The effect of graded levels of dietary urea were studied on chicks given a basal diet containing adequate amounts of all the essential but none of the non-essential amino acids. With the increase of dietary urea, body weight gain curvilinearly increased and the chicks fed 2.06% or more dietary urea grew significantly better than the chicks fed the basal diet alone. Feed intake and feed efficiency followed the similar pattern as the growth rate. With the increase of dietary urea level, nitrogen retention ((mg N intake-mg N excreted)⁄g feed intake) increased, but nitrogen utilization ((mg N intake-mg N excreted)⁄mg N intake) was reduced. Blood ammonia concentrations were similar irrespective of dietary urea levels. Plasma uric acid concentrations increased, but not significantly, with increasing amounts of dietary urea. Total N and ammonia N in the gut contents were not markedly affected by the dietary urea supplements, but total N and, to some extent, ammonia N were higher in the lower gut contents. With the increment of dietary urea, urea N in the upper gut increased linearly, while in the lower gut did curvilinearly. It was considered that dietary supplements of urea are beneficial for chicks under conditions where dietary non-essential amio acids are limiting.

View full abstract

Hemisected pituitaries of cods were incubated in vitro at 41°C for 3hr with and without testosterone. progesterone, or estradiol-17β (1 and 10ng/ml), and media were assayed for the gonadotropic activity by using a bioassay method based on ³²P-uptake by chick testes. The media in which the pituitary halves were incubated with testosterone (10ng/ml) showed a greater gonadotropic activity than those in which the other pituitary halves were incubated without testosterone. Incubations with progesterone or estradiol-17β did not result in a change in the gonadotropic activity of the media. When pituitaries were divided into cephalic and caudal lobes, and each lobe was hemisected and incubated in the same way, the incubation of the cephalic lobes with testosterone (5 and 10ng/ml) resulted in the increase in the gonadotropic activity of the media, while the incubation of the caudal lobes did not result in the increase. Synthetic GnRH (250 and 500ng/ml) caused the increase in the gonadotropic activity of the media in both incubations of the cephalic lobes and of the caudal lobes. The results suggest that testosterone acts on the pituitary and leads to the release of gonadotropins, and that the responsiveness of the pituitary to testosterone differs between the cephalic and caudal lobes.

View full abstract

Re-examination on the potassium requirement, i.e., 0.20% of dietary level which is recommended as Japanese Feeding Standard, was performed by feeding the purified diet with casein mixture as protein source to White Leghorn and meat-type chicks for three weeks. In both White Leghorn and meat-type chicks, more than 0.15% of dietary potassium level was completely preventive against chicks' mortality resulted from potassium deficiency.
Potassium requirement until 1, 2, and 3 weeks of age was determined to be 0.37, 0.34, and 0.34%, respectively, for White Leghorn, and to be 0.30, 0.28, and 0.24, for meattype chicks, tending to be lowered with chick's growth. Consequently, all of the requirement until 1, 2, and 3 weeks of age were higher than 0.20%, the recommended level as Japanese Feeding Standard. Therefore, it was clarified in this experiment that 0.20% of dietary potary potassium level was insufficient for maximal growth of starting chicks. It was also revealed that there was a breed difference between White Leghorn and meat-type chicks in the potassium requirement.

View full abstract

Cerebral esterase of the quail was examined by the use of starch gel electrophoresis. Two groups of the domestic quail and one group of the quail wild-trapped were used in the present study. In addition to the cerebral esterase isozyme system Es II previously reported by Emura et al. (1974), an individual variation was found. Some of the wild quails lacked the esterase band in the region III, while other quails had an intensely stained esterase band in this region. Survey on family data suggests that the variation is under control by two autosomal alleles, Es III^A and Es III⁰. Quails homozygous for the allele Es III⁰ lack the esterase band in the region Es III.

View full abstract

For a physiological characterization of an apparent breed difference observed in survival time without feed and/or water, feed intake, water intake, body temperature, skin temperature and the plasma levels of glucose and protein on ad libitum feeding under different environmental temperatures were compared in White Leghorn males of two strains, dwarf (dwarf-WL) and non-dwarf (normal-WL), Fayoumi and Silky males at 32 weeks of age.
Birds were kept at the room temperature of 16, 23 and 30°C.
Normal-WL that survived the shortest periods of time without feed and/or water than other breeds in our previous work3) consumed the most feed and water in four breeds utilized in this investigation at 30°C. On the other hand, dwarf-WL that survived the longest periods of time without feed and/or water consumed the least feed and water in four breeds at 30°C.
It was observed in normal-WL, dwarf-WL and Fayoumi that feed consumption was decreased with the rise of environmental temperature, and water consumtion was increased. However, in Silky breed, feed consumption was increased with the rise of environmental temperature.
Dwarf-WL consumed the least amount of water per unit of body weight among these breeds in each environmental temperature.
Plasma total protein, plasma glucose levels and skin temperature changed with the rise of environmental temperature. Changing pattern in Silky breed were differed from other breeds.

View full abstract

The effect of washing and oiling on polyacrylamide disc gel electrophoretograms of albumen of the chicken eggs stored for 9 weeks was studied. The electrophoretograms of chicken albumen revealed the presence of 15 electrophoretic protein bands which are desingnated prealbumin (No. 1), ovoalbumins (Nos 2, 3, 4), prealbumins (Nos. 5, 6, 7, 8), globulins (Nos. 9, 10, 11), preconalbumins (Nos. 12, 13), conalbumin (No. 14) and No. 15 protein, all migrating towards the anodal end from the original (Fig. 1). Storage for 9 weeks of unoiled eggs, washed and unwashed, for 9 weeks was shown to change significantly the electrophretic pattern of albumen in comparison with that of the fresh egg. Oiling with liquid paraffin before and after washing reduced the change most siginificantiy, whereas oiling before washing had greater effect in the reduction of the change than oiling after washing (Fig. 2).

View full abstract

White Leghorn hen's eggs were coated with corn oil, liquid paraffin and 5% polymaltotriose solution, and stored for 11 weeks at 25°C. The following measurements of albumen height, Haugh units, weight loss, pH of albumen, incidences of eggs with collasped yolk and of rotten eggs, and polyacrylamide-gel disc electrophoretograms of albumen were made on the 1, 3, 5, 7, 9 and 11 week of the storage. Coating with corn oil and liquid paraffin resulted in significantly a higher interior egg qualities such as scores of albumen hight, Haugh units, albumen pH, numbers of collasped yolk and rotten eggs and electrophoretic patterns, than those of polymaltotriose coated eggs and uncoated eggs through the storage period of this experiment.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

Experiments were conducted to study the effect of feed restriction during rearing and laying periods upon subsequent performance in Lehorn-type breeder pullets, using 313 pure line hatched in April. The following three groups of different feeding programs were tested: (1) skip-a-day feeding (feed was offered ad lib. 9 hours per 48 hours) from 22 to 147 days of age and then full-fed until termination of experiments (450 days of age), (2) full-fed during the whole period of experiment (control), and (3) restricted to 90% of control during the whole period.
The rate of raising in the 90%-fed group (97.4%) was higher than that in the other two groups (93.3% in Group 1, and 95.7% in Group 2), although no statistically significant difference was observed among the three groups.
The livability in the full-fed group (90.0%) was lower than that in the other two groups of feed restriction (92.0% in Group 1, and 96.0% in Group 3), though the difference was not statistically significant.
Hen-day egg production was 67.2% in the skip-a-day group, 70.5% in the full-fed group, and 73.9% in the 90%-fed group, respectively. This indicates that the egg production was not influenced by a 10 percent reduction of feed consumption during the laying period, whereas the body weight was reduced significantly.
Feed conversion ratio in the 90%-fed group (2.35) was lower than in the other two groups (2.71 in Group 1, and 2.67 in Group 2), i.e., feed efficiency was improved by the restricted feeding in the laying period.
Fertility was higher in the 90%-fed group (94.8%) than in the other two groups (89.3% in Group 1, and 92.3% in Group 2).
The results indicate that the restriction of feed to 90% of full-fed amount improves the performance of layer breeder pullets.

View full abstract