During 3hr of incubation, the production of progesterone in the follicle wall from the largest preovulatory follicle (F1) of the Japanese quail was stimulated by ovine LH or dibutyryl cyclic AMP. The follicle walls from the second largest and the third largest follicles (F2 and F3) did not produce appreciable amounts of progesterone, while the granulosa cells isolated from these follicles produced significant amounts of progesterone. By incubating progesterone with the cell-free homogenates of the theca layer in the presence of NADPH, it was clarified that the metabolic rates of progesterone in the theca layer of F2 and F3 were higher than that of F1. These results suggested that in the quail follicles, progesterone is produced in the granulosa layer but the theca layers of the small follicles metabolize progesterone, so that only F1 secretes progesterone.

View full abstract

The experiment was performed in order to investigate the phase response of oviposition to a shorter light pulse and the precision of distinction of the length of the two dark periods under asymmetric skeleton photoperiods. 450 White Leghorn hens of 32 weeks of age were divided into two groups and treated the following asymmetric skeleton photoperiods; 9L:15D (light-on at 08:00), 9L:1D:1L:13D, 9L:4D:1L:10D, 9L:7D:1L:7D, 9L:10D:1L:4D, 9L:13D:1L:1D and 9L:15D. The order of the treatments in groups 1 and 2 was reversed. Each photoperiod was treated for three weeks and time of oviposition of each bird was recorded.
The phase response for the timing of oviposition to a 1 hour light pulse was 30 to 40 minutes under the photoperiods with two unequal dark periods, but the photoperiod of 9L:7D:1L:7D which is divided into equal dark periods the phase response was almost zero irrespective of the previous treatment. It is suggested that bird can distinguish the difference of the length of the two dark periods under asymmetric skeleton photoperiods very precisely.

View full abstract

Phosphorus content and availability of phosphorus were determined in the ash which was produced by burning of broiler waste (Waste burning ash).
Phosphorus contents in waste burning ash varied from 11.4 to 12.8%. Availability of phosphorus in waste burning ash was 88 on an average, which was determined by biological assay method of Yoshida and Hoshii (1977).

View full abstract

Two experiments were conducted to investigate the possibility of sea weed as a pellet binder. Experimental diets were prepared by adding sea weed to a basal diet at the level of 2 and 5%. These diets were nonsteam pelleted by using a labolatory pellet mill (2 HP CPM Model CL-type 2) with a 3/16 inch die.
Three varieties of sea weeds tested certainly improved the pellet quality, namely, productive efficiency, bulk specific weight, pellet hardness and pellet durability index. To obtain the same durability as bentonite (2.5%) or lignin sulfonic acid (2.0%) addition, 3.9% addition of Laminaria diabolica, 9.4% addition of Laminaria longissima or 6.2% addition of Laminaria japonica was needed.

View full abstract

Although it is desirable that a chicken house floor contaminated heavily with bacteria is washed by jet stream with brushing, the brushing by man power is not easy in practice. Effects of painting the floor and of brushing by mechanical power were examined.
1) Bacterial counts of a broiler house floor with and without painting were 10^6.5 per cm². After washing with brushing by man power, bacterial counts on the both floors were reduced to 10^4.8/cm². Painting the floor had little effect to reduce bacterial count.
2) The floor without painting was washed with brushing by mechanical power. A loader attached with rotary brush was used. When revolution of rotary brush was 120 rpm and the loader moved 3.5 km per hour, bacterial counts on the floor were almost the same to those observed after washing by man power. After washing, 10^5.1/cm² of bacteria were detected from the floor washed by mechanical power and 10^4.9/cm² of bacteria by man power.

View full abstract