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1.
1. The effect of dietary sorbitol on the performance of broilers was investigated. Male and female broilers were given a control diet or a sorbitol diet (100 g/kg diet) ad libitum from 29 to 57 d of age. 2. Body weight gain, food intake, food efficiency and the ME values of the diets were not significantly different. Absolute and relative weights of abdominal fat were significantly reduced in birds given the sorbitol diet. 3. Compared to the control diet, the diet containing sorbitol lowered the serum glucose, total cholesterol and very low density lipoprotein concentrations.  相似文献   

2.
We evaluated the effects of supplementing betaine on growth performance, fat deposition and lipid metabolism status in broilers kept under chronic heat stress. Five hundred and forty chicks were randomly divided into six groups and the two normal temperature groups were held at normal ambient temperature and fed the basal diet (CONT) and basal diet plus 0.1% betaine, respectively. Heat stressed (HS) broilers were held at 32 ± 1°C from days 22 to 42 and fed the basal diet containing variable levels of betaine. Broilers were examined at days 28, 35 and 42 for body weight, feed consumption, fat deposition and serum lipids. The CONT and betaine‐supplemented groups showed higher (P < 0.01 or P < 0.05) feed consumption, body weight gain, and lower feed : gain ratio compared with the HS‐CONT group. Meanwhile, heat stress increased abdominal, intermuscular and subcutaneous fat deposition, whereas the supplemental betaine significantly decreased those compared with the HS‐CONT group. Additionally, betaine supplementation significantly decreased triglyceride, free fatty acids, low‐density lipoprotein cholesterol and high‐density lipoprotein cholesterol compared with HS‐CONT. Chronic HS reduces broiler production performance. However, betaine can reverse these negative effects partially and thus improve carcass composition by changing lipid metabolism.  相似文献   

3.
1. This experiment investigated the effects of water and Saccharomyces cerevisiae added to wheat-based diets on gastrointestinal, blood and performance parameters of broiler chickens. 2. A total of 160 one-d-old male broiler chicks were given air-dry or wet diets, with or without S. cerevisiae supplementation (0 and 20 g/kg air-dry feed) ad libitum to 42 d. 3. Feeding broilers with a diet mixed with water in a ratio of 1·2 : 1·0 increased body weight, feed intake, abdominal fat, carcase weight, feed transit time and blood HDL (high density lipoprotein) (without yeast). Supplementation with S. cerevisiae increased DM digestibility but reduced ileal pH, ileal coliform population and abdominal fat content. 4. There was a significant interaction between S. cerevisiae and wet feeding, with S. cerevisiae supplementation inducing a significant increase in body weight and feed intake but a reduction of relative abdominal fat and ileal pH of broilers fed on wet diets. 5. It is concluded that wet feeding improved growth performance by increasing feed intake and that the addition of a culture of S. cerevisiae had a growth stimulating effect, as the inclusion of yeast in wet wheat-based broiler diets generated greater responses than yeast in dry-based diets.  相似文献   

4.
1. An experiment was conducted to study the comparative effects of peach palm oil (PPO, Bactris gasipaes H.B.K), crude palm oil (CPO, Elaeis guinenesis), maize oil (MO) and beef tallow (BT) on serum total and lipoprotein cholesterol levels and haemostatic factors in broiler chickens. 2. Four experimental diets were formulated to be isocaloric (14·2 MJ AME(N)/kg) and isonitrogenous (230 g CP/kg). PPO was extracted from the whole dry fruit with hexane. Each fat was added to the diet in an amount equivalent to 25% of total dietary calories. Six replicate groups of eight male broiler chicks were assigned randomly to each dietary treatment. Diets were fed on ad libitum basis. The experiment lasted 42 d. 3. At 42 d, birds were fasted overnight and three chickens/dietary treatment were utilised to draw blood for lipoprotein separation. Various haemostatic factors were determined in thrombocyte-poor plasma. Thrombocyte aggregation was assayed in whole blood. 4. No significant differences were detected in body-weight gain or feed efficiency between the chickens fed on the PPO diet and those receiving the CPO, MO or BT diets. Total serum cholesterol (TC), very low density lipoprotein cholesterol and low density lipoprotein cholesterol (LDL(C)) were not significantly affected after consuming the PPO, CPO and MO diets. Serum high density lipoprotein cholesterol (HDL(C)) was reduced only by the MO diet. Birds fed on the PPO diet had a significantly lower [corrected] LDLC/HDLC ratio compared with other dietary treatments 5. Thrombocyte count and thrombin time were not significantly affected by the experimental diets. Dietary oils significantly affected prothrombin time, fibrinogen concentration and thrombocyte aggregation. PPO and MO diets elicited the lowest fibrinogen levels compared to the CPO and BT diets. Thrombocyte aggregation in broilers fed on the PPO diet was similar to that of the CPO, MO and BT diets. 6. The results suggest that PPO might efficiently provide up to 25% of dietary energy in broiler diets. Additionally, PPO elicited a more favourable LDL(C)/HDL(C) ratio and haemostatic pattern in broiler chickens. These findings may be of general interest to the food industry.  相似文献   

5.
1. An experiment was conducted to study the possibility of replacing soybean meal (SBM) with sunflower seed meal (SFM) in broiler chick diets. The SBM in broiler starter (317.9 g/kg) and finisher (275.4 g/kg) diets was replaced with SFM at 33, 67 and 100% on an iso-caloric and iso-nitrogenous basis using sunflower oil to balance the energy content of the diets. The metabolisable energy levels used in the diet were considerably less than the recommended levels for broilers. Each experimental diet was fed ad libitum from 2 to 42 d of age to 8 replicates of 5 birds. Parameters studied included amino acid and apparent metabolisable energy contents in food ingredients, body weight, food intake, food efficiency, leg abnormality score, dry matter digestibility, carcase traits, relative weight and length of intestine, fat and protein content in liver and serum biochemical profile. 2. SFM had higher concentrations of calcium, phosphorus, methionine and cystine and lower energy content than SBM. 3. Replacement of SBM with SFM up to 67% in starter and 100% in finisher diets did not affect weight gain. Total and 67% replacement of SBM with SFM depressed food efficiency at 21 and 42 d of age, respectively. Food intake was significantly higher in SFM-based diets than in the SBM reference diet at 21 and 42 d of age, except in groups given SFM100 at 21 d of age. In the latter group, the food intake was similar to that on the SBM reference diet. The digestibility of dry matter decreased with increased levels of SFM in the diet. 4. The relative weights of giblet, liver and abdominal fat, length of intestine, activity of alkaline phosphatase, concentrations of calcium and inorganic phosphorus in serum were not influenced by incorporation of SFM in the broiler diet. 5. The ready to cook yield and liver fat content decreased, while the relative weights of gizzard and intestine and protein content in liver increased, with increasing levels of SFM in the diet. 6. The concentration of HDL cholesterol increased while the concentration of LDL cholesterol decreased with increasing content of SFM (> or =67% of SBM) in diet. The serum protein concentration decreased progressively with increase in dietary SFM. The concentrations of protein and triglycerides in serum were lowest in groups receiving SFM100. 7. Body weight gain was not affected by total replacement of SBM with SFM at 42 d of age. However, considering food efficiency, carcase yields, serum lipid profile and level of supplemental fat in diet, it is concluded that SFM can replace up to two-thirds of soybean, corresponding to inclusion of 345 and 296 g SFM per kg for starter and finisher phases, respectively.  相似文献   

6.
ABSTRACT

1. Two separate experiments were conducted to evaluate the efficacy of either prebiotic or synbiotic on growth performance, carcass yield, organ weights, and serum metabolic profile of broilers under hot climatic conditions.

2. In experiment 1, 150 1-d-old Ross 308 male broiler chickens were fed dietary synbiotic (Biomin® IMBO, 0, 1 or 1.5 g kg?1 of the starter diets and 0, 0.5 or 0.75 g kg?1 of the grower diets) for 6 weeks. In experiment 2, 150 1-d-old Ross 308 male broiler chickens were fed dietary prebiotic (Mannan oligosaccharide 0, 0.5 or 1 g kg?1 of the starter diets and 0, 0.25 or 0.5 g kg?1 of the grower diets) for 6 weeks. Each treatment had 10 replicates containing 5 broiler chickens each.

3. Supplementation of synbiotic at 1 or 1.5 g kg?1 feed to broiler diets during 1–21 d and 0.5 or 0.75 g kg?1 feed, respectively, during 22–42 d improved (P < 0.01) body weight gain, feed conversion ratio (FCR), and decreased (P < 0.01) abdominal fat, serum total cholesterol, and low-density lipoprotein (LDL) cholesterol levels in experiment 1.

4. Similarly, supplementation of the prebiotic at 0.5 or 1 g kg?1 in broiler diets during 1–21 d and 0.25 or 0.50 g kg?1 feed, respectively, during 22–42 d improved (P < 0.01) body weight gain, FCR, and decreased (P < 0.01) abdominal fat, serum cholesterol, and LDL-cholesterol levels in experiment 2.  相似文献   

7.
本试验旨在研究饲粮添加万寿菊提取物对肉鸡血清生化指标、抗氧化能力和免疫性能的影响。选取1日龄爱拔益加(AA)肉鸡192只,随机分为3组,每组8个重复,每个重复8只鸡。对照组饲喂基础饲粮,试验组在基础饲粮中分别添加0.15%和0.60%的万寿菊提取物,即有效成分叶黄素含量分别为30和120 mg/kg,试验期42 d。结果表明:与对照组相比,1)饲粮添加0.60%万寿菊提取物使肉鸡血清甘油三酯和低密度脂蛋白胆固醇水平显著降低(P0.05),高密度脂蛋白胆固醇水平显著升高(P0.05);2)0.15%和0.60%万寿菊提取物添加组肉鸡21和42日龄血清总抗氧化能力和超氧化物歧化酶、谷胱甘肽过氧化物酶和过氧化氢酶活性显著提高(P0.05);3)0.60%万寿菊提取物添加组肉鸡21日龄胸腺、脾脏和法氏囊指数显著升高(P0.05),饲粮添加万寿菊提取物使肉鸡血清免疫球蛋白M、免疫球蛋白G和白细胞介素2水平显著升高(P0.05),万寿菊提取物未对肉鸡42日龄免疫器官指数造成显著影响(P0.05)。综上,肉鸡饲粮中添加万寿菊提取物可以提高肉鸡机体的抗氧化能力和免疫性能,且对机体脂代谢有调节作用。  相似文献   

8.
为研究不同剂量的苜蓿素对AA肉仔鸡免疫指标的影响,选取1日龄AA肉仔鸡120只,随机分为4组,对照组饲喂基础日粮,试验Ⅰ~Ⅲ组基础日粮中分别添加150、300、450 mg/kg苜蓿素。分别于28、35和42 d从每组取10只鸡进行采血,测定血清球蛋白含量;取法氏囊和脾脏,称重并计算免疫器官指数;采用MTT比色法测定T、B淋巴细胞增殖能力。结果表明,基础日粮中添加300 mg/kg苜蓿素饲喂28 d,能够显著提高AA肉仔鸡法氏囊指数(P〈0.05);添加450 mg/kg苜蓿素饲喂28 d,能够显著提高AA肉仔鸡血清球蛋白含量和免疫器官指数(P〈0.05)。添加300 mg/kg苜蓿素饲喂35 d,能够显著提高AA肉仔鸡血清球蛋白含量、免疫器官指数(P〈0.05),显著促进B淋巴细胞增殖(P〈0.05);添加450 mg/kg苜蓿素饲喂35 d,能够显著提高血清球蛋白含量、脾脏指数(P〈0.05),显著促进T淋巴细胞增殖(P〈0.05),极显著促进B淋巴细胞增殖(P〈0.01)。添加300和450 mg/kg苜蓿素饲喂42 d,能够极显著提高AA肉仔鸡法氏囊指数(P〈0.01);添加450 mg/kg苜蓿素饲喂42 d,能够显著促进B淋巴细胞增殖(P〈0.05)。结果提示,日粮中添加苜蓿素能够提高多项AA肉仔鸡免疫指标,以添加450 mg/kg效果最优。  相似文献   

9.
This study was conducted to investigate the effects of including potato peels (PP) and sugar beet pulp (SBP), as unconventional feeds, with and without enzyme in broiler diets from 1 to 42 days of age by observing the growth performance, blood parameters and carcass characteristics. A total of 150, 1‐day old, chicks were randomly assigned into five groups, each with 30 chicks. Birds in group 1 were fed on the control diet. Chicks in groups 2 and 3 were offered diets containing PP and SBP at the rate of 15% and 7.5%, respectively, while those in groups 4 and 5 were fed the same diets but with adding an enzyme mixture. Using the unconventional feeds in the diets was found to decrease the body weight (BW). However, the feed intake, weight gain and feed conversion did not differ from the control in PP at the grower period, but decreased in SBP throughout the experiment. Addition of enzyme greatly improved the BW in PP and SBP to a degree that it surpasses the control and also increased the feed intake and conversion. The total cholesterol and low‐density lipoprotein cholesterol serum levels were decreased in all tested groups. Carcass yield was not affected by treatments, but the carcass fat content was reduced using the unconventional feeds with or without enzyme. In conclusion, PP can be used at a rate of 15% in the grower diets of broilers. Furthermore, 15% PP or 7.5% SBP can be included in starter and grower diets, but with the addition of enzymes. This can help in solving the problem of current shortage and rising costs of conventional feeds.  相似文献   

10.
160只1日龄艾维茵肉仔鸡随机分为4组,每组40只,分别饲喂添加0、30、50和100m gk/gL-肉碱的玉米-豆粕型日粮,以研究L-肉碱对肉鸡脂质代谢的影响。经7周试验,结果表明:L-肉碱显著影响了肉鸡血清中甘油三酯、胆固醇、游离脂肪酸、高密度脂蛋白胆固醇的含量和肉鸡腹脂率(P<0.05或0.01),但对肉鸡的生长性能未产生显著影响P(>0.05)。综合各项指标的变化,似100mg k/g L-肉碱对肉鸡的脂肪和胆固醇代谢有较明显的影响。  相似文献   

11.
1. A 56-d experiment was conducted to study the comparative influence of organic and inorganic dietary copper (Cu) sources on growth, blood characteristics and copper accumulation in organs of broilers. 2. A total of 480 Arbor-Acre unsexed broilers were fed on diets containing copper sulphate (CuSO(4)) or copper proteinate (Cu Pro) at concentrations of 50, 100 or 150 mg/kg of Cu supplementation. The birds were given a broiler starter diet from 1-28 d and a broiler finisher diet from 29-56 d which contained 30·8 mg/kg and 41·1 mg/kg basal copper concentration respectively. Growth performance, blood characteristics and Cu accumulation in organs of the broilers were measured. 3. At 28 d, Cu Pro-fed birds had improved feed conversion ratio compared with CuSO(4). At 56 d, birds fed on Cu Pro diets had significantly greater body weight than CuSO(4)-fed birds. Birds fed on CuSO(4) supplemented diets had significantly better feed conversion efficiency. Feed consumptions for the two Cu sources were not significantly different. At no stage did the concentration of added Cu affect the productive traits measured. 4. Cu Pro supplementation increased haemoglobin concentration but reduced plasma triglyceride and plasma cholesterol. Plasma cholesterol decreased as Cu concentration increased. 5. There was a greater accumulation of Cu in the blood, heart, lung, liver and bone of broilers fed on Cu Pro than in those receiving CuSO(4). The liver Cu concentration increased as dietary Cu concentration increased. 6. Cu Pro was more effective in promoting growth and reducing blood cholesterol, and was more bio-available in the organs of broilers.  相似文献   

12.
The objective of this study was to investigate the effects of epigallocatechin gallate (EGCG) on fat metabolism and to establish the molecular mechanism of these effects in broilers. Seventy‐two 28‐day‐old male Ross 308 broiler chickens were divided into three groups with different levels of EGCG supplementation for 4 weeks: normal control (NC) group, L‐EGCG (a low‐level supplement of EGCG, 40 mg/kg body weight daily) and H‐EGCG (a high‐level supplement of EGCG, 80 mg/kg body weight daily). After 4 weeks of oral administration, EGCG significantly reduced the level of abdominal fat deposition in broilers. The serum triglycerides and low‐density lipoprotein cholesterol of chickens in H‐EGCG group were also significantly decreased compared with the NC group, and the high‐density lipoprotein cholesterol was notably increased at the same time. Moreover, the vital role of the liver and abdominal adipose tissue in lipid metabolism of poultry animals was examined through gene expression and enzyme activities related to fat anabolism and catabolism in these organs. Our data show that EGCG supplementation for 2 weeks significantly downregulated the expression of fatty acid synthesis and fat deposition‐related genes, and upregulated the expression of genes involved in fatty acid β‐oxidation and lipolysis genes. Simultaneously, the activities of hepatic fatty acid synthesis enzymes (fatty acid synthase and acetyl CoA carboxylase) were significantly decreased, and the activity of carnitine palmitoyl transferase‐1 was notably elevated. The results suggest that EGCG could alleviate fat deposition in broilers through inhibiting fat anabolism and stimulating lipid catabolism in broilers.  相似文献   

13.
选用健康的1日龄商品代肉用良凤花鸡420只,公母各半,随机分为7组,每组3个重复,每个重复20只,试验鸡自由饮水、采食。试验预试期3 d,从第13天开始,以后每隔10 d逐只称重,并以组为单位计算耗料量。结果显示:添加绿茶粉对肉鸡生长性能没有不良影响,对肉鸡的料重比有降低趋势(P>0.05);可以显著降低肉鸡血清中的甘油三酯(TG)(P<0.05)、胆固醇(TC)(P<0.05)、低密度脂蛋白胆固醇(LDL-C)(P<0.05),显著升高高密度脂蛋白胆固醇(HDL-C)(P<0.05),显著降低肉鸡的腹脂率(P<0.05)、肝脂率(P<0.05),且对第二阶段与脂类代谢相关的血清生化指标的影响比第1阶段更显著。结果表明:在日粮中添加超微绿茶粉可在不影响肉鸡的生长性能的情况下降低体脂蓄积。  相似文献   

14.
1. The objective of this research was to investigate the efficacy of combined or single use of Lactobacillus crispatus LT116 and Lactobacillus johnsonii LT171 on broiler performance. 2. A total of 320 one-d-old male Ross broiler chicks were allocated in 4 experimental treatments for 6 weeks. The experimental treatments received a maize-soybean meal basal diet that was supplemented as follows: 'control', with no other additions; 'LJ', 1 × 10(6) CFU of L. johnsonii LT171; 'LC', 1 × 10(6) CFU of L. crispatus LT116; and 'LCJ', 0·5 × 10(6) CFU of L. johnsonii LT171 + 0·5 × 10(6) CFU of L. crispatus LT116/g of the diet. A suspension of sheep red blood cells (SRBC) was injected into the breast of 8 birds from each treatment on d 14 and 30, and the antibody titre was measured on d 20, 26, 36 and 42. 3. Body weight was improved when compared with control for broilers fed diets supplemented with LCJ. The feed conversion ratio (FCR) decreased in LC and LCJ groups compared with control. The number of coliforms in the ileum of LJ, LC and LCJ birds was lower than that from the control birds. However, only the LCJ treatment significantly decreased the number of coliforms in the caecum. The LCJ group had greater villus height in the duodenum than the LC group, and both LCJ and LC groups showed increased villus height in the duodenum and jejunum relative to the control. Antibody titre against SRBC was higher for the LCJ group than for the LJ and control groups in terms of secondary immune response (mean of 36 and 42 d). 4. This study showed, compared with the control, that the combination of Lactobacillus spp. could positively affect body weight, coliform numbers in the caecum and immune response.  相似文献   

15.
The growth of abdominal fat in chickens from broiler and layer-strains up to 10 weeks of age was measured and compared with changes in plasma very low density lipoprotein (VLDL) concentration and tissue lipoprotein lipase activities. The growth of abdominal fat in broilers was much more rapid than in layer-strain chickens. Plasma VLDL concentrations in the two strains were similar up to 5 weeks of age but thereafter concentrations tended to be higher in broilers. Plasma VLDL concentrations in both strains were much lower than those necessary for maximum lipoprotein lipase activity. The lipoprotein lipase activity of abdominal fat increased much more rapidly in broilers than in layer-strain chickens. In both strains the pattern of its increase relative to body weight was similar to that of abdominal fat. Differences in the lipoprotein lipase activity of abdominal fat between strains were attributed to differences in both activity/adipocyte and number of adipocytes. They were reduced or abolished if activity was expressed relative to tissue weight, or to its content of DNA or protein. The results strongly suggest that the greater lipoprotein lipase activity of the abdominal fat pad in broilers is an important factor in its rapid growth.  相似文献   

16.
探讨血清甲状腺激素水平与鸡脂肪肝出血综合征(FLHs)发生之间的关系。选用14日龄青脚麻鸡160只,按体质量随机分为对照组和FLHS组。对照组饲喂基础日粮,FLHs组饲喂高脂日粮(基础日粮+10%牛油)的同时肌肉注射苯甲酸雌二醇(剂量为2.4mg/kg,每周3次,共3周),试验期为28d。结果显示,试验期间,FLHS组鸡的体温明显降低;28和42日龄时,FLHS组鸡的平均体质量与平均采食量均显著高于对照组(P〈0.05或P〈10.01);皮下脂肪厚度、肌间脂肪宽度、肝指数、肝脂率、皮脂率、腹脂率升高;血清TG、TC和LDL—C浓度均显著高于对照组(P〈0.05或P%0.01),而血清HDL—C浓度均显著低于对照组(P〈0.01);血清T3、T4和FT3水平降低,特别在试验后期降低更明显,而血清FT4水平变化不显著;同时FLHS组血清TP、ALB和PA浓度均比对照组有所提高。结果提示,FLHS可引起血清甲状腺激素水平的下降,而甲状腺激素水平的下降进一步造成脂质代谢紊乱,参与了鸡FLHS的发生。  相似文献   

17.
An experiment was conducted in a completely randomized design to explore the replacement value of toasted guar meal (TGM) for soybean meal (SBM) in commercial broiler diets. Hypothesis was tested by including graded levels (0, 6, 9, 12, 15, and 18% of diet) of TGM to replace maize-SBM on growth performance, apparent nutrient digestibility, carcass traits, and serum parameters. A total of six iso-nitrogenous and iso-caloric diets were prepared, and each diet was fed ad libitum to 12 replicates of five chicks each from 1 to 42 days of age. Results showed that inclusion of TGM up to 12% in broiler diets did not affect the body weight gain, feed efficiency, and energy digestibility. Feed intake, dry matter, nitrogen digestibility, and relative weights of ready-to-cook yields, breast muscle, abdominal fat, liver, and pancreas were not affected (P > 0.05) by incorporating TGM even up to 18% in broiler diets. Concentration of glucose, total protein, and triglyceride in serum was also not affected (P > 0.05), while serum total cholesterol concentration was found to be higher (P < 0.05) in broilers fed diets containing TGM as compared to those fed on 0% TGM diet. From the results, it was evident that TGM may be incorporated up to 12% in commercial broiler diets for better growth performance, nutrient digestibility, and carcass traits.  相似文献   

18.
试验旨在研究丁酸甘油酯对肉鸡生长性能、养分表观消化率、屠宰性能、肠道形态及微生物菌群的影响。选用1日龄罗斯308肉鸡384羽,随机分为4组,每组4个重复,每个重复24羽。对照组饲喂基础日粮,试验组在基础日粮中添加250、500、750 g/t剂量的丁酸甘油酯替代40%的油脂饲喂,试验周期为42 d。结果显示,与空白对照组相比,饲料中添加丁酸甘油酯对于肉鸡的生长性能具有促进作用,其中中剂量组(500 g/t)添加效果最好。各剂量组肉鸡屠宰性能较空白对照组有所改善,但差异不显著(P>0.05);与空白对照组相比,各剂量组十二指肠和空肠肠绒毛高度均有所提高,其中中剂量组与对照组差异显著(P<0.05),各剂量组隐窝深度有变浅的趋势,但差异不显著(P>0.05);与空白对照组相比,中剂量组的粗脂肪和粗纤维表观消化率均显著提高(P<0.05);大肠杆菌数量显著减少(P<0.05),盲肠乳酸菌数量显著增加(P<0.05)。综上所述,基础日粮添加丁酸甘油酯能促进生长性能,提高饲料养分消化率,改善肠道形态和微生物菌群,肉鸡日粮中丁酸甘油酯最佳添加剂量为500 g/t。  相似文献   

19.
A perennial schrub, stevia, and its extracts are used as a natural sweetener and have been shown to possess antimicrobial properties. Stevia contains high levels of sweetening glycosides including stevioside which is thought to possess antimicrobial and antifungal properties. Little is known about the nutritional value of the schrub in livestock. This study determined the potential use of the shrub as a prebiotic animal feed supplement in light of the recent ban on the use of antibiotics in animal feed and the role of its constituent stevioside in the effects of the shrub. Male Cobb broiler chicks were fed a basal broiler diet without antibiotic but with performance enhancing enzyme mix (positive control), a basal diet without antibiotic and enzymes (negative control), or diets in which 2% of the negative control diet was replaced with either dried ground stevia leaves or 130 ppm pure stevioside during 2 week starter and 2 week grower periods. Body weight gains, feed conversion, abdominal fat deposition, plasma hormone and metabolites and caecal short chain fatty acids (SCFA) were measured in the broilers at 2 and 4 weeks of age. There was no significant effect of the treatments on feed intake during the starter period but birds fed diet supplemented with stevia leaves and stevioside consumed more feed (p < 0.05) than those fed the positive control diet during the grower period. Weight gain by birds fed the positive control and stevioside diets was higher (p < 0.05) than those fed other diets only during the starter period. Feed/gain ratio of birds fed the positive control and stevioside diets was superior (p < 0.05) to others. There was no effect of the treatments on nutrient retention and water content of the excreta. Dietary stevia leave and stevioside decreased total concentration of SCFA and changed their profile in the ceca. There was no effect of the treatments on pancreas weight. Dietary stevia reduced blood levels of glucose, triglycerides and triiodothyronine (T3) but had no effect on non-esterified fatty acids. In contrast, stevioside only decreased T3. Both the stevia leaves and stevioside diets significantly increased abdominal fat content. It is concluded that dietary enzyme growth promoters are beneficial to the broilers only during the starter stage and that inclusion of stevia leaves or stevioside has no beneficial effect on the performance of broilers.  相似文献   

20.
为了探究酶解谷朊粉对肉仔鸡免疫功能的影响,本试验选用108只肉鸡,随机分为对照组、谷朊粉组和酶解组3个处理组,每组3个重复。对照组饲喂全价基础日粮,谷朊粉组饲喂添有1.2%谷朊粉的日粮,酶解组饲喂添有1.2%谷朊粉酶解液的日粮。结果表明,日粮中添加谷朊粉酶解物后,在21日龄时,酶解组肉仔鸡的胸腺、法氏囊指数较对照组均有显著提高(P〈0.05),42日龄时,各处理组肉仔鸡的胸腺、法氏囊指数差异均不显著(P〉0.05),而在脾脏指数方面,无论是21日龄还是42日龄,添加酶解谷朊粉组脾脏指数均呈升高趋势(P〉0.05)。对于整个试验期,胸腺、法氏囊的发育有不同程度的促进作用,其中对早期免疫器官的发育具有显著的改善作用。在肉仔鸡整个生长阶段,日粮中添加谷氨酰胺可提高新城疫HI滴度,还可促进肉鸡外周血T淋巴细胞的分裂增殖,其中以42日龄时酶解组提高最为显著。  相似文献   

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