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.

Effects of the inclusion of açai oil in diet of prepartum Holstein cows on milk production, somatic cell counts and future lactation.

We measured the effects of açai oil in the diets of prepartum cows to evaluate health, milk production and quality. Sixteen Holstein cows were divided into two groups: SOY used as control, and AÇAI, test group. Occurred inclusion of 4% soybean or açai oils was provided in the concentrate starting at 20 days prepartum [d -20 to d 0 (partum-day)]. The AÇAI diet increased (P=0.01) milk production (d 10 and 20) and reduced somatic cell count (d 20). In milk, no effects were detected (P≥0.10) for concentration of fat, lactose or protein as well as in terms of serum concentration of calcium, albumin or triglycerides. AÇAI diet tended to increase (P=0.09) serum concentrations of total protein, glutathione transferase (d 4), and total antioxidant capacity (d 4 and 10) and increased (P≤0.05) globulin, gamma-glutamyl transferase, superoxide dismutase and glutathione peroxidase (d 4). Further, AÇAI diet reduced the serum concentration of creatine kinase (P≤0.05) (d 0, 4 and 10), reactive oxygen species (d 0 and 4) and lipoperoxidation (d 0) and tended to reduce aspartate transaminase activity (P=0.07; d 0 and 4). Açai oil in the diets in prepartum cows improved their health as well as milk production and quality.

Benefits of the inclusion of açai oil in the diet of dairy sheep in heat stress on health and milk production and quality.

The objective of this study was to determine whether the addition of açai (Euterpe oleracea) oil in the diets of lactating sheep under heat stress exerted beneficial effects on health as well as milk production and quality. Eighteen multiparous Lacaune sheep (2 or 3 parities; 28-30 days of lactation; average milk production of 1.7 L/sheep/day) were stratified by parity and milk production and were assigned randomly to 1 of 2 treatments (9 sheep/treatment): diet supplemented with 2% of soybean oil (SOY) or 2% of açai oil (AÇAI) in the concentrate for 14 days. The amount of oil added in the diet was equivalent to 0.65% of the total diet (dry matter basis). Blood and milk samples were collected on days 1, 10 and 14. On day 14, the AÇAI group sheep had lower serum concentrations of leukocytes, neutrophils, and lymphocytes than did the SOY group sheep. On day 14, AÇAI group sheep had lower serum concentration of triglycerides and urea, milk concentration of fat and total solid and milk lipid peroxidation than did SOY group sheep. However, on day 14, AÇAI group sheep had higher serum concentrations of glucose and globulin, serum and milk antioxidant capacity against peroxyl radicals, milk production and productive efficiency than did SOY group sheep. The fatty acids profile in milk did not differ between groups. These data suggest that açai oil improved the antioxidant activity in serum and milk and improved milk production and quality in dairy sheep under heat stress.

Health benefits of subcutaneous zinc edetate and diphenyl diselenide in calves during the weaning period.

The aims of this study were to investigate whether treatments with zinc edetate (Zn) and diphenyl diselenide ((PhSe)2) enhance performance, immune responses, protein metabolism, and oxidant/antioxidant status in calf serum and muscle. Animals were divided into four groups (n=6 each): control (without supplementation), and groups supplemented on days 50 and 70 of life with (PhSe)2, Zn, and a combination of (PhSe)2 and Zn. Animals treated with (PhSe)2 gained more weight by experimental day 220 than did the control group, but there was no difference by the end of the experiment (day 300). The absolute number of leukocytes and lymphocytes increased in groups Zn and (PhSe)2+Zn on day 20 of experiment, but decreased on day 40 in groups (PhSe)2, and (PhSe)2+Zn. The number of monocytes decreased in all groups compared with control. One of the principal findings was that (PhSe)2+Zn together had beneficial effects on protein metabolism, represented by increases total protein and globulin levels, compared with the control group. The combination of (PhSe)2 and Zn led to low levels of TBARS and ROS in serum and muscle, and stimulated antioxidant enzyme activities. Thus, supplementation with (PhSe)2+Zn may be a compelling approach to augmenting the calf antioxidant system during weaning.

Oxidative stress in dairy cows seropositives for Neospora caninum.

Bovine neosporosis is caused by the protozoan Neospora caninum and is one of the major causes of abortion in cows. Cattle are intermediate hosts of this parasite and may have asymptomatic or symptomatic infections. Therefore, the aim of this study was to evaluate oxidative stress marker reactive oxygen species (ROS), thiobarbituric reactive acid substances (TBARS) levels, glutathione S-transferase (GST), adenosine deaminase (ADA), and butyrylcholinesterase (BChE) activities in dairy cows seropositives for N. caninum (asymptomatic or symptomatic). Dairy cows (n=90) were tested by immunofluorescent antibody assay (IFA) for N. caninum and divided accordingly into three groups: the group A (seronegatives, n=30), the group B (seropositives and asymptomatic, n=30), and the group C (seropositives and symptomatic, n=30). It was observed increased levels of TBARS and reduced (P<0.05) BChE activity in seropositives either asymptomatic or symptomatic animals. ROS levels and ADA activity increased, and GST activity decreased (P<0.05) only in seropositives symptomatic dairy cows (the group C) compared to seronegatives dairy cows (the group A). Based on these results, it was observed that seropositive animals showed cell damage associated with oxidative stress and inflammation, mainly in those with symptomatic infections. Increased seric ROS levels and BChE activity may have influenced N. caninum pathogenesis in symptomatic animals due to increased cell damage and exacerbated inflammatory response, leading to the development of clinical signs.

Nanostructured cinnamon oil has the potential to control Rhipicephalus microplus ticks on cattle.

The aim of this study was to evaluate the capacity of pure and nanostructured cinnamon oil to control the infestation and reproductive efficiency of Rhipicephalus microplus on dairy cows. In vitro (stage I)-engorged female ticks were immersed in concentrations of 1.0, 5.0 and 10% of cinnamon oil on its pure form, and 0.5, 1.0, and 5.0% of the nanostructured form. 10% cinnamon oil (pure form) showed 100% efficacy, whereas concentrations of 1 and 5% were 62 and 97% efficacious, respectively. Nanocapsules and nanoemulsions containing cinnamon oil at 5% showed 95 and 97% efficacy, respectively. In vivo (stage II)-16 naturally tick-infested cows were divided into four groups of four animals each: Group A was composed of dairy cows sprayed with Triton (control); Group B was composed of dairy cows sprayed with cinnamon oil in its pure form (5%), whereas groups C and D were composed of dairy cows sprayed with nanocapsules and nanoemulsions, respectively, containing cinnamon oil at 0.5%. The ticks on each animal were counted on days 0, 1, 4 and 20 after spraying. Animals sprayed with pure and nanoencapsulated cinnamon oil carried significantly fewer ticks on days 1 and 4 post-treatment and were free of ticks on day 20 post-treatment. Ticks collected from these dairy cows (24 h after application) had impaired oviposition and larval inhibition, resulting in 90.5 and 100% efficacy when using pure and nanocapsules, respectively. In conclusion, the pure and nanostructured forms of cinnamon oil interfered with tick reproduction, whereas a significant acaricidal effect was found when applied onto cattle.

Influence of subclinical infection by agents of tick fever in milking dairy cows / Influencia de la infección subclínica por agentes de la fiebre por garrapatas en vacas lecheras

ABSTRACT Objective. The objective of this study was to evaluate the effect of subclinical infection by agents of tick fever in dairy cattle on milk parameters, such as production, composition, and quality. Materials and methods. The study was conducted in a private farm with 75 free-stall-housed dairy cows, from which 37 were evaluated. Monthly, individual milk samples were collected for compositional (fat, lactose, protein, and total solids) and quality (somatic cell counts (SCC)) analyses. In addition, blood samples were collected in order to identify cows that were tick fever-negative and positive by PCR for one or more of the following etiological agents: Babesia bovis, Babesia bigemina and Anaplasma marginale. Results. The results showed increased SCC in positive animals for at least one of the agents when compared to non-infected cows (p<0.05). Milk production was significantly lower in A. marginale positive animals (p<0.05). An increase of about 40% in milk solids content was found in B. bovis positive cows. Also, an increment of approximately 23% in lactose was found on cows positives for B. bigemina. Conclusions. We may conclude that the presence of at least one of these parasites in dairy cattle affects composition or quality of their milk.

RESUMEN Objetivo. El objetivo de este estudio fue evaluar el efecto de la infección subclínica por agentes de la fiebre por garrapatas en el ganado lechero en producción de leche, la composición y calidad. Materiales y métodos. El estudio se realizó en una finca privada con 75 vacas lecheras alojadas-libre puesto, y de estas se evaluaron 37. Se recogieron muestras de leche individuales mensuales para determinar la composición (grasa, lactosa, proteína y sólidos totales) y la calidad (recuento de células somáticas (SCC)). Además, se recogieron muestras de sangre para identificar vacas que fueron negativas a fiebre de garrapatas y positivos por PCR para uno o más de los siguientes agentes etiológicos: Babesia bovis, Babesia bigemina y Anaplasma marginale. Resultados. Los resultados mostraron un aumento de SCC en los animales positivos, al menos para uno de los agentes cuando se comparó con vacas no infectadas (p<0.05). La producción de leche fue significativamente menor en A. marginale animales positivos (p<0.05). Un aumento de aproximadamente el 40% en el contenido de sólidos de la leche fue encontrado en vacas positivas a B. bovis. También, un incremento de aproximadamente el 23% de la lactosa se encontró en vacas positivas para B. bigemina. Conclusiones. Se puede concluir que la presencia de al menos uno de estos parásitos en el ganado lechero afecta composición o calidad de su leche.

Toxoplasma gondii infection in dairy ewes: Vertical transmission and influence on milk production and reproductive performance.

The present study aimed to evaluate the transmission of toxoplasmosis (vertical and venereal) and its influence on milk production and reproductive problems of Lacaune sheep seropositives for Toxoplasma gondii. Males and females were serologically selected using indirect immunofluorescence method in three steps of the study. Step 1: In order to evaluate the influence of toxoplasmosis on milk production, the volume of milk produced by 40 sheep (22 seronegatives and 18 seropositives for T. gondii) was weekly measured throughout the lactation period. There were no significant differences between these two groups; in other words, toxoplasmosis did not affect milk production. Step 2: In order to assess T. gondii venereal transmission, five samples of semen from seropositive rams (n = 5) were tested by endpoint and real time PCR with two days of interval; however, these semen samples were PCR negatives for T. gondii. Step 3: To evaluate reproductive problems, 12 seropositive animals out of a flock of 68 pregnant ewes showed signs of reproductive problems, such as abortion or fetal resorption. T. gondii transplacental transmission was evaluated on blood drawn from newborn lambs (n = 41), and their respective seropositive mothers (n = 30) after single, double or triple births. Serological tests showed that 65.8% of the lambs had antibodies against this protozoan, indicating a high transmission from ewe to fetus during pregnancy. Therefore, it is concluded that toxoplasmosis in sheep may impair reproduction with a high percentage of vertical transmission.

Seroprevalence of Trypanosoma evansi infection in capybaras (Hydrochoerus hydrochaeris) from a nonendemic area in Brazil.

In South America, capybaras (Hydrochoerus hydrochaeris) as well as coatis (Nasua nasua) are the reservoir hosts of Trypanosoma evansi. Capybaras from a T. evansi nonendemic area in the State of São Paulo, southeastern Brazil, were culled because of an ongoing outbreak of Brazilian spotted fever; serum samples from these capybaras were tested for antibodies to T. evansi. Of the 172 sera tested, 17 (9.9%) were seropositive by card agglutination test, with antibody titers of 1:8-1:128; 14 (8.1%) of these 17 seropositive sera were also seropositive by indirect fluorescent antibody test, with antibody titers of 1:16-1:256. Both serologic techniques proved to be efficient, with similar results for detection of antibodies to T. evansi in capybaras from a nonendemic area in Brazil.

Relation between Neospora caninum and abortion in dairy cows: Risk factors and pathogenesis of disease.

Neosporosis is a parasitic disease cause by Neospora caninum, a parasite of great importance in livestock. This study aimed to evaluate the presence of antibody against N. caninum in dairy cattle with history of abortion, as well as to identify associated risk factors for neosporosis. Animals suspected of neosporosis (n = 130) after clinical examination were randomly selected. Sera samples from 29 farms were submitted to indirect immunofluorescence technique (IFA) in order to detect antibodies against N. caninum, and animals were considered positive if ≥ IFA 1:200. An epidemiological questionnaire was used to verify probable risk factors for neosporosis and their cause-effect relation. Serological results showed that 43.8% of the animals were seropositives for N. caninum. The univariate statistical analysis found a significant relation between neoporosis and age. The number of pregnancies and the number of years that the farms had been producing milk were found as associated risk factors for the disease either by univariate or by multivariate analyses. The cause-effect model found a possible relation between reproductive problems and positive serology for neosporosis (P = 0.06). Therefore, it was concluded that approximately 44% of dairy cows with history of abortion were seropositives for N. caninum and that age and the number of years that the farms had been producing milk are risk factors for parasite infection in dairy cattle.

Immunological response and markers of cell damage in seropositive horses for Toxoplasma gondii.

Toxoplasmosis is an important parasitic disease affecting several species of mammals, but little is known about this disease in horses. This study aimed to investigate the levels of several immunological variables and markers of cell damage in the serum of seropositive horses for Toxoplasma gondii. Sera samples of adult horses from the Santa Catarina State, Brazil used on a previous study were divided into groups according to their antibody levels for T. gondii determined by immunofluorescence assay, i.e. 20 samples from seronegative horses (Group A - control), 20 samples from horses with titers of 1:64 (Group B), 20 samples of horses with titers of 1:256 (Group C), and five samples from horses with titers of 1:1024 (Group D). Positive animals (Groups B, C, and D) had higher levels of immunoglobulins (IgM and IgG), pro-inflammatory cytokines (TNF-α, IFN-γ, IL-1, IL-4, and IL-6) and protein C-reactive protein, as well as lower levels of IL-10 (anti-inflammatory cytokine) when compared to seronegative horses (Group A). The nitric oxide levels were also elevated in seropositive horses. Therefore, we have found humoral and cellular immune responses in seropositive horses, and a correlation between high antibody levels and inflammatory mediators. Markers of cell injury by lipid peroxidation (TBARS) and protein oxidation (AOPP) were elevated in animals seropositives for T. gondii when compared to seronegatives. Therefore, seropositive horses to T. gondii can keep active immune responses against the parasite. As a consequence with chronicity of disease, they show cellular lesions that may lead to tissue damage with the appearance of clinical disease.

Occurrence of gastrointestinal parasites in goats from the Western Santa Catarina, Brazil.

This study aims to investigate the occurrence of gastrointestinal parasites in goats from the Western Santa Catarina, Brazil. Twenty four farms were analyzed in 17 different municipalities. Animals (n=217) from different production purposes (milk and meat) and age were randomly chosen. Fecal samples were collected from the rectum stored in plastic bottles and transported to the laboratory in portable coolers at 10 °C. The technique of centrifugal flotation with saturated sugar solution was carried out in order to investigate the presence of eggs, cysts, and oocysts of gastrointestinal parasites. In 88.9% of the investigated animals, it was observed that the presence of nematode eggs which belongs to the Strongylida order, after cultivation and larvae identification were identified as Haemonchus spp., Trichostrongylus spp., Teladorsagia spp., Cooperia spp., and Oesophagostomum spp. Eggs of Thysanosoma, Trichuris, Moniezia, and Neoascaris genus were also observed. Additionally, the presence of oocysts of Eimeria spp. and Cryptosporidium spp. as well as cysts of Giardia spp., and Entamoeba spp. were verified. In all the farms evaluated, the animals showed a single or mixed infection, with the highest occurrence of helminths belonging to the Haemonchus and Trichostrongylus genus, as well as the protozoan Eimeria.

Occurrence of gastrointestinal parasites in goats from the Western Santa Catarina, Brazil / Ocorrência de parasitas gastrintestinais em caprinos na região Oeste de Santa Catarina, Brasil

This study aims to investigate the occurrence of gastrointestinal parasites in goats from the Western Santa Catarina, Brazil. Twenty four farms were analyzed in 17 different municipalities. Animals (n=217) from different production purposes (milk and meat) and age were randomly chosen. Fecal samples were collected from the rectum stored in plastic bottles and transported to the laboratory in portable coolers at 10 °C. The technique of centrifugal flotation with saturated sugar solution was carried out in order to investigate the presence of eggs, cysts, and oocysts of gastrointestinal parasites. In 88.9% of the investigated animals, it was observed that the presence of nematode eggs which belongs to the Strongylida order, after cultivation and larvae identification were identified as Haemonchus spp., Trichostrongylus spp., Teladorsagia spp., Cooperia spp., and Oesophagostomum spp. Eggs of Thysanosoma, Trichuris, Moniezia, and Neoascaris genus were also observed. Additionally, the presence of oocysts of Eimeria spp. and Cryptosporidium spp. as well as cysts of Giardia spp., and Entamoeba spp. were verified. In all the farms evaluated, the animals showed a single or mixed infection, with the highest occurrence of helminths belonging to the Haemonchus and Trichostrongylus genus, as well as the protozoan Eimeria.

O presente estudo objetivou investigar a ocorrência de parasitas gastrointestinais que infectam caprinos na região Oeste de Santa Catarina, Brasil. Foram analisadas 24 propriedades localizadas em 17 municípios, totalizando 217 caprinos. Os animais de diferentes categorias de produção (leite ou carne) e idade foram escolhidos aleatoriamente. A coleta das fezes foi realizada diretamente da ampola retal dos animais, armazenadas em frascos plásticos e transportadas para o laboratório em caixas térmicas a 10 °C. A técnica de centrífugo-flutuação com solução saturada de açúcar foi utilizada para pesquisar a presença de ovos, cistos e oocistos de parasitos. Em 88,9% dos animais analisados foi verificada a presença de ovos de nematóides da ordem Strongylida e, após cultivo, foram identificadas larvas de Haemonchus spp., Trichostrongylus spp., Teladorsagia spp., Cooperia spp. e Oesophagostomum spp. Foram identificados também ovos de parasitos dos gêneros Thysanosoma, Trichuris, Moniezia e Neoascaris. A presença de oocistos de Eimeria spp. e Cryptosporidium spp., e cistos de Giardia spp., e Entamoeba spp. foram observadas. Em todas as propriedades avaliadas, os animais apresentavam infecções simples ou mistas, sendo a maior ocorrência de helmintos do gênero Haemonchus e Trichostrongylus, assim como pelo protozoário Eimeria.

Trichostrongylus and Haemonchus anthelmintic resistance in naturally infected sheep from southern Brazil.

The anthelmintic resistance in small ruminants is a common problem and concern worldwide. The aim of this study was to verify anthelmintic treatment efficacy in naturally infected sheep. This study was conducted on nine herds that used the same anthelmintic management for over a year. In each farm, the animals were divided into two groups: untreated control group (n = 5) and treated (n = 10) according to the number of eggs per gram of feces (EPG). The treatment effect was checked based on EPG results and larval culture performed before treatment and 10 days after treatment. Significant differences were not observed (P > 0.05) on EPG results between untreated and treated groups. The coproculture showed that the animals were infected primarily by Haemonchus spp., Trichostrongylus spp., Teladorsagia spp., Cooperia spp. and Oesophagostomum spp. In all farms, anthelmintic resistance by genera Haemonchus and Trichostrongylus was found, but this resistance varied greatly between farms. Haemonchus spp. showed resistance to closantel, levamisole, and albendazole. Trichostrongylus spp. was shown to be resistant to closantel, levamisole, and albendazole. The drugs tested showed to be efficient against the genera Teladorsagia, Cooperia, and Oesophagostomum. Based on these results, we conclude that the anthelmintic resistance to the tested drugs is a problem present in the farms evaluated.

Influence of tea tree oil (Melaleuca alternifolia) on the cattle tick Rhipicephalus microplus.

The aim of this study was to verify the influence of tea tree oil (TTO) (Melaleuca alternifolia) tested in its pure and nanostructured (TTO nanoparticles) forms on the reproduction of female Rhipicephalus microplus. For our purpose, female ticks were collected from naturally infected animals and treated in vitro with TTO (1, 5, and 10 %) and TTO nanoparticles (0.075, 0.375, and 0.75 %). In order to validate the tests, they were performed in triplicate using positive (amitraz) and negative (untreated) controls. It was possible to observe that pure TTO (5 and 10 %) and TTO nanoparticles (0.375 and 0.75 %) showed 100 % reproductive inhibition on female ticks. Additionally, pure TTO (1 %) also showed an acaricide effect (70 %), similarly to the positive control (78.3 %). This is the first study demonstrating the activity of pure TTO and TTO nanoparticles on female ticks. Therefore, based on these results, we were able to show that both forms and all concentrations of M. alternifolia affected tick reproduction by inhibiting egg laying and hatching. We were also able to show that TTO nanoparticles potentiated the inhibitor effect of pure TTO on the reproduction of R. microplus.