Austral Journal of Veterinary Sciences

Swimming performance of adults and copepodites of Caligus rogercresseyi against different water flow speeds in presence or absence of light and host fish attractants

2024-04-03T09:56:53-03:00

The present study was conducted to determine the swimming ability of adults and copepodites of Caligus rogercresseyi at three different water flow speeds, considering the presence or absence of attractants such as light and fish (Salmo salar). A total of 360 gravid females, 360 adult males, and 720 copepodites were randomly selected from a sea lice hatchery and distributed into groups. Each group was placed in a plastic bucket within a tank, and exposed or not to two attractants (light or host fish) at different water flow speeds (0, 1 and 2 cm/s). The results showed higher migration of adults and copepodites in the presence of light than in its absence (P < 0.05); however, no significant differences related to sea lice swimming performance were found in the presence or absence of fish (P > 0.05). Water flow speed had no effect on either variable (P > 0.05). In the current study, adult C. rogercresseyi demonstrated superior swimming capabilities compared with copepodites.

Relationship between chronic diseases, hair cortisol concentration and welfare of housed dairy goats

2024-05-06T12:08:47-04:00

The aim of this study was to evaluate the relationship between seroprevalence of chronic diseases, hair cortisol concentration (HCC), and welfare of dairy goats housed throughout a productive cycle. Sixty multiparous dairy goats, over four years old, were selected. An animal welfare assessment was conducted using health indicators for goats, according to the AWIN protocol. Blood samples were also collected for haematology and determination of seroprevalence of chronic diseases, hair samples for determination of HCC, milk samples for chemical composition and somatic cell counts, and faecal samples for parasite load. Small Ruminant Lentivirus (SRLv) had a prevalence of 71.66%, Mycobacterium avium subspecies paratuberculosis (MAP) of 5%, Leptospira interrogans of 40% and Ovine Gammaherpesvirus type 2 (OvHV-
2) of 50%. The percentages of goats that tested positive for one, two or three diseases were 31.67%, 50% and 11.66%
respectively. Haematological alterations included hyperproteinaemia (84.94 ± 1.58 g/L) and hyperfibrinogenaemia (6.11
± 0.65 g/L) for those with one or two diseases, with significant differences being found (P < 0.05). The welfare indicators
related to health and the number of diseases were poor body condition, poor coat, poor udder conformation, and
mucosal lesions (P < 0.05). However, no significant differences were observed between HCC and the number of chronic
diseases in dairy goats (P > 0.05). Higher concentrations of cortisol in hair were found at 150 days of lactation (16.65 ± 1.39
pg/mg) compared to the mating season (9.55 ± 0.04 pg/mg) (P < 0.05). No associations were found (P > 0.05) between
the production, composition, and somatic cell counts in milk and cortisol concentrations and diseases. It was concluded
that the presence of chronic diseases in goats did not influence hair cortisol concentrations, possibly due to an effect of
adaptive tolerance to diseases, as occurs in other domestic species; however, there was an effect of the productive stage.

Serological evidence of Coxiella burnetii in sheep herds from Lonquimay valley in the Chilean Andes

2024-03-12T09:59:58-03:00

Coxiella burnetii is the causative agent of Q Fever, a worldwide zoonotic disease that causes acute flu-like illness and chronic manifestations in humans in the form of endocarditis, hepatitis, and other symptoms. Domestic ruminants are the most important reservoirs of the bacteria, transmitting infections to humans during the calving/lambing season through direct contact with contaminated fetal tissues or inhalation of dust particles. The aim of this study was to provide serological evidence and estimate the individual true seroprevalence of C. burnetii exposure in sheep herds in Lonquimay, and to characterize farmers’ knowledge of coxiellosis. A disease freedom survey was conducted in 30 sheep herds selected from the Indigenous Territorial Development Program database (PDTI). A total of 260 blood samples were tested using ELISA for C. burnetii antibody detection. Disease freedom and true animal-level prevalence were estimated, and a questionnaire was administered during farm visits to characterize farmers’ zoonotic knowledge. A positive result was found in 3% (1) of the sampled herds, and the true animal prevalence (mTALP) was higher than previous unpublished estimations (mTALP 4.2%, 95% PPI 1.6%–9%). The estimated probability of the study sheep population not being free of C. burnetii was 34%. A lack of knowledge regarding C. burnetii or the consequences of Q Fever was detected, along with risky behaviors that could facilitate pathogen transmission. This study revealed evidence of exposure to C. burnetii, with low individual and herd-level prevalence. Initiatives to improve zoonotic knowledge among farmers need to be implemented in the short term.

The First report of metals and metalloids on bone and claw tissues of Humboldt penguins (Spheniscus humboldti)

2024-07-03T09:56:13-04:00

Samples of bones (humerus) and claws of adult Humboldt penguins (Spheniscus humboldti) were opportunistically obtained from twenty-seven carcasses at two important nesting sites in northern Chile: Chañaral Island (CHI) and Pan de Azúcar Island (PAI). The concentrations of trace elements (Cu, Zn, Pb, Ni, Fe, Se, As, Br, Mn and Cr) were determined by X-ray fluorescence. The highest levels (mean ± standard deviation, micrograms/g dry weight) of Cu (26.57 ± 4.08), Zn (163.9 ± 42.7), Pb (1.86 ± 1.53), Ni (0.31 ± 0.03), Se (7.70 ± 4.87) and Cr (0.25 ± 0.24) were detected in bones, whereas the highest levels of Fe (3,162 ± 1,579), As (6.75 ± 4.21), Br (0.12 ± 0.06) and Mn (76.7 ± 47.9) were found in claws. In bones, Se and Ni levels were higher (P < 0.05) in CHI than in PAI. In claws, the contents of Pb, Fe, and Mn were higher at CHI than those at PAI, whereas only As exhibited higher contents at PAI than those found at CHI. The trace element content in the claws and bones found herein may be the result of either acute or chronic exposure to penguins, respectively. These findings may serve as a baseline for further studies to design adequate and opportune plans to protect this vulnerable species.