Optimal in‐feed amino acid ratio for broiler breeder hens based on deletion studies

Abstract

An ideal amino acid ratio (IAAR) for breeder hens is needed for maximum nitrogen retention (NR) taking into account nitrogen deposition in body (ND ), feathers (ND ) and egg mass (NEM) to improve dietary protein efficiency. Thus, the aim of this study was to apply the deletion method to derive the IAAR for broiler breeder hens. The nitrogen balance trials were performed from 31 to 35 weeks and from 46 to 50 weeks. Twelve treatments with eight replicates and one hen per cage were used. A balanced diet (BD) was formulated to meet the requirement of all nutrients. The other diets were formulated diluting 55% of BD with corn starch and refilled with amino acids (AAs) and other ingredients, except the AA tested. Each trial lasted 25 days. Feather losses, egg production and egg weight were recorded daily, and the samples were stored to further determine NEM and nitrogen in feather losses (ND ). At the start and the end of each period, a group of birds were slaughtered to further determine ND and ND . The NR was calculated as the sum of ND , ND , ND , NEM and the nitrogen maintenance requirement (NMR). The deletion of valine greatly depressed the NR in peak production (31 to 35 weeks) while the deletion of the isoleucine greatly depressed the NR of the hens from 46 to 50 weeks of age. The percentual reduction in NR and the per cent of the AA to delete from the BD were used to calculate the AA requirement. The average IAAR was Lys 100, Met+Cys 86, Trp 23, Thr 80, Arg 113, Val 90, Ile 91, Leu 133, Phe+Tyr 108, Gly+Ser 94 and His 35. The IAAR was in line with the recommendation from the literature, validating deletion method with the advantages from a rapid and low-cost procedure.

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

“…The egg mass was calculated by multiplying the egg weight by the egg production and then multiplied by the nitrogen content in the egg to calculate the amount of nitrogen deposited in egg mass (NEM). The NEM value is an important part of total N retention that should be considered in further estimation of the genetic potential as well as the utilization efficiency of dietary protein and amino acids for commercial laying hens (Dorigam et al, ).…”

“…It is possible to compare the model parameters bc −1 of an individual AA directly. The ratio between lysine efficiency (reference) and the efficiency of the limiting amino acid under study is utilized to derive IAAR, according to the calculation (Dorigam, ; Dorigam et al, ; Wecke & Liebert, ):…”

“…It is possible to compare the model parameters bc −1 of an individual AA directly. The ratio between lysine efficiency (reference) and the efficiency of the limiting amino acid under study is utilized to derive IAAR, according to the calculation(Dorigam, 2016;Dorigam et al, 2016;):2.6 | Determination of the amino acid requirement and ideal amino acid ratioThe amino acid requirement (g/kg DM) was determined using the following equation proposed byRollin et al (2003):where (EAA) BD is the concentration of the considered EAA in the BD (g/kg DM), DEL is the deletion rate calculated by dividing the EAA concentration in the deficient diet by the EAA concentration in BD, ND EAA is the N deposition (mg N/BW kg0.67 /day) corresponding to the EAA diet, and ND BD is the N deposition observed on the BD (mg N/BW kg 0.67 /day). This method is based on the assumption that N retention is a linear function of dietary essential amino acid content when a particular amino acid is limiting.…”

Functional properties of amino acids: improve health status and sustainability

“…The importance of other amino acids during lay is evident when evaluating nitrogen retention in egg mass. In an amino acid deletion study, hens consuming diets deficient in lysine, tryptophan, valine, and isoleucine had at least 20% lower nitrogen retention in the egg mass compared to those consuming diets formulated to be adequate in all amino acids between 31 and 35 wk of age ( Dorigam et al, 2017 ). The reduction in nitrogen retention indicated that lysine, tryptophan, valine, and isoleucine, may play important roles in egg formation early in lay.…”

Determinação da exigência de lisina e da proteína ideal para suínos na fase de crescimento utilizando o método de Goettingen

“…A exigência de aminoácidos para suínos em crescimento inclui dois componentes, uma exigência para mantença e uma exigência para deposição proteica. Há evidências de estudos demonstrando que o padrão de exigências de aminoácidos para cada espécie é muito diferente (Dorigam et al, 2016), e que a necessidade total do animal deve, portanto, depender da contribuição relativa do aminoácido para mantença e para deposição proteica do total necessário .…”