Exam 2

Question 1

cool season annuals

Answer 1

most common in bama. rye, ryegrass, wheat, oats. rye/ryegrass combination common (clover). supplement and hay needed 30-45 days during winter. stocking rate: 1.25-2 calves/acre. ADG = 1.3-2.2 lb/day. keep it vegetative for longer grazing period.

Question 2

cool season annuals with supplemental ration

Answer 2

several possibilities. limit feed soyhulls or other by products. corn and broiler liter 50:50 fed free choice. SR= 2-2.5 or greater. good system for forage management. winter = eat more supplement. spring = forage not in excess. ADG = 2-2.2 lb/day

Question 3

perennial pasture + winter hay

Answer 3

fescue, orchardgrass. + clover is economically beneficial. SR = 1.2-1.5. orchardgrass ADG = 1.5-1.6 lb/day or 1.8-2 with clover. fescue ADG = .5-1.1 lb per day with endophyte infected. 1.5-2.1 lb/day w/ noninfected.

Question 4

dry lot using by product feeds and grain or corn silage as major feed source.

Answer 4

calves weighing 450-500 lb will each 28-30 lb silage, 3-4 lb corn, 1-1.25 lb protein supplement. ADG = 1.75-2.2 lb/day. have cattle of dry lot and forage in another, chop what you need then go feed it.

Question 5

tall fescue overview

Answer 5

from europe / kentucky hillside. widely adapted (35 million acres). long growing season.

Question 6

tall fescue problems

Answer 6

fescue foot (also may lose switch, tips of ears - vasal constriction problem). fat necrosis. fescue toxicosis.

Question 7

fescue toxicosis

Answer 7

lack of heat tolerance, failure to shed hair coat, steer gains reduced .1 lb/day for each 10% of plants infected. fungus = neotyphodium coenophialum. endophyte, transmitted through seed, produces ergot alkaloids (protects plants, toxic to livestock).

Question 8

tall fescue producer strategies

Answer 8

avoid the endophyte (especially mares), minimizing grazing in hot weather. in new plantings use non-infected seed, but less stress and insect tolerant. manage to reduce stress due to endophyte, keep fescue defoliated (but dont overgraze), prevent grazing seed heads (mow if necessary), dewormers seem to reduce negative effects on steer gains. dilute the toxicants, grow a legume with the fescue, use other feed sources (non-fescue hay, grain)

Question 9

novel endophytes

Answer 9

endophyte that helps the plant but does not hurt the animal. Max Q - nontoxic fungus in new fescue varieties such as jesup. animal performance similar to non-infected fescue. it is persistant.

Question 10

margin and market timing

Answer 10

seasonal price changes affect margin. compared to feedlot, have less gain with stockers to overcome negative margin. take advantage of normal yearly price cycles, higher spring proces help narrow the negative price margin. work up a budget, mandatory, should not be locked into a single type of marketing program.

Question 11

rate of gain

Answer 11

type of cattle purchased, growthy, light for frame size. quality and amount of feed. growth promotants and ionophores, usually see additive effects. growth promotants increase ADG ~.2-.3 lb/day (synovex S&H; Ralgro; Compudose; dont use in replacement heifers). Rumensin and Bovatec increase ADG ~.1-.2 lb/day.

Question 12

Value of added gain

Answer 12

if cattle sell for $75/cwt, value of added gain is not $75/cwt. determine the feasibility of supplementing for faster gains or for more gain. 700 lb cattle for $106/cwt = $742. 750 lb cattle for $102/cwt = $765. difference = $23. $23/50 lb gain = $.46/lb gain.

Question 13

length of ownership

Answer 13

most costs occur before or shortly after calves are purchased. certain amount of total gain required to recover all costs. short periods of ownership must be accompanied with fast gains. no rain in fall, cold winter, no grazing until feb, probably no profit.

Question 14

health of cattle

Answer 14

number of ownership changes, sale barns, shipping fever, etc. have a good health plan.

Question 15

budget - gross receipts feeder calves

Answer 15

(final weight * survival) * (price per unit/100)

Question 16

budget - income above variable costs

Answer 16

gross receipts feeder calves - total variable costs

Question 17

budget - net income

Answer 17

gross receipts feeder calves - total costs

Question 18

budget - net value/cwt gain (final-initial values /cwt gains)

Answer 18

(gross receipts feeder calves - stocker calves costs) / cwt gain

Question 19

budget - cost/cwt gain over variable costs

Answer 19

(total variable cost - stocker calves cost) / cwt gain

Question 20

budget - cost/cwt gain over total cost

Answer 20

(total cost - stocker calves cost) / cwt gain

Question 21

budget - breakeven price (per cwt) over variable cost

Answer 21

total variable costs / ((final weight*.985)/100)

Question 22

budget - breakeven price (per cwt) over total costs

Answer 22

total costs / ((final weight * .985)/100)

Question 23

reticulum and rumen

Answer 23

reticulo-rumen. infection may occur if hole happens and bacteria leaks out. microbial fermentation. on left side.

Question 24

omasum and abomasum

Answer 24

omasum is like many leaves /pages. called many plies. omasum primarily absorbs water. abomasum is true stomach. it secretes acid, emulsifies fats. on right side.

Question 25

displaced abomasum

Answer 25

gas accumulation, then slips under rumen, gets stuck and will not have food passage.

Question 26

anaerobic fermentation

Answer 26

25-50 billion bacteria / ml. 200,000 - 500,000 protozoa / ml. high grain diet = more acidic, so protozoa is low. all forage diet = protozoa high.

Question 27

reticulum

Answer 27

particle size is important in allowing feed particles to pass to the omasum. average retention times.. 48-52 hr for roughage (longer for poorer quality). 18-22 hr for grains. cows spend ~8 hr/day rumenating. feed is layered = smaller particlesl and liquid at bottom, most bacteria. top is mostly undigested.

Question 28

digestion in general

Answer 28

cellulose and other fiber components slowly degraded. starch (in grains) more rapidly degraded (bacteria preferentially degrade starch before cellulose). protein in immature forages degraded fairly rapidly. protein in mature forages degraded more slowly (lower digestibility)

Question 29

microbial fermentation of feeds

Answer 29

anerobic. no O2 so no mitochondria. have glycolytic pathways (anerobic). no TCA cycle or ELS. cant oxidize carbs to CO2 and water. glucose to glycolysis to pyruvate to alternate pathways.

Question 30

volatile fatty acids

Answer 30

acetate, propionate, and butyrate. these 3 makes up the most energy. propionate main source of carbon for glucose. primary source of carbon for fat is acetate and butyrate. ionophore changes microbial fermentation in favor of propionate.

Question 31

weaned calves vs feeder calves and urea

Answer 31

limit to size of rumen in weaned calves, do not make enough microbial protein for AA, so need escape protein to make up for it.

Question 32

feeding urea

Answer 32

feedlot cattle, up to 650-750 lb, use natural protein (cant consume enough to meet protein needs). >650-700 lb, urea = natural protein as n source. above .75% urea in diet DM, start observing palatability problems (decrease intake). general recomendation is do not exceed 1% urea in diet. ,ight cause toxicity.

Question 33

reasons to supplement cattle on forage diets

Answer 33

provide a better balanced supply of nutrients to the animal. enhance forage digestibilty and increase intake by the animal. increase carrying capacity of pasture. stretch forage supplies. provide a carrier for growth promotants, ionophores, anthelmintics (dewormer), and bloat control.

Question 34

goal of supplementaion should be

Answer 34

to optimize forage utilization, and avoid or minimize substitution of forage with supplement.

Question 35

low quality forages and protein supplements

Answer 35

increase digestibility. increase rate of passage (decrease retention time). increase intake. resultin gin increased gains, and weaning weights, beter body condition, and increased reproductive efficiency.

Question 36

positive associative effect

Answer 36

you got more output than input

Question 37

low quality forages and grain supplements

Answer 37

performance usually not as great as expected (may take > 12 lbs grain to produce 1 extra lb gain). performance may be worse than that for nonsupplemented cattle. caused by overall decrease in energy intake. may not be giving them enough to make up the difference of what they are not eating. longer retention time so stay full longer.

Question 38

causes of inefficient response to energy supplementation

Answer 38

reduced fiber digestibility (starch is preferably fermented). substitution of grain for forage.

Question 39

cool season forages (high quality)

Answer 39

nutritional content high. 20-30% protein. ~70% TDN. very digestible (~75%). should not be nutrionally limiting for stocker cattle. but steer ADG normally 2.4 lb or less.

Question 40

supplement concepts different from lower quality forages.

Answer 40

protein in cool season forages is rapidly degraded by rumen MO. ruminants dependent on microbial protein to meet protein requirements. protein in cool season forages is rapidly degraded by rumen MO. Problem: inadequate available energy to utlize forage N for microbial protein synthesis, thus much of forage N lost in urine.

Question 41

supplements for coos season forages should

Answer 41

reduce excessive degredation of forage proteins. provide readily available energy for microbial protein synthesis. contain proteins not readily degraded in rumen.

Question 42

provide energy to utlize degraded N

Answer 42

available energy for MO. amount of corn (and presumable other grains) is important. .4-.6% of body weight seems to be good recommendation

Question 43

efficiency of added gain

Answer 43

below .6% of BW, expect 5-6.5 lb grain per added lb gain. greater than .75% og BW too 9-20 lb grain per lb added gain. approx. 1-to-1 substitution of grain for forage. ADG improved, but it took more grain per kg added grain.

Question 44

hugh fiber by product feeds

Answer 44

contain structural CHO that are highly digestible. can provide fermentable source of energy without a drop in rumen pH.

Question 45

summary thoughts

Answer 45

types of supplements used vary widely. intake and digestibility can be increased, reduced or unaffected by supplements. livestock production usually is either enhanced or unaffected by supplements. small amounts of supplements can have large benefits.