Bioavailability of threonine and tryptophan in peanut meal for starter pigs using slope-ratio assay

Abstract

The objective of the two studies was to determine the bioavailability of threonine (thr) and tryptophan (trp) in peanut meal, relative to L-thr and L-trp, for starter pigs using the slope-ratio bioassay. Basal diets (BDs) contained surfeit amounts of all amino acids for 10 to 20 kg pigs, except for thr (Experiment 1) or trp (Experiment 2). In the first study, four reference diets were formulated by supplementing the BD with 0, 0.4, 0.8 or 1.2 g of L-thr/kg at the expense of cornstarch; two test diets were formulated by replacing cornstarch in the BD with peanut meal at 32 or 64 g/kg of diet to supply 0.4 or 0.8 g thr/kg, respectively. Four reference diets consisting of the BD supplemented with 0, 0.15, 0.3 or 0.45 g of L-trp/kg at the expense of cornstarch and two test diets in which cornstarch in the BD was replaced with peanut meal at 30 or 60 g/kg of diet to supply 0.14 or 0.28 g trp/kg, respectively were used in the second study. Body weight gain responded in a linear way to supplemental L-thr or thr from peanut meal ( P , 0.001). There was a linear response ( P , 0.001) to thr supplementation from L-thr or peanut meal in gain-to-feed ratio. The addition of trp to the BD linearly increased ( P , 0.05) body weight gain, feed intake and gainto-feed ratio regardless of the trp source. Common-intercept, multiple linear regression in slope-ratio methodology using weight gain or gain-to-feed ratio as dependent variables and supplemental thr intake as independent variable gave relative bioavailability estimates of 71.9% or 75.7%, respectively. Corresponding values for trp were 92% and 75.7%. The fiducial limits for none of the relative bioavailability estimates included 100%. The data from these studies suggest that the bioavailabilities of thr and trp in peanut meal are less than those of L-thr and L-trp, and that the bioavailabilities of thr and trp in peanut meal are 72% to 76% and 76% to 92%, respectively.

0958 Bioavailability of D-methionine relative to L-methionine for nursery pigs using slope-ratio assay

“…Growth performance has generally been used as response criteria for AA bioavailability assay (Chung & Baker, 1992;Adeola, 2009;Shen, Weaver & Kim, 2014). However, in the present study, growth responses to the supplemental Met were not significant among dietary treatments while N balance responses were affected by the supplemental Met.…”

“…Nutrient bioavailability assay provides relative information on the capacity of feed ingredients to supply a nutrient capable of being digested, absorbed and available for use or storage (Gabert, Jorgensen & Nyachoti, 2001;Adeola, 2009). Growth performance has generally been used as response criteria for AA bioavailability assay (Chung & Baker, 1992;Adeola, 2009;Shen, Weaver & Kim, 2014).…”

Determination and prediction of the energy content and amino acid digestibility of peanut meals fed to growing pigs

“…The use of PNM as an alternative protein source has been evaluated in poultry (Costa et al 2001;Pesti et al 2003), pigs (Orok et al 1975;Balogun and Koch 1979;Adeola 2009) and shrimp (Liu et al 2012). The variable effects of PNM on performance may be the result of limited data on the energy content and amino acid digestibility of PNM to allow more accurate feed formulation.…”

Application of the slope‐ratio growth assay technique to estimate tryptophan availability in soybean meal fed to young rats

“…The results of the preliminary study were analyzed by a broken‐line model (Anderson & Nelson, ; Baker, Allen, Boomgaardt, Graber, & Norton, ) to determine the range of the linear response of weight gain to supplemental Trp intake for the slope‐ratio technique. Experimental data were subjected to regression analysis with JMP software, and tryptophan availability in SBM was estimated using common intercept multiple linear regression and the slope‐ratio technique (Adeola, ; Baker et al, ; Finney, ; Kosaka & Yoshida, ). Supplemental Trp intake (mg/day, mg/3days) was used as an independent valuable, and weight gain (g/day) and NRR (%) were used as dependent valuables to estimate Trp availability.…”

“…Traditionally the slope‐ratio growth assay has been known to be useful to estimate AA availability in pig (Adeola, , ; Copelin, Gaskins, & Tribble, ; Rivera, Peo, Stahly, Moser, & Cunningham, ; Sato, Kobayashi, Jones, & Easter, ; Yen, Baker, Harmon, & Jensen, ), chick (Ousterhout, Grau, & Lundholm, ; Robel & Frobish, ; Smith, ) and rat (Gupta & Elvehjem, ; Yen et al, ). To determine the availability of Trp using the slope‐ratio assay method, however, several factors should be considered.…”