- 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), sodium chloride (NaC1), acetic acid (HAc) and quinine
hydrochloride (QHCI). 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. Goats were
allowed two-day test periods per concentration; sheep and cattle
were given one-day test periods.
Mean responses and standard deviations of the eight-animal
groups were plotted graphically and compared to threshold levels of
intake. 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 (UPT) 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
were identified by and , respectively.
Molar concentrations of thresholds crossed by responses of
pygmies, normals, sheep and cattle, respectively, were for Suc,
UDT; .055t and .53k; UDT: .033t, PRT: .38t; LDT: .41;
UDT: OZSt and . 4U, PRT: . 058f and .24, LDT: . 56; for
NaC1, UDT: .024t and .Z1, PRT; .iot and ,14, LDT: .36L
RET: , 60; UDT: . 0Z7, LDT: . 15L RET: . 55; LDT: .21,
RET: . 53 ; LDT: , 016, RET: , 14; for MAc, UDT: . 0034t
and .04Z, LDT: .l6, RET: > ZZ; LDT: .014, RET: .11;
UDT: .0034t, LDT: .028, RET: .094; UDT: .0017t and
.0069j, LDT: ,014, RET: .038'; and, for QHCL, UDT: >
.000016t and .000047,, LDT: .00030, RET: .00202; UDT:
.000016t and .000063, LDT: .00035, RET: .0020Z; LDT:
,000094, RET: .00035k; LDT: .00013 , RET: .000381.
In general, stimulating effectiveness was greatest for bitter,
followed in order by sour, salty and sweet. Cattle were usually first
to make a discrimination, goats were generally second and sheep
were normally last. The major exception was for the bitter taste
group where the order was goats, sheep, cattle. As a rule, goats
were more tolerant of high concentrations than were sheep and sheep
were more tolerant than cattle. The exception was, again, the bitter
taste group where the order was goats, cattle, sheep.
Sheep were indifferent to 2. 08 and 8. 33% molasses concentrations.
Cattle demonstrated stroxg preference respoises to the
2. 08% level and weak preference reactions to the 8.33% level.