Dose-responses of zinc as zinc-methionine supplements on antioxidant status, hematological parameters, immune response and the expression of IL-4 and IL-6 genes of ewes in the hot season.

This study was implemented to evaluate the effects of different zinc doses as Zinc-Met supplement (Zinpro®) on the antioxidant status, blood immune cells, antibody titers, and the expression of IL-4 and IL-6 genes of ewes in the hot season. In a completely randomized design, 24 ewes were assigned to treatments as follow: 0, 15, 30 and 45 mg/kg zinc as Zinc-Met supplementation for 40 days in region with 40 °C and vaccinated against food-and-mouth disease as an immune challenge at day 30, and then blood samples were collected on day 40. Ewes were fed a basal diet containing 29.9 mg zinc/kg. The highest activity of the antioxidant enzyme and the lowest lipid peroxidation values were found in ewes receiving 30 and 45 mg/kg zinc following a linear trend. The highest lymphocytes count and antibody titers were found in ewes received 30 mg zinc/kg. There were no significant differences among treatments for the relative expression of genes. In overall, zinc supplementation non-significantly up-regulate interleukin-4 and down-regulate interleukin-6. It was concluded that zinc supplementation as Zinc-Met could enhance the antioxidant status and immune response of ewes under heat stress; supplementation of diet with 30 mg zinc/kg (300 mg/kg Zinpro®) appeared to be the most effective dose.

Effects of live and autolyzed yeast supplementation during transition period on ruminal fermentation, blood attributes, and immune response in dairy cows under heat stress condition.

This study was conducted to compare nutrient digestibility, performance and immune response of dairy cows received live and autolyzed yeast during the transition period in high ambient temperature. Cows (n = 25) were randomly divided and received a basal diet with or without live yeast or autolyzed yeast as on top three weeks pre-parturition until three weeks post-parturition. The Control group received a basal diet without yeast products; other groups received 0.5 g live yeast; 1.0 g live yeast; 10 g autolyzed yeast and 20 g/d/head autolyzed yeast. Live yeast resulted in higher nutrient digestibility compared with autolyzed yeast and the control. Methane production was the highest in autolyzed yeast and the lowest in live yeast. Average milk production was the highest in cows that received live yeast. The highest IgG level was for cows that received autolyzed yeast at a dose of 20 g/d/head. Live yeast had no significant effect, but autolyzed yeast increased the relative expression of γ-Interferon and interleukin-2 as compared with the control group. It was concluded that live yeast at a dose of 1.0 g/d/head could influence ruminal fermentation and milk production, but autolyzed yeast at a dose of 20 g/d/head could influence the immune response of dairy cows during the transition period and heat stress.

Inflammatory genes expression and calf responses to different dietary grains (steam flaked corn vs steam-rolled barley) and protein sources (pelleted soybean meal vs pelleted canola meal).

This study aimed to investigate the effects of grains, and protein sources in the starter diet on daily gain, pro- and anti-inflammatory genes expression, ruminal volatile fatty acid (VFA) concentration, and blood metabolites in the dairy calves. Forty Holstein calves were randomly assigned to treatments in a 2 × 2 factorial arrangement with the factors of grain source (steam-flaked corn, CG vs. steam-rolled barley, BG) and pelleted protein source (soybean meal, SBM vs. canola meal, CM). The daily gain of calves who fed with SBM was higher than those fed with CM. Total VFA concentration in the rumen of calves fed with CG was greater than BG at day 35 (p < 0.05), and calves receiving SBM had higher total VFA concentration than calves fed with CM. The relative expression of tumor necrosis factor-α and interleukin-1ß genes were significantly decreased in the calves fed with BG and CM compared to calves fed with CG and SBM. Calves receiving the starter diet based on BG had the highest (p < 0.05) gene expression of interferon-γ. Feeding calves with SBM is recommended because it resulted in a greater daily gain than CM. Complete replacement of SBM with CM, and CG with BG is not recommended in dairy calves.

The effects of thymol, oxalic acid (Api-Bioxal) and hops extract (Nose-Go) on viability, the Nosema sp. spore load and the expression of vg and sod-1 genes in infected honey bees.

This study was done to investigate the effects of thymol, fumagillin, oxalic acid (Api-Bioxal) and hops extract (Nose-Go) on Nosema sp. spore load, the expression of vitellogenin (vg) and superoxide-dismutase-1 (sod-1) genes and mortality of bees infected with N. ceranae. Five healthy colonies were assigned as the negative control, and 25 Nosema sp. infected colonies were assigned to five treatment groups including: the positive control: no additive to sirup; fumagillin 26.4 mg/L, thymol 0.1 g/L, Api-Bioxal 0.64 g/L and Nose-Go 5.0 g/L sirup. The reduction in the number of Nosema sp. spores in fumagillin, thymol, Api-Bioxal and Nose-Go compared to the positive control was 54, 25, 30 and 58%, respectively. Nosema sp. infection in all infected groups increased (p < .05) Escherichia coli population compared to the negative control. Nose-Go had a negative effect on lactobacillus population compared to other substances. Nosema sp. infection decreased vg and sod-1 genes expression in all infected groups compared to the negative control. Fumagillin and Nose-Go increased the expression of vg gene, and Nose-Go and thymol increased the expression of sod-1 gene than the positive control. Nose-Go has the potential to treat nosemosis if the necessary lactobacillus population is provided in the gut.

Hematological parameters, antioxidant status, and gene expression of γ-INF and IL-1ß in vaccinated lambs fed different type of lipids.

This study was aimed to evaluate the effects of vegetable oils as calcium salt on immune responses and the expression of immune-related genes in vaccinated lambs. Twenty-four lambs (35 kg body weight, 6 months old) were assigned to four treatments with six replicates in a completely randomized design for 40 days. Four concentrates were formulated in which the calcium salts of palm oil, canola oil, corn oil, and flaxseed oil were used. On day 30 of the experiment, lambs were vaccinated by a dose of foot-and-mouth disease virus. The blood samples were collected from jugular vein 10 days after vaccination. The level of malondialdehyde and the activity of liver enzymes were the highest in lambs receiving corn oil and the lowest in lambs receiving flaxseed oil. The highest lymphocytes and the lowest neutrophil percentages were observed in lambs receiving flaxseed oil. There was a significant difference among treatments for the relative genes expression. Flaxseed oil significantly upregulated interferon-γ and corn oil upregulated interleukin-1ß. The highest titer against foot-and-mouth disease virus was related to lambs receiving flaxseed oil, and the lowest titer was related to lambs that received corn oil. Flaxseed oil had more beneficial effects on immune response than other oils.

Effect of palmitic, linoleic and α-linolenic acids on blood cells count and interleukin-4, 8 genes expression in lambs experimentally infected with foot and mouth disease virus.

The current research was conducted to study the effects of different saturated and poly-unsaturated fatty acid sources in diets on immune responses of lambs experimentally infected with foot and mouth disease virus. A total of fifteen Sangsari male lambs with an average body weight of 48 ± 2 kg and an average age of 8 ± 1 months were randomly allocated to one of three experimental treatments: (1) PalOil group received a calcium soap of palm oil fatty acids in the diet as source of palmitic acid (16:0), (2) SunOil group received a calcium soap of sunflower oil fatty acids in the diet as source of linoleic acid (n-6 18:2), and (3) LinOil group received a calcium soap of linseed oil fatty acids in the diet as source of α-linolenic acid (n-3 18:3). The greatestand the least expression of IL-4 mRNA were measured in SunOil and LinOil groups, respectively. Expression of IL-8 mRNA was greater in SunOil treatment when compared with PalOil and LinOil groups. In conclusion, the results of the study confirmed that inclusion of α-linolenic acid in virally infected lambs'diet results in lower expression of IL-4 and IL-8 mRNA.

Effects of enzymatically hydrolyzed yeast supplementation on blood attributes, antioxidant status and gene expression of cytokines in vaccinated dairy cows.

This study was done to assess the effects of hydrolyzed yeast on blood cells counts, antioxidant status and gene expression of pro-inflammatory and anti-inflammatory cytokines of vaccinated dairy cows. Twenty Holstein lactating dairy cows were randomly divided into four groups received basal diet without (control) and with 10, 20 and 30 g/d/head of hydrolyzed yeast. Cows were vaccinated against foot and mouth disease virus at day 10 and blood samples were taken 10 days after. Cows received hydrolyzed yeast at doses of 20 and 30 g/d/head had the lowest and those in the control group had the highest malondialdehyde concentration. Cows received hydrolyzed yeast at dose of 20 g/d/head had the highest lymphocyte and the lowest neutrophil/lymphocyte ratio. IL-1ß and TNF-α downregulated and INF-γ up-regulated in cows received different doses of hydrolyzed yeast. The lowest expression of IL-1ß and TNF-α and the highest expression of INF-γ was for cows received hydrolyzed yeast at dose of 20 g/d/head. The highest titers against foot and mouth disease virus were for cows received hydrolyzed yeast at dose of 20 g/d/head and the lowest titer was for the control group. Supplementation of 20 g/d/head hydrolyzed yeast recommended in vaccinated cows.

Effects of different fat sources (saturated and unsaturated) on reproductive performance and biological indices of ewes during flushing period.

This study was conducted to evaluate the effect of feeding different sources of fat during flushing period on the reproductive performance, lambing percent, and twin numbers of Afshari ewes. A total of 84 ewes (mean weight 48 ± 3 kg; age: 3-4 years) were divided into seven groups of 12 animals and received flushing-specific rations for 5 weeks. The control group just received a basic ration (non-flushing). Lipid sources were calcium salt of palm oil (CaP), pure palm oil (PO), calcium salt of flaxseed (CaFL), calcium salt of sunflower oil (CaSF), flaxseed oil (FLO), and sunflower oil (SFO). Estrous cycles were synchronized in all ewes using 14-day CIDRs followed by 400-IU PMSG injection at the time of CIDR removal. Fertility and lambing percent were higher in ewes fed with diets containing calcium salts of flaxseed and SFO, as compared to other treatments. Total number of lambs in flushing treatments was significantly higher than that in the control group (p < 0.01). Serum cholesterol and progesterone levels were significantly greater in omega-3 (CaFL) and omega-6 (CaSF) treatments relative to other treatments (p < 0.01). It was concluded that supplementing the flushing diet with calcium salts of fatty acids (CSFA) increased blood metabolites and hormones related to reproductive performance; and improved fertility, lambing rate and ewes of CaFL treatment have the highest number of lambs (16 lambs) between different groups. Using saturated and unsaturated fatty acids, especially in their CSFA forms during flushing period, could improve the reproduction problems induced by progesterone deficiency, lack of durability of the fetus due to hormonal instability, and abortion control factors.

Effect of cyclical cold stress during embryonic development on aspects of physiological responses and HSP70 gene expression of chicks.

The objective of the present study was to evaluate the effects of cyclical lower incubation temperature at different embryonic ages on the hatchability, body and organs weights, thyroid hormones, and liver HSP70 gene expression of newly hatched chicks. In a completely randomized design, fertile eggs of a broiler breeder (34 weeks of age) were assigned to three treatment groups with six replicates and 145 eggs per each. The treatment groups were as: control group (C) that eggs were incubated at 37.6°C during the whole incubation period; incubation temperature was decreased to 36°C for 3h per day at embryonic age from 12 to 14 (T1); and incubation temperature was decreased to 36°C for 3h per day at embryonic age from 15 to 17 (T2). No significant difference was found among treatments for hatchability (P>0.05). There were no differences (P>0.05) among treatments for body weight and liver weight, while heart weight of chicks in T1 and T2 groups were significantly higher than the control group (P<0.05). There were no differences (P>0.05) among treatments for the levels of thyroid hormones, however, the levels of both hormones tended to increase in chicks exposed to cold stress (T1 and T2). Chicks in T2 group had higher liver HSP70 gene expression compared with those in T1 and the control group (P<0.05). Cold stress in both incubation periods had no significant effect on the plasma levels of aspartate aminotransferase and alanine aminotransferase. Treatments had no effect on the plasma levels of glucose, cholesterol and triglyceride. The results of this study suggest that cyclical lower incubation temperatures (36°C) at the embryonic age from day 15-17 could induce the liver HSP70 gene expression, without negative effects on the hatchability and body weight of hatched chicks.

Energy sources and levels influenced on performance parameters, thyroid hormones, and HSP70 gene expression of broiler chickens under heat stress.

The present study was conducted to evaluate the effects of energy sources and levels on body and organs weights, thyroid hormones, and heat shock protein (HSP70) gene expression in broilers under heat stress. In a completely randomized design, 600 1-day-old Cobb chickens were assigned to five dietary treatments and four replicates. The chickens were fed diet based on corn as main energy source and energy level based on Cobb standard considered as control (C), corn-based diet with 3 % lesser energy than the control (T1), corn-based diet with 6 % lesser energy than the control (T2), corn and soybean oil-based diet according to Cobb standard (T3), and corn and soybean oil-based diet with 3 % upper energy than the control (T4). Temperature was increased to 34 °C for 8 h daily from days 12 to 41 of age to induce heat stress. The chickens in T1 and T2 had lower thyroid hormones and corticosterone levels than those in C, T3, and T4. The highest liver weight was for C and the lowest one was for T4. The highest gene expression was found in chickens fed T4 diet, and the lowest gene expression was for those in T2 group. The highest feed intake and worse feed conversion ratio was related to chickens in T2. The chickens in T3 and T4 had higher feed intake and weight gain than those in C. The results showed that the higher energy level supplied from soybean oil could enhance gene expression of HSP70 and decline the level of corticosterone and thyroid hormones and consequently improved performance.

Study of male effect on feeding and estrus behavior of Afshari ewes.

This study was conducted to evaluate the male effect on the manifestation of estrus and feeding behavior of Afshari ewes during their breeding season. The study consists of 48 Afshari ewes, 3 years old, 67 ± 2 kg live weight, body condition score 3, along with 10 Afshari rams. The study was for a period of 6 weeks in a complementary randomized design. Ewes were equally divided into three treatments (T1, T2, and T3) along with a control (T4) with six animals in each group. Variable factors of treatments was the distance of the ram box (from the ewes), which was determined to be the T1(0-5 m), T2(10-15 m), and T3(25-30 m). Exposure of the ewes to the rams resulted in an earlier manifestation of estrus signs (p < 0.05). Moreover, the total recorded estrus signs were significantly affected by the distance from the rams (p < 0.05). The result of this study showed differences in feed intake of the ewes due to the distance from the rams (p < 0.05). In the other words, the distance of the ewes from the rams significantly affected feed intake of the Afshari ewes.

Effect of Organic Selenium Supplementation on the Antioxidant Status, Immune Response, and the Relative Expression of IL-2 and IFN-γ Genes in Ewes During the Hot Season.

This study was conducted to evaluate the effects of different doses of selenium (Se) from Sel-Plex© (selenium-enriched Saccharomyces cerevisiae yeast) supplement on the antioxidant status, the antibody titers against the foot-and-mouth disease virus, and the expression of interleukin-2 (IL-2) and interferon-γ (IFN-γ) genes in ewes during the hot season. Six ewes were kept at 25 °C and received basal diet (the negative control group), and 24 ewes were kept at 38 °C for 5 h per day and received no supplement (the positive control), 0.15, 0.30, and 0.45 mg Se/kg. Ewes in the positive control had higher (P<0.001) liver enzyme activity, malondialdehyde (MDA), and cortisol levels, and lower antibody titer than the negative control. The liver enzymes' lowest (P<0.001) activities were observed in ewes receiving 0.30 and 0.45 mg Se/kg. Ewes receiving 0.30 and 0.45 mg Se/kg had lower MDA levels than other treatments. Ewes receiving 0.30 and 0.45 mg Se/kg had higher (P<0.001) total antioxidant capacity levels than those receiving 0.15 mg Se/kg and the positive control. Se-supplemented groups had lower (P<0.001) relative expression of IL-2 and higher (P<0.04) expression of IFN-γ than the positive control. The antibody titer was the same in the positive control and the group receiving 0.15 mg Se/kg. Ewes fed a diet with 0.30 and 0.45 mg Se/kg had higher (P<0.011) antibody titer than the positive control. The Se supplementation can reverse the decrease of antioxidant capacity and immune function caused by heat stress, and 0.3 mg Se/kg from Sel-Plex©is the best dose.

Effects of different lipid sources with or without a probiotic on gastrointestinal tract, immune system and blood parameters of chickens: An animal model.

The objective of this study was to determine the effects of different lipid sources, with or without a probiotic, on the gastrointestinal tract, immune system and blood parameters of Ross 308 male chickens. In this study, 360 one-day-old chickens were randomly allotted to six treatments with six replicates. Experimental diets were: (1) control (CTL); (2) a diet containing 30 g/kg lipid from tallow (CTL+TLW); (3) a diet containing 30 g/kg lipid from soybean oil (CTL+SO); (4) the basal diet plus a probiotic (CTL+PRO), (5) a diet containing 30 g/kg tallow plus probiotic (TLW+PRO); and (6) a diet containing 30 g/kg soybean oil plus probiotic (SO+PRO). The percentage of liver and jejunum in the treatments that used tallow alone or tallow with probiotics had a significant increase as compared to the control. The villus height and crypt depth of the ileum and villus height/crypt depth in the treatments that used soybean oil and probiotic alone had a significant increase compared to the control. The weight of the spleen, bursa of Fabricius, and thymus in the treatments that used probiotics had a significant increase compared to the control. The amount of alkaline phosphatase and alanine aminotransferase as well as triacylglycerol in the treatment containing probiotic and its mixture with soybean oil had the least significant difference with the control. The results showed that the use of soybean oil, probiotics, and their mixture can improve intestinal morphology, strengthen the immune system, and reduce liver enzymes in chickens.

Effects of Supplemental Chromium Nanoparticles on IFN-γ expression of Heat Stress Broilers.

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.

Spermatogonial stem cell survival in ram lambs following busulfan treatment.

To clarify the effect of busulfan on the depletion of spermatogonial stem cells (SSCs) from shal rams testis, in the first experiment, lambs were treated by intraperitoneal injection with 4 mg/kg busulfan. In the second experiment, different concentrations of busulfan (1, 2 and 4 mg/kg) were injected directly into both sides of the left testis. The testes of 8 lambs were collected by standard castration procedure for histological analysis five weeks after the treatments and the left testis of remaining lambs were collected after eight weeks and a two-time enzymatic digestion process was used to isolate SSCs. The results showed that all rams that had received intraperitoneal injections of busulfan died. But by testicular injecting of same dose of the drug, 40% of the animals died. The testicular injection of rams with 1, 2 and 4 mg/kg of busulfan resulted in a dose dependent decrease in testis size and also spermatocytes population after 5 weeks of treatments. From the results of colony formation 8 weeks after treatment with busulfan, it can be concluded that only in 1 and 2 mg/kg of busulfan, recovery of endogenous germ cells was performed. In conclusion, the results demonstrated that intra-testicular injections of busulfan (2 mg/kg) reduced spermatocytes population in ram testis within 5 weeks of treatments, and this effect was reversible within 8 weeks of injection. However, it was not recommended to inject 4 mg/kg busulfan into the peritoneal cavity or testis of lambs based on its side effects.

Therapeutic effects of organic zinc on reproductive hormones, insulin resistance and mTOR expression, as a novel component, in a rat model of Polycystic ovary syndrome.

OBJECTIVES: Zinc is an effective factor in the reproductive system. Insulin resistance (IR) is known as an important disorder in patients with polycystic ovary syndrome (PCOS). Mammalian target of rapamycin (mTOR), which controls key cell activities, in particular, is activated in disorders such as PCOS. The present study was conducted to observe the therapeutic effects of organic zinc on IR, mTOR gene expression, and pathogenesis of PCOS in a rat model induced-PCOS. MATERIALS AND METHODS: Experimental treatments were performed on control and treated groups, consisting of healthy controls (Control, water, and standard feed intake and daily injection of sesame oil alone), Polycystic control (PCO, injection of 4 mg/kg estradiol valerate (EV) for four weeks). Treated groups (PCO-ZM 25, PCO-ZM 75, and PCO-ZM 175) after 4 weeks of receiving EV, were daily given three levels of 25, 75, and 175 mg zinc methionine/kg BW for 15 days, respectively. RESULTS: Injection of EV dramatically increased body and ovarian weights, levels of LH, testosterone, estradiol, triglyceride, fasting insulin, fasting glucose, HOMA-IR, IGF-1, gene expression of mTOR, and number of cysts (P<0.05). It also reduced the level of progesterone, HDL-C, and the number of antral follicles (P<0.05). However, by increasing zinc-methionine application especially at 175 mg/kg BW, the induction effects of EV were improved on ovarian cysts (P<0.05). CONCLUSION: Organic zinc showed beneficial effects in the EV induced PCOS rats via decreased insulin resistance and mTOR expression, restored the hormonal profile, and decreased the number of cysts in the ovaries.

The Effects of Zinc Methionine on Reproductive and Thyroid Hormones in Rats with Polycystic Ovarian Syndrome.

BACKGROUND: Polycystic ovarian syndrome (PCOS) is an endocrine disorder in fertile women, which seems to be adversely affected by associated thyroid dysfunction. Zinc methionine (ZM) has positive effects on PCOS, but its concerted effects on PCOS and thyroid function have not been investigated. We evaluated the effects of ZM on reproductive and thyroid hormones and the number of follicles in rats with PCOS. MATERIALS AND METHODS: This study was conducted on 45 female rats, using sesame oil as control; PCOS animals administered with 0, 25, 75, and 175 mg/kg BW of ZM. Serum concentrations of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and thyroid function were investigated. Premature follicles (PMF), primary follicles (PF), preantral follicles (PAF), antral follicles (AF), corpus luteum (CL), and cystic follicles (CF) were assessed. RESULTS: PCOS decreased the concentrations of FSH and free T4, but increased the levels of LH, TSH, and LH/FSH ratio (ALL P < 0.05). ZM at a dose of 75 and 175 mg increased the level of FSH, free T4, and decreased LH, TSH, and LH/FSH ratio (ALL P < 0.05). Induction of PCOS decreased PMF, PF, PAF, AF, and CL, but increased CF (P < 0.05). PCOS treated groups (75 and 175 mg/kg) increased these follicle numbers and decreased CF compared to ZM 25 mg/kg and PCOS groups (Both P < 0.05). CONCLUSIONS: Although the induction of PCOS had a negative effect on reproductive and thyroid hormones and follicle numbers, ZM treatment (75 and 175 mg/kg) overcame the negative effects. A high dosage of ZM can alleviate the hormonal and cysts disturbances occurring in PCOS.

Immune Response of Salmonella Challenged Broiler Chickens Fed Diets Containing Gallipro®, a Bacillus subtilis Probiotic.

This study was conducted to investigate the effect of feeding a probiotic, Bacillus subtilis, on antibody titers against Newcastle and infectious bursal viruses in broiler chickens challenged with Salmonella enterica serotype Enteritidis. One hundred and sixty 1-day-old broiler chicks were randomly assigned to four treatments in a completely randomized design. The treatments were negative control, probiotic-treated group, challenged group, and challenged probiotic treated group. Salmonella challenging decreased (P < 0.05) the relative weights of spleen and bursa. Inclusion of probiotic to diet of challenged chickens increased the relative weight of spleen, but had no effect on the relative weight of bursa. There were no differences for the antibody titers of chickens between negative control and probiotic-treated group. Salmonella challenging decreased (P < 0.05) antibody titers against Newcastle and infectious bursal viruses. Improvements in the antibody titers were observed by the addition of probiotic to diet of these chickens. The results showed that dietary inclusion of probiotic had no significant effect on immune parameters of chickens at non-contaminated environment, display a greater efficacy at environment contaminated with pathogen and can improve immune responses of infected chickens.

Detection of Clostridium sp. and its Relation to Different Ages and Gastrointestinal Segments as Measured by Molecular Analysis of 16S rRNA Genes

The objective of this study was to establish a specific, sensitive and rapid PCR approach for the detection of Clostridium sp. at the genus level. Clostridium sp. in the duodenum, jejunum, ileum and cecum of broiler chickens were analyzed by 16S rRNA genes. The PCR detected the presence of Clostridium spp. in naturally contaminated intestinal samples. For the total gastrointestinal segments, 53.125, 65.625 and 59.375 percent samples were positive for naturally occurring Clostridium spp. at the ages 4, 14 and 30d, respectively. Analysis of the microbial contents indicated that Clostridium sp. was not consistently detected in all intestinal segments. These results can put in evidence the hypothesis that Clostridium spp. may be interfering in health and performance of chickens.

Clostridium spp. são organismos patogénicos com distribuição mundial, podendo estar presente nos seres humanos, em animais domésticos e em animais selvagens. Estas bactérias habitam geralmente o trato gastrintestinal. Os métodos bacteriológicos convencionais como a microscopia e a cultura têm limitações. O objetivo deste estudo foi de estabelecer uma metodologia específica, sensível e rápida como a ténica de PCR para a deteção de Clostridium spp. A presença de Clostridium spp. Foi pesquisada no duodeno, o jejunum, o íleo e o cecum de galinhas usando análise molecular de genes do rRNA 16S. A técnica de PCR usada neste trabalho detectou Clostridium spp. em amostras intestinais naturalmente contaminadas. Considerando o trato gastrintestinal total, 53.125, 65.625 e 59.375 por cento das amostras foram positivas para Clostridium nas idades 4, 14 e 30d respectivamente. A análise microbiana indicou que Clostridium spp. não foi detectado consistentemente em todos os segmentos intestinais. Os dados observados alertam para possíveis implicações significativas para a saúde e o desempenho das galinhas.