Determination of the Optimal In-Feed Amino Acid Ratio for Japanese Quail Breeders Based on Utilization Efficiency

Simple Summary

Breeder reproductive responses are optimized if nutritional, environmental, and health requirements are adequately met. Thus, the ideal concentration of amino acids in the diet must be obtained to prevent excess or deficiency to the animal. This may occur due to the inefficiency in the production or excessive excretion of nitrogen. Therefore, it is necessary to determine the optimal relationship for this nutrient category. These results contribute to ensuring optimal ratios of essential amino acids in the diets of Japanese quail breeders based on amino acid efficiency.

Abstract

The description of the genetic potential is the first step to estimating amino acid requirements and the ideal amino acid relation (IAAR). The aim of this study was to estimate the parameters that describe the daily maximum theoretical nitrogen retention (NR_maxT, mg/BWkg^0.67), daily nitrogen maintenance requirement (NMR, mg/BWkg^0.67), protein quality (b), dietary efficiency of the limiting amino acid (bc⁻¹) and determine the lysine requirement and the IAAR for Japanese quail breeders. Two nitrogen balance assays were performed, one assay using 49 quails distributed in seven treatments (protein levels between 70.1 and 350.3 g/kg) and seven replicates and other assay to determine the IAAR by the use of bc⁻¹, 12 treatments and 10 replicate, with a control diet (CD) and 11 treatments that had limited essential amino acids by providing only 60% of the CD. The values obtained for NR_maxT, NMR, b and bc⁻¹ were 3386.61, 0.000486 and 0.000101, respectively. The daily intake of Lys was 291 mg/bird day. Lys was set at 100% for determining the IAAR: 87, 67, 21, 117, 96, 66, 142, 39, and 133 for Met + Cys, Thr, Trp, Arg, Val, Ile, Leu, His, and Phr + Tyr, respectively, for Japanese quail breeders.

Nitrogen maintenance requirements and potential for nitrogen retention of pullets in growth phase

Experiments were conducted to estimate daily N maintenance requirements (NMRs) and the genetic potential for daily N retention (NR_max T) of pullets in growth phase. Three nitrogen balance trials were conducted, and a total of 48 Hy-line W-36 pullets were used in each trial in age periods (starter: 14-28, grower: 56-70 and developer: 98-112 days). The treatments consisted of six graded levels of nitrogen in the diets (L1 = 8, L2 = 16, L3 = 24, L4 = 32, L5 = 40 and L6 = 48 g N/kg of feed), formulated using the dilution technique. The regression analyses between nitrogen intake and nitrogen excretion were performed to fit the exponential function and to determine the NMR. The daily NMRs that were estimated at 294, 331 and 355 mg/BW_kg ^0.67 for the initial, grower and developer periods, respectively, were applied for further calculation of NR_max T as the threshold value of the function between N intake and daily N balance. The NR_max T was estimated by a statistical procedure following several iteration steps by the Levenberg-Marquardt algorithm until the sum of the squares of the residual was minimized. The NR_max T was estimated at 3,200, 2,633 and 1,826 mg/BW_kg ^0.67 for starter, grower and developer periods respectively. The determined model parameters were the precondition for modelling of the amino acid requirement based on an exponential N-utilization model and depended on performance and dietary amino acid efficiency. This procedure will be further developed and applied in the subsequent study.

Optimal in-feed amino acid ratio for laying hens based on deletion method

A total of 56 Hy‐line W‐36 hens from 28 to 30 weeks were used on nitrogen balance (NB) trial to estimate daily N maintenance requirements (NMR) and the genetic potential for daily N retention (NR_maxT). The treatments consisted of six graded levels of nitrogen in the diets (N1 = 8; N2 = 16; N3 = 24; N4 = 32; N5 = 40; and N6 = 48 g N/kg of feed), formulated using the dilution technique. The regression analyses between nitrogen intake and excretion were performed to fit the exponential function and to determine the NMR = 292 mg/BW_kg^0.67, which was applied for further calculation of NR_maxT = 1,883 mg/BW_kg^0.67. A second NB trial was conducted, and a total of 96 Hy‐line W‐36 hens were used in the same period to estimate the ideal amino acid ratio (IAAR). Twelve treatments with eight replicates and one bird per cage were used. A balanced diet (BD) was formulated to meet the IAAR and the requirement of other nutrients for pullets. The limiting diets were formulated diluting BD with cornstarch and refilled with synthetic AAs and other feed ingredients, except for the AA under study. In each trial, the data of nitrogen intake, excretion, deposition and retention were obtained in a NB trial. The IAAR determined by Goettingen approach was Lys 100, Met+Cys 88, Trp 21, Thr 69, Arg 109, Val 90, Ile 75, Leu 127, Phe+Tir 110, Gly+Ser 73 and His 29%. The IAAR determined by Louvain approach was Lys 100, Met+Cys 88, Trp 21, Thr 69, Arg 104, Val 91, Ile 78, Leu 121, Phe+Tir 119, Gly+Ser 77 and His 29%.

Does the Optimal Dietary Methionine to Cysteine Ratio in Diets for Growing Chickens Respond to High Inclusion Rates of Insect Meal from Hermetia illucens?

The dietary methionine:cysteine (Met:Cys) ratio (MCR) is an important factor influencing the optimal growth of chickens. Therefore, this study aimed to contribute to the assessment of the optimal dietary MCR in diets with the complete replacement of soybean meal (SBM) by a partly defatted larvae meal of Hermetia illucens (HM). A growth study with 240 male meat-type chickens (Ross 308) was conducted, also assessing the body nutrient deposition both at the end of the starter (day 21) and the grower (day 35) period. Birds were fed experimental diets based on wheat, maize, and insect meal (23%/21% HM in starter/grower diets). Sulfur amino acids were created as the limiting AA in diets with graded MCR (40:60; 45:55; 50:50; 55:45; 60:40). The control diet contained SBM instead of HM with a MCR of 50:50. The current results based on growth parameters, dietary protein quality, and Met efficiency data gave support to the previous assumption of an ideal MCR of 50:50, which was also valid in diets with a high proportion of insect meal. The lowest MCR of 40:60 led to significantly impaired feed intake and growth of the birds, while the response to the highest MCR (60:40) was moderate.

N Balance Studies Emphasize the Superior Protein Quality of Pig Diets at High Inclusion Level of Algae Meal (Spirulina platensis) or Insect Meal (Hermetia illucens) when Adequate Amino Acid Supplementation Is Ensured

Two age-dependent nitrogen (N) balance studies (average body mass 25 and 60 kg) utilized 16 male castrated piglets and 16 barrows to measure N utilization parameters of diets with complete substitution of SBM by alternative protein sources (SM, HM), but different AA fortifications. Lysine supplementation up to 80% of the recommended lysine (Lys) supply in diets HM (A) and SM (A) yielded similar protein quality data (63.6 ± 2.1 and 63.7 ± 3.4). Surprisingly, only in piglet diet HM (AA) did the extended AA supplementation (Lys, methionine (Met), threonine (Thr)) enhance protein quality (72.8 ± 6.7) significantly (p = 0.004). Similar trends were observed in growing pigs. However, when the level of histidine (His) in diet SM (AA) was increased, feed protein quality (71.8 ± 1.3) was significantly (p < 0.001) improved indicating the importance of adequate His supply in diets with a complete substitution of SBM by the algae meal (SM) under study. AA efficiency data extend the possibilities to explain the observed responses on protein quality. When an adequate AA balancing in the diet is guaranteed, from nutritional point of view both of the alternative proteins may replace SBM in pig diets.