Anusorn Cherdthong, PhD Applied Biochemistry in Nutritional Science E-learning: Metabolic Disorders in Animal Nutrition

Introduction Mammary gland structure

Milk composition  85% water  Lactose  Vitamin  Minerals  Protein: casein, whey protein  Fat

Milk composition (%) AnimalWaterFatProteinLactose Cow Goat Swine Human

McDonald et al. (2011) Milk synthesis and substrates

Milk synthesis  Lactose synthesis  Protein synthesis  FA synthesis

Lactose synthesis McDonald et al. (2011)

Lactose synthesis McDonald et al. (2011)

Protein synthesis  Milk---casein and few of  - lactalbumin,  -lactoglobulin  Occurred in endoplasmic reticulum and rough endoplasmic reticulum (RER)  Substrates are AA: diet and microbial protein  Protein product was storaged in golgi  Mechanism protein synthesis similar to other organs

FA synthesis  Occurred at smooth endoplasmic reticulum (SER)  triacylglyceride is major product  Storage in alveolus  FA received from:  Diet: intake, synthesis from C2, C4  Mobilization from adipose tissue

Milk synthesis control Brisken and O'Malley (2010)

Conclusion 1 2 Protein synthesis from diet and microbes Lactose synthesis with 7 steps 3 FA synthesis as triacylglycerol by use VFA, diet as substrate

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