Genetic parameters and correlations for behavioural response traits towards humans in South African Black ostriches.

1. The aim of this study was to estimate heritability and genetic correlations, first among behavioural responses of juvenile South African Black ostriches towards humans and secondly with slaughter weight and skin traits.2. Behavioural traits, such as willingness of the birds to approach humans, keeping a distance from the human observer and allowing touch interactions by a human were recorded (n = 1012 birds). In addition, slaughter weight, skin size, scores for nodule size, nodule shape and the presence of hair follicles were recorded.3. Single- and multi-trait animal model analyses performed on the data using ASReml4 revealed high heritability estimates of 0.44 for allowing touch interactions and 0.48 for both willingness to approach and keeping a distance from the human observer. In addition, significant genetic correlations among behavioural response traits were estimated, ranging from -0.99 between keeping a distance and willingness to approach the human observer, to 0.87 between allowing touch interactions and willingness to approach the human observer.4. In contrast, genetic correlations of behavioural response traits with most slaughter and skin traits were low, variable, and not significant. The exception was hair follicle score, which appeared to be unfavourably correlated with key behavioural traits.5. This study suggested that the temperament of ostriches could be improved by selection of birds that demonstrate willingness to associate with humans without compromising slaughter weight or skin traits.

Meat quality, skin damage and reproductive performance of ostriches exposed to extensive human presence and interactions at an early age.

The effect human presence and interactions performed after hatch to 3 months of age has on ostrich meat quality, skin damage and reproductive performance at a later age was investigated in 416-day-old ostrich chicks. The chicks were allocated to one of the three treatments, which varied with regard to exposure to human presence and care for 3 months post-hatch: HP1-extensive human presence with physical contact (touch, stroking), gentle human voice and visual contact; HP2-extensive human presence with gentle human voice and visual contact without physical contact; S-standard control treatment, where human presence and visual contact were limited to routine management, feed and water supply only. Carcass attributes (carcass weight, dressing percentage and drumstick weight), meat quality traits (pH, colour and tenderness) and skin traits (skin size, skin grading and number of lesions) were evaluated on twenty-four 1-year-old South African Black (SAB) ostriches. Reproductive performance (egg production, average egg weight, number of clutches, clutch size, chick production, average chick weight, fertility and hatchability percentage) were recorded for the first three breeding seasons of 23 SAB pair-bred females from this study. No differences in carcass attributes, meat quality, skin traits and reproductive performance were found between treatments (P > 0.05). It was evident that exposure of day-old ostriches to extensive human presence and interaction as chicks did not influence carcass attributes, meat quality or skin traits at slaughter age, but more importantly, it did not compromise their reproductive performance.

Ostrich ejaculate characteristics and male libido around equinox and solstice dates.

The study evaluated the effect of time of the year in which changes in photoperiod occurs on ostrich semen characteristics and male libido. Semen was collected for 5 days before, on and 5 days after winter solstice (21 June 2016), spring equinox (22 September 2016), summer solstice (21 December 2016) and autumn equinox (20 March 2017) in the southern hemisphere. Semen was collected from 10 South African Black ostrich males (average age ± standard deviation; 4.5 ± 2.27 years) using the dummy female. Semen volume, sperm concentration, total sperm per ejaculate, sperm motility traits, percentage of normal sperm, head and tail abnormalities and percentage of affected sperm in the hypo-osmotic swelling test (HOS) were evaluated. Male libido defined as the willingness of males to mount the dummy female was also recorded. Semen samples collected around summer solstice, spring and autumn equinox were higher in sperm concentration and sperm output compared with winter solstice (P < 0.05). Study periods did not influence semen volume, sperm motility traits, the percentage of normal sperm, head abnormalities and HOS. Tail abnormalities were higher around winter solstice than around spring equinox (P < 0.05). Male libido and the success of semen collection were significantly higher around spring equinox (P < 0.05). Changes in photoperiod in the southern hemisphere do not affect semen production in ostriches. However, high sperm output and male libido around spring equinox and summer solstice dates suggest that these periods may be preferred for semen collection for artificial insemination and storage purposes.

Appraisal and standardization of curvilinear velocity (VCL) cut-off values for CASA analysis of Japanese quail (Coturnix japonica) sperm.

One of the basic steps in objective analysis of sperm motility is the subdivision of a motile sperm population into slow, medium and rapid categories based on their velocity. However, for CASA analysis of quail sperm, the velocity values for categorization of slow, medium and rapid sperm have not yet been standardized. To identify the cut-off values of "velocity curvilinear" (VCL) for quail sperm categorization, we captured and analysed 22,300 tracks of quail sperm using SCA® -CASA. The median and mean VCL values were 85 and 97 µm/s. To define the VCL cut-off values, we used two methods. In the first, we identified the upper (rapid sperm) and lower (slow sperm) cut-off values using: (i) median VCL ± 25% or ± 50% or ± 75% of median VCL value; (ii) first and third quartile values of VCL data (i.e. 25% cut-off setting); and (iii) 33% and 66% of VCL data. Among these settings, sperm categories and their corresponding motility characteristics recorded using the "25%" setting (i.e. slow ≤36 ≤ medium ≤154 ≤ rapid) were found the most realistic and coherent with male ranking by fertility. In the second method, we calculated heteroscedasticity in the total VCL data using PCA and the two-step clustering method. With this approach, the mean of the high and low clusters was 165 and 51 µm/s, respectively. Together, the mean from two methods suggested that, for SCA® -CASA categorization of quail sperm, sperm should be classed as "rapid" at VCL ≥160 µm/s and "slow" at VCL ≤45 µm/s.

Ostrich (Struthio camelus) embryonic development from 7 to 42 days of incubation.

1. Hatching success of ostrich eggs is poor (50-60% of fertile eggs). The current study was designed to identify the timing of key stages in the development of the ostrich embryo. 2. Growth of both embryo and wing length during 42 d of incubation was comparable and approximately linear, with a more or less weekly doubling in size up to 35 d of incubation. 3. The embryo eye size increased more rapidly than beak length and reached a maximum of ~16.2 mm by 28 d of incubation, whereas beak length increased continuously until hatching at 42 d. 4. Linear regression equations were derived from morphometric measurements of embryos between 7 and 42 d. 5. Information stemming from these results can be used to estimate the age of dead-in-shell embryos in an attempt to identify timing of incubation problems that potentially result in low hatchability of fertile eggs.

Embryonic development in the ostrich (Struthio camelus) during the first 7 days of artificial incubation.

1. Early development of ostrich embryos was investigated in relation to time of egg collection and genotype. 2. A total of 321 ostrich eggs were collected during the 2008 and 2009 breeding seasons and the development of the embryo for up to the first 168 h of incubation was described and analysed. A sample of the incubated eggs was weighed and opened daily to investigate developmental changes. 3. In fresh eggs, the blastoderm contained a round, translucent dark area pellucida (AP) in the centre, with a surrounding thin white ring, likely to be the beginning of the area opaca (AO). Fresh eggs were considered infertile if the blastoderm was absent and instead numerous white droplets were present surrounded by vacuoles. 4. The average blastoderm area of a fresh fertile egg was 15.8 mm(2), increasing to 143.3 mm(2) after 2 d of incubation. By 72 h of incubation the area vasculosa (AV) was discernible in the posterior half of the blastoderm. 5. At 48 h of incubation the blastoderm area in eggs from the South African Black genotype (SAB) × Zimbabwean Blue genotype (ZB) crosses (104.5 ± 18.6 mm(2)) was lower than the pure SAB (141.0 ± 10.5 mm(2)), ZB (161.7 ± 13.5 mm(2)) and ZB × SAB crosses (166.1 ± 14.2 mm(2)). 6. Embryo length was 5.01 mm after 72 h of incubation and 14.5 mm after 168 h of incubation. At 168 h of incubation AV lengths for both ZB × SAB (53.2 mm) and SAB × ZB crosses (54.1 mm) were longer than in embryos from the pure breeds. 7. Results from this study can be put to practical use when determining whether eggs are infertile or fertile and also in investigating the age of early embryonic mortalities.

In vitro initiation of the acrosome reaction in the emu (Dromaius novaehollandiae).

1. An assessment of the efficiency of the acrosome reaction (AR) provides an important predictor of the fertilizing potential of semen and for diagnosis of the causes of infertility. A standardized protocol was therefore developed for initiation of the acrosome reaction in emu spermatozoa in vitro, and the role of CaCl2 or perivitelline membrane (PVM) proteins in determining the outcome of the reaction was investigated. 2. The acrosome reaction (assessed by FITC-PNA) was successfully induced in live spermatozoa by incubation for 2 min in NaCl-TES medium supplemented with 5 mM CaCl2. The maximum response was 32% live acrosome-reacted spermatozoa (LAR) achieved after 10 min incubation. 3. Compared to the outcome with 5 mM CaCl2 or PVM protein alone, the response was significantly better with a combination of PVM protein and CaCl2. 4. A significant variation in the percentage of LAR spermatozoa among individual males was observed. No treatment affected the percentage of dead acrosome-reacted spermatozoa. 5. The results emphasize the important role played by both PVM proteins and Ca(2+) in the in vitro initiation of the acrosome reaction.

Liquid storage of Ostrich (Struthio camelus) semen at 5 °C through intermediate dilution.

Dilution rate, dilution temperature and storage time have been recognized as vital steps in the processing of semen for storage before artificial insemination. The objective of this study was to determine optimal dilution and dilution temperature with an ostrich-specific semen extender for chilled storage. Four preselected ostrich (Struthio camelus var. domesticus) males, known for their ease of collection and specific semen quality parameters, were collected using the "dummy" female method. Dilution of 384 semen samples, at rates of 1:1, 1:2, 1:4 and 1:8 semen/diluent ratio with a diluent set at 5, 21 and 38 °C was performed and stored for 48 h at 5 °C. In vitro sperm function tests were conducted to evaluate treated semen during different storage intervals of 1, 5, 24 and 48 h. Motility and kinematic parameters were measured by the Sperm Class Analyzer®, the percentage live sperm measured by fluorescence SYBR14®/PI (LIVE/DEAD®), the percentage of sperm able to resist the hypo-osmotic swelling (HOS) stress test and sperm morphology determined by Nigrosin-Eosin staining. Progressive motility (PMOT), motility (MOT), sperm kinematics, LIVE and HOS were best (P < 0.05) maintained at a higher dilution of 1:4-1:8. The beneficial effect (P < 0.05) of a higher dilution temperature (21 °C) was prominent in terms of PMOT at a higher dilution. Storage of chilled semen at 5 °C requires dilution, at interpolated rates of 1:6-1:7, together with an extender temperature of 21 °C, to maintain optimal sperm function with minimal loss over a 48 h storage period.

The role of the male cloacal gland in reproductive success in Japanese quail (Coturnix japonica).

The adult male Japanese quail has a well developed cloacal gland that produces meringue-like white foam. The physiological significance of the cloacal gland and its foam is still unclear. Therefore, we conducted two experiments to establish the functional role of the cloacal gland and its foam in natural mating and oviducal sperm transport. In the first experiment, artificial insemination of equal numbers of spermatozoa diluted in foam extract and normal saline once in a week were used to determine the role of foam in sperm transport in the female oviduct. After artificial insemination, eggs were collected to measure fertility, the duration of the fertile period, sperm holes and attached spermatozoa in the perivitelline membrane. Higher (P<0.05) fertility and greater duration of the fertile period were observed when semen was inseminated along with foam extract compared with normal saline. Further, the sperm holes and trapped spermatozoa in the perivitelline membrane were also higher (P<0.05) in the presence of foam extract. In the second experiment, two males with bigger and smaller cloacal gland areas were allowed to mate with a female. The mating attempts of males with larger cloacal gland were more successful (P<0.05) than males with smaller cloacal glands. Our results indicated that cloacal foam improves sperm transport in the female oviduct and that males with larger cloacal gland areas are preferred during mating.

The ostrich (Struthio camelus) ejaculate--effects of the method of collection, male age, month of the season, and daily frequency.

1. Over three breeding seasons on a farm in Poland, semen was collected from 11 ostriches using the dummy and the teaser method to study the effects of the method of collection, male age, month in the breeding season, and daily collection frequency on ejaculate characteristics. 2. A total of 259 ejaculates were collected, with an average volume of 1·28 ± 0·6 (±SEM) ml. Sperm concentration was 3·34 ± 0·08 × 10(9)/ml, the total number of spermatozoa 4·32 ± 0·22 × 10(9), and motility 4·56 ± 0·04. 3. There was no difference in ejaculates collected by the dummy and teaser methods, but the between-individual variation was considerable. Ejaculate characteristics increased with male age and varied between months, with little evidence for seasonal decline. Daily collections for 10 days did not affect sperm output. 4. The results open up avenues for further research on development of a viable protocol for artificial insemination in ostriches and efficient semen storage. 5. The between-male variation suggests that the ejaculate output could be maximized through selection.

Extending the viability of emu spermatozoa during in vitro storage by manipulation of temperature and diluent potassium concentration.

1. Survival of emu spermatozoa during in vitro storage is not affected by increasing the extracellular [K(+)] to the point where it does not adversely affect spermatozoa function. 2. In three experiments, the effects were studied of [K(+)] in a diluent in the range 12·5-80 mM/l on emu spermatozoa survival for up to 48 h at 5, 10 or 20°C. 3. At the end of the storage period, spermatozoa viability, motility, fertilising ability and morphology were measured. 4. In Experiment 1, spermatozoa viability and morphology were adversely affected after storage (P < 0·001) only in the diluent containing 80 mM/l [K(+)] whereas spermatozoa motility decreased as [K(+)] increased from 12·5 to 80 mM/l. 5. In Experiment 2, during storage at 5°C, the spermatozoa viability was comparable among any of the diluents (standard or modified) but morphology was better (P < 0·001) in all of the modified diluents than in the standard E3 diluent. 6. In Experiment 3, after 48 h of storage in a diluent containing 40 mM/l of [K(+)], the spermatozoa functions were better preserved at 10°C than at 5 or 20°C. 7. It is concluded that a higher than physiological level of potassium can be used in a diluent without detrimental effect on emu spermatozoa survival during 48 h storage and that the best outcome was with storage at 10°C rather than 5 or 20°C.

Genetic parameters for eggshell traits in ostriches.

1. A study was conducted on ~14000 ostrich eggs to estimate genetic parameters for eggshell traits that could benefit the hatchability of ostrich eggs. Traits measured included the number of pores on the eggshell, the average diameter of these pores, the total area of pores on the eggshell, permeability (pore area/shell thickness) and eggshell thickness. 2. Heritability estimates ranged from 0·16 for total pore area to 0·41 for the natural logarithm of pore count. The heritability estimates for water loss on 21 and 35 d (WL21 and WL35) of incubation were high at 0·23 and 0·24, respectively. 3. On a genetic level, pore count was negatively correlated with average pore diameter (-0·73) and shell thickness (-0·28), whereas it was positively correlated with total pore area (0·58), WL21 (0·24) and WL35 (0·34). The direct and maternal genetic correlations of pore count with total pore area (0·58) and permeability (0·59) were high and significant. Permeability was positively correlated to WL21 and WL35, both on the direct and maternal genetic levels. 4. The estimated genetic parameters indicate that it should be possible to select for the various eggshell traits in ostrich eggs, or for permeability and water loss. However, as a trait with an intermediate optimum, direct selection for permeability and other eggshell traits would not be straightforward, and the possible application of these results to improve hatchability of ostrich eggs in the future needs consideration.

Modification of spermatozoa quality in mature small ruminants.

This review is based largely, but not entirely, on the assumption that gamete quality is directly linked to sperm output and thus testicular mass, an approach made necessary by the absence of a large body of data on factors that affect gamete quality in ruminants. On the other hand, there is a change in the efficiency of sperm production per gram of testicular tissue when the testis is growing or shrinking, a clear indicator of changes in the rates of cell loss during the process of spermatogenesis, probably through apoptosis. We therefore postulate that the spermatozoa that do survive when the testis is shrinking are of a lower quality than those that are produced when the testis is growing and the rate of sperm survival is increasing. In adult small ruminants in particular, testicular mass and sperm production are highly labile and can be manipulated by management of photoperiod (melatonin), nutrition, genetics and behaviour ('mating pressure'). Importantly, these factors do not act independently of each other - rather, the outcomes in terms of sperm production are dictated by interactions. It therefore seems likely that spermatozoa quality will be affected by these same factors, but definitive answers await detailed studies.

Mineral profiling of ostrich (Struthio camelus) seminal plasma and its relationship with semen traits and collection day.

Successful assisted reproduction techniques, with specific focus on in vitro semen storage for artificial insemination, are dependent on certain key elements which includes the biochemical profiling of semen. The objective of this study was to complete an ostrich seminal plasma (SP) evaluation by inductively coupled plasma mass spectrometry (ICP-MS) among seven males at different daily intervals (day 1, 3, 7, 11, 15, 19, 21, 23, 25, 26, 27, 28) for a period of 28 days during spring (August to September) for mineral profiling. The effect of collection day and male on sperm concentration, semen volume and seminal plasma volume, was explored as well as the relationships amongst these specific sperm traits and SP minerals. Variation amongst SP mineral concentrations, accounted for by the fixed effects of sperm concentration, semen volume, seminal plasma volume, collection day and male, ranged from 18% to 77%. Male had the largest effect on variation in SP minerals, namely: phosphorus (P), potassium (K), calcium (Ca), sodium (Na), boron (B), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), molybdenum (Mo), barium (Ba), arsenic (As) and selenium (Se). Sperm concentration instigated fluctuations of P, magnesium (Mg), B, zinc (Zn), Fe, aluminium (Al), Se, manganese (Mn) and lead (Pb). Semen volume had an effect on Na, K, B, Pb and Ba while seminal plasma volume only influenced variation in Na. There were fluctuations among collection days of specific micro minerals, Ni and Mo, with initial Ni concentrations being relatively greater and Mo at lesser concentrations. Semen volume, seminal plasma volume and sperm concentration varied amongst males. Sperm concentrations during the initial collection days, 1 and 3, were less than that for days 7 to 28. Significant variation of SP minerals and sperm characteristics among ejaculates and males suggest an association of these specific elements with sperm function and are, therefore, considered to be of potential importance to success of assisted reproduction technology for the ostrich. The relationship amongst sperm concentration and collection day confirms the need to conduct an initial period of collection to stabilise a greater sperm concentration to optimise sperm numbers for artificial insemination purposes.

Ostrich specific semen diluent and sperm motility characteristics during in vitro storage.

The dilution of semen is a very important initial process for semen processing and evaluation, storage and preservation in vitro and efficient artificial insemination. The aim of the study was to evaluate the effect of two synthetic diluents (OS1 and OS2) on ostrich sperm motility parameters during in vitro storage. Formulation of OS1 was based on macro minerals (Na, K, P, Ca, Mg) and OS2 on the further addition of micro minerals (Se and Zn), based on mineral concentration determined in the ostrich seminal plasma (SP). Sperm motility was evaluated at different processing stages (neat, after dilution, during storage and after storage) by measuring several sperm motility variables using the Sperm Class Analyzer® (SCA). Processing (dilution, cooling and storage) of semen for in vitro storage purposes decreased the values for all sperm motility variables measured. The percentage motile (MOT) and progressive motile (PMOT) sperm decreased 20% to 30% during 24 h of storage, independent of diluent type. Quality of sperm swim (LIN, STR and WOB), however, was sustained during the longer storage periods (48 h) with the OS2 diluent modified with Se and Zn additions. Quality of sperm swim with use of OS1 was 6% to 8% less for the LIN, STR, and WOB variables. Male fitted as a fixed effect accounted for >60% of the variation for certain sperm motility variables (PMOT, MOT, VCL, VSL, VAP and ALH) evaluated at different processing stages. Semen from specific males had sustained sperm motility characteristics to a greater extent than that of other males during the 24-h storage period.

Factors related to shell deaths during artificial incubation of ostrich eggs.

The ostrich industry experiences a high rate of embryonic mortalities during artificial incubation of eggs. Embryonic deaths were studied from data recorded on 37,740 fertile eggs incubated artificially during the 1998-2005 breeding seasons. Roughly 10,000 eggs that sustained embryonic mortalities were classified according to the stage and nature of death, i.e. before 21 days of incubation, after 21 days of incubation, deaths after pipping and rotten eggs. Although infection may have played a role in approximately 1300 rotten eggs, no detailed knowledge of the pathogens involved was available. The remainder of deaths could not be related to pathogens and the deaths were thus generally referred to as non-infectious. The overall level of embryonic mortality in all the eggs studied was 28.5 %. Overall embryonic mortality was affected by incubator, with higher levels (57.0 %) found in eggs incubated in an African Incubator and also in eggs that were transferred between incubators during incubation (38.1%). Overall embryonic mortality also increased in eggs produced by older females. Eggs produced in the autumn had the highest level of embryonic mortality at 53.6 %, whereas eggs produced in the winter had a marginally higher level of embryonic mortalities of 29.2 % compared with eggs produced during summer (27.4 %). Eggs produced by South African (SA) Black males crossed to Zimbabwean Blue females had high levels of embryonic losses of 45.7 %. The embryonic mortality of eggs produced by SA Blacks or Zimbabwean Blue breeding birds subjected to pure breeding was similar at approximately 33-34 %, but embryonic mortality was improved in eggs produced by Zimbabwean Blue males crossed to SA Black females (27 %). Embryonic mortality was increased in eggs that were set directly (32.0 %) or subjected to longer than 6 days of storage (43.5 %). Embryonic mortality was affected by year. The results that were obtained will assist in determining non-infectious factors that have a negative effect on hatching success. Steps can thus be taken to eliminate such factors that may compromise hatching success.

Classification of ostrich sperm characteristics.

The success of assisted reproduction techniques is dependent on a sound foundation of understanding sperm characteristics to evaluate so as to improve semen processing. This study offers a descriptive basis for ostrich semen quality in terms of sperm function characteristics (SFC) that include motility, measured by computer assisted sperm analysis CASA (SCA(®)), viability (SYBR14/PI) and membrane integrity (hypo-osmotic swelling test). Relationships among these SFC's were explored and described by correlations and regressions. Certain fixed effects including the dilution of semen, season, year and male associated with semen collection were interpreted for future applications. The seasonal effect on sperm samples collected throughout the year suggested that it is prudent to restrict collections to spring and summer when SFC's and sperm concentration are maximized, compared to winter when these aspects of sperm quality are suppressed. Dilution of ejaculates helped to maintain important SFC's associated with fertilization success. The SFC's and sperm concentration varied among males, with specific males, having greater values for the percentage of motile (MOT) and progressively motile (PMOT) sperm, as well as sperm velocity (VCL, VSL, VAP) and linearity (LIN) variables. Males may thus be screened on these variables for inclusion in an artificial insemination (AI) programme to optimize fertility success rates.

Effect of proctodeal gland foam on sperm kinetics in Japanese quail (Coturnix japonica).

The proctodeal gland of the male Japanese quail produces thick foam that accompanies semen when it is transferred to the female. It is thought that this foam enhances fertilization by improving the motility of the sperm, but reports are conflicting because the effect of foam on sperm motility has only been assessed subjectively The velocity of individual sperm was not able to be measured accurately, variations were large, and small changes in motility could not be accurately evaluated. So, we tested the hypothesis that foam affects the motility of spermatozoa of Japanese quail by analyzing motility objectively using computer-assisted semen analysis and determining changes in sperm kinetics in the presence of different concentrations of proctodeal gland foam. The addition of 5% or 10% foam to the sperm suspension increased (P < 0.05) all sperm kinetic parameters (the curvilinear velocity, straight line velocity, the velocity of the average path, linearity, straightness, and beat cross frequency). As a result, the percentage of motile and progressive motile sperm also increased. All these parameters declined (P < 0.05) with a further increase in the concentration of foam to 15% and 20%. Furthermore, this effect was similar in males that were 8, 16, or 26 weeks of age. We conclude that sperm motility is enhanced by proctodeal gland foam, and this enhancement depends on its concentration.

Endocrine and testicular changes in a short-day seasonally breeding bird, the emu (Dromaius novaehollandiae), in southwestern Australia.

Seasonal changes in testicular morphology and blood plasma concentrations of LH, testosterone, and prolactin are described for captive male emus in southwestern Australia. Testicular mass and testicular testosterone did not differ between the non-breeding (spring-summer) and the breeding (autumn-winter) seasons. Nevertheless, the testes obtained in the breeding season (May and August) were nearly two fold greater in mass than those collected in the non-breeding season (October and February). The highest testicular concentrations of testosterone were observed in February and lowest in October, while the values during the breeding season were intermediate. The patterns of histological changes in the testes also indicate that emus breed over the autumn-winter months. Tubule diameter was larger in the breeding season than in the non-breeding season, whereas the relative volume of the interstitium was larger in the non-breeding and smaller in the breeding season. Moreover, during the autumn and winter months, plasma LH and testosterone concentrations were high. Outside this period, in spring and summer, the concentrations of these hormones were low. Prolactin concentrations rose around the winter solstice, after the initial increases in plasma LH and testosterone. The end of the breeding season, in early spring, was marked by a gradual decrease in plasma LH concentrations but a rapid fall in testosterone concentrations. Prolactin concentrations continued to increase and peaked near the spring equinox, several weeks after the breeding season ended, and then decreased to reach baseline values by mid-summer. These testicular and endocrine changes are consistent with observations that the emu is a short-day breeder in southwestern Australia. Reproductive activity in the male begins soon after the summer solstice, well in advance of the development of suitable breeding conditions, and is then terminated in spring before food resources become limited by the onset of the dry season.

Semen production by the emu (Dromaius novaehollandiae). 1. Methods for collection of semen.

Two methods for collecting semen from male emus using an artificial cloaca (AC) have been developed. In the first method, the male mounts the female teaser and the collector effects erection and subsequent ejaculation using the AC. The second method takes advantage of the development of sexual behaviour directed towards the semen collector and semen is collected when the male mounts the collector's back. Eight of 11 males were successfully trained with teasers and 5 of the 7 males trained without teasers ejaculated successfully. The ease of training varied between birds. The use of a teaser was very valuable, as the crouching behavior of the teaser elicited mating attempts in every male. The training and collection of semen was done by one person. Both methods can be used for routine collection of semen, as they take advantage of natural stimulation and the voluntary ejaculation reflex to which the birds adapted readily.