PSIX-10 Effects of SID Lysine:Calorie NE ratio on the Growth Performance and Carcass Characteristics of DNA 600 Sired Pigs

Abstract A total of 2,673 mixed sex pigs (DNA 600 × PIC 1050; initially 21.4 kg BW) were used in a 117-d study to evaluate the effects of increasing SID Lysine:Calorie NE ratio on the growth performance and carcass characteristics of DNA sired pigs. Pens of pigs (30 pigs/pen) were blocked by BW and location and allotted to 1 of 4 dietary treatments with 18 pens per treatment. Treatments were 90%, 95%, 100%, or 105% of the 2016 PIC recommended SID Lysine:Calorie NE ratio for finishing gilts. Data were analyzed as a randomized complete-block design with pen as the experimental unit. Overall (d 0-117), increasing Lysine:Calorie NE tended to improve ADG (Linear; P = 0.077) and G:F (Linear; P = 0.053). Although there was an increase in ADG with increasing SID Lysine:Calorie NE, there was no evidence for a difference (P > 0.100) in final BW. The lack of BW response is most likely due to the lower (Quadratic; P < 0.008) removal rate as SID Lysine:Calorie NE increased. Carcass ADG (Linear; P < 0.064) tended to improve as SID Lysine: Calorie NE increased. An improvement in carcass G:F (Quadratic; P < 0.004) was observed as SID Lysine:Calorie NE increased to 100% PIC (2016) recommendations, with little improvement observed thereafter. No significant differences were observed in carcass yield, loin depth, back fat, or % lean. These results suggests that DNA sired pigs fed increasing SID Lysine:Calorie NE ratios tended to have improved growth performance with no impact on carcass quality.