The effect of water quality on nutrient availability for grower/finisher pigs

Abstract

Two 6 × 6 Latin square experiments were conducted with male grower/finisher pigs (initial weight approximately 45 kg) to determine the effects of increasing levels of total dissolved solids (TDS) in water on the partitioning of nutrients from the diet. The first experiment consisted of six water treatments, 0 (distilled water), 370 (tap water), 1000, 4000, 6350, and 8000 ppm TDS. The increased TDS levels were obtained by the addition of sodium bicarbonate, sodium chloride, and sodium sulphate (in the ratio 3:3:1) to the tap water. At these levels there was no significant treatment effect (P > 0.05) on growth rate (GR), digestibility of energy (DE) or crude protein, or metabolizable crude protein. As water TDS increased, metabolizable energy (ME) decreased (P < 0.05) from 3150 kcal kg−1 to 2932 kcal kg−1. In the second experiment, six water treatments were prepared by the addition of magnesium sulphate, sodium sulphate, and sodium chloride (in the ratio of 3:3:1) to tap water (450 ppm TDS) to obtain water containing 1100, 4000, 7000, or 11 700 ppm TDS. Distilled water (0 ppm TDS) was used as a control. No significant treatment effect (P > 0.05) was observed for water intake, urinary output, GR, DE, ME, or metabolizable crude protein. However, sulphates at 11 700 ppm TDS significantly decreased (P < 0.05) the digestibility of dry matter and crude protein. Mineral excretion, in feces and urine, and retention were also examined in both experiments. Key words: Water quality, pigs, salinity, digestibility, minerals