Water and concentrate intake, weight gain and duration of diarrhea in young suckling calves on different diets

Diarrheic calves are fed with milk or milk replacer and oral rehydration solutions (ORS) to ensure energy and electrolyte supply. An easy and time-saving method is the preparation of ORS in milk. As milk-based ORS are hypertonic solutions administration of them may trigger thirst. Therefore, we hypothesized that restrictively fed calves receiving ORS prepared in milk had a higher water intake than restrictively and ad libitum fed calves receiving ORS prepared in water during diarrheic episodes. The daily water intake was measured in 100 individually-housed Holstein Friesian calves from day 2 to 21 of life. One group of the calves was fed with restrictive amounts of milk, the other group got milk ad libitum by an automated milk feeder. Nearly all calves spontaneously developed diarrhea within the observation period from day 2 to 21 of life. In cases of diarrhea the restrictively-fed calves received ORS prepared in milk or ORS prepared in water two hours after their milk meal, whereas the ad libitum-fed calves only got ORS prepared in water. All calves had ad libitum access to water. The daily intake of water, milk, and ORS and weight gain during diarrheic episode were determined. Data were expressed as arithmetic means (±standard deviation) and analyzed by using a one-way ANOVA or repeated-measures ANOVA. From day 2 to 21 of life calves fed with restrictive amounts of milk had higher water intakes related to the total dry matter intake (DMI) with 1.6 L/kg of total DMI than ad libitum-fed calves (0.9 L/kg of total DMI) per day. In cases of diarrhea water intake increased in all feeding groups. The calves receiving milk-based ORS had the highest water intake with 1.7 L/d during the period of diarrhea compared to the calves received ORS prepared in water. Moreover, the calves fed ORS in milk showed with 4.6 L/d the highest daily ORS intake. There were no differences in the duration of diarrhea or the daily weight gain during period of diarrhea between the feeding regimens. Therefore, it can be concluded that all feeding regimens were suitable in the treatment of calf diarrhea. The simplest method to treat calves suffering from diarrhea is the preparation of ORS in milk, but then ad libitum availability of water is absolutely necessary. Moreover, calves drink considerable amounts of water within the first 3 weeks of life and therefore should be provided with water for animal welfare reasons.