Nguni Bull Research Articles

Study the Effect of Extracted Low-Density Lipoprotein from Egg Yolk on the Cryopreservation of Nguni Bull Semen

Study the Effect of Extracted Low-Density Lipoprotein from Egg Yolk on the Cryopreservation of Nguni Bull Semen

21 Effect of egg yolk extracted low-density lipoprotein on cryopreserved Nguni bull semen

Egg yolk has been reported to have a beneficial effect on sperm quality following cryopreservation, and this led to its widespread use in semen extenders. However, egg yolk contains substances that inhibit respiration of sperm cells and diminish their motility rate. Moreover, it also contains low-density lipoproteins (LDL) that have a protective effect on sperm during the cryopreservation process. The objective of this study was improve cryopreservation of Nguni bull semen using egg yolk low-density protein. A total of 25 ejaculates were collected from 5 Nguni bulls aged 4 to 5 years using an electroejaculator during the natural breeding season. Collected raw semen samples were transported to the laboratory and evaluated for sperm motility, viability, plasma membrane, acrosome, and DNA integrity before dilution. Semen was randomly diluted with a sodium citrate extender supplemented with 20% egg yolk (control) and with 6, 8, 10, and 12% LDL concentrations. The diluted semen sample groups were equilibrated for 4h at 5°C. Following equilibration, semen was loaded into 0.25-mL straws and frozen in a controlled-rate programmable freezer. The groups of semen straws were then plunged into LN and transferred into LN tanks (−196°C) for storage. The frozen semen straws per treatment group were thawed at 37°C and evaluated for sperm motility, viability, plasma membrane, acrosome, and DNA integrity. Data were analysed with ANOVA using Stata V12 statistical software (StataCorp., College Station, TX), and treatment means were separated using Fisher’s protected t-test at the significant level of P<0.05. Sperm motility and membrane integrity were significantly higher (P<0.05) in frozen-thawed semen diluted with 8% LDL compared with the other concentrations. However, 6 and 8% LDL resulted in a significantly higher (P<0.05) live sperm, DNA, and acrosome integrity. Frozen-thawed semen diluted with 10 and 12% LDL resulted in the lowest percentages of sperm motility, live sperm, plasma membrane, acrosome, and DNA integrity following cryopreservation. In conclusion, extender containing 8% LDL resulted in improved Nguni bull semen parameters such as sperm motility, viability, plasma membrane, acrosome, and DNA integrity following cryopreservation. Further studies are required to determine the fertilizing capacity of semen diluted and frozen with LDL in vitro and in vivo.

15 QUANTIFICATION OF BULL SPERM TRAITS AS ASSESSED BY COMPUTER-ASSISTED SEMEN ANALYSIS AND THE RELATIONSHIP TO PREGNANCY RATE FOLLOWING CONTROLLED BREEDING

The bull’s contribution through artificial insemination to reproductive efficiency is of great biological importance. The objectives were (1) to compare the oestrous synchronization response of Bonsmara and Nguni cows; and (2) to find the relationship between cow’s conception rate (in vivo and in vitro fertilization) and bull sperm motility rate assessed by computer-assisted semen analysis (CASA) following AI. For the in vivo sperm fertility test, 100 Bonsmara and 482 Nguni cows were randomly selected and subjected to oestrous synchronization protocol and AI with frozen–thawed assessed semen by CASA before AI. Briefly at Day 0, cows were inserted with an intravaginal CIDR® (1.9 g), which was removed on Day 7. Prostaglandin was then administered (2 mL) on Day 8 and a heatmount detector was placed on the hindquarter of each cow. For the in vitro sperm fertility test, collected oocytes from slaughterhouse were in vitro matured (n = 360) and in vitro fertilized (sperm/mL) in 100-µL droplets (final volume) of BO-IVF medium per treatment bulls (Bonsmara or Nguni bull). The frozen/thawed semen straws of Bonsmara and Nguni bulls were randomly selected and used under the same IVF conditions. The thawed bull’s sperm characteristics were examined by CASA before in vitro fertilization. Data were analysed using ANOVA. Treatment means were compared using the Fisher’s protected least significant difference t-test. There was no significant difference in oestrous response for the Bonsmara (83.0%) and Nguni (90.8%) cows, respectively. The Bonsmara cows recorded a significantly higher pregnancy rate (59.0%) compared with the Nguni (37.1%) cows (P < 0.05). Sperm traits such as total motility (TM), progressive motility and rapid were found to be positively correlated with conception rate (r = 0.06, 0.03, and 0.08, respectively; P < 0.01), although correlations were low. There was no difference in the average frozen–thawed sperm TM rate of Nguni (92.2%) and Bonsmara (81.0%). There was a lower fertilization rate following IVF with Bonsmara and Nguni bull sperm. In conclusion, Nguni cows had similar oestrous response as Bonsmara cows. The sperm traits from Bonsmara and Nguni bulls were found to be related to in vivo conception and in vitro fertilization rate when sperm cells were assessed by CASA technology. However, the pregnancy rate was lower in Nguni cows.

145 THE ROLE OF CELL APOPTOSIS ON IN VITRO-PRODUCED BEEF CATTLE EMBRYOS

Successful in vitro development of embryos is dependent upon maintenance of cellular function in the embryonic microenvironment. Exposure of pre-implantation embryos to a variety of cellular stresses can induce apoptosis in all or a fraction of blastomeres. Among the conditions that can induce apoptosis in cattle embryo production in vitro are heat shock, media composition, oxygen levels, and tumour necrosis factor (TNF)-α. The aim of the study was therefore to evaluate the in vitro culture environment of embryos in terms of cell apoptosis through caspase and DNA fragmentation evaluation. A total of 1200 immature oocytes were collected at slaughter from indigenous South African cow ovaries. The cumulus-oocyte complexes were randomly allocated into 2 maturation temperatures, 39°C and 41°C (200/temperature /replicated 6 times), and cultured in M199 + FSH-LH-oestradiol medium under oil at 100% humidity and 5% CO2 for 24 h. Postmaturation, oocytes were subjected to normal subsequent embryo conditions (Rynkowska et al. 2011 Biotechnol. Comput. Biol. Bionanotechnol. 92, 45–53). All matured oocytes were fertilized for 6 h with frozen-thawed Nguni bull semen from 10 bulls replicated 5 times at a concentration of 265 × 106 sperm cells/mL in Bracket and Oliphant medium under oil. The presumptive zygotes from each treatment were cultured into SOF-BSA medium under oil and incubated at 39°C for assessment of cleavage rate post IVF. Produced embryos were divided into 3 groups: 2–4 cell, ≥8 cell embryos, and blastocyst. Two- to four-cell embryos were removed at Day 2, ≥8 cell at Day 5 (mainly 8-cell, morula, and cavitated blastocyst), and expanded blastocyst at Day 7 of embryo culture to determine caspase activity and DNA fragmentation for evidence of apoptosis. Caspase was performed using colourimetric assay on a 96-well microplate reader and monitored at 450 nm reference filter. The DNA fragmentation was examined using the TUNEL assay method and imaging was done using the Alexa Fluor® 488 emission at 519 nm. Data were analysed using SAS 9.2 software (SAS Institute Inc., Cary, NC, USA), and Shapiro-Wilks test was used on the standardized residuals to test for deviations from normality, means of significant effects were compared using Student’s t-l.s.d. at the 95% confidence interval. There was no significant difference on the cleavage rates [39°C (72.0 ± 22.70) and 41°C (67.2 ± 18.9)] and blastocysts [39°C (11.4 ± 2.6) and 41°C (11.2 ± 6.3)] from both maturation temperatures. Caspase activity showed no significant difference on 2–4 cell [39°C (0.015 ± 0.001) and 41°C (0.016 ± 0.002)] and ≥8 cell embryos at both temperatures [39°C (0.022 ± 0.007a) and 41°C (0.032 ± 0.013)]. However, blastocyst differed significantly at both temperatures [39°C (0.037 ± 0.012) and 41°C (0.053 ± 0.005)]. A higher (P < 0.05) DNA fragmentation was observed at 2–4 cell (6.5 ± 2.9), ≥8 cell (13.3 ± 3.1), and blastocyst (48.0 ± 8.2) for embryos produced from 41°C matured oocytes compared to the 39°C maturation group [2–4 cell (2.2 ± 1.2), ≥8 cell (4.5 ± 1.9), and blastocyst (9.7 ± 6.7)]. It is therefore concluded that embryos produced from 41°C matured oocytes can have the same developmental capacity as the 39°C maturation group. Moreover, both temperatures can show signs of apoptosis, however, with more apoptosis evidence in the 41°C than the 39°C maturation group.

Comparison of four different permitting and combination of two best cryoprotectants on freezing Nguni sperm evaluated with the aid of computer aided sperm analysis

Cryopreservation has been reported to damage approximately 40–50% of viable sperm in bull semen. The present study was undertaken to assess the cryo-effectiveness of glycerol (GLY), ethylene glycol (EG), dimethyl sulfoxide (DMSO) and propylene glycol (PND) as cryoprotectant during the cryopreservation of Nguni bull semen. Semen was collected from 18 Nguni bulls and evaluated macroscopically and microscopically for sperm parameters. Thereafter, the semen samples were diluted with egg-yolk citrate extender supplemented with either 12% GLY or DMSO or EG or PND cryoprotectant. Semen samples were loaded into straws and placed into a controlled rate programmable freezer and stored in a liquid nitrogen tank. Following semen thawing, artificial insemination (AI) was done on synchronized Nguni cows. The in vitro fertilization (IVF) was conducted on cow's oocytes to test the fertilizing ability. Data was analyzed with the aid of ANOVA. A significant difference (p < 0.05) was recorded between fresh total sperm motility rate (94.7 ± 2.6%) and frozen-thawed sperm total motility rate with GLY (77.8 ± 11.0%), EG (20.4 ± 10.1%), DMSO (15.7 ± 11.9%) and PND (11.2 ± 11.3%). Interestingly, a positive correlation between total sperm motility and pregnancy rate (r = 0.42) was recorded. However, a negative correlation of Nguni sperm parameters with IVF (r = −0.53) was obtained. The freezing-thawing process did reduce the Nguni sperm total sperm motility percentage.

37 DOUBLE FREEZING AND THAWING OF NGUNI BULL SEMEN

Indigenous bulls semen are important for conservation programs. The objectives of this study were to evaluate the effects of repeated freezing and thawing on sperm motility characteristics. Semen was collected from 4 Nguni bulls by means of electro ejaculator and stored in a thermo flask (37°C). Sperm total motility, progressive and nonprogressive motility, and velocity were assessed using computer-aided sperm analysis before and after freezing. Semen was then diluted with egg yolk citrate extender (fraction A), then followed by 12% of glycerol + egg yolk citrate extender (fraction B, Seshoka et al. 2012). Diluted semen samples were equilibrated for 4 h at 5°C. After the equilibration period, samples were loaded into 0.25-mL straws and transferred into a controlled rate programmable freezer. After the target temperature of –130°C was reached, semen straws were stored in a LN tank (–196°C). After 3 months of storage, straws were thawed at 15°C (first and second freezing and thawing followed the same process) for 5 min and further evaluated post-thawed at 0 and 15 min during incubation at 15°C. Treatment means were separated using Fisher’s protected t-test least. No significant differences were recorded between the raw semen total sperm motility percentage (93.2%) and first frozen-thawed at 0 min (82.6%), with the total sperm motility rate recovery of 88.6%. In addition, there was a marked decline recorded in sperm total motility during the first frozen-thawed at 15 min (77.6%), second frozen-thawed at 0 min (31.3%), and second frozen-thawed at 15 min (30.1%; P &lt; 0.05). The sperm curvilinear velocity and average path velocity was reduced following first frozen-thawed (P &lt; 0.05) but remained constant and stable between the treatment groups (P &gt; 0.05). In conclusion, the freezing-thawing process did not reduce the Nguni bull total sperm motility during the first freezing and thawing process, compared with raw semen. However, a drastic decline was recorded during the second freezing-thawing processes, compared with raw semen.

38 QUAIL EGG YOLK IN CITRATE EXTENDER IS SUITABLE FOR CRYOPRESERVATION OF NGUNI BULL SEMEN

Traditionally, commercial hen egg yolk has been used in extenders or freezing media because of its easy availability. However, the use of quail egg yolk has not been used for preserving Nguni bull semen. The aim of the study was to compare the suitability of different quail egg yolk concentrations (5, 10, 15, and 20%) for cryopreserving Nguni bull semen. Semen was collected from 14 stud Nguni bulls with the aid of electro ejaculator. Collected semen samples were kept in a thermos-flask containing warm water at a temperature of 37°C and transported to the laboratory for further analyses. The sperm motility traits were evaluated using computer-aided sperm analysis prior extension. Semen samples were then randomly allocated into 5, 10, 15, and 20% of quail egg yolk and 20% concentration of chicken egg yolk (control) in citrate extender. The extender was supplemented with 12% of glycerol (Seshoka et al. 2012) as a cryoprotectant, and semen samples were diluted (1 : 2) and equilibrated for a period of 4 h at 5°C. After equilibration, semen samples were loaded into 0.25-mL straws, placed into a controlled rate programmable freezer, and stored in a LN tank (–196°C) until thawing. Frozen semen straws were thawed in a water bath at 37°C for 1 min. Thawed semen was evaluated for sperm motility traits using a computer-aided sperm analysis system. Data were analysed with ANOVA. A significant difference was recorded between fresh total sperm motility rate (99%) and frozen-thawed semen samples with either 5% (87.3%) quail or 20% (87.6%) chicken egg yolk citrate extender compared with 10% (92.6%), 15% (91.2%), or 20% (89.9%) quail egg yolk citrate extender. Moreover, fresh semen also resulted in a significantly higher progressive sperm motility rate (39.3%) as compared with frozen-thawed with 5% (26.2%) or 20% quail (28.5%) or 20% chicken (22.7%) egg yolk citrate extender. The results also demonstrated that the use of 10, 15, and 20% quail egg yolk in citrate extender yielded comparable results on total sperm motility with fresh semen as compared with 5% quail and 20% chicken egg yolk. In conclusion, quail egg yolk extender provided sufficient cryo-effectiveness to cryopreservation of Nguni bull semen.

158 IMPACT OF MATURED CATTLE OOCYTES AT HIGHER INCUBATION TEMPERATURE ON IN VITRO EMBRYO PRODUCTION

Heat stress during IVF is associated with reduced fertility in cattle oocytes. It may, however, enhance thermo-tolerance or cause detrimental effects on a variety of cell types or organisms, depending on the duration and intensity of the thermal challenge. The aim of this study was to evaluate the developmental potential of cumulus-oocyte complexes (COC) matured for 18 or 24 h and incubated at 39°C or 41°C. A total of 1000 immature oocytes were collected at slaughter from indigenous South African cow ovaries. The COC were randomly allocated (100/treatment) into 2 maturation times (18 or 24 h) and cultured in M199 + FSH-LH-estradiol medium under oil at 100% humidity and 5% CO2 at 39°C or 41°C. Post maturation, oocytes were subjected to normal subsequent embryo conditions. The Bracket and Oliphant medium was used for IVF. All matured oocytes were fertilised for 6 h with frozen-thawed Nguni bull semen at a concentration of 265 × 106. The presumptive zygotes from each treatment were cultured into SOF-BSA medium under oil and incubated at 39°C for assessment of cleavage rate 48 h post IVF. After Day 7 of culture, blastocyst were stained (Hoechst 33323) for nuclei cell count. Statistical analyses was performed using Genstat® software of SAS (SAS Institute, Cary, NC, USA; P &lt; 0.05). Oocytes that were matured for 18 h in 41°C resulted in more 8-cell embryos (41%) compared with those incubated at 39°C (21.6%). However, no difference was observed for cleavage rate at both maturation times and incubation temperatures (41 or 39°C). There was more morula formation from oocytes matured for 18 h (19.6%) and 24 h (19.0%) at 41°C compared to 39°C (8.4%) group. The results further showed more blastocyst formation during 18 h at 41°C (15.2%) than at 39°C (7.4%) and during 24 h at 41°C (11.2%), 39°C (11.4%). However there was no difference in the nuclei cell number during 18 h at 41°C (45.2), 24 h (45.8), and 18 h at 39°C (43.4) of maturation. Thus, there was a significant difference in the nuclei cell numbers at 24 h on 39°C (n = 133.2) and 41°C (n = 45.8). In conclusion, oocytes that were matured for 18 and 24 h at 41°C or for 18 h at 39°C developed further to blastocyst stage on in vitro embryo production, however, with low nuclei cell numbers due to accelerated maturation temperature or shortened maturation period.

8 RESPONSE OF COMMUNAL COWS TO OESTRUS SYNCHRONIZATION AND TIMED ARTIFICIAL INSEMINATION

Reproductive technologies such as oestrus synchronization and AI have been tested in controlled environments in the commercial farms in South Africa but not in an uncontrolled communal setup. The aims of the study were to evaluate the response of communal cows to oestrus synchronization and timed AI. The effects of age and body condition score (BCS) on oestrus response and conception rate were also studied. A total of 96 cows were selected from the communal villages. Cows with the BCS of 2.5 to 4.5 (on a scale of 1–5) and age between 3 and 10 years were used. Cows were grouped into 2 BCS groups (&lt;3 and = 3) and 2 age groups (&lt;6 and = 6). All groups were subjected to a 9-day Ovsynch + CIDR (CIDR®; Pfizer Laboratories, New York, NY, USA) protocol. A CIDR® was inserted into the vagina on Day 0 (random days of the cycle), and 2 mg of oestradiol benzoate (Ciderol®; Pfizer Laboratories) was administered. On Day 8, the CIDR® was removed, and the cows were administered with 500 μg of cloprostenol (PGF; Estrumate®, Schering-Plough Animal Health). In addition, on Day 9, cows were given 1 mg of oestradiol benzoate, and a heat mount detector (Karma®; Four Lakes) was placed on the tail head of the cows to detect oestrus response (standing heat). All the synchronized cows were then inseminated at 36 and 42 h with frozen-thawed Nguni bull semen following oestradiol benzoate injection. Pregnancy diagnosis was performed 90 days following timed AI using ultrasound scanner and transrectal palpation. Data were analysed using ANOVA. An overall 73% oestrus response and 45% conception rate were achieved in this study. There was no significant difference in oestrus response in cows with a BCS &lt;3 (67%) and = 3 (83%) or age &lt;6 (77%) and = 6 (72%). There was no significant difference in conception rate between those &lt;6 (41%) and = 6 (47%) years of age. However, cows with a BCS of = 3 had greater (P &lt; 0.05) conception rate (55%) compared with those with a BCS &lt;3 (35%). In conclusion, communal cows responded to an oestrus synchronization program involving timed AI. The BCS and age did not alter the oestrus response, but conception rate was higher in communal cows with BCS of = 3.

53 COMPARISON OF 4 DIFFERENT CRYOPROTECTANTS ON FREEZING NGUNI BULL SPERMATOZOA EVALUATED BY COMPUTER-AIDED SPERM ANALYSIS

Cryopreservation has been reported to damage approximately 40 to 50% of viable spermatozoa in bulls. It is critical to evaluate frozen-thawed spermatozoa with computer-aided sperm analysis (CASA) and find a suitable cryoprotectant for Nguni semen. The study was conducted to compare cryo-effectiveness of glycerol (GLY), dimethyl sulfoxide (DMSO), propanediol (PND), and ethylene glycol (EG) cryoprotectants at 12% concentrations during freezing of Nguni bull semen. Semen was collected from 18 stud Nguni bulls of proven fertility with the use of an electro-ejaculator. Collected semen samples were kept in a thermo flask (37°C) and transported to the laboratories. Semen samples were pooled and sperm motility rate was evaluated using CASA. Semen was then diluted (1 : 2; vol : vol) with egg-yolk citrate extender supplemented with either 12% GLY, DMSO, PND, or EG. Semen samples were equilibrated for 4 h at 5°C. After equilibration, samples were loaded into 0.25-mL straws and placed into the controlled rate programmable freezer using a customized freezing curve (from 5 to –5°C at 0.008°C min–1 and from –3 to – 130°C at 6°C min–1). Following thawing of semen, artificial insemination was conducted on 104 oestrus-synchronised Nguni cows. The IVF was also conducted on 120 oocytes to check the cleavage rate. Data were analysed using ANOVA. There was a significant difference (P &lt; 0.05) between raw total sperm motility (94.70 ± 2.63) and frozen-thawed sperm total motility with GLY (77.80 ± 11.03), EG (20.35 ± 11.86), DMSO (15.68 ± 10.14), and PND (11.19 ± 11.27) groups. The pregnancy rate following artificial insemination was 75.9% and a total of 86.6% oocytes had cleaved after fertilization with frozen (12% GLY)/thawed semen. In conclusion, cryopreservation process reduced sperm motility and velocity rates, regardless of cryoprotectant. Egg-yolk citrate extender supplemented with 12% glycerol had recorded the highest post-thaw sperm motility rate.

76 THE EFFECT OF GLYCEROL CONCENTRATIONS IN EGG-YOLK CITRATE EXTENDER ON THE QUALITY OF CRYOPRESERVED NGUNI BULL SEMEN

There are bull shortages in South African poor rural areas. Artificial-insemination technology could play a significant role on breeding emerging farmer’s cattle. The objective of this study was to compare glycerol concentrations (0, 4, 8, or 12%) during freezing of Nguni bull semen to conduct AI in different villages. Semen was collected by electro ejaculator from 2 Nguni bulls of known and proven fertility. Collected semen samples were kept in a thermo flask (37°C) and transported to the laboratories within 10 min after collections. Semen samples were pooled and evaluated by Sperm Class Analyser® and allocated randomly per treatment. Semen was then diluted (1 : 2 v:v) with egg-yolk citrate extender supplemented with either 0% (negative control), 4, 8, and 12% of glycerol concentration or AndroMed® (positive control). Semen samples were equilibrated for 4 h at 5°C. After equilibration period, samples were loaded into 0.5-mL straws and placed horizontally into the controlled rate (–5, –8, –10, –12, –15, –25, –35°C min–1) from 5°C until target temperature of –80°C is reached. The frozen semen straws were stored in a liquid nitrogen tank (–196°C) until thawing. Treatment means were separated using Fisher’s protected t-test least, and data are presented as mean ± SD. There was a significant differences (P &lt; 0.05) between raw total sperm motility (83.3 ± 19.3) and frozen–thawed sperm with either 0% (0.0 ± 0.0), 4% (30.2 ± 13.4), 8% (47.9 ± 12.5), or 12% (61.5 ± 4.7) of glycerol and on AndroMed® (27.7 ± 17.8) group. Regardless of the glycerol concentrations used, the freezing-thawing process reduced (P &lt; 0.05) the Nguni total sperm motility rate compared to uncryopreserved sperm (83.3 ± 19.3). In conclusion, egg-yolk citrate extender supplemented with 12% glycerol yielded a better (P &lt; 0.05) total sperm motility rate (61.5 ± 4.7) as compared with the 0% (0.0 ± 0.0), 4% (30.2 ± 13.4), 8% (47.9 ± 12.5), and AndroMed® (27.7 ± 17.8) group. Further studies are required to test other levels of glycerol concentrations (&gt;12%) on freezing Nguni semen and conducting AI.

107 MOTILITY PARAMETER PATTERNS OF NGUNI BULLS: EFFECT OF VARIOUS GYCEROL CONCENTRATIONS FOLLOWING CRYOPRESERVATION

The Nguni breed of South Africa is small, hardy, disease-tolerant, thrives on poor pasture, and was regarded as an inferior breed in the past. For optimizing routine fresh and freezing of Nguni bull semen analysis, 3 different concentrations of glycerol (7, 10, and 14%) were examined. Ten ejaculates were collected from each 6 Nguni bulls using electro-ejaculator at ARC, Irene, South Africa. Following semen collection, semen was examined for macroscopic (volume, pH, and concentration) and microscopic (motility) parameters. The semen was extended with Tris + 10% egg yolk diluent at a ratio of 1 : 2 (v/v) and frozen at different concentrations of glycerol (7, 10, and 14%). The semen was then evaluated using the sperm class analyzer (SCA; CASA system) for progressive motility parameters. Fresh and frozen-thawed were fixed and stained with Nigrosin-Eosin for morphology (dead and live). Data were analyzed by ANOVA. There was a significant difference among individual Nguni bull spermatozoa volume and concentration. Analyzed frozen-thawed Nguni spermatozoa resulted in a significant (P &lt; 0.05) difference of spermatozoa motility parameters frozen in 10% glycerol (68%) compared with 7 (41%) and 14% glycerol (30%). In conclusion, Nguni spermatozoa can be cryopreserved successfully when 10% of glycerol concentration is used. The results of this study will improve the viability of cryopreserved Nguni bull spermatozoa following the development of a South African semen cryo-gene bank. This study was supported by grants from National Research Foundation (NRF), Hungarian, South African Bilateral Scientific and Technological (TETNo. OMFB-00302/2008, RT24000) collaborative project. Department of Agriculture Forestry and Fisheries (DAFF, RPPP15).