Water is the most important nutrient for calves and plays an important role as solvent of nutrients, rumen development, thermoregulation and other functions in the body. In addition other researchers found that calves started feed consumption earlier and consumed more when unlimited access to clean drinking water is available. Generally, water comprises 70 to 75% of the weight of the calf, and they require greater amount of water per pound of body weight compared to mature animals. Water from milk or mixed with milk replacer provides fluid to calves during the pre-weaning period, although this water directly passes to the abomasum through the esophageal groove. Thus clean, soft, and fresh water should be provided separately throughout their early life. Newborn calves are more sensitive to greater concentration of total dissolved solids (TDS) in water compared to older calves. Calves are also highly vulnerable to greater concentrations of iron, sulfate, manganese and magnesium and microbial contamination. These factors may cause digestive disorders like diarrhea. Loss of water through feces may causes dehydration and electrolyte imbalance. It was therefore hypothesized that improving water quality by a reverse osmosis system will improve growth performance and wellbeing of calves.
A research project was conducted at the SDSU Dairy Research and Training Facility with twenty-four Holstein calves to determine the effects of drinking reverse osmosis water (ROW) versus municipal city water (MCW) on growth and health performance of calves. Briefly, calves were housed in individual hutches during the 10-week study. Treatments were ROW (Culligan Water filtration system, Brookings, SD) versus MCW (Brookings Municipal Utility, Brookings, SD) which contained 13 and 387 ppm TDS, respectively. Iron concentration of ROW and MCW were 0.04 and 0.17 ppm, respectively. Sulfate concentration was 195 ppm in MCW compared to 1.35 ppm in the ROW. Milk replacer (28% CP; 18% Fat) was fed twice daily during the first five weeks and then once daily during week six. At each feeding 1 lbs of dry milk replacer was mixed with 3 quarts of the respective water type according to treatment. Calves were fed water and starter pellets free choice throughout the study. All intakes were recorded daily. Health parameters were observed daily after the morning feeding by one individual (rectal temperature, cough, ocular and nasal discharge, alertness, and fecal consistency). Daily total respiratory scores were calculated from the sum of scores for rectal temperature, cough, ocular, and nasal discharge (Method developed by the School of Veterinary Medicine, University of Wisconsin). Body weights (BW) and frame growth were measured two days every two weeks, and jugular blood samples were collected after three hours after morning feeding. Total tract digestibility was analyzed by compositing fecal samples three consecutive days during week 10.
Total DMI and gain to feed ratio increased more over time for ROW than MCW (Table 1). Surprisingly, water intake was slightly less in ROW than MCW, but this may indicate more efficient water use by calves (Figure 1). Body weight and average daily gain were similar between treatments (Table 1). Feces tended to be firmer in calves on ROW, especially in the post-weaning period. Respiratory score had a tendency to decrease more over time when calves drank ROW (Figure 2). Respiratory score in calves fed ROW decreased during the transition period (week 6), which may indicate reduced weaning stress. Starter intakes also were less in the pre-weaning period, but more in the post weaning period for calves fed ROW compared to MCW. Despite lack of large differences in growth performance, it was found that even small improvements in water quality can result in improvements in calf health and wellbeing.
Table 1. Intakes, growth performance and health scores of calves.. Intakes, growth performance and health scores of calves.
Figure 1. (Above) Drinking water, total water and milk replacer water intakes for Holstein calves fed reverse osmosis water (ROW) and municipal city water (MCW).
Figure 2. (Above) Respiratory score for Holstein calves fed reverse osmosis water (ROW) or municipal city water (MCW) (Note: lower numbers indicate calves were healthier).
This research was funded by Culligan Water, Brookings SD with support by the South Dakota Agricultural Experiment Station at SDSU.
Results of this study will be presented in the Livestock Water session at the Joint Annual Meeting of ASAS and ADSA on July 21, 2016 in Salt Lake City, Utah.