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1.
This study investigated the putative protective effects of supplemental 2-aminoethane sulfonic acid (taurine) and reduced housing density on renal function in laying hens. We randomly assigned fifteen thousand green-shell laying hens into three groups: a free range group, a low-density caged group, and a high-density caged group. Each group was further divided equally into a control group (C) and a taurine treatment group (T). After 15 d, we analyzed histological changes in kidney cells, inflammatory mediator levels, oxidation and anti-oxidation levels. Experimental data revealed taurine supplementation, and rearing free range or in low-density housing can lessen morphological renal damage, inflammatory mediator levels, and oxidation levels and increase anti-oxidation levels. Our data demonstrate that taurine supplementation and a reduction in housing density can ameliorate renal impairment, increase productivity, enhance health, and promote welfare in laying hens.  相似文献   

2.
The effects of different fatty acid (FA) contents in diet on serum parameters, FA compositions of eggs and meat, and liver morphological changes were studied in Shaoxing laying ducks. A total of 264 ducks at 17 weeks were fed a control diet or a diet containing 30 g/kg fish oil (FO), 25 g/kg sunflower oil (SO), or 30 g/kg palm oil with 20 g/kg beef tallow (PBO). Malondialdehyde (MDA) content in the liver and the serum of ducks fed the PBO diet was significantly (P<0.05) higher than that of ducks fed the other diets. Triglyceride (TG) and total cholesterol (TC) levels were significantly lower (P<0.05) in ducks fed the FO diet. Serum TC also was lower in ducks fed the SO diet. Superoxide dismutase (SOD) activity was also affected by diets. The contents of polyunsaturated FAs (PUFAs) in eggs and meat were significantly higher (P<0.001) in ducks fed the FO and SO diets than in ducks fed the control diet. The level of C22:6 (n-3) FA in ducks fed the FO diet was significantly higher than that in ducks fed the other diets. However, the conversion efficiency of the longer-chain C20:5 (n-3) FA was higher than that of C22:6 (n-3). Ducks fed the PBO diet exhibited lipid droplet accumulation in the liver. These results demonstrate that a diet enriched with different FAs has strong effects on serum lipid levels and the deposition of PUFAs into tissue lipids.  相似文献   

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The goal of this study was to evaluate the effects of a mixture of yeast culture, cell wall hydrolysates, and yeast extracts (collectively “yeast products,” YP) on the performance, intestinal physiology, and health of weaned piglets. A total of 90 piglets weaned at 21 d of age were blocked by body weight, sex, and litter and randomly assigned to one of three treatments for a 14-d feeding experiment, including (1) a basal diet (control), (2) 1.2 g/kg of YP, and (3) 20 mg/kg of colistin sulfate (CSE). No statistically significant differences were observed in average daily feed intake, average daily weight gain, or gain-to-feed ratio among CSE, YP, and control piglets. Increased prevalence of diarrhea was observed among piglets fed the YP diet, whereas diarrhea was less prevalent among those fed CSE. Duodenal and jejunal villus height and duodenal crypt depth were greater in the control group than they were in the YP or CSE groups. Intraepithelial lymphocytes (IEL) in the duodenal and jejunal villi were enhanced by YP, whereas IEL in the ileal villi were reduced in weaned piglets fed YP. Secretion of jejunal and ileal interleukin-10 (IL-10) was higher and intestinal and serum antioxidant indexes were affected by YP and CSE. In YP- and CSE-supplemented animals, serum D-lactate concentration and diamine oxidase (DAO) activity were both increased, and intestinal mRNA expressions of occludin and ZO-1 were reduced as compared to the control animals. In conclusion, YP supplementation in the diets of weaned piglets appears to increase the incidence of diarrhea and has adverse effects on intestinal morphology and barrier function.  相似文献   

4.
为研究早期饲喂对肉鸡生长性能和肠道消化酶的影响,选择360只刚出壳的AA肉用雏鸡,采用单因子试验设计,随机分成4个处理组,每组4个重复,每个重复20只,试验1组出壳后12 h饲喂,试验Ⅱ组出壳24 h后饲喂,试验Ⅲ组出壳36 h后饲喂,对照组出壳48 h后饲喂.饲喂相同日粮,试验期为6周.于21日龄和42日龄分别测定肉鸡进行生产性能和酶活性.结果表明:早期饲喂显著提高了肉鸡的日增重,降低了料重比,试验Ⅰ组和试验Ⅱ组与对照组相比,日增重分别提高了4.19%和3.70%,料重比分别降低5.61%和5.10%,差异显著(P〈0.05);试验Ⅰ组、试验Ⅱ组和试验Ⅲ组肠道消化酶水平高于对照组.早期饲喂提高了肉鸡肠道消化酶水平,以出壳后12 h饲喂最好.  相似文献   

5.
为研究不同营养水平日粮对早期饲喂的肉鸡生产性能和免疫机能的影响,选择刚出壳AA肉仔鸡480只(雌雄各半),对照组饲喂常规日粮,试验Ⅰ组饲喂高营养水平日粮,试验Ⅱ组饲喂低营养水平日粮.结果表明:试验Ⅰ组体重分别比对照组和试验Ⅱ组提高5.28%(P〈0.05)和9.61%(P〈0.05);法氏囊指数分别比对照组和试验Ⅱ组提高6.27%(P〈0.05)和9.75%(P〈0.05),脾脏指数分别提高5.8%(P〈0.05)和13.84%(P〈0.05);试验Ⅰ组新城疫抗体水平分别提高2.92%和12.5%(P〈0.05).高营养水平日粮有利于生产性能和免疫机能的提高.  相似文献   

6.
This study was conducted to investigate the effects of fresh fermented soybean meal (FSM) on the growth performance of nursery piglets, nitrogen excretion in feces, and the concentrations of ammonia (NH3) and particulate matter (PM) in the piggery. A total of 472 nursery piglets (Landrace×Yorkshire, (16.3±0.36) kg body weight) were randomly allocated into two treatments with 236 pigs in each treatment. The pigs were fed the basal diet without fresh FSM (control) or diet containing 10% (100 g/kg) fresh FSM (FSM group), and the crude protein content of the two groups was consistent. The feeding trial lasted for 28 d. The results showed that the pigs fed fresh FSM had increased (P<0.05) average daily gain (ADG) compared with the control. There was no significant difference (P>0.05) in feed to gain ratio (F:G) between the two groups. During the whole experiment, the concentration of NH3 in the piggery decreased (P<0.05) by 19.0%, and the concentrations of PM (PM10 and PM2.5) in the piggery decreased (P<0.05) by 19.9% and 11.6%, respectively, in the FSM group, compared with the control. The ammonia nitrogen and nitrite content in feces increased (P<0.05) by 32.9% and 28.4%, respectively, in the FSM group. The fecal pH declined (P<0.05) significantly in the FSM group compared with the control. At the end of experiment, total protein (TP) concentration was increased (P<0.05) significantly and blood urea nitrogen (BUN) concentration was decreased (P<0.05) for pigs fed the diet with fresh FSM. The results indicated that dietary fresh FSM not only improved the growth performance of nursery piglets, but also reduced the NH3 concentration in the piggery due to nitrogen conversion, and decreased the concentrations of PM10 and PM2.5 in the piggery.  相似文献   

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INTRODUCTION It is well known that antibiotics are used as ef-fective agents to control diseases and as growth promoters in domestic animals. However, the con-tinuous use of antimicrobials increases the bacterial resistance. Therefore, it is essential to find effective and non-resistance replacements. Probiotics are vi-able cell preparations that have beneficial effects on health of the host by improving its intestinal balance (Fuller, 1989) via producing nutrients, enhancingimmune respo…  相似文献   

9.
The effects of dietary supplementation with Clostridium butyricum on growth performance and humoral immune response in Miichthys miiuy were evaluated. One hundred and fifty Miichthys miiuy weighing approximately 200-260 g were divided into five groups and reared in 15 tanks with closed circuiting culture system. The animals were fed 5 diets: basal diet only (control) or supplemented of the basal diet with C. butyricum at doses of 10^3 (CB1), 10^5 (CB2), 10^7 (CB3) or 10^9 (CB4) CFU/g. Compared with the control, the serum phenoloxidase activity was significantly increased by the supplementation (P〈0.05), acid phosphatases activity was increased significantly (P〈0.05) at the doses of 10^9 CFU/g. Serum lysozyme activity peaked at dose of 10^7 CFU/g and in the skin mucus at dose of 10^9 CFU/g. Immunoglobulin M level in the serum and skin mucus was increased except at dose of 10^3 CFU/g (P〈0.05). The growth at the dose of 10^9 CFU/g was higher than that of the control (P〈0.05). It is concluded that supplementation of C. butyricum can mediate the humoral immune responses and improve the growth performance in Miichthys miiuy.  相似文献   

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General Certificates of Secondary Education, known as GCSEs, are organised into modules which can be assessed at the end of the course (linear route) or at different points throughout the course (modular route). This research investigates students’ performance in English and mathematics in each assessment route and the effects of certification session and re-sits on examination outcomes using data from one English awarding body.

In mathematics, modular students performed better than linear students once prior attainment was accounted for. In contrast, modular assessment in English did not always lead to better performance. In the modular routes of English, students certificating early in the course were at a disadvantage compared to those certificating at the end. However, modular mathematics students obtained significantly better results in early sessions than at the end of the course. The benefits of re-sitting seemed clear, as most students performed better on their second attempt at a module than on their first. However, this did not often lead to an improvement on the module grade.  相似文献   


13.
为探索锰元素对甜菜幼苗生长的影响,实验以KWS1176种子为研究材料,采用室内水培法并设置7个浓度梯度:0.0037(T1)、0.0074(T2)、0.0148(T3)、0.0296(T4)、0.0592(T5)、0.1184(T6)、0.2368(T7)mmol·L-1,研究不同锰水平条件下,甜菜幼苗形态特征以及生理...  相似文献   

14.
An implication of the current research on self-regulation is to implement the promotion of self-regulated learning in schools. Teachers can promote self-regulated learning either directly by teaching learning strategies or indirectly by arranging a learning environment that enables students to practise self-regulation. This study investigates teachers’ direct and indirect promotion of self-regulated learning and its relation to the development of students’ performance. Twenty German mathematics teachers with their overall 538 students (grade 9) were videotaped for a three-lesson unit on the Pythagorean Theorem. Students’ mathematics performance was tested several times before and after the observed lessons. A low-inferent coding system was applied to assess the teachers’ implicit or explicit instruction of cognitive strategies (e.g., organisation), metacognitive strategies (e.g., planning), and motivational strategies (e.g., resource management). High-inferent ratings were used to assess features of the learning environment that foster self-regulation. Results reveal that a great amount of strategy teaching takes place in an implicit way, whereas explicit strategy teaching and supportive learning environment are rare. The instruction of organisation strategies and some features of the learning environment (constructivism, transfer) relate positively to students’ performance development. In contrast to implicit strategy instruction, explicit strategy instruction was associated with a gain in performance. These results reveal a discrepancy between the usefulness of explicit strategy instruction and its rare occurrence in classrooms.  相似文献   

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Reading disability (RD) typically consists of deficits in word reading accuracy and/or reading comprehension. While it is well known that word reading accuracy deficits lead to comprehension deficits (general reading disability, GRD), less is understood about neuropsychological profiles of children who exhibit adequate word reading accuracy but nevertheless develop specific reading comprehension deficits (S-RCD). Establishing the underlying neuropsychological processes associated with different RD types is essential for ultimately understanding core neurobiological bases of reading comprehension. To this end, the present study investigated isolated and contextual word fluency, oral language, and executive function on reading comprehension performance in 56 9- to 14-year-old children [21 typically developing (TD), 18 GRD, and 17 S-RCD]. Results indicated that TD and S-RCD participants read isolated words at a faster rate than participants with GRD; however, both RD groups had contextual word fluency and oral language weaknesses. Additionally, S-RCD participants showed prominent weaknesses in executive function. Implications for understanding the neuropsychological bases for reading comprehension are discussed.
Laurie E. CuttingEmail:
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17.
The study assessed the effects of achievement standards, and choice of such standards, on mathematics performance in conditions where no tangible rewards were presented for reaching such standards. Elementary, junior high, and high school students performed a multiplication task in conditions where they chose standards, had standards imposed by an experimenter, or had no standards. Results demonstrated that high school students worked more multiplication problems when they chose standards than when identical standards were imposed by an experimenter or when no standards were present. Moreover, male students who chose standards worked more problems than did male students who had no standards; this effect was not found for female students.  相似文献   

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The purpose of this study was to investigate the effect of cooperative learning and the need for affiliation on performance, time on task, and satisfaction. Subjects used either a cooperative or individual learning strategy while receiving information, examples, practice, and feedback from an instructional television lesson. Results indicated that subjects who worked cooperatively spent more time working on practice exercises and reported greater satisfaction than those who worked individually. In addition, results revealed an interaction between instructional method and the need for affiliation. Performance of subjects with a high need for affiliation who worked alone was lower than that of all other groups when subjects were asked to apply what they had learned from the lesson. Implications for employing cooperative groups in settings that were originally designed for individual learning are provided.  相似文献   

20.
Immediate Knowledge of Results (KR) feedback at the task level may motivate test takers by showing that their answers matter. Appealing feedback cues may help to prevent negative emotions in lower performers who receive a higher amount of negative feedback. In this experiment, we varied the presence of KR feedback and the feedback delivery mode in a 1 × 5 between-subjects design (i.e., no feedback vs. text, color, sound, or animation feedback) to investigate effects on learning outcomes and affective-motivational measures. Our sample included 661 fifth and sixth graders who solved two computer-based multiple-choice science tests. First, students worked on an 18-item treatment test (with experimental feedback manipulation). Students repeatedly rated their effort, enjoyment, pride, and boredom during the test, as well as their expectancy of success and attainment value after the test. Subsequently, they worked on a posttest (without feedback) that assessed recall and near-transfer learning. All KR feedback conditions significantly increased recall, but there was no evidence for near-transfer learning. Feedback had a significant, negative effect on attainment value, whereas significant interactions between the feedback conditions and students’ treatment performance revealed that feedback effects on several affective-motivational dimensions (i.e., expectancy of success, enjoyment, pride, and boredom) were performance-dependent. Feedback benefited higher performers’ motivation and affect but showed negative effects on some affective-motivational measures for lower performers. The pattern of results indicated that color/sound/animation feedback may have reduced the effect of performance on emotional feedback perception to some extent. However, none of the feedback conditions improved affective-motivational outcomes independent of students’ performance.  相似文献   

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