This study aimed to investigate the effects of different humidity levels on the growth performance, slaughter performance, and meat quality of Pekin ducks through the artificial control of humidity, and to identify the suitable environmental humidity for Pekin duck growth. A completely randomized single-factor design was employed, selecting 144 newly hatched male Pekin ducks with healthy and similar BW (body weight) (60.92 g ± 4.38). These ducks were randomly assigned to four groups (A (RH (relative humidity) = 60%), B (RH = 67%), C (RH = 74%), D (RH = 81%)), with 12 ducks and 3 replicates in each group. The ducks were raised in a climate-controlled room for 42 days with ad libitum access to feed and water. BW and feed intake were measured every 3 days, and slaughter performance and meat quality were assessed at 42 days. There was no significant difference in the ADG (average daily gain) from 1 to 21 days (p > 0.05). The ADFI (average daily feed intake) of Group D was significantly lower than that of Groups A, B, and C (p < 0.05), with no significant differences between Groups A, B, and C (p > 0.05). At 42 days, the BW, ADG, and ADFI of Groups A and C were significantly higher than those of Group D (p < 0.05), with no significant differences among Groups A, B, and C (p > 0.05). Group C had a significantly higher breast muscle weight, breast muscle ratio, liver weight, and liver index than Groups B and D (p < 0.05), with no significant differences between Groups A, B, and D (p > 0.05). The meat shear force in Group C was significantly lower than that in Groups A, B, and D (p < 0.05). The L* (brightness) of Group C was significantly lower than that of Group A (p < 0.05), and the a* (redness) value of Group C was significantly higher than that of Groups A and B (p < 0.05), with no significant difference compared to Group D (p > 0.05). Group B had a significantly higher cooking loss than Groups A, C, and D (p < 0.05), with no significant differences among Groups A, C, and D (p > 0.05). Under 26 °C conditions, Pekin ducks perform best in terms of the production performance and feed efficiency, with high-quality meat, especially when reared at 74% humidity.

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.

This study aims to elucidate the effects of environmental temperature on growth performance, pectoral muscle fiber structure, fatty acid composition, and gene expression in ducks. A total of 72 ducks at 21-day-old were randomly assigned to controlled environments at temperatures of 20°C (T20) and 29°C (T29) from 21 to 42 days of age. Ducks in the T20 group exhibited significantly higher body weight, body weight gain (BWG), average daily gain (ADG), and average daily feed intake (ADFI) at 42-day-old compared to those in the T29 group (P < 0.05). T20 group showed a marked reduction in muscle fiber diameter and area, with an increase in fiber density compared to those raised at T29 group (P < 0.05). The T20 group also had higher levels of various fatty acids, including saturated (SFAs), monounsaturated (MUFAs), and polyunsaturated (PUFAs) types, while T29 group had lower levels of ω-3 and ω-6 PUFAs and a higher ω-6/ω-3 PUFA (P < 0.05). Transcriptomic analysis revealed 544 differentially expressed genes (DEGs) primarily associated with the Cell Cycle, Cell Replication, and PPAR signaling pathways, with key genes cell division cycle 45 (CDC45), chromatin licensing and DNA replication factor 1 (CDT1), and others identified through protein-protein interaction (PPI) network analysis as crucial for temperature regulation of muscle fiber structure and fatty acid composition, particularly within the significantly enriched cell cycle pathway. These findings were validated by qPCR, confirming consistent gene expression trends. The study highlights how ambient temperature affects muscle fiber characteristics and fatty acid composition in ducks, offering insights into potential strategies for optimizing production conditions to enhance meat quality and efficiency.

Pekin ducks are an important meat duck breed, and their growth performance and health status have a direct impact on the production efficiency of the meat industry. This experiment aimed to investigate the effects of post-hatch brooding temperature on the growth performance, meat quality, and serum indicators of Pekin ducks. A total of 144 one-day-old ducks with similar initial body weight were randomly divided into 4 groups: A, B, C and D, with 3 replicates per group and 12 ducks per replicate. The initial temperature in brooding stage was 35°C (1 to 3 d), and then the 4 treatment groups were respectively reduced to temperatures of 20°C, 23°C, 26°C and 29°C (4 to 21 d). Subsequently, the ducks in each group were transferred to a conventional house and continued to feed until 42 d. At 15 d, feed conversion ratio (FCR) in group D was significantly lower than that in other groups. At 18 d, the FCR of group C was significantly lower than that of groups A and B, and that of group D was significantly lower than that of other groups. At 21 d, ADFI in group D was significantly lower than that in group A and group B (P < 0.05). At 42 d, there were no significant differences in BW, ADG, ADFI and FCR among the four treatment groups. Similarly, there was no statistical significance in growth performance, body size, meat quality and antioxidants of ducks (P > 0.05). At 42 d, triglyceride (TG) of the group A was significantly lower than that of the group C (P < 0.05). Under the conditions of this experiment, the later growth of Pekin ducks partially alleviated the effects of different chick-rearing temperatures after hatching.