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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 - PowerPoint PPT Presentation
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Regulation of Feed Intake in Transition Cows
Barry Bradford
Associate ProfessorKansas State University
135 Call Hall, Manhattan, KS [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 X energy density• Management• Carbohydrate profile• Bioactive nutrients
• Nutrient profile
• 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
Hepatic Oxidation Theory (HOT)
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
HOT Diet
Maximal milk yield
Satiety
Peak lactation cow
COLD DietMilk yield constrainedby nutrient supply
Satiety
Peak lactation cow
What about the transition cow?
Fat mobilization
Triglycerides (TG)
Oxidized orStored as TG
Fatty Acids(NEFA)
OxidizedMilk Fat TG
Liver Muscle
Adipocytes
Mammary
lipolysis, lipogenesis
Depressed feed intake during the transition period
hepatic oxidation
feed intake
plasma glucose
plasma insulin
NEFA
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
-30 -20 -10 00
200
400
600
800
1000
1200
1400
1600
1800
Plas
ma
NEF
A (µ
M)
SEM = 82
Parity: P = 0.02
0 5 10 15 20 25
Control heifers
EN heifers
Control cows
EN cows
SEM = 216
Trt x time x parity:P = 0.09
Day relative to calving
Morey et al., 2011
-25 -20 -15 -10 -5 00
2
4
6
8
10
12
14
16
18
Dry
matt
er in
take
(kg
/ d)
SEM = 1.4
Trt x time x parity:P = 0.07
Niacin did not increase DMI
0 5 10 15 20 25
Control heifers
EN heifers
Control cows
EN cows
SEM = 1.7
Parity: P < 0.01Time: P < 0.01
Day relative to calving
Morey et al., 2011
Niacin has NEFA-independent effects
Titgemeyer et al., 2011
lipolysis, lipogenesis
Depressed feed intake during the transition period
hepatic oxidation
feed intake
plasma glucose
plasma insulin
NEFA
+ Propionate
- Propionate
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 1 – 21 DIM 22 – 91 DIM Low (LL) 21% Starch 21% Starch Medium/High (MH) 23% Starch 26% Starch High (HH) 26% Starch 26% Starch
Nelson et al., 2011
High starch diet limited DMI
1517192123252729
0 5 10 15
DM
I, kg
/d
Week Relative to Parturition
LLMHHH
Trt: P = 0.06Time: P < 0.001Trt x Time: P = 0.09LL > HH: P ≤ 0.10
Nelson et al., 2011
Courtesy of H. M. Dann
n = 78 (total)
202530354045505560
0 5 10 15
Milk
, kg/
d
Week Relative to Parturition
LLMHHH
…and milk yield
Nelson et al., 2011
Courtesy of H. M. Dann
Trt: P = 0.04Time: P < 0.001Trt x Time: P = 0.75MH > HH: P ≤ 0.05
n = 78 (total)
Moderate starch delayed NEFA normalization
Nelson et al., 2011
Courtesy of H. M. Dann
n = 78 (total)
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
DMI, kg/d ECM, kg/d0
5
10
15
20
25
30
35
40
Control5% Sucrose
P = 0.04
P = 0.09
Penner and Oba, 2009
Over the first28 days in milk
n = 52 (total)
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?
Weiss and Pinos-Rodriguez, 2009
n = 72 (total)
Fat in peak lactation?
Weiss and Pinos-Rodriguez, 2009
n = 72 (total)
Fat in peak lactation?
Weiss and Pinos-Rodriguez, 2009
n = 72 (total)
Fat in peak lactation?
Weiss and Pinos-Rodriguez, 2009
n = 72 (total)
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!