Total Sulfur Amino Acid Requirement Research Articles

Total sulfur amino acid requirement of healthy school-age children as determined by indicator amino acid oxidation technique

Current total sulfur amino acid (TSAA) requirements of children are based on a factorial estimate that involves several assumptions. The objective was to determine the TSAA requirement (methionine alone) of healthy school-age children by measuring the appearance of 13CO2 (F13CO2) in breath after the oxidation of l-[1-13C]phenylalanine in response to graded methionine intakes. Six healthy school-age children randomly received each of 6 methionine intakes (0, 5, 10, 15, 25, and 35 mg.kg(-1).d(-1)) along with an amino acid mixture to give a final protein intake of 1.5 g.kg(-1).d(-1) and an energy intake of 1.7 x resting energy expenditure. The diet was devoid of cysteine. The mean TSAA requirement was determined by applying a biphase linear regression crossover analysis on F13CO2 data, which identified a breakpoint at minimal F13CO2 in response to graded methionine intakes. The mean and population-safe (upper 95% CI) intakes of TSAA (as methionine) were determined to be 12.9 and 17.2 mg.kg(-1).d(-1), respectively. The current study suggests that children of this age group have a mean TSAA requirement similar to that of adults (12.6 mg.kg(-1).d(-1)). Therefore, it is valid to use a factorial approach, which assumes that maintenance requirements in childhood are similar to adult requirements, to estimate TSAA requirements in school-age children.

Determining the total sulfur amino acid to lysine requirement of the lactating sow (2006)

A total of 163 sows were used in a study to determine the requirement for total sulfur amino acids (TSAA), relative to lysine, during lactation. All experimental diets were cornsoybean meal-based and formulated to contain 0.88% true ileal digestible (TID) lysine (0.97% total lysine). The experimental diets contained 0.37% L-lysine HCl, with other crystalline amino acids added to ensure that TSAA was first limiting. The dietary TID TSAA rates were formulated to 0.44, 0.48, 0.53, 0.57, and 0.62%, corresponding to 50, 55, 60, 65, and 70% of lysine, respectively. Sows farrowed in six farrowing groups, and were randomly allotted to the dietary treatments on the basis of parity. Over the entire lactation period, there were no differences (P>0.14) in ADFI, weight loss, backfat loss, or plasma urea nitrogen among sows fed increasing TSAA:Lys ratios. Increasing TSAA, relative to lysine, had no effect (P>0.25) on litter weaning weight or preweaning mortality. In summary, there were no differences in litter performance with increasing TID TSAA:Lys ratio. These results suggest that the requirement for TID TSAA is no more than 50% of lysine. Additional research is needed to confirm this relatively low TSAA requirement, and that the relatively high feed (and amino acid) intake of sows, coupled with possible tissue breakdown as a source of TSAA, did not decrease the dietary requirement.

The optimal true ileal digestible lysine and total sulfur amino acid requirement for nursery pigs between 20 and 50 lb (2005)

An experiment involving 360 pigs (PIC, avg. BW = 22.0 lb) was conducted to determine the appropriate true ileal digestible (TID) lysine and total sulfur amino acid (TSAA) requirement of nursery pigs and, consequently, to determine the optimal TSAA:lysine ratio. This trial was organized as a combination of two simultaneous experiments, with one set of diets consisting of five increasing TID lysine concentrations (1.05, 1.15, 1.25, 1.35, and 1.45%) and the second set of diets consisting of five increasing TID TSAA concentrations (0.61, 0.69, 0.76, 0.83, and 0.90%). The highest concentrations of both lysine and TSAA (1.45% and 0.90%, respectively) were combined as one diet and used in both the lysine and TSAA titrations, to give a total of 10 treatments. Pigs were randomly allotted to eight replications, with five pigs per pen, on the basis of initial BW. Average daily gain and F/G improved (quadratic, P<0.01) with increasing TID lysine. The largest improvement in growth rate and feed efficiency for PIC pigs in these facilities occurred as the TID lysine increased to 1.25 and 1.35%, respectively; there was little improvement in performance thereafter. Increasing TID TSAA increased (quadratic, P<0.01) ADG and improved (quadratic, P<0.01) F/G, although the largest increases in ADG and F/G occurred as TID TSAA increased from 0.61 to 0.76%, with smaller improvements from 0.76 to 0.90%. Average daily gain and F/G values were plotted as the dependent variables in a regression analysis, with the TID lysine and TSAA concentrations on the Y axis. Regression analysis of the response surface resulted in an estimated TID TSAAto-lysine ratio range of approximately 55 to 56% for optimal ADG and F/G.

Is the total sulfur amino acid:lysine ratio for lactating sows greater than 50%? (2005)

A total of 75 lactating sows were used in a study to determine whether the ratio of total sulfur amino acid (TSAA) to lysine calculated from the NRC (1998) is adequate for lactating sows. Low and high sulfur amino acid diets were formulated to contain a (true ileal digestible (TID) TSAA content of 0.44 or 0.57%, respectively. Both experimental diets were based on corn and soybean meal and were formulated to contain 0.88% TID lysine (0.97% total lysine). Thus, the TID TSAA:lysine ratios were 50 and 65% for the two experimental diets, respectively. Both experimental diets contained 0.37% L-lysine HCl, with other amino acids (isoleucine, threonine, tryptophan, and valine) added to ensure that TSAA were the first limiting amino acids. Sows were farrowed in three farrowing groups and were randomly allotted to the dietary treatments on the basis of parity. The lactating sows fed the 0.57% T had greater ADFI than did sows fed the 0.44% TSAA diet (P<0.05). Sow weight loss was not affected by lactation treatment, but sows fed the diet with more TSAA had greater (P<0.02) litter weight gain, heavier (P<0.01) litter weaning weights, and heavier (P<0.06) individual pig weaning weight than did sows fed the 0.44% TSAA diet. These data indicate that the basal diet can be used in future experiments to titrate the TSAA requirement of the sow. Results also indicate that the TID TSAA requirement is greater than 0.44% and the TSAA:lysine ratio is greater than 50% for lactating sows. Because amino acid recommendations from the NRC (1998) suggest that the TID TSAA:lysine ratio is approximately 48%, more research is warranted to more adequately determine the TID TSAA:lysine ratio for lactating sows.; Swine Day, 2005, Kansas State University, Manhattan, KS, 2005

The optimal true-ileal-digestible lysine and total sulfur amino acid requirement for finishing pigs fed paylean® (2004)

A total of 1887 pigs (PIC 337 × C22; 213 lb initial BW) were used in a 28-d growth assay to simultaneously examine both the true-ileal-digestible (TID) lysine and TID total sulfur amino acid (TSAA) requirements. The objective was to determine the appropriate TID TSAA-to-lysine ratio in finishing pigs fed Paylean® (4.5 g/ton) to maximize growth performance and carcass composition. Four TID lysine (0.66. 0.79, 0.92, and 1.05%) and four TID TSAA (0.47, 0.52, 0.57, and 0.63%) concentrations were evaluated. The highest lysine and TSAA concentrations were combined in the same diet, and there were eleven or twelve replicate pens per treatment. The lysine treatments were formulated with a minimum TID TSAA to lysine ratio of 60%, and the TSAA diets were formulated with 1.05% TID lysine. No gender × treatment or treatment × week interactions were observed (P>0.13). Increasing TID lysine increased ADG (linear, P<0.01), with the greatest response at 0.92% TID lysine, but ADG (P>0.76) was not affected by increasing TID TSAA. This resulted in a TID TSAA-to-lysine ratio of not more than 51% for optimum ADG. Increasing TID lysine did not affect ADFI (P>0.60), but ADFI decreased (linear, P<0.04) with increasing TID TSAA. Increasing dietary TID lysine improved feed efficiency (F/G) (linear, P<0.01), and increasing TID TSAA tended to improve F/G (linear, P<0.09). Although the response was linear, the greatest improvement in F/G was observed as the TID TSAA increased from 0.47% to 0.52%, resulting in an optimum TID TSAA-to-lysine ratio of 57%. Regression analysis indicates that the maximum F/G response was obtained with a TID TSAA-to-lysine ratio of 58%. Increasing TID lysine had no effect on any carcass criteria (P>0.11), but increasing TID TSAA from 0.47 to 0.52% tended to improve fat-free lean (quadratic, P<0.10). No other carcass criteria were affected by increasing TID TSAA (P>0.10). In summary, a TID TSAA-to-lysine ratio of 58% optimizes growth performance of finishing pigs fed Paylean.; Swine Day, 2004, Kansas State University, Manhattan, KS, 2004

The optimal true-ileal-digestible lysine and total sulfur amino acid requirement for nursery pigs between 20 and 50 lb (2004)

The optimal true-ileal-digestible lysine and total sulfur amino acid requirement for nursery pigs between 20 and 50 lb (2004)

Regulation of Sulfur Amino Acid Metabolism in Men in Response to Changes in Sulfur Amino Acid Intakes

We showed previously that 64% of the total dietary sulfur amino acid (SAA) requirement could be supported by dietary cysteine (Cys). However, the observation of such a sparing effect may be affected by the dietary intakes of SAA provided. The aim of this study was to compare methionine (Met) metabolism and transsulfuration (TS) in five healthy men fed three different diets (in random order) for 3 d each, with varying combinations of Met and Cys: 24 mg Met/(kg. d) and no Cys (diet A); 13 mg Met/(kg. d) and 11 mg Cys/(kg. d) (diet B); and 5 mg Met/(kg. d) and 19 mg Cys/(kg. d) (diet C). On d 3, Met kinetics and TS were assessed using orally administered L-[1-(13)C, methyl-(2)H(3)]methionine. Met demethylation (transmethylation, TM) significantly decreased as the dietary Met to Cys ratio decreased. Met TS was significantly lower during diets B [2.8 +/- 0.4 micro mol/(kg. h)] and C [1.5 +/- 0.5 micro mol/(kg. h)] than during diet A [7.8 +/- 2.9 micro mol/(kg. h)] (P < 0.05). The results of the present study indicate that when the ratio of Met to Cys fed is typical of that found in major food proteins and total SAA are sufficient to meet requirements, TS is significantly reduced compared with the case in which SAA needs are supplied by Met alone. We conclude that Cys sparing occurs through an increase in the fraction of the homocysteine pool destined for RM relative to TS (RM:TS).

Total sulfur amino acid requirement in young men as determined by indicator amino acid oxidation with l-[1-13C]phenylalanine

Determining the sulfur amino acid (SAA) requirements of humans has remained elusive because of the complex nature of SAA metabolism. Current recommendations are based on nitrogen balance studies. The goal of the present study was to determine the methionine requirement of men fed a diet devoid of cysteine (total SAA requirement). Six men were randomly assigned to receive 6 graded intakes of methionine: 0, 6.5, 13.0, 19.5, 26.0, and 32.0 mg x kg(-1) x d(-1). The total SAA requirement was determined by measuring the oxidation of L-[1-13C]phenylalanine to 13CO2 (F(13)CO2)). The mean total SAA requirement was estimated with use of a linear regression crossover analysis, which identified a breakpoint of the F(13)CO2 response to methionine intake. On the basis of the mean measures of F(13)CO2, the mean requirement and population-safe intake (upper limit of the 95% CI) of total SAAs were found to be 12.6 and 21 mg x kg(-1) x d(-1), respectively. Although the mean SAA requirement is consistent with current guidelines for the total SAA intake, the population-safe intake is substantially higher than the currently recommended total SAA intake.

Estimation of the total sulfur amino acid requirement and the effect of betaine in diets deficient in total sulfur amino acids for the weanling pig.

Four experiments were conducted to determine whether betaine (BET) could replace dietary methionine (MET) in diets for weanling pigs. Pigs in each experiment were allotted to treatments on the basis of weight in a randomized complete block design. Each treatment was replicated four (Exp. 4), five (Exp. 1 and 2), or six (Exp. 3) times with five or six pigs per replicate. In Exp. 1, pigs were fed a diet formulated to be deficient in total sulfur amino acids (TSAA) (negative control; NC) or the NC + 0.05 or 0.10% MET or BET during Phase 1 and 0.035 or 0.07% MET or BET during Phase 2. Growth performance was not affected (P > 0.10) by dietary treatments, indicating that the diets were not deficient in TSAA. In Exp. 2, graded levels of TSAA (0.74, 0.79, 0.84, 0.89, or 0.94%) were fed. Overall ADG was increased (0 vs added MET, P < 0.07) in pigs fed TSAA levels of 0.79% or greater, but gain:feed was not affected (P > 0.10) by diet. Overall ADFI was increased (linear, P < 0.08) and plasma urea N (PUN) was decreased (quadratic, P < 0.01) as the level of TSAA was increased. Most of the change in ADG, PUN, and ADFI occurred between 0.74 and 0.84% TSAA. Thus, the 0.74% TSAA diet was used in Exp. 3 as the NC. In Exp. 3, the diets included the following: 1) NC, 2) NC + 0.05% MET, 3) NC + 0.10% MET, 4) NC + 0.039% BET, or 5) NC + 0.078% BET. The addition of MET resulted in increased (linear, P < 0.10) ADG, ADFI, and gain:feed, but MET decreased PUN (linear, P < 0.05). Daily gain, ADFI, and TSAA intake were not different (P > 0.10) between pigs fed 0.05% MET or 0.039% BET, but gain:feed was decreased (P < 0.01) in pigs fed 0.039% BET compared with pigs fed 0.05% MET. In Exp. 4, a 2 x 2 x 2 factorial arrangement of treatments was used (MET, 0 or 0.072%; cystine, 0 or 0.059%; or BET, 0 or 0.057%). Overall ADG and gain:feed were increased (P < 0.10) in pigs fed MET. The intake of TSAA was increased (P < 0.05), and PUN was decreased (P < 0.10) in pigs fed MET or cystine. Overall ADFI was increased in pigs fed BET or MET independently but not affected when BET and MET were fed together (BET x MET, P < 0.10). The addition of BET to TSAA-deficient diets resulted in increased ADG, which was due to an increase in ADFI (TSAA intake). Thus, BET did not spare MET in this experiment.

Dietary Sulfur Amino Acid Requirement of Juvenile Yellow Perch Fed the Maximum Cystine Replacement Value for Methionine

We conducted three separate experiments designed to determine the dietary methionine requirement, ability of cyst(e)ine to spare methionine, and the total sulfur amino acid requirement (TSAA) of juvenile yellow perch when fed the maximal amount of cyst(e)ine. The purified basal diet used in each experiment contained 33.6 g of crude protein/100 g diet and 12.0 g of lipid/100 g diet. In the first experiment,;>L-methionine was added to eight diets providing methionine concentrations ranging from 0.37 to 1.77 g/100 g diet in gradations of 0.2 g/100 g diet. Diets were fed for 12 wk to juvenile yellow perch initially weighing 4.7 g/fish. Broken-line analyses of weight gain and feed efficiency data indicated that the dietary methionine requirement was 1.0 g/100 g diet (3.1 g TSAA/100 g dietary protein) and 1.1 g/100 g diet (3.4 g TSAA/100 g dietary protein), respectively. In the second experiment, various ratios of L-cyst(e)ine and L-methionine were added to the basal diet and fed for 12 wk to determine the cyst(e)ine replacement value of yellow perch initially weighing 19.3 g/fish. Weight gain and feed efficiency (FE) data indicated that cyst(e)ine spared up to 51% of the methionine requirement. In the final experiment, graded levels of cyst(e)ine plus methionine in a ratio of 51:49 were added to the basal diet in gradations of 0.1 g/100 g diet (0.5 to 1.2 g TSAA/100 g diet) to determine the dietary total sulfur amino acid requirement. Diets were fed to satiation for 10 wk to fish initially weighing 8. 1 g. Broken-line analyses of weight gain, feed intake and FE data indicated that the dietary TSAA requirement was 0.85, 0.87 and 1.0 g of TSAA/100 g diet (2.5 to 3.0 g of TSAA/100 g of dietary protein), respectively. The majority of dietary TSAA requirements of fish are in the range of 2 to 4 g/100 g of dietary protein and are generally similar to those of both birds and swine, but lower than estimates for rodents.

Choline Is Required by Tilapia when Methionine Is Not in Excess

Choline is essential in diets fed to most young vertebrates, but previous studies did not confirm the essentiality of choline in diets fed to tilapia. Two experiments were conducted to evaluate the essentiality of dietary choline in such diets. The basal diet used in both experiments contained 32 g crude protein/100 g diet (10.1 g crude protein from casein and gelatin, and 21.9 g from a crystalline L-amino acid mixture). The total sulfur amino acid (TSAA) concentration of the basal diet was 0.28 g/100 g diet, Met:Cys 89:11. In Experiment 1, a 4x2 design was used in which crystalline L-methionine was added to the basal diet resulting in four levels of TSAA (0.28, 0.50, 0.75 or 1.0 g/100 g diet, Met:Cys 89:11, 94:6, 96:4, or 97:3, respectively). At each level of TSAA, diets also contained either 0 or 1 g choline/kg diet supplied as choline chloride. Weight gain, feed efficiency (FE) and serum methionine concentrations were significantly affected by dietary TSAA concentration, but not by dietary choline concentration or the interaction between TSAA and choline. Weight gain, feed efficiency and serum methionine concentrations indicated that the TSAA requirement was 0.5 g/100 g diet. In the second experiment, diets were formulated to contain either 0.28 or 0.5 g TSAA/100 g diet, Met:Cys 89:11 or 94:6, respectively, and graded levels of choline ranging from 1 to 4 g/kg diet in gradations of 1 g/kg. Dietary methionine significantly affected weight gain and FE, whereas dietary choline significantly affected weight gain, FE and survival, and the interaction of methionine and choline significantly affected weight gain. Fish fed diets containing 0.5 g TSAA/100 g diet and 3 g choline chloride/kg diet exhibited the highest weight gain, feed efficiency and survival. On the basis of these data, it seems clear that juvenile tilapia require choline in certain dietary formulations.

Sulphur amino acid requirement of juvenile Asian sea bass Lates calcarifer

The dietary requirement of juvenile Asian sea bass Lates calcarifer Bloch for total sulphur amino acids was studied. Fish (average initial weight of 2.59 ± 0.08 g) were reared in twelve 500 L fibreglass tanks provided with flow-through seawater at 26°C and salinity of 31 p.p.t. for 12 weeks. They were fed semi-purified test diets containing 6.2, 7.2, 8.1, 9.0, 10.8, or 12.6 g methionine kg−1 dry diet and a basal level of 3.1 g cystine kg−1 dry diet. The mean crude protein of the diets (containing defatted Peruvian fishmeal, squid meal, soybean meal, and free amino acid mixture to simulate the pattern of hydrolysed sea bass protein) was 46.02%. The crude fat content of the diets was 10.51% from a 1 : 1 mixture of cod liver oil and soybean oil. Survival was 100% in all treatments. On the basis of the growth response, the total sulphur amino acid requirement of juvenile Asian sea bass was estimated to be 13.4 g kg−1 dry diet (2.9% of protein). Fish fed low levels of l-methionine had significantly lower weight gains and feed efficiency ratios as well as slightly higher hepatosomatic indices. No nutritional deficiency signs were observed other than growth depression in fish fed on diets that were low in methionine. This information is valuable in further refinement of formulations of practical diets for the Asian sea bass.

Total sulphur amino acid requirement of the Indian major carp, Labeo rohita (Hamilton)

The quantitative dietary sulphur amino acid requirement of the Indian major carp, Labeo rohita (Hamilton), was determined by conducting a growth study. The experimental diets contained 400 g crude protein kg−1 from casein, gelatine and supplemental crystalline amino acids. Diets containing six graded levels of methionine (3.2, 6.5, 9.0, 11.5, 14 and 16.5 g kg−1) with a constant level of cystine (1.4 g kg−1) were formulated and fed to triplicate groups of Labeo rohita fingerlings twice a day to satiation for 60 days. The optimum dietary requirement for methionine was estimated using the break-point regression analysis at 11.5 g kg−1 of diet or 28.8 g kg−1 of dietary protein. Thus the total sulphur amino acid (Met + Cys) requirement was determined to be 12.9 g kg−1 of diet or 32.3 g kg−1 of protein. Higher survival, specific growth rate and food conversion efficiency values were observed for fish fed the diet containing optimum levels of sulphur amino acids.

Performance of Sunshine Bass Fed Soybean-Meal-Based Diets Supplemented with Different Methionine Compounds

Abstract Practical diets that contain high levels of plant proteins often require supplementation with methionine to satisfy the total sulfur amino acid requirements of animals. The present study was designed to evaluate L-methionine, DL-methionine, N-acetyl-DL-methionine (acetylmethionine), and DL-methionine hydroxy analog (MHA) as supplements in soybean-meal-based diets for sunshine bass, the hybrid of white bass Morone chrysops ♀ × striped bass M. saxatilis ♂. Five practical diets were formulated to contain crude protein at 40% of dry weight, with 75% of the protein provided by soybean meal and 25% provided by menhaden fish meal. The basal diet provided total sulfur amino acids from intact protein at approximately 1.0% of dry diet, and the test diets were supplemented with each of the methionine compounds at 0.3% dry weight on an equal-sulfur basis (except for an additional 25% for MHA). A control diet was formulated to contain 40% crude protein exclusively from menhaden fish meal. All experimental die...

Methionine requirement of juvenile tiger shrimp Penaeus monodon Fabricius

An 8-week feeding trial was conducted to determine the dietary requirement of postlarval Penaeus monodon for the sulfur-containing amino acid methionine. Shrimp postlarvae (mean weight 21 ± 0.3 mg) were reared in 40-1 fiberglass tanks in a flow-through seawater system. Test diets (37% protein and 360 kcal per 100 g diet) were formulated containing casein-gelatin as protein sources and supplemented with crystalline amino acids to simulate the amino acid pattern in shrimp tissue protein except methionine. The diets contained graded levels of methionine at a range of 0.72–1.12% of the diet or 2.0–3.0% of protein. In diet preparation, the crystalline amino acids were pre-coated with carboxymethylcellulose (CMC) to reduce leaching. Diets were further coated with CMC, cornstarch, and κ-carrageenan to improve water stability and the diet pH was kept at 7.0–7.2 by neutralization with 6N NaOH. Shrimp were fed the diets at 25–30% of their biomass thrice daily. At termination of the feeding experiment, various parameters including growth, survival, and feed conversion efficiency were determined and nutritional deficiency signs noted. The methionine requirement was determined from the relationship between weight gain and dietary methionine level using the broken-line regression method. The requirement of P. monodon postlarvae for methionine was 0.89% of the diet or 2.4% of protein. In a diet containing 0.41% cystine, the total sulfur amino acid requirement (methionine + cystine) would be 1.3% of the diet or 3.5% of protein. This requirement is slightly lower than the methionine level present in shrimp tissue protein.

The effects of protein levels on the total sulphur amino acid requirements of broilers during two growth periods

Studies on the effects of protein levels on the total sulphur amino acid (TSAA) requirements of chickens were conducted on the starter broilers by feeding four levels of crude protein (16, 18, 20 and 23%) at three levels of TSAA (0.83, 0.93 and 1.03%) and on the grower broilers by feeding three levels of crude protein (16, 18 and 20%) at three levels of TSAA (0.72, 0.79 and 0.86%). The metabolisable energy of the diets was maintained constant at 3,200 kcal/kg and the experiments were earned out for two growing periods: starter (0-3 wk) and grower (3-6 wk). The results showed that there were significant differences in body weight gain, feed intake and feed:gain ratio under different protein levels of the starters. Crude protein, ME and TSAA intake were significantly affected by increasing the CP levels. The TSAA requirement of the starter broilers is recommended at 0.93% and it is not influenced by different protein levels used in the experiment. For the grower period, body weight gain and feed:gain ratio improved significantly at higher protein diets. Birds fed higher protein diet consumed greater quantities of protein. Responses to TSAA supplementation for body weight gain, feed intake and feed:gain ratio were not significant. The present results showed that the TSAA level of 0.79 to 0.86% was required for grower diets and that the protein levels of the diet did not influence the the TSAA requirement.

Evaluation of the total sulfur amino acid requirement of finishing pigs (1996)

Evaluation of the total sulfur amino acid requirement of finishing pigs (1996)

Evaluation of the total sulfur amino acid requirement of finishing pigs (1996)

Evaluation of the total sulfur amino acid requirement of finishing pigs (1996)

Dietary total sulfur amino acid requirement for optimal growth performance and carcass characteristics in finishing gilts (1996)

Finishing gilts (initially 163 lb) were fed .58% total lysine (.50% apparent digestible) and total sulfur amino acid (TSAA) concentrations of .26, .285, .31, .335, and .36% (.225 to .325% apparent digestible). These values represent TSAA: lysine ratios of 45, 50, 55, 60, and 65%. Results suggest a linear decrease in ADG and ADFI along with poorer F/G with increasing TSAA levels. However, gilts fed .285% TSAA (50% of lysine) had the best ADG and F/G. No effect was observed on any carcass criteria. Based on the results of this study, the TSAA requirement is not greater than .285% total (.25% apparent digestible) or approximately50% of the lysine requirement.; Swine Day, Manhattan, KS, November 21, 1996

Dietary total sulfur amino acid requirement for optimal growth performance and carcass characteristics in finishing gilts (1996)

Dietary total sulfur amino acid requirement for optimal growth performance and carcass characteristics in finishing gilts (1996)