Immunoregulatory and antioxidant properties of tryptophan in quail chick.

A dose-response assay was carried out to investigate the effects of graded levels of dietary tryptophan (Trp) on blood variables, immunity, and meat quality in quail chicks during the last two weeks of the growing period. A total of 420 21-day-old quail chicks were randomly distributed across the seven experimental groups (i.e., 2.12, 2.25, 2.38, 2.51, 2.64, 2.77, and 2.90 g Trp/kg of diet) with four pen replicates of 15 birds each. Blood variables, including uric acid (UA), albumin (ALB), and triglycerides (TG), responded inversely to increasing dietary Trp (P < 0.001). The concentration of aspartate aminotransferase (AST) in serum, the relative weight of bursa of Fabricius (BF), immunoglobulin G (IgG), water holding capacity (WHC), and antigen production against the sheep red blood cells (SRBC) increased with increasing dietary Trp (P < 0.001). In contrast, the concentration of malondialdehyde (MDA) and drip loss in meat samples decreased with increasing dietary Trp (P < 0.001). The best models for optimal dietary Trp were identified based on a statistical merit basis known as the model accuracy index (δ). The estimated dietary Trp for optimizing ALP, UA, total protein (TP), TG, SRBC, IgG, BF, drip loss, WHC, and MDA were obtained at 2.347, 2.371, 2,372, 2.485, 2,691, 2.738, 2.306, 2.359, 2.247, and 2.500 g/kg of diet, respectively. Principal component analysis showed that UA, TG, IgG, and drip loss had a higher association with dietary Trp rather than other responses. Considering the high δ and eigenvalues of the models, the best estimation of dietary Trp level required for the optimization of the studied traits in quail chicks would be 2.738 g Trp/kg of diet, which was significantly higher than that recommended for the quail performance by NRC (1994).

A novel methionine nanoparticle in broiler chickens: Bioavailability and requirements.

This bioassay evaluated the bioavailability (RBV) of a novel nanoparticle of methionine (nano-Met) relative to DL-methionine (DL-Met), and estimated methionine requirements for both sources in starting broilers. Five supplemental levels (0.05, 0.10, 0.15, 0.20, and 0.25% of diet) of DL-Met or nano-Met were added to a basal diet containing 0.35% standardized ileal digestible (SID) methionine to create 11 experimental diets, including a basal diet and 10 experimental diets containing 0.40, 0.45, 0.50, 0.55, and 0.60% SID-Met, respectively. A total of 825 one-day-old male Ross 308 birds were randomly assigned to 11 treatments with 5 pen replicates and 15 birds each. Body weight gain (BWG), breast meat yield (BMY), and thigh meat yield (TMY) increased (P < 0.001) while feed conversion ratio (FCR) and malondialdehyde (MDA) concentration in meat samples decreased (P < 0.001) with increasing dietary methionine. Based on the slope-ratio method, the RBV of nano-Met relative to DL-Met for BWG, FCR, and TMY were 102 (48-155%; R2 = 0.71), 134 (68-201%; R2 = 0.77), and 110% (27-193%; R2 = 0.55), respectively. Considering the statistical accuracy of the spline models, the estimated values of DL-Met for maximum BWG and nano-Met for maximum TMY were 0.578% and 0.561%, respectively, which were statistically higher than those recommended for commercial settings. The highest effect size of supplemental methionine was on MDA (ƞ2p = 0.924), followed by FCR (ƞ2p = 0.578), BMY (ƞ2p = 0.575), BWG (ƞ2p = 0.430), and TMY (ƞ2p = 0.332), suggesting the potent antioxidant properties of methionine. Our findings suggest that reducing the particle size of DL-Met to nanoparticles could be a promising strategy to enhance the efficiency of methionine supplementation in broilers, an idea that requires further investigation in future research.

Regression-derived optimal milk thistle in growing quail's diet.

A study was conducted to evaluate the nutritional benefits of milk thistle (Silybum marianum) in quail nutrition as an additive containing antioxidant compounds such as silymarin. A total of 300, 14-d old Japanese quail chicks were randomly allotted to 5 treatments with 6 replicates and 10 birds each. The experimental diets, including a basal diet and 4 diets containing 10, 20, 30, and 40 g/kg milk thistle, were used from d 14 to 35 and spline and segmented models were applied to fit data. The optimized values of dietary milk thistle (breakpoints) for optimum amounts of serum albumin (ALB), total protein (TP), glucose (Glu), magnesium (Mg), calcium (Ca), phosphorus (P), iron (Fe), and water holding capacity (WHC) in meat samples, as predicted by the regression models, were 24.14, 20.00, 20.00, 24.50, 20.00, 10.43, 23.75, and 25.85 g/kg of diet, respectively, based on maximum R2 and minimum Sy.x. While the breakpoints for minimum cooking loss, drip loss, malondialdehyde after 10 and 30 d (MDA10 and MDA30), triglyceride (TG), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), cholesterol (CHOL), uric acid (UA), and creatinine (CRT) were 27.00, 15.82, 15.78, 33.09, 27.39, 17.99, 20.00, 20.00, 20.90, and 32.57 g/kg of diet, respectively. The use of spline models revealed an objective estimate of the optimal amounts of milk thistle for optimizing physiological responses in growing quails. The present analysis showed that higher dietary levels of milk thistle were needed for optimizing meat quality compared to other physiological responses.

Apparent and standardized ileal amino acid digestibilities of corn, wheat, soybean meal, and corn gluten meal in quail chicks.

Two experiments were conducted to measure the apparent and standardized ileal digestibilities (AID and SID) of amino acid (AA) of corn, wheat, soybean meal (SBM), and corn gluten meal (CGM) in growing Japanese quail from 14 to 18 (Exp. 1) and 28 to 32 (Exp. 2) d of age. The basal endogenous losses of amino acids were measured by the use of N-free diet. The birds were fed on standard diet before the use of experimental diets. The experimental diets (four ingredients) and N-free diet were randomly assigned to 5 replicate pens (30 birds per pen) and fed for 5 consecutive days. The ileal digesta were collected on d 18 and 32 for the Exp. 1 and Exp. 2, respectively. AID of lysine (Lys) in corn (P = 0.047), SBM (P < 0.001), and CGM (P < 0.001); AID of threonine (Thr) in corn (P < 0.001), SBM (P < 0.001), and CGM (P = 0.075); and AID of isoleucine (Ile) in wheat (P < 0.001), SBM (P = 0.002), and CGM (P < 0.001) were increased as the birds aged. However, AID of methionine (Met) in corn (P < 0.001) and CGM (P < 0.001), AID of arginine (Arg; P < 0.001) and valine (Val; P < 0.001) in CGM were lower in younger quails. Among indispensable amino acids, the basal endogenous losses of Thr, Val, and Arg decreased by age (P < 0.001). The average of SID of Lys, Ile, Met, Val, Thr, Arg, leucine (Leu), and histidine (His) for corn, wheat, SBM, and CGM were estimated as 83, ND, 89.4, 89.4, 92.1, 90.2, 91.9, and 90.8%; 92.7, ND, 89.1, 93.9, 87.4, 90.2, 89.8, and 88.1%; 90.3, 91.8, 94.3, 90.4, 86.5, 94.0, 84.3, and 95.0%; 82.6, ND, 74.1, 79.6, 84.4, 90.6, 85.2, and 82.4%, respectively. Based on the present study, the AID and SID coefficients of indispensable AA should be adjusted for age classes in Japanese quail during the growing period.

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

A series of experiments was designed and conducted to determine the apparent and standardized ileal phosphorus digestibility (i.e., AIDP and SIDP, respectively) of some grains and protein meals in Japanese quail at different age classes during the growing period from the hatch to 35 d of age. Experimental diets included a PFD, to measure basal endogenous P losses (EPL), corn, wheat, soybean meal (SBM), and corn gluten meal (CGM), so as to be each ingredient the sole source of P, were developed and fed to five experimental groups with 5 replicates of 30 chicks each. Titanium dioxide as an indigestible marker was added to the diets at the rate of 5 g/kg of diet. The EPL in birds fed on PFD was estimated at 201 mg/kg dry matter intake (DMI) and quail chicks fed on PFD exhibited the lowest performance compared to chicks received dietary P regardless of P sources (P = 0.001). The estimated coefficients of AIPD (P = 0.001) | SIDP (P = 0.004) for CGM, corn, SBM, and wheat were 49.2 | 51.9%, 38.8 | 44.9%, 41.4 | 45.9%, and 33.2 | 40.1%, respectively. The mean differences between AIPD and SIPD coefficients with each ingredients including CGM (P = 0.245), corn (P = 0.169), and SBM (P = 0.169) were not statistically significant, while the comparison of those estimations for wheat (P = 0.022) showed significant differences. The present work showed that the use of direct method could successfully estimate the coefficients of P digestibility in growing quail for both the cereals and protein meals that were studied. The high relative contribution of endogenous P in young quail fed on wheat during the first 2 wk posthatch makes it inevitable to correct AIDP for EPL and evoke the implementation of SIDP coefficients in the feed formulation matrix.

The effect of short, long, natural, and intermittent short photoperiods on meat-type Japanese quails.

The present study aimed to investigate the effects of short (8L:16D), long (23L:1D), natural, and intermittent short (8L(15 min L and 45 min D):16D) lighting programs from day 7 of age on the growth performance, carcass attributes, humoral immunity responses, and blood variables of growing Japanese quails through a 4-week production trial. Birds under the long lighting program were found to have 6.88, 6.24, and 5.55% more body weight compared to the natural, short, and intermittent lighting programs, respectively. Feed intake (FI), body weight gain (BWG), and feed conversion ratio (FCR) have increased in those birds exposed to long photoperiod (P < 0.01). The feed conversion ratio in those birds exposed to the intermittent short lighting program improved by 6.92% compared to the long lighting program. The application of long photoperiod increased the relative weight of heart (P = 0.027), and liver and ovaries (P < 0.01), while it decreased the relative weight of breast meat (P = 0.06). Humoral immunity system has boosted in the birds exposed to intermittent short lighting program (P < 0.01). Applying the long photoperiod increased alkaline phosphatase, cholesterol, and triglyceride levels (P < 0.01), while total protein and calcium concentrations were increased using intermittent short lighting program (P < 0.01). The lowest heterophil-to-lymphocyte ratio was observed in the birds raised under the intermittent short lighting program (P < 0.001). The current study revealed that in terms of improving feed conversion ratio, health, and welfare, the intermittent short lighting program (8L (intermittent):16D) could be more appropriate and beneficial for meat-type Japanese quails.

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

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 TiO2 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.