The influence of relative humidity during the first 21 days post-hatch on the production performance, biochemical indices, and meat quality of Pekin ducks

This study aims to investigate the effects of different relative humidity (RH) during 4-21d of Beijing ducks on their condition at 42 d. A total of 48 Pekin duck were randomly allotted into 4 treatments (A:RH60 %, B:RH67 %,C:RH74 %,D:RH81 %), each having 3 replicates of 4 ducks. Different humidity treatments were applied from 4 to 21 days. At 42 d, there were no significant differences (P > 0.05) in body weight (BW), average daily gain (ADG), average daily feed intake (ADFI), and feed conversion ratio (FCR) among the 4 groups. Oblique body length in D was significantly higher than that in A (P < 0.05). Compared with A, the chest depth of the other groups was significantly increased, and the abdominal fat weight of B and C was significantly increased (p < 0.05). Liver weight and liver index in C and D significantly higher than that in B (p < 0.05). Abdominal fat ratio in B was significantly higher than that in A (P < 0.05). Cholesterol (CHOL) in D was significantly higher than that in A and C (P < 0.05), triglyceride (TG) in C was significantly higher than that in A and B (P < 0.05), and low-density lipoprotein cholesterol (LDL-C) in B was significantly higher than that in A, C, and D (P < 0.05). pH in B was significantly higher than that in A (P < 0.05), brightness (L*) in A was significantly higher than that in B and C (P < 0.05), redness (a*) in B and C was significantly higher than that in A and D (P < 0.05), and yellowness (b*) in C was significantly lower than that in A and D (P < 0.05).The results indicate that the RH of environment during the brooding period has no impact on duck production performance but induces some oxidative stress damage and changes in meat quality. Additionally, ducks subjected to different RH treatments during the brooding period exhibit varying adaptability to the same environment as they mature.