Non-invasive monitoring of male and female numbat (Myrmecobius fasciatus: Myrmecobiidae) reproductive activity

The reproductive endocrinology of the highly endangered numbat (Myrmecobius fasciatus) is described for the first time. Patterns of faecal steroid secretion (progesterone [PM], oestradiol-17β [E2] and testosterone [TM] metabolites) were examined within a captive numbat population over 1 year and revealed a highly synchronized seasonal pattern of reproduction. TM secretion increased progressively from September to November, peaked in December and then decreased in February. All females displayed luteal phases (1-3), between late-November to late-March, in association with pregnant (Pr, n= 4), non-productive mated oestrous cycles (NMEC, n= 8) and non-mated oestrous cycles (NEC, n= 6). The mean oestrous cycle length was 30.2 ± 1.1. d (n= 11) and was comprised of a mean follicular (n= 11) and luteal (n= 18) phase length of 16.2 ± 1.6. d and 14.0 ± 0.8. d, respectively. No variation in mean luteal phase length or PM concentration according to cycle type (Pr, NMEC, NEC) or cycle number (1st, 2nd or 3rd cycle) was detected. Longitudinal profiling of PM secretion confirmed that the female numbat is seasonally polyoestrous and that the luteal phase occurs spontaneously. Changes in the secretion of E2 provided little instructive information on oestrous cycle activity. Mating success was 31%, with age and subject having no effect on mating success. Timing of introduction, of male to female, appeared to impact mating success, with paired animals introduced for a shorter time frame (≤14. d) prior to the first observed mating successfully producing young. Collectively, results of the present study confirm that PM and TM can be reliably used to index numbat reproductive activity

An evaluation of kikuyu-clover pastures as a dairy production system. 3. Dynamics of pasture composition and diet selection

A dairy system based on irrigated, perennial kikuyu (Pennisetum clandestinum) cv. Whittet - white clover (Trifolium repens) cv. Haifa pasture was compared at various stocking rates and nitrogen (N) fertiliser rates in a 3-year experiment. In the final year, observations were taken on 4 treatments comprising: 2.5 cows/ha, 0 kg/ha N; 3.75 cows/ha, 150 kg/ha N; 5 cows/ha, 150 kg/ha N; and 5 cows/ha, 600 kg/ha N. Daily milk yield, and pasture on offer, pasture composition and diet selection on Days 0, 2, 5 and 7 of a 7 day grazing, 21 day spelling rotation were measured. Milk yields ranged from 10.6-15.5 kg/d in May (P<0.01) and from 16.9-21.7 kg/d in October (P<0.05). Peak milk yield occurred on Day 3 of the grazing cycle in May and Day 4 in October, with increases of 1.85 and 0.75 kg/d, respectively, relative to milk yield at the start of the cycle. Clover % in the diet (DCLOV%) on the first day of the grazing cycle was the factor most closely related to milk yield (MY; kg/d). The across-seasons equation, where MONTH - 0 for May and 1 for October, was: MY (kg/d) = 11.77 + 3.94 MONTH + 0.069 DCLOV % (R2 = 0.84; P<0.001).Clover % in the diet (DCLOV%) was most related to pasture clover yield on offer (PCLOVY) with declining coefficients of selection for each day of the rotation. Dietary crude protein % declined linearly with day of the rotation at approximately 1.4% per day, and calcium and magnesium selected from pasture were also observed to decrease with day of the grazing cycle

Effect of field-weathered residues of pyriproxyfen on the predatory coccinellids Chilocorus circumdatus Gyllenhal and Cryptolaemus montrouzieri Mulsant

The residual toxicity of field-weathered residues of the juvenile hormone analogue insecticide, pyriproxyfen was evaluated against two coccinellids, Cryptolaemus montrouzieri Mulsant and Chilocorus circumdatus Gyllenhal, key predators of mealybugs and scales in citrus in southeast Queensland. Pyriproxyfen was applied as a high volume spray at 0.1, 1, 10, 25, 50 and 100 mg/L to late Valencia orange trees, and larvae and adults of C. montrouzieri and C. circumdatus were exposed to leaves picked at intervals varying from 0 to 112 days after spraying. The effect on fourth and fifth instar larvae and pupation and subsequent adult emergence, and on the viability of eggs from treated adults, was measured. Regression models were developed to relate larval mortality and egg hatch to pyriproxyfen concentration and weathering time. Pyriproxyfen killed larvae or prevented pupation of 50% of C. montrouzieri for 64 days at 10 mg/L and for a predicted 167 days at 100 mg/L; the effect on C. circumdatus was even greater, lasting a predicted 210 days at 10 mg/L. Egg-hatch (from adults exposed to treated leaves) was suppressed at 10 mg/L for 28 days in C. montrouzieri and for 50 days in C. circumdatus; at 100 mg/L, suppression extended to 50 days and a predicted 478 days, respectively. The combined effects on larvae and eggs of rates between 10 and 100 mg/L would be extremely disruptive to both species. Disruption was much less at 2 mg/L (lasting up to 3 weeks) and at 5 mg/L (lasting up to 7 weeks). Because of its potency against scale insects, pyriproxyfen may yet have a role in Integrated Pest Management (IPM) providing it is used very sparingly at dosage rates no greater than 2 mg/L

Using fire to manage species composition in Heteropogon contortus (black speargrass) pastures 1. Burning regimes

A reduction in the proportion of the desirable grass Heteropogon contortus(black speargrass) and an increase in the undesirable Aristidaspp . (wiregrasses) are evident in commercially grazed pastures. This paper evaluates the effectiveness of spring burning regimes over a period of 4 years (1989-92) in reversing this form of pasture degradation. Burning increased the proportion of H. contortus when pastures remained ungrazed but not when pastures were grazed, because cattle selectively grazed H. contortus after burning. Burning reduced the proportion of Aristida spp and other undesirable grasses such as Bothriochloa decipiens and Chloris divaricata. A strong ‘year of burning’ effect was evident. Burning increased recruitment of H. contortus which, in turn, increased plant density and later basal area. Burning reduced the basal area of Aristida spp initially by reducing tussock size and later by reducing tussock numbers. Results indicate that spring burning can restore pasture composition and that burning in at least 2 successive years appears to be necessary. Light stocking rates should be adopted so that the proportion of H. contortuscan be maintained and so that pastures can be burnt when and if required

A foliar rating system for comparing the resistance of banana cultivars grown as tissue-cultured plantlets in the laboratory to Fusarium wilt

A foliar rating system was developed to assess the progress of Fusarium wilt (Panama disease) caused by Fusarium oxysporum f. sp. cubense in seven banana cultivars differing in their resistance to race 1 of the pathogen. Plantlets were transplanted into unamended soil naturally infested with the pathogen, soil amended with urea and soil amended with aged chicken manure. A corm invasion score was also developed to assess the accuracy of the foliar symptom score as an indicator of cultivar resistance. On the basis of foliar symptom scores alone, the response of five of the seven cultivars in the chicken manure treatment corresponded to their known field response. However, the response of the other two cultivars, both susceptible to the pathogen in the field, fell into two categories. One had a high foliar symptom score and a correspondingly high corm invasion score, whereas the other had a low foliar symptom score and a high corm invasion score. Breeders need to be aware of the two categories of susceptible response, if inferior breeding material is to be rejected early on in a breeding program

Survival of conidia of sorghum ergot (caused by Claviceps africana) on panicles, seed and soil in Australia

Macroconidia of the sorghum ergot pathogen, Claviceps africana Frederickson, Mantle & de Milliano, survived in dried honeydew on soil for 13-14 weeks in a glasshouse at ambient temperatures, but for less than half that time on seed stored in a shadehouse over summer. Those on seeds stored at 4degreesC, however, survived for over a year (58-62 weeks). During summer, conidia on ergot-infected panicles buried in soil, or on the soil surface, survived for 7.5-12 weeks, whereas over winter the survival times were 4 weeks and 19-27 weeks, respectively. Macroconidia on infected panicles held above the soil surface survived for >38 weeks (8 calendar months) over winter, suggesting that they may play a role in the perennation of C. africana in Australia

Measurement of bovine body and scrotal temperature using implanted temperature sensitive radio transmitters, data loggers and infrared thermography

Synchronous and continuous measurement of body (BT) and scrotal temperature (ST) without adverse welfare or behavioural interference is essential for understanding thermoregulation of the bull testis. This study compared three technologies for their efficacy for long-term measurement of the relationship between BT and ST by means of (1) temperature sensitive radio transmitters (RT), (2) data loggers (DL) and (3) infrared imaging (IRI). After an initial pilot study on two bulls to establish a surgical protocol, RTs and DLs were implanted into the flank and mid-scrotum of six Wagyu bulls for between 29 and 49\ua0days. RT frequencies were scanned every 15\ua0min, whilst DLs logged every 30\ua0min. Infrared imaging of the body (flank) and scrotum of each bull was recorded hourly for one 24-h period and compared to RT and DL data. After a series of subsequent heat stress studies, bulls were castrated and testicular tissue samples processed for evidence of histopathology. Radio transmitters were less reliable than DLs; RTs lost >11\ua0% of data, whilst 11 of the 12 DLs had 0\ua0% data loss. IRI was only interpretable in 35.8\ua0% of images recorded. Pearson correlations between DL and RT were strong for both BT (r\ua0>\ua00.94, P\ua0\ua00.80, P\ua

Effect of storage time and conditions on the hardness and cooking quality of adzuki (Vigna angularis)

A storage trial of two varieties of adzuki (Vigna angularis), Bloodwood and Erimo, produced in Australia, was conducted to determine the effect of various combinations of temperature, humidity and length of storage on bean quality. The beans were stored for up to 6 mo under the following conditions: temperature (10, 20 and 30degreesC), relative humidity (RH) (40 and 65%). Storage of adzuki at elevated temperature (30degreesC) and low relative humidity (40%) resulted in the greatest loss of bean moisture, increase in hydration times and decrease in bean cooking quality, i.e. increased hardness of cooked beans. The best storage conditions for the preservation of adzuki quality were 10degreesC and 65% RH