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.     

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.     

Observations on helminth infections of free-living and captive rheas (Rhea americana) in Brazil

The present work describes helminth infection of eight free-living and 12 captive rheas (Rhea americana) from, respectively, Pantanal of Mato Grosso do Sul State, and Jaboticabal, Sao Paulo State, Brazil. Captive birds were young and had a high mortality rate, while free-living birds were adult and apparently healthy. Infections were evaluated by post-mortem examination of internal organs and recovery of helminths using standard parasitological procedures. Seven species of nematodes (Sicarius uncinipenis, Torquatoides crotophaga, Deletrocephalus dimidiatus, D. cesarpintoi, Paradeletrocephalus minor, Capillaria venteli and Dicheilonema rheae) and two species of cestodes (Houttuynia struthionis and Chapmania tauricolis) were identified. P. minor, which inhabits the large intestine, was the most common helminth in free-living birds (63.9%). In captive rheas, a mean parasitic load of 173 helminths per host was found. The gizzard of these birds was the most parasitized organ and S. uncinipenis was most common (92.5%). Parasitism of free-living and captive birds and associated pathology are discussed.     

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.     

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.     

A comparison of reproductive parameters of female Amur tigers (Panthera tigris altaica) in the wild and captivity

A healthy population of captive Amur tigers might assist recovery of the wild population in Northeast China if individuals were properly prepared and considered suitable for release in the wild. We analyzed the breeding records of 68 female Amur tigers from 1995 to 2010 in the Hengdaohezi Felid Breeding Center of China and compared the reproductive parameters of this population to wild female Amur tigers. We found that the reproductive parameters of the captive population (the age of first parturition, length of gestation and litter survival rate) were not significantly different from those of wild Amur tigers. Differences in birth date and litter size between wild and captive populations may be caused by management protocols for the captive population or insufficient field data from the wild population. Reproductive parameters of females giving birth after losing a litter were similar to parameters of females that did not lose a litter, except for birth date. These results provide no indication of major problems in using captive females for a breeding program for release of cubs into the wild, but additional information is still needed to assess their suitability.     

Ontogenetic Scaling of the Hindlimb Muscles of the Greater Rhea (Rhea americana)

The greater rhea (Rhea americana) is the largest South American bird. It is a cursorial, flightless species with long powerful legs and reduced forelimbs. The goal of this study was to explore how hindlimb muscles scale with body mass during postnatal growth and to analyze whether the specialized locomotion of this species affects the growth of muscle masses. The mass of 19 muscles and body mass were weighed in 21 specimens ranging from 1‐month‐old individuals to adults. Seventeen muscles scaled with positive allometry with respect to body mass, whereas two muscles scaled isometrically . The predominance of positive allometric growth in hindlimb muscles results in a limb with massive and powerful muscles specialized to support a large body mass and to attain relatively high running speeds. Analysis of muscle mass scaling is a simple and useful way to compare possible differences between locomotor styles, and it is valuable in studies that reconstruct the paleobiology of extinct taxa.     

Chronic fascioliasis in farmed and wild greater rheas (Rhea americana)

From 50 farmed Rhea americana slaughtered for human consumption, adult forms and eggs of Fasciola hepatica were found in 4. The other three livers were free of flukes but did show lesions caused by larval fluke migration. Histological lesions were similar to those caused by flukes in cattle and sheep. The rheas were from an endemic area of ruminant fascioliasis in Southern Brazil. F. hepatica eggs were also found in faecal samples of wild rheas from another endemic area in Southern Brazil. It is likely that the rheas play a role in the transmission of the disease to ruminants and could be jeopardizing the control of this parasitosis in endemic areas. From the best of our knowledge this is the first report of fascioliasis in R. americana.     

Longitudinal study of northern fur seal (Callorhinus ursinus) hematology

Although the causes have not been specified yet, wild populations of northern fur seals (Callorhinus ursinus) have been decreasing, which is why conservation techniques such as captive breeding and health maintenance should be established. Hematological parameters can be used to maintain the health status of northern fur seals kept in captivity for artificial reproduction and public education. Year-round fluctuations of blood parameters have not been examined for northern fur seals due to the difficulties in obtaining serial blood samples from wild animals during the oceanic migration period from late autumn to spring. In this study, blood samples were collected from four captive northern fur seals and analyzed monthly for more than three years to clarify the seasonal fluctuation patterns in 14 hematological parameters. Many hematological parameters seemed to be seasonal patterns: summer–autumn and winter–spring; leukocyte-related parameters were higher in summer and autumn than in winter and spring; erythrocyte-related parameters were lower in summer and autumn than in winter and spring. Significant seasonal differences in nine of the 14 parameters were observed using a generalized linear mixed model (GLMM) analysis. These results have improved our understanding of the seasonal patterns of hematological characteristics in the northern fur seal and can contribute to the health care of protected or captive northern fur seals.     

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.     

Relationships of the Host,Pathogen, and Environment: Implications for Diseases of Cultured and Wild Fish Populations

Abstract

Many effects of diseases on cultured fish are known; they are less clear in wild fish populations. Cultured fish represent captive populations that can be subjected to intense scrutiny with an increasing range of diverse and powerful tools. Disease represents a spectrum from acute mortality to rather benign or inconsequential syndromes, all sharing the common feature of a deviation from the normal structure or function of the host. Understanding these deviations among cultured and wild fish populations and balancing their implications against ecological, economic, and political concerns are challenges for both fish health scientists and fisheries managers. The severity of a given disease is dependent on the interaction of numerous variables of the host, the parasite, and the environment. To understand diseases and their impacts on fish populations, we must know which variables are important, how we measure them, and finally how we assess the results of our measurements. We have perhaps been most successful with variables associated with the pathogen. We often can more easily isolate and scrutinize the pathogen than either the host or the environment. The host variables of importance (for which we lack considerable knowledge) include actions of the immune system in general and specifically the influence of genetics and nutrition on host resistance–susceptibility to disease. Lastly, the contribution of the environment, a nebulous term encompassing everything other than the host and pathogen, is only partly appreciated. While we can measure certain physical and chemical parameters of the environment, we have a poor understanding of the biological–ecological variables that influence host–pathogen interactions. Ultimately, diseases of wild fish must be considered in the context of these complex interactions including numerous physical, chemical, biological, and ecological parameters, which may yet be discovered as integral parts of the aquatic habitat.     

基于线粒体Cyt b基因和CR序列的养殖貉(Nyctereutes procyonoides)种群遗传多样性和结构分析

貉(Nyctereutes procyonoides)是一种重要的经济动物。经过50年的人工驯养繁育,国内养殖种群不断扩大,但对其遗传多样性和结构了解很少,难以开展有效的遗传管理。本研究分析了东北、华北地区养殖貉种群(N=160)的线粒体细胞色素b(Cyt b)基因和控制区(CR)序列,并与已经发表的同源序列进行比较。结果定义了5个Cyt b基因和6个CR序列单倍型,其中与俄罗斯产乌苏里亚种共享单倍型分别是3个和4个。种群遗传多样性分析表明,养殖貉种群单倍型多样性处于临界点(Hd=0.50)、核苷酸多样性处于较高水平(Pi>0.5%),但二者均明显低于俄罗斯野生乌苏里貉种群。这种遗传多样性模式可能主要是由奠基者效应(founder effect)导致的。此外,红褐色型貉遗传多样性水平显著低于野生型和白色型貉。系统发育分析表明国内养殖貉种群分为3个世系,主要是乌苏里亚种、与同亚种的俄罗斯野生种群亲缘关系密切。研究还发现有1个单倍型(CH5-DH5)与越南产指名亚种共享同一个单倍型世系。这说明建群引种中可能偶然引入了华南地区分布的指名亚种。综上分析,我国养殖貉种群已经出现遗传多样性下降的迹象,需要监控种群遗传多样性的变化,引入具有新基因型的野生貉种,制定科学的交配模式,避免近交衰退。     

Hematology and serum biochemistry comparison in wild and captive Central American river turtles (Dermatemys mawii) in Tabasco, Mexico

Hematological and serum biochemistry analyses were determined on 51 Central American river turtles (Dermatemys mawii) during the dry and rainy seasons of 2006. Turtles came from two sites: Pantanos de Centla Biosphere Reserve and a turtle breeding farm, both located in Tabasco State, Mexico. Physical examination and body measures of animals were performed. Incidence and prevalence of hemoparasites were explored.Captive organisms were in poor physical condition while wild turtles were apparently healthy. There were differences in several hematological parameters related with the condition and the season. During the dry season captive turtles exhibited higher levels of uric acid and urea, as well as lower levels of glucose. Haemogregarina sp. was detected in 100% of the wild individuals, but not in captive individuals. Its incidence was greater during the rainy season. This is the first health assessment and hematology study of this critically endangered species.     

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.     

Successful treatment of suspected exertional myopathy in a rhea (Rhea americana).

A 7-yr-old, adult, female greater rhea (Rhea americana) from the National Zoological Park presented with a 24-hr history of severe left leg lameness that progressed to an inability to stand. Blood work revealed creatine phosphokinase (CPK) above 50,000 U/L and elevated lactate dehydrogenase. The bird's condition deteriorated over the next week. The bird's CPK increased to over 208,400 U/L. Aggressive intravenous fluids and physical therapy along with oral anxiolytic and muscle-relaxant drugs were instituted. After 2 wk of aggressive therapy, initial signs of improvement were noted. By day 28, the bird was able to walk unassisted with no noticeable lameness. This is one of the few reported cases of successful treatment of suspected ratite exertional myopathy. It is believed that success in this case can be attributed to persistent, aggressive physical therapy, muscle relaxants, and anxiolytics aimed to counteract the hyperexcitable nature of these birds.     

Parental Nutrition and Chick Production in Captive Willow Ptarmigan (Lagopus L. Lagopus)

The breeding performance of captive willow ptarmigan on different diets has been studied. The nutritional factors tested were protein concentration, natural feed supplement and grass meal and flavonoid admixture, and effects on egg numbers, fertility, hatchability, chick weights at hatching and 0–14 days mortality have been recorded.The breeding performance of ptarmigan hen in captivity showed great individual variations. Egg numbers were not statistically different in groups fed the different diets. Hens fed a 15 % crude protein died tended to produce smaller chicks with significantly lower viability than chicks from hens fed a 20 % crude protein diet. Supplement of natural feed tended to increase the number of chicks hatched through a combination of tendency to higher egg numbers and improved fertility. These tendencies were, however, statistically nonsignificant. Inclusion of 34 % grass meal to the diet also tended (non-significantly) to improve fertility and hatchability, while inclusion of flavonoids had no positive effect on reproduction.Eggs from captive hens showed significantly lower fertility, and a tendency to lower hatchability than eggs from wild hens. The former difference was probably caused by the close cage confinements for the captive ptarmigan, while the latter condition probably was due to different start of incubation, most of the eggs from wild hens being started naturally.     

Blood lipid concentrations and lipoprotein patterns in captive and wild American black bears (Ursus americanus)

OBJECTIVE: To compare blood lipid concentrations and lipoprotein patterns for captive and wild American black bears (Ursus americanus). ANIMALS: 7 captive and 9 wild adult (> or = 4 years old) black bears. PROCEDURE: Blood was collected from 2 groups of captive black bears (groups A and B) and 1 group of wild black bears (group C). Blood triglyceride (TG) and cholesterol concentrations were compared among groups. Plasma lipoproteins were isolated by use of a self-generating gradient of iodixanol, and lipoprotein patterns were compared between groups A and B. RESULTS: Captive bears (mean +/- SD, 187.8 +/- 44.4 kg) weighed significantly more than wild bears (mean, 104.8 +/- 41.4 kg), but mean body weight did not differ between groups A and B. Mean blood TG concentrations for groups B (216.8 +/- 16.0 mg/dL) and C (190.7 +/- 34.0 mg/dL) were significantly higher than that of group A (103.9 +/- 25.3 mg/dL). Mean blood cholesterol concentration was also significantly higher for group B (227.8 +/- 8.2 mg/dL) than for groups A (171.7 +/- 35.5 mg/dL) or C (190.8 +/- 26.8 mg/dL). Mean very-low-density lipoprotein TG and low-density lipoprotein cholesterol concentrations were 2- and 3-fold higher, respectively, for group B, compared with concentrations for group A. CONCLUSIONS AND CLINICAL RELEVANCE: Blood lipid concentrations vary significantly among populations of black bears. Plasma lipoprotein patterns of captive bears differed significantly between colonies and may have reflected differences in diet or management practices.     

Differences in helminth infections between captive and wild spur-thighed tortoises Testudo graeca in southern Spain: a potential risk of reintroductions of this species

Although the spur-thighed tortoise, Testudo graeca, is one of the most widely distributed species of tortoises, its natural populations are threatened through its whole range. Particularly at south-eastern Spain, the species is mainly threatened by habitat destruction and over-collection, given that this chelonian has been traditionally considered an appreciate pet. As south-eastern Spanish wildlife recovery centers shelter hundreds of captive animals mainly coming from illegal trade or captive-bred, there is a strong debate about what to do with these animals: maintaining them in captivity all along their lives or reintroducing them to wildlife. It is well known that the reintroduction of captive animals supposes a risk for the wild population due to the uncertainty of their genetic origin and to the possible spread of infectious diseases. However, despite the increasing evidence that infectious agents are a potential health hazard for wildlife, little is known about the risk that introduced parasites could suppose for the wild populations of spur-thighed tortoise. The present study investigates for the first time the presence of helminth eggs and worms in faeces from 107 wild and captive individuals collected from mid-March to mid-June 2010, and relates the findings to different environmental and host variables. Sixteen oxyurid species and the ascarid Angusticaecum holopterum were identified. This last nematode and the oxyurid species Tachygonetria palearticus and T. seurati had not been reported in Spanish wild T. graeca previously. The prevalence of oxyurid eggs and worms were 94% and 70%, respectively; while, ascarid eggs and worms were found in 26% and 5% of tortoises, respectively. Ascarid infections affected mostly captive animals and were associated to caparace deformities and symptoms of upper respiratory tract disease (p<0.05). Oxyurid infections were not associated to negative health traits and prevalence increased with age. In free-living tortoises, the distribution of pharingodonid genera also varied according to habitat; moreover, T. longicollis, T. pusilla, T. conica, T. robusta and Mehdiella stylosa where significantly more frequent in wild compared to captive tortoises (p<0.05). Study results highlight important differences in the nematode fauna of captive and free-living tortoises and questions one more time if the reintroductions of captive animals suppose a risk for the wild population since the former ones can harbor and distribute among free populations pathogens like ascarid nematodes.     

Serum biochemistry of captive and free-ranging gray wolves (Canis lupus).

Normal serum biochemistry values are frequently obtained from studies of captive sedentary (zoo) or free-ranging (wild) animals. It is frequently assumed that values obtained from these two populations are directly referable to each other. We tested this assumption using 20 captive gray wolves (Canis lupus) in Minnesota, USA, and 11 free-ranging gray wolves in Alaska, USA. Free-ranging wolves had significantly (P < 0.05) lower sodium, chloride, and creatinine concentrations and significantly higher potassium and blood urea nitrogen (BUN) concentrations; BUN to creatinine ratios; and alanine aminotransferase, aspartate aminotransferase, and creatine kinase activities relative to captive wolves. Corticosteroid-induced alkaline phosphatase activity (a marker of stress in domestic dogs) was detected in 3 of 11 free-ranging wolves and in 0 of 20 captive wolves (P = 0.037). This study provides clear evidence that serum biochemical differences can exist between captive and free-ranging populations of one species. Accordingly, evaluation of the health status of an animal should incorporate an understanding of the potential confounding effect that nutrition, activity level, and environmental stress could have on the factor(s) being measured.     

Aspects of the Macroscopic Testicular and Epididymal Morphology in the Greater Rhea,Rhea Americana (Linneaus – 1758) Birds

The purpose of this research was to study the macroscopic testicular and epididymal morphology of the greater rhea. The testicles of 54 greater rhea bred in captivity were utilized. The samples were collected November 2005 (n = 14), December 2006 (n = 20) and May 2007 (n = 20). During commercial slaughter, the testicles and epididymides were collected and their following morphometric parameters were immediately measured: length, width, thickness, circumference, volume, weight of the parenchyma and the tunica albuginea, also aspects such as shape, cavity implantation, relationship with other organs and vascularization. The testicles presented cylindrical shape, with a thin, dense and transparent tunica albuginea, and the vascularization was accomplished by the testicular artery that ramifies from the cranial rectal artery. In the samples from December 2006 and May 2007, the media from the macroscopic measures of the right testicles were volume 58.7 and 14.7 ml, length 9.87 and 3.5 cm, width 2.4 and 0.6 cm, thickness 2.4 and 0.5 cm, circumference 8.0 and 2.3 cm, parenchyma weight 27.6 and 6.1 g and tunica albuginea weight 1.0 and 0.3 g, P < 0.05, respectively. The epididymides, the media from macroscopic measures December 2006 and May 2007 were volume 7.7 and 3.0 ml, length 5.8 and 1.3 cm, width 0.7 and 0.3 cm, thickness 0.6 and 0.3 cm, circumference 2.5 and 1.2 cm, tissue weight 6.4 and 2.8 g and capsule weight 0.4 and 0.1 g, P < 0.05, respectively. Some measures from the right testicle and epididymis were superior to measures taken from the left ones (P < 0.05), but these were not characterizing asymmetry. The morphometric parameters observed during November 2005 remained on an intermediate situation (P < 0.05); however, they were quantitatively closer to the means of December 2006, which may characterize it as a potential transition period between repose and sexual activity. Morphologically, the testicles and epididymides of greater rhea have common points with other researched birds; however, differences were observed. The testicles and epididymides of the Rhea americana are influenced by the environment, presenting reproductive activity season (November–December) during late spring, early summer and sexual repose season (May) during autumn–winter. The morphometric testicular and epididymal measurements were introduced. The morphometric parameters of testicles and epididymides exhibited differences between winter and spring–summer that could be established like sexual activity season.