Effect of shading on the physiological and reproductive parameters in Nelore cows.

This study aimed to evaluate the physiological and reproductive parameters of Nelore cows under various microclimatic conditions. The experiment was performed in Central Brazil, which has a tropical climate with dry winters and rainy summers. The experimental groups were divided into an area with shading (5.8 trees/ha; n = 42) and an area with little shading (0.4 trees/ha; n = 42). The physiological (heart rate, respiratory rate, rectal temperature, surface body temperature, and vaginal temperature) and reproductive (estrus detection, conception rate, and rate of pregnancy loss) parameters were then assessed. The rectal temperature (p = 0.002); surface body temperature on the flanks, forehead, and shoulder (p < 0.001); and vaginal temperature (p < 0.001) of cows in the group with shading were significantly lower than those of cows in the group without shading. Estrus was higher (p = 0.08) in the shaded group; however, no effect was observed on conception and pregnancy loss rates. In conclusion, shading (5.8 trees/ha) provided better thermal comfort for Nelore animals in the tropical climatic region. However, this did not affect their performance after fixed-time artificial insemination.

P4/E2-based protocol for synchronisation of ovulation of mares during the breeding and non-breeding season.

Dispersed ovulation at the breeding (BS) and anestrus at non-breeding season (NBS) are major impediments to embryo transfer and insemination programmes. The present study aimed to evaluate a hormonal P4/E2-based synchronisation protocol in mares during both the BS and the NBS on ovarian/follicle behaviour. Mares underwent a hormone protocol to synchronise their ovulation during the BS (n = 8) and NBS (n = 10), starting (D0) with the insertion of an intravaginal device containing 1 g of P4 and 7 mg Estradiol Benzoate IM. (EB). On D9, the device was removed and injected with 0.25 mg of cloprostenol sodic IM and 2 mg of EB IM. Follicular behaviour was evaluated using a daily transrectal ultrasound (24/24 h) from D0 until ovulation. When the dominant follicle (DF) measured at least 35 mm, females were injected with 0.25 mg of gonadorelin acetate IM to induce ovulation. The DF on D0 were similar in animals between BS (18.9 ± 8.4 mm) and NBS (23.7 ± 9.2 mm; p = 0.2700). However, in the BS the DF was smaller (14.2 ± 4.7 mm) on D9 than during NBS (22.0 ± 7.1 mm; p = 0.0177). During the BS, the ovulatory follicle is smaller (p = 0.0042) than during NBS, measured at 33.5 ± 4.6 mm and 41.3 ± 2.8 mm, respectively. Ovulation time after P4 removal was similar during BS (173.1 ± 68.8 h) and NBS (192 ± 58.2 h; p = 0.3507). There was no difference towards an ovulation rate during BS (88%) and NBS (60%; p = 0.0978). There was no difference in spontaneous ovulation during BS (43%) and NBS (0%; p = 0.6085). This hormonal protocol would be an effective tool for inducing cyclicity/ovulation in mares during BS and NBS.

Viral diversity of Rhipicephalus microplus parasitizing cattle in southern Brazil.

Ticks are ectoparasites spread worldwide and are well known as vectors of many viruses of great importance to human and animal health. However, the viral diversity in ticks is still poorly understood, particularly in South America. Here we characterized the viral diversity present in Rhipicephalus microplus parasitizing cattle in the southern region of Brazil using metagenomics. Our study revealed the presence of viruses that had not been previously described in the region, including lihan tick virus (Phenuiviridae family) and wuhan tick virus 2 (Chuviridae family), as well as expands the biogeography of jingmen tick virus (Flaviviridae family) in Brazil. Also, we described three novel tymoviruses (Tymovirales order), named guarapuava tymovirus-like 1 to 3. We described the genomic and phylogenetic characterization of these viruses. Our study sheds light on the viral diversity of Rhipicephalus microplus in South America, and also expands the biogeography of tick viruses that were previously described only in Asia.

Occurrence and risk factors for Toxoplasma gondii and Neospora caninum in sheep of the Guarapuava region, Paraná, Brazil / Ocorrência e fatores de risco para Toxoplasma gondii e Neospora caninum em ovinos da região de Guarapuava, Paraná, Brasil

Toxoplasmosis and neosporosis are diseases that may affect production animals and cause significant economic losses. Given the importance of this fact, risk factors and occurrence of antibodies anti-Toxoplasma gondii and anti-Neospora caninum were determined for 81 sheep in seven farms of the Guarapuava region, state of Paraná, Brazil. Indirect fluorescence antibody test (IFAT) showed antibody frequency of 40.74% for T. gondii and 3.70% for N. caninum. The risk factors evaluated were: for T. gondii, direct contact of sheep with cats and for N. caninum, with dogs; abortion in the herd; and access of other animal species to the same water tank used by the sheep. CI (95%), Odds Ratio, and p value were determined by Fisher Exact Test. No statistical difference was observed between the occurrence of antibodies and risk factors associated with the presence of antibodies against both parasites. It may be stated that the protozoa T. gondii and N. caninum are found in the sheep herds of this region...(AU)

A toxoplasmose e neosporose são doenças que podem afetar os animais de produção causando perdas econômicas significativas. Sabendo disso, foram determinados os fatores de risco e a ocorrência de anticorpos anti-Toxoplasma gondii e anti-Neospora caninum em 81 ovinos de sete propriedades da região de Guarapuava, Paraná, Brasil. A pesquisa de anticorpos foi realizada por meio da Reação de Imunofluorêscencia Indireta (RIFI) e foi observada uma frequência de 40,74% para T. gondii e de 3,70% para N. caninum. Os fatores de risco pressupostos para ambas as infecções foram: o contato direto dos ovinos com felinos, para T. gondii, e com cães para N. caninum, presença de aborto no rebanho e o acesso de outras espécies animais ao mesmo bebedouro dos ovinos. Por meio do Teste Exato de Fisher foram calculados o IC (95%), Odds ratio e o valor de p, os quais não revelaram associação entre a ocorrência de anticorpos e os fatores de riscos analisados. Pode-se afirmar que os protozoários T. gondii e N. caninum estão presentes entre os rebanhos de ovinos dessa região...