Utilization of Leucaena leucocephala de Wit, a tropical origin perennial, as feed has been promoted, but toxicity of the mimosine in it, one of the free amino acids found in the plant, has been a serious problem in usage promotion. In a series of studies to get the basic information required for utilizing this plant as feed, the mimosine content of each segment was determined using a conventional method, and we have developed a new method to isolate and purify mimosine from its seeds through a procedure which is simpler than the conventional one. To identify the physiological activity of the mimosine thus prepared, its effects on body weight, feed intake and pelage growth of mice (Jcl-ICR) were investigated. The results obtained were: 1) The average mimosine content of the plant was about 3.6%, while segments with an active growth showed a higher value. 2) Sixty percent of the total free amino acids extracted was found to be mimosine. 3) The hot water extract of about 50g of the seeds was deproteinized, concentrated and repeatedly crystallized to obtain needle shaped mimosine. The yield was approximately 0.95g. These crystals were identified to be pure mimosine on thin-layer chromatography, UV spectrum, IR spectrum and amino acid analysis, using a commercially available mimosine as a standard. 4) The mice were fed with rations containing 0.5%, 1.0% or 2.0% mimosine. With anincrease in mimosine level, the animal body weight was reduced, and mimosine administration of more than 0.5% was considered to result in feed intake inhibition. 5) With increased mimosine concentration in rations, the pelage growth of the mice also considerably decreased. From these results, the isolated and purified mimosine was identified as the same substance as the commercially available mimosine on the basis of the chemical data and physiological activities observed.

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To estimate genetic parameters, lactation records were collected from 1968 through 1977 on 1454 Advanced Registry (AR) Holstein cows, which were the female offspring of 18 sires. Traits analyzed were milk yield, fat percent, fat yield, withers height, and body weight. The method of analysis of variance was based on Method III of HENDERSON (1953). The mathematical model was Y_ijlkmn=μ+s_i+A_j+(sA)_ij+R_k+Y_l+S_m+(RS)_km+e_ijklmn, where Y_ijklmn was each record, and μ, s_i, A_j, (sA)_ij, R_k, Y_l, S_m, (RS)_km, and e_ijklmn were the overall mean, the effect of the i^th sire (random), the effect of the j^th age at calving (fixed), the effect of the interaction between the sire and the age (random), the effect of the k^th region (fixed), the effect of the l^th year (fixed), the effect of the m^th season of calving (fixed), the effect of the interaction between the region and the season (fixed), and the special effect for each individual, respectively. The calculation was done using the computer program, LSML76, developed by HARVEY (1976). The results were as follows: 1) The effects of interaction between the sire and age were significant in milk yield, fat yield and body weight, and region effects were significant in all five traits. The linear regression of the age effect was significant on milk yield, fat yield, and body weight. The withers height was curvilinear. 2) The overall means of the milk yield, fat percent, fat yield, withers height, and body weight were 6, 825kg, 3.57%, 243.5kg, 138.9cm, and 627.7kg, respectively. Mean Separation of nine regions in milk yield gave two groups: low yielding in eastern Japan and high yielding in the West. 3) Heritabilities estimated from paternal half-sib correlations were 0.059, 0.420, and 0.070 for milk yield, fat percent, and fat yield; 0.572 and 0.128 for withers height and body weight, respectively. The estimates for milk yield and fat yield were less than 0.1. 4) Genetic correlation estimates between milk yield and fat percent, milk yield and fat yield, fat percent and fat yield were -0.35, 0.52, 0.62, respectively. The estimates between body weight and milk yield, body weight and fat percent were very large, -0.72, 0.59, respectively.

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The experiment was to study the effects of thyroidectomy (TX) and thyroparathyroidectomy (TPTX) on serum concentrations and urinary excretions of calcium and phosphorus in sheep. There were no obvious changes in serum calcium and phosphorus concentrations after TXed operation. Serum calcium and hydroxyproline concentrations decreased 2nd day after TPTX and recovered 1 week after. Since there was a close relationship between serum calcium concentrations and serum hydroxyproline, it could be considered that a deficiency of parathyroid hormone reduced serum calcium concentrations through the decrease of bone resorption in sheep. The recovery of serum calcium and hydroxyproline concentrations might be dependent on an adaptation against the long term deficiency of parathyroid hormone, that is, the activation of vitamine D3 induced by low serum phosphorus concentrations. Serum phosphorus concentrations continued to decrease after TPTXed surgery. A deficiency of parathyroid hormone might result in the lowering of serum phosphorus concentrations. Urinary calcium excretion in TXed sheep had a trend to be higher than in intact sheep. TPTXed animals excreted more calcium via urine than TXed sheep. Urinary phosphorus excretion were much lower in TXed sheep when compared to intact and TPTXed sheep. These results indicated that a calcitonin deficiency brought about the promotion of urinary calcium excretion and the reduction of urinary phosphorus excretion and a parathyroid hormone deficiency enhanced urinary calcium loss in sheep.

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A theoretical framework for estimating effects of repeated selection was extended to estimate the effect of repeated selection on genetic correlation. Sixteen generations of computer selection experiments were undertaken for nine combinations of three levels each of initial heritability and genetic correlation on the basis of some assumptions. The higher initial heritability and initial genetic correlation, the larger direct and correlated selection responses were. The genetical regression coefficient of correlated character on selected character, bG₂/G₁, was not affected by selection because of the parallelism of the truncation plane with the G₂ axis, while genetic correlation decreased with generation of selection. The stability of genetical regression maintains the validity of the current equation for estimating correlated response
ΔG₂=bG₂/G₁•ΔG₁.
On the other hand, genetical regression of G₁ on G₂ showed an increasing curvilinearity with generation of selection. An idea to deal with curvilinear genetical regression was suggested. A correction on the assumed mating system in the previous studies was made. Jpn. J. Zootech.

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β-N-Acetylhexosaminidase (E. C.3.2.1.52, NAHase) was purified from hen oviduct and properties of two forms of the enzyme (NAHase A and B) were compared. Although molecular weights of NAHase A and B were different each other when measured using Ferguson plot technique, both were exactly the same when measured using gel filtration. Their ¹²⁵I labeled tryptic peptide maps were very similar and their antigen determinants were identical. In the SDS-polyacrylamide gel electrophoretic patterns of NAHase A and B, only one protein band was present. The molecular weight of this protein band was estimated to be 5.3×10⁴. All these results seem to show that NAHase A and B are composed of the similar subunit of which protein moiety is almost the same.

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The present investigation was carried out on the seasonal changes in the home range and the size of harem groups of Misaki horses in relation to the vegetation condition. Observations were made twice a month during the period from January, 1979 to December, 1981. in the breeding season, almost all harem groups usually lived with each group together on the grasslands covered with many kinds of grasses which were rich in both quality and quantity. After September when the grasslands tended to decrease in grass productivity, most of them generally separated into numerous, comparatively small groups based upon the strong social attachment; harem group consisting of one stallion and 2-3 particular mares or family group of one more and her offsprings, and transferred from the grasslands to the particular winter home range of their own in the forests or in the weedy grasslands, in which native grasses, forbs or trees were available for them during winter. No evidence of territorial behaviour was observed in Misaki horses during the study period, and the home ranges of different harem groups showed a great degree of overlap, especially in the breeding season.

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The effect of formic acid added in pickle in the tanning using the recycled spent chrome liquor was determined. Formic acid added in pickle was transfered to the chrome liquor through the pickled skin, and accumulated in the recycled spent chrome liquor to mask the chromium complex during nine runs of tanning gradually. By cation exchange chromatography and paper electrophoresis, it was shown that the electric charge of these chromium compounds in the recycling of spent chrome liquor tended to nonionic charge from cationic one. However, the masking with formic acid did not make a highly masked complex that would cause trouble for leather-making with recycled spent chrome liquor. Moreover, there was no significant effect on the quality of resultant leather in this system.

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Genetic analysis of mouse tear protein system-1, tentatively designated Mtp-1, was studied by mating experiments. This protein was detected by polyacrylamide gel electrophoresis in region II. Sexual differences among these tear proteins in regions I, III, IV and V were also studied using Tfm (testicular feminization) mice which lacked testosterone receptors congenitally. Among the twenty inbred strains of mice examined, the F-type was observed in 8 strains (CBA/N, C3H/He, C57BL/6, IC/Le, KK, SWM/Ms, WB/Re and WC/Re); the S-type, in 6 strains (C57L, DBA/1, DBA/2, NZB, NZW and SM/J); and the O-type, in 6 strains (A/He, AKR, BALB/c, CL/Fr, DDD and NC). The phenotypes of Mtp-1 in the F1 of F×S, F×O and S×O crosses were expressed as FS, F and S, respectively. The genotypes of Mtp-1 were assumed to consist of 6 types, i. e., FF, SS, OO, FS, FO and SO. The results obtained from F₁, F₂ and back-crossing revealed that Mtp-1^F and Mtp-1^S are codominant autosomal genes allelic to recessive gene Mtp-1^O. The electrophoretic patterns of tear proteins in Tfm mice (Tfm/Y) revealcd that these proteins in the I, III, IV and V regions were of the female type, with Mtp-1 type F. Testosterone treatments caused no effect. It might be considered that the sex differences in mouse tear proteins could be due to differences in the ability to assimilate protein through testosterone receptors.

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Thirty five cows with an average age of 5. 6 years were pastured in two different public Experimental Stations from spring to autumn and reared indoors on supplemental commercial formula feed throughout winter. Samples of grass, blood and hair were collected at the beginning and end of the grazing period to investigate the effect of grazing on the nutritional status of selenium (Se) in cows. Se content of mixed pasture showed fairly low values ranging from 0. 019ppm to 0. 032ppm. No apparent difference in Se content was observed according to sampling site, species and season. Values of either blood or hair Se concentration were significantly (P<0.01) lower in autumn than in spring but were still all within the normal range according to that previously reported for Se deficient animals. The increase in serum enzymes, GOT and LDH, was not as great as that reported in nutritional muscular dystrophic animals. It was considered that the Se status of cows grazed in summer season may be free from deficiency, though it becomes fairly low during pasturing.

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