Investigations were carried out on the effects of water and food deprivation on the milk yield, body weight, blood composition and urine volume of lactating Nubian goats. The animals survived 4 days of deprivation of either food or both food and water, but these treatments resulted in about 10 per cent loss in body weight, 85 per cent drop in urine volume, and cessation of milk production, but no significant changes in packed cell volume, serum sodium, potassium and total protein. The change in body weight could be reversed within 1 day, but the initial milk yield was not resumed during the 2 weeks immediately following restoration of food and water.

The objective of the study reported here was to investigate three factors that may affect the amounts of water consumed and urine excreted by a rat in the metabolism cage: water dilution, housing, and food. Young F344/N rats (eight per group) were used for all experiments. Food was withheld from rats before each 16-h urine collection, then rats were transferred into a metabolism cage. For trial A (water dilution), urine was collected from rats supplied with dyed water (0.05%,vol/vol). This was repeated three times over a 2-week period. Dye in water or urine was quantified, using a spectrophotometer. For trial B (housing), rats were individually housed in wire cages for 3 weeks before the first urine collection. Then they were group housed in the solid-bottom cage (four per cage). After 2 weeks of acclimation, urine collection was repeated. For trial C (food), one group of rats was provided with food, the other was not, during urine collection. About 8% of urine samples of small volume (less than or equal to 3 ml) from trial A were contaminated with drinking water up to 13% of volume. The average urine volume associated with individual housing was approximately twice as large as that associated with group housing. When food was provided during urine collection, rats consumed similar amounts of water but excreted significantly smaller amounts of urine than did rats without food. It was concluded that water dilution of a urine sample from a sipper bottle is relatively small; rats individually housed in wire caging before urine collection can consumed and excrete a larger quantity of water, compared with rats group housed in solid-bottom cages: and highly variable urine volumes are, in part, associated with lack of access to food during urine collection.

PURPOSE Body composition is strongly associated with cardiometabolic risk factors, and accurate measurement of body composition is vital for the management of chronic diseases. In this study, we assessed whether major factors such as urination, aerobic exercise, food, and water consumption had significant effects on body composition by segmental bioelectrical impedance analysis (BIA). METHODS To achieve the goal of this study, research was conducted on 32 healthy young males (n=18) and females (n=14). All participants underwent body composition analysis in four different conditions (both pre- and post-urination, moderate-intensity aerobic exercise for 30 minutes, immediately after food and water consumption, 30, 60, and 120 minutes after each treatment), and segmental BIA was performed using Inbody720. RESULTS We found that after urination, body weight, skeletal muscle mass, and basal metabolic rate (BMR) significantly decreased. However, water intake significantly increased body weight, body fat mass, and body fat percentage. Furthermore, an acute 30-minutes aerobic exercise significantly decreased body weight, fat mass, and fat percentage, and increased skeletal muscle mass and BMR. In addition, impedance decreased immediately and increased 120 minutes after the acute aerobic exercise. Finally, food ingestion significantly increased the body weight, skeletal muscle mass, and BMR. CONCLUSIONS Our study suggests that variables such as urination, exercise, food consumption, and water intake should be considered to accurately assess body composition.