Sericin supplementation preserves sperm functions and fertility during chilled storage of Thai native rooster semen

Effective preservation of rooster semen is important for artificial insemination, but sperm function and fertility decline during chilled storage. This study evaluated whether sericin supplementation could preserve sperm quality, affect malondialdehyde (MDA) generation under an induced oxidative challenge, and maintain fertility in Thai native rooster semen stored at 5°C. In Experiment 1, semen from 30 roosters was diluted 1:3 (v/v) with EK extender containing 0, 1, 2, or 3% (w/v) sericin and evaluated at 0, 24, 48, and 72 h. Sperm motility and kinematics, viability, plasma membrane functional integrity, acrosomal integrity, mitochondrial membrane potential, and MDA equivalents were assessed. In Experiment 2, 40 hens were allocated to four groups based on sericin treatment (0 or 1%) and storage duration (24 or 48 h; 10 hens/group) for fertility and hatchability evaluation. Storage duration reduced sperm quality in all groups ( P < 0.05). However, 1% sericin most consistently preserved sperm quality, particularly after 48 and 72 h ( P < 0.05). Sericin concentration significantly affected MDA equivalents under the induced oxidative challenge (P < 0.05), with sericin-supplemented semen showing lower overall values than the control. In the fertility trial, 1% sericin increased mean fertility from 74.77% to 90.55% after 24 h and from 68.56% to 72.67% after 48 h of storage, corresponding to absolute increases of 15.78 and 4.11 percentage points, respectively (P < 0.05). Hatchability of fertile eggs was unaffected. Overall, 1% sericin provided the most consistent benefit among the evaluated concentrations for chilled preservation of Thai native rooster semen.