Transcript Current Concepts and Recent Advances in Transition Cow

Regulation of Feed Intake in Transition
Cows
Barry Bradford
Associate Professor
Kansas State University
135 Call Hall, Manhattan, KS 66506
[email protected]
1-785-532-7974
Typical Transition Cow Goals
• Avoid transition disorders
• Promote a steady rise in feed intake and milk
production to meet peak lactation goals
• Set the stage for reproductive success
• Key to all of these: Minimize time and degree
of negative energy balance
Promoting energy intake
Energy intake =
dry matter intake
• Management
• Carbohydrate profile
• Bioactive nutrients
X
energy density
• Nutrient profile
Hepatic Oxidation Theory (HOT)
• Liver is “hard-wired” to brain feeding centers via
vagus nerve
• Great variation in pattern of oxidation of fuels over
the short-term
• Feed intake is affected by pattern of oxidation
• Goal: maximize the amount of glucose produced per
unit of ATP generated in the liver over time
What are “hot” and “cold” diets?
• Hot = highly fermentable
– Highly digestible forage sources
– Relatively high concentrate levels
– Some substitution of forage with nonforage fiber
sources (byproducts)
• Cold = less fermentable
– Higher forage concentrations
– Some poorly digestible forage (i.e. straw)
– Resistant starch and/or nonforage fiber replaces some
processed starch
Peak lactation cow
Satiety
Maximal milk yield
HOT Diet
Peak lactation cow
Satiety
COLD Diet
Milk yield constrained
by nutrient supply
What about the transition cow?
Fat mobilization
Triglycerides
(TG)
Fatty Acids
(NEFA)
Adipocytes
Milk Fat TG
Oxidized or
Stored as TG
Oxidized
Mammary
Liver
Muscle
Depressed feed intake during the
transition period
plasma insulin
plasma glucose
lipolysis, lipogenesis
feed intake
NEFA
hepatic oxidation
Can limiting NEFA release preventing
DMI depression?
• Fed 24 g/d rumen-protected niacin
• Close-up ration:
– 35% NFC, 42% NDF, 1.55 Mcal NEL / kg DM
• Fresh cow ration:
– 40% NFC, 32% NDF, 1.69 Mcal NEL / kg DM
• Treatments from 21 days before calving
to 21 DIM
Morey et al., 2011
Encapsulated niacin
decreased plasma NEFA
1800
Control heifers
Plasma NEFA (µM)
1600
EN heifers
1400
1200
Control cows
SEM = 82
1000
800
EN cows
Parity: P = 0.02
600
SEM = 216
400
Trt x time x parity:
P = 0.09
200
0
-30
-20
-10
0
10
20
30
Day relative to calving
Morey et al., 2011
Niacin did not increase DMI
Dry matter intake (kg / d)
18
Control heifers
16
14
EN heifers
12
Control cows
10
EN cows
8
6
SEM = 1.4
SEM = 1.7
Trt x time x parity:
P = 0.07
Parity: P < 0.01
Time: P < 0.01
4
2
0
-30
-20
-10
0
10
20
Day relative to calving
Morey et al., 2011
30
Niacin has NEFA-independent effects
Titgemeyer et al., 2011
Depressed feed intake during the
transition period
plasma insulin
- Propionate
plasma glucose
lipolysis, lipogenesis
feed intake
NEFA
+ Propionate
hepatic oxidation
Propionate has dual effects in early
lactation
• Experimental infusion of propionate for 72
hours in early lactation decreased feed intake
by 10% compared to acetate infusion
• This response was the most dramatic in cows
with high blood NEFA concentrations
Stocks and Allen, 2010, 2011
How much starch in early lactation?
• Diets were based on corn silage (35%) and
alfalfa silage (11.5%) and included 4% wheat
straw
• Corn meal, soy hulls, and wheat midds were
varied
Table 1. Dietary treatments
Low
Medium/High
High
(LL)
(MH)
(HH)
1 – 21 DIM
21% Starch
23% Starch
26% Starch
22 – 91 DIM
21% Starch
26% Starch
26% Starch
Nelson et al., 2011
High starch diet limited DMI
29
DMI, kg/d
27
25
LL
23
MH
Trt: P = 0.06
Time: P < 0.001
Trt x Time: P = 0.09
LL > HH: P ≤ 0.10
21
19
17
HH
15
0
5
10
15
Week Relative to Parturition
Courtesy of H. M. Dann
n = 78 (total)
Nelson et al., 2011
Milk, kg/d
…and milk yield
60
55
50
45
40
35
30
25
20
LL
MH
Trt: P = 0.04
Time: P < 0.001
Trt x Time: P = 0.75
MH > HH: P ≤ 0.05
0
5
10
HH
15
Week Relative to Parturition
Courtesy of H. M. Dann
n = 78 (total)
Nelson et al., 2011
Moderate starch delayed NEFA
normalization
Courtesy of H. M. Dann
n = 78 (total)
Nelson et al., 2011
What about sugar?
• Sucrose was used to replace cracked corn
grain at 4.7% of diet dry matter
• Diets were approximately 34% NDF, 34% NFC
– 20.5 vs. 18.5% starch
– 4.5 vs. 8.7% water-soluble sugars
• Fed for first 28 days in milk
Penner and Oba, 2009
Dietary sucrose increased DMI, ECM
40
35
Over the first
28 days in milk
P = 0.09
30
25
P = 0.04
Control
20
5% Sucrose
15
10
5
0
DMI, kg/d
ECM, kg/d
n = 52 (total)
Penner and Oba, 2009
Dietary sucrose in transition diets
• Sucrose did not alter energy balance
• Sucrose decreased plasma glucose and
increased NEFA and BHBA concentrations
• Increased ruminal pH (6.06 vs. 6.21, P = 0.08)
• Increased total-tract OM digestibility, not NDF
• Increased ruminal NDF digestibility and
passage?
Penner and Oba, 2009
Fat in peak lactation?
• Cows were fed a common diet for first 21 DIM,
then randomly assigned to 1 of 4 diets:
• 60:40 forage:concentrate
– 2.9% fatty acids
– 5.0% fatty acids (prilled hydrogenated fatty acids)
• 40:60 forage:concentrate
– 3.4% fatty acids
– 5.5% fatty acids (prilled hydrogenated fatty acids)
Weiss and Pinos-Rodriguez, 2009
Fat in peak lactation?
n = 72 (total)
Weiss and Pinos-Rodriguez, 2009
Fat in peak lactation?
n = 72 (total)
Weiss and Pinos-Rodriguez, 2009
Fat in peak lactation?
n = 72 (total)
Weiss and Pinos-Rodriguez, 2009
Fat in peak lactation?
n = 72 (total)
Weiss and Pinos-Rodriguez, 2009
Transition diet recommendations
• Goals: Decrease NEFA, maintain rumen fill
• Feed fiber with long ruminal retention time
• Target moderate starch fermentability to
supply adequate propionate without rapid
production in a meal
• Consider using a sugar source (4-5% of DM)
When to change to the peak diet?
• Ideally, change to peak-lactation diet when
plasma NEFA and ketones decrease and intake
is steadily increasing
• Practically, cows with steadily rising feed
intake and milk yield may be ready to shift
diets as early as 7 days in milk, or as late as 21
days in milk
Peak lactation
• Dry matter intake is limited by gut fill in most
cows
• Additional energy in the form of starch or fat
should not depress DMI (within reason)
• Additional energy can increase BOTH milk
production and BCS
Conclusions
• Attempts to prevent negative energy balance
in early lactation haven’t worked!
• More energy in = more milk, in most cases
• There is hope for improved feed intake, which
generally improves transition performance
Thank you!