Gabriela Campigotto

Fowl typhoid in laying hens cause hepatic oxidative stress

The aim of this study was to analyses nitric oxide, antioxidant status, and oxidative profile in the liver of laying hens naturally infected by Salmonella enterica subsp enterica serovar Gallinarum (S. Gallinarum). The nitrite/nitrate (NOx), reactive oxygen species (ROS), thiobarbituric acid-reactive substances (TBARS), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx) and glutathione S-transferase (GST) activities were measured in liver samples, as well the biomarkers of hepatic function (alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyltransferase (GGT), total protein and albumin levels measured in serum. NOx levels and CAT activity were reduced in hepatic tissue of infected hens. On the other hand, TBARS and ROS levels, GR, GPx and GST activities were higher in infected animals. On biomarkers of tissue damage, ALT, AST, GGT and total protein levels were higher in serum of infected hens, and showed decreased albumin levels. In summary, ROS and TBARS production lead to damage on the membrane lipids that alter activities of antioxidant enzymes CAT, GR, GPx and GSH, an adaptive response against S. Gallinarum infection, contributing to the pathophysiology and clinical signs of the disease.

Biochemical variable levels of newborn lambs under extensive rearing system

The aim of this study was to evaluate the biochemical variables in newborn lambs of an extensive rearing system. In this study, 30 multiparous ewes, with simple parturition, and their 30 lambs were used. Blood samples were drawn from the ewes (on days 1, 5, and 10 postpartum) and lambs (before ingestion of colostrum, and on days 1, 5, and 10 postpartum), in order to measure the serum variables related to lipid and protein metabolism (total protein, albumin, globulin, urea, triglycerides, and cholesterol). Ewe’s blood levels of total protein, albumin, globulin, and urea did not differ throughout the evaluated periods (P > 0.05). However, on day 1 postpartum, the levels of triglyceride were higher than on day 10, while the cholesterol levels decreased progressively, following the evaluation periods (P < 0.05). In lamb’s samples, the levels of total proteins, albumin and globulin were higher on day 10, when compared with the other periods (P < 0.05). Unlike, serum levels of urea, triglycerides and cholesterol were higher on the first day of life, when compared with the levels before the ingestion of colostrum and with the fifth and tenth days (P < 0.05). Therefore, our results allowed to conclude that on the first day of life (for lambs) and in postpartum (for ewes), there occurred a fluctuations of biochemical variables, mainly related to lipid and protein metabolism. These variations may be related to the ingestion of colostrum and/or milk in lambs, and hormonal changes in ewes.

Experimental infection by Trypanosoma evansi in sheep: Occurrence of transplacental transmission and mice infection by parasite present in the colostrum and milk of infected ewes.

The aims of this study were to evaluate vertical transmission of Trypanosoma evansi in sheep experimentally infected, in addition to the mammary transmission by colostrum or milk of these infected sheep to mice. Three pregnant sheep were used: one uninfected, four months pregnant (Sheep A); and two (Sheep B and C) infected intravenously by T. evansi trypomastigotes (4.6×10(6) per animal) on the third (Sheep C) and fourth (Sheep B) month of pregnancy. Both infected sheep developed low and oscillating parasitemia measured by blood smears. Hemogram was performed at seven day intervals, showing anemia, leukocytosis, and lymphocytosis on sheep B and C. Three sheep had twins, where sheep A delivered healthy lambs and both infected sheep had delivered at least one stillborn. Additionally, lambs from sheep B and C died 24 and 72 h post-partum, respectively. Before colostrum intake, four lambs from infected sheep were positives for T. evansi according to blood smear evaluation, serology (CATT/T. evansi), and PCR. Sheep colostrum and milk samples collected from the first four days post-partum were positives for T. evansi on PCR, and these samples were able to infect seven mice (out of 10) orally (n=4/5) and intraperitoneally (n=3/5). Therefore, we conclude that the vertical transmission of T. evansi occurs in pregnant sheep, in addition to a strong possibility of the transmission by colostrum and milk.

Mineralization in newborn calves contributes to health, improve the antioxidant system and reduces bacterial infections

The first phase of life of dairy calves has elevated mortality indices linked with low immunity and sanitary challenges, mainly bacterial infections are involved in the pathogenesis of diarrhea, the leading cause of death. Also, other important problem is the nutritional deficiencies, such as the mineral deficiency. Thus, the aim of this study was to evaluate whether an intramuscular mineral supplementation based on selenium, copper, potassium, magnesium and phosphorus possess beneficial effects on health of dairy calves. For this, ten calves were divided in two groups: the group A was supplemented with injectable mineral, while the group B was used as control group (without mineral supplementation). The mineral complex was administrated via intramuscularly at dose of 3 mL/animal on days 2 and 14 post-birth. The total blood was collected on days 2, 10, 20 and 30 of life of animals in order to analyze the antioxidant enzymes (catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx)), blood count and seric biochemistry linked with proteic, lipid and carbohydrate metabolism. Feces samples were also collected on days 10, 20 and 30 of life of animals to perform the total bacterial count, parasitological exam and fecal consistency score. Moreover, the weight and corporal temperature were also evaluated. The mineral supplementation presented beneficial properties to calves from birth to the 30th of life through the increase on activity of antioxidant enzymes, improvement of immunity, and avoiding problems linked with diarrhea and anemia, can be considered an interesting approach to prevent these alterations linked with high mortality in the period of life.

Effects of phytogenic feed additive based on thymol, carvacrol and cinnamic aldehyde on body weight, blood parameters and environmental bacteria in broilers chickens

The aim of this study was to evaluate whether a phytogenic feed additive (PFA) based on essential oils such as carvacrol, thymol and cinnamic aldehyde, could be considered a replacement for antimicrobials used as growth promoters in broiler chickens, as well as to investigate its effect on total bacterial count, biochemical profiles, meat quality and meat fatty acid profile. A total of 240 broiler chicks were randomly distributed into 4 groups with 4 replicates of 15 animals each, as follow: T1 (basal diet only; the control group), T2 (basal diet supplemented with zinc bacitracin), T3 (basal diet with 0.5% of the PFA), T4 (basal diet with 1.0% of the PFA). The addition of 0.5% of the PFA improved live body weight of supplemented birds compared to the control group at 35 and 42 days of age, while the total bacterial count in the environment was reduced when 1.0% of the PFA was used. In addition, intestinal villi height and crypt depth suffered variations during the entire experiment in birds treated with both concentrations of the PFA and zinc bacitracin. Total erythrocyte counts were higher on days 14, 28 and 42 in both treated groups (PFA) compared to the control group, as well as hemoglobin content on days 28 and 42. On the other hand, leukocyte counts were lower on days 14, 28 and 42 due to reduced lymphocyte counts in both PFA treated groups compared to the control group. Serum levels of alanine aminotransferase (ALT) were lower in broilers fed with either concentration of PFA on day 14 of life, and the same was observed regarding aspartate aminotransferase (AST) in broiler treated with 0.5% of the PFA. Also, total protein and globulin levels were lower on days 14 and 28 in groups fed with phytogenic compared to the control group. Regarding meat quality, breast meat showed higher red intensity and shear force in groups fed with both concentrations of phytogenic compared to the control group, while weight loss by cooking was lower. Finally, 1.0% of phytogenic showed lower docosadienoic acid (C22:2) content in breast meat. In conclusion, results showed that the use of PFAs based on carvacrol and thymol may be considered an interesting alternative to increase broilers performance, replacing the use of antimicrobials as growth promoters, as well as an interesting alternative to reduce the total bacterial count in the environment of broiler chickens. Moreover, the diet containing phytogenic also showed hepaprotective effects but deserves attention regarding possible alterations on the immune response.

Risk factors for Toxoplasma gondii in sheep of southern Brazil

Toxoplasma gondii is responsible for reproductive failure in sheep, and it is considered a zoonotic parasite. Therefore, the aim of this study was to evaluate the prevalence of toxoplasmosis and its risk factors at the farm level. For that, 314 sheep from 18 farms of 7 municipalities of the West part of Santa Catarina State, Southern Brazil were used. To identify possible risk factors associated to the disease, a survey was applied to farmers with questions regarding farm characteristics, type of management, and history of animal reproductive problems. Out of 314 sera samples, 118 (37%, CI 95% 32.3–43.3) were positives for T. gondii. Multivariate analyses showed that allowing cats to have access to sheep feed was significantly associated to toxoplasmosis, with an odds ratio of 2.42. Similarly, keeping cats in the farm increased 1.67 times the chances of T. gondii infection by sheep. Therefore, we concluded that sheep infection by T. gondii in the West of Santa Catarina state is distributed very similarly to other regions of Brazil, and the presence of cats in the property is strongly correlated to the occurrence of the disease.