Genetic correlations between reproduction and production traits in swine1

Abstract

Genetic correlations between reproduction and production traits were estimated in swine. Reproduction traits investigated were age at first service (AFS), number of live-born piglets in the first litter (NBA1), interval from weaning to first service after first litter (WTS1), number of live-born piglets in the second litter (NBA2), and interval from weaning to first service after the second litter (WTS2). Females generating the data were Norwegian Landrace born in nucleus herds between 1990 and 2000, and the number of records ranged from 13,792 to 56,932. Genetic correlations were estimated among the main production traits in the breeding goal: adjusted age at 100 kg live weight (A100), percentage of lean meat content (LMC), individual feed consumption from 25 to 100 kg (FC), and bacon side quality (BSQ). Average adjusted backfat thickness (BF) was included as a production trait. The A100 and BF traits were recorded on gilts on-farm with 190,454 records, whereas LMC, BSQ, and FC were recorded on-station with the number of records ranging from 12,487 to 12,992. Analyses were carried out with a multivariate animal model using average information restricted maximum likelihood procedures by first running each reproduction trait with A100 and BF, followed by each reproduction trait with LMC, BSQ, and FC. Average heritabilities for reproduction traits were as follows: AFS (0.38), NBA1 (0.11), WTS1 (0.06), NBA2 (0.12), and WTS2 (0.03); and for production traits: A100 (0.30), BF (0.44), FC (0.22), LMC (0.58), and BSQ (0.23). The highest genetic correlation was estimated between A100 and AFS (r(g)= 0.68), also resulting in a positive genetic correlation between FC and AFS. Growth (A100) was negatively (i.e., unfavorably) genetically correlated to NBA1 and NBA2 (r(g) = 0.60 and rg = 0.42 respectively), and so the genetic correlation to FC also became unfavorable (r(g)= 0.23 and r(g) = 0.20). Single-trait selection for enhanced LMC would also affect NBA1 and NBA2 unfavorably (r(g)= -0.12 and r(g)= -0.24). Correlations between BF at 100 kg live weight and reproduction traits were close to zero; however, a low genetic correlation between BF and WTS1 was obtained (r(g)= -0.12), indicating that selection toward reduced BF at 100 kg live weight may have an unfavorable impact on WTS1.

Simultaneous estimation of genetic parameters for production and litter size traits in Czech Large White and Czech Landrace pigs

“…Especially in CLW, low negative genetic correlations were found between both litter size traits and average daily gain in the present investigation. This is in agreement with Hermesch et al (2000), Chen et al (2003), and to a certain degree with Holm et al (2004). The latter authors estimated relatively high correlations of approximately 0.50 between the number of piglets born alive and adjusted age at 100 kg of live weight, which means also negative correlations between litter size and growth rate.…”

Genetic parameters for feed intake, litter weight, body condition and rebreeding success in primiparous Norwegian Landrace sows

“…Despite the transformation, the distribution of WSI50 was still skewed (Figure 1). The estimated heritabilities in this study for WSI7 (h 2 = 0.12, PSD = 0.05) and WSI50 (h 2 = 0.14, PSD = 0.05) were slightly higher than earlier reported estimates (0.03 to 0.08) from the same population (Holm et al, 2004;Lundgren et al, 2010). Adamec and Johnson (1997) reported a heritability of 0.14 for weaning-to-service interval analysed with no upper limit of days.…”

Genome‐wide association study for reproductive traits in a Large White pig population

“…Traditional breeding technologies based on best linear unbiased prediction (Holm et al . 2004) is limited for significant genetic improvement of these reproductive traits due to their low heritability (Chen et al . 2003).…”