Hasan Ghahri

The aim of present study was to investigate the beneficial effect of chromium (III) picolinate (CrPic) and chromium (III) picolinate nanoparticles (NCrPic) addition on growth performance, stress-related hormonal changes, and serum levels of various immunity biomarkers, as well as the gene expression of IFN-γ in broilers exposed to heat stress conditions. Treatments included T1 which received the basal diet with no feed additive; T2 exposed to heat stress; T3, T4, and T5 containing 500, 1000, and 1500 ppb CrPic; as well as T6, T7, and T8 containing 500, 1000, and 1500 ppb NCrPic, respectively. After 2 weeks from CrPic and NCrPic supplementation, IFN-γ mRNA expression was assayed using the RT-PCR technique. The results showed that the lower body weight, daily weight gain, daily feed intake by heat stress, and the feed conversion ratio were recovered remarkably by CrPic and NCrPic supplements. The stress-elevated levels of cortisol and immunoglobulin were reduced significantly using CrPic and NCrPic supplementation (P ≤ 0.05). The gene expression profile showed that the upregulated expression of IFN-γ was regulated by the addition of CrPic and NCrPic, in particular, to the diet; however, a full downregulation of IFN-γ expression was observed after week 2 of NCrPic supplementation. In conclusion, the results indicated that nanoparticle supplementation could be effective in reducing heat stress–induced detrimental alterations, thereby attributing to substantial changes to the immune system, including IFN-γ expression.

This experiment was carried out to investigate the effects of different levels chromium picolinate (CrPic) and chromium nanoparticles (nano-Cr) on the performance and immune function of broilers under heat stress condition. A total of 320 Ross 308 broiler chicks (from 21 to 42 days) were assigned randomly into eight treatment groups (four replicates per treatment, and 10 chicks per replicate) and be reared at either thermoneutral (21 ˚C) or heat stress (36 ◦C). The treatments were control (T1) group without supplementation and heat stress, T2 as a heat stress group without supplementation, T3, T4 and T5 groups which were supplemented with 500, 1000 and 1500 ppb CrPic in diet with heat stress, respectively and T6, T7 and T8 groups which were supplemented with 500, 1000 and 1500 ppb nano-chromium in diet under heat stress, respectively. Supplementation of chromium and nano-chromium improved performance including weight gain and feed conversion ratio of heat-stressed chickens. Antibody titers against avian influenza (AI) and infectious bronchitis (IB) at 21 to 42 days of age in broilers fed supplemental chromium and nano-chromium were higher than broiler chickens fed control diet (p < 0.05). Nano-chromium supplementation at level of 1000 ppb and CrPic at level of 1500 ppb improved the antibody titers against AI and IB of broilers under heat stress conditions. It can be concluded from these findings that dietary supplementation of CrPic and nano-Cr can improve performance and antibody titers against AI and IB under heat stress conditions in broilers.

An experiment was conducted from 1 to 42 day post hatching to determine the effects of a microbial phytase (Natuphos) and glycanase preparations with predominantly xylanase and β-glucanase (Feedzyme) on the performance, serum mineral levels and antibody titer against newcastle disease, of broilers fed nutritionally marginal diets. A completely randomized experimental design was used, and chicks were divided into 5 treatment groups, with 4 replicates per treatment and 10 chicks per replicate. Diets were corn-wheat-soybean meal based with the same nutritional specifications, differing only in the concentration of Ca and nonphytate P (Ca-nPP). Treatments were: (1) diet with the energy of 2900 kcal/kg and 0.63% Ca and 0.28% available P, without enzyme (CTL+);T2) diet with the energy of 2900 kcal/kg and 0.63% Ca and 0.28% available P, without enzyme (CTL−); 3, 4 and 5) diet with the energy of 2900 kcal/kg and lower level of Ca and P (experimental group 2) respectively comprising 600,800,1000 phytase unit/kg of diet from Natuphous and 42,70,98 Xylanase unit/kg and 60,100,140 β-glucanase unit/kg of diet from feedzyme. Antibody titers against Newcastle disease were increased by incremental phytase and xylanase addition in experiments. These finding indicates that broilers consuming a ME, Ca, P-deficient corn-soybean meal-wheat diet can achieve maximum humoral immunity when phytase, xylanase and β-glucanase is supplemented to 1000, 98 and140 unit/kg diet. Performances of chicks fed with low-Ca-nPP diets plus phytase, xylanase and glucanase were comparable to those obtained with the low-Ca-nPP and adequate-Ca-nPP diets. Enzymes supplementation increased plasma Ca level (P > 0.05) but had no significant effect on plasma P level. Key words: Phytase, glycanase, newcastle disease, performance, immunity, broiler.

The effect of mannanoligosaccharides (MOS) and Humate (HU) in broiler diets on antibody titers against Avian Influenza virus (AIV) was evaluated. A completely randomized experimental design was used, and chicks were divided into 8 treatment groups, with 4 replicates per treatment and 10 chicks per replicate. Treatments were: 1) negative control group (CTL−), neither vaccinated against AIV nor given additives; 2) positive control (CTL+) or broilers were vaccinated against AIV + 0 additives; 3,4 and 5) CTL+ plus diet supplemented with 0.1, 0.2 and 0.3% HU, respectively; 6,7 and 8) CTL+ plus diet supplemented with 0.1, 0.2 and 0.3% MOS, respectively. For antibody analyses, blood samples were weekly collected by wing veins and the titers of antibody against AIV were measured by haemagglutination-inhibition test (HI). Compared to the positive control, the antibody titers against AIV were determined significantly lower in negative control group from 28 to 42 days of age. The inclusion of MOS resulted in increased antibody titers against AIV in the fourth, fifth and sixth weeks of age. MOS was effective in stimulating the humoral immune responses against AIV vaccine viruses. This study demonstrated an increase in the antibody titers in broilers fed diets containing 0.3% HU. In general, results of this study demonstrated that MOS proved to be much more effective on antibody production against AIV in broiler chicks than HU. Immune function could be modified with dietary HU and MOS supplementation.

A study was conducted to determine the efficacy of esterified glucomannan, sodium bentonite, and humic acid in counteracting the toxic effects of aflatoxin in a naturally contaminated diet fed to broilers. Seven-day-old chicks were randomly assigned to 1 of the 9 dietary treatments. The treatments were as follows: 1) control; 2) naturally contaminated diet with aflatoxin; 3, 4, 5, 6, and 7) naturally contaminated diet with aflatoxin supplemented with 0.2%, 0.4%, 0.6%, 0.8%, and 1.0% humic acid, respectively; 8 and 9) naturally contaminated diet supplemented with 0.5% sodium bentonite and 0.1% esterified glucomannan, respectively. Compared with the control, the naturally contaminated diet significantly increased feed consumption and resulted in poor feed efficiency. Increased relative weights of liver and decreased relative weights of bursa of Fabricius were observed in chicks fed the naturally contaminated diet. Further, feeding a contaminated diet was associated with significant decreases in serum albumin, total protein, uric acid, and cholesterol. Compared with the control, the naturally contaminated diet significantly increased the activities of \gamma-glutamyl transferase, lactate dehydrogenase, and aspartate amino transferase. Humic acid showed protective effects on feed efficiency and against liver and bursa of Fabricius damage, as well as some of the serum enzyme activities and serum biochemical changes associated with aflatoxin toxicity.

A study was conducted on the impact of aflatoxin (AF) and mycotoxin binders on immunization against Infectious Bursal Disease (IBD) and Infectious Bronchitis (IB) in chickens. Broiler chicks (7-day-old) were randomly assigned to 9 dietary treatments with 4 replicates of 12 chicks each. Treatments were 1) control; 2) diet containing corn naturally contaminated with AF (NCD); 3) NCD + 0.2% Farmagülatör DRYTM humate (FH); 4) NCD + 0.4% FH; 5) NCD + 0.6% FH; 6) NCD + 0.8% FH; 7) NCD + 1% FH; 8) NCD + 0.5% sodium bentonite (SB); and 9) NCD + 0.1% esterified glucomannan (E-GM). Data were evaluated with ANOVA for a complete randomized design, using the general linear models procedure of SAS software. Compared to control diet; the antibody titers of IB and IBD were significantly lower in the 254 ppb aflatoxin fed chicks from 28 to 35 days of age. The addition of E-GM, SB, and FH to the aflatoxin-containing diet significantly ameliorated the adverse effects of aflatoxin on IBD and IB antibody titers, but FH supplementation to the contaminated diet with aflatoxin proved to be much more effective in the amelioration of the adverse effect of aflatoxin on humoral immunity against IB.