Pathological changes of tracheal mucosa in chickens infected with infectious laryngotracheitis virus

Six-week-old chickens were inoculated via the posterior thoracic air sac with infectious laryngotracheitis virus. Chickens were sacrificed on various days through day 16 postinoculation (PI), and the trachea was examined by scanning electron microscopy (SEM) and light microscopy (LM). The pathological changes observed on day 1 PI were hypertrophy and hyperplasia of goblet cells. From day 3 PI, the epithelial cells protruded collectively and fused to form syncytia, which contained many intranuclear inclusion bodies. Subsequently, epithelial syncytia desquamated, one after another, and connective tissues were exposed in places. Serofibrinous exudate and detritus were abundant on the surface of the exposed connective tissues and seemed to form a pseudomembrane. On day 5 PI, the remaining epithelial cells began to repair the devastated mucosa just under the pseudomembrane. On day 6 PI, microvillus-rich regenerating epithelial cells were arranged like paving stones. On day 8 PI, the epithelial cells proliferated extensively and formed folds with cyst-like structures. By day 16 PI, the tracheal epithelium was covered with cilia and regained its normal histologic appearance.     

Geographical variation of the skull morphology of the common tree shrew (Tupaia glis).

Geographical variation was examined morphologically in the common tree shrew (Tupaia glis) in some Indochinese and Malayan regions. Osteometrical examination and principal component analysis elucidated the morphological differences among various populations. The populations from southern and western Thailand were distinguished morphologically from the other populations. Variation in males from south Thailand and Kuala Lumpur suggests that the Isthmus of Kra may have an influence on the variation of skull morphology. However, the Isthmus of Kra was not completely considered as a factor of geographical separation in this species, because we could not confirm the separation in skull size and shape between the localities at least in females. While, the Kanchanaburi population in western Thailand was significantly smaller than the other population in skull size, and constituted the morphologically separable group in our study.     

Structural Changes of Goat Parotid Salivary Gland: Pre‐ and Post‐Weaning Periods

Previously, the structure of the adult goat parotid salivary glands (PGs) was studied. However, little information was elucidated of the juvenile ones. This study aimed to clarify the correlations between the structure of goats' PGs and the nature of food intake among milk‐suckling kids (MSKs) and diet‐fed goats (DFGs). The secretory endpieces of the goats' PGs are of the pure serous type. The serous cells in MSKs showed apical accumulation of numerous secretory granules (SGs) of smaller size and of more intense positive periodic acid‐Schiff reaction. Ultrastructurally, most of the SGs in the DFGs contained peripherally located inclusions that showed dense reaction products for acid phosphatase. In MSKs, the PGs showed less‐developed basal infoldings, sparseness of the inter‐cellular inter‐digitations, fewer inter‐cellular canaliculi and microvilli and also less‐developed myoepithelial cells with fewer and shorter cytoplasmic processes. In conclusion, the less‐developed membrane specializations and myoepithelial cells, as well as the accumulated SGs in the PGs of MSKs, suggest that it secretes less saliva with a little secretory activity than that of DFGs, which may be correlated with the reduced masticatory activity.     

Fate of cystic ovarian follicles and the subsequent fertility of early postpartum dairy cows

The fate of cystic ovarian follicles that developed spontaneously during the early postpartum period of 50 lactating dairy cows was traced by ultrasonography to characterise the follicular dynamics in relation to the fertility of the cows. The absence of postpartum ovulations caused by repeated waves of anovulatory large follicles was also characterised and evaluated. Fifteen of the 50 cows developed cystic follicles, and these follicles became follicular cysts in five of the 15 cows. Most of the cystic follicles emerged before the first postpartum ovulation of the cows. The transition from cystic follicles to follicular cysts delayed the cows' first ovulation, oestrus and insemination, but had less influence on their fertility after they had recovered spontaneously. In addition to the 15 cows that developed cystic follicles or follicular cysts, six of the cows had five to 13 waves of follicles before their first ovulation. These repeated waves of follicles caused a more severe delay in the early postpartum reproductive events but did not affect the cows' fertility.     

Primary erythrocytosis in a Japanese black calf: a case report

An 8-month-old Japanese Black heifer with severe erythropoietic symptoms was subjected to clinical, histological and cytological examinations. During the 1 month clinical observation period, severe increases in RBC count, packed cell volume and haemoglobin concentration were observed. The plasma erythropoietin (Epo) concentration of the heifer (20.7 mIU/ml) was similar to that observed in normal control heifers. Blood gas examinations of the arterial and venous blood revealed low levels of partial pressure O(2) (PaO(2)), partial pressure CO(2) (PaCO(2)) and O(2) saturation (SaO(2)), while the blood pH was within the normal range. Gross lesions could not be detected. However, microscopic observation revealed severe proliferation of erythroblasts in the bone marrow and in the spleen without evidence of neoplastic changes. Based on these clinical and pathological examinations, we diagnosed the heifer as being the first case of primary erythrocytosis in Japanese Black cattle.     

Energy exchanges of broilers, selected for fatness and leanness, on diets with and without a repartitioning agent.

1. Two experiments were undertaken for 3 or 5 d in respiration chambers, on two experimental lines of broiler chickens (aged 25-38 d) selected for leanness and fatness. Diets were without or with 0.4 mg cimaterol per kg. 2. The lean line with sexes combined (experiment 1), or with females only, had a significantly greater heat production than the fat line. Net availability of metabolisable energy for gain (kg) was 0.54 for the lean birds and and 0.84 for the fat birds. 3. Cimaterol did not have an effect on any of the variables examined.