Animal Science 10/23

Key Concepts of EPDs (Expected Progeny Differences)

  • Fat EPD

    • Predictive abilities of Fat EPD

    • Associated with yield grade of the carcass.

    • Relation between ribeye area, fat, and marbling (IMF).

    • Recognized importance of components in yield grade formula:

    • Ribeye area

    • Amount of external fat

    • Internal fat contribution (KPH)

    • Carcass weight

  • Milk EPD

    • Actual function: predicting weaning weights rather than direct milk production.

    • Clarifying that milk is not a direct output measure from the EPD.

Class Structure and Important Dates

  • Reference to upcoming class lectures and the next test scheduled after several lectures.

  • Discussion about the final exam's date, with hints of ongoing uncertainty about specific dates.

Heifer Classifications and Definitions

  • Terminology Sequence

    • Heifer calf

    • Replacement heifer

    • Yearling heifer

    • Bred heifer

    • First calf heifer

    • Mature cow

  • Definitions

    • Replacement Heifer: Young heifer planned for breeding to replace older, culling cows.

    • Bred Heifer: Heifer that is pregnant but hasn't calved yet.

    • First Calf Heifer: Has calved once but is still considered a heifer.

    • Cow: Fully mature female that has had more than two calves.

Dairy Cattle Production Timeline

  • Typical calf weaning age: 6-8 months (average 7).

  • Weight of weaned calves may vary:

    • Typical weight: 400-600 lbs (average around 500).

  • Puberty in cattle typically occurs at 12-14 months of age.

  • Brahmin cattle maturity and breeding dynamics, noting slower maturing compared to other breeds.

  • Breeding Management

    • Importance of managing first-calf breeding for profitability, preferring progeny to arrive before the two-year benchmark.

Economic Viability and Long-term Investment in Cattle

  • First-calf heifers represent significant economic investment.

  • Challenges with deferred income tied to the multiple years before profit realization from replacement heifers.

Lifespan and Longevity of Cattle

  • Average productive lifespan for typical cow breeds: 7-8 years, while Brahmin and Brahmin-influenced cattle can reach longer productive ages up to 20 years.

  • Comparison of productive life and calving intervals, ideally aiming to produce calves annually.

Dairy Cow Production and Statistics

  • Overview of the U.S. dairy industry with key statistics:

    • Leading dairy-producing states: California, Wisconsin, Idaho, New York, Texas, and others.

    • Total dairy cow statistics: About 9.5 million dairy cows producing around 226 billion gallons of milk annually, with approximately 30,000 dairies in the country.

    • Average dairy herd size: 115 cows vs. beef cattle's average herd size of approximately 40.

Trends in Dairy Farming

  • The shift towards larger dairy operations observed from 1997 to 2022.

    • Significant decline in small-scale dairies (< 100 head).

    • Rise in large dairies (> 1,000 head) which now operate the majority of the industry.

  • Concerns surrounding consolidation in dairy farming and risks to milk supply from reduced diversity in dairy operation models.

Challenges in Dairy Farming

  • Efficiency and effective management as keys to success in the dairy industry, particularly with financial margins being tight.

  • Financial viability tied to large-scale production allows for economies of scale, particularly in feed procurement and resource management, providing competitive advantages.

Lactation and Milk Production Information

  • Average dairy cow exhibits a daily production capacity of 6-7 gallons of milk.

  • Peak lactation observed around 60 days after calving.

Hormonal Treatments in Dairy Cattle

  • Introduction of bovine somatotropin (BST) and its implications for increasing milk production.

  • Public resistance to hormone-treated dairy products despite the potential economic advantages.

AI (Artificial Insemination) in Dairy Cattle

  • Prevalence of artificial insemination in dairy cattle farming, with nearly 100% of dairy operations utilizing this method over natural breeding.

    • Comparison to beef cattle, wherein only about 5% utilize AI.

Calf Management in Dairy

  • Dairy calves weaned as early as one day old, reflecting the structure of dairy operations focused on milk production over meat.

  • Presentation of male calves and their typical market use, generally as low-value animals unless they are raised on beef farm.

Heifer and Cow Management Differentiation

  • Distinction in terminology and management strategies between beef and dairy heifers and cows, focusing on nutritional differentiation impacting growth and production.

  • Definitions of terms used in dairy management compared to beef terminology with emphasis on lactation cycles.

Dairy Fertility and Culling Rates

  • Average culling rates for dairy herds highlighting fertility issues with high percentages of cows culled yearly.

  • Reference to management strategies to ensure proper breeding and health of dairy herds, particularly in confinement settings.

Environmental Considerations in Dairy Production

  • Necessities of maintaining a well-managed environment to combat disease and promote the health of dairy cattle in confinement conditions.

  • Challenges of maintaining cow health due to environmental pressures in regions with humidity and rain, leading to limited dairy operations in certain climates.

Conclusion and Final Points

  • Recap of the significance of understanding the dairy industry's structure, statistics, and trends to prepare for related assessments and practical applications.

  • The mixture of economic, management, and genetic selection aspects should be emphasized in preparation for future tests and industry engagements.