This document discusses how dietary factors affect the composition of milk in dairy cows. It explains that the nutrients cows consume are fermented in the rumen by microbes, and the fermentation products then determine the fat, protein, and lactose content of the milk. High-starch diets decrease milk fat by reducing levels of acetic and butyric acids. Milk protein can be increased by raising the protein content and bypass protein levels in cow feed, using ingredients like protected soybean meal. Maintaining proper nutrition and balancing rations is important for optimal milk composition.

1. Dietary Factors Affecting Milk
Quality in Dairy Cows
Dr. Pankaj Kumar Singh
Department of Animal Nutrition
Bihar Animal Sciences University, Patna, India
E-mail: vetpank@gmail.com

2. Composition of Milk

3. Nutrient flow from the rumen and milk components

4. Nutrients and milk composition
• Nutrition has an impact on milk composition.
• Cow ferment the ration in the rumen with the help of
microbes.
• The different fermentation products determine the
composition of the milk
– Milk fat
– Milk protein,
– Milk lactose

5. Milk Fat
• The milk fat content is determined by the acetic and
butyric acid production from rumen fermentation.
• Diets with a high starch content reduce the absolute and
relative concentrations of the milk fat.
• Milk fat content influenced by the feedstuffs
– Fiber
– Carbohydrates (Cotton Seed cake, Jute seed cake etc.)
– Fats

6. Milk Lactose
• Propionic acid is precursor the milk lactose content.
• The content of lactose in the milk is nearly stable
• Even when a ration deficient in energy is fed, the lactose
content of the milk will remain relatively constant.

7. Milk protein
• Milk protein in milk can best be increased by:
– Increasing the protein content of the ration.
– Increasing the by-pass protein
– Ingredients like protected soybean meal.
– Feeding protected methionine.

9. Plane of Nutrition
• Under feeding & Feeding imbalanced
ration:
–Reduced Fat %
–Reduced Lactose %

10. Level of Starch in the Ration
Level of Starch in ration Increases:
• Level of propionate increases in the rumen
• Level of Acetate decreases in the rumen
• Reduction in Fat percent

11. Milk Fat

13. Thank
You