To study the effect of tap water with magnetic treatment on drinking water intake (DWI), dry-matter intake (DMI), digestibility of dry matter and nitrogen balance of sheep, 8 ewes were individually kept for 288 days in a metabolism crate including a 120-day preliminary period. A half of them were given water with magnetic treatment for 168 days of which the period was divided into 6 treatment periods of 28 days. Daily record was taken for barn temperature together with DWI and DMI of individual animal in the period of 288 days. Metabolism trials were carried out in the last 7 days of each treatment period. The determination was made on the concentration of blood urea nitrogen (BUN) on the day before the last day of each period and live weight on the last day. The magnetic treatment of tap water was done by the use of an apparatus of magnetic field (PANOX G30). The quantity of water drunk, dry-matter ingested or nitrogen retention was expressed on the basis of metabolic body size/day (kg^0.75·day). Statistical analyses were carried out by the t-test comparing mean values of parameters for control and treatment groups at each treatment period. The level of significance was tested at p< 0.05.
At preliminary period, mean values with standard deviation for live weight, DMI and digestibility of dry matter were as follows for animals in control group, 71±7kg, 51±7g/kg^0.75·day and 67.1±3.7%, and in treatment group, 71±16kg, 51±6g/kg^0.75·day and 66.5±1.2%, respectively. There were no significant differences between two groups for DWI, DMI, digestibility of dry matter or nitrogen, nitrogen retention and BUN. There was, however, a tendency to be different pattern in the changes with barn temperature in DWI and DMI between both groups, which suggests that a possibility of water with magnetic treatment cause a difference in a response of animals. The further study is needed to clarify animal response to water with magnetic treatment.

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This study was conducted to investigate the relative dominance of visual, auditory and olfactory cues in lambs' distinction of their own mother from alien ewes. Subjects were eight Suffolk lambs and were given a series of 20 choice trials between their own and alien mothers in a Y-maze. In the choice trials, four kinds of sensory cues (compound and one of visual, auditory and olfactory cues) were provided for lambs. As results of χ²-test, only five subjects exposed to the compound cues could significantly choose their own mother. The Wilcoxon rank-sum test showed that lambs exposed to the compound (P < 0.05) and the visual cues (P < 0.10) tended to choose their own mothers than alien ewes. The analysis of the first ten and the later ten trials indicated significant choices of their own mothers (χ²-test, P < 0.05) by three, one, one and one lambs exposed to the compound, visual, auditory and olfactory cues, respectively. In addition, two lambs tended to choose their own mothers when exposed to the compound, visual and auditory cues (P < 0.1). It is concluded that lambs usually distinguish their own mothers by means of the compound cue, but they can distinguish their own mother in case that only one kind of sensory cue is available. The relative dominance in the sensory modalities involved in lambs' distinction of their own mothers could be visual > auditory ≥ olfactory cues in order.

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When early weaning, two experiments were conducted to study the effect of omission of milking during drying-off period (14 days after weaning) and continuous feeding concentrate for 7 days before weaning on the body weight change and milk quantity of ewe during drying-off period.
In the first experiment, a total of 14 Suffolk ewes suckling lambs were divided into 2 groups (control group and none-milking group), and ewes were housed indoors. In both groups, ewes were weaned at 70 days after lambing. In control group, ewes were hand-milked once a day at 4, 8 and 14 days after weaning. In none-milking group, ewes were not milked. In both groups, ewes were fed hay and concentrates from lambing until 63 days after lambing, thereafter, they were fed hay only.
In both groups, ewes showed a decrease in their body weight during 7 days before weaning. During drying-off period, ewes in control group showed a decrease in their body weight, although ewes in none-milking group showed little change in their body weight. The mean milk quantity in control group at 4 days after weaning was 0.16 kg, then showed a rapid decrease at 8 and 14 days after weaning. In none-milking group, the examination revealed that the udder on ewe shrank gradually without distention or heat during drying-off period. These data showed that, when ewes are discontinued feeding concentrates for 7 days before weaning, drying-off can be carried out without milking.
In the second experiment, a total of 30 Suffolk ewes suckling lambs were divided into 2 groups (control group and continued group), and ewes were housed indoors. In botn groups, ewes were weaned at 70 days after lambing, and hand-milked as in control group in experiment 1. In control group, ewes were fed hay and concentrates from lambing until 63 days after lambing, thereafter, they were fed hay only. In continued group, ewes were given hay and concentrates from lambing until 70 days after lambing, thereafter, they were fed hay only.
For 7 dyas before weaning, Ewes in control group showed a decrease in their body weight, although ewes in continued group showed a increase in their body weight. During drying-off period, ewes in both groups showed a decrease in their body weight. Although the mean milk quantity for continued group at 4 days after weaning was higher than that for control group (0.32 vs 0.21 kg, P < 0.01). Then those of both groups showed a similar decrease at 8 and 14 days after weaning. These data showed that, when ewes were continued feeding concentrates until weaning, drying-off can be carried out with milking and ewes can gain before weaning.
Both means may have practical value in Japanese sheep raising.

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The physiological actions of brain neuroactive peptides in the central regulation of blood constituents in sheep were investigated through continuous intracerebroventricular (ICV) infusions. Sheep were given ICV infusions of Corticotropin-releasing factor (CRF), Urocortin (UCN), Neuropeptide Y (NPY), Angiotensin II (ANG II), Somatostatin 1-28 (SRIF), Artificial cerebrospinal fluid (CSF) at small doses of 5 μg/0.2 ml/h for 98.5 hours over a 5 day period. These neuroactive peptides may be involved in brain mechanisms controlling feed intake in ruminants. Sheep (n=5) were fed alfalfa chaff for 2 hours (12 : 00-14 : 00) once a day, and water and 0.5 M NaCl solution were given ad libitum using a pedal press system. Before feeding, the heart rate and mean arterial blood pressure (MAP) were measured, and a blood sample (10ml) was taken. The measurements of these parameters and blood sampling were conducted prior to, during and post ICV infusion of CSF or neuroactivepeptides. The measurements of these parameters were taken prior to feeding. All parameters measured in this experiment were not influenced by the continuous 98.5 hr CSF infusion. The mean arterial blood pressure (MAP) during ICV infusion of ANG II increased significantly compared to that during CSF infusion. The plasma glucose concentration during ICV infusion of CRF, UCN and NPY increased compared to that during CSF infusion, respectively. The plasma total protein concentration during ICV infusion of CRF and UCN increased significantly compared to that during CSF infusion, respectively. The plasma concentrations of Na, Cl, total protein and osmolality during ICV infusion of ANG II tended to be lower than that prior to infusion. The levels of changes in these parameters were within the ranges of physiological response. The results suggest that these neuroactive peptides play a physiological role in the central regulation of blood constituents.

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Difference in the sucking behaviour of Suffolk lambs in the nursing period was observed for the purpose of obtaining useful basic data for proper sheep management, using two ewe single-born lamb pairs and four ewe twin lambs sets.
Ewes and their lambs were kept in pens of 4-5 m² each. Ewes were fed at 8 : 30 and 17 : 30. Continuous twenty-four hour observations were performed by video-recording system using an infrared camera on the 1st, 2nd, 3rd, 5th, 7th, 14th, 21st, 30th, 60th and 90th day after their birth.
Both of the single lambs and twin lambs showed 17-18 hours of resting behaviour in squatting or lying posture until 1 week of age, showing no difference in the amount of resting time between daytime (6 : 00-18 : 00) and nighttime (18 : 00-6 : 00). After 1 week of age, the total amount of time of resting behaviour of single group and twin group decreased gradually with the weeks of age in daytime, however remained about the same level during nighttime. The total amount of time of single lambs' resting behaviour showed a tendency to be longer than that of twin lambs.
The sucking behaviour of lambs of both birth types increased until 1 week of age, and the values of frequency per day were 71.3 times for single lambs and 80.0 times for twin lambs at 1 week of age. In the case of single lambs, the highest number of mean frequency per day was 121.8 times at 2 weeks of age. After 2 weeks of age, the mean frequency of sucking behaviour of single lambs showed a tendency to be higher than the means of twin lambs. The total amount of time of sucking behaviour per day was 28.4 minutes for single lambs and 57.0 minutes for twin lambs at 1 week of age. After 3 weeks of age, the total amount of time of sucking behaviour per day decreased gradually and was 3.0 minutes for single lambs and 4.3 minutes for twin lambs at 3 months of age. The means of sucking bout duration of single lambs were shorter than the means of twin lambs, and both means were 14.4 seconds for single lambs and 22.1 seconds for twin lambs at 3 weeks of age.
The tapping frequency per single sucking behaviour of both birth types increased until 3 weeks of age, and the means after 3 weeks of age were 1.4-1.6 times for single lambs and 0.9-1.1 times for twin lambs.
These results showed that the difference in the sucking behaviour existed between single group and twin group. In the case of twin lambs, it was predicted that their mothers' milk would not be sufficient to cover their nutrient requirements. Especially in the case of newborn twin lambs, it should be important to take as much care as possible.

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