Limiting amino acids in low protein maize-soyabean meal diets fed to broiler chicks from 3 to 7 weeks of age

1. An experiment with separately housed male and female broiler chicks was carried out during the period of 3 to 7 weeks of age to determine the limiting amino acids (AA) in a low protein maize-soyabean meal diet. Chicks were fed on diets containing 170, 180, 190 and 200 g crude protein (CP)/kg with or without combined additions of L-threonine (Thr), L-tryptophan (Trp) and L-arginine (Arg) to those in the 180, 190 or 200 g CP/kg diets and a 170 g CP/kg diet with or without combined additions of Thr, Trp, Arg, L-isoleucine (Ile), L-leucine (Leu) and L-valine (Val) to those in the 190 g CP/kg diet. The diets were iso-energetic and contained the same concentrations of lysine (Lys) and sulphur-containing amino acids. 2. Decreasing the dietary CP had a significantly negative effect on performance. 3. No significant effects on performance were found when diets with 180 and 190 g CP/kg were supplemented with Thr, Trp and Arg to those in the 200 g CP/kg diet. 4. There were no significant differences in performance between the groups fed on the diets with 170, 180 and 190 g CP/kg when the 170 and 180 g CP/kg diets were supplemented with Thr, Trp and Arg to those in the 190 g CP/kg diet.(ABSTRACT TRUNCATED AT 250 WORDS)     

Digestibility of amino acids in corn, corn coproducts, and bakery meal fed to growing pigs

The objectives of this experiment were to determine the apparent ileal digestibility and the standardized ileal digestibility (SID) of CP and AA in bakery meal, corn gluten meal, corn gluten feed, corn germ meal, and hominy feed and to compare these values with the apparent ileal digestibility and SID of CP and AA in corn and distillers dried grains with solubles (DDGS). Eight growing barrows (initial BW: 82.5 ± 5.5 kg) were randomly allotted to an 8 × 8 Latin square design with 8 diets and 8 periods. Diets contained corn, DDGS, bakery meal, corn gluten meal, corn gluten feed, corn germ meal, or hominy feed as the sole source of protein and AA. An N-free diet was used to measure basal endogenous losses of AA and protein. Pigs were fed experimental diets for eight 7-d periods, with ileal digesta being collected on d 6 and 7 of each period. Results indicated that the SID of Lys in corn gluten meal (78.7%) was greater (P < 0.01) than in DDGS, bakery meal, corn germ meal, and hominy feed (46.0, 48.4, 68.4, and 58.8%, respectively). The SID of all indispensable AA except Arg, Leu, and Met in bakery meal were not different from those in DDGS. The SID of Arg, His, Leu, and Met in corn gluten feed were less (P < 0.01) than in corn, but the SID of all other indispensable AA in corn gluten feed were not different from those in corn. However, for most indispensable AA, the SID in corn gluten feed was not different from the SID in DDGS. The SID of all indispensable AA in corn germ meal, except Arg, His, Leu, and Met, were not different from the SID in corn. Likewise, the SID of all indispensable AA in corn germ meal, except Arg and Leu, were not different from those in DDGS. The SID of Ile, Met, Phe, and Val in hominy feed were less (P < 0.01) than in corn, but the SID of the remaining indispensable AA in hominy feed were not different from the SID of indispensable AA in corn. All indispensable AA in hominy feed also had SID values that were not different from the SID values of AA in DDGS, except for Arg and Lys, which had greater (P < 0.01) SID than in DDGS. In conclusion, bakery meal had SID values of most AA that were less than in corn, but corn gluten meal had SID values for most AA that were greater than the SID of AA in corn, bakery meal, and corn coproducts.     

Intestinal supply of amino acids in sheep fed alkaline hydrogen peroxide-treated wheat straw-based diets supplemented with soybean meal or combinations of corn gluten meal and blood meal

The intestinal supply of amino acids (AA) in sheep fed alkaline hydrogen peroxide-treated wheat straw (AHPWS)-based diets supplemented with soybean meal (SBM) or corn grain plus combinations of corn gluten meal (CGM) and blood meal (BM) was measured in a 5 X 5 latin square. Sheep (avg wt 45 kg) with ruminal, duodenal and ileal cannulas were fed diets containing 65% AHPWS supplemented with the following protein sources: soybean meal (SBM), corn gluten meal (CGM), blood meal (BM), 2/3 CGM:1/3 BM and 1/3 CGM:2/3 BM. Total nitrogen (N) flow at the duodenum was not affected (P greater than .05) by protein source. Flows of bacterial N and AA increased (P less than .05) and flows of nonbacterial N and AA decreased (P less than .05) when wethers were fed SBM vs corn plus other protein sources. When diets contained SBM, quantities of total AA at the duodenum were lower (P less than .05) and the profile of AA supplied to the intestine was altered substantially. Total flows of AA at the duodenum and total quantities of AA disappearing from the small intestine were similar (P greater than .05) for all diets containing BM and CGM, but flows and disappearance of valine, histidine, lysine and arginine increased linearly (P less than .05), whereas flows and disappearance of leucine, isoleucine and methionine decreased linearly (P less than .05) as BM replaced CGM in the diets. Results suggest that quantities of individual AA flowing to the duodenum and disappearing from the intestine of wethers fed AHPWS-based diets can be altered by source of dietary protein. Furthermore, feeding protein sources resistant to ruminal degradation in combination may improve the profile of AA supplied to the intestine.     

Alternate day supplementation of corn stalk diets with soybean meal or corn gluten meal fed to ruminants.

Four experiments were conducted to determine the effect of adding corn gluten mean (CGM) or soybean meal (SBM) at 24- or 48-h intervals to diets based on corn stalks. In each experiment corn stalks was the primary diet ingredient fed to wethers or steers. Monensin was also fed to determine whether its effects on ruminal fermentation would improve the efficiency of N utilization under these conditions. Evaluation criteria included ruminal fermentation characteristics, DM intake and utilization, N balance in sheep, and steer feedlot performance. Ruminal ammonia nitrogen (NH3 N) concentrations measured over time were higher (P < .05) when diets contained SBM. Diet did not influence (P > .10) total VFA concentrations in ruminal fluid. Differences in diurnal shifts in ruminal NH3 N and total VFA due to protein source resulted in diet x hour interactions (P < .05). Dry matter intake response to protein source and frequency of supplement feeding was variable. Dry matter digestibility and nitrogen digestibility were not affected (P > .10) by protein source or feeding interval. The 48-h interval feeding of CGM was favorable compared with 24-h interval feeding (P < .05). The opposite response occurred with SBM, resulting in a diet x feeding interval interaction (P < .05). Nitrogen retention was greater (P < .05) when CGM was fed and with alternate day feeding. Diets that contained CGM supported higher (P < .05) ADG and gain/feed than diets that contained SBM when fed to steer calves. Alternate day feeding of supplements that contained monensin was detrimental to steer performance under the conditions of these experiments. Corn gluten meal is an effective substitute for SBM when alternate day protein supplementation is practiced.     

Evaluation of soybean meal, corn gluten meal, blood meal and fish meal as sources of nitrogen and amino acids disappearing from the small intestine of steers

The value of soybean meal (SBM), corn gluten meal (CGM), blood meal (BM) and fish meal (FM) in supplying N and amino acids (AA) escaping ruminal microbial degradation and disappearing from the small intestine (SI) was studied in steers using a regression approach. Replacement of corn starch in diets with protein sources resulted in decreases (P less than .05) in efficiency of microbial protein synthesis. Ruminal ammonia-N (NH3-N) had the greatest increase (P less than .05) when SBM was fed; BM supplementation resulted in only nonsignificant increases in ruminal NH3-N (P greater than .05). Soybean meal had the lowest proportion of N escaping ruminal degradation (.21). Corn gluten meal-N (.86) and BM-N (.92) escaped ruminal degradation to the greatest extent, and FM-N was intermediate (.68). Protein sources followed similar trends in providing absorbable nonbacterial N to the SI. Thirteen (+/- 6.2) percent of SBM-N was absorbed from the SI; 69 (+/- 6.2), 68 (+/- 9.1) and 50 (+/- 10.1)% of CGM-N, BM-N and FM-N, respectively, were absorbed from the SI. Values for ruminal escape and SI availability for individual and total AA are presented. Of the essential AA (EAA), threonine, valine and isoleucine were more resistant to ruminal degradation; methionine, cysteine, histidine and arginine were more extensively degraded than the total AA supply. Of the EAA escaping ruminal degradation, cysteine, histidine and threonine tended to be less digestible, whereas arginine was more digestible in the SI than the total AA supply.     

Digestion of soybean meal and canola meal protein and amino acids in the digestive tract of young ruminants

Eight male Holstein calves (body weight 68 +/- 5 kg; age 75 +/- 6 d), each with a permanent re-entrant pancreatic cannula and T-type ileal and duodenal cannulas, were used in a crossover design with four animals per group to determine amino acid kinetics and digestibilities in the digestive tract of calves fed soybean meal (SBM) and canola meal (CM) protein. The SBM and CM diets were fed twice daily at a level of 900 g at each feeding time (air-dry basis). With the exception of methionine, crude protein and amino acid flows at the proximal duodenum, expressed as a percentage of intake, were not influenced by dietary protein source. Apparent ileal and total tract digestibilities of CP and amino acids were reduced (P less than .05) by feeding CM compared to SBM, but apparent ileal digestibility of methionine was not affected by dietary protein source. Except for methionine, net disappearance of all amino acids in the small intestine, relative to the amount fed, was higher for the SBM diet than for the CM diet. Net disappearance or synthesis of amino acids in the large intestine were not affected by dietary protein source. Similarly, dietary protein source did not affect (P greater than .05) the secretion of pancreatic juice or concentrations of protein, chymotrypsin and trypsin in pancreatic juice. Soybean meal protein has higher ileal and total gastrointestinal tract digestibility than CM protein for young, growing calves.     

凡纳滨对虾对7种蛋白原料的蛋白质和氨基酸的消化率

采用三氧化二铬(Cr2O3)作为指示剂,以70%基础饲料和30%待测饲料蛋白原料组成试验饲料,测定了体重(2.08±0.01)g的凡纳滨对虾(Penaeus vannamei)对花生粕、玉米蛋白粉、羽毛粉、肠膜蛋白粉、鸡肉粉、肉骨粉和喷雾干燥血粉粗蛋白和氨基酸的表观消化率。试验采用循环过滤水系统养殖,每个饲料组设3个重复,每个重复30尾虾,试验结果表明,凡纳滨对虾对7种不同饲料蛋白源的粗蛋白表观消化率为53.04%～86.38%,其大小顺序依次为:肠膜蛋白粉(86.38%)花生粕(79.82%)喷雾干燥血粉(79.62%)鸡肉粉(72.55%)肉骨粉(71.29%)玉米蛋白粉(63.46%)羽毛粉(53.04%)。凡纳滨对虾对7种不同饲料蛋白源的氨基酸平均表观消化率主要变化趋势与对蛋白质表观消化率的变化基本一致,其大小顺序依次为:肠膜蛋白粉(88.81%)喷雾干燥血粉(84.76%)花生粕(80.19%)鸡肉粉(71.06%)肉骨粉(70.74%)玉米蛋白粉(59.46%)羽毛粉(44.71%)。上述试验结果为研究适于凡纳滨对虾营养需要的全价高效人工配合饲料提供了参考依据。     

Limiting amino acids for growing lambs fed a diet low in ruminally undegradable protein

Ruminally cannulated Rambouillet wether lambs were used in three 6 x 6 Latin square experiments (n = 6/experiment) to determine which essential AA limit N retention. Lambs (BW = 36.9 +/- 1.9 kg for Exp. 1, 35.1 +/- 1.4 kg for Exp. 2, and 46.0 +/- 1.3 kg for Exp. 3) were housed in metabolism crates and limit-fed (DMI = approx. 1.8% of BW daily) twice daily a soybean hull-based diet low in ruminally undegradable protein. Treatments for Exp. 1 were continuous abomasal infusions of a solution (500 mL/d) containing 1) no AA (CON), 2) a mixture of 10 essential AA and 2 nonessential AA (10EAA), 3) 10EAA with Met removed, 4) 10EAA with Lys removed, 5) 10EAA with His removed, and 6) 10EAA with Thr removed. Treatments for Exp. 2 were abomasal infusions of 1) CON, 2) 10EAA, 3) 10EAA with Leu, Ile, and Val removed (-BCAA), 4) 10EAA with Arg removed, 5) 10EAA with Phe removed, and 6) 10EAA with Trp removed. Treatments for Exp. 3 were abomasal infusions of 1) CON, 2) 10EAA, 3) -BCAA, 4) 10EAA with Leu removed, 5) 10EAA with Ile removed, and 6) 10EAA with Val removed. All lambs received continuous infusions of acetate and propionate into the rumen and dextrose into the abomasum to supply additional energy. Periods were 7 d: 3 d for adaptation to abomasally infused treatments and 4 d for fecal and urinary collections. Blood samples were collected 3 h after feeding on d 7. In all 3 experiments, N retention was greater (P < 0.10) for lambs receiving 10EAA vs. CON, demonstrating that the basal AA supply from CON was limiting. Removal of each of the essential AA from 10EAA decreased (P < 0.10) their concentrations in plasma (except for Trp), indicating that 10EAA supplied these AA in excess of the animal's requirement. In Exp. 1, N retention (g/d) decreased (P < 0.10) in response to the removal of Met and Thr, but was not affected by removal of Lys and His from 10EAA. In Exp. 2, N retention decreased (P < 0.10) in response to removal of all 3 branched-chain AA, Arg, and Trp, whereas the removal of Phe from 10EAA did not affect N retention. In Exp. 3, N retention decreased (P < 0.10) in response to removal of branched-chain AA and Val, but was not affected by the omission of Leu and Ile from 10EAA. The results of this research demonstrated that Met, Thr, Arg, Trp, and Val limited N retention of lambs fed a diet low in ruminally undegradable protein.     

Limiting amino acids in an 11% crude protein corn-soybean meal diet for growing pigs

Three experiments were conducted to test the hypothesis that methionine, isoleucine, valine or nitrogen either singly or in combination are limiting in an 11% crude protein, lysine-tryptophan-threonine-supplemented, corn-soybean meal diet for growing pigs. A 16% crude protein diet was used as a positive control in each experiment and all amino acid additions were made, at a minimum, to equal requirements. Average initial weights were 21.3 kg, 23.0 kg and 19.1 kg in Exp. 1, 2 and 3, respectively. The experiments averaged 4 wk in duration. In Exp. 1 and 2, neither the addition of glutamic acid as a source of nitrogen, nor methionine to the 11% diet resulted in any improvement (P greater than .20) in rate or efficiency of growth. Addition of the combination of isoleucine and valine to the 11% diet resulted in an increase (P less than .05) in both growth rate and feed efficiency to a level not different (P greater than .20) from that of the pigs consuming the positive control diet. The addition of valine to the 11% crude protein diet with supplemental lysine, tryptophan and threonine (Exp. 3) caused an improvement in daily gain (P less than .05) but not feed efficiency (P greater than .10). Isoleucine addition tended to reduce pig performance. The results of these experiments suggest that an 11% crude protein, corn-soybean meal diet fortified with lysine, tryptophan and threonine is not limiting in sulfur amino acids or nitrogen. Valine may be the only limiting amino acid.     

The effects of supplementary bacterial phytase on dietary energy and total tract amino acid digestibility when fed to young chickens

1. Four diets were offered to broiler chickens from 7 to 17 d of age; these included a phosphorus-adequate positive control (PC) (4·7 g/kg available P), a sub-optimal P negative control (NC, 2·5 g/kg available P) with (500 and 12500 FTU/kg) and without phytase. Dietary apparent metabolisable energy (AME), dietary net energy for production (NEp), the efficiency of AME retention (Kre), heat production and total tract amino acid digestibility coefficients were determined. The determination of NEp involved a comparative slaughter technique in which growing chickens were fed the experimental diets ad libitum. 2. Feed intake, weight gain and feed conversion efficiency increased significantly in a dose dependent manner in response to dietary phytase activity. Overall, the NEp of the phytase supplemented diets significantly improved by approximately 15·6% compared with the negative control, while dietary AME was unaffected. Although phytase did not affect AME, the large increase in the NEp demonstrated that dietary phytases improves energy utilisation, i.e. diverting more energy, not accounted for in the AME procedure, for production. This is largely a result of the stimulatory effect that phytase has on feed intake rather than on digestibility of the diet. 3. Overall, the diet supplemented with 12500 FTU had 6·4% significant improvement in total tract digestibility coefficients of the total amino acids compared with the negative control. With regard to individual amino acids, the impact of phytase was far more pronounced for threonine, an important component of the gastrointestinal mucin, than for other amino acids. 4. Dietary NEp was more highly correlated with performance criteria than dietary AME and seems to be a more sensitive way to evaluate broiler response to phytase supplementation.     

Individual variation in the content of free amino acids observed in the blood and muscle of chicks fed a single meal daily

1. Fifty broiler chicks in individual cages, were fed on a balanced diet ad libitum until 10 d old and then given a single meal daily. Blood and pectoral muscle samples were taken from each. Free aspartic acid, threonine, serine, glutamic acid, glycine, alanine, valine, cystine, isoleucine, leucine, phenylalanine, lysine and arginine were determined.

2. Free amino acid concentrations varied greatly between birds. Values for the coefficient of variation ranged from 0.21 for serine in both tissues to 0.571 and 0.749 for valine and lysine in blood and muscle respectively.

3. Many correlations for pairs of amino acids did not seem related to the body weight of chicks.     

Absence of limiting amino acids in calves fed a corn and soybean meal diet past three months of age

We conducted three nitrogen balance trials using Holstein bull calves older than 16 wk (Trial 1; n = 8), 13 wk (Trial 2; n = 6), and 15 wk of age (Trial 3; n = 9) in a 4 x 4 (Trial 1) or 3 x 3 Latin square design (Trials 2 and 3) to identify limiting amino acids for a corn and soybean meal diet. All calves were trained to maintain reflex closure of the reticular groove after weaning at 5 wk of age. The basal diet was fed daily at 20 or 27 g/kg BW (Trial 1) and at 20 g/kg BW (Trials 2 and 3). The lower feeding level resulted in reduced urinary excretion of purine derivatives, suggesting reduced synthesis of ruminal microbial protein (Trial 1). In Trials 1 and 2, administration of DL-methionine plus L-lysine monohydrochloride through the reticular groove did not increase N retention compared with the supplement of isonitrogenous L-glutamine at either level of intake. In Trial 3, administration of either casein or isonitrogenous monosodium glutamate increased N retention to a similar extent above that observed with a N-free supplement. Results suggested that no specific amino acids were limiting for the corn-soybean meal diet. Administration of methionine plus lysine resulted in a remarkable increase in plasma methionine (Trials 1 and 2), especially at the lower intake level (Trial 1), and a decrease in plasma branched-chain amino acids at either intake level. Glutamine supplementation did not increase plasma branched-chain amino acids compared with the supplementation of diammonium citrate (Trial 2).     

Intrinsic phytase in hybrid rye increases the digestibility of phosphorus in corn and soybean meal in diets fed to growing pigs

An experiment was conducted to test the hypothesis that inclusion of hybrid rye in diets containing corn and soybean meal (SBM) without or with microbial phytase improves the apparent total tract digestibility (ATTD) and the standardized total tract digestibility (STTD) of P because of the intrinsic phytase activity in hybrid rye. Forty-eight growing barrows (initial body weight: 39.5 ± 7.7 kg) were allotted to six diets. A basal diet containing corn and SBM; a rye-based diet; and a diet containing corn, SBM, and rye were formulated. Each diet was formulated without and with microbial phytase (500 units/kg of diet) for a total of six diets. Fecal samples were collected for 4 d following a 5-d adaptation period according to the marker-to-marker procedure. Results indicated that no interactions between diets and concentration of phytase were observed for any of the response criteria measured. The ATTD and STTD of P and the ATTD of Ca differed (P < 0.05) among diets, but regardless of diet, the concentration of P in feces was reduced (P < 0.05) by adding microbial phytase to the diets. As a consequence, microbial phytase increased (P < 0.05) ATTD and STTD of P, and the ATTD of Ca was also increased (P < 0.05) by the use of microbial phytase. Measured values for the ATTD and STTD of P in the diets containing corn, SBM, and hybrid rye without or with phytase were greater (P < 0.05) than values that were predicted based on the ATTD and STTD of P for the corn–SBM and the hybrid rye diet. The observation that STTD predicted from the individual ingredients underestimated the STTD of P in the mixed diet indicates that the intrinsic phytase in hybrid rye resulted in increased digestibility of the P in the corn and SBM included in the corn–SBM–hybrid rye diet. In conclusion, microbial phytase increased the ATTD and STTD of P and the ATTD of Ca regardless of feed ingredients used in diets fed to pigs. In addition, the intrinsic phytase from hybrid rye increased the ATTD and STTD of P in corn and SBM.     

发酵豆粕替代鱼粉及添加包膜氨基酸、植酸酶对花鲈幼鱼生长性能及养殖水质的影响

试验旨在研究不同比例发酵豆粕替代鱼粉及添加包膜氨基酸、植酸酶对花鲈生长性能和养殖水质的影响。选取初始体重为(13.00±0.02)g的花鲈400尾,随机分为5组,每组4个重复,每个重复20尾鱼。在42 d的饲养期间分别投喂5种试验饲料,即高鱼粉组(36%鱼粉+8%发酵豆粕)、中鱼粉组(31%鱼粉+20%发酵豆粕)、包膜氨基酸组(31%鱼粉+20%发酵豆粕)、植酸酶组(31%鱼粉+20%发酵豆粕)和低鱼粉组(26%鱼粉+32%发酵豆粕),分别记为G0、G1、G2、G3和G4。试验结果显示,与G0组相比,G1、G2组和G3组花鲈的末均重、增重率和特定生长率显著升高(P0.05),饲料系数显著降低(P0.05),G4组与G0组无显著差异(P0.05)。与G1组相比,G2组饲料系数显著下降(P0.05)。G3组中饲料系数低于G1组,但差异不显著(P0.05)。与G0组相比,G4组中花鲈的肝体比显著下降(P0.05)。各组间成活率和肥满度无显著差异(P0.05)。各组间花鲈全鱼体成分及水体pH值、溶氧量和总氮差异不显著(P0.05)。第14 d之后,G2组和G3组亚硝酸盐氮含量显著低于G0组(P0.05)。第21 d之后,G2、G3组和G4组水体总磷含量显著低于G0组(P0.05),其中第28 d,G3组比G0组降低26.92%。第28 d之后,G0组氨氮含量显著高于其它组(P0.05)。发酵豆粕替代鱼粉及添加包膜氨基酸和植酸酶可提高花鲈的生长性能,降低养殖水质中氨氮、亚硝酸盐氮和磷的排放,改善花鲈养殖水质。     

玉米麸质饲料在肉仔鸡中的能量和回肠氨基酸表观消化率的研究

<正>玉米麸质饲料又称为玉米蛋白饲料(corngluten feed)或简称玉米麸料,是玉米以湿磨法提取油脂和淀粉的过程中产生的工业副产品,其主要成分是由玉米     

Comparison of corn gluten meal and meat meal as a protein source in dry foods formulated for cats

OBJECTIVE: To compare the nutritional value of corn gluten meal (CGM) and meat meal (MM) as a dietary source of protein in dry food formulated for adult cats. ANIMALS: 8 healthy adult cats (4 males and 4 females). PROCEDURE: Diets containing CGM or MM as the main protein source were each fed for a 3-week period in a crossover study. Digestibility and nutritional balance experiments were conducted during the last 7 days of each period. Furthermore, freshly voided urine was obtained to measure urinary pH, struvite crystals, and sediment concentrations. RESULTS: Daily food intake and dry-matter digestibility were significantly higher for the MM diet. Fecal moisture content also was higher for the MM diet. Apparent nitrogen (N) absorption and N retention were higher for the MM diet, even when values were expressed as a percentage to account for differences in N intake. Urinary pH, struvite activity product, number of struvite crystals in urine, and urinary sediment concentrations were not different between diets. Retention of calcium, phosphorus, and magnesium was lower for the CGM diet, and cats lost body calcium and magnesium when fed the CGM diet. CONCLUSIONS AND CLINICAL RELEVANCE: Meat meal was superior to CGM as a protein source in dry foods formulated for cats, because dry-matter digestibility and N utilization were higher for the MM diet. In addition, net loss of body calcium and magnesium for the CGM diet suggests that mineral requirements increase when CGM is used as a protein source.