Dairy Cattle Nutrition: The Basics

Presented by Dr. L. E. Chase, Cornell University

Overview of Today's Dairy Cow

• Dairy cows are highly efficient biological manufacturing plants.
• Milk Production:
  • Average New York dairy cow milk production increased from 10,885 lbs (1970) to 20,071 lbs (2009), marking an 84% increase.
  • Some herds in NY exceed 30,000 lbs/cow in milk production.
• Biological limits to milk production are explored.

Notable Records

• Holstein World Record: Ever-Green-View My 1326-ET with 72,170 lbs of milk in 365 days, averaging 198 lbs/day.
• Jersey World Record: 49,250 lbs of milk with 4.6% fat and 3.3% true protein content.
• Lifetime Milk Production Record: 442,690 lbs of milk.

Nutrition and Excretion

• Excretion by Cows Producing 100 lbs of Milk/Day:
  • 13 lbs of dry matter, lactose, milk fat, and protein.
  • 70 lbs of total manure including urine and fecal material.
• Nutritional Needs:
  • Glucose: 7-8 lbs
  • Microbial protein: 3-4 lbs
  • Absorbed amino acids: 2-2.5 lbs
• Feed and Water Intake:
  • 55-60 lbs of dry matter, 130 lbs of wet feed.
  • Water intake: 30-35 gallons.

Importance of Dry Matter Intake (DMI)

• DMI should align with cow's consumption capacity.
• Essential for potential milk production, costs, and profitability.
• Rations are nutrient density-based; DMI is critical for problem-solving.

Influences on DMI

• Factors Affecting DMI:
  • Cow-specific: milk production, genetics, health status.
  • Environmental: air quality, temperature, humidity.
  • Forage quality and condition.
  • Concentrate quality and compatibility with forage.

Monitoring DMI and Feed Management

• Use scales and moisture testers to measure feed intake accurately.
• Calculate and compare actual versus predicted grain disappearance.

Nutritional Requirements for Cows

• Basic Nutrients: Water, protein, carbohydrates, lipids/fats, minerals, vitamins, energy.
• Water is the most required nutrient.
• Nutrient Analysis:
  • Fiber vs. ADF (Acid Detergent Fiber).
  • Ruminants have simpler requirements due to microbial synthesis in the rumen.

Energy and Nutritional Efficiency

• Energy obtained from carbohydrates, fats, and proteins.
• Protein is crucial for body tissues and enhances feed intake.
  • Rumen degradable protein (RDP) vs. Undegradable protein (RUP).
  • Microbial protein provides about 50% of the cow's protein needs.

Carbohydrates and Fiber

• Major energy source; broken down into VFAs and gases.
• Structural vs. Nonstructural carbohydrates impact digestion speed.
• Fiber Recommendations: Chemical NDF, fermentability, and physical NDF considerations.

Fats and Minerals

• Fats: High energy, supports diet, but excessive fat inhibits rumen digestion.
• Minerals: Essential for milk production (e.g., calcium).
• Both macro and micro minerals are crucial.

Vitamins

• Water-Soluble: Mostly self-produced by rumen bugs; exceptions may include niacin supplementation.
• Fat-Soluble: A, D, E, and K; often supplemented due to high milk production demands.

Summary

• The presentation highlighted essential aspects of dairy cattle nutrition, emphasizing the importance of understanding feed intake, nutritional needs, and efficient feed management to optimize milk production and dairy farm profitability.