Ingestive behavior and physiological parameters of Sindhi heifers receiving saline water.

The objective was to evaluate the effects of potential use of brackish water as a source for Sindhi heifers on ingestive behavior and physiological and serum parameters. Twenty-four Sindhi heifers were distributed in a completely randomized design with four treatments and six replications, with levels of total dissolved solids (TDS) of 640, 3200, 5760, and 8320 mg/L. Three 24-hour behavioral tests were performed, which were divided into four observation shifts (00:00 to 06:00; 06:00 to 12:00; 12:00 to 18:00 and 18:00 to 00:00) at the beginning, middle, and end of the experiment. The highest values of black globe temperature humidity index and air temperature were observed at 14:00 h, with values of 92.7 and 34.1 °C, respectively. The different levels of TDS did not promote significant differences (P > 0.05) in the variables feed intake, rumination, idling, feeding efficiency as a function of dry matter and neutral detergent fiber intake, rumination efficiency as a function of dry matter and neutral detergent fiber intake, heart rate, rectal and surface temperature, creatinine, and potassium. Among the assessed shifts, feed and water intake showed higher frequencies in the shifts 2 (06-12 h) and 3 (12-18 h) and rumination showed a higher frequency in the shifts 1 (00-06 h) and 4 (18-00 h). The physiological variables presented higher indices during the warmest hours of the day. A linear behavior was observed for the serum sodium level, presenting a average of 134.4 mmol/L. Water containing up to 8,326 mg/L TDS can be used in the watering of Sindhi heifers in short periods in the season of highest water shortage without affecting the ingestive behavior and physiological and serum parameters of the animal.