Transcript Nutritional Considerations for the Cow Herd

Nutritional
Considerations
for the
Cow Herd
(based on calving season)
What do they need?
When do they need it?
Energy
• Result of CHO and Lipid metabolism
(eg. Converting hay to VFA)
• Requires the majority of feed intake
• Most commonly deficient nutrient for
the brood cow
Estimated Net Energy Requirements
for 2-, 3-, and 5-year old Cows
Calving
Breeding Season
2-year old
18
3-year old
16
5-year old
14
Wean
Mcal/d
12
10
8
6
4
2
0
Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept
Months Since Calving
1996 Beef NRC
Protein
• Cattle have 2 protein
requirements
– N needs of rumen bacteria
– Amino acids of the animal
• Degradable Intake Protein (DIP)
– Breakdown in rumen and supply N to
bacteria
• Undegradable Intake Protein (UIP)
– Escape rumen, digested in gut,
supply AA
Protein Needs for Cows
Crude Protein, %
14
12
10
8
6
4
2
0
1
2
3
30 lb peak milk production
4
5
6
7
8
9 10 11 12
Month Since Calving
Macro & Micro Minerals
Macro
• Salt (NaCl)
• Calcium (Ca)
• Phosphorous (P)
• Magnesium (Mg)
• Potassium (K)
• Sulfur (S)
Micro
• Copper (Cu)
• Selenium (Se)
• Zinc (Zn)
• Manganese (Mn)
• Cobalt (Co)
• Iron (Fe)
• Chromium (Cr)
• Molybdenum (Mo)
• Iodine (I)
• Nickel (Ni)
Mineral Content of Forages
• Grasses are low in P, Mg, Se, Cu,
Zn, Mn and others
• Grasses are high in Ca and K
• Grains are low in Ca, K, and
many TM
Vitamins
• Fat Soluble
– A, D, E and K
• Water Soluble
– B complex and C
• For the cow, A is the only vitamin
deficient under normal
circumstances
Water
• Factors affecting water intake
– Temperature
– Feed moisture
– Body size
– Production status
Objective
Meet the nutritional
needs of the cow herd
as economically as
possible….
…generally on fescuebased pasture systems
which minimize the need
for stored (hay, silage) or
purchased (supplements)
feeds.
Critical
Feb. 15
M
Critical
A
M
J
J
A
S
O
N
D
J
Goals
(Spring Calving Cows)
• Feed a least-cost,
balanced ration
• Have healthy,
vigorous calves and a
good milk supply
• Cycle early and
rebreed before
extreme heat (in July)
Requirements of Spring Calving Cows
Fescue Production vs. Spring Calvers
Goals
(Fall Calving Cows)
• Feed a least-cost,
balanced ration
• Rebreed in
December/January
• Extra feed for calves
during February 15 to
April 15 (creep graze
or feed)
Requirements of Fall Calving Cows
Fescue Production vs. Fall Calvers
How do you make
up the deficiency
from pastures?
Allocation of Hay to Various
Classes of Cattle Based on
Quality
Quality of Hay
High
Low
Classes of Cattle
Young Calves
Weaned Calves
Replacements
Yearlings
Bred Heifers
2-year old Cows
Lactating Cows
Mature Cows, last 1/3 of
gestation
• Mature Bulls
• Mature Pregnant Cows,
first 2/3 of gestation
•
•
•
•
•
•
•
•
How much hay
does a cow have to
have daily?
Cow and Calf Performance,
Feed Intake, lbs
Control
Rumensin
Precalving Hay
26.8
23.2
Postcalving Hay
30.5
26.2
3.5
3.0
SBH
Or use your forage analysis
to estimate dry matter
intake…
120 / NDF (%) = DMI (% BW)
Approximate forage intake by
beef cattle
Forage
TDN %
DMI (%BW)
Well-eared silage
60-70
2.5 to 3.3
70
2.0 to 2.5
Legume hay, good
55-60
2.5 to 3.0
Grass hay, good
50-55
2.0 to 2.5
Mature grass hay
45-50
1.5 to 2.0
Grass hay, poor
40-45
1.0 to 1.5
Straw
35-40
1.0 or less
Actively growing pasture
Find out how much hay
the cow will consume
and make up a deficiency
with energy or protein
supplement
Balance the ration
for needed nutrients
Sort Cows and Increase
Feed After Calving
Energy Deficiencies Affect
• Cow Rebreeding
• Calf Health/Survival
• Calf Growth Rate
Timing of Deficiency Influences
Effect
• Pre-calving deficiency  days of
post partum interval
• Post-calving deficiency  %
conception
How do you monitor
the nutrition adequacy
of your feeding
program?
Beef Cattle Body Condition
Scoring
• Reflects adequacy of feeding program
• BCS is a visual assessment of body fat
• Scoring range of 1 to 9, 1=thin,
9=obese
• A score = 4 to 5% empty body fat and
65 to 85 lbs of body weight
Body Condition Score (BCS)
in Beef Cows
• Highly related to reproductive
efficiency
• Calving time BCS very important
• Thin cows at calving have  days
return to heat and  pregnancy rate
Putting it all together
Forage System 1 (Control)
FescueN
Forage System 2 (High)
Fescue-N
Bermuda
grass/
Cereal Grain
Fescue-N
Fescue-N
= creep gate
Fescue/
Clover
Fescue/
Clover
Forage System 3 (Low)
Fescue-N
Bermuda
grass/
Cereal Grain
Fescue-N
Fescue-N
= creep gate
Fescue/
Clover
Fescue/
Clover
Forage System 4 (High)
Fescue-N
Bermuda
grass/
Cereal Grain
Fescue-N
Fescue-N
= creep gate
Fescue/
Clover
Fescue/
Clover
Forage System 5 (High)
Fescue/
Clover
Fescue/
Clover
Fescue/
Clover
Fescue-N
Fescue-N
Fescue-N
= creep feeder (soyhulls)
Performance of cattle on different forage/management
systems (1.6 acres/cow) , 3 years.
Forage Management System
Item
SCH
SRH
SRL
FRH
FRHCr
Wt. @ breeding, lbs
1,320
1,283
1,287
1,326
1,276
Timed A.I. preg. Rate,
%
50.9
60.1
49.7
62.5
71.4
Overall pregnancy
rate, %
82.4
88.8
93.6
88.6
95.3
Calving loss, %
8.9
11.1
6.7
4.4
8.9
Performance of cattle on different forage/management systems
(1.6 acres/cow), 3 years.
Forage Management System
SCH
SRH
SRL
FRH
FRHCr
Birthdate
Mar. 6
Mar. 6
Mar. 11
Sept. 30
Sept. 24
Birth Wt., lb
85.6
89.7
88.1
80.2
79.4
Weaning date
Sept. 6
Oct. 17
Oct. 17
June 1
June 1
ADG, lb
2.30
2.18
2.29
2.16
2.27
Adj. 205 day wt, lb
573.1
555.4
572.2
536.8
560.5
Actual wean wt, lb
575.7
580.3
590.2
608.5
650.3
Creep feed
(soyhulls), lb, hd
-
-
-
-
821
Averages
Differing costs and income per year for different
forage/management systems (15 cows on 24 acres)
Forage Management System
Item
SCH
SRH
SRL
FRH
FRHCr
Income minus
differing cost
$4,963.60
$5,482.83
$5,949.08
$5,474.93
$6,071.60
Advantage over
unimproved
system, $
-
$519.83
$985.48
$511.33
$1,108.00
(Per cow)
-
$34.62
$65.70
$34.09
$73.87
Latest Research
in Mineral Supplementation
Parameter Evaluated Affects Animals
Mineral Requirement
Immunity > Fertility > Growth > Maintenance
Factors influencing mineral intake from
forage
• Forage mineral content
• Forage mineral availability
• Antagonists
• Dry matter intake
Organic vs. Inorganic Minerals
• Absorbed by a different system
• Use in presence of antagonists
• Better at immune stimulation
Situation:
Selenium (a trace mineral) is presently supplied
as sodium selenite at 3X NRC recommended
level, yet deficiencies seem to appear
(impaired immunity, etc.) FDA max. daily
allowable is 3mg/hd/da in supplement
Effect of Dietary Selenium (Se)
Supplementation on Tissue Se Concentration
Item
Control
NaSe
Sel-Plex
P Value
Red Blood Cells,
mg/ml
0.26 (a)
0.34 (b)
0.42 (c)
<.0001
Liver, mg/g
0.26 (a)
0.34 (b)
0.47 (c)
<.0001
Flow chart of experimental approaches and
molecular bio-techniques used
Animal trial
Tissue collection
Liver
Se analysis of blood &
liver tissues
RNA extraction
(By Dr. Mahan’s laboratory)
cDNA  cRNA
Microarray hybridization
Bioinformatic analysis
Genes Altered by Se Supplementation:
Identification of a Common Effect Between Treatments
125 (P < 0.01)
Fisher’s protected LSD (P < 0.05)
26 (13,13)
regulated by ISe
30 (17,13) regulated
dually by
23 (14,9) regulated
by OSe
Implications
• The form of Se supplied in beef cattle mineral mixes
matters!
• Therefore, the consequence of recommending
inorganic or organic forms of Se to be used in
mineral mixes needs to be fully understood from a
physiological, and not just economical, perspective.
0.700
Liver Se (µg/g)
0.600
0.500
0.400
Control
0.300
ISe
Mix
0.200
OSe
0.100
0.000
0
28
56
84
112
140
168
Days on treatment
196
224
Effects of selenium on beef cows
and their calves
Testis
• Male Calf Testicles
– Gestational source of dietary Se affects
neonatal calf testes- affects spermatogenesis,
may affect fertility in males
– Maternal source of Se affect steroidogenic
gene expression. Can affect androgenesis
and estradiol- 17β.
Effects of Se source on blastocyst
development from super ovulated
beef cows
• More High quality embryos with mix