Pre-cecal phosphorus digestibility for corn, wheat, soybean meal, and corn gluten meal in growing Japanese quails from 28 to 32 d of age

Abstract

The optimization of dietary phosphorus (P) depends on precise details of the P availability in feed ingredients to avoid excess or deficient P in a mixed diet. This study was carried out to measure the apparent ileal digestibility of P for corn, wheat, soybean meal, and corn gluten meal in growing Japanese quails from 28 to 32 d posthatch. A total of 400 quail chicks were randomly distributed across 5 treatments with 4 replicates and 20 birds in each floor pen. The P-free diet (PFD) was formulated based on cornstarch to measure the basal endogenous P losses (EPL). Digestibility coefficients were determined by ileal digesta sampling using TiO 2 as an indigestible marker. The EPL was estimated at 384 mg/kg DMI. The apparent ileal P digestibility (AIPD) for corn, soybean meal, wheat, and corn gluten meal were determined to be 0.38, 0.53, 0.38, and 0.78, respectively. The corresponding values for true ileal P digestibility (TIPD) were 0.48, 0.61, 0.50, and 0.83, respectively. The t -test analysis showed that the difference of AIPD and TIPD values for corn ( P = 0.031) and wheat ( P = 0.015) were statistically significant, however, no significant differences were observed for corn gluten meal ( P = 0.318) and soybean meal ( P = 0.104). In conclusion, the correction of AIPD coefficients for EPL in low-P ingredients such as corn and wheat may be much more important than that in high-P feedstuffs such as corn gluten meal and soybean meal in growing quails.

Research Note: Phosphorus digestibility of corn, wheat, soybean meal, and corn gluten meal in quail chicks

“…As indicated in this experiment, underestimation of AIPD coefficients for tested ingredients could be overcome by correcting for basal EPL that was in agreement with Ghazaghi et al (2019) . In contrast to Ghazaghi et al (2019) , the significant differences among AIPD coefficients in feed ingredients were not disappeared by the correction of AIPD coefficients for EPL. The potential reason for this discrepancy is the lower EPL in the younger birds used in the present study than the older birds used in the study of Ghazaghi et al (2019) .…”

“…More recently, Ghazaghi et al (2019) reported the apparent ileal and true ileal P digestibility values for corn, wheat, SBM, and CGM in growing quail from 28 to 32 d of age. Considering non-phytate P content of feed ingredients as the available P may increase the risk of overfeeding of P because the birds can utilize a portion of phytate-bound P in feed ingredients, and subsequently resulting in increasing P excretion ( Mutucumarana et al, 2014 ).…”

“…Considering non-phytate P content of feed ingredients as the available P may increase the risk of overfeeding of P because the birds can utilize a portion of phytate-bound P in feed ingredients, and subsequently resulting in increasing P excretion ( Mutucumarana et al, 2014 ). The primary concern of this event is the environmental pollution caused by excess excretion of P. Among different methods of the assessment of true P digestibility such as P-free gelatinized diet ( Sulabo and Stein, 2013 ), regression method ( Fan et al, 2001 ) and P-free diet ( Ghazaghi et al, 2019 ), we have used the later method to correct AIPD for basal EPL to determine SIPD. In fact, the former methods may stimulate the endogenous P secretions namely specific endogenous P losses ( Mutucumarana, 2014 ).…”

“…As before stated by Ghazaghi et al (2019) , all feed ingredients were analyzed for gross energy by a bomb calorimeter (Parr 1261 bomb calorimeter, Parr Instruments Co., Moline, IL) using benzoic acid as the standard ( AOAC, 2006 ), dry matter (method 930.15), crude protein (method 968.06), total phosphorus (method 968.08D) according to AOAC (2006) in triplicates. For determination of P and titanium dioxide (TiO 2 ) in feed and digesta samples, each sample was ashed and then P and TiO 2 ( Short et al, 1996 ) were determined colorimetrically (UV mini 1240 Shimadzu Co., Japan) at 680 and 410 nm, respectively.…”

“…The basal EPL, AIPD and SIPD were calculated according to the following equations ( Ghazaghi et al, 2019 ): where EPL was basal endogenous losses of P; AIPD and SIPD were the apparent ileal and standardized ileal P digestibility, respectively; T d and T i were the concentration of TiO 2 in diets and ileal digesta, respectively; P d and P i were the concentration of P in diets and digesta, respectively.…”