Milk Fatty Acids: The Building Blocks of Fat

Transcription

1 Milk Fatty Acids: The Building Blocks of Fat Lawrence R. Jones, PhD American Farm Products, Inc FARME Institute, Inc The mammary cell has evolved to provide nourishment for the calf 2 1

2 Milk fat is encased in membrane to ensure it passes to the small intestine 3 Most fat in milk is in the form of triglycerides 4 2

3 The mammary cell is a very big place. How do FA come together? 5 C14 C16 C8 The mammary cell is a very big place. How do FA come together? 6 3

4 MS ID#: JBC/2017/ Title: Acute Acinar Pancreatitis Blocks Vesicle Associated Membrane Protein 8 (VAMP8) Dependent Secretion Resulting in Intracellular Trypsin Accumulation Elaina K. Jones, PhD Candidate University of Wisconsin FARME Institute Board member Fatty acid trafficking is poorly understood There may be a hormone component to this 7 There are a small number of triglycerol molecules that make up milk fat 8 4

5 sn 1 sn 2 sn % of 18:0 59.3% of 18:1 44.4% of 16:0 43.5% of 8:0 51.4% of 10:0 59.8% of 12:0 62.2% of 14:0 43.1% of 16:0 98.1% of 4:0 93.2% of 6:0 52.5% of 8:0 27.8% of 18:0 41.3% of 18:1 The distribution of FA on the triglyceride are not random 9 Chain Length sn1 sn2 Sn % C4 C % C % C18 In this case, if you add more C18, do you expect more milk fat? 10 5

6 Chain Length sn1 sn2 sn Additional C18, limited C4 C16 26% C4 C14 35% C16 39% C18 Less C16, more C4 C14 11 Chain Length sn1 sn2 sn The cell does not make random triglycerides! 12 6

7 CVAS Milk Fatty Acid Graph What are the sources of milk fatty acids? 13 Rumen VFAs Acetate Butyrate Fatty Acid Synthetase Acetyl CoA Carboxylase C4 C6 C8 C10 C12 C14 C16 De novo made in the mammary gland 14 7

8 Diet and body fat C16:0 C18:0 C16 C18:0 C18:1 Delta 9 desaturase Preformed made outside mammary gland 15 Rumen VFAs Acetate Butyrate Diet C16:0 Fatty Acid Synthetase Acetyl CoA Carboxylase C16 Mixed C16 both de novo and preformed 16 8

9 C18:2 trans 10 cis 12 Rumen VFAs Acetate Butyrate Fatty Acid Synthetase Acetyl CoA Carboxylase C4 C6 X C8 X C10 X C12 X C14 X C16 X Chain Length sn1 sn2 Sn X X X X X X X X X Classical Milk Fat Depression 17 C18:2 trans 10 cis 12 Rumen VFAs Acetate Butyrate Fatty Acid Synthetase Acetyl CoA Carboxylase C4 C6 X C8 X C10 X C12 X C14 X C16 X Chain Length sn1 sn2 Sn X X X X X X X X X Classical Milk Fat Depression This will not respond to supplemental fat (c16 or C18) 18 9

10 Fat Lactose Protein De Novo Mixed Preformed De Novo Mixed Preformed Milk g/100 g milk g/100 g FA # carbons dbl/fa Bulk Tank Milk Fatty Acid Analysis 19 dbl/fa DBL/FA DB/FA % Preformed Double Bonds per FA is a function of % Preformed 90% of C18:1 cis 9 is made by the mammary gland 20 10

11 # carbons Chain length carbon # % Preformed (% FA) Chain length is a function of % Preformed FA 21 De Novo Mixed Preformed g/100 g FA Fatty acids as a percent of fatty acids A + B + C = 100%, If A increases, C must decrease 22 11

12 Fat Lactose Protein De Novo Mixed Preformed Milk g/100 g milk Core Bulk Tank Milk Fatty Acid Analysis 23 Fat Protein de novo Mixed Preformed Average Expected based on fat Goal C18:2 trans 10 cis 12 Rumen VFAs Acetate Butyrate Fatty Acid Synthetase Acetyl CoA Carboxylase C4 C6 X C8 X C10 X C12 X C14 X C16 X Low fat, normal protein CLA induced MFD, no rumen effect 24 12

13 %(m/m) %(m/m) %(m/m) Denovo Mixed Preformed Fat D Lactose Protein g/100 g g/100 g g/100 g Benchmarks Supplemental C16 will reduce C16 made de novo, thereby increasing the C4 C14 fatty acids. High fat compared to protein, high C16 High Palm Fat 25 % Protein % Fat % de Novo % Mixed % Preformed Mean Reference % Protein de novo (g/100 g milk) Low fat and low protein, CLA not suspected Need more acetate and butyrate from the rumen 26 13

14 Denovo Mixed Preformed Fat Protein g/100 g Mean Goal Mammary cells need more long chain fatty acids for higher milkfat. These need to be supplemented or spared! Low fat, normal protein, low preformed Competition between liver and mammary gland for energy 27 Severe milk fat depression is usually caused by toxic trans fatty acids inhibiting de novo fatty acid synthesis Mild milk fat depression with equally depressed protein is usually a poor rumen fermentation. Fatty Acids are the building blocks of milk fat Cause #1 Poor de novo synthesis 28 14

15 Adding Palm Fat (C16) will usually reduce de novo synthesis of C16. Acetate and butyrate will be spared to build more C4 C14 Feeding Palm Fat often masks poor rumen fermentation. Protein usually does not respond. IOFC usually goes down. Fatty Acids are the building blocks of milk fat High Palm Fat supplementation can artificially support milk fat 29 Preformed fatty acids are low when long chain fatty acids are used elsewhere. Or not supplied. Preformed fatty acids will be high when cows are losing weight. Fatty Acids are the building blocks of milk fat Low Preformed Fatty acids are caused by a low energy status 30 15

16 Milk Fatty Acids: The Building Blocks of Fat Lawrence R. Jones, PhD American Farm Products, Inc FARME Institute, Inc 16