Feeding for milk composition
1 / 31


  • Updated On :

FEEDING FOR MILK COMPOSITION. José Eduardo Portela Santos VMTRC – UC Davis. Milk Components. Fat Content Fatty acid profile Crude protein Content True protein vs NPN Lactose Minerals and vitamins. Several nutritional factors affect the composition of milk of dairy cows:

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'FEEDING FOR MILK COMPOSITION' - tricia

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Feeding for milk composition l.jpg


José Eduardo Portela Santos

VMTRC – UC Davis

Milk components l.jpg
Milk Components

  • Fat

    • Content

    • Fatty acid profile

  • Crude protein

    • Content

    • True protein vs NPN

  • Lactose

  • Minerals and vitamins

Slide3 l.jpg

  • Several nutritional factors affect the composition of milk of dairy cows:

    • Energy intake (Mcal of NEL)

    • Energy source

      • CHO

      • Lipids

    • Protein intake

    • Protein degradability and quality

    • Interactions between protein and energy

    • Amino acids

    • Minerals: Na, K (DCAD)

    • Feed additives (Niacin, fibrolytic enzymes)

Milk fat l.jpg
Milk Fat of dairy cows:

  • Forage:Concentrate ratio

  • CHO:

    • NDF

    • Effective NDF

    • Physically effective NDF

    • Ruminal digestibility of NDF

    • NFC

      • Composition of the NFC: sugars, starch and pectin

      • Ruminal degradability of starch

Slide5 l.jpg

  • Ionophores of dairy cows:

  • Fat supplementation

  • Lack of RDP (fiber digestibility and buffering effect)

  • Dietary buffers

Theories l.jpg
Theories of dairy cows:

  • Low fat diets

  • Acetate deficiency

  • B-OH-butyrate deficiency

  • High rumen molar concentration of propionate: Insulin theory (glucogenic theory)

  • Vit. B12 deficiency

  • Trans fatty acids

Mechanism of action of trans fa l.jpg
Mechanism of Action of of dairy cows:Trans FA

  • Milk fat suppression: reduced SCFA (De Novo synthesis)

  • Trans fatty acids depress milk fat in 48 to 72 hs

  • Preliminary data from Maryland (Piperova et al., 1998):

    • Acetil CoA Carboxylase activity decreased (61%)

    • Fatty acid synthase activity decreased (54%)

    • Acetil CoA Carboxylase mRNA decreased (55%)

Nutritional causes of milk fat suppression l.jpg
Nutritional Causes of Milk Fat Suppression of dairy cows:

  • Inadequate NDF

  • Inadequate physically effective NDF (particle size)

  • Poor NDF digestibility

  • Forage source: buffering capacity

  • Excessive amounts of NFC

  • Excessive amounts of RDS

  • High fat diets

Slide13 l.jpg

  • Fat sources with highly unsaturated FA profile of dairy cows:

    • Yellow grease, oils

  • Interactions between fat source and forage source (binding sites)

    • Alfalfa hay vs corn silage

  • Protein supplements with high PUFA content

    • Fish meal, blends of marine by products

  • Lack of RDP (fiber digestibility & buffer effect)

  • Lack of buffers

Milk protein l.jpg
Milk Protein of dairy cows:

  • NEL intake

  • Forage:Concentrate ratio

  • Amount of fermentable CHO (RDS)

  • Dietary CP level

  • Amino acid profile of the protein flowing to the duodenum

  • Dietary fat

Effect of grain processing on plasma insulin l.jpg
Effect of Grain Processing on Plasma Insulin of dairy cows:

P < 0.05

  • Data from 832 blood samples from 32 cows (Santos et al., 2000)

Slide21 l.jpg

Dietary protein and milk protein l.jpg
Dietary Protein and Milk Protein of dairy cows:

  • Low efficiency of N utilization for milk protein synthesis (< 30%)

  • Sprndly (1986): No relationship between dietary CP content and milk protein concentration

  • Emery (1978): correlation between dietary CP and milk protein content (r2=0.35)

    • The effect of higher CP diet is associated with greater DMI and total energy intake

Dietary fat and milk protein l.jpg
Dietary Fat and Milk Protein of dairy cows:

  • Negative relationship between dietary fat and milk protein concentration

  • Independent of fat source

  • Increased efficiency of amino acid extraction

  • Supplying more fermentable CHO or high quality RUP partially overcomes milk protein depression

Conclusions l.jpg
Conclusions of dairy cows: