The topography of the thoraco-abdominal viscera in the ostrich (Struthio camelus)

The topography of the thoraco-abdominal viscera in the ostrich was studied in 20 birds varying in age from 2 weeks to 12 months. The lungs occupied the dorsal third of the thorax, and the heart lay in the cranioventral thorax perpendicular to the long axis of the body. There was no pleural cavity. The liver was situated in the caudoventral part of the thorax, and the proventriculus occupied the left cranial part of the abdomen between the 7th vertebral rib and the acetabulum. The gizzard lay in the cranioventral part of the abdomen, resting on the sternum and abdominal floor. The duodenum formed a loop from right to left, with the pancreas lying between the 2 limbs of the loop. The coiled jejunum and ileum occupied the ventral part of the abdomen between the gizzard and pelvis. The two caeca lay on either side of the terminal ileum with their apices in the pelvis. The rectum was the longest part of the intestine and could be divided into a thick proximal segment situated in the right dorsal part of the abdomen, and a thin distal part that occupied the left caudodorsal part of the abdomen. The trilobed kidneys lay along the ventral surface of the synsacrum, with the adrenal glands at their cranioventral poles. The testes lay ventrally to the cranial divisions of the kidneys, whereas the left ovary was situated ventrally to the cranial division of the left kidney. The spleen lay wedged in between the right kidney, caudal vena cava and proventriculus. The thyroid glands were situated at the cranial borders of the subclavian arteries, and the thymus lay at the base of the neck.     

Macro-microscopic study on the toepad of ostrich (Struthio camelus)

The ostrich foot has four toepads, two on the 3rd digit, one on the 4th digit and one at metatarso-phalangeal joint. Previous studies have not detailed the histo-morphological structure of these toepads. In this study, we have described the macroscopic and microscopic structures of the toepad of ostrich (Struthio camelus). Numerous papillae with different direction, length and thickness have been observed grossly on the ventral surface of each toepad. Histological examinations have revealed that the epidermis of the ostrich toepad, similar to other digitigrades, consists of an outer stratum corneum and an inner stratum germinativum (which is subdivided into basal, intermediate and transitional layers). The stratum corneum has several layers of flattened horny cells. The nuclei of basal cells have several mitotic figures. The cytoplasm of the stratum germinativum cells has multiple lipid droplets and multigranular bodies (in transitional cells only). Scanning electron microscopic examination revealed presence of collagen fibers in mid and deep dermis of each toepad. These fibers run parallel and connect to each other by very thin fibrils which are branched, crossed with each other in an oblique direction. Such arrangement of these collagen fibers, thin fibrils and presence of digital cushion are likely to be responsible for the protection of the underlying soft tissues and absorption of concussion.     

Aspergillus fumigatus infection in an ostrich (Struthio camelus)

An 11-month-old female ostrich (Struthio camelus) had become gradually emaciated over a 2-week period and subsequently died. Necropsy revealed white to green mold growth on the walls of caseous thickened air sac membranes and multiple white necrotic foci in the lungs and liver. Histologically, the multiple exudative, necrotic and granulomatous lesions were compatible with mycotic infection in the air sacs and lungs, and hyphae positively reacted with a monoclonal antibody (Mab-WF-AF-1) to Aspergillus fumigatus wall fractions. Multifocal hepatic necrosis was also found, and several spores were observed in the blood vessels. Fungal culture of these lesions yielded pure growth of A. fumigatus. This is an established case of fatal A. fumigatus infection in an ostrich reared in Japan.     

Growth in the ostrich (Struthio camelus var. domesticus)

The use of the ostrich as a livestock animal necessitates an understanding of its ability to utilize specific nutrient requirements if efficient growth is to be realized. Male ostriches may have to be raised separately as they grow faster; they require higher protein diets and are more efficient feed converters for longer periods than female ostriches. Male ostriches exhibit slightly faster maturation rates than female ostriches. The corresponding age at which maximum growth is attained is 181 days for male ostriches and 199 days for female ostriches. The growth curve of ostriches is sigmoid and asymptotic. Body mass reached in 1 year is approximately 104 kg. The metabolic age of ostriches at hatching is approximately 13.7 days. Feed conversion has an impact on growth. The ostrich chick (aged <2 months) has a high feed conversion to body mass ratio of 2:1, which requires very accurate and careful management of chick nutrition.     

Conjunctival mucinous adenocarcinoma in an ostrich (Struthio camelus)

A 2‐year‐old male ostrich (Struthio camelus) presented with a rapidly growing soft tissue mass protruding from the ventromedial aspect of the right eye (OD). The initial physical examination revealed a soft tissue mass attached to the medial inferior conjunctiva. The mass was excised with cryosurgery, and the conjunctival tissue margins were treated with cryoablation. Histopathological examination diagnosed granulomatous inflammation associated with scattered acid‐fast bacteria. The ostrich recovered uneventfully and appeared healthy until recurrence of a grossly similar mass 2 months later. Gross examination revealed a botryoid mass attached to the inferior palpebral conjunctiva and extending onto the palpebral aspect of the nictitating membrane. Euthanasia was selected, and the histological diagnosis of the second mass was a mixed mucinous adenocarcinoma; however, no acid‐fast bacteria were seen. Granulomatous conjunctival lesions have been previously described in the ostrich, while, to the authors' knowledge, neoplastic conjunctival lesions have not. Neoplasia should be considered as a differential diagnosis for a rapidly recurring, granulomatous conjunctival mass in this species.     

Yolk sac utilization in ostrich (Struthio camelus) chicks

The mass of residual yolk sac expressed as a percentage of initial mass of the egg from which the chick hatched decreased sharply in the first 2 days post-hatching. A gradual reduction occurred between 3 and 10 days after which a sharp decline was noted between 11 and 13 days post-hatching. The highest number of chicks with unabsorbed yolk sac was noted on day 5 post-hatching followed by days 6 and 7. Chick mortality followed the same pattern. The dynamics, causes and clinical consequences of yolk sac utilization are discussed.     

Characterisation of tetra-nucleotide microsatellite loci in the ostrich (Struthio camelus)

1. Eleven polymorphic tetra-nucleotide microsatellite loci were identified in the ostrich (Struthio camelus) using a selective enrichment protocol.

2. The average number of alleles observed was 6·6 with an average heterozygosity of 0·4.

3. The population was found to be in Hardy-Weinberg equilibrium and two of the loci had a greater than 95% probability of having null alleles.

4. These microsatellite loci will add to the existing pool of markers available for the ostrich and help to facilitate analysis of population structure and pedigree determination.     

Isolation of Lactobacillaceae bacteria from feces of ostrich (Struthio camelus)

The ostrich (Struthio camelus) is an herbivorous bird with a long and developed hindgut. In the hindgut, there is a dense and highly diverse population of anaerobic bacteria, and active fermentation produces high concentrations of short-chain fatty acids. Bacteria in the hindgut of the ostrich are considered vital for both their nutritional contribution and health benefits, such as benefits to the immune and defense system of the host. We attempted to isolate Lactobacillaceae, which might be involved in improving immune function and in inhibiting pathogens. The number of colonies from ostrich feces observed on LBS agar medium was 3.64×10³ per gram of feces. Three strains of Lactobacillaceae were isolated from the feces. Nearly the entire length of the 16S ribosomal RNA gene of these isolates was sequenced, and a homology search showed high identity with L. brevis (identity=99.93%), L. coryniformis (98.39%), and L. paracasei (100.0%). These isolates may be deemed potential probiotics for the ostrich.     

Nutrition of ostrich (Struthio camelus var. domesticus) breeder birds

This review discusses current data on nutrition in ostrich breeding birds. Nutritional demands increase during breeding particularly the calcium and phosphorus requirements for egg production. The correct balance of amino acids, vitamins and carbohydrates is important for the maintenance of high fertility after the attainment of sexual maturity at 24 months of age for female birds and 36 months of age for male birds. Most problems relating to health and performance, including fertility, hatching, chick survival, growth rates and deformities in the early weeks, are usually traced to inadequate breeder rations.     

The fine structure of the Harderian gland in the ostrich (Struthio camelus)

The Harderian gland of the ostrich (Struthio camelus) is a tubuloalveolar gland containing holocrine secreting epithelial cells. The gland epithelium is composed of two different cell types, which can be classified as type I and type II. These cells contain dense secretory vesicles in their cytoplasm and they are connected laterally with desmosomes. At the basal site of these cells, myoepithelial cells are present. Plasma cells are observed in the subepithelial region of the gland. In the interlobular trabeculae, forming the gland stroma, fibroblasts, blood vessels and nerve fibres are included. Another important finding in the ostrich Harderian gland is the presence of homogeneous material.     

Mycobacterium avium infection in an ostrich (Struthio camelus).

Acid-fast organisms were identified by histopathology of granulomatous lesions in an ostrich (Struthio camelus). The organisms were grown in Herrold's egg media with and without mycobactin and identified as Mycobacterium avium. An agar gel immunodiffusion (AGID) test for Mycobacterium avium paratuberculosis was performed for detection of antibody for M. avium in this infected ostrich and seven other ostriches that were in contact. The results of the AGID were consistent with the pathologic diagnosis of mycobacteriosis and the isolation of M. avium in the affected ostrich.     

The major blood vessels of the wing of the ostrich (Struthio camelus)

The major blood vessels of the ostrich wing were studied by dissection of the wings of 8 ostriches. The axillary artery entered the caudo-ventral aspect of the wing and divided into the brachial and deep brachial arteries. The deep brachial artery gave rise to the radial and ulnar collateral arteries which supplied the caudodorsal aspect of the brachium. The brachial artery divided in the cubital fossa into the smaller ulnar and large radial arteries. The ulnar artery supplied the cranio-ventral aspect of the antebrachium and manus, and the radial artery the caudo-ventral and dorsal aspects of the antebrachium and manus, including the feathers. With few exceptions the veins corresponded with the arteries that supplied the region they drained. The basilic vein passed along the cranial margin of the wing, unaccompanied by arteries or nerves, to drain the major part of the wing. The brachial artery and the basilic veins were the vessels most accessible for arterio- and venipuncture, respectively.     

Development of the refractive state in eyes of ostrich chicks (Struthio camelus)

OBJECTIVE: To follow the development of the refractive error in the eyes of ostrich chicks from age 0 to day 37 after hatching. ANIMALS: 35 ostrich chicks. PROCEDURES: Spot retinoscopy was conducted to assess refractive error in ostrich chicks. Seventy eyes of 35 ostrich chicks were examined. Of these, 18 chicks were followed over time. At least 4 serial measurements (at 2- to 7- day intervals) were conducted in each of these chicks from day 1 to 37 after hatching. Seventeen additional chicks were examined on days 0, 3, 12, and 19 after hatching. RESULTS: Ostrich chicks were myopic at hatching, with a mean +/- SD refractive error of -4.47 +/- 0.15 diopters (D). The refractive error rapidly decreased during the first week of life, and by day 7 after hatching, chicks were slightly hyperopic, with a mean refractive error of 0.42 +/- 0.12 D. After day 7, there were no significant differences in the mean refractive error. CONCLUSIONS: The development of optics in the ostrich eye appears to be unique among animals and is characterized by myopia at hatching, rapid onset of emmetropia, and minimal variation in refractive error among chicks.