Effects of sodium bicarbonate and potassium chloride drinking water supplementation. 2. Meat and carcass characteristics of broilers grown under thermoneutral and cyclic heat-stress conditions.

Two broiler trials were conducted to investigate the effect on post-mortem carcass and meat quality of NaHCO3 and KCl drinking water supplementation under thermoneutral and cyclic heat-stress climatic conditions. Water chill carcass weight change, water- and oven-cooked breast filled yields, and breast meat tenderness were measured. In Trial 1, neither environmental regimen, nor water treatments, nor their interaction was a significant (P less than .05) source of variation for the parameters measured. In Trial 2, environmental regimen was a highly significant (P less than .01) source of variability for chilled carcass weight change; the cyclic heat-stressed broiler carcasses gained more weight than the thermoneutral (control) broiler carcasses during ice-water chilling. Oven-cooked fillet yield was significantly (P less than .05) affected by environmental regimen; fillets from cyclic heat-stressed broilers had lower yields than thermoneutral (control) broiler fillets. Drinking water treatments were a significant (P less than .05) source of variation for breast meat tenderness in Trial 2. Broilers given .5% NaHCO3 from 5 to 8 wk of age had higher shear resistance values than broilers given a combination of .5% NaHCO3 and .5% KCl or tap water-fed controls. Breast meat shear values were negatively correlated (P less than .05) with 8-wk broiler body weight and 5- to 8-wk gain.