The effects of processing methods and cholesterol addition on the nutritive value of LPCs prepared from alfalfa, Italian ryegrass and ladino clover were studied in chicks. Each LPC fortified with methionine was used as a sole protein source, providing 10% protein in the diet.
The washing by ethanol of thermally-treated coagulum obtained from alfalfa was effective in reducing the medicagenic acid content and improving the nutritive value, whereas this treatment had little effect on the nutritive value of Italian ryegrass and ladino clover LPCs.
The adjustment of the alfalfa extract to pH 8 by NaOH had little effect on the medicagenic acid content but significantly improved the nutritive value although it was still inferior to the nutritive value of the ethanol-treated LPC.
The heated and NaOH-treated alfalfa LPCs high in the medicagenic acid content had a hypocholesterolemic effect. The addition of 1.0% cholesterol was as effective as the ethanol treatment in improving the nutritive value of the heated and NaOH-treated alfalfa LPCs.
The nutritive value of alfalfa and Italian ryegrass LPCs coagulated by anaerobic fermen-tation of the extract for 7 days was much lower than that of the thermally-treated LPCs. In the case of the fermented alfalfa LPC, the accumulation of medicagenic acid was observed and the cholesterol addition was not so effective.
This work was supported by a grant-in-aid for Co-operative Research No. 59360036 from the Ministry of Education, Science and Culture in Japan.

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The changes in the concentrations of various plasma and liver lipid fractions, plasma E₂ and corticosterone, and hepatic lipogenic related enzyme (LRE) activities, were determined. The relationships between the concentrations of these plasma hormones and hepatic lipoge-nesis around the onset of egg production were elucidated.
E₂ concentration rose gradually as the hens advanced in age, reaching a peak at the age of 150 days which was the period immediately before the onset of egg laying. Triglyceride, NEFA, total cholesterol and phospholipid levels in the plasma remained relatively constant between 90 and 140 days of age. These rose rapidly as the birds neared the age of 150 days, and reached their peaks immediately before the onset of laying. These values decre-ased, and then remained stable, upon the onset of egg production; nevertheless, even at their reduced levels, they were still comparatively higher than these obtained during the 90-140 days of pre-ovulation period.
Hepatic triglyceride content rose gradually and simulataneously with the aging of the hens and reached a peak immediately before the onset of laying. It decreased when the egg laying set in, but remained at a relatively higher level thereafter.
The activities of hepatic LREs increased gradually as the hens advanced in age. Fatty acid synthetase reached a peak at 130 days of age and citrate cleavage enzyme and NADP-malate dehydro-genase, 140 days of age.
Statistically significant positive correlations were observed between plasma E₂ concentra-tion and the grouped parameters of abdominal fat weight (P<0.01), hepatic triglyceride content (P<0.01), concentrations of various plasma lipid fractions (P<0.01), and activities of fatty acid synthetase (P<0.05), NADP-malate dehydrogenase (P<0.05) and citrate cle-avage enzyme (P<0.05) in the liver of hens.

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Progesterone in Silastic tubing (Pt) was implanted subcutaneously 1.5hr after the second (C₂) ovulation of the sequence in the hen and effects of Pt treatment on subsequent ovula-tion and plasma concentrations of LH, progesterone (P₄), testosterone (T) and estradiol (E₂) were studied. Plasma concentrations of P₄ increased rapidly about 5-fold and remained high throughout 45hr after Pt implantation. LH levels also significantly increased (1.4-fold) 4hr after Pt treatment but declined thereafter to levels below the pretreatment levels. T and E₂ levels showed changes similar to LH levels but significant changes were detected only at 45 hr after the treatment. This treatment resulted in delayed ovulation for more than 41 hr. To examine the responsiveness of the hypothalamo-anterior pituitary-ovarian axis in those hens either ovine LH (100μg), synthetic [Arg8]-LHRH (25μg) or P₄ (1.0mg) was injected at 45hr after Pt implantation. Both LH and LHRH injections induced ovulations at the rate of 70 and 80%, respectively. Conversely, P₄ injection (after Pt treatment) failed in induc-ing ovulation in the majority of hens examined (ovulation, 27%). The same of ovine LH, LHRH and P₄ induced ovulations at the rates of 70, 80 and 75%, respectively, when they were injected 13.5hr after C₂ ovulation in hens without Pt treatment. These results sug-gest that exogenous Pt may exert its inhibitory effect on the hypothalamus or other regions of the CNS implicated with regulation of the preovulatory LH release. The ovulation-induc-tion time in hens pretreated with Pt was shorter in response to LH (6.0hr) or LHRH (4.7 hr) injection when compared to hens without Pt treatment (8.8hr). This was reflected upon higher concentrations of plasma P₄ in Pt-treated hens.

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Two experiments were carried out to prevent decreasing egg weight of specific patho-gen free (SPF) chickens maintained as a closed flock. Hatching eggs were divided into four groups, S (45-50g), M (51-55g), ML (56-60g), L (61-65g) size, respectively.
In Exp. I, SPF chicks hatched from the eggs grouped were raised. Egg weight pro-duced from the pullets were measured from 21 to 43 weeks of age. After 25 weeks of age, mean egg weight of the pullets hatched from ML and L size eggs was significantly greater than that of the pullets hatched from S and M size eggs. Significant differences, however, were not observed between ML and L size egg groups and between S and M size egg groups.
In Exp. II, SPF chickens of fourth generation of two strains (O•GO and GO•OG) were produced from M size eggs of third generation chickens. Fifth generation chickens of the strains also produced from ML and L size eggs of chickens of fourth generation.The chickens of fifth generation of both strains produced more number of ML and L size eggs than the chickens of fourth generation, respectively. Egg production, fertility and hatchability of eggs produced from chickens of fourth and fifth generations of both strains were not different from them of chickens of third or earlier generations, respectively.
From these results, it was suggested that selection of hatching egg weight might be effective for prevention of decreasing egg weight caused by replacement of generations of SPF chickens maintained as a closed flock.

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The rates of B antigen positive (B+), T antigen positive (T+) and surface Ig positive (sIg+) lymphocytes in the bursa of Fabricius, thymus and spleen were determined following after cyclophosphamide and cortisone acetate injection. The amounts of antibody-conju-gated FITC bound to bursacytes were also determined to estimate the epitope density of B antigen and slg after cyclophosphamide injection. Cyclophosphamide induced significant decreases in positive ratio of B+, sIg+ and sIgM+ lymphocytes in the Bursa to approximately the same extent. Epitope density of slg on bursacyte also reduced by cyclophosphamide injection. In the spleen, the rates of B+ and sIg+ lymphocytes decreased, while cyclophosphamide failed to induce any changes in cellular composition of the thymus. From these observations, it is supposed that cyclophosphamide exerts its action on mature bursacytes, B+sIgM+, B+sIgG cells and peripheral B lymphocytes, and then, blocks their proliferation. Although cortisone acetate caused loss in weights of the Bursa and thymus, no any changes in the rates of B+, sIg+, sIgM bursacytes and T+ thymocytes were observed, On the other hand, cortisone acetate induced increase in the rate of B+ cells and decrease of T+ cells in the spleen. These results suggest that cortisone acts upon all of lymphocytes existed in the Bursa and thymus and exerts its direct action on these cells. It is also suggested that cortisone acts on thymocytes severer than on bursacytes.

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In order to investigate the mechanism of incidence of egg breakage in cages, a simu-lation experiment of laying was carried out. Five sound eggs were put at the front of the cage floor and a sound egg was dropped at the rear of the cage floor. Eggs were collided with each other and then the eggs were candled. The interval between parallel wire of the cage flloor tested was 20, 24 and 25mm and the slope of the cage floor was altered. The manner in rolling down of eggs was observed using the cage floor with the interval of 22.7mm between parallel wire at the slope of 8°⋅ Ca and P content in the feed supplied were 3.5% and 0.77%, respectively.
The ratio of eggs rolled with the minor axis to eggs rolled with the major axis was 6 to 4. Egg breakage was observed one of the pair of eggs collided which has thinner shell. But when egg rolled with the minor axis egg breakage tended to be observed in rolling egg, and when egg rolled with the major axis egg breakage tended to be observed in egg collided. Incidence of egg breakage tended to increase in the cage with narrower interval between parallel wire and steeper slope of the cage floor. Fifty three eggs in 60 trials were broken in case of using the cage floor of 20mm×7° and seven eggs in 60 trials were broken in case of using the cage floor of 25mm×4°.

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