Different oral rehydration therapies are used to restore the electrolyte level in diarrheic dairy calves. Most of them demand great amount of labor and time, however the use of commercial supplements administered with the liquid diet may make it easier. The objective of this study was to evaluate 3 rehydration protocols to determine the most effective in restoring electrolytes and water while maintaining animal performance. Thirty male Holstein bull calves were blocked by birth weight and serum total protein 24 h after birth, and distributed to one of 3 protocols of oral rehydration when presenting fecal score higher than 3 in a scale of 1 to 5: (1) Common electrolytes oral solution: 25 g dextrose, 10 g of sodium bicarbonate and diluted 5 g of sodium chloride in 1 L of water supplied at 10:00 and at 14:00); (2) commercial electrolyte solution vial for calves added to the milk replacer; and (3) Common electrolytes oral solution containing 2.2 g of glutamine and glutamate diluted in 1 L of water supplied at 10:00 and 1L at 14:00 h. All animals received 4 L/d milk replacer divided into 2 meals (7 h and 17 h) and were weaned with 56 d. Starter concentrate and water intake were measured daily and calves were weighed weekly. Although there were no significant differences among treatments for consumption, weight gain and days in diarrhea, voluntary water intake was significantly higher for diarrheic calves that received Glutellac, which together with the simplicity of use, represent the major advantages of this method of rehydration. Table 1. Performance of dairy calves receiving different rehydration treatments when presenting diarrhea

Item	Dextrose solution	Commercial electrolytes	Dextrose + AA solution	SEM	P <
Total DMI, g/d	713	747	670	41.3	0.41
Starter intake, g DM/d	267	199	225	37.0	0.35
Milk replacer intake, g DM/d	447	448	445	2.2	0.6
Total water intake, L/d	3.50	2.96	3.31	0.20	0.201
Voluntary water intake, L/d	1.50b	2.96a	1.30b	0.20	0.0001
Average weight, kg	40.7	40.6	39.1	2.5	0.63
ADG, g	309	340	292	32.4	0.53
Feed efficiency	0.36	0.34	0.37	0.03	0.35