Abstract
ABSTRACT We evaluated the effects of dietary surpluses (100%, 110%, and 120% of Ross recommendations) of methionine (Met) and lysine (Lys) on growth performance, blood serum parameters, immune responses, and carcass traits of broilers using a completely randomized design with a 3 × 3 factorial arrangement. Broilers fed a diet containing Met and Lys according to Ross recommendations had maximal growth performance. During the starter period, higher Lys decreased intake of feed, energy, and protein (linear, P < 0.01) and weight gain (linear, P = 0.01). A diet with 110% Lys decreased feed efficiency (quadratic, P = 0.03) during the grower period and decreased the pre-slaughtered body weight (tendency; quadratic, P = 0.10), and increased serum uric acid (quadratic, P = 0.03). Dietary Lys level had an inverse correlation with serum phosphorus (linear, P = 0.02) and immune response against Newcastle disease virus after the first vaccination (linear, P = 0.03). There were Met × Lys interaction effects on serum glucose (P = 0.01), and relative weights of the rectum (P = 0.02) and liver (P = 0.02). Taken together, our results indicate that dietary surpluses of Met and Lys provided no additional benefits in broiler performance.
Highlights
Methionine (Met) and lysine (Lys) have many important functions in the metabolism of monogastric animals, and consumption of these functional amino acids improves their health, survival, growth, development, and reproduction (Wu 2013; Jankowski et al 2014; Wu et al 2014; Liao et al 2015).The supplementation of corn and soybean diets with Met and Lys, the two major limiting amino acids, is a common practice in poultry production
The aim of the present study was to investigate the effects of dietary surpluses of Met and Lys on growth performance, blood serum parameters, immune responses, and carcass traits of broilers
The results indicate that 110 and 120% Lys levels decreased the Average daily feed intake (ADFI), average daily energy intake (ADEI), and average daily protein intake (ADPI) (Lys, P < 0.01; linear, P < 0.01) and the average daily weight gain (ADG) (Lys, P = 0.03; linear, P = 0.01) during the starter period
Summary
Methionine (Met) and lysine (Lys) have many important functions in the metabolism of monogastric animals, and consumption of these functional amino acids improves their health, survival, growth, development, and reproduction (Wu 2013; Jankowski et al 2014; Wu et al 2014; Liao et al 2015).The supplementation of corn and soybean diets with Met and Lys, the two major limiting amino acids, is a common practice in poultry production. The dietary levels of Met and Lys affect broiler growth, performance, and carcass quality (Corzo et al 2005; Kidd et al 2005; Zhai et al 2016). The addition of high levels of synthetic amino acids, such as Met and Lys, can stimulate insulin secretion (Murray et al 1998), and this increases the uptake of amino acids and protein synthesis in multiple tissues (Sturkie 1986). A high dietary density of amino acids leads to increased breast meat due to an increase of lean muscle tissue, rather than collagen, a structural protein (Corzo et al 2010). Zhai et al (2012) reported that consumption of Met exceeding the dietary requirements increased breast muscle growth via regulation of 6 canonical pathways A high dietary density of amino acids leads to increased breast meat due to an increase of lean muscle tissue, rather than collagen, a structural protein (Corzo et al 2010). Zhai et al (2012) reported that consumption of Met exceeding the dietary requirements increased breast muscle growth via regulation of 6 canonical pathways
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
