The present study was investigated the fertility of 74 ewes after embryo transfer of fresh, frozen-thawed and vitrified ovine embryos collected on 6-7 days after artificial insemination with fresh-diluted or frozen-thawed ram semen by the simple superovulation treatment during the period of 1998 to 2009. There was no significant differences among the pregnant and lambing rates after transfer of fresh (40.9 and 36.4%), frozen-thawed (26.3 and 26.3%) and vitrified (27.3 and 27.3%) embryos. However, the twining rate (33.3%) using vitrified embryos was significantly (P<0.025) lower than that (87.5%) of fresh embryos. From a total of 74 ewes transferred embryos, 22 ewes lambed (30.9%) with 61.9% (13/22 heads) of twining rate. Although the present fertility were still low (27-36%), the results indicated that lamb production was possible by transfer of frozen-thawed and vitrified ovine embryos using laparoscope.

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The effect of oscillating the metabolizable protein (MP) provision on the nitrogen (N) utilization in adult sheep was studied. Four crossbred Suffolk adult rams were fed the diets with following feeding regimens by a change-over experimental design ; static feeding a diet at maintenance level of requirement (control treatment), and oscillating feeding with two diets which can provide low (60%) and high (140%) quantities of MP at maintenance level of requirement on a 48 h basis (oscillating treatment). These diets were formulated to give comparative provision levels of both metabolizable energy (ME) and MP at 4 days of unit by using the in situ rumen degradation parameters of organic matter and N, and chemical composition of feed ingredients. The animals were fed control and oscillating diets for a period of 23 days, respectively, and metabolism trial, rumination behavior recordings and blood sample collections were carried out for the last 9 days of the period. Animals consumed their diets thoroughly. The estimated intakes of ME and MP did not differ significantly between the treatments (P>0.05). The apparent digestibility were not affected by feeding treatments (P>0.05). Urinary N excretion was significantly lower for oscillating treatment than for control treatment (P<0.01). Although the figures of N retention did not differ significantly between the treatments (P>0.05), it seemed to be numerically higher for oscillating treatment as compared for control treatment. The concentrations of plasma urea N and glucose were significantly higher for oscillating treatment than those for control treatment (P<0.001). There was no difference in microbial N supply between the treatments (P>0.05), while the efficiency of microbial synthesis was higher for oscillating treatment compared with control treatment (P=0.001). The results obtained in this study suggest that oscillating MP provision by feeding two rations with high forage ratio could increase the utilization of N by reducing their urinary N excretion or increasing urea recycling in adult ram at their maintenance level of feeding.

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In the present study, the degradability of dry matter (DM) and crude protein (CP) in 6 grass and 4 legume forages was measured using nylon bag technique to investigate the degradation characteristics of roughages in the rumen of sheep. A castrated male sheep (BW, 41kg) fitted with rumen cannula (4cm I.D.), and fed a mixed hay ration (2.0%DM/BW) was used for incubation of the samples. Each forage samples (3～5gDM) tested were put into the nylon bags (20～20mesh) after air dried and ground, and the incubation times in the rumen were 8, 12, 48 and 72 hours, and for each incubation time the 3 bags were prepared with one sample. In each incubation time, DM degradability of legume forages was higher than that in grass forages until 48 hours, and the degradability of CP in legume forages was also higher than that in grass forages. In legume forages, the extent of increase in both degradability of DM and CP tended to small after 24 hour incubation. The degradability of CP in grass forages after incubated during 12～24 hours, and that in legume forages after incubated during 8～12 hours was very close to the digestibility of CP after digestion trials using sheep.

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The aim of this study was to elucidate the difference between male and female sheep in their behavioral response to daily caretakers and how the age of animals influences the response. Ten Corriedale males (2 to 13 years old) in 3 groups and 10 Corriedale females (0 to 13 years old) in 2 groups kept all year round in 5 outdoor paddocks of ca. 10×10 square meters, respectively, were used. Experiments were performed by 2 daily caretakers (male and female adults). Three kinds of measurements were made : 1) approach distance to a person standing outside or inside the paddock before, at, and after feeding ; 2) flight distance to a person approaching the animals in the paddock at a speed of 0.5m/sec before, at, and after feeding ; 3) capture time by one or 2 persons in an 8×8 square meters fenced area. Since no approaching behaviors occurred in animals at feeding, animals' interest for caretakers seemed to be lowered at feeding. Before feeding, approach distances (medians of 10 animals) to a person standing outside the paddock were 0.4m in males and 1.3m in females, respectively. When the person entered the paddock, female sheep retreated to some extent from the person. The approach distances measured inside the paddock were 0.0m in males and 3.8m in females, respectively. After feeding, approach distances measured outside and inside the paddock were inclined to be shorter in males (4.0m and 3.3m) than in females (6.0m and 6.0m). In both males and females, approach distances before feeding were significantly (P<0.05) shorter than those observed after feeding. The short approach distances before feeding may reflect the animals' expectation of feeding by the caretakers. From the longer approach distance of females, it is presumed that they have stronger wariness of people than males. Retreat of females observed when caretakers entered the paddock also suggests the stronger wariness of people in females. A fence separating animals from people may have a lowering effect on animals' wariness of people. Flight distances observed before, at, and after feeding were 0.0m, 0.0m, and 0.0m in males, and 1.3m, 0.0m, and 0.5m in females, respectively. In females, values before and after feeding were significantly (P<0.05) larger than that at feeding. Before feeding, females showed a significantly (P<0.05) longer flight distance than males. Males seem to have almost no wariness of caretakers in contrast to females, which seem to be not so wary of caretakers only at feeding. Since the capture time of females (52.8sec) was significantly (P<0.01) longer than that of males (6.4sec), it was supported further that females are warier of people than males. Since all the maximum values in approach distance, flight distance, and capture time were observed in the animals of 3 to 4 years old, it was presumed that sheep's wariness of people becomes highest at around 3 to 4 years old.

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