Effects of humic acid and organic acids supplements on performance, meat quality, leukocyte count, and histopathological changes in spleen and liver of broiler chickens.

The aim of the present study is to evaluate the effect of Humic Acid (HA), Organic Acids (OA), and their combination (HAOA) on the growth performance, meat quality, leukocyte count, and histopathological changes in the liver and spleen of broiler chickens. A total of 2100 one-day-old mix-sexed broiler chickens were randomly divided into 4 groups with 5 replicates per treatment using 105 birds per pen (pen is used as an experimental unit). Treatments were: 1) Control (basal diet without additives), 2) Basal diet +0.1% HA, 3) Basel diet +0.1% HA+ 0.02% OA, 4) Basel diet +0.02% OA. Growth performance was not significantly affected by all dietary treatments during the experiment period. Sensory evaluation of breast meat indicated a significant positive response for color and smell corresponding to treatment 2) Basal diet +0.1% HA and treatment 3) Basel diet +0.1% HA+ 0.02% OA (P < 0.05). Birds receiving HA and HAOA developed fewer hepatic lesions compared to the control group (P < 0.05) and showed normal spleen structure with the extension of the white pulp area. Supplementation of HAOA corresponds to a lower heterophil to lymphocyte (H/L) ratio. The combination of HA and OA improves sensory attributes of cooked breast meat, H/L ratio, and preserves the histological structure of the spleen and liver of broiler chickens. HAOA can be recommended as a combined feed additive to improve broiler chickens' health.

Blood leukocyte composition and function in periparturient ewes kept on different dietary magnesium supply.

BACKGROUND: Transition period (TP) is characterised by physiological and metabolic changes contributing to immunodysregulation. Since knowledge about this period in sheep is scarce, we analysed changes in selected immune variables during the TP in ewes and whether dietary magnesium (Mg) supplementation could modulate these immune variables. Pregnant ewes (2nd and 3rd lactation) were divided into a control group (CONT, n = 9) and a Mg group (MAG, n = 10) supplemented with Mg oxide resulting in a daily Mg intake of approximately 0.30 and 0.38% (MAG) of dry matter during ante- (a.p.) and post-partum (p.p.) periods, respectively. Blood samples were collected between days (d) 30 a.p. and d 30 p.p.. Whole blood neutrophil phagocytic activity, monocyte subset (classical cM, intermediate intM, non-classical ncM) composition and the proliferative capacity of lymphocytes were determined flow cytometrically. At d 14 a.p., all ewes were vaccinated against Mycobacterium avium subsp. paratuberculosis (MAP). RESULTS: Both groups showed a sharp increase in the total leukocyte counts (TLC) and neutrophil counts (P < 0.0001), at d 1 p.p., while, monocytes and their subpopulations displayed the highest values at d 30 p.p. (P ≤ 0.05). At d 1 p.p. the neutrophil phagocytic activity was higher (P < 0.05) in MAG ewes. Throughout the TP, the proliferative response of CD4+ cells was significantly higher in the MAG group (P < 0.05). Ewes in both groups responded with an increase in the TLC, neutrophil numbers (P ≤ 0.05) and ncM (P < 0.001) 24 h post vaccination, whereas monocytes and cM dropped in numbers (P ≤ 0.05). Numbers of intM only increased in MAG ewes (P < 0.05), whereas lymphocyte numbers decreased (P < 0.01). Mg supplementation did not affect the significant increase in MAP-specific antibodies at d 7 and 21 post vaccination. Total Mg and Ca serum levels did not show any differences between the two groups. CONCLUSION: Whereas TP-associated fluctuations in blood leukocyte numbers are not influenced by Mg supplementation, neutrophil phagocytic activity, the proliferative capacity of CD4+ cells and the cellular response within 24 h after a vaccination are subject to modulation.

Methyl donor supply to heat stress-challenged polymorphonuclear leukocytes from lactating Holstein cows enhances 1-carbon metabolism, immune response, and cytoprotective gene network abundance.

Mechanisms controlling immune function of dairy cows are dysregulated during heat stress (HS). Methyl donor supply-methionine (Met) and choline (Chol)-positively modulates innate immune function, particularly antioxidant systems of polymorphonuclear leukocytes (PMN). The objective of this study was to investigate the effect of Met and Chol supply in vitro on mRNA abundance of genes related to 1-carbon metabolism, inflammation, and immune function in short-term cultures of PMN isolated from mid-lactating Holstein cows in response to heat challenge. Blood PMN were isolated from 5 Holstein cows (153 ± 5 d postpartum, 34.63 ± 2.73 kg/d of milk production; mean ± SD). The PMN were incubated for 2 h at thermal-neutral (37°C; TN) or heat stress (42°C; HS) temperatures with 3 levels of Chol (0, 400, or 800 µg/mL) or 3 ratios of Lys:Met (Met; 3.6:1, 2.9:1, or 2.4:1). Supernatant concentrations of IL-1ß, IL-6, and tumor necrosis factor-α were measured via bovine-specific ELISA. Fold-changes in mRNA abundance were calculated separately for Chol and Met treatments to obtain the fold-change response at 42°C (HS) relative to 37°C (TN). Data were subjected to ANOVA using PROC MIXED in SAS (SAS Institute Inc., Cary, NC). Orthogonal contrasts were used to determine the linear or quadratic effect of Met and Chol for mRNA fold-change and supernatant cytokine concentrations. Compared with PMN receiving 0 µg of Chol/mL, heat-stressed PMN supplemented with Chol at 400 or 800 µg/mL had greater fold-change in abundance of CBS, CSAD, GSS, GSR, and GPX1. Among genes associated with inflammation and immune function, fold-change in abundance of TLR2, TLR4, IRAK1, IL1B, and IL10 increased with 400 and 800 µg of Chol/mL compared with PMN receiving 0 µg of Chol/mL. Fold-change in abundance of SAHH decreased linearly at increasing levels of Met supply. A linear effect was detected for MPO, NFKB1, and SOD1 due to greater fold-change in abundance when Met was increased to reach Lys:Met ratios of 2.9:1 and 2.4:1. Although increasing Chol supply upregulated BAX, BCL2, and HSP70, increased Met supply only upregulated BAX. Under HS conditions, enhancing PMN supply of Chol to 400 µg/mL effectively increased fold-change in abundance of genes involved in antioxidant production (conferring cellular processes protection from free radicals and reactive oxygen species), inflammatory signaling, and innate immunity. Although similar outcomes were obtained with Met supply at Lys:Met ratios of 2.9:1 and 2.4:1, the response was less pronounced. Both Chol and Met supply enhanced the cytoprotective characteristics of PMN through upregulation of heat shock proteins. Overall, the modulatory effects detected in the present experiment highlight an opportunity to use Met and particularly Chol supplementation during thermal stress.

Intrauterine therapy with ozone reduces subclinical endometritis and improves reproductive performance in postpartum dairy cows managed in pasture-based systems.

New postpartum strategies have been developed in dairy cows to ameliorate uterine health and reproductive performance, especially the first service conception rates. This study aimed to assess the effect of intrauterine therapy with ozone (IUTO) in early postpartum on subclinical endometritis prevalence and reproductive parameters in dairy cows under commercial farm conditions. For this purpose, eighty clinically healthy cows with a body condition score between 3.0 and 3.5, from four dairy farms, were randomly allocated into two groups: ozone therapy group (OG, n = 40), which were subjected to IUTO, and control group (CG, n = 40). Content of uterine polymorphonuclear (PMN) leukocytes and subclinical endometritis (SE) percentage were assessed at 35 days after calving by uterine cytology. A second cytology was performed 72 h after IUTO. Reproductive parameters such as interval calving to first service (IFS), number of services per conception (nSC), interval calving to conception (ICC) and first service conception rate (FSCR) were analysed. The second endometrial cytology demonstrated that IUTO reduced (P < 0.01) both PMN (3.7 ± 1.4 vs. 7.6 ± 1.1%) and SE (5.0 vs. 50.0%) percentages compared with CG. Likewise, after ozone treatment, both nSC (2.1 ± 0.3 vs. 3.1 ± 0.2; P < 0.01) and ICC (126.2 ± 9.7 vs. 149.0 ± 9.0; P = 0.0672) decreased, and FSCR increased (50.0 vs. 16.2%; P < 0.01) compared with CG. In conclusion, intrauterine ozone therapy applied at 35 days after calving reduced subclinical endometritis prevalence and improved reproductive performance in postpartum dairy cows managed in a pasture-based system.

HEMATOLOGY AND PLASMA CHEMISTRY VALUES IN BEACHED MAGELLANIC PENGUIN (SPHENISCUS MAGELLANICUS) IN NORTHERN ARGENTINA DURING THE NONBREEDING SEASON.

Seabirds have been widely used for monitoring the health of the oceans in diverse marine regions. Among low-cost survey strategies, systematic surveys of seabirds beached on coasts have been developed since the 20th century. However, these studies do not always address blood aspects. The assessment of the health status of birds based on the analysis of hematological and plasma chemistry is crucial to evaluate the overall health status profile of live organisms. Here, the authors study the variability of blood parameters by sex, age class, and year of beached Magellanic Penguin during the nonreproductive period in northern Argentina. Of 44 penguins, 77% were categorized as younger juveniles and the rest as older juveniles, and were captured and studied in coastal areas of Buenos Aires Province during the summers of 2017 and 2018. The mean body weight of beached penguins was affected by the age class of the individuals; most of the younger juveniles showed poor condition in terms of body mass (1,761 ± 235 g). No significant differences were observed in body weight between years and sex. Still, there were significant differences between years for alkaline phosphatase (ALP) and creatine phosphokinase (CPK) values. Twelve of the 20 blood parameters analyzed differ significantly with the age class of the beached penguins; younger juveniles were in a state of inanition. Our results may serve as a necessary first step in improving the conservation status of the Magellanic Penguin in nonbreeding grounds of Argentina, and call for a better knowledge of the health status of the species along its annual cycle.

Performance, biochemical and haematological responses, and relative organ weights of laying hens fed diets supplemented with prebiotic, probiotic and synbiotic.

BACKGROUND: The increasing trend of ban on the use of antibiotic growth promoters (AGPs) across the globe in the poultry industry has led to a growing need for alternatives to AGPs. Prebiotic, probiotic and their combination as a synbiotic have been considered as potential alternatives. This study aimed to investigate the effects of a prebiotic (isomaltooligosaccharide, IMO), a probiotic (PrimaLac®), and their combination (synbiotic) on hen performance, biochemical and haematological responses, and relative organ weights from 20 to 52 weeks of age. RESULTS: Supplementation of 1% IMO (PRE), 0.1% PrimaLac® (PRO) and 1% IMO + 0.1% PrimaLac® (SYN) improved (P < 0.05) feed intake and egg production at 20-36 weeks of age; body weight gain, feed conversion ratio and egg mass at 20-36 and 20-52 weeks of age; and egg weight at 20-36, 37-52 and 20-52 weeks of age. Compared to control-fed hens at 20-36 weeks of age, PRO- and SYN-fed hens produced less (P < 0.05) small size eggs while SYN-fed hens produced more large size eggs. From 37 to 52 weeks of age, PRE-, PRO- or SYN-fed hens produced less (P < 0.05) medium size eggs, and more large and extra-large size eggs. PRE, PRO or SYN supplementation decreased (P < 0.05) the serum total cholesterol at 36 weeks of age, and serum low-density lipoprotein (LDL) cholesterol, alanine aminotransferase (ALT) and alkaline phosphatase (ALP) at 36 and 52 weeks of age. At 36 and 52 weeks of age, supplementation of PRE, PRO or SYN increased (P < 0.05) lymphocyte percentage and decreased (P < 0.05) heterophil percentage, leading to a lower heterophil to lymphocyte (H/L) ratio. No significant differences were observed in the relative weights of the heart, liver, ovary, pancreas and spleen of all dietary treatment groups. CONCLUSIONS: Supplementation of PRE, PRO or SYN improved performance, serum total cholesterol, LDL cholesterol, ALT, ALP and H/L ratio of hens from 20 to 52 weeks of age. These results demonstrated the use of PRE, PRO and SYN as alternative feed additives to AGPs for improving the health and productivity of hens, while PRO is the best for commercial layer production to yield maximum profit.

Diferentes fontes de ferro na prevenção da anemia ferropriva e no desempenho de leitões lactentes / Different sources of iron for the prevention of iron deficiency anemia and performance of suckling piglets

Com o objetivo de avaliar o uso de diferentes fontes de ferro na prevenção da anemia ferropriva e no desempenho em leitões lactentes, dividiram-se 202 leitões em cinco tratamentos: FD - aplicação intramuscular de 200mg de ferro dextrano no terceiro dia de idade; T24 - terra à vontade fornecida aos leitões a cada 24 horas do terceiro ao 19º dia; T48 - terra à vontade fornecida aos leitões a cada 24 horas do terceiro ao 10º dia e do 11º ao 19º dia, com intervalo de 48 horas; T72 - terra à vontade fornecida aos leitões a cada 24 horas do terceiro ao 10º dia e do 11º ao 19º dia, com intervalo de 72 horas; SA - suplemento alimentar ultraprecoce rico em ferro quelatado em pó (SAUP) fornecido do terceiro ao 11º dia, com intervalo de 48 horas. O ferro dextrano aplicado no terceiro dia de vida e a suplementação com terra e SAUP foram eficientes para garantir o desempenho de leitões no período de aleitamento e não influenciaram no consumo de ração nem na taxa de viabilidade. As diferentes fontes de ferro estudadas não influenciaram o leucograma e foram eficientes na prevenção da anemia ferropriva e no desempenho dos leitões lactentes. Com relação às concentrações de hemoglobina e hematócrito, os animais suplementados com ferro dextrano apresentaram valores superiores quando comparados aos que recebem terra e SAUP.(AU)

In order to evaluate the use of different sources of iron to prevent iron deficiency anemia and to appraise the performance of suckling piglets, we sorted 202 piglets in five treatments. ID - intramuscular injection of 200mg of iron dextran on the third day of age; T24 - free daily access to land provided to piglets every 24 hours from the third to the nineteenth day; T48 - free daily access to land provided to piglets every 24 hours from the third to the tenth day and from day 11 to day 19 with an interval of 48 hours; T72 - free daily access to land provided to piglets every 24 hours from the third to the tenth day and from day 11 to day 19 with an interval of 72 hours; FS - Food supplement rich in iron-chelating powder (SAUP) available from the third to the eleventh day with an interval of 48 hours. The iron dextran applied on the third day of life as well as the supplementation with land and SAUP were effective to ensure the performance of piglets during the lactation period and did not affect feed intake or the viability rate. The different sources of iron studied did not influence the WBC (White Blood Cell) and succeded in preventing iron deficiency anemia and performance of suckling piglets. Regarding the concentrations of hemoglobin and hematocrit, the animals supplemented with iron dextran showed higher values when compared to those who receive land and SAUP.(AU)

Alleviation of chronic heat stress in broilers by dietary supplementation of betaine and turmeric rhizome powder: dynamics of performance, leukocyte profile, humoral immunity, and antioxidant status.

Heat stress (HS), one of the most serious climate problems of tropical and subtropical countries, negatively affects the production performance of broilers. Keeping this in view, the current study was aimed at elucidating the effects of supplementing betaine (Bet) and dried turmeric rhizome powder (TRP), either singly or in combination, on growth performance, leukocyte profile, humoral immunity, and antioxidant status in broilers kept under chronic HS. A total of 625 one-day-old Ross male chicks were randomly assigned to five treatment groups (5 replicates of 25 birds per replicate pen). From day 1, the birds were either kept at the thermoneutral zone (TN) or exposed to HS (33 ± 1°C) to the conclusion of study, day 42. THeat stress (HS), one of the most serious climate problems of tropical and subtropical countries, negatively affects the production performance of broilers. Keeping this in view, the current study was aimed at elucidating the effects of supplementing betaine (Bet) and dried turmeric rhizome powder (TRP), either singly or in combination, on growth performance, leukocyte profile, humoral immunity, and antioxidant status in broilers kept under chronic HS. A total of 625 one-day-old Ross male chicks were randomly assigned to five treatment groups (5 replicates of 25 birds per replicate pen). From day 1, the birds were either kept at the thermoneutral zone (TN) or exposed to HS (33 ± 1°C) to the conclusion of study, day 42. The treatment groups were as follows: thermoneutral control (TN-CON), HS-CON, HS-Bet, HS-TRP, and HS-BT (fed Bet and TRP). The results showed that decreases in body weight gain, feed intake, and increases in feed-to-gain ratio and mortality induced by HS were partially restored by dietary supplementation of Bet and TRP. The heterophil/lymphocyte ratio, total, and IgG antibody titers against sheep red blood cell for secondary responses in the HS-TRP and HS-BT groups were also similar to those of the broilers in the TN-CON group but better (P < 0.05) than for HS-CON group. An increase (P < 0.05) in serum concentration of malondialdehyde induced by HS was significantly decreased by dietary supplementations. The serum glutathione peroxidase and superoxide dismutase activities were also higher (P < 0.05) in the supplemented groups compared to both TN and HS-CON groups. In conclusion, dietary supplementation of either Bet or TRP alone or in combination can partially ameliorate some of the detrimental effects of HS in broilers. Results also suggest that TRP might be better than Bet for improving stress tolerance and immune response in heat-stressed broilers.he treatment groups were as follows: thermoneutral control (TN-CON), HS-CON, HS-Bet, HS-TRP, and HS-BT (fed Bet and TRP). The results showed that decreases in body weight gain, feed intake, and increases in feed-to-gain ratio and mortality induced by HS were partially restored by dietary supplementation of Bet and TRP. The heterophil/lymphocyte ratio, total, and IgG antibody titers against sheep red blood cell for secondary responses in the HS-TRP and HS-BT groups were also similar to those of the broilers in the TN-CON group but better (P < 0.05) than for HS-CON group. An increase (P < 0.05) in serum concentration of malondialdehyde induced by HS was significantly decreased by dietary supplementations. The serum glutathione peroxidase and superoxide dismutase activities were also higher (P < 0.05) in the supplemented groups compared to both TN and HS-CON groups. In conclusion, dietary supplementation of either Bet or TRP alone or in combination can partially ameliorate some of the detrimental effects of HS in broilers. Results also suggest that TRP might be better than Bet for improving stress tolerance and immune response in heat-stressed broilers.

Acute brief heat stress in late gestation alters neonatal calf innate immune functions.

Heat stress, as one of the environmental stressors affecting the dairy industry, compromises the cow milk production, immune function, and reproductive system. However, few studies have looked at how prenatal heat stress (HS) affects the offspring. The objective of this study was to evaluate the effect of HS during late gestation on calf immunity. Calves were born to cows exposed to evaporative cooling (CT) or HS (cyclic 23-35°C) for 1 wk at 3 wk before calving. Both bull and heifer calves (CT, n=10; HS, n=10) were housed in similar environmental temperatures after birth. Both CT and HS calves received 3.78 L of pooled colostrum within 12 h after birth and were fed the same diet throughout the study. In addition to tumor necrosis factor α, IL-1ß, IL-1 receptor antagonist (IL-1RA), and toll-like receptor (TLR)2, and TLR4 mRNA expression, the expression of CD14(+) and CD18(+) cells, and DEC205(+) dendritic cells were determined in whole blood samples at d 0, 3, 7, 14, 21, and 28. The neutrophil to lymphocyte ratio, differential cell counts, and the hematocrit were also determined. During late gestation, the HS cows had greater respiration rates, rectal temperatures, and tended to spend more time standing compared with the CT cows. The HS calves had less expression of tumor necrosis factor-α and TLR2 and greater levels of IL-1ß, IL-1RA, and TLR4 compared with CT calves. The HS calves also had a greater percentage of CD18(+) cells compared with the CT calves. Additionally, a greater percentage of neutrophils and lesser percentage of lymphocytes were in the HS calves compared with the CT calves. The results indicate that biomarkers of calves' immunity are affected in the first several weeks after birth by HS in the dam during late gestation.

Effect of dexamethasone in feed on intestinal permeability, differential white blood cell counts, and immune organs in broiler chicks.

We have previously shown that intestinal barrier function can be adversely affected by poorly digested diets or feed restriction, resulting in increased intestinal inflammation-associated permeability. Three experiments were conducted in broilers to evaluate the effect of dexamethasone (DEX) treatment on systemic fluorescein isothiocyanate-dextran (FITC-D; 3-5 kDa) levels, indicative of increased gut epithelial leakage. Experiment 1 compared DEX injections of 1 mg/kg, once per day on d 3, 5, and 9, with feed administration at 0.57, 1.7, or 5.1 ppm d 4 to 10, with FITC-D serum concentrations 2.5 h after gavage with 4.16 mg/kg FITC-D. All DEX treatments resulted in marked (2 to 6X; P<0.05) increased serum FITC-D levels. Feed DEX administration resulted in greater (P<0.05) gut permeability than injection at any dose, with numerically optimal effects at the lowest dose tested. In experiments 2 and 3, chicks were randomly assigned to a starter ration containing either control (CON) or DEX treated feed (0.57 ppm/kg; d 3 to 10 experiment 2, d 4 to 10 experiment 3). At d 10, all chicks were treated by oral gavage with FITC-D and serum samples were obtained as described above. Samples of the liver were aseptically collected, homogenized, diluted 1:4 wt/vol in sterile saline, and serial dilutions were plated on tryptic soy agar to evaluate total numbers of aerobic bacteria in the liver as an index of bacterial translocation (BT). In both experiments, FITC-D absorption was significantly enhanced (P<0.05) in DEX-treated chicks, again indicating increased paracellular leakage across the gut epithelium associated with dissolution of tight junctions. Experiment 2 differential cell counts showed an increased heterophil/lymphocyte ratio, and immune organ (spleen and bursa of Fabricius) weights for experiments 2 and 3 were decreased (P<0.05) from controls. In experiments 2 and 3, dietary DEX administration resulted in numerically (experiment 2) or significantly (P<0.05) increased enteric BT to the liver, supporting the observation that dietary DEX causes a stress-like inflammatory GI response, which may contribute to subclinical or clinical disease, and may be a useful model for ongoing disease mitigation research related to stress-related diseases of GIT origin.

Effect of supplemental vitamin E on the peripheral blood leukocyte population in Japanese Black calves.

We investigated the effect of supplemental vitamin E on the peripheral blood leukocyte population in Japanese Black calves. Twenty-six calves kept at the same farm were studied. They were divided into two groups; thirteen calves received 300 IU/day of vitamin E orally from 1 to 3 months of age (VE group), and the other thirteen calves did not receive the vitamin E supplement (control group). The VE group showed a higher serum vitamin E concentration at 2 and 3 months of age compared with the control group (P<0.01). The numbers of CD3(+) cells and CD4(+) cells were higher in the VE group than in the control group, and the difference was statistically significant at 3 months of age (P<0.05). The numbers of CD21(+) cells were higher in the VE group than in the control group, and the difference was statistically significant at 2 months of age (P<0.05). The numbers of CD335(+) cells tended to be higher in the VE group than in the control group. The numbers of CD8(+) cells and CD14(+) cells tended to be higher in the VE group than in the control group at 3 and 4 months of age. This study demonstrated that the supplementation of suckling Japanese Black calves with vitamin E might affect the numbers of some immune cell types in the peripheral blood.

Dietary L-arginine modulates immunosuppression in broilers inoculated with an intermediate strain of infectious bursa disease virus.

BACKGROUND: The effects of dietary l-arginine (Arg) on immunosuppression following infectious bursal disease virus (IBDV) inoculation in broiler chickens were evaluated. The design of this study was a 5 × 2 factorial arrangement (n = 5) with five Arg concentrations (starter: 9.9, 13.9, 17.6, 21.3 and 25.3 g kg(-1) ; grower-finisher: 9.5, 13.5, 17.1, 20.1 and 23.6 g kg(-1) ) with or without IBDV inoculation (IBDV or saline inoculation at 14 days). Chickens were sampled at 2, 4 and 6 days post-inoculation (DPI) and 42 days of age. RESULTS: The IBDV inoculation decreased (P = 0.05) CD3(+) , CD4(+) , and CD8(+) T cell counts at 2 days post-inoculation (DPI) and monocyte counts at 6 DPI; and reduced (P < 0.05) bursal interleukin-1ß (IL-1ß) mRNA expression at 2 DPI and serum IL-6 concentration at 4 DPI. Increasing Arg concentration increased (P < 0.05) CD4(+) and CD8(+) T cell counts at 2 DPI, linearly increased (P = 0.05) CD3(+) T cell counts in IBDV-inoculated groups and monocyte counts in control groups at 4 DPI; increased (P < 0.05) serum IL-6 concentration in IBDV-inoculated groups at 2 DPI; and increased (P < 0.05) serum anti-IBDV antibody titres at 42 days of age. CONCLUSION: Varying concentrations of Arg supplementation attenuated IBDV inoculation induced immunosuppression via modulating circulating T cell sub-populations.

Dietary fucoidan enhance the non-specific immune response and disease resistance in African catfish, Clarias gariepinus, immunosuppressed by cadmium chloride.

Fucoidan is sulfated polysaccharide extracted from seaweed brown algae. This study was designed to evaluate the immunomodulatory effects and disease resistance of dietary fucoidan on catfish, Clarias gariepinus, immunosuppressed by cadmium. Three hundred and sixty African catfish, C. gariepinus, was allocated into six equal groups. The first group served as a control. Groups (F1 and F2) were fed on fucoidan supplemented ration at concentrations of 4 and 6g/kg diet respectively for 21 days. Groups (Cd, CdF1 and CdF2) were subjected throughout the experiment to a sub-lethal concentration of 5ppm cadmium chloride solution and groups (CdF1 and CdF2) were fed on a ration supplemented with fucoidan. Macrophages oxidative burst, phagocytic activity percentages and lymphocytes transformation index were a significant increase in the fucoidan-treated groups (F1 and F2), while serum lysozyme, nitric oxide and bactericidal activity were enhanced only in group (F2) when compared with controls. These parameters as well as absolute lymphocyte count and survival rate were significantly increased in group (CdF2) when compared with cadmium chloride immunosuppressed group (Cd). It could be concluded that the fucoidan can be used as immunostimulant for the farmed African catfish, C. gariepinus as it can improve its resistance to immunosuppressive stressful conditions.

Influence of feeding a low-phosphorus diet on leucocyte function in dairy cows.

Phosphorus depletion and hypophosphatemia have been described to interfere with immune function in rats and humans. In dairy cows, hypophosphatemia has been associated with muscle weakness and recumbency as well as with intravascular hemolysis resulting from increased osmotic fragility of erythrocytes, but so far, the influence of P depletion and hypophosphatemia on immune function has not been studied. Therefore, the aim of this study was to investigate whether P depletion and ensuing hypophosphatemia are associated with impaired granulocyte and lymphocyte function. Eight mid-lactation dairy cows were fed a P-deficient ration (0.2% P/kg of DM) for a period of 4wk. The depletion phase was preceded by a 2-wk acclimatization period and followed by a 2-wk repletion phase, during which the same ration was supplemented with P to meet or exceed daily requirements. Blood samples were collected at the end of the acclimatization period, after 2 and 4wk of P depletion, and at the end of the repletion phase. Plasma phosphate concentrations ([Pi]) were determined and white blood cells were counted and isolated. General immune function was investigated by performing a phagocytosis assay with Staphylococcus aureus and a lymphocyte stimulation test (LST) with concanavalin A and pokeweed mitogen. The plasma [Pi] decreased significantly, with the lowest values (mean 0.7±0.2mmol/L) occurring after 2wk of depletion, although depletion was continued for another 2wk. During repletion, plasma [Pi] increased above baseline concentrations. Granulocyte counts changed in parallel with plasma [Pi] over time, decreasing significantly at 2wk after P depletion and increasing again thereafter. Granulocyte survival after phagocytosis was lowest after 4wk of P depletion. Phagocytosis activity of surviving granulocytes determined by mean fluorescence intensity was higher, indicating that phagocytosis was not negatively influenced by P depletion. Lymphocyte stimulation showed a similar trend, with a decreasing stimulation index at the end of P depletion, but differences were not statistically significant. Data presented in this study indicate that hypophosphatemia leads to a decrease in granulocyte counts. Chronic P depletion impairs granulocyte survival during phagocytosis but not phagocytosis activity. Lymphocyte function is not influenced by P depletion.

Effects of dietary selenium on the pathological changes and oxidative stress in loach (Paramisgurnus dabryanus).

In this study, loach (Paramisgurnus dabryanus) were fed artificial diets containing 0.31 (control), 0.39, 0.48, 0.50 and 0.62 mg kg(-1) of selenium (Se) for 60 days, respectively. Liver histopathology, hepatocyte ultrastructure, blood indices, biochemical parameters of liver functions and oxidative stress in the Se-treated loach were then assayed. The results showed the following: histopathological and ultrastructural lesions in liver were only observed in loach fed the 0.62 mg Se kg(-1) diet; Haemoglobin and total protein were significantly increased in the 0.50 mg Se kg(-1) group; albumin and high-density lipoprotein were increased significantly in the 0.48-0.50 mg Se kg(-1) groups. However, white blood cell count was significantly decreased in the 0.48 mg Se kg(-1) group; alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase were decreased in the 0.39-0.50 mg Se kg(-1) groups. In liver tissue, the content of hydrogen peroxide was lower than that of controls in the 0.48-0.50 mg Se kg(-1) groups, and the malondialdehyde level was lowest in the 0.48 mg Se kg(-1) group. The activities of superoxide dismutase and glutathione peroxidase were significantly increased in the 0.50 mg Se kg(-1) group; catalase and total antioxidant capacity were markedly increased in the 0.48-0.50 mg Se kg(-1) group. These present results indicated that the dietary Se requirement for loach is 0.48-0.50 mg Se kg(-1) diet.

Effect of ellagic acid on some haematological, immunological and antioxidant parameters of rainbow trout (Oncorhynchus mykiss).

In this study, effect of ellagic acid on some haematological, immunological and antioxidant parameters in the blood and various tissues of rainbow trout (Oncorhynchus mykiss) were examined. Four groups of rainbow trout were fed experimental diets containing either no ellagic acid (control) or supplemented with ellagic acid at 50 mg/kg diet (EA-50), 100 mg/kg diet (EA-100) or 150 mg/kg diet (EA-150) for 21 days. Samples of the blood and tissue (liver, kidney and spleen) were collected at the end of the experiment and analysed for their haematological profile (the red blood cell count, the haemoglobin concentration and the haematocrit level), immune response (the white blood cell count, the oxidative radical production (NBT activity), the total plasma protein and total immunoglobulin level) and oxidant/antioxidant status (the malondialdehyde level, the superoxide dismutase, catalase and glutathione peroxidase activity as well as the reduced glutathione concentration). The findings of this study demonstrated that ellagic acid had a positive effect on the haematological parameters, the immune response and the antioxidant enzyme activities of the fish.

Mycobacteriosis in a domestic ferret (Mustela putorius furo).

A 4-year-old spayed female ferret presented with a 2-month history of anorexia, vomiting and occasional diarrhea. Abdominal ultrasonography revealed thickening of the gastric wall and enlarged abdominal lymph nodes. Biopsy samples from the thickened gastric wall, enlarged abdominal lymph nodes and liver were taken during an exploratory laparotomy. Based on the histopathological examination, mycobacterium infection was diagnosed. The bacterial species could not be identified by additional diagnostic tests of feces, including fecal smear, culture and polymerase chain reaction (PCR). The ferret was treated with prednisolone and multiple antimicrobials, including rifampicin, azithromycin and enrofloxacin, but did not improve with treatment and died 220 days after the first presentation.

Effect of transportation on fecal bacterial communities and fermentative activities in horses: impact of Saccharomyces cerevisiae CNCM I-1077 supplementation.

This study evaluated the effect of transportation on fecal bacterial communities and activities in horses with or without supplementation of live yeast and attempted to link those effects with changes in blood stress markers. Four mature horses were assigned to a crossover design and fed a basal diet (60:40 forage to concentrate; 1.45% BW on a DM basis), with or without supplementation, of 2 × 10(10) cfu/d of Saccharomyces cerevisiae CNCM I-1077. After a 14-d adaptation to dietary treatments, the 5-d experiment started 1 d before transportation (d -1). At d 0, horses were simultaneously transported in a truck for 2 h. Feces were sampled 4 h after the morning meal of concentrate at d -1, 0 (immediately after transportation), and 3 for enumeration of the main functional bacterial groups and determination of fermentative variables. Within each dietary treatment, feces were pooled before DNA extraction and molecular analysis of the bacterial communities, using temporal temperature gradient electrophoreses (TTGE). Blood samples were collected at the same time for determination of white blood cells (WBC) counts and glucose and total protein concentrations. Regardless of dietary treatment, the neutrophil to lymphocyte ratio increased during transportation (P < 0.01), indicating that horses were stressed. In both treatments, TTGE profiles were clearly different before and 3 d after transportation, and the percentage of similarity between profiles at d -1 and 3 was greater in supplemented horses compared with the controls. From d 0 to 3, the molar percentage of propionate increased and total concentration of VFA and the acetate + butyrate to propionate ratio decreased, regardless of dietary treatment (P < 0.01, P = 0.02, and P < 0.01, respectively), whereas pH decreased only in control horses (P = 0.03). Regardless of day of sampling, fecal concentrations of lactate-utilizing bacteria and cellulolytic bacteria were greater in supplemented horses than in control horses (P = 0.04 and 0.08, respectively). Our results indicate that transportation for 2 h disturbed the fecal bacterial ecosystem in horses that could increase the risk of triggering microbial dysbiosis on a longer term in the equine large intestine. Supplementing Saccharomyces cerevisiae CNCM I-1077 could help reduce the negative impact of transportation on the fecal bacterial ecosystem.

Effect of pre-partum supplementation of vitamin E to Murrah buffaloes on immune functions and viability of calves.

This study was undertaken in buffalo neonates born to vitamin E (dl-alpha-tocopherol acetate)-supplemented and non-supplemented Murrah buffaloes. Calves from vitamin E-supplemented buffaloes (n = 10; vitamin E -supplemented calves [VeC]) and non-supplemented buffaloes (n = 10; control calves [CC]) constituted the treatment and control groups respectively. Two colostrum samples were taken at the first post-partum milking and again after 12 h from dams for IgG estimation. Sampling of blood was performed on days 0 (before colostrum feeding), 1, 3, 7, 14, 21, 28, 42, 56, 70, 84, 98, 112 and 126 post-birth and analysed for apparent efficiency of absorption (%) of IgG and various immune parameters. Colostral IgG level was significantly higher (p < 0.05) in vitamin E-supplemented buffaloes. The calves in both groups were born hypogammaglobulinemic with IgG level <5 g/l. However, first colostrum feeding resulted in significantly elevated IgG levels (>10 g/l) in calves of both groups at 24 h, which remained high afterwards. Apparent efficiency of absorption (%) of IgG at 24 h was significantly higher (p < 0.05) in VeC than in CC. Plasma Nitric Oxide (NO) levels were significantly elevated in the calves of either group at birth, which declined significantly (p < 0.01) afterwards. Vitamin E feeding to dams had no added effect on NO levels in experimental calves. Total leucocyte counts did not differ significantly between the two groups. However, lymphocyte and neutrophil counts changed significantly between groups (p < 0.01) and days (p < 0.01), with lymphocytes increasing and neutrophils declining with age. This study revealed that the calves were immunologically immature at birth. Ante-partum supplementation of vitamin E did not influence plasma NO or IgG but had a significant effect on colostral IgG (p < 0.05). It also improved the apparent efficiency of absorption (%) of IgG at 24 h in VeC as compared to CC.

Dietary administration of chitooligosaccharides to enhance growth, innate immune response and disease resistance of Trachinotus ovatus.

The present study was conducted to investigate the effects of dietary chitooligosaccharides (COS) supplementation on the innate immune response and protection against Vibrio harveyi infection in Trachinotus ovatus. A basal diet was supplemented with 0.0 (control), 2.0, 4.0 and 6.0 g COS kg(-1) to formulate four experimental diets. Each diet was randomly allocated to triplicate groups of fish in floating sea cages (1.5 × 1.0 × 2.0 m), and each cage was stocked with 80 fish (initial average weight 10.8 ± 0.05 g). After 8 weeks of feeding trial, Both the final weight and specific growth rate (SGR) significantly increased with increasing dietary COS levels up to 4.0 g kg(-1), whereas there were no significant differences for COS levels from 4.0 to 6.0 g kg(-1). A decreased feed conversion ratio (FCR) was observed with increasing dietary COS levels. The total leukocyte counts (WBC), differential leukocyte counts, respiratory burst activity, lysozyme and superoxide dismutase (SOD) activity were significantly increased with the increased levels of dietary COS (P < 0.05), and reached a maximum at level of 4.0 g kg(-1) COS. There were no significant differences in those immunological parameters between 4.0 and 6.0 g kg(-1) COS. Moreover, the dietary COS supplementation groups also exhibited a decrease in the cumulative symptom rates compared to the controls when challenged with V. harveyi. These results indicated that dietary intake containing COS could enhance the immune responses of fish and improve its resistance to infection by V. harveyi. Especially supplementation with 4.0 g kg(-1) COS to the fish for 56 days showed considerable improvement in the growth, survival and immune response of the fish.