Mate choice, maternal investment and implications for ostrich welfare in a farming environment

Endoparasitism of Greek ostriches: First report of Entamoeba struthionis and Balantioides coli

Ostrich farming is a worldwide practice and an internationally developing industry. Among challenges in livestock production are the parasitic infections. The present study aimed to the investigation of the gastrointestinal parasites biota and prevalence in ostriches raised in different areas of Greece. A total of 141 clinically healthy ostriches originating from four different localities of Greece were coprologically examined for parasites of the gastrointestinal tract. Coprological examination revealed a considerably high rate of infection (65.9%) with protozoa; however, no helminths (trematodes, cestodes and nematodes) were detected. In detail, cysts of Entamoeba struthionis have been found in 57.4% of the examined birds. Moreover, 39.0% of sampled ostriches harboured cysts of Balantioides coli (syn. Balantidium coli), while oocysts of Cryptosporidium sp. were detected at a low percentage (2.1%). Partial sequences of the small subunit rRNA (16S rRNA) gene and the ITS region were amplified from pooled Entamoeba and Balantioides positive samples, respectively, confirming for the first time the presence of Entamoeba struthionis and Balantioides coli in ostriches in Greece. Some of these parasitoses require attention as they may affect productivity performance of the animals in commercial ostrich farming and possibly pose disease risk for livestock and humans.

Sperm macrocephaly syndrome in the ostrich Struthio camelus: morphological characteristics and implications for motility

Sperm macrocephaly syndrome (SMS) is characterised by a high percentage of spermatozoa with enlarged heads and multiple tails, and is related to infertility. Although this multiple sperm defect has been described in other mammalian species, little is known about this anomaly in birds. Morphological examination of semen from nine South African black ostriches (Struthio camelus var. domesticus) involved in an AI trial revealed the variable presence of spermatozoa with large heads and multiple tails. Ultrastructural features of the defect were similar to those reported in mammals except that the multiple tails were collectively bound within the plasmalemma. The tails were of similar length and structure to those of normal spermatozoa, and the heads were 1.6-fold longer, emphasising the uniformity of the anomaly across vertebrate species. Flow cytometry identified these cells as diploid and computer-aided sperm analysis revealed that they swim slower but straighter than normal spermatozoa, probably due to the increased drag of the large head and constrained movement of the merged multiple tails. The high incidence of this defect in one male ostrich indicates that, although rare, SMS can occur in birds and may potentially have an adverse effect on breeding programs, particularly for endangered species.

The Effect of Extensive Human Presence at an Early Age on Stress Responses and Reactivity of Juvenile Ostriches towards Humans

The effect of extensive human presence and regular gentle handling performed at an early age (0⁻3 months old) on stress responses and reactivity of juvenile ostriches towards humans was investigated. A total of 416 ostrich chicks over two years were exposed to one of three treatments for three months after hatching; namely, Human Presence 1 (HP1, N = 144): extensive/prolonged human presence with physical contact (touch, stroking), gentle human voice, and visual stimuli; Human Presence 2 (HP2, N = 136): extensive/prolonged human presence without physical contact, but with gentle human voice and visual stimuli; and the Standard treatment (S, N = 136): human presence limited to routine feed and water supply as a control. At 7.5 months of age, the plasma heterophil/lymphocyte (H/L) ratio was measured before and 72 h after feather harvesting and feather clipping to determine acute stress responses, while chronic stress was measured by quantification of corticosterone (CORT) concentrations in the floss feathers of the birds. Birds' behavioural response towards a familiar or an unfamiliar handler was evaluated at 12 months using docility and fear tests, and through behavioural observations conducted on random days between the ages of 8⁻13 months. Willingness to approach, and to allow touch interactions, aggressiveness, and exhibition of sexual display towards the handler, was recorded. No difference in the H/L ratios before and after feather harvesting and clipping was observed in HP1 birds, whereas H/L ratios showed a significant increase 72 h post feather harvesting and clipping in HP2 and S birds (p < 0.05). Birds from the S treatment exhibited a significantly (p < 0.05) higher feather CORT concentration compared with HP1 birds, while HP2 birds had intermediate responses. Birds' reactivity towards humans and temperament as evaluated using behavioural observations, docility, and fear tests was not affected by treatment (p > 0.05). However, HP1 and HP2 birds were more inclined (p < 0.05) to approach a familiar rather than an unfamiliar handler during the behavioural observations, indicating an ability to distinguish between a familiar and an unfamiliar handler. Overall, the results indicate that early gentle human interactions with ostrich chicks can be beneficial in reducing physiological stress sensitivity later in life and facilitate the ability of ostriches to distinguish between familiar and unfamiliar handlers.