Effects of yucca extract (YE) on feed efficiency, immune and antioxidative function in

This experiment aimed to investigate the relieving action of Artemisia argyi aqueous extract (AAE) on immune stress in broiler chickens. A 2 × 2 factorial design was used to test the effect of 2 dietary treatments (adding 0 or 1000 mg/kg AAE) and 2 immune stress treatments (injecting saline or lipopolysaccharide (LPS)). A total of 96 one-day-old Arbor Acres (AA) broilers were randomly divided into four treatment groups with six replicates, four birds in each replicate. Broilers in Treatment groups 1 and 2 were fed with the basal diet, and those in Treatment groups 3 and 4 were fed with the experimental diet supplemented with 1000 mg/kg AAE. On days 14, 16, 18 and 20, broilers in both Treatments 1 and 3 were injected intra-abdominally with LPS solution at the dose of 500 μg LPS per kg BW with the LPS dissolved in sterile saline at a concentration of 100 μg/ml, and those in Treatments 2 and 4 were injected intra-abdominally with equal amount of sterile 0.9% saline. Blood samples were collected on days 21 and 28. The results showed that dietary supplementation of AAE prevented reductions in average daily gain (ADG) and average daily feed intake (ADFI) of broilers caused by LPS on d 15-21. On day 21, the injection of LPS increased serum adrenocorticotropic hormone (ACTH) and corticosterone (CORT); meanwhile, feeding AAE reduced the rise of CORT caused by LPS. Immune parameters such as interleukin-1 (IL-1), interleukin-2 (IL-2), interleukin-6 (IL-6), immunoglobulin G (IgG) and immunoglobulin A (IgA) were also improved by LPS, but the content of IL-2 and IgG in broilers fed with AAE diet was significantly lower than that of broilers fed with control diet. All the data suggested that diets supplemented with AAE could relieve the immune stress response of broilers.

This study was conducted to investigate the effect of Artemisia ordosica extract (AOE) on broilers challenged with lipopolysaccharide (LPS). 96 one-day-old Arbour Acres broilers were assigned in 2 Â 2 factorial design, including two dietary treatments (0 or 1000 mg/kg AOE) and two immunological challenge (saline or LPS). on d 14, 16, 18 and 20, broilers were injected intra-abdominally with LPS solution (the LPS was dissolved in sterile saline at a concentration of 100 lg/mL) at 500 lg/kg of base weight, or an equivalent amount of sterile saline. Blood samples were collected on d 21 and 28. During LPS-challenged periods (days 15-21), AOE alleviated the compromised average daily gain and average daily feed intake (p < .05) in broilers challenged with LPS. On day 21, the LPS challenge increased (p < .05) serum adrenocorticotropic hormone, corticosterone, interleukin-1, interleukin-2, interleukin-6, immunoglobulin G and immunoglobulin A, decreased (p < .05) the content of serum growth hormone and insulin-like growth factor-1. However, diet supplemented with AOE reduced the elevation of serum corticosterone (p ¼ .054), interleukin-2 (p < .05), immunoglobulin A (p < .05) and immunoglobulin G (p ¼ .079) caused by LPS on day 21. After a week's recovery, on d 28, AOE reduced the serum interleukin-6 content (p < .05). It may be that AOE exert its beneficial effect on broilers challenged with LPS by lessening the inflammatory cytokines and stress hormone, weakening the over activated immune system and finally, improving the growth performance.ARTICLE HISTORY

Dietary Yucca schidigera extract (YSE) could enhance immune function in broilers, which was attributed primarily to its saponin components. However, YSE also contains phenolic compounds which possess antioxidant ability. This study tested the effects of YSE on growth performance of broilers, its antioxidative enzyme activities and corresponding gene expressions in the small intestine. A total of 128 15‐day‐old broilers were randomly assigned to 4 treatments: corn‐soya bean meal as the basal control diet or the basal diet containing either 100, 200 or 300 mg/kg of YSE. Each treatment consisted of four replicate pens with eight broilers per pen. The experiment lasted 28 days which was divided into a grower period (day: 15–28) and a finisher period (day: 29–42). On day 28 and day 42 body weight (BW), feed intake (FI) and feed conversion rate (FCR) were recorded. Duodenum, jejunum and ileum were collected to analyse superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) activities, malondialdehyde (MDA) concentrations, total antioxidant capacity (T‐AOC) and gene expressions of SOD, CAT, GPx. The results showed that during the grower period a diet including 100 mg/kg YSE improved CAT capacity in the ileum, tended to increase activities of GPx in the duodenum, and further showed enhancing tendencies in SOD and GPx abilities in ileum. Gene expressions of CAT, SOD and GPx in the ileum tended to upregulate at 100 mg/kg YSE level. In the finisher period and over the whole period, all YSE groups had a reduced FI compared to the control group without compromising BW; 100 and 200 mg/kg YSE significantly improved FCR. In conclusion, the improved growth performance of broilers during the finisher period may be due to enhanced antioxidative ability in the grower period with YSE supplementation. This study provided evidence of using YSE as an additive to enhance growth in broilers.

In this study, we tested the effects of Yucca schidigera extract (YSE) on the growth performance in broilers, and furthermore, its effects on antioxidative enzyme activities and corresponding gene in the liver of broilers. A total of 128 14-day-old broiler chickens were randomly assigned to four treatments: maize-soybean meal as the basal control diet and the basal diet containing 100, 200, or 300 mg/kg of YSE, respectively, in this study. Each treatment was consisted of four replicate pens with eight broilers per pen. The experiment lasted 28 days. Average daily gain (ADG), average feed intake (AFI) and feed efficiency (FE) were recorded during grower period (d 15 to d 28) and finisher period (d 29 to d 42), respectively. On day 28 and 42, liver samples were collected to analyse superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) activities, malondialdehyde (MDA) concentrations, total antioxidant capacity (T-AOC), and gene expressions of SOD, CAT, GPx. The results showed that during grower period, there was no difference on growth performance, while CAT activity and its gene expression were increased at 200 mg/kg YSE level. During finisher period, 100 mg/kg YSE supplementation enhanced ADG, and 100 and 200 mg/kg YSE groups improved FE. T-AOC was improved at both 200 and 300 mg/ kg. 300 mg/kg supplementation of YSE enhanced GPx and SOD activity, and decreased MDA concentration. GPx gene expression was up-regulated at 300 mg/kg level. In conclusion, YSE promoted growth performance in broilers as well as exhibited liver antioxidative ability during finisher period.