Source Of Threonine Research Articles

Evaluation of a threonine fermentation product as a digestible threonine source in broilers

In the present experiment, a Thr fermentation product ( FP ) (75% minimum digestible Thr) was evaluated as a replacement for crystalline L-Thr (98.5% minimum digestible Thr) as a source of digestible Thr and other nutrients to support broiler performance (0–48 d) and processing characteristics. Five phase-fed diets included 1) a positive control ( PC ) diet containing L-Met, L-Lys•HCl, and L-Thr, 2) a reduced protein control ( RPC ) diet with added L-Val, L-Ile, and L-Arg, 3) a negative control ( NC ) identical to the RPC except that cellulose was added at the expense of L-Thr, 4) a RPC diet with Thr-FP used in place of L-Thr with only accounting for digestible Thr and energy contributions of the FP ( TFP ), and 5) a RPC diet with Thr-FP used in place of L-Thr and accounting for the full nutrient matrix of the FP ( TFP-FM ). Overall, broilers fed the RPC diet had similar growth performance compared to birds fed the PC diet, whereas broilers fed the NC diet had reduced BW gain and increased FCR compared to the RPC-fed birds. Birds fed either the TFP or TFP-FM diet had similar growth performance to the RPC-fed birds. At processing, broilers fed the RPC diet had similar parts yields, excluding wings, to the PC group. Parts yields for the Thr-FP and NC groups were similar to the RPC group. These data confirmed the importance of adequate dietary Thr concentration in maximizing broiler performance and that Thr provided by the Thr-FP supported equivalent performance to L-Thr.

176 Evaluation of a novel threonine source for nursery pig diets

Abstract Four hundred and eighty (PIC 337 X 1050, PIC Genus, Hendersonville, TN) pigs were used to evaluate a novel threonine source (ThrPro, CJ America-Bio, Fort Dodge, IA) for nursery pigs from approximately 7 kg to 20 kg. At weaning, pigs were sorted by gender and fed a common diet for one week. Upon completion of the first week, pigs were sorted into randomized complete blocks, equalized by weight, within 16 replications. Pigs were allocated to one of three dietary treatments: positive control (POS)-SID LYS:THR 0.60, negative control (NEG)-SID LYS:THR ≤0.46 and alternative threonine source (TEST)-SID LYS:THR 0.60. All other nutrients met or exceeded the NRC (2012) recommendations. Growth and intake data were analyzed using PROC MIXED procedure in SAS. The experimental unit was the pen. During the first 14 days, pigs fed TEST had similar ADG (0.417 vs. 0.414 kg/d, P=0.81) and G:F (0.977 vs. 1.030, P=0.18) compared to POS, and increased ADG (0.417 vs. 0.387 kg/d, P=0.01) and G:F (0.977 vs. 0.898, P=0.05) compared to NEG. Over days 14-28, pigs fed TEST had similar ADG (0.523 vs. 0.532 kg/d, P=0.49) and G:F (0.712 vs. 0.707, P=0.71) compared to POS, and increased ADG (0.523 vs. 0.479 kg/d, P=0.002) and G:F (0.712 vs. 0.627, P< 0.0001) compared to NEG. Overall (d 0 to 28), pigs fed TEST had similar ADG (0.466 vs. 0.474 kg/d, P=0.48) and G:F (0.808 vs. 0.816, P=0.55) compared to POS, and increased ADG (0.466 vs. 0.433 kg/d, P=0.002) and G:F (0.808 vs. 0.725, P< 0.0001) compared to NEG. ADFI was not significantly different across treatments for the entirety of the study. In conclusion, the replacement of L-threonine with a novel threonine source resulted in similar growth performance in nursery pigs from approximately 7 kg to 20 kg.

Evaluation of a novel threonine source for nursery pig diets.

Four hundred and eighty (PIC 337 X 1050, PIC Genus, Hendersonville, TN) pigs were used to evaluate a novel threonine source (ThrPro, CJ America Bio, Fort Dodge, IA) for nursery pigs from approximately 7 to 20 kg body weight (BW). After weaning, pigs were sorted by sex and fed a common diet for 1 wk. Upon completion of the first week, pigs were sorted into randomized complete blocks, equalized by weight, within 16 replications. Pigs were allocated to one of three dietary treatments: positive control (POS)—standard ileal digestible threonine-to-lysine ratio (SID; Thr:Lys) 0.60, negative control (NEG)—SID Thr:Lys ≤0.46, and alternative Thr source (TEST)—SID Thr:Lys 0.60. The alternative Thr source included fermentative biomass and was assumed to contain 75% Thr and a digestibility coefficient of 100% based on the manufacturer’s specifications. All other nutrients met or exceeded the NRC recommendations. Growth and intake data were analyzed as repeated measures with a compound symmetry covariance structure using the MIXED procedure in SAS 9.4 (SAS Institute Inc., Cary, NC) with pen as the experimental unit. Treatment, phase, the interaction between treatment and phase, and block were included as fixed effects in the model. Differences in total removals were tested using Fisher’s Exact Test of PROC FREQ. Results were considered significant at P ≤ 0.05 and considered a trend at P > 0.05 and P ≤ 0.10. During the first 14 d, pigs fed TEST had decreased gain-to-feed ratio (G:F; 0.77 vs. 0.80, P = 0.022) compared to POS and increased G:F (0.77 vs. 0.73, P < 0.001) compared to NEG. Over days 14–28, pigs fed TEST had similar G:F (0.71 vs. 0.70, P = 0.112) compared to POS and increased G:F (0.71 vs. 0.63, P < 0.001) compared to NEG. Overall (days 0–28), pigs fed TEST had similar average daily gain (ADG; 0.47 vs. 0.47 kg/d, P = 0.982) and G:F (0.76 vs. 0.74, P = 0.395) compared to POS and increased ADG (0.47 vs. 0.43 kg/d, P < 0.001) and G:F (0.76 vs. 0.67, P < 0.001) compared to NEG. The average daily feed intake was not significantly different across treatments for the entirety of the study. In conclusion, the replacement of crystalline L-Thr with a novel Thr source resulted in similar growth performance in nursery pigs from approximately 7 to 20 kg.

Utilization of ileal digestible amino acids by growing pigs: threonine

An experiment was conducted to determine the utilization of ileal digestible threonine by growing pigs. Three threonine-deficient diets (0.22 g ileal digestible threonine/MJ digestible energy (DE] were formulated using cottonseed meal, meat-and-bone meal and soya-bean meal respectively, as the only source of threonine in the diet. An additional three diets were formulated with supplements of threonine to confirm that threonine was limiting in the first three diets. The growth performance and retention of threonine by pigs given the six diets over the 20-45 kg growth phase was then determined. Growth rates (g/d) of the pigs given the three diets formulated to 0.22 g ileal digestible threonine/MJ DE were significantly different (P less than 0.001): cottonseed meal 417, meat-and-bone meal 452, soya-bean meal 524 (SED 13.6). The response of pigs to the addition of threonine confirmed that threonine was limiting in these diets. Crude protein (nitrogen x 6.25) deposited by the pigs (g/d) was significantly higher (P less than 0.001) for those given soya-bean meal (75), relative to meat-and-bone meal (62) and cottonseed meal (47) (SED 3.3). The proportion of ileal digestible threonine retained by pigs given the three protein concentrates was: cottonseed meal 0.44, meat-and-bone meal 0.59, soya-bean meal 0.64 (SED 0.024). These results indicate that values for the ileal digestibility of threonine in protein concentrates are unsuitable in dietary formulations as the assay does not reflect the proportion of threonine that can be utilized by the pig. It appears that, with heat-processed meals, a considerable proportion of the threonine is absorbed in a form(s) that is (are) inefficiently utilized.

Specialized peptide transport system in Escherichia coli.

Trileucine is utilized as a source of leucine for growth of strains of Escherichia coli K-12 that are deficient in the oligopeptide transport system (Opp). Trithreonine is toxic to E. coli K-12. Opp- mutants of E. coli K-12 retain complete sensitivity to this tripeptide. Moreover, E. coli W, which is resistant to trithreonine, can utlize this tripeptide as a threonine source and this capability is fully maintained in E. coli W (Opp-). A spontaneous trithreonine-resistant mutant of E. coli K-12 (Opp-) has been isolated that has an impaired growth response to trileucine and is resistant to trithreonine. Trileucine competes with the uptake of trithreonine as measured by its ability to relieve trithreonine toxicity in E. coli K-12. It is concluded that trileucine as well as trithreonine are transported into E. coli K-12 or W by a common uptake system that is distinct from the Opp system. Trimethionine can act as a competitor of trileucine or trithreonine-supported growth and as an antagonist of trithreonine toxicity in Opp- mutants. It is concluded that trimethionine is recognized by the trileucine-trithreonine transport system. Trithreonine, trimethionine, and trileucine are also transported by the Opp system, as they all relieve triornithine toxicity towards E. coli W and compete with tetralysine utilization as lysine source for growth of a lysine auxotroph of this strain.