摘要：
The blackness traits, considered an important economic factor in the black-bone chicken industry, still exhibits a common phenomenon of significant difference in blackness of breast muscle. To improve this phenomenon, this study compared growth traits, blackness traits, and transcriptome of breast muscles between the High Blackness Group (H group) and Low Blackness Group (L group) in the Xuefeng black-bone chickens. The results are as follows: 1) There was no significant difference in growth traits between the H group and the L group (P > 0.05). 2) The skin/breast muscle L values in the H group were significantly lower than those in the L group, while the breast muscle melanin content exhibited the opposite trend (P < 0.05). 3) A significant negative correlation was observed between breast muscle melanin content and skin/breast muscle L value (P < 0.05), and skin L value exhibiting a significant positive correlation with breast muscle L value (P < 0.05). 4) The breast muscle transcriptome comparison between the H group and L group revealed 831 and 405 DEGs in female and male chickens, respectively. This included 37 shared DEGs significantly enriched in melanosome, pigment granule, and the melanogenesis pathway. Seven candidate genes (DCT, PMEL, MLANA, TYRP1, OCA2, EDNRB2, and CALML4) may play a crucial role in the melanin production of breast muscle in Xuefeng black-bone chicken. The findings could accelerate the breeding process for achieving desired levels of breast muscle blackness and contribute to the exploration of the mechanisms underlying melanin production in black-bone chickens.
摘要：
The objective of this study was to evaluate the effects of dietary supplementation with different levels of nano-selenium (NS) on growth performance, antioxidant activity, biochemical parameters, and selenium content in Landes geese. A total of 120 80-week-old healthy Landes geese (4.44 +/- 0.03 kg) were randomly assigned to three groups, each with four replicates of 10 birds. The control birds were fed a basal diet without further dietary supplementation (0.0 mg/kg of NS) and the two experimental groups were fed the basal diet supplemented with dietary NS at 0.2 or 0.4 mg/kg of feed. The results demonstrated that NS dietary supplementation had no significant effect on growth performance. Increased total superoxide dismutase activity in serum, breast muscle and liver, glutathione peroxidase level in serum and liver, and catalase in breast muscle and liver were observed for both NS supplemented groups. Additionally, reduced malondialdehyde in serum, breast muscle, and liver was detected in both NS-supplemented groups. Compared with the control, the birds fed diets supplemented with NS had lower concentrations of alanine aminotransferase, triglyceride, aspartate aminotransferase, and low-density lipoprotein cholesterol in serum, while high-density lipoprotein cholesterol was increased. Furthermore, increased selenium, especially in the liver, was found in groups with dietary supplementation of NS. These findings suggest the supplementation of NS in diets can improve antioxidant status, biochemical parameters, and tissue selenium content, although it has no significant effect on growth performance of Landes geese.
摘要：
The abuse of antibiotic growth promoters (AGPs) in feed has led to drug resistance and ecological damage would threaten human health eventually. Natural plants have become a hotspot in the research and application of substituting AGPs because of their advantages of safety, efficiency, and availability. This study was conducted to investigate the effects of Macleaya cordata extract (MCE) in the diet of Xuefeng black-bone chicken on laying performance, egg quality, and serum indices. In this study, 576 birds (47-week-old) were evenly distributed between 4 treatments with 6 replicates of 24 hens each. The control group was fed a basal diet without MCE and the remaining groups received 100, 150, or 200 mg/kg MCE for 84 d. Results revealed that the strength and thickness of the eggshell increased significantly with the dietary addition of MCE (P < 0.05). The serum concentrations of glutathione peroxidase increased in the MCE groups (P < 0.01). Simultaneously, progesterone, follicle stimulating hormone, estradiol as well as serum luteinizing hormone levels also increased with the addition of MCE (P < 0.05). Compared with the control group, supplementation of MCE significantly decreased the tumor necrosis factor-alpha and interleukin-6 levels (P < 0.01). In summary, it was concluded that diet addition of 200 mg/kg MCE ameliorated egg quality, enhanced antioxidation and immune activity, and regulated hormone secretion of Xuefeng black-bone chicken.
关键词：
Bacillus subtilis;intestinal barrier;laying hen;montmorillonite;oxidation status
摘要：
This study was conducted to evaluate the effects and combinational effects of Bacillus subtilis (BS) and montmorillonite (MMT) on laying performance, gut mucosal oxidation status, and intestinal immunological and physical barrier functions of laying hens. Three hundred sixty laying hens (29-week-old) were randomly assigned to a 2 x 2 factorial arrangement of treatments (n = 6) for 10 wk as follows: (1) basal diet; (2) the basal diet plus 5 x 10(8) cfu BS/kg; (3) the basal diet plus 0.5 g MMT/kg; and (4) the basal diet plus 5 x 10(8) cfu BS/kg and 0.5 g MMT/kg. Dietary supplementation with BS increased egg production and egg mass, the activities of catalase (CAT) and total superoxide dismutase in the intestinal mucosa, and villus height and villus height-to-crypt depth ratio of the jejunum (P < 0.05) but downregulated the mRNA expression levels of toll-like receptor 4 and myeloid differentiation factor 88 (MyD88) in the duodenum and jejunum, interleukin 1 beta in the duodenum, and nuclear factor kappa B P65 (NF-kappaB P65) and tumor necrosis factor alpha in the jejunum (P < 0.05). Dietary supplementation with MMT increased egg production and egg mass, the concentration of secretory immunoglobulin A in the duodenum, and the occludin mRNA expression level in the jejunum (P < 0.05) but reduced feed conversion ratio, malondialdehyde concentration in the duodenum and jejunum, and the mRNA expression level of MyD88 in the jejunum (P < 0.05). In addition, there was an interaction effect between BS and MMT supplementation on the CAT activity and the MyD88 mRNA expression level in the duodenum and the mRNA expression level of occludin in the jejunum (P < 0.05). In conclusion, dietary BS and MMT and their combination may improve the intestinal health status of laying hens, which may contribute to the increase in hens' laying performance.
