Body fat and circulating leptin levels in the captive short-beaked echidna (Tachyglossus aculeatus).

It is possible that the reproductive strategy of the short-beaked echidna is related to seasonal changes in fat deposition and energy availability, regulated by seasonal changes in endocrine function. We predicted that circulating leptin levels would be directly proportional to adiposity during most of the year, but that a change in this relationship would occur during the pre-breeding season to allow increased fat deposition. To test this hypothesis, we made use of a captive colony of echidnas to describe and quantify changes in fat distribution and the adipostatic hormone leptin. First we assessed seasonal changes in circulating leptin levels, body mass and adiposity for three male and three female adult echidnas maintained on a standard diet. Second, we explored the relationship between circulating leptin levels and increased caloric intake for an additional five adult female echidnas that were provided with supplemented nutrition. Third we visualised fat distribution in male and female adult echidnas using magnetic resonance imaging (MRI) before and after the breeding season, to determine where fat is deposited in this species. For echidnas maintained on the standard diet, there were no seasonal changes in body mass, body fat or plasma leptin levels. However, female echidnas provided with supplemented nutrition had significantly elevated plasma leptin levels during the breeding season, compared to the pre-and post- breeding periods. MRI showed substantial subcutaneous fat depots extending dorso-laterally from the base of the skull to the base of the tail, in both sexes. Pre-breeding season, both sexes had considerable fat deposition in the pelvic/rump region, whilst the female echidna accumulated most fat in the abdominal region. This study shows that male and female echidnas accumulate body fat in the pelvic/rump and the abdominal regions, respectively and that circulating leptin may promote fattening in female echidnas during the breeding season by means of leptin resistance. However, further research is required to evaluate the precise relationship between seasonal changes in leptin and adiposity.

Investigating the utility of using fecal hormone metabolites as a reproductive management tool for captive short-beaked echidnas (Tachyglossus aculeatus).

This study demonstrates the utility of the analysis of fecal hormone metabolites as a reproductive management tool for captive short-beaked echidnas. Over three breeding seasons daily fecal samples were collected from female echidnas (n = 8) that were monitored continuously by video surveillance to confirm key reproductive events. Fecal progesterone metabolite concentrations were elevated above baseline values (448.0 ± 156.3 ng/g) during pregnancy and the luteal phase. However, compared to plasma progesterone the rise in fecal progesterone metabolite concentrations after copulation was delayed (3.3 ± 0.4 versus 8.3 ± 0.6 days, respectively), such that pregnancy was more reliably detected in its latter half when using fecal samples. Mating and oviposition were observed for 14 of the 19 pregnancies resulting in an estimated gestation of 16.7 ± 0.2 days (range 16.0-18.1 d). The estrogen enzyme-immunoassays tested (n = 3) in this study were not suitable for the fecal samples of the echidna. Fecal progesterone metabolites are an effective tool for confirming the timing and occurrence of estrous cycles in captive echidna colonies and can assist zookeepers in identifying possible causes of sub-optimal reproductive success without the unnecessary stress of repeated capture and anaesthesia for blood collection.

Optimizing captive short-beaked echidna (Tachyglossus aculeatus) fecal sample identification and hormonal analysis.

The objectives of this study were to develop a fecal marking protocol to distinguish male from female samples during the echidna breeding season and to determine if normalizing fecal progesterone metabolite data for inorganic content improves the detection of biologically relevant changes in metabolite concentrations. Over a period of 6 weeks, four echidnas were provided with green food coloring powder mixed into 20 g of their regular feed with the dose adjusted weekly by 0.05 g. The proportion of organic (feces) versus inorganic matter (sand) in the fecal samples of three echidnas was determined by combustion of organic matter. Hormonal data was then expressed as metabolite concentration per total dry mass (with sand) of extracted sample versus metabolite concentration per total mass of organic material (without sand). The optimal dose of food coloring powder was 0.30 g: this was excreted in the feces of all echidnas within 24 h of consumption with color present for two consecutive days. Correction for inorganic content (sand) did not significantly affect variability of fecal progesterone metabolite levels (mean CV ± SE with sand: 142.3 ± 13.3%; without sand: 127.0 ± 14.4%; W = 6, p = .2500), or the magnitude of change from basal to elevated fecal progesterone metabolite concentrations (mean ± SE with sand: 8.4 ± 1.7; without sand: 6.6 ± 0.5, W = 10, p = .1250). Furthermore, progesterone metabolite concentrations before and after correction for sand contamination correlated strongly (r = .92, p = < .001). These methods will facilitate future reproductive endocrinology studies of echidna and other myrmecophagous species.

Reproductive behaviour before and after oestrus and oviposition in the captive short-beaked echidna (Tachyglossus aculeatus).

CONTEXT: Most of our current knowledge regarding echidna reproductive behaviour is based on qualitative measurements; therefore, it is unclear if specific behavioural cues could be utilised in their captive reproductive management. AIMS: This study aimed to identify quantitative changes in general and reproductive behaviour of echidna breeding pairs and pregnant females that might facilitate the detection of oestrus and impending oviposition and provide a summary of reproductive behaviour observed in a captive colony over a three-year observation period. METHODS: Three echidna breeding pairs and two trios were monitored daily for seven reproductive and eight general behaviours during the 2020 breeding season. After confirmed copulation, females were monitored for four egg-laying and eight general behaviours until egg incubation. General observations of reproductive behaviours during the 2018-2020 breeding seasons were recorded as part of routine husbandry. KEY RESULTS: For breeding pairs, there was a significant rate of change over time before and after copulation for the behaviours 'urogenital sniffing', 'rolling' and 'copulation attempt'. For pregnant females, time engaged in 'pacing' significantly increased while 'time eating' and the 'quantity of food eaten' significantly decreased on the day of oviposition. We were not able to identify oestrus from specific behaviours, but our observations suggest that the female echidna's period of receptivity is less than 24h. CONCLUSIONS: The frequency that males express 'urogenital sniffing', 'rolling' and 'copulation attempt' toward the female can be used to alert zookeepers that copulation has likely occurred. Increased pacing, reduced feeding time and quantity of food eaten can aid zookeepers to identify impending oviposition. IMPLICATIONS: This study demonstrates that there are quantifiable changes in specific echidna behaviours that can be incorporated into zoo husbandry practices to improve the reproductive management of this species.

Lameness in dairy cows: farmer perceptions and automated detection technology.

This Research Reflection provides an overview of three interrelated topics: (i) lameness in dairy cows, demonstrating the underpinning importance of the condition, (ii) dairy farmer detection, diagnosis and treatment of lameness and associated foot lesions as well as dairy farmer perceptions towards the condition and (iii) lameness detection technologies, and their potential application on farm to automate the detection of lameness in commercial dairy herds. The presented literature clearly demonstrates that lameness is a major health issue in dairy herds, compromising dairy cow welfare and productivity, and resulting in significant economic implications for dairy farmers. Despite this, dairy farmers fail to perceive lameness as a serious threat to their dairy business. This restricted perception of the importance of lameness may be a product of limited ability to detect lame cows. Many automated lameness detection technologies have been proposed to assist dairy farmers in managing their herds. However, limitations such as cost, performance and dairy farmer perception of the usefulness of these technologies, has lead to poor uptake. It can, therefore, be concluded that there is a need to more thoroughly evaluate the effectiveness of these technologies under on-farm conditions, potentially in the form of a demonstration farm network. This will allow generation of the necessary data required to show dairy farmers that these technologies are reliable and are economically rational for their dairy business.

Understanding dairy farmer intentions to make improvements to their management practices of foot lesions causing lameness in dairy cows.

Foot lesions causing lameness in dairy cows have been demonstrated to adversely affect milk yield, reproductive performance and longevity, resulting in significant economic burden to individual dairy farmers and the dairy industry. Further, foot lesions compromise dairy cow welfare. Despite this knowledge, foot lesions remain a large problem in many dairy herds woldwide. Therefore, there is potential for dairy farmers to make changes to their current management practices of foot lesions. This study used the social-psychology framework, the Theory of Planned Behavior (TPB), to explore dairy farmers' intentions to make improvements to their current management practices of foot lesions in their dairy cows and to identify the underlying behavioral, normative and control beliefs facilitating and constraining this behavior. In accordance with the theoretical framework, Australian dairy farmers were invited to participate in an online questionnaire which included questions regarding intentions, attitudes, subjective norms and perceived behavioral control. Fifty-six dairy farmers completed the questionnaire. The overall intention of these dairy farmers to make improvements to their management practices of foot lesions in the next year was moderate. Dairy farmers believed improving their current management practices of foot lesions would improve animal welfare, increase milk production and was worth the cost involved (behavioral beliefs). They indicated that the opinions of consumers, staff, and animal welfare groups were important in their decision to make improvements (normative beliefs). Better equipment and facilities, improved knowledge and training, and a favorable cost-benefit ratio were perceived as factors that would enable dairy farmers to improve their management practices (control beliefs). While all of these beliefs may be considered as potential drivers to facilitate dairy farmers to change their management practices, the behavioral beliefs were identified as the priority beliefs that industry should target in the development of strategies to increase dairy farmer intentions to make improvements to their management practices of foot lesions.

A systematic review of tests for the detection and diagnosis of foot lesions causing lameness in dairy cows.

Foot lesions causing lameness in dairy cows are important economic and welfare issues. Prompt and correct detection and diagnosis are critical for improving economic and welfare outcomes. Few tests are currently available to aid the dairy farmer in the detection and diagnosis of foot lesions. The objectives of this systematic review were to identify those tests that have been investigated for the detection and diagnosis of foot lesions causing lameness in dairy cows, evaluate the methodological quality of the studies investigating the identified tests, compare the accuracy of the identified test, and determine which tests can be recommended for implementation on the farm based on accuracy and practicality for use by dairy farmers. A comprehensive literature search resulted in 2137 papers. After removing duplicates and performing relevance screening, 12 papers with 20 studies met the inclusion criteria. Pertinent data from each study were extracted using a standardised form. Eligible studies were grouped based on the objective of the test under investigation, resulting in the following groups of disorders: lameness, foot lesions, sole ulcer, and digital dermatitis. Methodological quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool which includes four domains: animal selection, index test, reference test and flow and timing. Incomplete reporting in the studies limited the assessment of methodological quality. The animal selection domain was particularly poorly reported. No single study could be classified as being at low risk of bias across all domains of the QUADAS-2 tool. One automated test was identified, while all others were manually operated. No studies reported the cost of the test in question and only two studies reported the time taken to carry out the procedures involved with using the test in question. It was not possible to compare the accuracy of these tests or recommend which tests are suitable for implementation on the farm. This was due to incomplete reporting of information and significant risk of bias in all studies.