Black soldier fly (BSF, Hermetia illucens) has been noted as an excellent feed ingredient. However, there is limited information on rearing and processing technology. Thus, this study was conducted to evaluate the substrates for rearing BSF and the optimal processing method for BSF performance. Study separated as 2 experiment, BSF rearing and drying method(Exp 1.) and EP-processing method(exp 2.). During the study, 30 clutches were reared, with 10 per substrate. Three substrates, namely food waste (FW), tofu by-product (TF), and vegetable waste with two drying methods, namely hot air dry (AD) and microwave dry (MW) at expanding (EP) ratios of 5:5 and 7:3, were examined by evaluating their rearing performance, nutrient contents, in vitro digestibility and lipid oxidation stability during storage (0, 14 and 28 days). In experiment 1, the rearing substrates and drying methods were evaluated. Compared with that of conventional methods (FW, AD), the TF substrates and MW method showed higher dry matter contents (3.43%) and in vitro digestibility (1.62%) but lower ether extract contents(3.53%; p<0.05). However, the malondialdehyde (MDA) concentration under MW treatments decreased during storage (5.77%, 4.69% and 3.24%; p<0.05). In experiment 2, compared with that of the 7:3 EP-BSF ratio, the 5:5 EP-BSF ratio showed higher in vitro digestibility (2.70%) and lower MDA concentration during storage (19.19%, 7.96% and 6.42%; p<0.05). In conclusion, the optimal conditions for BSF rearing and ensuring product quality were TF substrates, MW methods and a 5:5 corn:BSF ratio. Therefore, the optimal conditions for producing EP-BSF can present an excellent feed ingredient alternative for swine feed.
Weaning stress is the most common issue in weanling pigs, and increases diarrhea and mortality. Various wavelengths of light irradiation affect the body owing to the association with biophotons. Biophotons are very weak photons in the visible light range generated during metabolic and chemical reactions in vivo. Immune mechanisms are activated by increasing signal transmission between cells through biophoton emission. This study evaluated the influence of ultra-weak light (LED) on growth performance, antioxidant status, and stress of weaned piglets. A total of 120 weaned pigs with an average initial body weight of 7.04±0.01 kg (age: 21 d) were allotted to two treatments (Control and LED) with 10 replicates. Diets prepared in pellet form were administered to the pigs in three phases including Phase 1 (0–14 d), Phase 2 (15–28 d), and Phase 3 (29–42 d). At the end of the study, the average daily gain (8.96%, p<0.05) and feed efficiency (6.56%, p<0.05) of pigs was significantly increased at phase 3 in the LED treatment. Low concentration of malondialdehyde (12.58%, p<0.05) and high concentrations of glutathione reductase (7.41%, p<0.01) and total antioxidant capacity (5.48%, p<0.05) were observed in the LED treatment at Day 42. The concentration of hair cortisol was also decreased (24.05%, p<0.05) in the LED treatment at Day 42. In conclusion, the use of LED for weanling pigs is recommended to improve growth performance by modulating antioxidant capacity and cortisol level in hair.
The physiological functions of the ovary and development of the corpus luteum occur through the activation of endocrine hormones. In this process, estrogen, a reproductive hormone, is secreted in the ovarian follicle and corpus luteum and affects corpus luteum formation and regression. Estrogen controls the synthesis of reproductive hormones by binding to estrogen receptor–α and –β. Estradiol–17β, synthesized in the ovary, regulates the physiological function of the corpus luteum and the angiogenesis signaling pathway. Estrogen controls progesterone synthesis, which is regulated by StAR-transported cholesterol, P450scc-converted pregnenolone in mitochondria, and 3β-HSD-synthesized progesterone in the smooth endoplasmic reticulum. Estrogen secretion is also stimulated by kisspeptin and regulated by gonadotropin-releasing hormone, follicle-stimulating hormone, and luteinizing hormone. Moreover, the formation of the corpus luteum is closely regulated by angiogenesis. VEGF is an important factor in angiogenesis and plays a role in the survival, proliferation, and migration of endothelial cells. Especially, VEGF–A is a key factor in the physiological functions of endothelial cells. VEGF binds VEGFR–2 and affects the signaling pathways of PI3K, Akt, MAPK, and ERK. Also, VEGF binds to HIF–1α, inducing VEGF secretion. Estrogen promotes the activation of HIF–1α, while the activation of mTOR and Akt stimulates VEGF secretion. Therefore, estrogen is a major reproductive hormone in physiological function and the synthesis and secretion of endocrine hormones in the ovary and corpus luteum.