Ovinocultura do Rio Grande do Sul: descrição do sistema produtivo e dos principais aspectos sanitários e reprodutivos

Maternal behavior scores and temperament of ewes under intensive and extensive handling systems

Maternal behavior has been related to ewe's reactivity, as more reactive ewes might have greater risk of presenting worse maternal ability. This study aimed to determine the association between maternal behavior score (MBS) of Corriedale ewes with their physiological and behavioral variables measured at weaning of their offspring within two handling systems. Data from 335 ewes with average (± SE) age of 3.1 ± 1.8 years and 46.5 ± 6.1 kg of body weight were used. Experimental farms were classified into two handling systems: intensive (n = 3) and extensive (n = 2), based on stocking density and nature of human-animal relationships. Maternal behavior was evaluated in the field within 24 h after delivery, using a 6-rated scale (1 = poor to 6 = excellent). This scale takes into account the distance the ewe takes from the lamb when the lamb is restrained by an observer. The temperament of the ewes was evaluated during an arena test, at the weaning of the lambs, and was divided into two phases: social isolation and human presence. Data were subjected to principal component analysis and logistic regression. Logistic regression of principal factor (PF) scores in MBS showed that physical activity during the isolation phase increased in 1.57 (CI: 1.02 to 2.42; P < 0.05) the probability of extensively handling ewes showing high MBS (≥4), while in intensively handling ewes, logistic regression showed that the number of vocalizations in both phases of the arena test increased in 1.64 (CI: 1.12 to 2.4; P < 0.05) the probability of ewes having high MBS. Albeit the handling systems are not comparable, MBS was positively associated with some behavioral variables measured at the arena test.

Cross-border surveillance of sheep and goat rabies in Brazil

Since Brazil has the largest territory in South America and borders 10 other countries, rabies control is strategic to prevent cross-border spread. However, prevention and control of rabies in small ruminants is neglected. The present study evaluated the spatiotemporal distribution and temporal trends of rabies in small ruminants in Brazil between 2005 and 2023. Official data on rabies case notifications and the population density of goats and sheep from the Brazilian states were used. Descriptive epidemiology and temporal analyses of high-risk clusters and trends were conducted. Rabies cases were reported in all states, except for the Federal District, Roraima, Amapá, Amazonas, and Rondônia. In sheep, 174 cases were reported, with an emphasis on Paraná (25.29 %), being highest. There were 64 cases in goats, with a highlight on Bahia (37.50 %) and Maranhão (18.75 %). However, Espírito Santo presented the highest incidence risk (IR) for goats and sheep. The highest peaks in IR occurred in 2005, 2006 and 2013. A temporal trend of decreasing goat cases was observed in northeastern Brazil from 2005 to 2023. In sheep, the Northeast region showed a downward trend in rabies cases. Three high-risk clusters were identified: the primary cluster for goats occurred in 2006, and for sheep, between 2005 and 2013. Rabies in small ruminants occurs across all Brazilian regions, with high-risk areas in the Northeast, Southeast, and South, as well as a risk of cross-border transmission. These findings support animal health authorities in strengthening rabies control for small ruminants and reducing the risk of transboundary spread.

Vitamin and mineral supplementation improves erythrocytic recovery and productive performance of infected by gastrointestinal parasites

ABSTRACT The objective of the present study was to evaluate the effect of a vitamin and mineral complex, associated with the application of an efficient anthelmintic, in parasitized lambs, with characteristic signs of gastrointestinal nematode infection, on hematological clinical parameters of clinical improvementand weight gain. 60 lambs Australian Merino breed, with 8 and 9 months of age, were segregated in four groups: control (no supplemetation); formula 1 (Iron Dextran, Organic Phosphorus, Cyanocobalamin and Vitamin k); formula 2 (Iron Dextran, Organic Phosphorus and Cyanocobalamin); and formula 3 (Vitamin k). Hematocrit, prothrombin time, total plasma proteins, color of the conjunctiva and weight gain were analyzed. The results were submitted to analysis of variance (ANOVA) through the repeated measures test. There was no statistical difference between treatments for the variables of hematocrit (P = 0.564), prothrombin time (P = 0.911) and plasma proteins (P = 0.6), for the conjunctiva color variable there was a difference (P = 0.052 ), with greater results for the groups supplemented with Vitamin K, Butafosfan, Cyanocobalamin and Iron (groups F1 and F3), as well as those same groups reached higher body weight at D35 (P = 0.023). It can be concluded that the administration of vitamin and mineral complex, associated with efficient anthelmintic, promoted a better performance in parasitized lambs.

Inactivated recombinant Escherichia coli as a candidate vaccine against Clostridium perfringens alpha toxin in sheep

Clostridium perfringens type A is the causative agent of gas gangrene and gastroenteric ("yellow lamb disease") disease in ruminants, with C. perfringens alpha toxin (CPA) being the main virulence factor in the pathogenesis of these illnesses. In the present study, we have developed recombinant Escherichia coli bacteria expressing rCPA and used it to vaccinate rabbits and sheep. Doses of up to 200 μg of rCPA used for inoculation, induced 13.82 IU.mL^-1 of neutralizing antitoxin in rabbits, which is three times higher than that recommended by the USDA (4 IU.mL^-1). In sheep, recombinant bacteria induced antitoxin titers of 4 IU.mL^-1, 56 days after the first dose. rCPA which was expressed, mainly, in inclusion bodies, was not found to influence the immunogenicity of the vaccine. The recombinant Escherichia coli bacterin, produced simply and safely, is capable of affording protection against diseases caused by C. perfringens CPA. The current findings represent a novel production method for CPA vaccines potentially applicable to veterinary medicine.

Multiple anthelmintic resistance in Southern Brazil sheep flocks

Gastrointestinal parasites represent an important cause of reduced productivity of sheep worldwide. As anthelmintic are still the main control tool for these parasites, this work evaluated the efficacy of commercially available active principles in 22 sheep flocks in the southern region of Rio Grande do Sul, Brazil. In each farm 10 sheep were randomly distributed in seven groups with the following treatments: abamectin; albendazole; closantel; levamisole; monepantel; trichlorphon and no anthelmintic (control). All flocks showed resistance to at least three anthelmintics and in 20 farms only two products demonstrated efficacy for parasitic control. In two farms, there was no susceptibility to the six active principles tested. The results of this study provide evidence that the common commercially available anthelmintic are not assuring effective chemical control of gastrointestinal parasitic infections in ovine flocks in the southern region of Rio Grande do Sul. Monepantel, the newest introduced drug in the Brazilian market was not effective in 18% of the flocks tested, confirming that the parasitic resistance can be established quickly after the introduction of new molecules mainly when alternative program of parasite control is not performed.

Seroprevalence of Brucella ovis in rams and associated flock level risk factors in the state of Rio Grande do Sul, Brazil

A cross-sectional study based on a planned probabilistic sampling was carried out to estimate animal and flock prevalence of Brucella ovis in rams, as well as to determine risk factors at the flock level. Data regarding the flocks were collected by means of a questionnaire applied on 705 farms in the state of Rio Grande do Sul, Brazil, using one-stage cluster sampling. From the 705 flocks, 20 (2.5%, CI95%: 2.0-3.1%) had at least one positive ram. At the animal level, out of 1800 rams, 52 were positive (2.89%, CI95%: 0.4-5.3%). Statistical analysis identified the following as risk factors: average age of rams in the flocks (PR: 1.99, CI95%: 1.19-3.32); farms larger than 5 km(2) (500 ha) on extension area (PR: 7.46CI95%: 2.03-27.43); and the lack of lambing paddocks (PR: 5.56, CI95%: 1.70-18.11). This study provided relevant information for authorities to elaborate plans for the first Brazilian state based B. ovis disease control and eradication program. To the authors' knowledge, this is the first study that shows the importance of lambing paddocks in order to keep pre-lambing and lambing ewes away from the rest of the flock, the lack of this infrastructure was considered an important risk factor for B. ovis.