22. Beef Nutrition 2

1. based on air temp, moisture, and air speed

2. can affect energy needs

what is effective temperature

increases

cold stress like cold and wet conditions will (increase/decrease) energy requirements beyond maintenance

hair coat, moisture, and wind

what does lower critical temperature (LCT) depend on

1%

energy will increase __% per degree below lower critical temp (LCT) when conditions are dry

2%

energy will increase __% per degree below lower critical temp (LCT) when conditions are wet

5-6BCS

what BCS is ideal for beef cattle when going into winter

insulation

amount of body fat (BCS) is equal to the amount of...

forages

do forages or grains result in more heat production

when on poor quality forages

in what situation can grains increase heat production

1. 1-9 scale

2. palpation and visual fat deposition

3. target is 5-7 (6 ideal) at breeding and calving

what are some characteristics of beef cattle BCS

1. time to first estrus...shorter interval to first heat w/ higher BCS

2. colostrum quality is higher when a higher BCS

3. calf immunity...higher IgG w/ calves born to cows with higher BCS

what are some things BCS can affect

BW fluctuations due to changes in gut fill

why is BCS a better indicator for performance than BW in ruminants

decreased pregnancy rate

what will low or high (outside of 5-7 range) do to pregnancy rate

group according to BCS so you can feed based on the amount of condition needed

what is the ideal method to house cows after calving and why

65%

for heifers, target ___% of mature BW at breeding

85%

for heifers, target ___% of mature BW at calving

14-15 months

what is the ideal age for heifers to hit puberty...based on BW

1. 1100 X .65 = 715 lb target at breeding

1. 1100 X .85 = 935 lb target at calving

what would be the target BW for a 1100 lb heifer at breeding and at calving

1. avoid overfeeding energy

2. 11% CP

3. NEg based on ADG target

what are the key points of heifer nutrition

1. process to reduce stress and improve health before feedlot entry

2. goal to reduce health issues in feedlot, improve growth post-weaning, and enhance overall profit

what is the point of preconditioning of weaned calves

1. health and welfare aspects like castration, dehorning, and deworming

2. vaccination such as 2 sets of respiratory (MLV) and clostridial vaccines

3. bunk training to use feed and water troughs

what tasks are to be completed in the proconditioning process

30-45 days

at the end of preconditioning, it is ideal to have ______d low-stress weaning prior to shipping through methods like fence-line weaning

1. preconditioned

2. individual ID

3. source/age verified

4. proper injection practices...done in front of shoulder to preserve muscle

what are the key results of preconditioning that lead to a "value-added calf"

>$30/calf

what is the typical return for a value added calf

5-7 BCS

what is the ideal BCS for beef cattle at calving

1. ADG >0.5lbs/d

2. low quality hay

3. winter or later summer

when is supplementation needed for stockers when trying to support adequate growth

1-2.5 lb/d per animal

what is the grain supplementation range for stockers

mostly pasture with occasional supplemenation

how might you describe the diet of stocker cattle

dry lot on a hay + grain mix

how might you describe the diet of backgrounding cattle

>8% CP

what is the forage CP requirement for stockers in order to maintain rumen microbes

12-16% CP

what is the diet target CP in order to support adequate growth of stockers

ensure that some essential AA reach the animal

why is UIP/by-pass protein often needed in the diet of stocker cattle

1. do NOT use with high forage diets

2. can use on high energy (grain) diets

what are the stipulations for supplementing urea in the diet of stocker cattle

forage diets are digested too slowly relative to energy content for urea to be utilized

why can we NOT supplement urea in stocker cattle when they are on high forage diets

protein

___ often limits growth on low-quality forage and most forage in general does not meet the requirements

700-800lbs

at what weight do beef cattle enter the feedlot

1. acidosis

2. laminitis

3. liver abscesses

what are the risks of high grain diets in feedlot cattle

9-14%

what is the CP requirement for feedlot cattle...cold be higher at first then step down CP in final diet hence the range

Ca

what mineral requires supplementation in feedlot cattle due to low amounts of it in the grain they are consuming

1. adapt rumen microbes to a high grain (starch) diet over 3-4wks time

2. maintain intake

3. prevent acidosis via slow adjustments

what is the goal of the feedlot transition diet

60% forage/40% concentrate

when changed the diet of beef cattle what is the ideal way to start...

90% concentrate

what will the diet of feedlot cattle look like at the end of the diet transition

gradual transitions

by what method do we prevent rumen upset when changing the diet of beef cattle

1. consistency is key...fresh and delivered on time

2. monitor intake

3. feed ad libitum but mimimize waste

what are the key characteristics of feed bunk management

want a little bit of feed left after they finish eating....shows they are eating all they can

what is the point of ad libitum feeding of beef cattle

12-16%

what should the level of CP be overall in the diet of growing stocker cattle

1. K is high in forages and can interfere with Mg absorption

2. Mg is low in spring grasses...need to supplement

what are some of the things that can cause Mg deficiency and ultimately lead to grass tetany in cattle

grain high in P which upsets the Ca:P ratio

what causes urinary calculi in beef cattle

1. pasture fertilization causes plants to accumulate nitrates

2. weeds possess nitrates

3. nitrates will form methaemoglobin can inhibit O2 transport

how does nitrate lead to toxicities

calves

mycotoxins (found in corn feeds and corn silage) is a bigger issue for (calves/cattle) and causes decreased DMI and growth

1. acidosis (usually acute) due to lactic acid accumulation

2. bloat in frothy or free gas form

what are some the rumen disorders in beef cattle

sulfur-associated polioencephalomalacia

what condition is associated with sulfur toxicities in beef cattle

sourced from distillers grains and risk associated with variability in S content

where is sulfur sourced from and what is the risk of it....

1. 0.18-0.24% required

2. 0.4-0.5% toxic

what is the required vs toxic dose for sulfur in cattle

high sulfur in diet will increase demand for thiamine therefore leading to secondary thiamine deficiency over the course of 1-4wks

how does sulfur-associated polioencephalomalacia actually occur

1. estrogenic: estradiol, progesterone, zeranol

2. androgenic: testosterone, trenbolone acetate

what are the different hormonal implants we use at any stage for growth or finishing in beef cattle

15-20%

hormonal implants will increased ADG by ___% to put more mm. on the cattle

MGA (melengestrol acetate)

this progesterone analog will suppress estrus in heifers....important because estrus will decrease DMI

1. optaflexx/ractopamine--->repartitioning agent

2. more mm. deposition compared to fat

3. banned in many places

what are some characteristics of beta-agonists as growth promotants in beef cattle

coccidiostats

this growth promotant is used in young cattle and feedlot cattle against naturally occurring coccidiosis to improve ADG and feed efficiency

shift rumen fermentation to decrease acetate and methane and INCREASE PROPIONATE

what is the mechanism of ionophores in cattle

deposition of mm. instead of fat by decreased acetate

the result of ionophore rumen shift is to direct metabolism towards...

1. increase feed efficiency

2. decrease acidosis

what are the benefits of ionophores in beef cattle

1. environment and BCS strongly influence requirements

2. nutrition varies by production stage

3. feedlot transitions must be gradual

4. many diseases are nutrition related and preventable

what are some summary points for beef cattle nutrition