Veterinary Research Forum

Abstract The ostrich (Struthio camelus) is an important wild species highlighted in national and international livestock industry. This research was conducted to analyze the development of the ostrich respiratory system during fetal and embryonic stages. A total of 50 fertile ostrich eggs were collected from commercial farms and then incubated at 36.00 - 37.00 ˚C and 25.00 ± 2.00% humidity for 40 days. Sections were taken on days 13, 22, 26, 30, 36, and 42 of incubation from the lung and the cranial, middle, and caudal parts of the neck after decapitation of ostrich embryos and blood drainage. After fixation, processing, blocking, and sectioning, all samples were stained by Hematoxylin and Eosin, Alcian Blue (AB), Van Gieson, and Periodic acid-Schiff (PAS) techniques. It was concluded that the trachea in the 13-day-old embryo and goblet cells (PAS-positive and AB-positive) had incomplete rings of hyaline cartilage and differentiation of mesenchymal to the loose connective tissue. The bronchial stage of the lung was observed in the 22-day-old embryo, pseudoglandular stage in the 26-day-old embryo, and parabrachial and air capillary stage in the 30-day-old embryo. The information obtained from this study will be useful for diagnosing pathologies affecting this vital system and results in improving industrial breeding management.

Abstract In this research, anatomical descriptions of the structure of the temporal bone and auditory ossicles have been performed based on dissection of ten guinea pigs. The results showed that, in guinea pig temporal bone was similar to other animals and had three parts; squamous, tympanic and petrous .The tympanic part was much better developed and consisted of oval shaped tympanic bulla with many recesses in tympanic cavity. The auditory ossicles of guinea pig concluded of three small bones; malleus, incus and stapes but the head of the malleus and the body of incus were fused and forming a malleoincudal complex. The average of morphometric parameters showed that the malleus was 3.53 ± 0.22 mm in total length. In addition to head and handle, the malleus had two distinct process; lateral and muscular. The incus had a total length 1.23 ± 0.02mm. It had long and short crus although the long crus was developed better than short crus. The lenticular bone was a round bone that articulated with the long crus of incus. The stapes had a total length 1.38 ± 0.04mm. The anterior crus(0.86 ± 0.08mm) was larger than posterior crus (0.76 ± 0.08mm). It is concluded that, in the guinea pig, the malleus and the incus are fused, forming a junction called incus-malleus, while in the other animals these are separate bones. The stapes is larger and has a triangular shape and the anterior and posterior crus are thicker than other rodents. Therefore, for otological studies, the guinea pig is a good lab animal.