Food Insights Research Articles

The Forgotten War

The Forgotten War

Do more sociable dogs gaze longer to the human face than less sociable ones?

Domestic dogs (Canis familiaris) are especially skillful in communicating with humans, and they rely on special abilities to do that. One of these skills involves gazing at human faces in cases of uncertainty or when seeking for something out of reach. In this study, we evaluated the relationship between dogs' sociability level and the ability to learn to gaze in a situation with food in sight but out of their reach. Thirty-nine adult dogs were tested in two procedures: (1) a sociability test that involved interacting with an unknown person, and (2) a learning task that consisted of training trials in which gazing at the experimenter's face was food reinforced, followed by extinction trials in which gazing was not followed by food. A significant positive correlation was found between the duration of physical contact with the unknown person in the sociability test and gaze duration during extinction. Moreover, high sociability dogs gazed significantly longer at humans during extinction trials. We discuss the possibility that, more sociable animals, such as those who pay more attention to the person in our sociability test, may be more persistent in their communicative attempts because the presence of the human is intrinsically reinforcing to them. Finally, we comment on the importance of these findings for training purposes.

Treatment and follow-up of obesity in adolescent girls

An intervention program was conducted for 12 postmenarche, 12–15-year-old obese girls. Weight Winners, a multicomponent and multidisciplinary after-school intervention program, was developed in which behavior modification, aerobic exercise, and modeling appropriate behaviors for weight control were emphasized. Evaluation made before and immediately after the intervention and at a nine-month follow-up suggested that the after-school treatment program was successful in: 1) reducing the rate of gain and decreasing body weight by 11% while maintaining lean tissue and resting energy expenditure (REE), and 2) improving eating and exercise behaviors. Significant changes in eating behaviors ( p < 0.05) were: more low-calorie, nutritionally dense foods were consumed; the frequency and amount eaten decreased; and the speed of eating slowed. Implementing a fee contingent on attendance and on record keeping appeared to reduce attrition. Subjects cited the Weight Winners program, aerobic exercise, changes in eating behaviors, group and family support, and encouragement and praise from the group leaders as important contributions to their success in weight control. Barriers to change were reported by participants as boredom, hunger, lack of family and peer support, and having food in sight. An increase in lean tissue was associated with both improved self-esteem ( p < 0.05) and improved self-control ( p < 0.05). Subjects who had been obese the longest were the most responsive to hunger cues ( p < 0.05).

Lack of a Cephalic Phase of Gastric Secretion in Chickens

Cannulae were surgically implanted in the caudoventral margin of the glandular stomach of 10 Single Comb White Leghorn hens to permit collection of gastric secretions. A total of 44 experiments was performed. The hens were fasted for 24 hr after which secretions were collected separately for three 20-min periods with 1) no food in sight, 2) food in sight but unavailable, and 3) food available. The volume, pH, and pepsin content of the secretions were not significantly changed between Periods 1 and 2, indicating no cephalic phase of gastric secretion. Secretory activity was significantly different between Periods 2 and 3, demonstrating the presence of a gastric phase of gastric secretion.

Cephalic control of avian gastric secretion

Abstract 1. 1. Turkeys, chickens, great-horned owls and red-tailed hawks were surgically fitted with a cannula in either the glandular stomach (fowl) or muscular stomach (raptors) to permit collection of gastric secretions. 2. 2. After 24 hr of fasting, secretions were collected during three successive periods of no food in sight, food in sight but unavailable and food available. 3. 3. Neither gastric secretory volume nor pH was influenced by the sight of food for domestic turkeys, floor-raised domestic chickens, or red-tailed hawks. 4. 4. Gastric secretory volume increased significantly from 1.08 to 1.47 ml/kg (45-min collection period) when food was in view but unavailable for great-horned owls. 5. 5. Increases in volume and pH which occurred when food was consumed were accounted for by ingestion of food and water, or fluids in the meat eaten by the raptors.