Influence of breeding season on fecal glucocorticoid levels in captive Greater Rhea (Rhea americana).

Sex hormones and stress-related changes can be seasonally influenced. We investigate whether fecal glucocorticoid metabolite (FGM) levels can differ between male and female captive Greater Rheas during the breeding and non-breeding seasons. Over a 3-year-period, fresh fecal samples from 10 individuals (five of each sex) were collected during the breeding months (October, November, and December) and non-breeding months (April and June). A total of 960 samples were assayed using a commercial radioimmunoassay. Results showed that FGM levels (mean ± SE) were affected by the breeding season in a sex-dependent way. Male Greater Rheas showed significantly higher FGM levels in the breeding months than in the non-breeding months (13.44 ± 0.37 vs. 7.92 ± 0.1 ng/g feces, respectively). By contrast, females did not show FGM seasonal changes throughout the same sampling periods (7.55 ± 0.14 vs. 7.26 ± 0.73 ng/g feces). Moreover, during the breeding season months, males showed higher average FGM levels than females (13.44 ± 0.37 vs. 7.55 ± 0.14 ng/g feces, respectively), and no differences were found between sexes during the non-breeding season (7.92 ± 0.1 vs. 7.26 ± 0.73 ng/g feces, respectively). Our findings suggest that male Greater Rheas have a higher adrenocortical activity during the breeding season, which is probably indirectly related to the increased testosterone levels and agonist interactions that are also observed during that phase. Studies aimed to determine the appropriate sex ratio for captive rearing should be developed to minimize male agonist encounters and therefore improve welfare of the captive group.

The influence of diet composition on egg and chick traits in captive Greater Rhea females.

1. This study was conducted to evaluate the influence of diet composition on egg number, physical and chemical characteristics of eggs and weight and survival of chicks throughout a breeding season in a captive-bred population of greater rheas (Rhea americana). 2. From August to December, individuals were offered two diets: processed feed for rheas and processed feed for chicken (which is the feed most commonly offered to farmed rheas in Argentina). Reproductive performance of 15 females was monitored and female body weight was recorded before egg-laying onset. Within each experimental group, the following variables were determined: egg morphometric variables and percentage of components, fatty acid composition, hatching success and initial weight of chicks and mortality during the first week of life. 3. Females that were fed on processed feed for rheas delayed onset of laying and reduced laying period and number of eggs produced. However, females of this group laid larger eggs, with higher percentages of yolk and yolk lipids, and exhibited higher hatching success and chick weight compared with those that received chicken diet. Survivorship of chicks in their first week of life was not affected by composition of the diet offered to parental female. 4. Some reproductive parameters of captive greater rhea females fed on processed feed for rheas were higher than those of individuals receiving processed feed for chicken.

Behavioral responses to short-term transport in male and female Greater Rheas (Rhea americana) reared in captivity.

Animal transport is an indispensable practice in species that need to be moved for management or commercial purposes. However, transport may have negative effects on individuals' welfare. The aims of the present work were to determine if the behavioral responses of adult Greater Rheas (Rhea americana) bred in captivity are sensitive to short-term transport and if males and females differ in their posttransport behavioral activity and recovery. Eight males and 8 females were placed in individual pens and allowed 6 d to habituate (d 1 to 6) before transport procedure. On the transport day (d 7), half of the birds (4 males and 4 females) were randomly assigned to a transport group that was captured and handled to be placed into the crates, exposed to a 30-min transport stressor, and immediately returned to their pens. Four transports with 1 different male and female each time were performed. The other half remained undisturbed and were used as controls. Behavior of all individuals was video-recorded during habituation days, after transport on d 7, and on the 2 following days (d 8 and 9) to evaluate pre- and posttransport behavioral activity for 2 h per day. No significant behavioral changes were observed during the last 2 d of the habituation period (d 5 and 6), suggesting that Greater Rheas were adapted to the housing conditions before transport. After transportation, several behaviors were affected: transported males and females showed null resting, transported females also showed reduced preening and increased vigilance (P < 0.05), whereas transported males showed increased drinking (P < 0.05) compared with their respective control groups. The results suggest that behavioral responses of captive-bred Greater Rheas are sensitive to short-term transport (which includes handling) and that males and females differ in their posttransport behavioral activity, recovering their overall basal levels on the third day posttransportation.

Corticosterone stress response of Greater Rhea (Rhea americana) during short-term road transport.

The effect of transport stress on blood corticosterone levels in captive Greater Rheas was investigated. Twelve adult individuals (7 males; 5 females) were loaded in pairs inside wooden crates and transported along a paved road for 30 min. Blood samples were taken before the individuals were introduced into the crate (baseline value) and immediately after they were unloaded (30 min after capture). To assess whether corticosterone levels were affected by the blood sampling procedure per se, another 6 (nontransport) control birds (3 males; 3 females) were also captured and sampled at the same times as their transported counterparts. Plasma corticosterone concentrations were measured using a commercially available corticosterone (125)I radio-immunoassay kit. Baseline corticosterone levels were similar in the control and transported birds (9.0 ± 1.6 and 10.4 ± 0.8 ng/mL, respectively). Transportation induced a highly significant (P < 0.001), more than 40-fold increase in the corticosterone levels (433.6 ± 35.4 ng/mL) that was about 5 times higher (P < 0.001) than in their nontransported counterparts (88.4 ± 14.8 ng/mL). The present findings suggest that Greater Rhea is a species highly sensitive to stressful manipulations. Both blood sampling and transportation induced highly significant adrenocortical responses. Considering that transportation is one of the unavoidable common practices in the management of Greater Rheas and, as shown in the present study, that it induces a significant 40-fold corticosterone stress response, efforts should focus on helping to generate management transport standards for optimization of the welfare of this ratite.

Efficiency of the cloacal sexing technique in greater rhea chicks (Rhea americana).

1. The feasibility and accuracy of the cloacal sexing technique in greater rhea chicks was assessed using chicks of two captive populations of greater rhea in Córdoba, Argentina. 2. A total of 46 greater rhea chicks of 2 to 3 months of age were randomly arranged into three groups and the members of each group were sexed by a different operator. 3. A feather of each chick was plucked for sexing through a molecular method and results were used as controls. 4. Sex was correctly assigned by cloacal inspection in 98% of the cases. Chick manipulation was easily performed and no infections or traumatic lesions were observed a posteriori. 5. Cloacal sexing of rhea chicks up to 3 months of age does not affect animal welfare and should be considered an efficient alternative to molecular methods.

May captive populations of Greater Rhea (Rhea americana) act as genetic reservoirs in Argentina?

The Greater Rhea (Rhea americana) is a characteristic bird of the Argentine Pampas. Despite the increasing farming interest of this ratite, their natural populations are progressively decreasing in size and range. The object of this study was to evaluate the status of captive populations as potential genetic reservoirs. Using Inter-Simple Sequence Repeats as molecular markers, levels of genetic variability of F1 individuals from two captive populations were estimated and compared with those of wild populations in the same region. The captive populations were polymorphic for 12.22 and 13.33% of the loci, with a genetic diversity of 0.050. Differences with wild populations were not significant (z=1.79; P>0.05). Therefore, captive populations of rheas in Argentina should not be overlooked as genetic reservoir and source of individuals for reinforcement of natural populations, through reintroduction and translocation.

Effect of age and body weight of Greater Rhea (Rhea americana) females on egg number, size and composition.

1. A study was conducted to evaluate how body weight and age of each female are related to the number and physical and chemical characteristics of the eggs produced throughout a breeding season in a captive-bred population of Greater Rheas (Rhea americana). 2. Reproductive performance of 15 females of three age classes (5 individuals per class) was monitored; female body weight was recorded before laying-onset. All the eggs laid were collected and identified, and different morphometric variables, percentage of components and fatty acid composition were determined. 3. The earlier the female started egg-laying, the longer the laying period and the greater the overall number of eggs produced. The onset of egg-laying in turn seemed to be related to the attainment of a high body weight. 4. Except for length, the values of the morphometric variables of the egg and unsaturated fatty acids (palmitoleic, oleic and linoleic) increased with female age. 5. High body weight was associated with low palmitic and palmitoleic fatty acids and high linoleic, linolenic and total unsaturated fatty acids. 6. Live weight and age of females can determine several physical and chemical characteristics of eggs.

Coefficients for the estimation of fresh weight and volume of Greater Rhea eggs.

1. Specific values of constants needed to estimate fresh weight (Kw) and volume (Kv) of Greater Rhea eggs were obtained. 2. The average value for the weight coefficient (Kw) was 0.57, whereas that for volume (Kv) was 0.51. Accuracy of results obtained with these values was +/-2.1% and +/-3.5%, respectively. 3. The fresh weight and volume of Greater Rhea eggs can be easily estimated by means of these specific coefficients when those measurements cannot be taken directly.

DNA test to sex the lesser rhea (Rhea pennata pennata).

1. A polymerase-chain-reaction (PCR)-based test was adapted to sex the lesser rhea. Feathers instead of blood were used as the source of DNA. 2. The primers used allowed the assignment of sex by amplification of Z and W chromosome linked sequences. 3. This method proved to be safe, accurate and non-invasive. 4. The W chromosome linked fragment was sequenced and compared to other ratite sequences.

Rearing greater rhea (Rhea americana) chicks: is adoption more effective than the artificial intensive system?

(1) Survival and weight gain of farmed Greater Rhea (Rhea americana) chicks reared by the adult males that adopted them were compared with those of chicks reared under an artificial intensive system. (2) Both variables were periodically recorded up to the age of 3 months. Gompertz growth curves were fitted to individual growth data using the average adult weight of this population as asymptote. (3) No significant differences in survival rate were detected between systems (adoption=47%, intensive=43%). However, during the first half of the breeding season (mid-spring to mid-summer), the growth rate of adopted chicks (0.01481) was higher than that of intensively reared chicks (0.01296). (4) The adoption system may be more effective in terms of growth, and is probably more efficient in cost/effectiveness than the artificial intensive technique most frequently used. Adoption by males has additional advantages, such as a correct imprinting of the chicks and the selection of more capable individuals. Therefore, it should be used not only commercially but also in conservation projects where individuals are released to the wild.

Pharmacokinetics of enrofloxacin following intravenous administration to greater rheas: a preliminary study.

The pharmacokinetic behaviour of enrofloxacin (ENR) and its active metabolite ciprofloxacin (CIP) were determined in six greater rheas following a single intravenous (i.v.) dose of 15 mg/kg bw. Plasma concentrations of ENR and CIP were simultaneously determined by a HPLC/u.v. method. Following i.v. administration, the plasma drug concentrations were best fitted by an open two-compartment model with a rapid distribution phase. The high volume of distribution (V(ss)=5.01 L/Kg) suggests good tissue penetration. ENR presents a high clearance (3.95 L/kg h) explaining the low AUC values (3.57 mg h/L) and a short permanence (t(1/2beta)=2.66 h and MRT=1.23 h). Ciprofloxacin comprised 14% of the total fluoroquinolone (ENR+CIP).

Effects of storage time on hatchability of artificially incubated Greater Rhea (Rhea americana) eggs.

(1) A study was conducted to determine the effects of the length of the storage period on the hatchability of artificially incubated Greater Rhea eggs. Hatchability was evaluated in eggs gathered daily from a captive population and in eggs collected less frequently from a semi-captive population. (2) Eggs form both sites were either immediately incubated after being collected or were stored for 1 to 9 d prior to incubation. (3) The maximum number of days for which an egg could be stored without depressing hatchability (with respect to non-stored eggs) was longer in the eggs collected daily. (4) Eggs collected daily and stored for 4d or more showed total hatchability (28%) and fertile hatchability (43%) which was approximately 30% lower than non-stored eggs or eggs stored for 3 d or less. In the semi-captive population, the total and fertile hatchability of non-stored eggs and of eggs stored for one day were 40% greater than of eggs stored for 2 to 9 d (20 and 34%, respectively). (5) The period for which Greater Rhea eggs could be stored without depressing hatchability varied depending on the frequency of egg collection: non-daily egg collection reduces the possible period of storage.

Physical characteristics and chemical composition of Lesser Rhea (Pterocnemia pennata) eggs from farmed populations.

1. Eggs from 4 farmed populations of Lesser Rhea (Pterocnemia pennata) were studied to determine their physical and chemical characteristics. 2. None of the physical variables (weight of whole egg, yolk, albumen and shell; proportion of yolk based on egg content; proportion of shell based on entire egg weight; volume; density) showed significant differences between populations. 3. Among chemical variables, moisture, both saturated fatty acids (palmitic 16:0 and stearic 18:0), one monounsaturated fatty acid (palmitoleic 16:1), and one polyunsaturated fatty acid (arachidonic 20:4), did not differ between populations, whereas other variables (protein, lipid and ash contents; fatty acids: oleic 18:1, linoleic 18:2, linolenic 18:3; PUFA; PUFA/SFA; cholesterol) differed significantly.

Microbial contamination of artificially incubated Greater Rhea (Rhea americana) eggs.

1. This paper is a report of biological agents that contaminate Greater Rhea (Rhea americana) eggs during artificial incubation. 2. The cleanliness of eggs when collected, and the period of storage prior to incubation, were investigated to assess their effects on microbial contamination and hatchability. 3. A total of 14 bacteria and 4 fungi species were isolated within the egg in the laboratory. 4. Microbial contamination was higher (24%) in very dirty eggs than in eggs which were clean or dirty (16%). Hatching success was lower (30%) for very dirty eggs, compared with 42% for clean or dirty eggs. 5. The percentage of microbial contamination of stored eggs (10%) did not differ significantly from that of non-stored ones (5%). 6. The extreme lower and upper limits of infection rate estimated for artificially incubated Greater Rhea eggs were 4% and 40%, respectively, being higher than in poultry species. 7. It is concluded that collecting eggs soon after laying will reduce the risk of microbial contamination.

Long-term follow-up of Greenfield inferior vena cava filter placement in children.

OBJECTIVE: The long-term results of Greenfield inferior vena cava (IVC) filter placement have been well documented in adults; however, similar data do not exist for pediatric patients. The potential for growth and the increased life expectancy in younger patients may contribute to a difference in the natural history of filters placed in children. The objective of this study was to evaluate the long-term outcome of pediatric patients with IVC filters. METHODS: At the University of Massachusetts Memorial Medical Center, medical records and radiographs of patients 18 years old or younger at the time of IVC filter placement were reviewed. Follow-up data were obtained by interview, physical examination, and venous duplex ultrasound scanning. RESULTS: A total of 15 IVC filters were placed in children 18 years old or younger between 1983 and 1999. In 10 patients the indications for IVC filter placement were lower-extremity deep venous thrombosis (DVT) and/or pulmonary embolism. In five patients, prophylactic filters were placed in the absence of DVT because of a high risk for the development of pulmonary embolism. Surgical exposure of the right internal jugular vein was used to place the first eight filters. The remainder were inserted percutaneously through the right internal jugular vein or the right common femoral vein. There were no complications or mortality related to filter insertion. Follow-up of the surviving 14 patients ranged from 19 months to 16 years. During long-term follow-up, no patient had a pulmonary embolus. Of the nine patients who had lower-extremity DVT, three developed mild common femoral venous reflux documented by duplex scan. Of the five patients who had prophylactic filters, four had no symptoms or duplex evidence of reflux. The other patient, who was paraplegic, had bilateral leg edema but no venous varicosities and no reflux on duplex scan 11 years after filter placement. No patient in either group had chronic venous obstruction. CONCLUSION: In long-term follow-up there were no instances of pulmonary embolism, IVC thrombosis, significant postphlebitic symptoms, or significant filter migration among 14 pediatric patients with Greenfield IVC filters. This suggests a safety profile and efficacy similar to that seen in adults.

Cholesterol content and fatty acid composition of rhea meat.

The influence of species and muscle on the intramuscular fat content, cholesterol content and fatty acid composition of Greater and Lesser Rhea meat were evaluated. Muscle has no influence (P>0.05) on any of these characteristics. Neither intramuscular fat (1.23%) nor cholesterol content (57 mg/100 g) differed (P>0.05) between species. Despite differences (P<0.05) in the percentage of individual fatty acids, total saturated fatty acids (33.1%) did not differ (P>0.05) between species, while total monounsaturated fatty acids (26.8 vs 32.2%) was lower (P<0.05) and total polyunsaturated fatty acids (39.7 vs 33.6%) higher (P<0.05) for Greater than Lesser Rhea.

Carcase and component yields of rheas.

1. Three Greater Rheas (Rhea americana) and 5 Lesser Rheas (Pterocnemia pennata) were slaughtered, using the procedures conventional for ostriches in South Africa, in order to determine the expected yield of by-products and saleable lean meat, fat and bone of rheas. 2. Differences (P < 0.05) between species were found in the proportional weight of the wings, feet, skin and liver. The wings, feet and head of rheas form a higher proportion of the carcase than in ostriches, whereas the skin of the former represents a lower percentage of body weight. 3. Lean meat production from rheas (64% on a carcase weight basis) is in the same order as for ostriches, broilers, turkeys and beef.