Figure 1.
Figure 1.

Estimated standardized ileal digestible (SID) Ile:Lys ratio requirement for ADG of nursery pigs, Exp. 1. QP: BIC = 558.3; Estimated 64.7% SID Ile:Lys that maximized ADG; [95% CI: (51, > 65%)]; 99% of Max ADG at 57.0% SID Ile:Lys. BLL: BIC = 556.6; Estimated breakpoint: 52.0% SID Ile:Lys; [95% CI:(51.96, 52.04)]. BLQ: BIC = 557.9; Estimated breakpoint: 52.0% SID Ile:Lys; [95% CI:(51.97, 52.03)]. A total of 280 nursery pigs (PIC 327 × 1,050, initially 6.7 ± 0.08 kg BW) were used in a 26-d growth trial with 5 pigs per pen and 8 pens per treatment. Pigs were weaned at approximately 21 d, fed a common starter diet for 6 d post-weaning, then placed on experimental diets. Experimental diets were fed from d 0 to 12 and a common diet was fed from d 12 to 26. Quadratic polynomial (QP), broken-line linear (BLL), and broken-line quadratic (BLQ) models were fit for the experimental period to estimate SID Ile:Lys. Bayesian Information Criterion (BIC) was used to determine the best fitting models; a lower value indicates a better fit to the data.

 


Figure 2.
Figure 2.

Estimated standardized ileal digestible (SID) Ile:Lys ratio requirement for ADFI of nursery pigs, Exp. 1. QP: BIC = 604.4; Estimated 56.2% SID Ile:Lys that maximized ADFI [95% CI: (48, > 65%)]; 99% of Max ADFI at 51.6% SID Ile:Lys. BLL: BIC = 603.8; Estimated breakpoint: 50.6% SID Ile:Lys; [95% CI:(41.99, 59.15)]. A total of 280 nursery pigs (PIC 327 × 1,050, initially 6.7 ± 0.08 kg BW) were used in a 26-d growth trial with 5 pigs per pen and 8 pens per treatment. Pigs were weaned at approximately 21 d, fed a common starter diet for 6 d post-weaning, then placed on experimental diets. Experimental diets were fed from d 0 to 12 and a common diet was fed from d 12 to 26. Quadratic polynomial (QP), broken-line linear (BLL), and broken- line quadratic (BLQ) models were fit for the experimental period to estimate SID Ile:Lys ratio to maximize ADFI. Bayesian Information Criterion (BIC) was used to determine the best fitting models; a lower value indicates a better fit to the data.

 


Figure 3.
Figure 3.

Estimated standardized ileal digestible (SID) Ile:Lys ratio requirement for ADG of nursery pigs, Exp. 2. QP: BIC = 543.3; Estimated 58.3% SID Ile:Lys that maximized ADG; [95% CI: (49, > 65%)]; 99% of Max ADG at 54.3% SID Ile:Lys. BLL: BIC = 541.8; Estimated breakpoint: 51.8% SID Ile:Lys; [95% CI: (47.65, 55.93)]. A total of 280 nursery pigs (DNA 600 × 241, initially 6.0 ± 0.27 kg BW) were used in a 32-d growth trial with 5 pigs per pen and 8 pens per treatment. Pigs were weaned at approximately 20 d of age. One replication was fed a common starter diet for 3 d due to increased weaning BW, and the other seven replications were fed a common starter diet for 6 d post-weaning, then placed on experimental diets. Experimental diets were fed from d 0 to 18 and a common diet was fed from d 18 to 32. Quadratic polynomial (QP), broken-line linear (BLL), and broken-line quadratic (BLQ) models were fit for the experimental period to estimate SID Ile:Lys ratio to maximize ADG. Bayesian Information Criterion (BIC) was used to determine the best fitting models; a lower value indicates a better fit to the data.

 


Figure 4.
Figure 4.

Estimated standardized ileal digestible (SID) Ile:Lys ratio requirement to maximize ADFI for nursery pigs, Exp. 2. QP: BIC = 591; Estimated 57.2% SID Ile:Lys that maximized ADFI; [95% CI: (49, > 65%)]; 99% of Max ADFI 53.5% SID Ile:Lys. BLQ: BIC = 591.7; Estimated breakpoint: 52.0% SID Ile:Lys; [95% CI:(51.95, 52.05)]. A total of 280 nursery pigs (DNA 600 × 241, initially 6.0 ± 0.27 kg BW) were used in a 32-d growth trial with 5 pigs per pen and 8 pens per treatment. Pigs were weaned at approximately 20 d of age. One replication was fed a common starter diet for 3 d due to in- creased weaning BW, and the other seven replications were fed a common starter diet for 6 d post-weaning, then placed on experimental diets. Experimental diets were fed from d 0 to 18 and a common diet was fed from d 18 to 32. Quadratic polynomial (QP), broken-line linear (BLL), and broken-line quadratic (BLQ) models were fit for the experimental period to estimate SID Ile:Lys ratio to maximize ADFI. Bayesian Information Criterion (BIC) was used to determine the best fitting models; a lower value indicates a better fit to the data.