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Effects of standardized ileal digestible valine:lysine ratio on nursery pig performance

Monday, March 14, 2016: 2:15 PM
302-303 (Community Choice Credit Union Convention Center)
Annie B. Clark , Kansas State University, Manhattan, KS
M. D. Tokach , Kansas State University, Manhattan, KS
S. S. Dritz , Kansas State University, Manhattan, KS
K. J. Touchette , Ajinomoto Heartland, Inc., Chicago, IL
M. A. D. Gonçalves , Kansas State University, Manhattan, KS
J. M. DeRouchey , Kansas State University, Manhattan, KS
R. D. Goodband , Kansas State University, Manhattan, KS
J. C. Woodworth , Kansas State University, Manhattan, KS
Abstract Text:

A total of 280 pigs (PIC 327 × 1050; initially 6.53 kg BW) were used in a 28-d trial to evaluate the effects of increasing standardized ileal digestible (SID) Val:Lys ratio on nursery pig growth performance. Pigs were weaned at 21 d of age and 5 pigs allotted to each nursery pen according to BW and gender. A common diet was fed for 5 d when pens were assigned to 1 of 7 dietary treatments in a randomized block design with 8 pens per treatment. Experimental diets were fed from d 0 to 14 followed by a common diet from d 14 to 28. The 7 dietary treatments were 50, 57, 63, 68, 73, 78, and 85% SID Val:Lys. A prior experiment demonstrated a Lys requirement of 1.44 and 1.45% SID Lys for ADG and G:F, respectively, for pigs in this facility. Thus, diets were formulated to 1.24% SID Lys to ensure pigs were below the Lys requirement. As SID Val:Lys increased, ADG, ADFI, and G:F increased (quadratic, P<0.05). Growth response variables were fitted using linear and non-linear dose-response models with pen as the experimental unit and initial BW as a covariate with ADG and G:F fitted using heterogeneous and homogenous residual variance, respectively. Models fit were quadratic polynomial (QP), broken-line linear (BLL), and broken-line quadratic with best fit determined according to Bayesian information criterion. For ADG, the best fitting model was BLL and maximum ADG was achieved with a minimum of 62.9% SID Val:Lys (95% CI: [52.2, 73.7%]). For G:F, the best fitting model was QP [0.010294+0.017526*(Val:Lys)–0.000122*(Val:Lys)2] using a 6.53 kg initial BW. This resulted in a maximum G:F at 71.7% SID Val:Lys and 99% of maximum achieved at a 64.4% ratio. In summary, the SID Val:Lys requirement ranged from 62.9 to 71.7% depending on the response model.

 

 

SID Val:Lys, %

 

Probability, P <

Item:

50

57

63

68

73

78

85

SEM

Linear

Quadratic

d 0 to 14

 

 

 

 

 

 

 

 

 

 

   ADG, g

190

221

249

249

248

251

238

11.2

0.001

0.001

   ADFI, g

331

363

394

388

403

390

386

17.2

0.012

0.030

   G:F

0.579

0.613

0.635

0.646

0.614

0.645

0.617

0.0189

0.101

0.039

Keywords: valine, amino acids, nursery pigs