In the previous papers, we reported that administration of estrogenic substances in herbage affected on the organ weight and body composition of the hamster. The present experiment was conducted to determine the regression on time of the organ weight and body composition in both intact male and spayed hamsters after oral administration of estrogenic substances in herbage. The results were summarized as follows: 1) Administration of diethylstilbestrol (DES), genistin and alfalfa-extract, which were adjusted to the potency of about 0.01, ag of DES per one gram of the basal diet, improved the body weight gain and feed efficiency in both of the animals. 2) In the case of male hamsters, DES, genistin and alfalfaextract increased regression on time of the body length, femur length, kidney weight, liver weight and contents of water, fat and fat-free solid. Genistin and alfalfa-extract increased regression on time of the spleen weight, seminal vesicles weight and testes weight, and gave no effect on that of the adrenal weight. On the other hand, DES decreased regression on time of the adrenal weight, seminal vesicles weight and testes weight, and gave no effect on that of the spleen weight. 3) In the case of spayed hamsters, DES, genistin and alfalfa-extract increased regression on time of the body length, femur length, kidney weight and contents of water, fat and fat-free solid. Regression on time of the adrenals weight was not affected by these estrogens. Each estrogen used gave different regression on time of the kidney weight and spleen weight.

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It is the purpose of this study to make a statistical study of the duration of gestation in horses. The data of 954 gestation periods of 192 mares having more than three foalings at the Tokachi Livestock-Breeding Station in Hokkaido from 1948 to 1972 were analyzed. The results were as follows. 1. The mean duration of the gestation in this case was 334.7 days with a range of 286 to 371 days. 2. An analysis of the environmental factors of variation in the duration of the gestation was carried out. From these results, a statistically significant variation was found in individual mares, month of foaling, and in breeds of the Arab and Breton(P≤0.05).3. The rejection limit and confidence limit for the effects of month of foaling, breeds and sex of foetus were calculated, with the range being 307.9-363.5 and 326.4-343.5 day srespectively(P≤0.01).4. From the analysis of variance using a two-fold hierarchial classification, heritability was estimated as 4σD2/σs2+σD2+σd2 (paternal half sib). 4σs2/σs2+σD2+σe2 (maternal half sib) 2(σs2+σD2)/σs2+σD2+σe2 (full sib).The heritability estimated from the records is 0.24, 0.97 and 0.60 respectively.

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The five kinds of bacteria, i. e. Bacteroides sp., Escherichia coli, Lactobaci-llus sp., Staphylococcus epidermidis and Streptococcus faecalis were monocontaminated to germfree (GF) mice at the age of eight weeks, and digestion and absorption of nutrients in diet and nitrogen (N) retention were compared in the same mice before and after contamination. The animals used were both sexes of the ICR strain of GF mice reared in metabolism cage (5 mice per cage) from 7 to 11 weeks of age. The results may be summarized as follows: 1) Body weight, food intake and fresh feces excretion were not influences by bacteria monocontamination (MC). 2) Viable counts of fecal bacteria two weeks after MC were stabilized. 3) Apparent digestibility of crude or true protein and crude fat, generally decreased slightly after MC except in a few examples. 4) N retention increased markedly only after Staphylococcus epidermidis MC among the five kinds of bacteria tested. 5) The protein N ratio in feces tends to increase by MC. As a conclusion, among the five kinds of bacteria Staphylococcus epidermidis has a beneficial effect on utilization of N in the digestive tract of the host mice.

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Five kinds of bacteria i.e. Bacteroides sp., Escherichia coli, Lactobacillus sp., Staphylococcus epidermidis and Streptococcus faecalis were administered (polycon-tamination: PC) in combinations in mixtures of two, three, four and five kinds for establishment in the intestinal tracts of 8-week-old germfree (GF) mice. The effects of these combinations of bacteria on digestion and absorption of nutrients in diet and nitrogen (N) retention were investigated by comparison before and after contamination in the same mice. The animals were both sexes of the ICR strain of GF mice reared in metabolism cage (5 mice per cage) for four weeks from 7 to 11 weeks of age. The results can be summarized as follows; 1) Body weight, food intake and fresh feces excretion increased slightly for all combinations of bacteria, but among the combinations of bacteria no significant difference were found. 2) Viable counts of fecal bacteria two weeks after PC were <103 of Staphylococcus when coexisted with the other four kinds of bacteria, but remained constant in all other cases. 3) The apparent digestibility of crude and true protein in general slightly decreased by PC, but in a few cases where Staphylococcus was present, there was a slight increase. 4) The apparent digestibility of crude fat generally slightly decreased by PC. 5) The tendency showed increasing N retention when Staphylococcus epidermidis was present and sufficiently established in the digestive tract of the PC mice, in most combinations.

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Ten Japanese Shorthorn steers (S) and ten Japanese Black (B) steers were used to compare the growth and carcass characteristics under high (group A) and low-medium (group B) planes of nutrition. S steers gained significantly faster than B steers in both groups and relative gain of B steers to that of S steers was less under lower planes of nutrition. Dry matter intake per unit of live weight was larger for S steers in group A, but no breed difference was found in group B. Feed conversion ratio was not different between the two breeds in group A, but in group B difference was found in favor of S steers. There was neither breed nor group difference in dressing percentage and no substantial difference was found in the percentages of edible portion and bone in the carcass. Most of the organ weights per unit of live weight were larger for S steers except for those of head and hide. Subcutaneous fat was thicker in S steers, but the weight of intraperitoneal fat was greater in B steers. There was a positive correlation between the fat content in rib-eye muscle and the amount of peritoneal fat, the latter given as a percentage of live weight at slaughter, but there was no such correlation between the fat content of rib-eye muscle and subcutaneous fat thickness.

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Effect of the inoculation of L. plantarum to improve silage quality was investigated with and without 1%glucose addition at two ensilage temperatures(30°and 15°). Without the inoculation, higher temperature showed adverse effect on the silage quality, and glucose addition resulted in excellent quality irrespective of the temperature. L. Plantarum strain which was capable of rapid and extensive lactic acid production both in tryptone-yeast extract-glucose broth and in grass extract was selected for the experiment. The inoculation of this test strain had no beneficial effect, producing similar quality silage to the corresponding one, whether it was good, medium or poor quality.

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