The experiment was conducted to investigate the effects of bilberry extract on growth performance, meat quality, antioxidant status, and immune function of yellow-feathered chickens. A total of 360 female hatchling Lingnan chickens were randomly allocated to three treatments with 6 replicates of 20 chickens per replicate. Birds were fed a basal diet supplemented with 0 (the control group), 100 (B100), and 400 (B400) mg/kg of bilberry extract for 63 d. Compared with the controls, (1) dietary supplementation with bilberry extract did not affect the growth performance of chickens from 1 to 63 d. (2) At 21 d, the relative weight of the bursa of Fabricius was increased (p < 0.05) by dietary supplementation with 400 mg/kg bilberry extract. Bilberry extract decreased the concentrations of IgY and IgM in blood plasma of 63-d chickens (p < 0.05). (3) For 21-d chickens, dietary supplementation with 400 mg/kg bilberry extract increased (p < 0.05) the activity of GSH-Px in blood plasma and jejunal mucosa (p < 0.05). Supplementation with 100 mg/kg bilberry extract increased (p < 0.05) the activities of T-SOD in jejunal mucosa and GSH-Px in the liver and decreased (p < 0.05) the MDA concentration in the liver. For chickens at the age of 63 d, both levels of bilberry extract increased activity of T-SOD in blood plasma (p < 0.05) and reduced MDA concentration in the jejunum (p < 0.05). (4) Supplementation with bilberry extract in the diet decreased the MDA concentration (B100) in muscle of 63-d chickens at 45 min postmortem and increased (p < 0.05) the activity of T-SOD (B400) at 4 d postmortem. (5) In breast muscle at 63 d, birds supplemented with bilberry extract (B400) had increased pH and drip loss while drip loss was reduced in the B100 treatment (p < 0.05); treatments did not affect inosinic acid or intramuscular fat contents. In conclusion, dietary supplementation of yellow-feathered chickens with bilberry extract enhanced the relative weight of the bursa of Fabricius, and broadly increased activities of antioxidant enzymes; indices of meat quality were improved without impact on growth performance. Considering the results in the current research, 100 mg/kg bilberry extract was recommended when supplemented in chickens.

An experiment was carried out to investigate the relative bioavailability of tribasic zinc (Zn) sulfate relative to Zn sulfate for broilers fed a conventional corn-soybean meal diet. A total of 504 1-d-old Arbor Acres commercial male chicks were randomly assigned by body weight of birds to one of seven treatments involving a 2×3 factorial arrangement with three levels of added Zn (30, 60, or 90 mg of Zn kg⁻¹) and two Zn sources (tribasic Zn sulfate and Zn sulfate) plus a control with no added Zn for an experimental phase of 14 d. Plasma Zn, tibia ash Zn, pancreas Zn, and pancreas metallothionein (MT) messenger RNA (mRNA) were analyzed at 6 or 14 d of age post-hatching. The results showed that plasma Zn, tibia ash Zn, pancreas Zn, and pancreas MT mRNA increased linearly (P<0.002) as dietary Zn concentration increased at 6 or 14 d of age. The R² for a linear model was greater on d 6 than on d 14 for the above 4 responsive criteria, and among these indices, the fitting of the tibia ash Zn concentration was the best (R²=0.99). Therefore, based on slope ratios from the multiple linear regressions of the above 4 indices of the birds at 6 d of age on daily intake of dietary Zn, the bioavailabilities of tribasic Zn sulfate relative to Zn sulfate (100%) were 95.6% (P=0.18), 83.5% (P=0.01), 87.9% (P=0.53), and 75.9% (P=0.38) for the tibia ash Zn, pancreas Zn, plasma Zn, and pancreas MT mRNA, respectively. The results indicated that generally, Zn from tribasic Zn sulfate was as available as Zn from Zn sulfate for broilers.

The present study was conducted to investigate the effects of synthetic soybean isoflavones (ISO) on the proliferation and related gene expression of sow mammary gland cells. Cells were cultured with 0 (control), 10, 20, or 30 μM of ISO under incubation conditions. After a 48 h incubation, these ISO-incubated cells proliferated more (p < 0.05) than the control cells. Cyclin E expression was higher (p < 0.05) in the 10 μM ISO and 20 μM ISO treatment groups than in the control group. Cyclin D1 and p21 expressions decreased (p < 0.05) with the 10 μM ISO treatment for 48 h. The relative mRNA abundances of the cells’ IG-1R (Insulin-like growth factor-1R), EGFR (Epidermal growth factor receptor), STAT3 (Signal transducer and activator of transcription 3) and AKT (protein kinase B) were enhanced (p < 0.05) by the 20 μM ISO treatment for 24 h and 48 h in the medium. The relative mRNA abundances of κ-casein at 48 h of incubation and β-casein at 24 h and 48 h of incubation were increased (p < 0.05) by 10 μM of ISO supplementation. It was concluded that ISO improved the proliferation of sow mammary gland cells, possibly by regulating cyclins and function genes expression in the cell proliferation signaling pathway.

Recent studies have shown that epigallocatechin-3-gallate (EGCG), as an effective antioxidant, could attenuate the oxidative damage, inflammation and necrosis in the liver in response to oxidative stress. The present study investigated whether oral administration of EGCG could effectively alleviate the hepatic histopathological changes and oxidative damage in yellow-feathered broilers induced by tert-butyl hydroperoxide (t-BHP). Broilers were exposed to 600 μmol t-BHP/kg body weight (BW) to induce oxidative stress by intraperitoneal injection every five days, followed by oral administration of different doses of EGCG (0, 20, 40 and 60 mg/kg BW) and 20 mg vitamin E (VE)/kg BW every day during 5–21 days of age. The results showed that t-BHP injection decreased (p < 0.05) body weight and the relative weight of the spleen; the enzyme activities of total antioxidant capacity (T-AOC), catalase (CAT) and total superoxide dismutase (SOD); and gene mRNA expressions of nuclear factor erythroid 2-related factor 2 (Nrf2), CAT, SOD1, SOD2 and acetyl-CoA carboxylase (ACACA); as well as increased (p < 0.05) necrosis formation, malondialdehyde (MDA) content, reactive oxygen species (ROS)accumulation, and peroxisome proliferator activates receptor-α (PPARα) mRNA expression in the liver of yellow-feathered female broilers at 21 days of age. Treatment with 60 mg EGCG/kg BW orally could enhance antioxidant enzyme activities and reverse the hepatic damage induced by t-BHP injection by reducing the accumulation of ROS and MDA in the liver and activating the Nrf2 and PPARα pathways related to the induction of antioxidant gene expression (p < 0.05). In conclusion, intraperitoneal injection of t-BHP impaired body growth and induced hepatic ROS accumulation, which destroyed the antioxidant system and led to oxidative damage in the liver of yellow-feathered broilers from 5 to 21 days of age. It is suggested that EGCG may play an antioxidant role through the Nrf2 and PPARα signaling pathways to effectively protect against t-BHP-induced hepatic oxidative damage in broilers, and the appropriate dose was 60 mg EGCG/kg BW by oral administration.