The two experiments were carried out to study the effect of vitamin B₁₂ on the growth rate of chick, and the egg production and the hatchability of laying hen.
(1) White leghorn hens were fed either low vitamin B₁₂ layer diet, which consists of corn starch, meal and soybean oil, or high vitamin B₁₂ layer diet, which was enriched with 10μ of vitamiu B₁₂ per kg of the low vitamin B₁₂ layer diet.
The efficiency of vitamin B₁₂ had no influence on egg production, egg weight, feed consumption and viability of the hens. Moreover, no difference in hatchability was observed between the fertile eggs of hens on low vitamin B₁₂ diet and that on high vitamin B₁₂ diet, although vitamin B₁₂ content in the former was much low than that in the latter.
(2) The additional effect of vitamin B₁₂ (10μg/kg) and DL-methionine (0.4%) to the low vitamin B₁₂ and low methionine starter diet was examined on the growth rate of the chicks, which were offsprings of breeding hens fed either low vitamin B₁₂ layer diet or high vitamin B₁₂ layer diet.
Additional vitamin B₁₂ to both of low vitamin B₁₂ layer and starter diets was effective to improve growth rate of the chicks. The additional effect of methionine on the chick growth was significant, although the interaction between vitamin B₁₂ and methionine on the growth rate of chick was not recognized. The feed conversion was improved by addition of either vitamin B₁₂ or methionine to low vitamin B₁₂, low methionine starter diet. Possitive correlation was observed between the amount of vitamin B₁₂ in the chick liver and growth rate of chick.

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Two experiments with 103 White Leghorn laying hens and one experiment with 95 female meat-type growing chicks were carried out. To these hens and chicks, one of 6 experimental diets containing crude protein from 16 to 28% and total digestible nutrients from 60 to 73% was fed for 18 days to 9 weeks. The birds were sacrificed on the schedule to determine abdominal fat content. Carcass fat content of part of them was also determined.
Linear relationship between abdominal fat content (x%) and carcass fat content (y%) was observed, which can be well described by the following Equation 2.
y=5.03+3.04x....(2)
With this equation, carcass fat content, laborious to determine, can be estimated by abdominal fat content with high reliability.
The decrease in dietary energy levels from 73% to 60% was effective to decrease abdominal fat content of both of laying hens and growing chicks. In agreement with the previous observations, the increase in dietary protein levels from 16% to 22 or 28% was effective to decrease abdominal fat content of growing chicks. However, in striking contrast, dietary protein levels had little effect on abdominal fat content of laying hens, suggesting the difference in protein or fat metabolism between laying hens and growing chick.

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Two experiments were conducted to determine the effect of dietary calcium excess during growth on the performance of chickens. In Experiment 1, 8 diets of two levels of available phosphorus and four levels of calcium were fed growing chickens during 4-20 weeks of age. Dietary available phosphorus levels were 0.4% (normal) and 0.6%, and calcium levels were 0.75 (normal), 1.75, 2.75 and 3.75%, respectively. In Experiment 2, 6 diets of 6 calcium levels (0.75, 2.25, 2.75, 3.25, 3.75 and 4.25%) with normal available phosphorus level (0.4%) were fed growing chickens during 10-20 weeks of age. After 20 weeks old, conventional laying diet (calcium 2.75%) were fed all the pullets.
The results were as follows.
1. The pullets fed diets containing 2.75% calcium or above with normal phosphorus level during growing period (4-20 and 10-20 weeks of age) showed significantly lowered growth and feed efficiency compared with normal growing diet (available phosphorus 0.4% and calcium 0.75%). Adverse effect of growth and feed efficiency by dietary calcium excess disappeared with increasing dietary phosphorus level.
2. Sexual maturity, egg production, egg weight and feed efficiency during laying period, were not significantly affected by dietary calcium and phosphorus levels in growing period.
3. About 1/4 of the pullets fed the diet containing 3.75% calcium and 0.4% available phosphorus during 4-20 weeks of age, died of kidney damage (kidney enlargement and uric acid deposition on kidney, liver and heart).
It may be concluded that feeding high calcium diets containing 2.75% (standard calcium level of conventional laying diet) or above to growing chickens must be avoided. Also it was shown that adverse effect of dietary calcium excess was eliminated by the addition of phosphorus to the diet.

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Four experimental diets containing 75, 65 (standard), 55 and 45% TDN (total digestible nutrients) were fed White Leghorn growing pullets (10-20 weeks of age). Protein level was about 15% in all the experimental diets. After 20 weeks old, the conventional laying ration was fed all the pullets.
The results were as follows.
1. Body weight gain during 10-20 weeks of age decreased as the TDN level decreased. Body weight gain of the pullets fed TDN 45% ration was 61% of that fed TDN 65% ration. As dietary TDN level increased, feed consumption and feed efficiency decreased, and nitrogen retention increased.
2. Sexual maturity of pullets fed lowest energy diet (TDN 45%) delayed about 10 days compared with pullets fed control diet, but subsequent laying performance was not affected by the dietary energy levels during growing period.
3. It was shown that the feeding of low energy ration to the growing chickens (10-20 weeks of age) significantly restricted the growth, but did not improve egg production and other laying performance. Also, the pullets fed lower energy ration consumed much feed and decreased feed efficiency, and increased feed cost.

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To obtain quantitative information on the feeding actitvity of chickens, an apparatus for the continuous measurement of diurnal changes in feed intake and time spent eating was developed.
The apparatus consists of three main parts: a feed trough on a spring balance, a shock absorber unit and a pen-writing clockwork recorder. The ascending motion of the feed trough on the spring balance is transmitted to the pen recorder in accordance with the decrease in amount of feed. The changes in the amount of feed eaten are thus detected from the ascending distances recorded on the chart of the recorder. The time spent eating is also detected from the length of the pecking time which is represented by the vertical vibrations on the chart.
In the application of the apparatus to adult hens, a change in weight of 1g for feed intake and a change in time of 3 minutes for time spent eating can be detected. The mean value of the errors of the measurements is 3.3g for weight and 3.6 minutes for time.
On the basis of the evidence obtained from the test, it has been confirmed that this type of apparatus should be useful for measuring the diurnal changes in feeding activity and for analyzing the feeding behavior of chickens.

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Soybean foots and rice foots are byproduct of the refining of oils for food use, which have been used for feed as dark oil after hydrolysis of sodium salts of fatty acids by sulfuric acid. The purpose of the experiments reported in this paper is to use alkaline foots themselves directly as energy source for poultry.
Availability of energy in both of soybean foots and rice foots, i. e. percentage of available energy in gross energy, estimated by bioassay procedure with 180 starting chicks for 4 weeks was excellent, being 94 and 99%, respectively. No chicks died and no abnormality was observed among the chicks fed the foots.
Nitrogen-corrected metabolizable energy of both of the foots estimated by analyses of feed and excreta was also excellent at the dietary level of foots dry matter of 3.8 and 3.0%, respectively, though metabolizable energy decreased gradually and excreta became loose with the increase in dietary foots levels.
It was concluded that alkaline foots themselves, having high calorie of 7-9kcal/g of dry matter, are excellent energy source for poultry, if their dietary level be kept lower than 3-4%.

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Low lysine diets chiefly composed of yellow corn and sesame meal were fed White Leghorn female chicks during 0-4 and 4-8 weeks of age, respectively. Lysine contents of low lysine diets fed the chicks 0-4 and 4-8 weeks old, were 0.6 and 0.4%.
The growth of chicks fed low lysine diets during 0-4 and 4-8 weeks of age, was restricted to about about 30 and 60% of control diet (yellow corn-soybean meal, lysine 1.0%). Both feed consumption and feed efficiency of chicks fed low lysine diets during 0-4 and 4-8 weeks of age, were also restricted to about 50 and 80% of control diet.
Feeding of low lysine diets during 0-4 weeks of age delayed sexual maturity about 10 days, but did not affect the subsequent egg production and egg quality.

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