The effect of coal mine pitwater on health and growth of steers

Abstract

Pi-m. Amt. Sot. Akm. Prod. 1994 Vol. 20 THE EFFECT OF COAL MINE PITWATER ON HEALTH AND GROWTH OF STEERS T.J. KING and R.A. HUNTER CSIRO Division of Tropical Animal Production, Tropical Beef Centre, Rockhampton, Qld. 4702 This study was undertaken to determine the effect of drinking high sulfate coal mine pitwater on the health and growth of beef cattle. The recommended tolerance of cattle to drinking water of high mineral content have been arbitrarily defined from field observations and as a guide sulfate is in the order of 1000 mg/L. National Water Quality Management Strategy (Anon. 1992) has highlighted the need for maximum permissible concentrations to be determined from rigorous experimentation. Twenty-eight Belmont Red steers with an initial mean liveweight of 212 2 13.5 kg were allocated equally on the basis of liveweight to 4 treatments; a control (town water); 500 mg/L, 1000 mg/L and 2000 mg/L sulfate. Coal mine pitwater containing 5580 mg/L sulfate, 4300 mg/L chloride, 2450 mg/L sodium, 458 mg/L calcium and 754 mg/L magnesium was diluted with town water to constitute the 3 treatment concentrations. Starting at an initial concentration of 500 mg/L sulfate the concentration was increased by 500 m&L every 7 days until the final treatment concentrations had been achieved. Each group of steers was housed in a pen in a roofed animal house and fed chaffed lucerne hay ad libit~.rm with unrestricted access to water in troughs. Throughout the entire experiment feed and water intakes were measured daily and liveweight recorded twice a week. After 91 days at final concentration 3 steers from each treatment were selected at random for post mortem examination. Histopathological examinations were conducted on 20 internal organs, skeletal muscle, adipose tissue and skin. The consumption of the different concentrations of coal mine pitwater had no effect on feed and water intake (Table 1). For each group there were no temporary fluctuations in intake as sulfate concentration increased. Liveweight increased uniformly in all treatment groups over the period prior to and after the final concentrations were imposed. No significant treatment differences were found in faecal dry matter concentration, packed cell volume or total sulfur concentration in plasma (Table 1). Post mortem examination and subsequent histopathological examination of tissues determined that no detectable changes had occurred in any of the steers. Table 1. Dry matter intake (g/kg liveweight.day), water intake (mL/kg liveweight.day), faecal dry matter (%), packed cell volume (%), concentration of sulfur in plasma (mg/L) and weight change (kg/day) of steers drinking various concentrations of sulfate as mine pitwater for the 91 days of final concentration The results of this experiment demonstrated that the health and growth of steers were unaffected by drinking coalmine pitwater diluted to 2000 mg/L sulfate. The financial support of BHP Australia Coal Limited is gratefully acknowledged. ANON. (1992). 112 'Australian Water Quality Guidelines for Fresh and Marine Waters', pp. 5-2 1 (Australia and New Zealand Environment and Conservation Council). 341