Genetic parameters for litter size, piglet growth and sow's early growth and body composition in the Chinese–European line Tai Zumu

Abstract

Genetics of piglet growth in association with sow's early growth and body composition were estimated in the Tai Zumu line. Piglet and sow's litter growth traits were calculated from individual weights collected at birth and at 3 weeks of age. Sow's litter traits included the number of piglets born alive (NBA), the mean piglet weight (MW) and the standard deviation of weights within the litter (SDW). Sow's early growth was measured by the age at 100 kg (A100), and body composition included backfat thickness (BF100). A main objective of this study was to estimate separately the direct genetic effect (d) and the maternal genetic effect (m) on piglet weight and daily weight gain during lactation. Variance components were estimated using the restricted maximum likelihood methodology based on animal models. The heritability estimates were 0.19 for NBA, 0.15 and 0.26 for SDW and MW at 3 weeks and 0.42 and 0.70 for A100 and BF100. The NBA was almost independent from SDW. Conversely, the A100 and BF100 were correlated unfavourably with SDW (rg <-0.24, SE<0.12). A stronger selection for litter size should have little effect on litter homogeneity in weights. Selection for lean growth rate tends to favour heterogeneity in weights. The direct effect on piglet weight at birth and daily weight gain accounted for 12% (h(²) (d) = 0.02) and 50% (h(²) (d) = 0.11) of the genetic variance, respectively. The association between d and m for piglet weight was not different from zero at birth (rg = 0.19, SE = 0.27), but a strong antagonism between d and m for daily weight gain from birth to 3 weeks was found (rg = -0.41, SE = 0.17). Substantial direct and maternal genetic effects influenced piglet growth until weaning in opposite way.

Genetic parameters and trends for production and reproduction traits of a Landrace herd in China

“…In this study, the performance records of one pig breeding herd in China were analyzed detailedly. The estimated heritabilities are comparable to that from other swine populations (Banville et al 2014;Li and Kennedy 1994; Roehe and Kennedy 1995), which are high for production traits (0.33-0.55), and low for reproduction traits (0.10-0.12, Table 2) in this study. For BF, the estimated heritability was 0.53 in a Canada Landrace population (Li and Kennedy 1994), 0.58 in an American swine population (Jiao et al 2014), and 0.72 in a Chinese-European line (Banville et al 2014), while it is 0.55 in this study ( Table 2).…”

“…The estimated heritabilities are comparable to that from other swine populations (Banville et al 2014;Li and Kennedy 1994; Roehe and Kennedy 1995), which are high for production traits (0.33-0.55), and low for reproduction traits (0.10-0.12, Table 2) in this study. For BF, the estimated heritability was 0.53 in a Canada Landrace population (Li and Kennedy 1994), 0.58 in an American swine population (Jiao et al 2014), and 0.72 in a Chinese-European line (Banville et al 2014), while it is 0.55 in this study ( Table 2). The estimated heritability for D100 ranged from 0.30 in a Canadian swine population (Li and Kennedy 1994) to 0.42 in a France population (Banville et al 2014), and it is 0.42 in this study (Table 2).…”

“…For ADG, the heritability is 0.44 in USA (Jiao et al 2014), 0.23 in Finland Landrace (Sevon-Aimonen et al 1997), and 0.34 in this Chinese swine herd (Table 2). For TNB and NBA, the estimated heritability is similar with that from literatures (Kapell et al 2011;Roehe and Kennedy 1995), though they are larger (~0.2) in some populations (Banville et al 2014;Hsu and Johnson 2014;Skorput et al 2014).…”

“…For BF, the estimated heritability was 0.53 in a Canada Landrace population (Li and Kennedy 1994), 0.58 in an American swine population (Jiao et al 2014), and 0.72 in a Chinese-European line (Banville et al 2014), while it is 0.55 in this study ( Table 2). The estimated heritability for D100 ranged from 0.30 in a Canadian swine population (Li and Kennedy 1994) to 0.42 in a France population (Banville et al 2014), and it is 0.42 in this study (Table 2). For ADG, the heritability is 0.44 in USA (Jiao et al 2014), 0.23 in Finland Landrace (Sevon-Aimonen et al 1997), and 0.34 in this Chinese swine herd (Table 2).…”

“…Estimates of heritability or environmental effects are a function of variance components and are population specific (Falconer and Mackay 1996). Such as the heritability of reproduction traits is ~0.1 in most population (Kapell et al 2011;Roehe and Kennedy 1995), while it is ~0.2 in several cases (Banville et al 2014;Hsu and Johnson 2014;Skorput et al 2014). Hence, population parameter estimates are essential in an efficient breeding system.…”