Effects of dietary lysine levels on carcass performance and biochemical characteristics of Chinese local broilers

Abstract

Lysine is typically the second-limiting amino acid in poultry diets. The objective of this study was to evaluate the effects of dietary lysine concentration on carcass and meat quality traits, and serum parameters in two lines – SD02 and SD03 – which originated from a Chinese local breed, the Erlang Mountainous chicken. Live body weight, carcass traits, meat quality traits (myofibre diameter and density), and serum metabolic markers were measured in high and low dietary lysine groups (HL and LL, respectively) at the end of the starter (1-28 days), grower (29-49 days) and finisher (50-70 days) periods. The results showed that mortality, live weight (LW), myofibre diameter of leg muscle (LFDM) and serum cholesterol (CHO) were greater in HL than LL (P<0.05). The chickens from HL had reduced subcutaneous fat thickness and heart weight than LL (P<0.05). The chickens from line SD02 had greater leg muscle weight, myofibre diameter in breast, and LFDM than line SD03 (P<0.05). The chickens from line SD02 had more serum urea nitrogen and less total proteins than line SD03 (P<0.05). In conclusion, high lysine diets improved slaughter performance and muscle fibre diameter, and SD02 chickens had greater carcass yield and superior meat quality compared with chickens from line SD03.

Keywords

• Erlang Mountainous chicken
• Dietary lysine
• Carcass traits
• Muscle fibre diameter
• Serum parameters