Changes in colored or flavored food preferences in chickens as a function of shock

Abstract

Twenty-four two-week old chicks were first tested to determine which of two mashes, differing either in color or found that avoidance reactions produced by electric shock to the paws of rats transferred to the audiovisual stimulus in a feeding situation but not to the actual taste of the food. Consistent with this, Braveman & Capretta (1965) reported that food preferences based solely on gustatory cues are more readily altered in rats when the conditioned association is one involving intubation of salt water as the noxious stimulus rather than pain from electric shock. The present study offers more direct information on the role of electric shock in the aversive conditioning of preferences for foods which themselves differ either in color or taste. It also adds to our knowledge of food habits in the chicken. METHOD Twenty-four White Rock chicks were hatched and housed together for five days, then placed in rows of individual cages (10 in. cubes) enclosed in a 9 ft x 4 ft x 5 ft high cubicle which was warmed to 80 ± 5 deg F and aired by a hair dryer. The fronts and bottoms of the cages were of 1/2 in. wiremesh, while the remaining three sides were of white painted hardboard, and the lids of clear plastic. In addition, each cage contained two clear plastic bird cups (Toppet 138 B), modified to prevent spillage, located on either side of a water tube. A shaded 75-W incandescent bulb located 20 in. above the center of the cages dimly illuminated the off-white cubicle during maintenance feeding. Two 80-W "natural" fluorescent tubes, running the full length of each row of cages, provided bright lighting for training trials and preference tests. An Applegate bipolar stimulator (Model 250) was used to deliver shock by means of electrodes taped to the chick's legs and passing through the bottom of the cage. The chicks were accustomed to the wires before training began. Two kinds of test foods were used: II of the chicks received commercial starter mash which had been dyed either red or green with 30 parts tap water to I part Kroger's food color; the remaining 13 chicks were given mash either sweetened by saccharin (starter mash first mixed in a .7% saccharin-water solution, then dried and crushed into its original texture) or left untreated. Those chicks receiving dyed test foods were maintained on ordinary starter mash at all times except during experimental sessions; whereas those experiencing flavored test foods received a maintenance mash consisting of corn meal (45%), starter mash (33%), cream of wheat (10%), hominy grits (10%), and salt (2%).Starting at 15 days posthatch, II Ss were tested for colored food preferences in a series of eight morning and afternoon sessions, each lasting 4 h. The remaining 13 Ss were pretested using the flavored foods. Equal quantities of the two test foods were placed in separate containers at the beginning of each test, and the amount eaten determined by weighing before and after each test. The position of the foods was alternated from session to session. Following pretesting, those c...

Appropriateness of reinforcement to cue in the conditioning of food aversions in chickens (Gallus gallus).

“…No ready explanation is at hand to account for the similiar changes in food preference found for both the experimental and yoked control groups. The importance of this effect is underscored by similar results reported in an earlier study (Moore & Capretta, 1968). It should be remembered that the yoked control birds in both studies were shocked in the absence of the test food; their colored and/or flavored foods were presented either before of after the actual training trials.…”

“…Furthermore, it seemed plausible that while taste and odor cues were more easily associated with gastrointestinal discomfort, visual and auditory cues were more readily attached to pain from electric shock (Garcia, Mc-Gowan, Ervin, & Koelling, 1968). Moore and Capretta (1968) supported this theoretical point in showing that young chickens given electric shock to their legs while eating the preferred of two foods evidenced lowered preferences when such preferences were based on color, but not on taste alone.…”

“…In an earlier study (Moore & Capretta, 1968), electric shock proved to be an effective noxious stimulus for lowering food preferences based upon color but not for those distinguishable by taste alone. In the present experiment food preferences based upon taste were likewise lowered when color cues were added to the gustatory cues during training.…”

“…Thus, no clear distinction is made between electric shock and, say, x-irradiation or saltwater preloads concerning their relative effectiveness as noxious stimuli in the alteration of food preferences. The results from a growing number of studies (e.g., Braveman & Capretta, 1965;Garcia & Koelling, 1966;Garcia et al, 1968;Moore & Capretta, 1968) showing that certain noxious stimuli fail to generate aversions to all of the test food cues require at least the hypothetical involvement of a notion of "stimulus relevance" (Capretta, 1961;Revusky & Garcia, in press). This idea has pointed up the greater likelihood of gustatoryolfactory cues becoming aversively conditioned to states of gastrointestinal discomfort, and auditory-visual cues to pain from electric shock (at least in the rat).…”

“…The purpose of this experiment was to determine whether an aversive association between electric shock and taste can be mediated by distinctive color cues present during training. It seemed likely that such an arrangement would result in the establishment of an aversive association between two stimuli (shock and taste) which were not so associated in the Moore and Capretta (1968) study.…”