Prediction of Nursery and Finishing Performance Based on Starting Nursery Weights

Abstract A total of 5 experiments were used to determine the relationship between nursery start weight and nursery/finishing performance traits. In each experiment, 48 pens containing 11 pigs/pen (0.65 m2/pig) were utilized. Age entering the nursery was 18-21 d and average BW was 5.9 kg. Pigs were blocked by BW and allotted to pens upon arrival and fed diets meeting or exceeding NRC (2012) recommendations. The nursery phase lasted between 42-45 d and pigs were marketed at a target weight of 136 kg. Pigs remained in the same pens from weaning to market. Data were analyzed using PROC REG/PROC CORR procedure in SAS. Pen served as experimental unit with a total of 240 observations. Nursery BW upon entry had positive (P < 0.01) correlations (r) with nursery end BW (0.57), ADG (0.23), and ADFI (0.30). There was a linear relationship between nursery starting BW and ending nursery BW [Ending BW = 1.09(nursery start BW, kg) + 9.0, R2 = 0.32, P < 0.001]. Starting nursery BW also was positively (P < 0.01) correlated with finishing end BW (0.58), ADG (0.21), ADFI (0.30), and negatively correlated with G:F (-0.25). A linear relationship was noted between starting nursery BW and market BW [Market BW = 3.93(nursery start BW, kg) + 85.6, R2 = 0.34, P < 0.001]. Linear relationships (P < 0.01) also were noted for nursery starting BW on finishing ADG, ADFI, and G:F. Finishing starting BW was positively correlated (P < 0.01) with market BW (0.52), ADG (0.32), and ADFI (0.37) and negatively correlated with G:F (-0.23). Starting finishing BW had a linear relationship with market BW [Market BW = 0.83(finishing start BW, kg) + 94.5, R2 = 0.27, P < 0.001]. Nursery starting BW has positive effects on growth performance in nursery and finishing phases as well as market weight.