Addition of açai oil during the close-up dry period of Holstein cows improves colostrum quality and immune responses of their calves.

This study evaluated of the effects of açai oil during the close-up dry period of Holstein cows on colostrum quality, as well as on the immune and antioxidant responses of their calves. Sixteen multiparous cows were assigned randomly to two treatments: 1) CONTROL (n = 8) - 4.48% of soybean oil/concentrate; 2) AÇAI (n =8) - 4.48% of açai oil/concentrate. Cows fed with açai oil had greater (P≤0.04) colostrum concentrations of immunoglobulins (Ig) G (1st and 2nd milking), IgG heavy chains, IgA (only at 1st milking), alpha-lactalbumin (1st milking), total protein, and antioxidant capacity against peroxyl radicals (only at 1st milking). Cows fed with açai oil had greater serum concentrations of globulin (only on the day of calving) and total protein (only on the day of calving) (P = 0.03). Calves born of cows fed with açai oil had greater serum concentrations of total protein (only 24 and 48 h after calving) and serum concentration of IgG heavy chain (only 24 h after calving) and globulin (only 24 and 48 h after calving) (P = 0.01). These data suggest that the addition of açai oil in the cow feed during the close-up dry period boosted immunity in their calves by altering the composition of colostrum.

Effect of dietary supplementation with grape residue flour on weight gain, metabolic profile, leukogram, proteinogram and antioxidant response in suckling lambs.

The objective of this study was to determine whether the addition of grape residue flour (GRF) in the diet of suckling lambs would improve their health and consequently enhance their growth. We used 48 lambs, 30 days of age divided into four treatments with four repetitions each, with each repetition consisting of three animals. The groups were identified as follows: G-0%, used as a control (without GRF) and G-0.5%, G-1% and G-2% referring to treatment with grape residue flour in doses of 0.5%, 1%, and 2% of inclusion in the concentrate, respectively. Lambs in groups G-1% and G-2% had higher final body weights, weight gain and average daily gain (ADG) compared to the other groups. GRF dietary supplementation had good antioxidant potential, being able to stimulate glutathione S-transferase (GST) activity and consequently reduce levels of reactive oxygen species (ROS) in lambs that consumed the highest dose of GRF (G-2%). GRF supplementation improved humoral responses, with increased serum levels of heavy-chain and light-chain immunoglobulins; however, there was a reduction in serum ceruloplasmin levels in these lambs. We observed higher concentrations of glucose and triglycerides in lambs in the 2% group. There were lower lymphocyte counts in lambs that received GRF. Lambs supplemented with the highest doses of GRF (G-1% and G-2%) had lower total bacterial counts in the feces. We conclude that the use of GRF in the supplementation of suckling lambs improved animal health, as it stimulated the antioxidant and immune systems and consequently favored their growth.

Nutraceutical effect of vitamins and minerals on performance and immune and antioxidant systems in dairy calves during the nutritional transition period in summer.

We aimed to determine whether the use of injectable vitamins and minerals improves growth performance and immune and antioxidant responses in dairy calves during pre- and post-weaning period in summer. Twenty dairy calves (45 days of age) were randomized to two groups (10 each): control group (CON) and treated group [TREAT; injection providing 0.20, 0.80, 0.20, 0.10, 35 and 1 mg/kg of copper, zinc, manganese selenium, and vitamins A and E, during two periods (15 days pre- and 15 days post-weaning)]. The animals were weighed and blood samples were collected on days 1, 15, 30 and 45 of the study. Levels of serum copper, selenium, zinc, and manganese were measured on day 1; and the results showed that calves were not deficient in these minerals. The TREAT group had greater BW gain during the final third of the experiment. There was an increase in total leukocyte numbers as a result of elevation in neutrophil counts (day 45) and monocytes (days 30 and 45) in the TREAT group. This group also had lower reactive oxygen species (ROS) content (days 15, 30 and 45) and lipid peroxidation (LPO; days 15 and 45). Furthermore, the TREAT group had greater antioxidant capacity against peroxyl radicals (ACAP; days 15 and 30), activities of the enzymes glutathione peroxidase (GPx; days 15, 30 and 45) and superoxide dismutase (SOD; day 15), concentrations of total serum proteins (day 30), serum globulin (days 15 and 30), ceruloplasmin (day 15), tumor necrosis factor-alpha (TNF-α), interleukin-1, (IL-1; days 30 and 45) and interferon gamma (IFNγ; day 45), compared to CON group. High respiratory rates during hot times of the day in all study calves was suggestive of heat stress. Taken together, the data suggest that mineral and vitamins injections increased the growth performance and boosted the antioxidant and immunological systems of dairy calves during the diet transition period in summer.

A prophylactic protocol to stimulate the immune response also controls infectious disease and, consequently, minimizes diarrhea in newborn heifers.

The immunostimulatory and immunomodulatory properties of selenium (Se), an essential trace element for animals, has increase its use because may prevent/or reduce the occurrence of infectious diseases. Thus, the aim of this study was to verify whether Se and vitamins (A and E) applied via subcutaneous associated with secnidazole via oral exert positive effects in the antioxidant and immune systems, as well as whether prevent infections caused by protozoan and bacteria, and consequently, reduce the number of cases of diarrhea in heifers. Thirty-two newborn Holstein heifers were divided into two groups with sixteen animals each: the control group and the treated group that received sodium selenite (0.2 mg/kg) and vitamins A (35 mg/kg) and E (1 mg/kg) with one day of life, and a second application associated with secnidazole (400 mg/animal) on day 10 of life. Sample collection (blood and feces) were performed on days 1, 15, 30, 45 and 60 of life. Heifers from the treated group showed higher hematocrit values compared to the control group on day 60 of life, while total serum protein levels were higher on days 15 and 30. The ceruloplasmin (days 15, 30 and 60), IgG of heavy chain (days 15, 30, 45 and 60), IgG of light chain (days 45 and 60) and haptoglobin (days 15, 30, 45 and 60) were higher in the treated group compared to the control group. Serum levels of glucose decreased in treated animals on day 60 of life, while serum levels of albumin, triglycerides, urea, cholesterol, thiobarbituric acid reactive substances, reactive oxygen species and glutathione S-transferase activity did not differ between groups. Secnidazole was able to prevent infections caused by Giardia duodenalis in the first few days of life, but no difference was observed between groups. Moreover, there was no difference on total bacteria count and the incidence of diarrhea between groups. No difference on weight gain was observed on day 60 of life, but on day 210 of life treated animals had higher weight gain compared to the control group. Based on these evidences, we concluded that the injectable application of Se and vitamins (A and E) associated to secnidazole can improve the immunological system, and consequently, favor animal's performance.

Feline Toxoplasmosis: Tumor Necrosis Factor, Nitric Oxide, and Free Radicals in Seropositive Cats.

Toxoplasma gondii is a cosmopolitan protozoan that causes disease in several species, including humans. In cats, these infections are usually asymptomatic, but in other species they can lead to high levels of inflammatory and cell damage markers, causing cellular damage. Therefore, the aim of this study was to measure levels of tumor necrosis factor (TNF-α), reactive oxygen species (ROS), and nitric oxide (nitrite/nitrate-NOx) in the serum of cats seropositive for T. gondii. Initially, we investigated the presence of antibodies against T. gondii in cats in the city of Concordia, Santa Catarina, Brazil, with the use of indirect immunofluorescence (IFA), and found 30 cats seropositive for T. gondii and 30 seronegative cats. In this study, seropositive cats showed higher levels of TNF-α, ROS, and NOx compared to seronegative cats. Although cats do not show clinical signs of disease, constant inflammatory response can cause cell damage, which over time may adversely affect the animal.