Genetic parameters for linear type traits in the Rendena dual-purpose breed

Area of Science:

• Animal Genetics
• Quantitative Genetics
• Livestock Breeding

Background:

• Rendena cattle are a dual-purpose breed, historically valued for both milk and meat production.
• Understanding genetic parameters is crucial for effective breeding programs in dual-purpose cattle.

Purpose of the Study:

• To estimate genetic parameters for composite and individual type traits in Rendena dual-purpose cows.
• To analyze genetic trends and correlations among these traits.

Main Methods:

• Linear animal mixed models were applied to data from 10,735 first-parity Rendena cows.
• Fixed effects included herd-year-classifier, days in milk, and age at first calving.
• Additive genetic effects were treated as random effects.

Main Results:

• Heritability estimates ranged from 0.12 for feet to 0.52 for stature.
• Strong positive genetic correlations (≥0.69) were found among body size traits and morphological characteristics.
• Negative genetic correlations were observed between body size traits and fleshiness.

Conclusions:

• Genetic trends indicate an increase in body size and a decrease in fleshiness over the past decade.
• Rendena cattle are shifting towards characteristics of specialized milk-producing animals.
• Significant genetic variation remains for improving fleshiness, allowing for potential intervention.