Ans 214 SI Session 28

AnS 214 SI Session 28

Wednesday, 11/18, 8pm

A. Intake overview

1) List the 6 factors influenced by feed intake levels.

1.
2.
3. / 4.
5.
6.

2) What are the 4 variable that influence levels of feed intake?

3) As the number of stressors increases, what happens to feed intake?

4) Use the graph at right to diagram the relationship between stressor number and 1)protein deposition 2) fat deposition.

5) What environmental conditions and temperature range promote the highest level of intake?

What % of regular intake can these values reach?

6) At this same temperature range, what environmental conditions will cause a steep drop in feed intake?

7)As average temperature increases, feed intake ______. A cool night with hot days will result in a ______drop in feed intake, than a hot night with hot days.

B. Influence of feed characteristics on intake.

1) Name 7 characteristics of feed that have an impact on intake.

2) Impulses from which part of the hypothalamus signal satiety?

Hunger?

3) In ruminant animals, reticulo-ruminal signaling of fill to the hypothalamus is mediated by ______located in the cranial sac of the rumen. Fill in these compartments are determined by the rate of ______and the rate of ______.

4) What role does the abomasum play in the intake regulation of calves?

Adult animals?

5) What three specific feed characteristics influence reticulo-ruminal fill?

6) What are three commonly used feed processing methods?

What is the effect of physical modification of feed?

7) Other than fill, what other factor affects overall energy intake? Based on this factor, a diet rich in what macronutrient would result in the lowest intake?

8) Given the choice, animals will choose feeds with ______energy densities. Fill has a ______influence on feed intake than energy density. However, many animals will overeat energy, if it is required to satisfy their net ______requirement.

9) The 4 effects of fiber on intake and appetite are ....

10) Palatability influences that degree of feed ______. Appealing smell, taste and textures will increase palatability, while compounds such as ______, ______, ______will cause feed avoidance. Palatability can be increased by the addition of ______.

C. Appetite Control

1) What effect does gastric peristalsis have on hunger control?

2) What are the 3 modes of communication influencing appetite control?

3) For each of the tissue types below, indicate what appetite-controlling chemicals are manufactured.

Pancreas:

Adipose tissue:

Brain (3):

Stomach and intestines (4):

4) Satiety signals are generated both before and during meals in order to relay to the brain the ______and ______characteristics of the feed. These are conveyed by sensory neurons in the ______and ______nerves into the brain stem.

5) Name the 3 hypothalamic centers involved in appetite control.

6) Animals with lesions in the ______center of the hypothalamus have uncontrollable intake and become obese because they are unable to feel ______. Animals with lesions in the ______center of the hypothalamus stop eating and waste away because they are unable to feel ______.

7)Refer to the website for a table of in the hormones and neuropeptides involved in appetite control. Fill it in as a study aid.

8) Orexigenic hormones/neuropeptides ______appetite and ______energy expenditure. Anorexigenic hormones/neuropeptides ______appetite and ______energy expenditure.

Examples of orexigenic hormones:

Examples of anorexigenic hormones:

9) What are the 4 hormones involved in neuropeptide secretion?

10) What is the effect of leptin and insulin on POMC/CART neurons? NPY/AgRP neurons?

What net effect does this have on appetite?

What other hormone has a similar effect on appetite? What is its MOA?

11) How does ghrelin increase appetite?