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Impact of Long Term Selection on Reproductive Efficiency in Linebred Rambouillet
Improving reproductive efficiency increases the profitability of livestock production. This study utilized a unique population of Rambouillet sheep that have been selected for high and low reproductive rate for over 40 years. Data were collected on reproductive performance, nutrient intake, and genetics. These high and low reproductive rate lines are genetically different as shown by PCA of 54K SNP genotypes. Reproductive performance differed between the lines in both litter size (P = 0.02) and kg lamb produced per ewe (P = 0.02). Intake was similar in the two lines, but the high line had a higher reproductive efficiency than the low line expressed as kg of TDN consumed per total kg of lamb produced (P = 0.007). This makes these populations ideally suited for investigating the genetic basis of reproductive efficiency.
Keywords: Reproduction, Genetics, Reproductive Efficiency
