共查询到20条相似文献，搜索用时 31 毫秒
1.
Carry-over effects of dietary yeast RNA as a source of nucleotides on lymphoid organs and immune responses in Leghorn-type chickens 总被引：1，自引：0，他引：1
1. The carry-over effects of supplementing Leghorn-type chickens with yeast RNA as a dietary source of nucleotides for 4 weeks on growth, lymphoid organ weights and immune responses were assessed in a 12-week study. 2. A commercial starter feed supplemented with 0 (control), 5 (LR) or 10 (HR) g yeast RNA/kg was offered to 1-d-old male ISA Brown chicks for 4 weeks, and then all birds were given a commercial pullet grower feed for another 8 weeks. Growth performance, antibody responses to sheep red blood cells (SRBC) and cutaneous reactivity of toe webs to phytohaemagglutinin (PHA)-M were measured at 4-week intervals. 3. Growth rates, feed intake and feed efficiency were not affected by dietary yeast RNA during the supplementary period, but birds previously offered the HR diet grew faster than control birds during weeks 4 to 8.4. LR-fed birds had a higher spleen weight relative to body weight (BW) than control birds at week 4, but this effect was not detected at other times. 5. Serum primary antibody levels against SRBC were not affected by dietary yeast RNA at any time. 6. The toe-web PHA response was significantly higher at week 8 in control birds than in birds previously given the LR diet, although no difference among dietary treatments was observed at other times. 7. It is concluded that the addition of yeast RNA as a source of nucleotides to a commercial diet selectively stimulated the development of the spleen in young birds, but this effect did not persist into a later stage of the bird's life. 相似文献
2.
The effects of a short-term dietary arginine supplementation after hatching on subsequent growth and the immune system were assessed in growing male Leghorn-type chickens. An arginine-deficient basal diet (67 g/kg) supplemented with 0 (control), 2.7 (LA) or 5.4 (HA) g L-arginine/kg, was offered ad libitum to 1-d-old male ISA Brown chicks for 4 weeks, then all birds were offered ad libitum a commercial pullet grower feed (8.9 g arginine/kg) for another 8 weeks. Supplemented birds had higher growth rates and feed intake than control birds during the 4-week supplementation period, but these effects did not persist into the subsequent periods. When the supplementation ceased at week 4, no differences in lymphoid organ weights relative to body weight (BW), primary serum antibody levels against sheep red blood cells (SRBC) or cutaneous reactivity of toe webs to phytohaemagglutinin (PHA) were detected. LA-fed birds had lower immunoglobulin (Ig) G levels against bovine serum albumin (BSA) than the control at week 4, but this effect did not persist at weeks 8 and 12. No difference in anti-BSA IgM levels was detected among birds at week 4; at week 12, however, the LA-fed birds had a significantly higher anti-BSA IgM level than the control. An increased anti-SRBC antibody level and a reduced relative bursa weight in HA-fed birds were evident at week 8, without any prior effects. It is concluded that short-term supplementary L-arginine had minimal effects on immunity, but some enhancement of SRBC antibody responses in later stages of growth was observed with previous L-arginine administration. 相似文献
3.
J J Giambrone D L Ewert R D Wyatt C S Eidson 《American journal of veterinary research》1978,39(2):305-308
Chickens fed 2.5 microgram of aflatoxin/g of diet from 2 to 4 weeks of age or from hatching to 4 weeks were deficient in cell-mediated immunity, as measured at 4 weeks of age by the graft-versus-host reaction. Delayed-type hypersensitive skin reactions to tuberculin were also reduced in chickens given dietary aflatoxin from hatching to 7 weeks of age. Humoral immunity, as measured by the ability of 4-week-old chicks to produce natural agglutinins to rabbit red blood cells, was not significantly altered by dietary aflatoxin. A significant decrease in concentrations of serum immunoglobulins (Ig) IgG and IgA, but no IgM, however, did occur in chicks given dietary aflatoxin from hatching to 4 weeks or between 2 and 4 weeks of age. Aflatoxin consumption from 0 to 2 weeks of age produced no marked effect on either cell-mediated or humoral immunity in 4-week-old chicks. 相似文献
4.
A live attenuated Salmonella enterica serovar Montevideo (SM) mutant JOL1599 was constructed by deletion of virulence-associated genes. The protective efficacy and immune response profiles of chickens immunized with JOL1599 were investigated. Immunized chickens demonstrated significant increases in plasma IgG and lymphocyte proliferative responses (P ≤ 0.05). Increased levels of IL-6, INF-γ, and IL-12 were also observed. Immunized birds strongly responded to infection by rapid stimulation of a CD4+ subset of T cells. Organ bacterial recovery assay revealed a significant reduction in the challenge strain among immunized birds. Multiple doses of JOL1599 enhanced the immune responses of the birds as revealed by ascending trends of the immunological profiles. These findings indicate that immunization of chickens with JOL1599 may provide protection against Salmonella Montevideo infection via induction of IL-6, INF-γ, and IL-12 protective cytokines, which in turn triggers conducive humoral and cell-mediated immune responses. 相似文献
5.
Placha I Borutova R Gresakova L Petrovic V Faix S Leng L 《Journal of animal physiology and animal nutrition》2009,93(6):695-702
This study examined the effects of excessive dietary supplementation with organic selenium on phagocytic activity and antioxidative status of chickens for fattening fed diet contaminated with deoxynivalenol (DON). Sixty chickens of Ross 308 hybrids were at day of hatching divided into four groups with 15 birds in each. The background DON dietary levels in both negative and positive control groups were 0.2 mg/kg. The complete feed for positive control group was supplemented with Se dose 1 mg/kg in the form of Se-yeast. Group 3 was fed diet with DON level 3 mg/kg while diet for group 4 combined DON level 3 mg/kg with a excessive supplement of Se-yeast (Se dose 1 mg/kg). After 6 weeks of dietary intake, six randomly-chosen chickens from each group were sampled. Feeding of contaminated diet resulted in significantly reduced blood phagocytic activity (19.5 ± 1.1% in the negative control vs. 12.8 ± 0.8% in the DON-treated group, p < 0.05). Se-yeast supplemented to the DON contaminated diet prevented suppression of phagocytic activity. Dietary intake of DON at levels 3 mg/kg did not influence the plasma α-tocopherol level while excessive dietary Se dose reduced it in both Se supplemented groups. Neither the birds of DON-treated group nor the birds from group 4 with DON and Se-yeast showed any response in plasma γ-glutamyltransferase (GGT) activity. Subtoxic dietary level of DON significantly increased the activity of glutathione peroxidase (GPx) in the duodenal mucosa, while additional Se supplementation prevented such a response to mycotoxin. On the other hand, both Se supplemented groups showed significantly elevated GPx activities in blood, liver and kidney, (p < 0.05). The results suggest a potential ability of excessive supplementation of organic selenium to prevent the blood phagocytic activity suppression and changes in GPx activity in duodenal tissue induced in broilers by subtoxic dietary levels of DON. 相似文献
6.
O. E. Oke 《Tropical animal health and production》2018,50(5):1071-1077
Dietary manipulation has been seen as one of the practical ways to ameliorate the adverse effects of thermal stress in the hot humid tropical climate. In order to investigate the influence of Curcuma longa (turmeric) rhizome powder on physiological responses and performance under hot humid tropical climate, 240 broiler chicks were randomly assigned to four dietary treatments having four replicates of 15 birds each in a complete randomized design. Broiler birds were fed basal diets and supplemented with 0 (CT), 4 (TG), 8 (FT), and 12 g (SG) of turmeric powder/kg of diet for 8 weeks. Data were collected weekly on feed intake and body weights. Blood samples were collected from eight birds per treatment at week 4 (starter phase) and week 8 (finisher phase) of the experiment for the determination of plasma 3,5,3′-triiodothyronine (T3), superoxide dismutase (SOD), malondialdehyde (MDA). Rectal temperature of the birds was also taken. At 56 days of age, eight birds from each treatment were slaughtered for the determination of relative organ weights. Results showed that the final weights of the birds in FT were significantly higher than those of the birds in TG, SG, and CT. The weight gain of the birds in FT was higher than those of the birds in SG while those of SG were higher than those of TG whose values were higher than that of CT. The feed conversion ratio of the broiler chickens in CT was higher (P?<?0.05) than those of other treatment groups while the birds in FT and SG had similar feed conversion ratios. SOD of birds fed turmeric rhizome powder was higher than the birds in the control group at both starter and finisher phases. Furthermore, MDA of the birds in FT was lower than those of the birds in the other treatment groups at the finisher phase. Plasma T3 was higher in the birds fed turmeric at the finisher phase than chickens in the control group. There was no difference in the rectal temperatures of the birds. To conclude, turmeric rhizome powder improved the physiological response and performance of broiler chicken under hot humid tropical climate in a dose-dependent characteristic and the optimum supplementation rate of 8 g/kg of diet was recorded. 相似文献
7.
Dietary lutein stimulates immune response in the canine 总被引：7，自引：0，他引：7
Kim HW Chew BP Wong TS Park JS Weng BB Byrne KM Hayek MG Reinhart GA 《Veterinary immunology and immunopathology》2000,74(3-4):315-327
The possible immuno-modulatory action of dietary lutein in dogs is not known. Female Beagle dogs (17-18-month old; 11.4+/-0.4kg body weight) were supplemented daily with 0, 5, 10 or 20mg lutein for 12 weeks. Delayed-type hypersensitivity (DTH) response to saline, phytohemagglutinin (PHA) and a polyvalent vaccine was assessed on Weeks 0, 6 and 12. Blood was sampled on Weeks 0, 2, 4, 8 and 12 to assess (1) lymphocyte proliferative response to PHA, concanavalin A (Con A), and pokeweed mitogen (PWM), (2) changes in peripheral blood mononuclear cell (PBMC) populations, (3) interleukin-2 (IL-2) production and (4) IgG and IgM production. After the completion of 12-week study, we continued to collect the blood weekly up to 17 weeks to evaluate the changes in immunoglobulin production upon first and second antigenic challenges on Weeks 13 and 15. Plasma lutein+zeaxanthin was undetectable in unsupplemented dogs but concentrations increased (P<0.05) rapidly on Week 2 in lutein-supplemented dogs. Thereafter, concentrations generally continued to increase in dose-dependent manner, albeit at a much slower rate. Dogs fed lutein had heightened DTH response to PHA and vaccine by Week 6. Dietary lutein increased (P<0.05) lymphocyte proliferative response to all three mitogens and increased the percentages of cells expressing CD5, CD4, CD8 and major histocompatibility complex class II (MHC II) molecules. The production of IgG increased (P<0.05) in lutein-fed dogs after the second antigenic challenge. Lutein did not influence the expression of CD21 lymphocyte marker, plasma IgM or IL-2 production. Therefore, dietary lutein stimulated both cell-mediated and humoral immune responses in the domestic canine. 相似文献
8.
本试验旨在研究饲粮添加乳化剂与L-肉碱对肉鸡生长性能和血脂指标的影响。试验采用2×2因子完全随机设计,选用960只1日龄科宝白羽肉公鸡,随机分为4个处理,每个处理6个重复,每个重复40只鸡。试验分为前期(1～21日龄)、后期(22～49日龄)和全期(1～49日龄)。结果表明:1)与对照组相比,添加乳化剂极显著或显著降低了1～21和1～49日龄料重比(P<0.01,P<0.05),提高了21、49日龄血清游离脂肪酸含量(P<0.01);添加L-肉碱或乳化剂与L-肉碱合用均极显著或显著降低了各期料重比(P<0.01,P<0.05),显著降低了21日龄血清甘油三酯和极低密度脂蛋白含量(P<0.05);添加L-肉碱极显著提高了49日龄血清游离脂肪酸含量(P<0.01)。2)主效应分析表明,添加乳化剂显著提高了21日龄血清总胆汁酸、游离脂肪酸含量(P<0.05);添加L-肉碱极显著降低了各期料重比(P<0.01),提高了胸肌率(P<0.01),降低了21、49日龄血清甘油三酯、极低密度脂蛋白含量(P<0.01,P<0.05),降低了21日龄血清总胆固醇和游离脂肪酸含量(P<0.05);乳化剂与L-肉碱的交互作用显著或极显著影响1～21和1～49日龄料重比、21和49日龄血清游离脂肪酸含量(P<0.01,P<0.05)。结果提示,饲粮单独添加乳化剂、L-肉碱或二者合用均可改善肉鸡的饲料利用率,提高胸肌率,降低血清甘油三酯、极低密度脂蛋白含量。单独添加乳化剂或L-肉碱均可提高血清游离脂肪酸含量,二者合用较单独添加降低了血清游离脂肪酸含量。高温(30～35℃)饲养环境下,建议在肉鸡饲粮中单独添加乳化剂或L-肉碱。 相似文献
9.
Schonewille E Singh A Göbel TW Gerner W Saalmüller A Hess M 《Veterinary immunology and immunopathology》2008,121(1-2):130-139
In the present investigation flow cytometric analysis and immunohistochemistry were applied together for the first time to gain new insights into the interaction between virulent fowl adenoviruses (FAdV) and the immune system of chickens. As a model for virulent FAdV infections a FAdV-4 strain was used, known as the aetiological agent of Hepatitis-Hydropericardium syndrome (HHS) in broilers sometimes also named Angara Disease. Specified pathogen-free chickens (SPF) were divided into three different groups. Group I was infected at first day of life with an attenuated form of the virus obtained through continuous cell culture passage with the virulent virus and then re-infected 3 weeks later with the virulent progenitor virus. Group II was solely infected with the virulent virus at 3 weeks and group III served as a negative control. Following infection with the virulent virus a decrease of CD3+, CD4+ and CD8+ cells was noticed in the spleen. This was accompanied by a decrease of CD4+ and CD8+ T-lymphocytes in the thymus. Those birds infected with the attenuated virus in first instance and challenged with the virulent virus did not show these pathological effects in the thymus. In the bursa of Fabricius a severe depletion of lymphocytes was observed by immunohistochemistry in birds, infected with the virulent virus. Taken together it can be concluded that an infection with FAdV-4 has profound effects on cells, of the humoral and cell-mediated immune responses. The effects are much more severe in the birds infected with the virulent virus only indicating that the preceding infection with the attenuated virus reduces significantly the adverse effects induced by the virulent virus. 相似文献
10.
The immune effects of fowlpox virus (FPV) field isolates and vaccine strains were evaluated in chickens infected at the age of 1 day and 6 weeks. The field isolates and the obsolete vaccine strain (FPV S) contained integrated reticuloendotheliosis virus (REV) provirus, while the current vaccine strain (FPVST) carries only REV LTR sequences. An indirect antibody ELISA was used to measure the FPV-specific antibody response. The non-specific humoral response was evaluated by injection of two T-cell-dependent antigens, sheep red blood cells (SRBC) and bovine serum albumin (BSA). There was no significant difference in the antibody response to FPV between chickens infected with FPV various isolates and strains at either age. In contrast, antibody responses to both SRBC and BSA were significantly lower in 1-day-old chickens inoculated with field isolates and FPV S at 2-3 weeks post-inoculation. Furthermore, cell-mediated immune (CMI) responses measured by in vitro lymphocyte proliferation assay and in vivo using a PHA-P skin test were significantly depressed in chickens inoculated with field isolates and FPV S at the same periods. In addition, thymus and bursal weights were lower in infected chickens. These immunosuppressive effects were not observed in chickens inoculated with the current vaccine strain, FPVST, at any time. The results of this study suggest that virulent field isolates and FPV S have immunosuppressive effects when inoculated into young chickens, which appeared in the first 3 weeks post infection. REV integrated in the FPV field isolates and FPV S may have played a central role in the development of immunosuppression. 相似文献
11.
Gehad AE Mashaly MM Siegel HS Dunnington EA Siegel PB 《Veterinary immunology and immunopathology》1999,68(1):13-24
Chickens from third generation matings of lines of chickens selected for high (HA) and low (LA) antibody production to sheep red blood cells (SRBC) and typed for MHC genotypes B13/13, B13/21, and B21/21 were used in this study. Chickens from both lines carried all the three genotypes B13/13, B13/21, and B21/21. To study T- and B-lymphocytes mitogenic activity, 12-week-old female chickens were injected intravenously with 0.2 ml of 9% SRBC and spleens were collected at 0, 6 h, and 6 day post-antigen injection (pAg). Isolated lymphocytes were incubated with either Concanavalin-A (Con-A) for T-cell activity, or Pokeweed mitogen (PWM) for B-cell activity and thymidine 3H uptakes were measured. To study the Interleukin-2 (IL-2)-like activity in the same lines and genotypes, splenic lymphocytes from 12-week-old chickens were passed through nylon wool columns to enrich the T-cell population. After a 24 h incubation with Con-A, the conditioned media (CM) were collected. The CM were tested for IL-2 like activity by determining whether they altered the proliferation of Con-A stimulated T cells. This proliferation effect was then compared to that of a reference conditioned media (RCM) prepared from K-strain birds and that were used as the standard for the assay. There was no significant difference (p > 0.05) in IL-2 like activity between HA and LA lines, however, the LA was significantly higher than HA (p < 0.05) in T- and B-cell mitogenic activity. The genotype B13/13 had significantly higher (p < 0.05) IL-2 like activity than the B21/21. The genotype B13/13 was also significantly higher (p < 0.05) in T- and B-cell mitogenic activity than the B21/21. At 0 h, pAg T- and B-mitogenic activity was significantly higher (p < 0.05) than 6 h. In summary, our results indicate that although the birds were selected for high antibody production to SRBC, their lymphocyte mitogenic activity was lower than those selected for low antibody production. Hence, humoral and cell-mediated immune responses appear to be under different genetic controls, and that selection for greater humoral response may be at the expense of cellular responses. Our results also suggest differences in IL-2 like activity production between chickens carrying different MHC B-haplotypes, and that genetic control of such activity is possibly linked to the MHC genes. 相似文献
12.
本试验旨在研究饲粮不同粗蛋白质水平对26～41周龄的鲁西斗鸡生产性能及蛋品质的影响。试验选用26周龄(1.952±0.288)kg健康的鲁西斗鸡200只,随机分为4组,每组5个重复,每个重复10只。试验采取单因素试验设计,4个饲粮粗蛋白质水平依次为:14.0%、15.5%、17.0%和18.5%,各组均限饲,且投料量一致。试验期为16周。结果表明:在鲁西斗鸡产蛋期(26～41周龄),饲粮粗蛋白质水平对平均蛋重没有显著影响(P>0.05)。在试验前期(26～29周龄),饲粮粗蛋白质水平对平均周产蛋量、产蛋率和料蛋比均无显著影响(P>0.05);在试验中期(30～37周龄),30～33周龄17.0%饲粮粗蛋白质水平组平均周产蛋量显著高于其他各组(除30～31周龄15.5%饲粮粗蛋白质水平组外)(P<0.05),30～31周龄和36～37周龄产蛋率显著高于14.0%组和18.5%组(P<0.05),32～35周龄产蛋率显著高于15.5%组(P<0.05),但是各组间30～37周龄料蛋比差异不显著(P>0.05);在试验末期(38～41周龄),18.5%饲粮粗蛋白质水平组平均周产蛋量显著高于其他各组(P<0.05),产蛋率显著高于14.0%组和15.5%组(P<0.05),料蛋比显著低于15.5%组(P<0.05)。此外,33周龄时,随着饲粮粗蛋白质水平提高,蛋黄颜色有下降趋势(P=0.09);41周龄时,17.0%和18.5%饲粮粗蛋白质水平组蛋白高度和哈氏单位显著高于14.0%组和15.5%组(P<0.05)。综合以上结果,鲁西斗鸡产蛋期适宜的饲粮粗蛋白质水平:前期(26～29周龄)为14.0%;中期(30～37周龄)为17.0%;后期(38～41周龄)为18.5%。 相似文献
13.
Khetani TL Nkukwana TT Chimonyo M Muchenje V 《Tropical animal health and production》2009,41(3):379-384
The objective of the current study was to determine the effect of quantitative feed restriction on the performance of broilers.
A total of 270 unsexed broilers were randomly allocated to three treatments: with no feed restriction (T1), one week (T2)
and two (T3) weeks of feed restriction from 22 days of age and then fed ad libitum until the age of 42 days. Treatments were replicated three times with 30 birds per replicate. Birds were fed with starter,
grower and finisher diets. The feed consumed and body weights were recorded every week from the third to the sixth week. The
average daily gain (ADG), average daily feed intake (ADFI) and the feed conversion ratio (FCR) were computed for each week.
At Week 6, body weights of T3 birds were similar (P > 0.05) to those of T1 and T2 birds. There were also no treatment effects on the ADG at Week 6. In addition, no treatment effects
(P > 0.05) were observed on ADFI at each stage of growth. Since ADFI and FCR were similar among the three groups, it was concluded
that feed restriction by limiting the time to eat was not successful. There was also no evidence of compensatory growth in
the restricted groups. 相似文献
14.
Four different protocols were tested for the induction of IgA deficiency in chickens: (I) inoculation of anti-alpha intra-peritoneally (i.p.) on alternate days after hatching up to a period of three weeks; (II) bursectomy within 6 h and at 24 h after hatching; (III) in-ovo injection of anti-alpha on the 17th day of embryonation followed by bursectomy at 24 h of hatch and a single injection of anti-alpha i.p. on the day of hatching; (IV) as in III above but bursectomy within 6 h of hatch, followed by three further injections of anti-alpha on days 3, 10 and 34 after hatching. Treatment (I) produced temporary dysgammaglobulinemia during the period of treatment. Bursectomy at 24 h of hatch rendered 75% of the chicks IgA deficient up to four weeks of age. Early bursectomy within 6 h of hatch resulted in substantial improvement of IgA suppression. Such chicks, when tested at 4, 6 and 10 weeks of age, were found to be 81, 72 and 58.3% IgA deficient, respectively. With treatment (III) all the treated birds were IgA deficient at four weeks of age. However, as the birds grew older, IgA appeared in the serum so that at the age of 12 weeks only 27.3% were deficient. Treatment (IV) completely suppressed the IgA system of 13 out of 14 chickens. These chickens lacked both serum and secretory IgA as well as IgA-containing cells in their intestinal mucosa. Both IgG and IgM continued to be produced. 相似文献
15.
K. O. Ali U. T. Brenøe 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2013,63(4):246-252
Three genotypes of chickens including one commercial broiler (CB) and two others from the Norwegian gene bank [Barred Plymouth Rock (BPR) and Jærhøn (JH)] were raised from 1 day to 20 weeks of age with a free choice of a commercial starter ration and whole-grain wheat. Body weights and pen-feed intakes were recorded every 2 weeks. The weight–age data were fitted to a Gompertz growth equation where, among other parameters, adult body weights were estimated and used for size scaling. The heavier CB chickens consumed more food (starter and wheat) than the other two genotypes. The maximum proportions of whole-grain wheat in the diet were 0.56, 0.68 and 0.75 for BPR, CB and JH birds, respectively. Although the proportions of whole-grain wheat were similar between the genotypes as age progressed, their maintenance requirement and feed intakes relative to body weight suggested a major genetic role and a possible interplay of both genetic potential and body size. 相似文献
16.
Maurice DV Lightsey SF Abudabos A Toler JE 《Journal of animal physiology and animal nutrition》2002,86(11-12):383-388
The inconsistent beneficial responses to dietary ascorbic acid (AsA) may be due to dietary factors that alter biosynthesis or tissue turnover of AsA. It has been suggested on the basis of altered tissue AsA that dietary fluoride is a determinant of biosynthesis in chickens. Fluoride may enter the food chain of poultry via industrial contamination, feed ingredients and drinking water. The goal of this study was to ascertain whether dietary fluoride at 300 mg/kg influences l-gulonolactone oxidase (GLO) activity in commercial meat-type chickens. The experimental diet was fed from day-old to 3 weeks and responses measured. Growth and feed conversion were not affected by fluoride in the diet. Dietary fluoride neither inhibited nor enhanced GLO activity nor did it increase or decrease AsA concentration in plasma, liver, kidney, adrenal gland and muscle (pectoralis major). Tissue AsA concentration in ascending order was adrenal > liver > kidney > pectoralis major > plasma. The results are consistent with that reported for the rat and calculations based on the results eliminate fluorine contamination for the inconsistent responses of immature chickens to dietary AsA. 相似文献
17.
M. M. Fathi T. A. Ebeid I. Al-Homidan N. K. Soliman O. K. Abou-Emera 《British poultry science》2017,58(5):512-516
1. The objective of the study was to evaluate the potential effects of dietary probiotic supplementation and stocking density and their interaction on growth performance, humoral and cellular immune responses of broiler chickens raised under hot climate conditions.
2. A total of 1800 1-d-old unsexed broiler chicks (Ross 308) were allocated in a completely randomised 3 × 2 factorial design, with three concentrations of dietary probiotic (0, 200 and 400 mg/kg) containing 4 × 109 cfu/g of Bacillus subtilis and two stocking densities (12 or 18 birds/m2) in a total of 6 treatment subgroups.
3. Dietary probiotic and stocking density had no significant effect on live body weight, feed consumption and feed conversion ratio.
4. Dietary probiotic supplementation had a positive effect on serum immunoglobulin M (IgM) and cell-mediated immunity when compared to the control at 6 weeks of age, whereas serum immunoglobulin A (IgA) and immunoglobulin Y (IgY) were improved, but not significantly so. Dietary probiotic and stocking density had no effect on relative weights of the bursa of Fabricius and spleen.
5. Dietary probiotic supplementation had a positive significant effect on serum IgM concentration and cell-mediated immunity without penalising growth performance in broilers raised under high ambient temperature. 相似文献
18.
1. The present study examined the effects of the addition of 100 mg/kg L-carnitine to the basal starter (containing 17.8 mg/kg L-carnitine) and finisher (containing 22.9 mg/kg L-carnitine) diets on performance, organ weights and plasma hormone and metabolite concentrations of male and female broiler chickens. The broiler chickens were reared either in a room with a normal temperature (NT) program or with a low temperature (LT) program (rapid decrease from 28 degrees C to 20 degrees C at 14 d of age). 2. Broiler chickens reared under the LT schedule consumed more food and attained a greater body weight at 42 d of age than their counterparts reared under NT schedule, without any difference in food efficiency or abdominal fat content. Dietary L-carnitine supplementation had no significant effects on any of these production parameters, except for a reduction in the abdominal fat content of female NT chickens. However, the LT schedule and dietary L-carnitine supplementation greatly increased absolute and proportional heart weights. The elevated heart weights were not due to right ventricle hypertrophy. 3. Both the LT program and L-carnitine supplementation increased circulating plasma triiodothyronine concentrations. There were also some transient effects of both experimental variables on plasma growth hormone, glucose and triglyceride concentrations. 4. L-carnitine did not improve broiler performance. However, this result does not mean that L-carnitine supplementation cannot have beneficial effects in other circumstances. In view of the elevated proportional heart weights, it can also be argued that L-carnitine is a potential agent for reducing the incidence of metabolic diseases in broiler chickens. 相似文献
19.
Growth and haematological response of indigenous Venda chickens aged 8 to 13 weeks to varying dietary lysine to energy ratios 
下载免费PDF全文
下载免费PDF全文 O. J. Alabi J. W. Ng'ambi E. F. Mbajiorgu D. Norris M. Mabelebele 《Journal of animal physiology and animal nutrition》2015,99(3):436-441
The effect of feeding varying dietary lysine to energy levels on growth and haematological values of indigenous Venda chickens aged 8 – 13 weeks was evaluated. Four hundred and twenty Venda chickens (BW 362 ± 10 g) were allocated to four dietary treatments in a completely randomized design. Each treatment was replicated seven times, and each replicate had fifteen chickens. Four maize–soya beans‐based diets were formulated. Each diet had similar CP (150 g/kg DM) and lysine (8 g lysine/kg DM) but varying energy levels (11, 12, 13 and 14 MJ ME/kg DM). The birds were reared in a deep litter house; feed and water were provided ad libitum. Data on growth and haematological values were collected and analysed using one‐way analysis of variance. Duncan's test for multiple comparisons was used to test the significant difference between treatment means (p < 0.05). A quadratic equation was used to determine dietary lysine to energy ratios for optimum parameters which were significant difference. Results showed that dietary energy level influenced (p < 0.05) feed intake, feed conversion ratio, live weight, haemoglobin and pack cell volume values of chickens. Dry matter digestibility, metabolizable energy and nitrogen retention not influenced by dietary lysine to energy ratio. Also, white blood cell, red blood cell, mean corpuscular volume, mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration in female Venda chickens aged 91 days were not influenced by dietary lysine to energy ratio. It is concluded that dietary lysine to energy ratios of 0.672, 0.646, 0.639 and 0.649 optimized feed intake, growth rate, FCR and live weight in indigenous female Venda chickens fed diets containing 8 g of lysine/kg DM, 150 g of CP/kg DM and 11 MJ of ME/kg DM. This has implications in diet formulation for indigenous female Venda chickens. 相似文献
20.
Pirgozliev V Bedford MR Oduguwa O Acamovic T Allymehr M 《Journal of animal physiology and animal nutrition》2012,96(1):52-57
Thirty-two Ross 308 male broiler chickens were used in a precision feeding assay to investigate the effect of exogenous phytase (EC 3.1.3.26) on dietary apparent metabolisable energy (AME), dry matter digestibility (DMD) coefficient, nitrogen (NR), amino acid and mineral retentions. The excretion of endogenous losses measured as sialic acid (SA) was also determined. Four dietary treatments (control (C), C + 250 FTU (phytase units per kg feed), C + 500 FTU, and C + 2500 FTU) were studied with each treatment replicated eight times in randomised complete block design. Diets were formulated to be nutritionally adequate with the exception of available P content (2.3 g/kg non-phytate P). Over the 48-h collection period, the phytase fed birds retained 29.3 mg more Na and 2.3 mg more Zn (p < 0.05) than the control fed birds, with the relationship between phytase dose and Na and Zn retention being best described by a linear function (p < 0.05 and p < 0.001, for Na and Zn, respectively). Phytase supplementation did not have an effect on dietary AME, DMD and NR. However, increasing the dose of phytase led to a linear increase in dietary amino acid retention (p < 0.05). Dietary phytase decreased total sialic acid excretion in a linear fashion (p < 0.05). It can be concluded that supplementary phytase increases the retention (reduces the excretion) of dietary Zn and Na in broiler chickens. The beneficial effects of the addition of exogenous phytases to poultry diets seems to be mediated through improved dietary nutrients absorption and reduced endogenous losses. 相似文献