Effects of dietary surpluses of methionine and lysine on growth performance, blood serum parameters, immune responses, and carcass traits of broilers

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.

KEYWORDS:

• Amino acids
• anatomical parts
• antibody response
• carcass yield
• feed efficiency
• poultry

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Samantha Sigolo http://orcid.org/0000-0001-9081-0565

Alireza Seidavi http://orcid.org/0000-0002-1903-2753

Antonio Gallo http://orcid.org/0000-0002-4700-4450

Aldo Prandini http://orcid.org/0000-0002-8650-8766

Additional information

Funding

This work was supported by the Rasht Branch, Islamic Azad University [grant number 17.16.4.8774].