Search

Our objective was to determine the effects of increasing dietary standardized ileal digestible lysine levels on the growth performance of PIC 337 × Camborough commercial pigs that were sired by highindex boars. A total of 2,200 barrows and gilts (PIC 337 × Camborough) were used in six experiments covering body weight ranges of 11-25 kg (Exp.1), 26-46 kg (Exp.2), 45-66 kg (Exp.3), 63-85 kg (Exp.4), 86-110 kg (Exp.5), and 108-134 kg (Exp.6). Pigs were placed in two rooms with 45 pens in Room 1 and 43 pens in Room 2, and there were 25 pigs/pen (12 or 13 gilts and 13 or 12 barrows) for both rooms. Room 1 was used in Exp. 1, 3, and 5; Room 2 was used in Exp. 2, 4, and 6. At the beginning of each trial, on-test pens were blocked by body weight and randomly allotted to one of five treatments (90, 100, 105, 110, or 120% of PIC SID Lys recommendations for Exp.1 to Exp. 5; whereas 80, 90, 100, 110, or 120% of PIC SID Lys recommendations for Exp. 6) in a randomized complete block design. Off-test pens were fed a common wash-out diet between trials, and common diets were formulated to meet PIC nutrient requirements according to the specific weight range. Data were analyzed using generalized linear mixed model with pen as the experimental unit in R Studio (Version 3.5.2, R Core Team; Vienna, Austria). Dietary SID Lys levels were included as fixed effects, and weight block was included as random effects in the model. All data are reported as least square means and considered statistically significant at P < 0.05 and marginally significant at P < 0.10. Increasing SID Lys improved average daily gain (ADG; linear, P = 0.003) and gain-to-feed ratio (G:F; quadratic, P = 0.007) in Exp.1; improved ADG (quadratic, P = 0.045) in Exp.4; improved ADG (quadratic, P = 0.009) and G:F (quadratic, P = 0.002) in Exp.5; and improved ADG (linear, P = 0.037) and G:F (linear, P = 0.030) in Exp.6 (Table 1). However, there was no evidence for difference among treatments on growth performance in Exp.2 and 3. With increasing dietary SID Lys levels, gram of SID Lys per kilogram of bodyweight gain and 5 (P = 0.002); and increased in a linear manner in Exp.2, 3, 4, and 6 (P < 0.001). In conclusion, increasing dietary SID Lys levels improved the growth performance of PIC 337 × Camborough commercial pigs sired by high-index boars when the bodyweight was below 25 kg or beyond 63 kg. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate growth performance and economic return of PIC 800 × Camborough pigs fed increasing SID Lys from approximately 12- to 136-kg. Pens of pigs were blocked by body weight (BW) and randomly assigned to 1 of 5 dietary treatments in a randomized complete block design with 26 pigs per pen and 16 pens per treatment. Pens were provided 1 of 5 dietary treatments with increasing SID Lys at 85, 93, 100, 107, and 115% of current (2021) PIC recommendations within 6 dietary phases as follows: phase 1 (1.09, 1.19, 1.28, 1.36, and 1.47%), phase 2 (0.97, 1.06, 1.14, 1.22, and 1.32%), phase 3 (0.87, 0.95, 1.02, 1.09, and 1.17%), phase 4 (0.75, 0.82, 0.88, 0.94, and 1.01%), phase 5 (0.66, 0.72, 0.77, 0.82, and 0.89%), and phase 6 (0.59, 0.64, 0.69, 0.74, and 0.79%). Two corn-soybean meal-based diets containing low and high Lys were blended to achieve target SID Lys levels for each treatment diet within phase. Overall (d 0 to 143), increasing SID Lys improved (linear, P = 0.007) ADG and G:F, but did not impact ADFI (P > 0.10; Table). A tendency (linear, P = 0.067) for heavier hot carcass weights (HCW) was observed in pigs fed increasing SID Lys. However, there was no evidence for differences (P > 0.10) in carcass yield, backfat depth, loin depth, or carcass lean percentage across treatments. The linear (LM) model served as the best fit for both growth and economic parameters. The LM model predicted maximum ADG and G:F at levels greater than 115% of PIC's current recommendations. However, for income over feed cost (IOFC), the LM model predicted maximum profitability at or below 85% of the current Lys recommendations of PIC. In conclusion, the optimal SID Lys level for PIC 800 × Camborough pigs from 12- to 136-kg differed upon response criteria, with growth performance maximized at levels at or above 115% of the recommendation for SID Lys by PIC; however, maximal economic returns were observed at or below 85% of PIC's current SID Lys recommendations. [ABSTRACT FROM AUTHOR]

Our objective was to determine the effects of increasing dietary standardized ileal digestible (SID) lysine (Lys) on the growth performance of grow-finish pigs. A total of 1,120 pigs (PIC 337×Camborough, initially 39.0±0.82 kg) were used in a 77-d study. Pigs used in the study were sired by boars ranked in the top 15% of a selected PIC elite boar stud based on index. Pens of pigs were blocked by body weight and randomly allotted to 1 of 5 treatments, which consisted of 85, 95, 105, 115, and 125% of the PIC2016 SID Lys recommendations within each phase. Diets were corn-soybean meal-based and formulated to be isocaloric. Treatments were achieved with increasing feedgrade amino acids. There were 9 mixed-gender pens per treatment and 24 or 25 pigs per pen. Data were analyzed using generalized linear and nonlinear mixed models with pen as the experimental unit. Competing models included linear, quadratic polynomial (QP), broken-line linear (BLL), and broken-line quadratic (BLQ). Increasing dietary SID Lys from 85 to 125% marginally improved overall average daily gain (ADG, quadratic, P = 0.056), gain to feed ratio (G:F, quadratic, P = 0.062), and final body weight (linear, P = 0.075). There was no evidence for treatment effects on mortality and removals (P > 0.10). The best-fitting models for ADG were QP and BLL. The QP model estimated the maximum ADG at 110.6% (95% CI: 93 to >125%), with 99% of maximum ADG achieved at 97.4%. The BLL plateau was estimated at 105.0% (95% CI: 74 to 136%). The best-fitting model for G:F was QP, estimating the maximum G:F at 107.8% (95% CI: 92 to >125%). In conclusion, the estimated optimum overall SID Lys for 39- to 119-kg pigs sired by high index boars ranged from 105.0 to 110.6% of PIC2016 SID Lys recommendation within each phase, depending on the response criteria and statistical model. [ABSTRACT FROM AUTHOR]

Our objective was to determine the effects of increasing dietary standardized ileal digestible (SID) lysine (Lys) on the growth performance of late nursery pigs. A total of 1,125 pigs (PIC 337×Camborough, initially 12.0±0.66 kg) were used in a 21-d study. The pigs used in the study were sired by boars ranked in the top 15% of a selected PIC elite boar stud based on index. Pens of pigs were blocked by body weight and randomly allotted to 1 of 5 treatments containing 0.95, 1.10, 1.20, 1.35, and 1.50% of SID Lys. Diets were corn-soybean mealbased and contained 2,480 Kcal of NE/kg. Treatments were achieved with increasing feed-grade amino acids. There were 9 mixed gender pens per treatment and 25 pigs per pen. Data were analyzed using generalized linear and nonlinear mixed models with pen as the experimental unit. Competing models included linear, quadratic polynomial (QP), broken-line linear (BLL), and broken-line quadratic (BLQ). Increasing SID Lys concentration improved average daily gain (ADG, linear, P < 0.001) and gain to feed ratio (G:F, quadratic, P = 0.011). The best-fitting models for ADG were QP and BLL. The QP model estimated the maximum ADG at 1.43% (95% CI: 1.12 to >1.50%), with 99% of maximum ADG achieved at 1.27%. The BLL plateau was estimated at 1.31% (95%CI: 1.06 to >1.50%). The best-fitting models for G:F were QP, BLL, and BLQ. The QP model estimated the maximum G:F at 1.48% (95%CI: 1.23 to >1.50%), with 99% of maximum G:F achieved at 1.24%. The BLL plateau was estimated at 1.30% (95% CI: 1.18 to 1.41%), whereas the BLQ plateau was estimated at 1.36% (95%CI: 1.14 to >1.50%). In conclusion, the estimated optimum SID Lys concentration for 12- to 26-kg pigs sired by high index boars ranged from 1.30 to 1.48%, depending on the response criteria and statistical model. [ABSTRACT FROM AUTHOR]