Highlights
Pregnant ewes have an impaired immune system at around one week prior to lambing and at lambing time.
Calcium and magnesium supplementation improved antioxidant capacity of growing lambs.
Calcium and magnesium supplementation improved leukocyte functions in newborn lambs.
Calcium and magnesium supplementation improved live weight gain of lambs from birth to 4 weeks after birth.
This study investigated the feasibility and validity of using non-invasively collected ice urine samples to measure cortisol concentrations in Weddell seals. Radio-immunoassays were used to determine urinary cortisol, and spectrophotometric assay was used to determine creatinine concentrations. This allowed for urinary cortisol/creatinine ratios (UCCR) to be compared between pure urine and urine collected from the ice. Urinary cortisol/creatinine ratios values of ice urine proved an effective method of studying cortisol concentrations in Weddell seals as there was no difference between pure urine and ice urine UCCR values. There were no inter-sexual or age-related differences in UCCR values in either pure or ice urine.
Little is known of the current status of platypus (Ornithorhynchus anatinus) populations in the Murrumbidgee catchment and other west-flowing rivers in the Murray–Darling Basin. Platypus distribution in the Murrumbidgee catchment was determined from sightings, reports by government departments, the literature and a capture–release study. The platypus was found to be widespread in the catchment, including all subcatchment and elevation categories, but most reports were from the middle and upper subcatchments. Sixty-five captures of 55 individual platypuses were made during 61 trap-nights to 31 study sites in the Murrumbidgee catchment during 2009–10. Only three juveniles (all females) were captured and recapture rates were low, with only nine platypuses captured more than once. Adult males had body weights of 980–2180 g and body lengths of 42–60 cm (n = 32). Adult females weighed 795–1480 g and were 38–52 cm long (n = 20). Tail fat index was significantly affected by season and platypus age, while in comparison, season, platypus length and weight had a significant effect on tail volume index. This study established a baseline that provides a starting point from which the impacts of environmental disturbances or diseases occurring over time can be measured and investigated.
Seasonal changes in reproductive and acoustic behaviour are potentially affected by hormonal fluctuations; however, as it is difficult to routinely sample marine mammals, these associations are mostly inferred. Australian fur seals are vocal marine mammals that have a highly synchronous breeding season. The present study collected information on the testosterone concentration in faeces, vocalisations and behaviour of two captive male Australian fur seals to determine whether there are any associations between these variables. Positive associations were evident between the non-interactive agonistic behaviours (Head sway, Lay down and Head up) and an increase in calling rate of the bark calls in males. Barks were highest during August through to October, corresponding to the breeding period, while faecal testosterone levels peaked in September, coinciding with the high frequency in the calling rates of barks. Guttural threat calls were rarely heard throughout the year, but peaked in August. This call was not frequently heard but was associated with specific behaviours that were produced during more intense fighting interactions. This study presents preliminary information on the vocalisations, behaviour and hormone profiles for two captive Australian fur seals. Future studies with increased sample sizes from both wild and captive animals would clarify the intricate association between these factors.
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