRO); (5) NC + 0.2% Saccharomyces cerevisiae (SC); and (6) NC + 0.2% fumaric acid. Growth performance data were recorded weekly, and blood sampling was performed at days 21 and 35 of age. Bone quality traits, gut and tibia histology, nutrient digestibility, and intestinal gene expression analyses were conducted at the end of the trial (35 days of age). Final body weight and total gain at day 35 of age of the broiler chickens fed with the PHY, PRO, and SC diets were greater (p < 0.01) than in NC, where broilers fed with the PRO and PHY diets had higher values and were similar to that of PC. There was a non-significant variation in the cumulative feed intake among the treatment groups. The PHY and PRO groups had better FCR than the PC group (p < 0.05), and FA and SC had an FCR equivalent to that of PC. The PHY and PRO broilers had greater dressing % than the NC group (p < 0.05) and even better than PC. The PHY, PRO, SC, and FA broilers had higher relative weights of spleen and bursa of Fabricius (p < 0.01) than NC. In comparison to NC, the PHY, PRO, and SC groups improved (p < 0.05) CP, CF, Ca, and P digestibility. Greater tibia breaking strength of the low nPP-supplemented groups was shown to be associated with higher tibia ash, Ca, and P concentrations (p < 0.01) and increased (p < 0.001) tibia cortical area thickness. At days 21 and 35 of age, the dietary supplements to low nPP diets reduced (p < 0.05) serum total cholesterol, triglyceride, triiodothyronine, thyroxine, glucose, and alkaline phosphatase levels, while serum Ca and P concentrations were improved (p < 0.05) compared to NC. All supplements led to enhancement (p < 0.01) in villi height and width and villi absorptive surface area when compared with NC and were even comparable to that of PC. The mRNA expression of NaP-IIb was up-regulated (p < 0.001) in the duodenum of PRO and FA broilers at day 35 of age compared with NC, and their expression levels were similar to that of PC, indicating greater P availability. It is concluded that dietary supplementation of PHY, PRO, SC, and FA to a low nPP diet was advantageous and mitigated the negative impacts of P reduction on the growth performance, health, nutrient digestibility, and bone quality of broilers.

Performance of an Escherichia coli phytase expressed in Lactococcus lactis on nutrient retention, bone traits and intestinal morphology in broiler chickens

The availability of plant phosphorus in the gut chicken can be improved by increasing phosphorus retention using phytase enzyme or a probiotic with phytase activity as an alternative. In this study, the efficacy of a recombinant probiotic, Lactococcus lactis (L. lactis), with a potential of phytase production was evaluated in broiler chickens. To this aim, 360 one-day-old male broiler Cobb 500 were divided into six treatments with six replicates and reared to 42 days of age. The experimental treatments included positive control diet containing adequate phosphorus (PC), negative control diet containing reduced available phosphorus (NC), negative control diet involving recombinant L. lactis (RLL), negative control diet containing both recombinant L. lactis and Lactobacillus salivarius (RLL + LBS), negative control diet including non-recombinant L. lactis (LL) and negative control diet containing Hostazym^® . Growth performance, total tract apparent disappearance of phytate-P and nutrient retention, mineral content of the tibia and histomorphology of jejunum were evaluated at the age of 35 days. Based on the results, the phosphorus (P) deficiency in the diet reduced body weight (BW), average daily gain (ADG), length and strength of tibia and increased feed conversion ratio (FCR) compared to PC group. However, the supplementation of Hostazym^® or RLL probiotic into the feed improved BW, ADG, FCR, disappearance of Phytate-P and retention of P, length and strength of the tibia in a level similar to PC treatment. Phosphorus content of tibia in the chickens fed P-deficient diets containing RLL was similar to that of the tibia in the control group. Excreta phytate and total P excretion of the chickens decreased when diets contained Hostazym^® , RLL and RLL + LBS. In addition, the diet containing RLL + LBS probiotic increased villi height compared with other treatments (p < .05). Further, recombinant L. lactis could represent phytase activity in the gut environment of the chickens and could be an alternative to the commercial phytase.