Suchergebnisse

This study examined the effectiveness of control measures for caprine arthritis-encephalitis in a herd with 431 dairy goats in an intensive rearing system. All animals older than six months were initially tested by agar gel immunodiffusion (AGID) and separated into seropositive and seronegative. Control measures were implemented for two years and ten months. Five serological examinations were subsequently performed two by AGID and three by the Western Blot (WB) technique. In these tests, animals that tested negative in the previous serological examination were evaluated along with those older than six months which had not yet been examined. The effectiveness of control was evaluated based on the incidence of the disease. Seroconverted animals were stratified according to age, physiological status and dam serology. For the effect of time, logistic regression was performed at the 5% significance level, with values converted into likelihood. General incidence and incidence as a function of age and physiological status were evaluated by analysis of variance, with means compared by Tukey's test at 5% significance. The ratio test was used for incidence and physiological status, and the agreement between the AGID and WB tests was determined by the Kappa coefficient. Animals that seroconverted and were born to positive dams were compared with those born to dams negative at birth by the Chi-square test, and the same was applied for the number of discarded animals. Initially, 54.24% (179/330) positive and 257 seroconverted animals were identified after the start of control. Higher incidence occurred in the animals aged between 13 and 36 months and in lactating does. Seroconversions among offspring of seropositive dams were higher than in the offspring of seronegative dams (p < 0.001). High infection rates were identified in the sires. The obtained results were not satisfactory, as the measures did not help to prevent new cases, indicating that there are moments of infection yet to be elucidated. On farms that aim to control the disease, the following measures are required in addition to those already recommended: use of diagnostic tests with less frequency; application of high-sensitivity tests in the offspring; immediate separation of kids from dams at birth; separation of kids according to the serological status of the dams; inclusion of kids from unsupervised births in the group of kids from positive dams; and keeping positive and negative animals on different farms or greatly distanced. In herds for which there is an intention to establish control, it is important to determine whether the productive losses associated with the disease are greater than the costs of implementing more efficient measures.

The objective of this study was to analyze the immune responses of bucks to small ruminant lentivirus (SRLV) with a focus on the reproductive system of males with recent and chronic infection. A total of 12 bucks were selected, six seronegative and six seropositive with chronic natural infection for more than 18 months (chronic infection group). After selecting the animals, the six seronegative males were intravenously inoculated with caprine arthritis-encephalitis virus (CAEV)-Co viral strain at a titer of 10-5,6 TCID50/mL. After viral inoculation, this group was called the recent infection group and was monitored weekly with the chronically infected group for 180 days with blood serum and seminal plasma Western Blot (WB) analysis. Of the animals with chronic SRLV infection, 18.94% (50/264) showed anti-SRLV antibodies in at least one of the samples, and 81.06% (214/264) were negative. Anti-SRLV antibodies were detected in 27.27% (36/132) of the blood serum samples from this group, while 10.60% (14/132) were reactive in the seminal plasma WB test. The animals inoculated with CAEV-Co became seropositive after the third week of viral inoculation. In this group, 31.06% (41/132) of seminal plasma samples had anti-SRLV antibodies, and of these, 70.73% (29/41) coincided with blood serum results. Of the remaining 29.27% (12/41), the seminal plasma sample of only three animals (RIA2, RIA3, and RIA5) had anti-SRLV antibodies. One of the animals with a recent infection presented anti-SRLV antibodies only in seminal plasma samples, possibly due to virus compartmentalization. Intermittent viral shedding was observed in both biological samples, regardless of the infection stage. The immune response in bucks with recent SRLV infection is more significant than in chronically infected animals. Regardless of the stage of infection, there is a fluctuation in antibody levels, therefore, this creates a risk of false-negative samples when performing the diagnosis.

This study aimed to evaluate the production parameters of herds in 100 dairy family farms in the mesoregion of the Acre Valley, in Western Amazon, Brazil. To this end, the farms were divided into two levels of milk production. Data were collected from March to June 2016, using a 248-question semi-structured form and on-site observations. The information was recorded in SPSS® spreadsheets. Dairy farmers were divided into two clusters known as "high production cluster" (1,755.65 L ha-1 yr-1) and "low production cluster" (492.75 L ha-1 yr-1), using the K-means non-hierarchical method. Descriptive statistics was used and, with the aid of the multivariate cluster analysis, cattle ranchers were divided into the two clusters (high and low production). The results showed that the high-production cluster had larger total milk production (L milk cow-1 day-1) and family income within smaller areas and using less workforce. The farmers in this group also used more ear tags for cattle identification and more technologies such as electric fence and artificial insemination at a fixed time. We concluded that family farms should improve their management and receive technical assistance to strengthen their weaknesses in dairy-cow health and reproduction systems. Moreover, milk yield in these dairy farms should be improved to increase profitability of farmers.

Caprine arthritis encephalitis is a lentiviral disease that leads to considerable losses in goat farming. In the acute phase of viral infection, though antiviral antibodies are produced by the host's immune system, they are not sufficient to be detected by serological tests. Acute infections begin with an incubation period, during which the viral genome replicates and host innate responses are initiated. Matrix metalloproteinases (MMPs) are enzymes that play an important role in the physiological and pathological processes of tissue remodeling. The present study aimed to evaluate the expression of MMPs and their activity in the blood serum of goats experimentally infected with caprine arthritis encephalitis virus (CAEV). Five dairy goats, aged 3-4 years, were intravenously inoculated with CAEV Cork strain (titer: 105-6 TCID50/mL) after being tested negative for CAEV thrice at consecutive intervals of 30 days using western blot analysis and nested-PCR. The study included three stages: S1 or pre-infection stage; S2 or seroconversion stage, corresponding to the occurrence of first seroconversion; and S3 or post-seroconversion stage, corresponding to 23 weeks after seroconversion. Zymography was performed for the samples using gelatin zymography gels (12.5%), which were subjected to electrophoresis at 170V, 1A, and 300W for 50-70 min. The density of MMP-2 was found to be lower at S1 (1456.20 pixels) than that at S2 and S3 (1943.80 and 2104.40 pixels, respectively) (P < 0.05); and the density of MMP-9 was found to be lower at S3 (133.60 pixels) than that at S1 and S2 (359.60 and 370.60 pixels, respectively). The density of proMMP-2 was low at S1 and S3 (130.45 and 145.20 pixels, respectively). On the other hand, the density of proMMP-9 was statistically different between S1 and S3 (89.22 vs. 415.60 pixels). Both proMMP-2 and proMMP-9 were absent at S2. Thus, MMP-2 and MMP-9 exhibited opposite behaviors depending on the stage of infection. As the greatest activity of MMP-2 was detected at stage S3, we suggest that MMP-2 can be used as a biomarker for complementary diagnosis of acute CAEV infection. In addition, the presence of proMMP-13 can be used to indicate active viral infection.

The present study aimed to evaluate the anthelmintic effect of Carapa guianensis (andiroba) on gastrointestinal nematodes in sheep naturally infected in the Western Amazon. Toxicity tests with Artemia salina identified that the ethanolic extracts of the root and stem of andiroba showed an LC50% equal to 530 μg ml-1 and 170 μg ml-1, respectively. As concentrations 1.06mg / ml (andiroba root) and 0.34mg ml-1 (andiroba stem) were tested in groups of crossbred sheep, eaten from four to six months and weighing approximately 19.9 kg naturally infected by gastrintestinal nematodes. In addition, there will be a total of two treated groups and two control groups (negative and positive - 7.5% closantel). Foram extracts applied orally in a single treatment days 1,2,3,4,15,16,17,18. Or treatment lasted 30 days. Samples of fezes and blood foram collected at intervals of seven and 15 days respectively to assess the parasitic and hematological profile. The results showed a reduction in parasitic load of 86% and 59%, respectively, for the root and stem of andiroba in egg count per gram of feces, while in the group treated with closantel 7.5% the reduction was 66%. Regarding the number of third stage larvae recovered from sheep after treatment, it was observed that the groups treated with andiroba root and stem differed (p < 0.05) from the control group, with a reduction in the percentage of larvae from 70 and 55%, respectively. The phytochemical tests in the present study revealed the presence of bioactive metabolites that may be responsible for the anthelmintic activity. As for the hematocrit, there was no statistical difference in its values in the groups treated with andiroba root and stem, that is, in some way there was interference on the adult forms of the nematodes that compromised the hematophagism. Therefore, the extract of Carapa guianensis has anthelmintic potential, being a good alternative in the control of sheep endoparasitosis.