In order to study relations between marbling scores and physical and chemical properties of commercial beef and to consider an objective evaluation of a meat quality, samples were obtained from standardized retail cuts of 6-8 rib thoracis portions of Japanese Black and Holstein steers. They were analyzed for specific gravity, crude fat, moisture, crude protein contents and fatty acid composition. The average of fat contents of samples in special selection, choice, 1st grade, 2nd grade and 3rd grade of Japanese Black steers were 31.7, 23.5, 19.8, 14.9 and 10.6%, respectively and those in 1st grade, 2nd grade and 3rd grade of Holstein steers were 12.4, 7.7 and 8.5%, respectively. There was a significant difference in the fat content between the special selection and the other grades (P<0.01). There is a highly positive correlation between the fat content and marbling score in both samples of Japanese Black and Holstein steers. There was no statistically significant difference in the fat content of the marbling scores "+1" and "+2" on the both breeds. There was significant difference in the fat content between the marbling scores among the grades except between the mabrling scores "+2" and "+3" (P<0.05). There was a highly negative correlation between the specific gravity and fat percentage of meat on the both breeds. A linear equation to estimate a fat percentage of meat from a specific gravity is obtained as follows: y (fat percentage of meat) =-549x (specific gravity)+592, r=-0.93. A linear equation to estimate a marbling score from a specific gravity is caluculated follows: y (marbling score)=-96.6x (specific gravity)+103, r=-0.92. From these equations, fat percentage and marbling score can be easily estimated from a measurement of specific gravity of beef meat. There was a significant difference in C 18:1, total saturated and unsaturated fatty acids contents among the both breeds. There was a positive correlation between the fat percentage and C 18:1, and total unsaturated fatty acids.

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4 Holstein calves were used in order to investigate the effect of high dietary potassium on the organs. 2 calves were fed on a conventional hay diet as a control group and 2 calves fed on a high potassium hay diet as an experimental group. The results were as follows: 1) Reddish purple spots were observed on the renal surface of calves in the experimental group. The surface membrane was not able to peel easely and small blood spots was observed. The blood spots was observed similarly on the mucous membrane of the bladder. 2) Potassium contents of the kidney of calves in the experimental group was higher than that in the control group. On the contrary, sodium contents of the heart, kidney, pancreas and thymus of calves in the experimental group were lower than those in the control group. 3) Light microscopic observations revealed that the features of the kidneys of the experimental group did not differ from those the control one. Adrenocortical cell of the experimental group contained a large number of granules which were stained with eosin, azocarmine and acid fuchsin.

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Various raboratory methods for predicting TDN contents were tested and compared on 19 samples of grass or mixed hay and 7 alfalfa hay. For all samples TDN contents in vivo were determined with sheep or goat fed at a maintenance level. The methods investigated were Weende component (crude fiber), cell wall components (detergent analysis and enzymatic analysis), summative equation (enzymatic analysis) and Adams method. Considerably better results were obtained with method using various fractions determined by enzymatic analysis.

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To investigate the effect of soluble silica (sodium silicate, Na₂SiO₃) on digestion of forage with rumen fluid of goat and cellulase, an experiment measuring organic matter disappearance (OMD) of Rhodes grass (Chloris gayana) was conducted using in vitro incubation for 48hr with rumen fluid of goat and with 2.5% Onozuka cellulase SS (P-1500) in an acetate buffer (pH 4.6). In both cultures sodium silicate was added to provide 400, 800 and 1, 200ppm of silica (SiO2) prior to incubation. Rumen fluid was collected from three goats fitted with rumen fistulae and fed a hay. Incubation with cellulase was preceded by that with acid pepsin solution for 48hr. Materials were leaf and stem of an internode elongation (immature) and mature stage of regrowth. The results obtained were as follows: 1. In incubation of leaf and stem of immature and mature materials with rumen fluid containing soluble silica, OMD tended to decrease with increasing soluble silica and at 1, 200ppm level of silica OMD decreased significantly. During the incubations pH of the rumen cultures was close to the upper range of pH of rumen fluid reported. 2. In incubation of materials with cellulase solution, OMD decreased with increasing soluble silica. Although sodium silicate increased pH of the cellulase solution from 0.17 to 0.34 than that with no sodium silicate, increased pH of the solution did not affect OMD. Therefore, soluble silica depressed OMD of the materials by incubation not only with rumen fluid of goat but also with cellulase. This result suggested that cellulolytic enzyme activity was also affected by soluble silica.

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Susceptibility to degradation of protein in the rumen was compared among 20 feeds on the basis of classification of its degradation property⁵⁾. Wheat bran and corn gluten feed were designated as Type A by a high disappearance of nitrogen (N) after the incubation for 2 hours in the rumen by a nylon-bag method. CP 60% fish meal I and milo were classified into Type C by a low disappearance of N after the 24 hour-incubation. The other sixteen B type-feeds were discriminated between Subtype B1 and Subtype B2 by an increase rate of N-disappearance during incubation from 8 to 24 hours. Subtype B1 consisted of safflower meal, linseed meal, meat and bone meal, CP 60% fish meal II, grain screening, feather meal, sesame meal, brewers grain, barley bran and corn. Subtype B2 included soybean meal, rape seed meal, kapok meal, cotton seed meal, brewers grain, coconut meal and palm kernel meal. Susceptibility to degradation of these feed proteins were considered to decrease in the order of either A, B1 and C or A, B2 and C among groups, and in sequence of descrition within each group, grounded principally on the order of N-disappearance at 8 hours after incubation. A clear difference was detected in degradation property between fish meal I and II which were different in respect to manufacturing lot, and brewers grain was assumed to belong to both subtypes. Theoretical grounds of the method (2, 8 and 24 hour-incubation method) employed in this study were discussed in details, and also a joint comparison was made among total 31 feeds used either in the present or the previous work⁶⁾ concerning the susceptibility to degradation of protein in the rumen.

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This experiment was carried out to examine whether energy and protein utilization of chicks were influenced by the dietary carbohydrate source or by the presence of the gut microflora. Diets used here contained glucose or maize starch as a sole source of carbohydrate. Either the glucose or maize starch diet was fed to the germ-free (GF) and conventional (CV) chicks ad libitum from day 4 to day 14 after hatching. Body-weight gain was not affected by the carbohydrate source in both GF and CV chicks, while GF chicks grew significantly faster than CV chicks. Protein retention was significantly higher in the GF chicks than in the CV chicks, although protein retention rate was hardly affected by any treatments. Body fat content was significantly higher on the glucose diet than on the starch diet and was higher in the GF than in the CV chicks. The chicks fed the glucose diet showed higher energy retention than those fed the starch diet. The presence of the gut microflora tended to reduce energy retention of the host bird. The gut microflora enhanced the metabolizability of dietary energy when chicks were fed the glucose diet, but not when the chicks were fed the starch diet. When the chicks were fed the glucose diet, more energy and more protein were required for unit body-weight gain than when the chicks were fed the starch diet. The amount of protein required for unit body-weight gain was increased in CV chicks fed on the starch diet, but not on the glucose diet.

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The influences of dose, age and sex on the growth hormone (GH) secretion in response to a GH-releasing factor, synthetic human pancreatic GH-releasing factor-44 (hpGRF-44), were investigated in goats and sheep. Blood samples were collected before, and for 90min after intravenous (iv) injection of hpGRF-44 from an indwelling catheter previously inserted into one of the external jugular veins, or by venipuncture. The plasma GH concentration was measured by radioimmunoassay. 1) In Saanen female goats, 14 months of age, iv injection of 0.1, 0.25 and 0.5μg of hpGRF-44 per kg of body weight (bw) caused a significant increase in the plasma GH concentration; the peak value was obtained after 5 to 10min. The peak value of GH increased proportionally to the dose of hpGRF-44 injected. 2) The plasma GH concentration in female sheep of 2, 13 and 40 months of age increased significantly after iv injection of hpGRF-44 (0.25μg per kg of bw) and reached a peak 5 to 10min later. In Japanese native meat-type (Shiba) female goats of 5 and 14 months of age, the plasma GH concentration also significantly in creased after 0.25μg of hpGRF-44 per kg of bw injection, and the peak value was obtained after 5min. The peak value of GH decreased with advancing age. 3) In Shiba male and female kids of 1 month and lambs of 2 months of age, iv injection of 0.25μg of hpGRF-44 per kg of bw caused a significant increase in plasma GH concentration and reached a peak after 5 to 10min. The mean peak value of GH in the male animals was higher than that in the female animals. We conclude that the plasma GH response to hpGRF-44 in goats and sheep is dose dependent and decreases with advancing age. The results also suggest that the response in male animals is higher than that in females.

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The purpose of this study is to examine time courses of ¹⁵N in urinary ammonia and total N when ¹⁵N-labeled ammonium acetate was continuously infused for 1 hour into chickens fed a 5 or 20% protein diet. ¹⁵N-enrichment of urinary nitrogen in the two dietary groups increased sharply in ammonia for the first 20 minutes and to a less extent linearly in total N for the first 30 minutes, and then gradually in both ammonia and total N. Through the ammonia infusion, the ¹⁵N-enrichment of urinary ammonia was higher in the chickens fed the low protein diet than in those fed the high protein diet; both of them were higher than ¹⁵N-enrichments of urinary N, which were almost the same in the two dietary groups. The urinary total N from the infused ammonia rose linearly for the first 40 minutes but thereafter did not rise further in the two dietary groups, whereas the endogenous urinary total N tended to decrease a little in the chickens fed the high protein diet but unchanged in those fed the low protein diet. The urinary ammonia from the infused ammonia increased sharply for the first 20 minutes, then linearly but at a lower rate in the chickens fed the high protein diet, whereas that in the chickens fed the low protein diet rose linearly throughout ammonia infusion. In contrast, the endogenous urinary ammonia showed no change in the chickens fed the high protein diet while it showed a tendency to increase a little in these fed the low protein diet. These results indicate that the increased urinary ammonia and total N during ammonia infusion are derived mostly from the infused ammonia in chickens fed 5 and 20% protein diets.

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Degradation of casein by crystalline low-temperature-active proteinase (LT AP) from Streptococcus lactis was investigated. Degradation of various casein fractions (αs-, β-, κ-casein) and whole casein was defined in terms of tyrosine released from casein during reaction. αs-Casein was degraded more easily than other caseins. Degradation of each casein (αs-, β-, κ-casein) in whole casein was also investigated by polyacrylamide gel electrophoresis. The degradation rate of κ-casein was higher than those of other caseins. Crystalline LTAP degraded 37.6% of αs-casein, 41.0% of βcasein and 56.1% of κ-casein in whole casein. The optimum concentrations were 0.2% for whole and κ-casein, 0.1% for β-casein and above 0.5% for αs-casein. The Vmax of crystalline LTAP for αs-casein was larger than β-, κ-and whole casein. The Km values of the enzyme for these caseins were also compared.

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Ejaculated goat spermatozoa were preincubated for 1-5.5hr in the isolated uteri from superovulated hamsters or in Brackett-Oliphant's medium without bovine serum albumin and incubated with zona-free hamster eggs 1-5hr at 37°C under 5% CO₂ in air. Spermatozoa preincubated in the medium for 5.5hr did not penetrate the eggs. However, when spermatozoa were preincubated in the uterus for more than 3hr, the penetration rates greatly increased and the highest rate was obtained following insemination with spermatozoa preincubated for 5.5hr. When the eggs were examined at various times after insemination with spermatozoa preincubated for 5.5hr in the uterus, sperm penetration was first observed 2hr after insemination and the penetration rates increased makedly from 2 to 3hr, but no further increase occurred at 4-5hr. These results demonstrate that goat spermatozoa can acquire the ability to penetrate zona-free hamster eggs during preincubation in the isolated uteri from superovulated hamsters.

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Analysis of the quantitative precipitin reaction of a browning product between β-lactoglobulin and lactose (Lac-β-Lg) or S-carboxymethylated β-lactoglobulin (SC M-β-Lg) with rabbit anti Lac-β-Lg serum indicates that there are at least five or three antigenic sites on Lac-β-Lg or SCM-β-Lg molecule, respectively. These facts suggest that at least three antigenic sites on Lac-β-Lg are formed by a heat denaturation of β-lactoglobulin when Lac-β-Lg is prepared, because SCM-β-Lg hardly react with antiserum to β-lactoglobulin. Hence, in order to study the preliminary localization of the antigenis sites formed by the heat denaturation, peptides 1-7, 8-24, 25-107, 108-145 and 146-162 were isolated from β-lactoglobulin and SCM-β-Lg cleaved with cyanogen bromide, and the antigenic reactivities of the peptides with anti Lac-β-Lg serum were examined. In quantitative precipitin reaction between SCM-β-Lg and anti Lac-β-Lg serum, the mixture of peptides consisting of 1-7, 8-24, 25-107, 108-145 and 146-162 inhibited about 93% of the formation of immune precipitate. Of these five peptides, peptides 25- 107 and 108-145 inhibited about 60% and 24% of the quantitative precipitin reaction, respectively. Peptides 25-107 and 108-145 also inhibited the binding of SCM-β-Lg to the specific Ig G against Lac-β-Lg by enzyme-linked immunosorbent assay. These resuits indicate that four methionyl residues in β-lactoglobulin do not play an important role in the antigenic activity of Lac-β-Lg and that antigenic sites, which are formed as a result of heat denaturation of β-lactoglobulin, are mainly present in 25-107 and 108-145 regions.

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