Revista Colombiana de Ciencias Pecuarias (Sep 2013)
Prediction of basal endogenous losses of amino acids based on body weight and feed intake in pigs fed nitrogen-free diets
Abstract
Background: accurate estimations of basal endogenous losses (BEL) of amino acids (AA) are important for the calculation of standardized ileal digestibility values. Objectives: to address the influence of body weight (BW) and feed intake on BEL of crude protein (CP) and AA and to develop prediction equations for BEL of CP and AA in pigs fed nitrogen-free diets. Methods: based on data derived from 34 research papers, prediction equations for BEL of CP and AA were generated using BW and feed intake per maintenance feed intake (FI:MFI) based on energy concentration as independent variables. Results: initial BW (IBW) and FI:MFI ranged from 13.8 to 109.8 kg and from 1 to 5, respectively. Mean values for BEL of CP, Lys, Met, Thr, and Trp were 17.2 (CV = 50.9%), 0.42 (CV = 56.0%), 0.14 (CV = 80.8%), 0.55 (CV = 41.3%), and 0.14 (CV = 57.5%) g/kg dry matter intake (DMI), respectively. The FI:MFI was negatively correlated with BEL of CP and AA except Met (r < -0.39; p<0.05). Prediction equations for estimating the BEL of CP and AA (g/kg DMI) developed were: BEL of CP = 47.5 - (8.09 × 10-2 × IBW) - (8.83 × FI:MFI) with R² = 0.32 and p = 0.011; BEL of Lys = 0.979 - (1.00 × 10-3 × IBW) - (0.174 × FI:MFI) with R2 = 0.24 and p = 0.014; BEL of Thr = 1.09 - (1.82 × 10-3 × IBW) - (0.153 × FI:MFI) with R² = 0.28 and p = 0.007; and BEL of Trp = 0.552 - (1.11 × 10-3 × IBW) - (0.120 × FI:MFI) with R² = 0.47 and p = 0.002. Conclusion: based on the equations above, IBW and FI:MFI clearly decrease BEL of CP and AA. The equations provided in this paper may be used for estimating BEL of CP and AA.
