Food choice experiments

Beaver picking up experimental sticks in a food choice experiment. The animal will transport the sticks through the water to the lodge. There one or more beavers will consume the bark. The peeled sticks will be released into the water and can be found floating or stranded in the dam... 

Herbivores such as deer, bovids, rodents, or marsupials encounter a great diversity of plant secondary metabolites (PSMs). These PSMs greatly affect the food choices these animals make. In turn, herbivores affect plants by stimulating induced defenses as a consequence of browsing. For food choice experiments in the wild we need animals that can be found predictably in certain places at certain times. The beaver (Castor canadensis or C. fiber) is such a species. Beavers stay year-round near their lodges and readily accept food provisions. 

In this cafeteria-style food choice experiment, we will provide beavers with a range of woody plants, determine their choices, and interpret the results in terms of palatability, determined by chemical plant defenses and nutrient content. 

Grunert K G and Andersen S (2000), Purchase decision, quality expectations and quality experience for organic pork , 9th Food Choice Conference, Dublin, Trinity College, 28-31 July. 

Available choice of food plant species Many species R avoided only when food choice is wide Common experience... 

A second example of an activated chemical defense concerns the Indo Pacific sponge Aplysinella rhax, in which tissue damage results in the rapid enzymatic transformation of psammaplin A sulfate 63 into psammaplin A 64 exposure of 63 to tissue from other sponges does not result in any conversion. Compound 63 deters feeding by reef fish, but when offered a choice between psammaplin A and its sulfate, both foods were avoided. In aquarium assays with C. solandri, extracts of damaged tissue were more deterrent than extracts from intact tissue, but both treatments were less palatable than control foods. In choice experiments, C. solandri preferred food treated with 63 over 64.104... 

For most vertebrate herbivores, the ways they manage to avoid, tolerate, or detoxify their dietary allelochemicals have not been explored. Sometimes, only domesticated animals were used in experiments, but they tend to make more mistakes in food choice than the wild animals. 

Unlike many other mammals, squirrels are active during the daytime. We can observe their choices directly, or simply by the results of their actions, here the food choices they made. In North America, the ubiquitous squirrels and chipmunks offer themselves for behavioral experiments in backyards, city parks, cemeteries. National and State parks, and on college campuses. There the animals are conditioned to humans so that experiments can be carried out without disturbing their behavior. 

Below I present some results from earlier experiments in our courses. These are meant only as benchmarks. Each locale is unique in terms of trees present, or trees preferred. Also, season will affect food choice. The first graph (Fig. 8.1) shows... 

Thacker RW (1996) Food choices of land hermit crabs (Coenobita compressus H. Milne Edwards) depend on past experience. J Exp Mar Biol Ecol 199 179-191... 

HISTORY. In the United States, the bread-and-flour-enrichment program has been a controversial one. Some have maintained that the public should be educated to the use of natural foods that would supply all nutrients, but experience of centuries has shown that people are reluctant to change their food habits and that education regarding food choices is a slow process. A classical, pioneering rice enrichment experiment in the Philippines demonstrated how an action program can combat a widespread deficiency disease. 

Ezetimibe interferes with the absorption of cholesterol from the brush border of the intestine, a novel mechanism that makes it a good choice for adjunctive therapy. It is approved as both monotherapy and for use with a statin. The dose is 10 mg once daily, given with or without food. When used alone, it results in an approximate 18% reduction in LDL cholesterol. When added to a statin, ezetimibe lowers LDL by about an additional 12% to 20%. A combination product (Vytorin) containing ezetimibe 10 mg and simvastatin 10, 20, 40, or 80 mg is available. Ezetimibe is well tolerated approximately 4% of patients experience GI upset. Because cardiovascular outcomes with ezetimibe have not been evaluated, it should be reserved for patients unable to tolerate statin therapy or those who do not achieve satisfactory lipid lowering with a statin alone. 

Methods and Experimental. In the study reported by Beecher et al. (17), nine men aged 23-39 years served as subjects. On the day prior to the initiation of the first experiment, the subjects selected their day s meals from a limited menu. The quantity and choice of foods were then repeated on each subsequent pre-experimental day. The subjects fasted overnight, voided upon rising and then drank 300 ml of water. Upon arrival at the research center (0730-0830 hrs), fasting blood was drawn and urine collected. The subjects then ingested one of the liquid meals and drank 200 ml of water. The subjects also drank 200 ml of water each 1/2 hour during the duration of the experiment to induce diuresis. Blood was drawn at 1/2, 1, 2, and 3 hours post-meal urine was collected at each 1/2 hour for 3 hours post-meal. Seven to 14 days elapsed between experiments. 

Experiments have been tried in which small children have been given a free choice of good wholesome foods, with the result that they all chose somewhat differently and all thrived. But babies will get along reasonably well on many different assortments of wholesome foods, and so these experiments do not tell us as much as we would like to know. The question arises as to what would happen if babies were given free choices, not only of approved foods and food mixtures, but also, for example, of candy and sweetened and unsweetened alcoholic beverages. Would their wisdom of the body triumph The answer is almost certainly that some babies would show vast superiority over others both in their wisdom in shunning... 

Feeding repellents for pest birds are the most important application of chemical stimuli to manipulate bird behavior. Methyl anthranilate (Fig. 13.1) and dimethyl anthranilate, esters of benzoic acid, are found in concord grapes and are used as artificial flavorings. Starlings, Sturnus vulgaris, have an aversion to methyl anthranilate, which irritates the trigeminal nerve, and they feed less on food flavored with a variety of anthranilates. They avoid the more volatile anthranilates most. The odor is partly responsible for the effect contact is not necessary. In one particular experiment, only volatile compounds were aversive (Mason and Clark, 1987). If only anthranilate-treated food is offered, the birds will accept more of the flavored food than they do if they offered a choice between... 

The most frecjuent measurement or observation made is whether aniiiHls consune tannin-rich food in preferenco to tannin-pcor (or tannin-free) fcxxd. In a "no choice" feeding experiment this may be reflected in reduced or enhanced food consumption when experimental... 

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