An optimal dietary non-phytate phosphorus level of broilers fed a conventional corn–soybean meal diet from 4 to 6 weeks of age

Abstract

It is imperative to evaluate precise nutrient requirements of animals in order to optimize productivity and minimize feed cost and nutrient excretions. The current non-phytate phosphorus (NPP) recommendation for broilers is based on the papers published 30 years ago. However, today's commercial birds are quite different from those before 30 years. Therefore, the present experiment was conducted with growing male broiler chickens to evaluate an optimal dietary NPP level of broiler chickens fed a conventional corn-soybean meal diet from 4 to 6 weeks of age. The 1-day-old chicks were fed corn-soybean meal diet containing 0.39% NPP from 1 to 3 weeks of age. At 22 days of age, 360 birds were selected and randomly allotted by BW to one of 10 dietary treatments with six replicate cages of six birds per cage for each treatment. Birds were fed the P-unsupplemented corn-soybean meal basal diet and the basal diet supplemented with inorganic P as CaHPO 4 ·H 2 O ranging from 0.00% to 0.45% with 0.05% increment from 4 to 6 weeks of age. The dietary NPP levels were 0.09%, 0.14%, 0.20%, 0.24%, 0.30%, 0.34%, 0.38%, 0.45%, 0.49% and 0.54%, respectively, and the dietary Ca level was fixed at 0.90% for all treatments. The results showed that average daily gain, serum inorganic P concentration, tibia bone strength, tibia ash percentage and P percentage, tibia bone mineral content (BMC) and density (BMD), middle toe ash percentage and P percentage, middle toe BMC, total body BMC and BMD were affected ( P < 0.0001) by dietary NPP level, and increased linearly ( P < 0.0001) and quadratically ( P < 0.003) as dietary NPP levels increased. Optimal dietary NPP levels estimated based on fitted broken-line models ( P < 0.0001) of the above indices are 0.21%, 0.29%, 0.29%, 0.29%, 0.29%, 0.31%, 0.29%, 0.30%, 0.27%, 0.29% and 0.28%, respectively. It is suggested that the total body BMC and BMD, and middle toe ash P and BMC might be new, sensitive and non-invasive criteria to evaluate the dietary NPP requirements of broilers. The optimal dietary NPP level would be 0.31% for broiler chickens fed a conventional corn-soybean meal diet from 4 to 6 weeks of age.

Maternal dietary zinc supplementation enhances the epigenetic-activated antioxidant ability of chick embryos from maternal normal and high temperatures

“…In addition, the aberrant H3K9 hypomethylation accompanied by DNA hypermethylation was observed in the same region of the MT4 gene. Histone deacetylation was associated with gene silencing via alterations in the structure of the nucleosomes or activation of RNA polymerase and other transcription coactivator binding [36, 37]. …”

Dietary calcium or phosphorus deficiency impairs the bone development by regulating related calcium or phosphorus metabolic utilization parameters of broilers

“…The breaking force was determined by the shear test at a speed of 5 mm/min with a 50 kg loading cell until fracture occurred ( Crenshaw et al., 1981 , Shim et al., 2012 , Sadeq et al., 2018 ). The ultimate tibia breaking force was directly obtained from the loaded-deformation curve recorded by a computerized monitor ( Jiang et al., 2016 , Liu et al., 2017 ). The tibia bone was dried using an oven at 105°C for 24 h and then defatted with fresh diethyl ether for 48 h. The fat-free, dried bone was finally ashed using a muffle furnace at 550°C for 16 h. The tibia ash content was expressed on a dried and defatted weight basis of tibia.…”

Phosphorus absorption and gene expression levels of related transporters in the small intestine of broilers

“…All diets were fed in mash form, and the inorganic P in the feed was supplemented with CaHPO 4 .H 2 O. To eliminate the effect of dietary Ca on intestinal P absorption, all diets contained the same amount of Ca (1 %) by adjusting the supplementation of fine sand and limestone ( 17 , 18 ) . Bird weight and feed intake (FI) were measured and corrected for mortality to determine body weight gain (BWG), FI, feed conversion ratio (FCR) and mortality of each cage.…”