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排序方式: 共有21条查询结果,搜索用时 15 毫秒
11.
Litopenaeus vannamei is economically important shrimp species in worldwide aquaculture. This study was conducted to assess the effect of different levels of probiotic Pediococcus pentosaceus (PP) on growth performance, feed utilization, digestive enzyme activity, intestinal microflora count and body composition of L. vannamei. Four diets containing different concentrations [0 (PP0), 106 (PPI), 107 (PPII) and 108 (PPIII) CFU/g] of PP were formulated. After 8 weeks feeding trial, the experimental shrimps were challenged with Vibrio anguillarum and noted the surveillance. At the end of the feeding trial, the obtained results revealed a significant increase (< .05) in final body weight, final length, weight gain (WG), survival rate, protease and amylase activities, lactobacillus sp. and Bacillus sp. intestinal count, total haemocyte counts (THC) and lysozyme activity in PPIII group when compared with the other groups. Similarly, WG, amylase activity, Bacillus sp. count, THC and lysozyme activity were significantly enhanced in case of PPII compared to the control group (< .05). Interestingly, FCR and Vibrio sp. counts were significantly decreased in case of PPIII group when compared to the other groups (< .05). Also, significant level of surveillance was noted in the challenging test with V. anguillarum. These results suggested that the P. pentosaceus improved the growth performance, digestive enzyme activity, immunity and tolerance against V. anguillarum of L. vannamei.  相似文献   
12.
The purpose of this study was to investigate the effects of dietary visceral protein hydrolysate (VPH) of rainbow trout on performance of juvenile Oncorhynchus mykiss. The antioxidant property of VPH was 85% ± 1.6%. Four diets were prepared including VPH free as the control and three diets with 5, 10 and 20 g/kg of VPH inclusions. Juvenile rainbow trouts (n = 252, 9.74 ± 0.22 g) were randomly distributed to experimental tanks. Final results showed the maximum amounts of weight gain and SGR and the lowest FCR value in fish fed with 10 g/kg VPH (p < .05). The highest carcass protein and fat contents were observed in 10 g/kg VPH treatment and the control diet, respectively (p < .05). The largest fat and dry matter digestibility were recorded in fish fed by 5 g/kg VPH (p < .05), while the control and 10 g/kg VPH diets showed the highest levels of protein digestibility (p < .05). Dietary inclusion of VPH improved SOD enzyme activity (p < .05). The results indicate that a diet containing 10 g/kg of VPH inclusion can improve growth performance and some other examined factors in juvenile O. mykiss.  相似文献   
13.
Pregnancy in out-of-breeding season in ewes increases the economical goals. Synchronization of estrus and ovulation is essential for above program. The aims of this study using implant norgestomet with or without Pregnant Mare Serum Gonadotropin (PMSG) were to evaluate the serum progesterone (P4) concentration changes: the conception rate and estimation of the lambing rate and litter size. In total, 80 non-cycling multiparous Iranian Kurdish breed fat-tailed ewes with <0/5 ng/ml P4 were used in April and May 2008 in the suburb of Mashhad, Iran. The animals were randomly divided into three groups: a control group (n = 30) without hormonal treatment, another group (n = 25) received 3 mg of norgestomet implant placed subcutaneously in the convex surface of the ear for 9 days, and the third group (n = 25) treated with 3 mg of norgestomet implant for 9 days with an IM injection of 500 IU PMSG at implant removal. The progesterone of treatment and control groups were measured on days 4, 9, and 13 after removal of the norgestomet using radioimmunoassay. Every five ewes were exposed to one ram after 24 h of norgestomet removal in treatment and control groups, simultaneously. The pregnancy was examined after 25 days of ram removal using ultrasonography. Progesterone concentration was significantly higher in treatment groups on 9 and 13 days after norgestomet removal (P < 0.05). The pregnancy rate in the control, non-PMSG, and PMSG treatments groups were 17%, 52%, and 72%, respectively. The rates of single and twin pregnancy in the non-PMSG treatment group were 69% and 31%, respectively. These rates in norgestomet and PMSG treatment group were 50% and 39%, respectively. Triplet pregnancy (11%) was observed only in the PMSG treatment group. It was concluded that using implant norgestomet especially accompanied with PMSG can increase and improve the fertilization rate of ewe in the out-of-breeding season program.  相似文献   
14.
1. Decreased semen quality is an underlying contributor to age-related subfertility in broiler breeder roosters. This study investigated the effects of dietary curcumin (derived from turmeric) supplementation as an antioxidant source on semen quality and fertility in broiler breeder roosters.

2. Twenty-eight Ross 308 roosters were randomly allotted to four groups with seven birds in each and were fed a standard diet supplemented with different levels of curcumin at 0 (C0), 10 (C10), 20 (C20) and 30 (C30) mg/bird per day from 48 through to 61 weeks of age. Body weight and semen quality traits were evaluated on a weekly basis and seminal concentrations of malondialdehyde (MDA) as a measure of antioxidation status were quantified at one-week intervals during the first 11 weeks of the trial (48–59 weeks of age). Semen samples from last 2 weeks (60 and 61 weeks of age) were used to artificially inseminate to assess the sperm-egg penetration (SP) in perivitelline membrane and fertility rates.

3. Except for body weight and ejaculate volume, other characteristics, including semen concentration, total sperm production, progressive motility and plasma membrane integrity were linearly improved by the increasing levels of curcumin supplementation (P < 0.01). However, dietary curcumin levels were linearly and quadratically associated with decreased seminal concentration of MDA (P < 0.01 and P < 0.03), percentage of abnormal sperm (P < 0.01 and P < 0.07) and increased plasma membrane functionality (P < 0.01 and P < 0.04), respectively. The SP holes in perivitelline membrane were increased in a linear and quadratic manner in response to increasing levels of curcumin (P < 0.01). Moreover, fertility rate was linearly improved (P < 0.01) as the dosage of curcumin increased, and resulted in 8, 12 and 14% improvements in the birds fed C10, C20 and C30, compared to C0, respectively.

4. In conclusion, the results showed that increasing levels of dietary supplementation of curcumin was associated with beneficial effects on semen quality indices and fertility rate in aged broiler breeder roosters.  相似文献   

15.
Bulk milk for the presence of antibodies against bovine viral diarrhea virus (BVDV) from 38 industrial dairy cattle herds complexes with 250-3000 Holstein dairy cows in suburb of Mashhad-Iran was tested. None of the herds were vaccinated against BVDV. Commercial indirect ELISA-kit for the detection of specific antibodies was used. The result could be read visually where the optical density (OD) was measured at 450 nm. The percent positivity (PP) values >or=7 and <7 interpreted positive and negative, respectively. According to this study the apparent and the true prevalence of BVDV antibody-positive herds was 89.47 and 93.98%, respectively. The range of PP was 1.59-107.66 among the herds. The OD in 52.63% bulk milk of the herds was very high. It is concluded that exposure to BVD virus was widely distributed in the dairy cattle herds in suburb of Mashhad-Iran.  相似文献   
16.
17.
This study evaluated the effects of diets containing 0, 25, 50, 75 and 100 g kg?1 Spirulina platensis on proximate composition, fatty acid profile and lipid peroxidation of rainbow trout (Oncorhynchus mykiss). Supplementation of S. platensis did not change moisture and protein contents, but fish fed 50 and 100 g kg?1 S. platensis had lower muscle lipid content than those fed control diet (< 0.05). Fish fed 100 g kg?1 of S. platensis contained lower percentages of saturated and monounsaturated fatty acid and a higher percentage of polyunsaturated fatty acid than those fed control diet (< 0.05). The n‐3/n‐6 ratio of the fatty acid increased and muscle atherogenic and thrombogenic indices were significantly decreased as the dietary supplement of S. platensis increased. Furthermore, lipid peroxidation of the fillet significantly decreased with increasing dietary S. platensis at 4 °C and at ?20 °C (< 0.05). The results of this study show that supplementation of S. platensis to the diet improves muscle quality of the rainbow trout.  相似文献   
18.

Background

Attempts for early detection of gastric cancer have recently focused on host''s genetic susceptibility factors and gene-environment interactions. We have, herein, studied the association of MTHFR C677T single nucleotide polymorphism (SNP) and its interaction with Helicobacter pylori infection, smoking, age and gender on the risk of gastric cancer among an Iranian population.

Methods

Gastric cancer patients (n = 450) and cancer-free controls (n = 780) were studied for serum H. pylori-specific IgG antibodies by ELISA and MTHFR C677T polymorphism (SNP) by PCR-RFLP. Demographic and life style data were collected through patient interviews. Unconditional logistic regression model estimated odds ratio (OR) and the corresponding 95% confidence intervals (CI).

Results

The interactions of MTHFR genotype with H. pylori infection (P = 0.03), age (P = 0.049) and gender (P = 0.007) were statistically significant. Accordingly, MTHFR C677T carriers who were also positive for H. pylori infection exhibited 80% (OR = 1.8, 95% CI = 1.0-2.9) significant excess risk of non-cardia gastric cancer. Furthermore, subjects over the age of 50 or female subjects carrying MTHFR C677T SNP showed 40 (OR = 1.4, 95% CI = 1.0-2.0) and 100 (OR = 2.0, 95% CI = 1.2-3.2) percent increased risk of gastric cancer, respectively.

Conclusion

MTHFR C677T SNP seems to increase the risk of gastric cancer and the effect is significantly inflated by interactions with H. pylori infection, age and gender. Key Words: Helicobacter pylori, Smoking, Gender identity, Age group, Methylenetetrahydrofolate reductase  相似文献   
19.
Various polysaccharides extract from marine algae to increase the non‐specific immune system in crustacean. In this study, effects of hot‐water extract on total haemocyte count, total plasma protein, Phagocytic activity, bacterial clearance efficiency and bactericidal activity while the shrimp Fenneropenaeus indicus (10.12±2.18 g) were immersed in seawater (40 g L?1 and 25±0.8 °C) containing hot‐water extract of brown algae Padina boergesenii at 100, 300 and 500 mg L?1 for 1–4 h, were investigated. These parameters increased significantly (P<0.05) when the shrimp were immersed in seawater containing hot‐water extract at 100 mg L?1 after 3 h and 300 and 500 mg L?1 after 2 h. Fenneropenaeus indicus that were immersed in hot‐water extract at 300 and 500 mg L?1 had significantly increased phagocytic activity and increased clearance efficiency to Vibrio harveyi after 2 h. But bactericidal activity increased after 1 h immersed in 500 mg L?1 concentration.  相似文献   
20.
The application of sewage sludge on farmland is practised in many countries since sludge is rich in macro- and micro- nutrients. However, increasing use of sewage sludge on farmland has raised concerns about the potential transport of heavy metals into food chains and groundwater. This study determined for a calcareous soil the effects of sludge application on soil physical properties and transport of zinc (Zn), copper (Cu), and lead (Pb). Secondary anaerobic digested sewage sludge was applied at rates of 0, 25, 50, and 100 t/ha (on a dried weight basis) for four consecutive years and mixed in the top 20-cm of soil. Corn (Zea mays L.) was planted as a spring crop, followed by wheat (Triticum aestivum) as a winter crop. Sludge application increased the dissolved organic matter content and modified the soil structure, increased the soil infiltration rate, saturated hydraulic conductivity, and aggregate stability, and decreased the bulk density. Sludge application greatly increased DTPA (diethylenetriamine pentaacetic acid)-extractable soil metal concentrations to 50 cm depth and significantly to 1 m. In the plots that received four application of 100 t/ha sewage sludge, the mean concentrations of Zn, Cu, and Pb in subsoil increased by 1600, 7, and 4.5 times, respectively, compared with the control. The results indicate that a combination of enhanced soil physical properties, heavy and inefficient irrigation and high organic matter content with heavy metals cause significant metal mobility. High sludge applications pose risks of groundwater and food chain contamination and rates are best restricted to those reflecting the nutrient demand of crops (20 t/ha every 4 to 5 yr or an average of 4 to 5 t/ha/yr).  相似文献   
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