Taste Responses in Ruminants. III. Reactions of Pygmy Goats, Normal Goats, Sheep and Cattle to Sucrose and Sodium Chloride

Abstract

This study involved the use of the two-choice preference test to determine the taste responses of eight, each, of pygmy goats, normal goats, sheep and cattle to ascending concentrations of sucrose (Suc) and sodium chloride (NaCl). In addition, sheep and cattle were tested at 2.08 and 8.33% molasses concentrations. Each animal was individually penned and fed to appetite on a nutritionally adequate diet. Responses were expressed on the basis of percent of total fluid intake comprised by test solution. Response trends were analyzed by stepwise multiple linear regression. A 95% confidence interval was established for a theoretical mean intake of 50%. The upper confidence limit was at 60% intake and the lower was at 40% intake. They were termed, respectively, upper discrimination threshold (UDT) and lower discrimination threshold (LDT). The rejection threshold (RET) was set at 20% intake and the preference threshold (PRT) at 80% intake. Ascending or descending responses at the various threshold concentrations are identified by ↑ and ↓, respectively. Molar concentrations at the thresholds crossed by responses of the species studied were, for pygmies, Suc—UDT: .055↑ and .53↓; NaCl—UDT: .024↑ and .21↓, PRT: .10↑ and .14↓, LDT: .36↓, RET: .60↓,, for normals, Suc—UDT: .033↑, PRT: .38↑; NaCl—UDT: .027↑↓, LDT: .15↓, RET: .55↓, for sheep, Suc—LDT: .41↓; NaCl—LDT: .21↓, RET: .53↓, and for cattle, Suc—UDT: .025↑ and .41↓, PRT: .058↑ and .24↓, LDT: .56↓; NaCl—LDT: .016↓, RET: 14↓. Sheep were indifferent to 2.08 and 8.33% molasses concentrations. Cattle demonstrated strong preference responses to the 2.08% level and weak preference reactions to the 8.33% level.