Estimation of lysine requirements for growing Japanese quails

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.

Response surface model to illustrate the benefits of tryptophan, melatonin, and N,N-dimethylglycine in quail chicks exposed to aflatoxin B1

A dose-response assay in a central composite design platform was conducted to investigate the responses (performance, immunity, and meat quality) of quail chicks to dietary tryptophan (Trp), melatonin (MEL), and N,N-dimethylglycine (DMG) exposed to aflatoxin B1 (AFB1). A total of 1,275 quail chicks were randomly allotted to 85-floor pens consisting of 17 treatments with 5 replicates and 15 birds per each pen. Dietary MEL and DMG had a different effect on growth rate and interacted with dietary Trp and AFB1 during the first 4 wk of age, while their effect disappeared at the last week of the experiment. Dietary Trp and AFB1 were only significant on the gain of quail chick after d 28 of the assay. During the second and third weeks of age, the reduction in feed intake caused by AFB1 attenuated by dietary MEL and DMG and dietary Trp profoundly affects feed intake in the last 2 wk of the experiment. Dietary MEL and DMG were effective on feed conversion ratio (FCR) during the second and third weeks of age. AFB1 decreased breast meat yield (BMY) and thigh meat yield (TMY), but the inclusion of either MEL or DMG removed the adverse effects of AFB1. Dietary Trp increased BMY, but it did not affect TMY. Increasing dietary Trp linearly increased the Lactobacillus bacteria (LAB) population, and AFB1 negatively impacts the LAB population. The inclusion of dietary DMG removed that negative effect on LAB. Although AFB1 decreased the antibody production against SRBC-antigen, increasing dietary Trp in intoxicated quails increased the plasma antibody in SRBC-challenged birds. At low levels of dietary Trp (0.15-0.19%), the addition of DMG increased malondialdehyde (MDA) production while increasing Trp reversed this adverse situation. In conclusion, these supplements may interact with AFB1 in younger chicks, and dietary Trp and AFB1 have a significant impact on the growth performance of quail chicks during the fifth and sixth week of age.

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.

Efficiency of lysine utilization by growing meat quail

The objective of present study was to estimate the efficiency of lysine utilization by meat quail of 21 to 35 d of age. A total of 500 meat quails were distributed in a completely randomized design in a 2 × 5 factorial arrangement, with 2 sexes (male and female) and 5 digestible lysine levels (0.714, 0.816, 0.918, 1.020, and 1.122%) and 5 replications of 10 birds each. The variables studied were feather-free body weight (FFBW), feed intake (FI), lysine intake (LysI), feather-free body protein deposition (FFBPD), feather-free body lysine deposition (FFBLysD), feather-free body fat deposition (FFBFatD), feather weight (FW), feather protein deposition, feather lysine deposition, and feather fat deposition. The FFBW, FFBPD, FFBLysD, and FFBFatD were regressed as a function of LysI for each sex to estimate the efficiency of lysine utilization in the feather-free body (ELysFFB), and the individual equations were compared. In addition, a multiple regression without intercept was also used to estimate the ELysFFB and in feathers (ELysF) individually. To compare the ELysFFB obtained by the different methods, the t-statistic was used. There was no effect on sex × lysine level interactions for any variable. The females showed higher FFBW (5.07%) and FFBFatD (26.23%) than males. All variables increased with the level of dietary lysine, with the exception of FI, FW, and the deposition of nutrients within them. The ELysFFB values obtained by simple linear regression and multiple linear regression were 48.0 and 44.6%, respectively. As there was no difference in the efficiencies estimated by the different methodologies, the best estimate of ELysFFB was 46.3%, that is, the average. The best estimate of ELysF was 18.1%, obtained by multiple linear regression.