Animal Breeding and Reproduction in Livestock

These flashcards cover key concepts related to animal breeding, genetics, and reproduction in livestock, extracted from the lecture notes.

What is animal breeding?

Animal breeding is the practice of selectively mating livestock to increase desirable traits in future generations.

Why is animal breeding more important now than it was 50 years ago?

Animal breeding is more important now due to advancements in biotechnology and genetic research, leading to improved productivity and health in livestock.

Have all species of livestock benefited from animal breeding research? Why or why not?

No, not all species have benefited equally; some have undergone more extensive research and development than others, depending on economic demand and scientific focus.

What is heritability?

Heritability is the proportion of observed variation in a trait that can be attributed to inherited genetic factors.

Describe the difference in heritability among growth traits, reproductive traits, and carcass traits in beef cattle.

Growth traits are generally more heritable than reproductive traits, while carcass traits vary but can also show significant heritability.

Why is understanding genetic correlations important in beef cattle breeding?

Understanding genetic correlations helps breeders make informed decisions about which traits to select, avoiding negative impacts on desirable characteristics.

What is an EPD?

An Expected Progeny Difference (EPD) is a prediction of future performance of offspring based on their genetic potential.

What traits can EPDs be calculated for?

EPDs can be calculated for a variety of traits, including growth rates, reproductive performance, and carcass quality attributes.

What is a contemporary group?

A contemporary group consists of animals raised under similar conditions, allowing for more accurate comparisons of performance.

What does it mean for EPDs within a breed to be standardized?

Standardization of EPDs ensures that they are comparable across different herds and environments, providing uniform evaluation.

What is a maternal effect in beef cattle?

A maternal effect is an influence a dam has on the phenotype of her offspring based on her own genetics and environment.

Describe the differences in the use of EPDs between seedstock and commercial herds.

Seedstock producers use EPDs to select breeding stock for genetic advancement, whereas commercial herds use them primarily for market traits.

What are the challenges in calculating across-breed EPDs?

Challenges include differences in breed genetics, management practices, and database standards which affect the reliability of comparisons.

What is lactation?

Lactation is the process of producing and secreting milk from the mammary glands of female mammals.

What is mastitis, and why is it a problem?

Mastitis is an infection of the mammary gland that can lead to decreased milk production and quality, posing economic challenges.

What does the term 'genetic correlations are seldom perfect' mean?

It refers to the idea that while two traits may be related genetically, they do not always respond uniformly to selection.

What is the economic value of the swine industry to U.S. agriculture?

The swine industry significantly contributes to U.S. agriculture through meat production, job creation, and resource utilization.

Describe the importance of biosecurity in livestock breeding.

Biosecurity is crucial in preventing disease spread, protecting herd health, and ensuring the success of breeding programs.