Performance, Digestibility of Diet Constituents and N-Retention of Swine Fed Diets with Added Water

Two feeding and two metabolism trials were conducted to evaluate performance, digestibility of diet constituents, N-retention and physical carcass characteristics of swine fed diets with added water. In Trial I, 42 pigs averaging 16 kg., initially, were used to compare diets containing 10 (dry), 25, 40, 55, 70 and 85% water (weight basis). High levels of water in the diet (70 and 85%) depressed feed intake and daily gain, whereas feed efficiency apparently was impaired during the first 28 days of the trial but improved the second 28 days with no over-all difference. In Trial II, 30 pigs averaging 22 kg., initially, were used to compare diets containing 10 and 40% water. Dry matter intakes were equalized. Daily gain and feed efficiency data did not differ between pigs fed dry and 40% water diets. In Trial III, six barrows averaging 61 kg., initially, were used in a 3×3 extra period Latin-square to study performance of pigs and digestibilities of the proximate components when diets containing 10 (dry), 40 and 85% water were fed. Daily gain and feed efficiency were depressed and urine volume increased when pigs were fed a diet with 85% water. Serum protein levels and apparent digestibilities of dry matter, crude protein, ether extract, crude fiber and N-free extract were similar for all treatments. In Trial IV, eight barrows averaging 48 kg., initially, were used in a single changeover design with two extra periods to study performance of pigs, digestibility of dietary components and N-retention when dry and wet (85% water) diets were fed. Daily gain and feed efficiency were depressed and urine volume increased when pigs were fed a diet with 85% water. Dry matter, crude protein, ether extract and crude fiber digestibilities, and hematocrit and hemoglobin values were similar for both treatments. Energy and N-free extract digestibilities, and N-retention were less for pigs fed the 85%-water diet. Carcass measurements revealed no effect of treatment on dressing percent, backfat, carcass length or loin eye area. Neither the relative nor the absolute weights of the lung, liver, kidney, heart and spleen were different. Weights of viscera, stomach, small intestine and large intestine expressed as percentages of bodyweight did not differ.