Yoshio Nakahiro

Scanning and transmission electron microscopic observations of bacteria adhering to ileal epithelial cells in growing broiler and white leghorn chickens

1. Bacteria adhering to the ileal epithelial cells in broiler and White Leghorn (WL) chickens aged 1 to 60 d were observed with scanning (SEM) and transmission (TEM) electron microscopes. 2. In SEM observations, bacteria were not found on day 1 after hatching in either breed. In 10-d-old broilers many bacteria were observed around the apical area of villi. The number decreased with age and disappeared by 50 d. In WL chicks, the bacteria were first observed at 20 d. Numbers were much fewer than in broilers and none were seen after 30 d. 3. TEM investigations showed that bacteria had a cytoplasmic membrane, cell wall and nucleus but no nuclear membrane and organella, were compartmentalised and resembled Streptobacillus moniliformis. At the attachment zone to the epithelium, many mitochondria were observed in the epithelial cells; the bacterial membrane did not fuse to the epithelial cell membrane except at the apex of the attachment end where the bacterial membrane seemed to undergo lysis, suggesting a possibility that some bacterial components were transferred to the epithelial cells. 4. It is possible that the bacterial aid in the functioning of ileal epithelial cells. Possible functions are discussed in relation to the morphological features.

Some factors affecting urinary and faecal nitrogen loss by chickens fed on a protein-free diet.

1. In adult colostomised cockerels, the rates of urinary and faecal nitrogen loss were measured when feeding low- and high-energy, protein-free diets after a preliminary period during which diets of differing energy and protein contents had been fed. 2. Urinary nitrogen excretion increased with increasing protein and decreasing energy in the preliminary diet. 3. Urinary nitrogen excretion was high during the fist 3 d of feeding a high-energy, protein-free diet, decreased rapidly during the next 3 d and thereafter become relatively constant. However, in the case of a low-energy, protein-free diet, urinary nitrogen excretion gradually declined throughout the trial period of 15 d, resulting in increased urinary nitrogen excretion. 4. After a 3-d period of adjustment faecal nitrogen loss from birds fed on a protein-free diet was relatively constant under the conditions examined.

Ultrastructural alterations of the thyroid follicular cells in domestic fowls following neonatal olfactory bulbectomy.

1. In order to investigate if ultrastructural alterations of thyroid follicular cells are induced by removal of the olfactory bulb at hatching, chicks were olfactory bulbectomised within 24 h after hatching and the thyroid follicular cells were examined at 5 months of age by electron microscopy. 2. Olfactory bulbectomised chickens showed a well-developed Golgi area, a highly-developed rough endoplasmic reticulum, many mitochondria and a paucity of secretory granules and lysosomes in thyroid follicular cells. 3. These hypertrophic ultrastructural changes in follicular cells of operated birds indicated that the thyroids glands were stimulated by neonatal olfactory bulbectomy. 4. This finding may suggest an establishment of the olfactory bulbothyroid glandular system during the early days of life in the chicken.

Water Absorption from the Ceca of Chickens

鶏について,水分吸収に及ぼす盲腸の影響を調べるために,育腸を切除,結紮あるいは切断して実験した結果,次のことが明らかになった.1. 盲腸の切除,結紮または切断によって,水分摂取量および水分排泄量は増大する傾向にあるが,水分出納にはこれらの間に差異は認められなかった.2. 盲腸を結紮ならびに切断した鶏に人工肛門を設着し,摂取水分の糞尿別排泄量について調べた結果,盲腸機能の喪失により増大した排泄水分は主として糞中に排泄された.したがって,盲腸を結紮あるいは切断した鶏においては,盲腸による水分吸収が失なわれるために糞中への水分排泄量が多くなり,これを補うために水分摂取量の増大をきたすものと考えられる.すなわち盲腸のもつ水分吸収機能は,盲腸以外の腸管により完全には代償され難いものであることが示唆された.