The spatial relationship between the Suffolk twin ewes placed outside was investigated for the purpose of obtaining basic data for setting up proper sheep raising circumstances. Twenty-four hour consecutive observation was carried out by a video-recording system at the fenced area (5 m×5 m) in spring and in summer. The distance between the ewes was calculated at each one-minute time interval on a still picture. The difference between the data in respective seasons was investigated. The ewes showed resting behaviour nearly 84% of nighttime in spring, seeming fairly relaxed. Ewes' behaviour in summer showed the tendency of increasing resting rate in hot daytime and increasing activity in nighttime. The mean percentage of the ewe-ewe distance closer than 3 m was 83.8% for daytime and 87.8% for nighttime in spring, and was 59.5% for daytime and 79.6% for nighttime in summer, respectively. At nighttime in the both seasons, the ewes chose the distance between 2 m and 3 m most frequently. From the result obtained from one Suffolk twin pair in such a narrow fenced-in area, more than 3 m space allowance between the twin ewes is desirable.

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In this study we examined the fundamental frequency, formants, and vocal structure at the time of onset in 1 to 3 week-old and 6 to 8 week-old lambs and ewes. We found that fundamental frequency between ewes with open mouths at 1 to 3 weeks was higher than in lambs with closed mouths, while the first formant (F1) in ewes was higher between ewes with a closed mouth than with an open one. We took this as an indication of vocalization based on a low tongue position and suggestive of maternal attention displayed by ewes to their care.
We further found that fundamental frequency was higher in 1 to 3 week-old male lambs compared to females of the same age group, and that vocalization duration was also longer in males than in females, suggesting gender differences being already developed at this stage of lamb development. Fundamental frequency was also higher in both the 1 to 3 week-old and 6 to 8 week-old lamb groups than between ewes, suggesting a number of distinctive features between lamb and ewe vocalization structure.
Our study revealed that the F 1 among 6 to 8 week-old lambs was higher between males than in female lambs, and that the Fl was higher overall between lambs than in ewes. Both of these findings are thought to be as a result of a low tongue position in lambs.
We also found that the second formant (F2) in 6 to 8 week-old lambs was higher between lambs than in ewes, indicating that vocalization in these cases was based on the forward location of the tongue. Through this study we were able to establish that the fundamental frequency between ewes and lambs was higher in 6 to 8 week-old lambs than in 1 to 3 week-old lambs, indicating a diversity in sound and development processes among the subjects. In both male and female lambs the F2 was higher in 6 to 8-week old lambs than in 1 to 3 week-old subjects a result of vocalization for both male and female 6 to 8 week-old lambs being based on the more forward location of the tongue in this group compared to 1 to 3-week old lambs.
The Fl in 6 to 8 week-old lambs was higher in males than in females, thought to be as a result of vocalization in male lambs being based on a lower tongue position than that of females. Our study also found that vocalization duration was longer in 1 to 3 week-old lambs compared to their 6 to 8 week-old counterparts, indicating a demand for attention and care on ewes between lambs.
F1 between males and F2 between females were both higher in 6 to 8-week old lambs than in 1 to 3 week-old lambs, which we took as being dependant on a separation between the high and low and forward and rear positioning of the tongue that accompanies the vocalization developmental stage in both male and female 6 to 8 week-old lambs. We also witnessed differences in developmental structures in 4 different varieties of ewes in particular the breed characteristics of fundamental frequency, formant construction, and duration of vocalization of the Finnish Landrace breed.

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Effect of the supplementary feeding of vegetable rubbish on grazing behavior and body weight gain of lambs in a less favored area (natural grassland) were investigated. Six Suffolk lambs were divided into two groups ; treatment (T) and control (C) groups. Both groups of lambs were kept in one side of the divided grazing area (3.9 a each) enclosed with electric fences. The lambs of group T were fed vegetable rubbish every morning as additional feed. Both groups of lambs maintained their body weight over the grazing periods. In the middle and the latter grazing periods, the proportion of lying-ruminating was significantly high in group C than T (both P<0.05). Group T showed higher proportion of moving than group C. The lambs of group T began to eat the vegetable rubbish from the second grazing week. These results suggest that it was useful to feed sheep on vegetable rubbish in natural grassland. Feeding sheep on vegetable rubbish can prevent unwitting feeding to wild animals by vegetable dregs left in the fields.

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