Crystalline Lysine Research Articles

Tail Muscle Free Amino Acid Concentration of Pacific White Shrimp, Litopenaeus vannamei, Fed Diets Containing Protein‐bound versus Crystalline Amino Acids

Abstract Tail muscle tissue free amino acids (FAA) concentration is reported for subadult (4.3 g) Litopenaeus vannamei fed diets containing only protein‐bound amino acids, crystalline lysine as a supplement to protein‐bound lysine, and only crystalline amino acids (CAA). FAA were determined in shrimp at 0.00, 0.25, 0.5, 1, 2, 4, and 8 h postfeeding. Highest total tissue concentrations of essential amino acids and individual amino acids were typically observed 4 h postfeeding for shrimp fed intact and crystalline lysine‐supplemented feeds. Those shrimp offered diets containing only CAA showed no tissue maxima. Similar uptake patterns for lysine shown by shrimp fed the intact and crystalline lysine‐supplemented diet indicate the potential use of small amounts of crystalline lysine in shrimp feeds.

Effect of Season on Growth Performance of Finishing Pigs fed Low-Protein, Amino Acid Supplemented Diets

Myer, R.O., Brendemuhl, J.H. and Bucklin, R.A. 2008. Effect of season on growth performance of finishing pigs fed low-protein, amino acid supplemented diets. J. Appl. Anim. Res., 34: 1–8. A two year study was conducted to evaluate the effects of diet (low-protein diets supplemented with crystalline amino acids (aa) vs. high-protein, non aa supplemented control diets) and season/rearing environment (hot, humid summer vs. cool fall/winter) on growth performance and carcass lean content of finishing pigs (52 to 110 kg). For each year, two trials, each with 84 pigs, were conducted. Outside daily high and low temperatures (C) and RH (%), respectively, averaged 26, 21 and 81; 26, 20 and 83; 14, 7 and 80; and 10, 3 and77for yr 1 and 2 summer and y r 1 and 2 fall I winter, respectively. Diets were maize and soybean meal based (3.3 meal ME/kg). The low-protein (LP) diets were four percentage units lower in crude protein (CP) than the corresponding control diets; crystalline lysine, threonine, tryptophan and methionine were added to the LP diets to meet the pigs' requirements (NRC, 1998). For each trial, split sex Finisher I (52 to 82 kg), and Finisher II (82 to 110 kg), diets were fed. Each dietary treatment was fed to six pens of seven pigs for each trial. Water sprinklers were used during warm weather (>25C). Floor space was 0.7m2 per pig. Pigs reared during the summer grew 9% slower than pigs reared during the fall/winter (0.88 vs. 0.97 kg/d, P<0.001); average daily feed intake (ADF) and feed conversion efficiency (F/G) were also affected by season (P<0.001). Pigs fed the LP + aa diets averaged 3% lower ADG than pigs fed the control diets (0.91 vs. 0.94 kg; P<0.01); ADF and F/G were not affected (P>0.10). The decrease in ADG was more pronounced during the summer vs. fall/winter (6% vs. 1%; season × diet, p = 0.02). The decrease noted occurred only during Finisher II (0.91 vs. 0.84 kg/d; P<0.001; FI, 0.97 vs. 0.98). Estimated carcass lean was not affected by diet or season (mean = 51% fat free). The feeding of a LP + aa diet used appears to be of no particular benefit on improving pig growth performance from 52 to 110 kg under hot and humid conditions.

The effect of controlled fermentation on the fate of synthetic lysine in liquid diets for pigs

Crystalline lysine is frequently added to pig diets to provide the correct amino acid balance. Recent studies have shown that free lysine can be lost when liquid pig feed is fermented with lactic acid bacteria (LAB). The metabolism of lysine was examined, over 72 h, in uninoculated liquid feed (Control) and in liquid feed inoculated with lactic acid bacteria (LAB) ( Lactobacillus plantarum and Pediococcus acidilactici); or Escherichia coli and combinations of LAB and E. coli. In the Control and the fermentations that included E. coli, lysine was rapidly metabolised, with ca. 90% degraded in 21 h. The production of cadaverine accounted for ca. half of the lysine lost. There was no loss of lysine in the LAB fermentations and no cadaverine was produced. Combining E. coli and LAB resulted in a loss of ca. 20% lysine in the first 7 h with no further metabolism thereafter. Cadaverine produced in these fermentations accounted for all of the lysine lost. The rate of lysine metabolism was inhibited by the increase in lactic acid present in the fermentations. Fermenting E. coli and LAB with the addition of 50 mM lactic acid at 0 h resulted in the lysine levels remaining unaltered throughout the fermentation period. These results imply that the loss of lysine from fermented liquid pig diets is due to the metabolism of lysine by E. coli before they are eliminated from the diet by the increasing acidity resulting from LAB fermentation.

Quantitative dietary lysine requirement of juvenile grass carp Ctenopharyngodon idella

A 90-day feeding trail was conducted to determine the dietary lysine requirement of juvenile grass carp using six isonitrogenous and isoenergetic diets (38% protein, 14 MJ digestible energy kg − 1 ) with wheat gluten–casein–gelatin as protein resource supplemented with six graded levels of crystalline lysine (from 0.69% to 3.08% of dry diet). Crystalline amino acid mixtures were supplemented to simulate the amino acid pattern found in the whole-body protein of grass carp except for lysine. Each diet was randomly assigned to triplicate groups of 20 fish each (3.15 ± 0.01 g, mean ± S.E.M.) and fish were fed five times daily at 2.5% body weight per day. No mortality or nutritional deficiency signs were observed except for growth depression in fish fed the diet with low content of lysine. Weight gain (WG), specific growth rate (SGR), feed efficiency (FE), protein efficiency ratio, nutrient retention, proximate body composition, morphometry and hematology were significantly ( P < 0.05) affected by the dietary lysine concentrations. WG, SGR and FE were significantly higher in fish fed diet containing lysine 2.18% of the diet. Second-degree polynomial regression analysis of the WG and FE data indicated that the minimum recommended dietary lysine requirement for optimal growth of juvenile grass carp was 2.24% of the dry diet, corresponding to 5.89% of dietary protein. While the lysine availability (92.37%) of the protein sources was considered, the optimal lysine requirement of juvenile grass carp was calculated to be 2.07% of the diet, corresponding to 5.44% of the dietary protein. Additionally, the estimated requirements for the other essential amino acids were calculated from A/ E ratios of whole-body amino acid profile based on the lysine requirement determined from the present experiment.

Bioavailability of phosphorus in meat and bone meal for swine1,2

Meat and bone meal (MBM), when supplemented with tryptophan, is an excellent protein source for pigs. It is also a rich source of Ca and P, but some research has suggested that the bioavailability of P is variable. Experiment 1 further examined the bioavailability of P in MBM. The MBM was obtained directly from a plant and was processed to pass through a 10-mesh screen. It contained 50.7% CP, 2.26% lysine, 10.0% Ca, and 5.0% P (air-dry basis). Individually penned pigs (n = 35; 17 kg initial BW) were fed (ad libitum basis) a low-P, corn-soybean meal-basal diet (0.95% lysine, 0.70% Ca, 0.34% P; as-fed basis) or the basal with graded levels of added P (0.067, 0.133, 0.200%) from monosodium phosphate (MSP) or MBM for 40 d. The Ca level was 0.70% in all diets. Diets were fortified with salt, vitamins, and trace minerals. At termination, the third and fourth metacarpals and metatarsals and femurs were removed from all pigs. Growth rate and feed:gain improved linearly (P < 0.01) with P addition, regardless of source, whereas ADFI was unaffected (P = 0.20). Bone strength and ash increased linearly (P < 0.01) with increasing level of P from either source. The main effect of P source (MSP vs. MBM) was not significant, except for the greater femur strength (P < 0.05) in the pigs fed the MSP-supplemented diets. Femur and metacarpal/metatarsal strength and metacarpals ash (grams) were regressed on grams of added P consumed for each P source, with the basal included in both regressions. Based on slope ratios (MSP considered as 100%), the relative bioavailability of P in MBM averaged 87% when the regression lines were forced through a common intercept and 95% when unforced. In Exp. 2, 100 pigs were fed fortified corn-soybean meal or corn-soybean meal-MBM diets from 45 to 110 kg BW to evaluate MBM as the sole source of supplemental P. The MBM (54% CP, 2.3% lysine, 9.2% Ca, 4.4% P; air-dry basis) was substituted for corn and soybean meal on a lysine basis, and crystalline lysine was added to all diets at 0.15%. Tryptophan was included in diets containing MBM. Treatments were arranged in a 2 x 2 factorial with P source (dicalcium phosphate or MBM) and P level as the two factors. The two levels of P and Ca were at the NRC requirement or the NRC level plus 0.10% additional P and Ca. Performance, carcass traits, and bone strength were not affected by source of P and Ca, but bone strength was greater (P < 0.01) at the higher P and Ca level. These results indicate that the bioavailability of P in MBM, relative to that in MSP, is high (approximately 91%) for growing pigs, and MBM can serve as the sole source of supplemental P and Ca for finishing pigs.

Crystalline Amino Acid Supplementation of Grain Sorghum-Based Low Protein Diets for Growing-Finishing Pigs

Myer, R.O. and Gorbet, D.W. 2004. Crystalline amino acid supplementation of grain sorghum-based low protein diets for growing-finishing pigs. J. Appl. Anim. Res., 25: 85–90. A study was conducted to evaluate the effectiveness of crystalline lysine, threonine, methionine and tryptophan supplementation of grain sorghum based, low protein diets for growing and finishing pigs (from 31 to 114 kg avg. body wt.). Three similar trials, each with 60 crossbred pigs were done and each involved a comparison of nutritionally adequate grain sorghum-based diets formulated with 1) soybean meal (47%) as the supplemental source of amino acids (control) or with 2) L-lysine HCl, L-threonine, DL-methionine and L-tryptophan plus enough soybean meal to meet the requirements of the other amino acids. Overall, dietary treatment had no effect (P>0.10) on average daily gain, average daily feed intake, feed conversion efficiency, average loin area, backfat thickness or estimated carcass lean percentage. Overall average daily lean gain, however, was lower (P<0.10) for pigs fed the low protein, amino acid supplemented diets compared to pigs fed the control diet. Results indicated that the diet crude protein concentration can be reduced substantially upon amino acid supplementation with no detrimental effect on pig growth performance, however, there was some evidence of decreased lean gain.

Difference in rates of net portal absorption between crystalline and protein-bound lysine and threonine in growing pigs fed once daily1

Net portal absorption of AA during the 6-h postprandial period was measured in eight gilts (48.5 ± 1.6 kg BW) in a crossover design. The pigs had chronic catheters placed in the portal vein, carotid artery, and ileal vein, and were trained to consume 1.2 kg of a standard grower diet once daily. Blood samples were taken every 30 min for 4 h and then hourly until 6 h after feeding. The first set of blood samples was taken after pigs were fed a meal of the test 16% CP corn–soybean meal diet (16% CP) or the test 12% CP corn–soybean meal diet supplemented with crystalline lysine, threonine, and tryptophan (12% CP + AA) to equal the three AA levels in the 16% CP diet. Pigs were then fed the standard diet for 2 d. Following that, blood samples were again taken after the pigs were fed a meal of the test diet that was not given to them at the first sampling period. Net portal AA absorption was calculated by multiplying porto-arterial plasma AA concentration difference by portal vein plasma flow rate (PVPF), estimated by an indicator-dilution technique employing p-aminohippuric acid as the indicator infused into the ileal vein. Plasma concentrations of lysine and threonine of pigs were affected by the diet × time interaction (P < 0.01). Portal and arterial plasma lysine and threonine concentrations in pigs attained the maximal level by 1 h postprandial when the 12% CP + AA diet was fed, but reached the peak level at 2.5 h postprandial when the 16% CP diet was given. The PVPF of pigs over the 6 h postprandial was less (P < 0.01) when the 12% CP + AA diet was given than when the 16% CP diet was fed. Net portal absorptions of lysine and threonine also were affected (P < 0.05) by time × diet interaction. The peak portal absorption of both lysine and threonine in pigs appeared at 0.5 h postprandial when the 12% CP + AA diet was given, but at 2.5 h postprandial with the feeding of the 16% CP diet. The early appearance of peak portal absorption of lysine and threonine from feeding the 12% CP + AA compared with the 16% CP diet indicates that crystalline lysine and threonine are absorbed more rapidly than protein-bound lysine and threonine in pigs fed once daily.

Difference in rates of net portal absorption between crystalline and protein-bound lysine and threonine in growing pigs fed once daily.

Net portal absorption of AA during the 6-h postprandial period was measured in eight gilts (48.5 +/- 1.6 kg BW) in a crossover design. The pigs had chronic catheters placed in the portal vein, carotid artery, and ileal vein, and were trained to consume 1.2 kg of a standard grower diet once daily. Blood samples were taken every 30 min for 4 h and then hourly until 6 h after feeding. The first set of blood samples was taken after pigs were fed a meal of the test 16% CP corn-soybean meal diet (16% CP) or the test 12% CP corn-soybean meal diet supplemented with crystalline lysine, threonine, and tryptophan (12% CP + AA) to equal the three AA levels in the 16% CP diet. Pigs were then fed the standard diet for 2 d. Following that, blood samples were again taken after the pigs were fed a meal of the test diet that was not given to them at the first sampling period. Net portal AA absorption was calculated by multiplying porto-arterial plasma AA concentration difference by portal vein plasma flow rate (PVPF), estimated by an indicator-dilution technique employing p-aminohippuric acid as the indicator infused into the ileal vein. Plasma concentrations of lysine and threonine of pigs were affected by the diet x time interaction (P < 0.01). Portal and arterial plasma lysine and threonine concentrations in pigs attained the maximal level by 1 h postprandial when the 12% CP + AA diet was fed, but reached the peak level at 2.5 h postprandial when the 16% CP diet was given. The PVPF of pigs over the 6 h postprandial was less (P < 0.01) when the 12% CP + AA diet was given than when the 16% CP diet was fed. Net portal absorptions of lysine and threonine also were affected (P < 0.05) by time x diet interaction. The peak portal absorption of both lysine and threonine in pigs appeared at 0.5 h postprandial when the 12% CP + AA diet was given, but at 2.5 h postprandial with the feeding of the 16% CP diet. The early appearance of peak portal absorption of lysine and threonine from feeding the 12% CP + AA compared with the 16% CP diet indicates that crystalline lysine and threonine are absorbed more rapidly than protein-bound lysine and threonine in pigs fed once daily.

Effects of increasing crystalline lysine and dietary fat on finishing pig growth performance (2003)

A total of 1,024 barrows (each initially 157 lb, PIC L337 x C22) were used in a 28-d study to evaluate the effects of increased crystalline amino acids (none versus 4.5 lb/ton of L-lysine HCl plus L-threonine to maintain the proper ratio relative to lysine) and added dietary fat (none, 3 or 6% choice white grease) on finishing pig growth performance. All experimental diets were formulated with a constant true ileal digestible lysine:ME ratio based on NRC, (1998) ingredient values for ME. A minimum true ileal digestible threonine:lysine ratio of 68% and a minimum true ileal digestible methionine + cystine:lysine ratio of 55% were used in diet formulation. There was no synthetic amino acid by added fat interactions. Increasing added fat increased (linear, P<0.01) ADG and improved F/G. Replacing soybean meal with crystalline amino acids had no affect on growth performance. This indicates that the increased amounts of L-lysine HCl and added L-threonine were used as efficiently as amino acids provided from soybean meal. Neither adding fat nor crystalline lysine affected feed cost/lb of gain using current ingredient prices. However, margin over feed cost (profit) increased as added fat increased because of the increased pig weight due to improved ADG. In summary, these results confirm the improved ADG and F/G when adding fat to finishing pig diets. Furthermore, 4.5 lb/ton of Llysine HCl and L-threonine can effectively replace soybean meal without negatively affecting growth performance of pigs from 157 to 217 lb.; Swine Day, 2003, Kansas State University, Manhattan, KS, 2003

Effects of increasing crystalline lysine with other amino acids on growth performance of 85- to 135-lb gilts (2003)

A total of 1,134 gilts (each initially 85 lb, PIC L337 x C22) was used in a 28-d experiment to evaluate the effects of replacing soybean meal with up to 8 lb/ton of crystalline Llysine HCl with other crystalline amino acids on growth performance. Gilts were randomly allotted to one of six experimental diets. Diets were corn-soybean meal-based with 3% added fat. Diets included a negative control containing 3 lb/ton of L-lysine HCl and formulated to 0.90% true ileal digestible lysine. Two additional diets were formulated with 3 lb/ton Llysine to 1.0% true ileal digestible lysine but with or without crystalline threonine and methionine to compare threonine to lysine ratios of 60 versus 65% and methionine & cystine (TSAA) ratios of 55 vs. 60%. The three remaining diets contained 6, 7, or 8 lb/ton of Llysine HCl with crystalline threonine and methionine to provide the same ratios relative to lysine of 65 and 60%, respectively.

Contribution of intestinal microbial lysine to lysine homeostasis is reduced in minipigs fed a wheat gluten–based diet

We previously reported microbial lysine contribution to plasma lysine homeostasis in humans with an adequate lysine intake. We sought to explore whether the low lysine intake from a wheat gluten-based diet is balanced by enhanced microbial lysine contribution in a pig model. Twenty miniature pigs (minipigs) fitted with ileo-ileal cannulas were fed 2 wheat gluten-based diets. One diet provided 2.7 g lysine/kg diet (WG diet) and one diet was supplemented with crystalline lysine to provide 6.6 g lysine/kg diet (WG+Lys diet). Both diets were fed for 10 or 100 d (n = 5 per group): 10WG+Lys, 10WG, 100WG+Lys, and 100WG diets. Ileal microbial lysine, which we considered to be the precursor pool for absorption, was labeled by oral administration of (15)NH(4)Cl for the final 10 d. On days 10 and 100, a 10-h fast-fed tracer protocol with [1-(13)C]lysine was performed. Lysine rates of appearance decreased by 25% with the WG diet in the fed state but increased by 50% with the WG+Lys diet in the fasted state (P < 0.05). Daily gross microbial lysine contribution was lower (P < 0.05) with the WG diet (205.3 micro mol. kg(-) (1). d(-)(1)) than with the WG+Lys diet (370.7 micro mol. kg(-) (1). d(-)(1)), irrespective of the adaptation period and was similar to the ileal lysine loss with the WG diet. In the WG groups, incorporation of microbial lysine increased in the duodenum and liver (P < 0.05) but not in whole-body and muscle proteins. Minipigs fed the WG diet did not adapt by showing an enhanced absorption of microbial lysine to the extrasplanchnic tissues, presumably because microbial lysine continues to be used for splanchnic protein synthesis.

Body composition and tissue accretion rates of barrows fed corn-soybean meal diets or low-protein, amino acid-supplemented diets at different feeding levels.

Two experiments, each with 39 high-lean-gain potential barrows, were conducted to evaluate the organ weights, body chemical composition, and tissue accretion rates of pigs fed corn-soybean meal diets (CONTROL) and low-protein diets supplemented with crystalline lysine, threonine, tryptophan, and methionine either on an ideal protein basis (IDEAL) or in a pattern similar to that of the control diet (AACON). Amino acids were added on a true ileally digestible basis. The initial and final BW were, respectively, 31.5 and 82.3 kg in Exp. 1 and 32.7 and 57.1 kg in Exp. 2, and pigs were fed for 55 and 27 d in Exp. 1 and 2, respectively. In Exp. 1, the CONTROL and IDEAL diets were offered on an ad libitum basis, or by feeding 90 or 80% of ad libitum intake. In Exp. 2, the CONTROL, IDEAL, and AACON diets were offered on an ad libitum basis, or by feeding 80% of the ad libitum intake. Three pigs were killed at the start of the experiments and three from each treatment were killed at the end of each experiment to determine body chemical composition. In both trials, the whole-body protein concentration (g/kg) and the accretion rates of protein (g/d) were greater (P < 0.05) for pigs fed the CONTROL than for pigs fed the IDEAL and AACON diets. In Exp. 1, pigs fed the CONTROL diet had a trend (P < 0.10) for greater water and lower lipid concentration and had greater (P < 0.05) water and ash accretion rates. Whole-body protein concentration was greatest (P < 0.05) in pigs fed at 80% of ad libitum, but protein, water, and ash accretion rates were greatest (P < 0.05) in pigs allowed ad libitum access to feed. In summary, pigs fed the IDEAL and the AACON diets had less protein in the body and lower protein accretion rates than pigs fed the CONTROL diet. It seems that reductions in protein deposition in pigs fed the IDEAL and AACON diets may have been due to a deficiency of one or more essential amino acids or possibly to increases in the NE for metabolic processes leading to increases in adipose tissue deposition.

Growth performance, diet apparent digestibility, and plasma metabolite concentrations of barrows fed corn-soybean meal diets or low-protein, amino acid-supplemented diets at different feeding level.

Two experiments, each with 36 barrows with high-lean-gain potential, were conducted to evaluate apparent nutrient digestibilities and performance and plasma metabolites of pigs fed corn-soybean meal diets (CONTROL) and low-protein diets. The low-protein diets were supplemented with crystalline lysine, threonine, tryptophan, and methionine either on an ideal protein basis (IDEAL) or in a pattern similar to that of the control diet (AACON). Amino acids were added on a true ileally digestible basis. The initial and final BW were, respectively, 31.5 and 82.3 kg in Exp. 1 and 32.7 and 57.1 kg in Exp. 2. In Exp. 1, the CONTROL and IDEAL diets were offered on an ad libitum basis or by feeding 90 or 80% of ad libitum intake. Pigs were fed for 55 d. In Exp. 2, the CONTROL, IDEAL, and AACON diets were offered on an ad libitum basis or by feeding 80% of the ad libitum intake. Pigs were fed for 27 d. Pigs fed the CONTROL diet had greater (P < 0.05) ADG and feed efficiency (G/F) than pigs fed the IDEAL (Exp. 1 and 2) and AACON diets (Exp. 2). As the level of feed intake decreased, ADG decreased (P < 0.05), but G/F tended to improve (P < 0.10) for pigs fed 90% of ad libitum in Exp. 1 and for pigs fed 80% of ad libitum in Exp. 2. In Exp. 1, the apparent total tract digestibilities of DM and energy were greater (P < 0.01) for pigs fed the IDEAL diet than for pigs fed the CONTROL diet. In Exp. 2, the apparent total tract digestibility of protein was greatest in pigs fed the CONTROL diet (P < 0.05) and was greater (P < 0.05) in pigs fed the AACON diet than in pigs fed the IDEAL diet. Plasma urea concentrations were lower in pigs fed the IDEAL diet than in pigs fed the CONTROL diet, regardless of feeding level. For pigs fed the CONTROL diet, plasma urea concentrations were lower when feed intake was 80% of ad libitum (diet level, P < 0.01). In summary, pigs fed the IDEAL and the AACON diets gained less and had lower plasma urea concentrations than pigs fed the CONTROL diet. Based on these data, it seems that the growth potential of pigs fed the IDEAL and AACON diets may have been limited by a deficiency of lysine, threonine, and(or) tryptophan and that the amino acid pattern(s) used was not ideal for these pigs.

Effects of physical properties of diets on evacuation time of digesta and plasma free amino acid patterns in yellowtail

SUMMARY: The periodical changes of feed digesta contents in the digestive tracts and plasma free amino acid levels of yellowtail, Seriola quinqueradiata (average weight 690 g) were investigated at 0, 3, 6, 12, 18, 24, 30, and 48 h after feeding on three different types of diets. The diets were: (i) extruded pellets prepared using a large-sized twin screw extruder (SDP); (ii) pellets processed using a small-sized twin screw extruder (EP); and (iii) single moist pellets (SMP). Three types of experimental fish meal diets were formulated so as to have an almost similar ingredient composition, and were supplemented with crystalline methionine, lysine, and tryptophan. Digesta contents in the stomach of fish fed the SDP diet during the experimental period were highest, whereas fish fed the SMP diet were lowest, and the stomach digesta evacuation time was different for the different types of diets. This might be caused by the differences in the chemical and physical properties of the diets. The evacuation times of the feed digesta contents of the stomach influence those of the intestine. Three crystalline amino acids added to the diets seemed to be absorbed effectively into blood plasma immediately after feed intake irrespective of the diet types. Periodical changes in the plasma levels of methionine seemed to be linked to the feed digesta contents of the stomach. Therefore, it is suggested that utilization of supplemented methionine might be affected by diet characteristics which, in turn, influence the stomach digesta evacuation times.

Comparisons of lysine bioavailability in spray-dried blood meal, blood cells, and crystalline lysine in nursery pigs (2000)

Three hundred thirty-three nursery pigs (initially 23.7 lb) were used in a 21-d growth assay to determine the lysine bioavailability of spray-dried blood meal, blood cells, and crystalline lysine on growth performance. Regardless of lysine source, ADG improved linearly as dietary lysine increased. However, pigs fed diets containing blood cells gained faster then those fed diets with spraydried blood meal. Pigs fed diets containing crystalline lysine and blood cells had greater ADFI then pigs fed spray-dried blood meal. Feed efficiency improved by 11.6, 13.6, and 12.7% with increasing amounts of L-lysine HCl, spray-dried blood meal, and blood cells, respectively. If L-lysine has a lysine bioavailability of 100%, the lysine bioavailabilities of spray-dried blood meal and blood cells, as determined by a sloperatio, were 103 and 102%, respectively.; Swine Day, Manhattan, KS, November 16, 2000

Effect of room temperature and dietary amino acid concentration on performance of lactating sows. NCR-89 Committee on Swine Management.

Mixed-parity sows (n = 267) from five research stations were used to investigate whether a reduction of excess dietary amino acids would improve feed intake and performance of lactating sows experiencing heat stress. Experimental treatments included effects of room temperature (warm or hot) and diet (adequate protein [AP] or low protein [LP]). The corn-soybean meal AP diet was formulated to contain 16.5% CP, .8% lysine, and .67% digestible lysine. The LP diet was formulated to contain 13.7% CP, .76% lysine, and .66% digestible lysine using corn, soybean meal, and synthetic lysine. Feed intake during gestation was standardized at 1.8 kg x sow(-1) x d(-1). At parturition, litter size was adjusted to no fewer than nine pigs. Mean high temperature in the warm and hot rooms was 20.4 and 29.2 degrees C and mean low temperature was 17.7 and 27.1 degrees C, respectively. The hot environment reduced (P < .01) feed intake of sows (4.19 vs 6.38 kg/d) during lactation, weaning weight of sows (176.2 vs 193.6 kg), percentage of sows displaying estrus (79.2 vs 93.4%) by d 15 postweaning, and litter growth rate (1.74 vs 2.11 kg/d) and increased (P < .01) respiration rate of sows on d 10 postpartum (71.9 vs 36.5 breaths/min) compared with the warm environment. Litter size and backfat loss of sows were not affected by treatments. No significant diet x room temperature interactions were observed for voluntary feed intake, body weight loss, backfat loss, or respiration rate of sows. Litter growth rate was depressed by feeding the LP diet in the warm room but was improved by feeding the LP diet in the hot room (warm-AP, 2.17; warm-LP, 2.05; hot-AP, 1.71; hot-LP, 1.77 kg/d; P < .05). Reduction of dietary crude protein combined with supplementation of crystalline lysine to reduce concentrations of excess dietary amino acids did not significantly reduce heat stress of sows, but it did support slight improvements in weight gain of litters nursing heat-stressed sows.

Effects of crystalline lysine, threonine and tryptophan supplementation of diets containing reduced protein levels on performance of growing pigs

Effects of crystalline lysine, threonine and tryptophan supplementation of diets containing reduced protein levels on performance of growing pigs

Nutritional control of amino acid supply to the mammary gland during lactation in the pig.

The paucity of data relating to lactation physiology of the sow has frustrated researchers in estimating nutrient needs for production and mammary maintenance functions. The nutritional control of amino acid supply for milk synthesis is influenced by factors that have yet to be measured, such as blood flow and amino acid contribution from the body protein pool. The interaction or role of hormones such as insulin, glucagon or prolactin in amino acid dynamics and inter-organ exchange during lactation in the sow, are not well understood. The discrepancy existing between milk and mammary amino acid uptake profiles relative to lysine may be indicative of mammary metabolism and possibly maintenance requirements for specific amino acids. Hence, amino acid metabolism in the mammary gland, regardless of arterial blood substrate supply, may play an important role in a factorial approach to determining requirements. Mammary amino acid uptake ratios rather than milk amino acid ratios should provide a better tool to estimate amino acid requirements relative to lysine. Although lysine has typically been limiting in maize-soyabean-meal-based diets fed to lactating sows, current production trends are bringing a new dimension to the formulation of lactating-sow diets. Other amino acids may become limiting if dietary crystalline lysine is added without concern for the whole essential amino acid profile. Formulations based on an ideal amino acid profile for the lactating sow will, therefore, become critical.

Tryptophan needs of lactating sows fed diets supplemented with crystalline lysine.

Large White x Landrace primiparous and multiparous sows (n = 115) were used to evaluate the tryptophan needs of lactating sows fed diets supplemented with crystalline lysine to contain .75% lysine. Sows were fed 1.8 kg of their allotted diets from d 110 of gestation until parturition and then were allowed ad libitum access to diets analyzed to contain either .12 (n = 58) or .17% (n = 57) tryptophan during a 21-d lactation. Diets were created by crystalline tryptophan and lysine additions to a corn-soybean meal basal diet that contained .12% tryptophan. Tryptophan level in the lactation diet did not affect number or weight of pigs at 21 d (P > .10). Sows fed .17% tryptophan were heavier at d 21 of lactation than those fed .12% tryptophan (P = .09) due to less weight loss during the 21-d lactation (P = .09). Feed intake was greater (P < .05) for sows fed .17% tryptophan than for sows fed .12% tryptophan. A reference diet analyzed to contain .11% tryptophan and .63% lysine was fed to an additional 11 sows only as a baseline for measuring plasma urea nitrogen and amino acids. Plasma tryptophan concentrations were higher (P < .05) for sows fed .17% tryptophan than for sows not fed added L-tryptophan. Among sows fed the low-tryptophan diets, sows fed the reference diet (.60% lysine) had higher (P < .05) plasma phenylalanine and valine concentrations than sows fed .75% lysine. Diet did not affect plasma concentrations of any other essential amino acid (P > .10). Plasma urea N levels were lower (P = .11) for sows fed the diet supplemented with tryptophan. Lactating sows allowed ad libitum access to diets containing .75% lysine benefited from higher feed intake and lower weight loss when dietary tryptophan levels were increased from .12 to .17%.

Crystalline lysine and threonine supplementation of soft red winter wheat or triticale, low-protein diets for growing-finishing swine.

Five trials, with five treatments each, involving a total of 240 pigs were conducted to evaluate the effectiveness of supplementation of soft red winter wheat- or triticale-based diets with crystalline lysine and threonine for growing and finishing pigs (25 to 110 kg). Within each trial, wheat- or triticale-based diets were supplemented with soybean meal to meet the requirement of the first- (lysine) or third- (isoleucine/methionine + cystine) limiting amino acid. Diets formulated to the third-limiting amino acid also were supplemented with feed grade L-lysine. HCl and L-threonine to meet the requirements of the first- and second-limiting amino acids. A cornsoybean meal diet was included in each trial as a positive control treatment resulting in the five dietary treatments. Three different crop years of soft red winter wheat and triticale were utilized. Three of the trials, conducted in successive years with each using a different crop year of grain, were done at Marianna, and the other two, conducted in successive years using yr 1 and 2 crops, respectively, were done at Gainesville. In all trials, growing diets (.82% lysine) were fed from 29 (Marianna) or 25 kg (Gainesville) to 55 kg average BW and finishing diets (.64% lysine) to 110 or 100 kg. Over the three crop years, the wheat and triticale averaged 11.3 and 11.0% crude protein, .36 and .38% lysine, and .36 and .37% threonine, respectively. Overall, at either location, growth rate and carcass lean content were not affected by grain source (P > .10). At Marianna, gain:feed was 2 to 3% lower for pigs fed the triticale diets than for pigs fed wheat (P = .15) or corn (P < .10); gain:feed was not affected by grain source at Gainesville (P > .10). At both locations, substantial replacement of soybean meal protein with crystalline lysine and threonine did not affect pig growth or carcass lean content (P > .10), even when the diet contained very little or no soybean meal as occurred for finishing pigs (55 to 110 kg) fed diets containing triticale.