|Budget Amount *help
¥3,200,000 (Direct Cost : ¥3,200,000)
Fiscal Year 2000 : ¥1,000,000 (Direct Cost : ¥1,000,000)
Fiscal Year 1999 : ¥1,200,000 (Direct Cost : ¥1,200,000)
Fiscal Year 1998 : ¥1,000,000 (Direct Cost : ¥1,000,000)
Holstein bull calves were used to examine factor affecting water balance and fecal moisture content in suckling calves given dry feed for 2 wk from 1 wk of age.
In Experiment 1(n=20) calves, free access to concentrate and timothy hay decreased urine volume and increased apparent water retention, fecal water excretion, and fecal moisture content by 2 wk. In Experiment 2(n=20), free access to concentrate and hay from wk 1 increased reabsorption of water from renal tubules during wk 2. In Experiment 3(n=10), supplementation of 500g/d of milk replacer plus free access to concentrate and hay from wk 1 increased plasma antidiuretic hormone by 2 wk. Plasma antidiuretic hormone concentrations were highly correlated with plasma concentrations of acetate and ketone bodies. In Experiment 4(n=16) calves, apparent water retention and fecal moisture content during wk 2 were increased by free access to concentration from wk 1 but were not affected by rice straw as an inert bulk source. .In Experiment
5(n=16) calves, the shift of water balance (decreased urine volume, and increased water retention and fecal water excretion) and elevation of fecal moisture content were greatest when calf stater and Sudangrass hay were fed in addition to liquid milk. Water retention was correlated positively with digestible DMI and negatively with urine volume. Fecal water excretion was highly correlated with fecal DM excretion. In Experiment 6(n=18), water balance and fecal moisture content during wk 2 were affected by free access to calf starter and hay from wk 1. Urine volume of calves fed dry feed and milk replacer was lower than that of calves fed only milk replacer, however, when water was available in addition to dry feed, urine volume was similar to that of calves fed only milk replacer. Fecal water excretion was highly correlated with water retention rather than with fecal DM excretion. Ruminal fermentation would be an important factor affecting both water balance and fecal moisture content in suckling calves given dry feed. In Experiment 7,8(n=15, However, though the administration in the rumen of the butric acid was made to increase plasma ketone bodies and ADH concentrations, the intravenous infusion of keton bodies did not increase plasma ADH concentrations. Less