Leucaena leucocephala has been utilized with limit as livestock feeds due to the existence of a toxic mimosine. So, it is necessary to induce mimosine toxicity to the experimental animals to study its cure and elucidation. The studies on inducing mimosine toxicity by feeding L. leucocephala seed powder to chicks were carried out. Chicks were fed normal diets with 0, 10, 15 and 20% of L. leucocephala seed powder, and 1% crude mimosine for 12 days. Chicks fed toxic diets had decreased food intake and body weight gain, leg weakling symptom and enlargement of kidney. Mimosine was detected in the tissues of chicks fed the poisonous diets. Chicks orally administered crude mimosine were found to have alleviated the decrease of food intake and body weight gain. Chicks fed 15% seed powder diet for 12 days at 1-5 weeks of age, respectively, had decreased food intake and body weight gain regardless of growing stages, but mimosine content in the tissues decreased with growing age. After feeding 15% seed powrdiet for 12 days, chicks were fed a normal diet for 20 days. Food intake of the chicks increased from the 1st day when the diet was changed to normal diet. Mimosine considerably existed in the feather and thyroid gland on the 20th day, but disappeared in the kidney, serum, liver and excretion. So, male broiler chicks were found to be rapidly and easily induced to mimosine toxicity by feeding 15% L. leucocephala seed powder diet for 12 days, and stored mimosines in the tissues rapidly reduced by feeding a normal diet.

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The effects of microwave radiation and cellulase addition on the fermentation quality, chemical composition and in vitro dry matter digestibility (IVDMD) of fresh rice (Oryza sativa L.) straw silage were studied. Fresh rice straw (DM 38.7%) was irradiated with microwaves for 0, 3 or 6 min on a frequency of 2450 MHz with 600 watts of power and ensiled after adding lactic acid bacteria with and without Acremonium cellulase. Microwave irradiation significantly (P<0.01) limited the hydrolysis of sucrose in the material prior to ensiling and increased the contents of neutral detergent fiber (NDF) and hemicellulose of silages. It obviously improved the fermen-tation quality of silages as indicated by higher contents of lactic acid and residual water-solublecarbohydrates (WSC), and lower pH values and contents of butyric acid and volatile basicnitrogen (VBN). Acremonium cellulase had relatively greater effects on the pH values, lactic acid, crude fiber and NDF contents in the irradiated silages than those in unirradiated silage. However, all treatments did not affect IVDMD.

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Excretion of cattle, pigs and chickens were kept at 24°C under high humidity, and changes in microbial flora were observed for 7 days. In the excretion of cattle, the levels of aerobic-cultured bacteria, anaerobic-cultured bacteria, enterobacteriaceae and staphylococci increased 1 day after excretion, and stable until day 7. The dominant aerobic-cultured bacteria was streptococci in fresh feces and was replaced by enterobacteriaceae on and after day 1. Bacteroidaceae was the most abundant anaerobe ; however, the level was lower than that of enterobacteriaceae. In the excretion of the pigs, the levels of aerobic-cultured bacteria and streptococci was constant until day 7. The dominant aerobic-cultured bacteria was streptococci in fresh feces and was replaced by enterobacteriaceae on and after day 3. The levels of anaerobes increased until day 3. In the fresh feces, levels of eubacteria and lactobacilli were almost the same as that of enterobacteriaceae ; however, enterobacteriaceae was the most abundant on and after day 1. The data from the cattle and pig indicated that enterobacteriaceae became the dominant microbe after excretion, and that the levels of the other microbe, even though anaer-obes, were not drastically changed until day 7. Chicken feces showed different tendency that anaerobes was more abundant than aerobes and the levels of either anaerobes examined were larger than that of enterobacteriaceae.

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Using the in situ technique, the effective degradability of crude protein (CP) of soybean meal was determined in the rumen of sheep given four kinds of hay: alfalfa (AL), bermuda grass, Italian ryegrass (IR) and sudan grass (SG) in order to assess the degradability (dg) values of CP in soybean meal (SBM) determined under different hay feeding regimens. The intake of hay tended to be higher in AL and bermuda grass (BG) feeding than in IR and SG. The rate constants of rumen passage did not differ significantly among the different hay feeding with a tendency to have a higher rate in AL feeding. The degradation rate of CP in SBM tended to be higher in AL and BG feeding than in IR and SG. The effective degradability of CP in SBM determined under feeding of BG was significantly higher than the feeding of other hays. When the range of tabulated dg values of CP was considered, the difference found in the present study was inferred to cause no critical errors in the calculation of the de values of CP in SBM.

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Phylogenetic relationship of three wild species and two livestock species of Caprini was estimated based on nucleotide sequences for cytochrome b gene in mitochondrial DNA. DNA samples were prepared from blood and liver of Pasang (Capra aegagrus), Markhor (Capra falconeri), Mouflon (Ovis musimon), domestic goat (Capra hircus) and domestic sheep (Ovis aries), respectively, and used for amplifying whole cytochrome b gene DNA by the polymerase chain reaction. The base sequences were directly determined by the dideoxy terminator cycle sequence method using the amplified DNA. In the cytochrome b gene (1140bp), maximal homologies, 99.4% and 99.3%, were obtained between Pasang and domestic goat, and between Mouflon and domestic sheep, respectively: The next closest combinations were between Markhor and domestic goat (96.6%) and between Pasang and Markhor (96.0%). Any of the other combinations gave lower homo-logies. The phylogenetic tree constructed by the neighbor-joining method from the present and previous results confirmed that Pasang and Mouflon was closest to domestic goat and domestic sheep, respectively, though Markhor had also closer relationship to domestic goat and Pasang than to Mouflon and domestic sheep. These results strongly support the previous hypothesis from morphological studies that domestic goat and domestic sheep have been established from Pasang and Mouflon, respectively, and Markhor has contributed partially to the establishment of domestic goat.

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In previous experiment, we found that exposure of goats to heat caused an increase in ruminal volatile fatty acids (VFA) absorption. In order to investigate the relationship of this increase with changes in the ruminal production of VFA, the rumen fluid concentrations of VFA and the digestibility of feed fractions were determined in goats which were exposed to thermo-neutral (23°C, 80% relative humidity) and hot (32°C, 80% relative humidity) environrnents. In the thermoneutral environment and on the 4th (H4) and 20th (H20) days after exposure to the hot environment, rumen fluid samples were collected at fixed intervals for 24 hours. On these days, digestibilities of feed fractions were determined. Equal amounts of feed, composed of 67% alfalfa hay cubes and 33% beef cattle commercial formula feed was fed twice daily in both treatments. These rations were consumed within 1 hour. Animals were allowed to drink water freely during 1 hour feeding periods. The water intakes on H4 and H20 were slightly greater than that in the thermoneutral environment. The concentrations of acetic, propionic and n-butyric acids in rumen fluid on H4 and H20 were lower than those in the thermoneutral environment. The ruminal concentrations of iso-butyric acid and iso-valeric acids on H4 were the same as those in the thermoneutral environment, with values on H20 tending to be lower. On the other hand, digestibilities of dry matter, organic matter, crude protein, nitrogen-free extracts and NDF on H4 were higher compared to those in the thermoneutral environment. However, no differences in these criteria were found between H20 and thermoneutral environment. The digestibilities of crude fat, crude fiber and ADF on H4 and H20 were greater than those in the thermoneutral environment. From these results and previous work, it is suggested that although VFA concen-trations were lower due to their increased absorption and higher water intake, heat exposure brought about an increment in digestibilities of feed fractions and eventually resulted in higher ruminal VFA production.

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Relationship between nitrogen excretion and feeding performance was investigated to predict the amount of nitrogen excretion. To obtain the prediction equations of the amount of nitrogen excretion, results of 95 nitrogen balance trials with lactating cows under environment controlled roams (18 and 20°C) were used. The equation obtained was as follows: N/FCM=-14.48×ln(FCM)+0.806×CP+0.769×DMI+31.4R²=0.864(N/FCM: nitrogen excretion (feces plus urine) per 1kg fat corrected milk, g, FCM: fat corected milk, kg, CP: crude protein content in dry matter, %, DMI: dry matter intake, kg). Partial corelation coefficients were -.906, .842 and .769 for lnFCM, CP and DMI, respectively. Therefore increasing milk yield, depression of CP content and improvement of feed quality are useful to reduce nitrogen excretion.

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Eleven wethers (average weight 60.5kg) were used in the experiments to evaluate rare earth labeled hay and its neutral detergent fiber (NDF) as particulate phase marker for estimation of passage rates. Wethers were fed one of the four hays: orchardgrass (Dactylis glomerata L.), timothy (Phleum pratense L.), first and second growth alfalfa (Medicago sativa L.) hays, about 40g/w0.75 once a day. The trial consisted of a 7-day adaptation period and a 14-day sampling period. On the morning of the 7th day sampling period, wether were orally given dysprosium (Dy)labeled hay and ytterbium (Yb)-labeled NDF as particulate phase marker and Co-EDTA solution as liquid phase marker. Ruminal passage rates (k₁), post-ruminal passage rates (k2), transit time(TT: time of first appearance of marker in feces) were calculated from fecal excretion curves of markers. Compared with grass hays, alfalfa hays contained similar NDF and cellulose and more acid detergent fiber and acid detergent lignin. k₁ of Dy-hay and Yb-NDF for timothy, orchargrass, first growth alfalfa and second growth alfalfa were 1.9; 1.7, 1.7; 1.6, 2.9; 1.7 and 2.3; 1.7%/hour, respectively. The rate constant k₁ estimated from Yb-NDF were significantly slower (p<0.01) than the rate from Dy-hay. There was no difference in k2 and TT between rare earth labeling sources. There were high positive correlations (r=0.853^**) between k₁ estimated from Dyhay and ruminal passage rates of liquid phase calculated from fecal Co excretion curves. These results suggested that estimation of ruminal passage rates vary with the kind of rare earth labeling source.

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The purpose of this paper was to discuss the effect of feed intake levels on heat production (HP) and mean body temperature (Tb). Heart rate (HR), heat production (HP), rectal temperature (Tr), vaginal temperature (Tv) and skin temperatures (Ts) of four Holstein heifers were measured continuously. The experiment consisted of three feed intake levels; Low (L, DG 0.0kg), Medium (M, DG 0.6kg) and High(H, DG 1.2kg). The levels of HR and HP were affected by the feed intake levels, and there were significant differences (p<0.05) between each feed level. The response of Tb was also affected by the feed intake levels, and was significantly different in the low and high feed intake levels. The regression equations of HR (X) on HP (Y) were significant with all four heifers. The regression equations of HP (X) on Tb (Y) were significant with all four heifers. The mean correlation coefficient was 0.04. The influence of feed intake and HP on thermoregulation could be estimated by measuring Tb.

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We examined the similarity within identical twins of superovulatory responses, using three pairs of identical twins (pair A, B and C) of Japanese-Black heifers produced by transferring an embryo divided into two. After birth, three pairs of identical twins were kept under the same conditions, feeding, management and environment. Three pairs of identical twins were super-ovulated by conventional methods two times and we examined the numbers of corpora lutea (CL), collected ova (CO), transferable embryos (TE) and rate of transferable embryos (RTE, %). On the first flushing, the CL of pairs A, B and C were 15 .15, 10.12, 20 over . 18; the CO were 10.11, 20.15, 23.30 and the TE were 3.8, 16.13, 18.19, respectively. The RTE of pairs A, B and C were 30.0% 66.7%, 80.0% .86.7% and 78.3% .63.3%, respectively. On the second flushing, the CL of pairs A, B were 13.13, 9.8 ; the CO were 10.15, 12.9 and the TE were 7.9, 10.7 respectively. And in pair C, the CL were both 16, but the CO were 18.9 and the TE were 13.6 on account of failed flushing of one uterine horn. The RTE in three pairs have similarity within each twins. From these results, we guessed that the similarity of superovulatory responses within identical twins kept under the same feeding, management and environment is high.

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Results of 134 feeding trials by lactating cows under high temperature conditions (more than 20°C of minimum temperature) were used to predict dry matter intake (DMI) in summer. The equation obtained was as follows: DMI= 0.0128BW+0.343FCM+0.083R/C-0.372CP+0.229 TAVE+0.088 HAVE-7.00 R²=0.683 RSD=1.56 (BW: body weight, kg, FCM: fat corrected milk yield, kg, R/C: roughage ratio, %, CP: crude protein, %DM, TAVE: average temperature, °C, HAVE: average relative humidity, %). This equation was suggested that DMI in summer was controlled by heat production described by BW, FCM, R/C and CP, and environments which affected heat losses.

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