Heart rate (HR) and heat production (HP) of six lactating Holstein cows were measuered simultaneously using mask method, and also mean HRs during 24 hours were measured for eleven lactating dairy cows under the feeding experiments. 1) A close relationship between HR and HP was obtained in each one of six cows. The prediction errors (PE) which were expressed as a percentage of the mean level of y for the standard deviation of y (Sy•x) were within the range of ±4.7 to ±9.1% for all of the animals. It is suggested that the HR measurements could offer a practical method of measuring HP of lactating dairy cows on free range. However, the individual differences on the regression constants still persist as shown in Table 1. 2) Eliminating the calibration of regression on each animal, the two equations which estimate HP from HR measurements on lactating dairy cows would be suggested as follows, (1) Y=-0.401+0.113X (Sb=±0.0059∗∗, r=0.89∗∗, PE=±6.900) Y: HP Kcal/W^0.75. h, X: HR beats/min, (2) Y=-0.347+6.93X (Sb=±0.366∗∗, r=0.89∗∗, PE=±7.0%, ∗∗P<0.01) Y: HP Kcal/W0.75. h, X: RHR (relative HR, RHR 1=61.3 beats/min). The better way to estimate HP from HR measurements would be to use the mean HR from 4 to 6 animals at least in order to remove the individual differences of HR. 3) The clear difference on estimated HP was observed between lactating cows and the pooled dairy bull calves and steers, but the significant difference on the regression coefficient was not observed between them. The ratio of RHR to RHP (relative HP) was nearly 1:1 in lactating dairy cows and the pooled dairy bull calves and steers.

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Surface ultrastructure of ductus deferens in 6- to 13- week-old cockerels was examined by scanning electron microscopy. The results obtained were as follows:(1) Intact cockerels. The epithelial cells of ductus deferens had luxuriant short microvilli, some long cilia and baloon-like cytoplasmic projections (apocrine projections) on their surfaces. Although the cilia showed no change in number and shape during growth, the microvilli were always abundant and gradually lengthened toward the age of 10 weeks. The apocrine projections increased both in number and in size during growth. Spermatozoa first appeared in the cavities of ductus deferens at the age of 13 weeks. Some spermatozoa attached their heads to the apocrine projections.(2) Capons. A week after castration, at the age of 7 weeks, the microvilli on the surface of the epithelial cells turned to be less in number and shorter than those of intact cockerels, but the cilia remained with no changes. The apocrine projections still remained 3 weeks after castration, though markedly decreased in number. They completely disappeared 4 weeks after castration.(3) Androgentreated capons. The microvilli re-appeared to be luxuriant only a week after androgen injection. The apocrine projections also re-appeared a week after injection, though still a few. They remarkably increased in number another week later.

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Hexokinase (ATP: Hexose 6-phosphotransferase EC 2. 7. 1. 1.) in 105, 000×g supernatant from the liver and muscle of the quail, Coturnix coturnix japonica, was examined by mean of celluloseacetate membrane (Titan III) electrophoresis. Electrophoresis was performed at 4° for 60 minutes at a constant current of 0.5mA/cm. using tris-citric acid-sodium veronal buffer containing 5mM ethylenediaminetetraacetic acid, 5mM 2-mercaptoethanol and 10mM glucose. Enzymatic development was carried out in accordance with the method descrived by SATO et al. (1969). Four isozymes were noted, designated, in order of increasing mobility, as L-1, -2, -3, and -4 for those from the liver and M-1, -2, -3, and -4 for those from the muscle. Relative ac- tivity differed between liver and muscle isozymes of each corresponding mobility level (L-1:5.8±0.8%, -2:1.2±0.3%, -3:48.4±2.3%, -4:44.6±2.2%, M-1:8.8±1.5%, -2:37.4±3.1%, -3:8.8±1.5%, -4:33.1±3.1%). Substrate concentration, substrate specificity, heat stability and activator for these isozymes were examined to characterize them. Activities of L-2, -3 and -4 were inhibited by a substrate of 300mM glucose. Glucokinase (EC 2.7.1.2.), which was recognized in Rat liver by KATZEN and SHIMKE (1965) and other authors, was not detected in quail tissues by electrophoresis. L-1, -2, M-1, -2 and -3 had high specificities for D-glucose, while L-3, -4 and M-4 reacted to four hexoses (D-glucose, D-fructose, D-mannose and Dgalactose). Difference was also seen in the effect of glucose on the heat stability of the isozymes. L-1, -2 and M-2, which had high specificities with glucose, were protected from heat inactivation (45°) by 100mM glucose. L-3 and -4 were the most heat-labile and were not stabilized by 100 mM glucose. It was recognized that 2-mercaptoethanol, L-cystein and citric acid act as activators for hexokinase. Two kinds of sulf-hydryl reagents, i. e. 2-mercaptoethanol and L-cystein, activated L-1, -2, M-1, -2 at the concentration of 5mM. Activating ability of citric acid was different among the isozymes. L-2, M-1 and -2 were greatly activated by citric acid at a concentration of 10^-5M and inhibited by it at higher concentrations. While L-4 and M-4 could not be detected where the concentration of citric acid was 10^-4M or lower, they were activated by higher concentrations of 10^-3-10-²M. These results suggest that the activity of hexokinase in quail tissue isozymes is regulated by citric acid, a metabolic substance in the TCA cycle.

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The present study was to examine the influence of feeding three different levels of dietary protein on the estrous cycle in mice. Adult virgin mice of ICR-JCL strain weighing 30.7g at 60-65 days of age and exhibiting regular estrous cycles during 14 days before experiments were used. Composition of diets and feeding conditions were almost similar to those as in our previous paper1). Protein levels in the diets were 15% crude protein (CP) (low), 25% CP (standard) and 35% CP (high). In experiment I, 90 mice in total were divided into 3 groups of 30 mice each. Three groups of mice were fed with different dietary protein levels for 21, 31 and 41 days and estrous cycle was investigated for 21 days starting from the 1st, the 11th and the 21st day of experimental feeding. In experiment II, 240 mice in total were divided into 3 groups of 80 mice each. Three groups of mice were fed with experimental diet as in the experiment I. Mating (formation of vaginal plug) was investigated starting from the 2nd, the 10th, the 20th and the 30th day of feeding with experimental diet. The results obtained are summarized as follows. 1) The duration of one estrous cycle in mice fed with either high or low protein ration, was significantly longer than that of the mice fed with standard ration, and the number of recurrent estrous cycle within three weeks decreased in the experimental mice as compared with that of the control mice. The prolonged estrous cycle in mice fed with low protein ration was due to the extention of both estrous and diestrous stages. 2) Duration from the introduction of male mice into the female mice to the detection of vaginal plug prolonged in the mice fed with either high or low protein ration as compared with that of the control mice, and this prolongation became remarkable as the feeding periods were extended. However, the vaginal plug was observed even in the experimental mice within five days after the introduction of male mice, and ovulation was also confirmed at autopsy. From the results mentioned above it was suggested that the formation of vaginal plug followed by the ovulation was induced by the stimulus from the excitation or mounting of the male. Therefore, depression in the conception rate and the prolongation of delivery interval in mice fed with high or low protein rations might be due to abnormal fertilization or the failure of implantation.

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The purpose of this paper is to compare the viscoelastic properties between breast and thigh meat in the chickens of different ages by means of stress relaxation test, and to investigate the effect of dietary fat levels on their meat. The chickens used were Cornish×White Rock raised in individual wire cages. The number of chickens used was 52 in total, and they were all females. They were divided into 3 groups, and fed with the experimental diet containing 0%, 5% and 10% soybean oil, respectively. The experimental periods were 10, 20 and 34 weeks from day-old. Just after slaughter, the breast meat (M. pectoralis profundus) and the thigh meat (M. iliotibialis) were removed. They were immediately put into polyethylene bag, and were kept at -17°C at least for 24 hours. Several pieces (50mm in length, 20mm in width and 2-4mm in thickness) were taken from each chicken meat by a microtome in such a way that long axis of each piece was parallel to the direction of muscle fibers. Then, these pieces were stamped out with a dumbell-shaped apparatus. The stress relaxation measurement of these samples was carried out with a chainomatic balance Food Rheometer (Tabai Co., Ltd.). These samples were stretched 13.5mm at a speed 2.8mm/sec and were kept for 5min in a chamber with 50±5% of relative humidity at 30±1°C. The parameters obtained from stress relaxation test were F_max (gw), τ (sec), and S/f₀(%). The following imformations were obtained. 1) F_max value was larger in thigh meat than in breast meat in each group (P<0.01), therefore, thigh meat seemed to be stronger than breast meat as to Koshi (Body). 2) τ value of chicken fed with soybean oil free diet was larger in thigh meat than in breast meat (P<0.05), the thigh meat seemed to be more elastic than the breast meat. 3) In the age of 34 weeks old, S/f0 value of chicken fed with soybean oil free diet was larger in thigh meat than in breast meat (P<0.05), therefore, the structure of the thigh meat seemed to be firmer than that of the breast meat. 4) The result of this experiment suggested that the viscoelastic properties of raw breast and thigh meat of chickens were not affected directly by the dietary fat levels. The role of intramuscular fat on chicken meat tenderness seemed to serve as secondary factor.

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In order to investigate the immuno-genetical correlation of the pig lymphocyte antigens and the major histocompatibility complex, the lymphocyte 18 of littered pigs and 51 non-littered pigs have been carried out the mixed lymphocyte culture (MLC) reaction. The results obtained were summarized: 1) the mean value of cpm count per minute by autologous cells of 18 littered pigs were 441±53 in the 1-way method 685±94 in the 2-way method. And mean value of cpm by allogeneic cells were 4174±260 in the 1-way method and 3648±403 in the 2-way method. 2) The mean value of cpm by autologous cells of 51 non-littered pigs were 522±36 in the 1-way method and 533±39 in the 2-way method. The mean of cpm by allogeneic were 7360±322 in the 1-way and 7400±561 in the 2-way method. 3) In 8 littered pigs, the identical sibling groups of SLA antigens were No. 3-No. 7 and No. 5-No. 8. The resembling groups of histocompatibility antigens were No. 1-No. 6-No. 8 and No. 2-No. 3-No. 4-No. 5-No. 7. Therefore, the histocompatibility antigens by MLC could not be always agreement with the SLA antigens.

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The distribution and activity of nicotinamide-adenine dinucleotide phosphate (NADP)-dependent glucose-6-phosphate dehydrogenase (G-6-PDH) in the goat ovary were examined histochemically. Tokara goats on Day 5 of the estrous cycle and on Day 5 of the pregnancy were used. The G-6-PDH activity was determined by the slightly modified method of NACHLAS et al. Both the nonpregnant goat ovary and the early pregnant goat ovary showed a similar distribution and activity of this enzyme. In the normal preantral follicles, the granulosa cells exhibited moderate enzyme activity and the theca cells very weak. In the normal antral follicles, enzyme activity was strong in the granulosa cells, and was very strong in the theca interns but weak in the theca externa. The corpora lutes showed a very strong enzyme activity. These histochemical observations suggest that the granulosa cells and theca interns of the normal antral follicles and the corpora lutea in the goat ovary are likely to contribute to steroidogenesis. A weak or very weak enzyme activity in atretic follicles, ovarian stroma and germinal epithelium suggests that they are not active in steroidogenesis.

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In order to investigate the metabolic use of VFAs in cold-exposed sheep liver, fifteen Merlno sheep were repeatedly exposed to an ambient temperature of 2°C, On the 1st, 4th and 7th day of cold exposure, ¹⁴C incorporation from ¹⁴C acetate, propionate and butyrate into CO₂, glucose, ketone bodies, cholesterol ester, triglyceride, free cholesterol, NEFA and phospholipid in the liver slices were observed. 14C incorporation from ¹⁴C-acetate into CO₂, glucose, ketone bodies tended to increase and into cholesterol ester, triglyceride, free cholesterol, NEFA tended to decrease on the 1st, 4th or 7th day of cold exposure, but, was changed to decrease into ketone bodies on the 4th day. ¹⁴C incorporation from ¹⁴C-propionate into CO₂, glucose, triglyceride, NEFA, phospholipid tended to increase and into cholesterol ester, free cholesterol tended to decrease on the 1st or 4th day of cold exposure, but was changed to increase into free cholesterol on the 4th day. ¹⁴C incorporation from ¹⁴C-butyrate into CO₂, glucose, ketone bodies, triglyceride, free cholesterol, NEFA, phospholipid tended to increase and into cholesterol ester tended to decrease on the 1st, 4th or 7th day of clod exposure, but, was changed to increase into cholesterol ester on the 4th day. The results of this experiment indicated that VFAs could be used in various metabolic purpose on cold exposure in sheep liver slices. Further, it was also indicated that each VFA showed their own characteristic ways of metabolic use in such a case of this experiment.

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Superovulated mouse oocytes were fertilized in vitro with pre-incubated cauda epididymal spermatozoa, and the process of sperm penetration through the zona pellucida was studied by scanning electron microscopy. By 5min after insemination, the spermatozoa had passed through the cumulus oophorus, reached the surface of the zona pellucida and had begun to penetrate the zona pellucida. Spermatozoa in the act of penetrating the zona pellucida were frequently found in the oocytes fixed 11min after insemination. The sperm penetration through the zona pellucida was completed within 20min in most oocytes leaving 'sperm penetration hole' on the zona pellucida. The sperm penetration holes were not completely repaired by 4hr after insemination.

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