1. Beef Cattle Nutrition

2. Beef Cattle Nutrition diagram of ruminant-handout
Esophageal groove – immature ruminants
Rumen, omasum, abomasum and reticulum
Small Intestine-duodenum, illeum, jejunem
Large Intestine-colon, cecum, rectum

5. Digestive System stomach in ruminants comprises 25 % of body
rumen comprises 75 % of stomach
fermentation: digest cellulose, plant tissue, urea, NPN, B & K vitamins
consist of bacteria and protozoa (200 billion/teaspoon)

6. Characteristics of Ruminants
Mouth
no upper incisor or wolf teeth
use lips and tongue to grab food
four compartments to the ruminant
Consist of microorganisms
Produce Volatile Fatty Acids/ acetic, propionic, butyric

7. Volatile fatty acids (VFA)
Produced in large amounts through ruminal fermentation and are of paramount importance in that they provide greater than 70% of the ruminant's energy supply. Virtually all of the acetic, proprionic and butyric acids formed in the rumen are absorbed across the ruminal

8. VFA’s cont.
epithelium, from which they are carried by ruminal veins to the portal vein and hence through the liver. Continuous removal of VFA from the rumen is important not only for distribution, but to prevent excessive and damaging drops in pH of rumen fluid.

9. Ruminants Prehension- the process of gathering food to the mouth
Mastication - the process of chewing
Eructation (belching of gas)
Carbon DiOxide and Methane
Enzymes- organic catalyst which speed up a biochemical reaction without being used up

10. Rumination Rumination-fermentation
rechewing usually > 8 hours/day dependent on diet (increase fiber, increase rumination time)
CO2 and Methane are the primary gases given off during rumen fermentation

11. Digestion and Utilization of Prot, CHO and Fats

15. FUNCTION OF FEEDS
Maintenance- a ration which is adequate to prevent any loss or gain of tissue in the body when there is no production
the difference in energy needs are related to the amount of activity
Growth- increase in size of muscles, bones, internal and external parts of the body (the foundation of animal production)
Finishing- the laying on or deposition of fat
Production – lactation, conception, etc.

16. FEEDS
Definition- any ingredients or material fed to animals for purposes of sustaining them
Classes of Feeds
roughages
concentrates
by-products
protein supplements
minerals, vitamins, and additives

17. Classes of Feeds-Roughages
Definition: >18% fiber and lower in energy & low digestibility compared to concentrates
Generally; TDN=40-60% and is high in Ca & K
Forage/Pasture, hay, crop-residue (corn, milo), silage (fermented, high-moisture forage), haylage (low-moisture type silage), green chop

18. Classes of Feeds cont.
Concentrates- high in energy, low in fiber and < 20% protein – Corn, milo, oats, etc.
By-product feeds (from plant and animal processing) carrots, turnip tops, fodder beets
Protein supplements- high in nitrogen
Oilseed Plant by-products (SBM, CSM)

19. Classes of Feeds cont. NPN= non-protein nitrogen
urea, ammoniated molasses or chloride, biruet, etc
Urea=45% Nitrogen X 6.25 = 281% protein equivalent
Minerals - NaCl, limestone, dical, etc.
major -Ca, P, Mg, S
trace - Cu, Fe, I, Mn, Zn, Se, etc.

20. Classes of Feeds Vitamins Special Feeds Natural versus synthetics
water vs fat soluble classification
A,D,& E are most common in ruminants
Special Feeds
Fats and oils (increase calories without bulk)
molasses (increase energy and palatability)

21. Classes of Feeds Feed additives and implants
increase efficiency of gain, prevent diseases, preserve the feed
antibiotics, hormones, growth promotants, repartitioning agents, etc.

22. Evaluation of Feedstuffs
Measuring Energy
TDN= sum total of the digestible protein, fiber, and nitrogen free extract, and fat X 2.25
40% is low for forages while 60% is high
Most concentrates are 80-90%

23. Calorie or California Net Energy System
Net Energy= gross energy-fecal energy-gaseous energy-urinary energy-heat increment
gross energy = combustion heat
digestible energy = portion of gross energy that is not excreted in feces
Metabolic energy = portion of gross energy that is not lost in feces, urine and gas
heat increment = difference between ME & NE
heat unavoidably produced by an animal in digestion and metabolism

24. Evaluation of Feedstuffs
Analyzing Feedstuffs
Proximate analysis
1) H2O (DM vs As Fed),
2)CP 3) Ash 4) Fat
Fiber (ADF, NDF)
Energy (Net or TDN) – bomb calorimeter
Minerals & Vitamins

25. Ration Formulation Consideration points
availability and cost of feedstuffs
moisture content
composition of feedstuffs
soil analysis
nutrient allowances and requirements
composition of ration and ingredients

26. Beef Cow Nutrition Objective
feed little as possible as long as we don’t damage reproduction, milk, or longevity
overfeeding causes decreased longevity, dystocia, reprod. rate, and milk prod.
underfeeding causes delayed estrus, puberty, lowers conception rate and milk prod.

27. Phase Feeding for the Beef Female
feeding accounts for approx. 2/3 of total costs after real estate acquisition
feeding has the greatest influence on growth and performance
Yet, reproduction is the most important economic important trait
feeding influences growth, reproduction (most critical), lactation, etc.

28. Phases of Feeding Birth to weaning Weaning to first breeding
First breeding to first calving
First two productive years (1st two calves)
Third and subsequent years of production

29. Phase Feeding
Plane of nutrition is dependent upon energy and protein requirements along with forage quality and availability
Can be somewhat breed dependent
European cattle are later maturing and will utilize more forage

30. Phase Feeding First phase- Birth to Weaning
objective is to develop replacement females to weaning with maximum subsequent productivity at minimum costs

31. Phase Feeding
Growthier females at weaning will usually reach puberty earlier, calve on time and return to rebreeding earlier than slower growing heifers
Weaning is usually around 205 days or 7 months of age

32. Phase Feeding Second phase - Weaning to First Breeding
objective is to promote adequate growth to insure sexual maturity
first breeding should be done at % of the estimated mature weight
ADG of lbs. per day is recommended

33. Phase Feeding Third phase - First Breeding to First Calving
objective is to promote sufficient growth and body development to allow heifers to deliver a calf, and to prepare the heifers physiologically to be able to withstand the rigors of first lactation and rebreeding.

34. Phase Feeding
Females should gain 70-75% of their weaning weight or be 70-75% of their mature weight at their first calving time.

35. Phase Feeding Fourth phase - First two productive years
Objective is to provide a sufficient plane of nutrition to allow the young cows to lactate, rebreed and continue to grow
cows should not lose more than 15% of their weight during the winter

36. Phase Feeding Fifth phase - Third and subsequent productive years
Objective is to maintain efficient productivity
nutrient requirements actually decrease
Should not lose more than 20% during the winter

37. Feeding in General Obesity can be a major problem
Body Condition Scores should be utilized
Scores of 1-9, where 1 is very thin and 9 is obese : Handout
This can be breed, feed or frame size dependent

38. Feeding in General Heifers - breed more than needed
breed 30 days before the mature cows
palpate 60 days after breeding season
Cows > 10 years of age; the physical condition will diminish
Bulls - during intense breeding season; requirements may increase by 2-3 X
If forage is limiting, feed bulls separate

39. Feeding Systems Creep feeding-
the supplemental feeding of young nursing animals in an enclosure which is accessible to them but not to their parent
gains for young animals are cheap gains due to less fat content in young animals and less consumption/body wt.
adv.- increases weaning wt., facilitates fall calving, uniformity, achieve genetic potential, assists first calf heifers, etc.

40. Creep feeding- is it feasible?
whenever it is most likely profitable
usually when forage or milk is limited
conditions we see in drought that results in overgrazing by mother, thus forage is limited
young cows or very old cows
To be feasible, value difference of the calf should be over the cost of the creep feed
Over creep feeding can cause reduced subsequent milk production because of excessive fat in udders

41. Feeding and Management of Brood Cows
critical time of nutrition
30 days before calving
70 days after calving
growth of calf
reproduction efficiency of cow
Lactation
Rebreeding

42. Feeding and Management of Brood Cows
feed the herd according to cow reproductive pattern
dependant upon:
dry pregnancy
lactating
replacement heifers

43. Feeding and Management of Brood Cows
heifers – the last 3-4 months before parturition is important
weight makes a difference
provide for maintenance and growth
BCS

44. Feeding and Management of Brood Cows
Reproduction and Nutrition
energy is more important than protein
P supplementation increases % calf crop
increase Vit A
level of feed before and after calving
pregnant cows should not gain over 100 lbs during gestation

45. Feeding and Management of Brood Cows
Winter Feeding
grass decreases in protein
must either drylot or supplement
energy is important and should be increased by 10% for every 10 degrees below 20 degrees F
Range Feeding Deficiencies
energy- lack of feed
protein - mature grasses
minerals - lowered salt and P/ vit. - A & ? D, E

46. Feeds for supplementation
Oilseed meals
Grain
Breeder/range cubes
Protein blocks
Liquid feeds (protein or protein/energy)
Syrup blocks or tubs
Hays

47. Supplementation when supplementing; need to know 4 things:
nutrient composition
availability
Intake
requirements

48. Supplementation questions
how much to feed and still make max use
what kind
what form
how often
additives
Alternatives

49. Factors affecting supplementation
Forage quality
Forage quantity and availability
Body condition score
Body size
Milking level
Age

50. Feeding of Bulls age and condition / exercise
increase bulk, decrease grain ( do not want them too fat)
feed young bulls more for growth and development- overfeeding results reduced sperm counts, unsoundness, etc.
mature bulls- increase lbs of grain plus roughage as needed to fit BCS

51. Bulls cont. Young bulls Feed a 12-14% CP ration at 1.5-2% of CWT
Make sure they have plenty of free choice forage
Thumb rule is to feed a 14% CP ration until 14 months of age

52. Pastures two kinds- native and improved
range covers > 40% of the world land area
grasses, browse (woody stem perennial), forbs (hollow stem annual)-weeds
cattle prefer grasses, deer prefer browse
thumb rule- graze 1/2 in summer and save 1/2 for the winter

53. Forages Forage intake vs digestibility Factors that influence intake
body size
forage availability- biggest problem we face
forage palatability
gut fill
rate of passage

54. Forage intake higher the Quality forage, higher intake early maturity
lower proportion of cell walls
higher protein
increased rate of passage
digestibility increases
lowers gut fill

55. Forages Rate of passage or digestion depends on: plant species
plant maturity- more mature, less digestible
cell walls=cellulose vs
cell contents=sugars

56. Forages maturity increases, cell content decreases
protein content> 6% for optimum digestion
preparation method - pelleting, grinding, etc

57. Characteristics of grasses on native range
slower growth rate- reduces quality
longer period to reach maturity
slower re-growth

58. Proper utilization of range
maintain grazing distribution through:
fencing water
shade burning
mowing or spraying
fertilizer
supplemental feeding

59. Improved pastures Don’t graze in early fall or late summer
bermuda grass- adaptable
hybrids- *coastal, Tifton 85, common
good response to N and water
problems- requires cross fencing & N

60. Proper Management
graze when 6-8”, fertilize NPK early spring and N in summer and late summer
can overseed with fescue, wheat, rye in the fall for winter pasture
an increase in N does not necessarily increase performance
yet, it increases quantity, thus stocking rate

61. Thumb Rules
when a cow consumes enough energy, she usually consumes enough protein
Winter- cow should consume 1.5% of body wt with poor forage
2.0% with good quality hay
2.5% with excellent forage such as alfalfa or wheat

62. NPN- non-protein nitrogen
Urea is most popular; other ammonium chloride, biuret, etc.
most effective with high CHO source diet and low protein requirement, twice daily feeding, bacteria in the rumen require energy
not as well utilized at > 12 % protein or in young growing calves or creep