Methionine requirement of pigs between 5 and 20 kilograms body weight.

Four nursery experiments were conducted using a methionine (Met)-deficient feather meal-corn-soybean meal-dried whey basal diet (20% CP; 3,250 kcal of ME/kg, .11% choline, .19% Met, 1.00% cystine) supplemented with lysine, tryptophan, and histidine to determine the Met requirement of 5- to 10- and 10- to 20-kg pigs. Based on a true Met digestibility value of 81.6% estimated by a pig ileal digestibility assay, the Met-deficient basal diet contained .155% of digestible Met. A preliminary experiment (Exp. 1) indicated that pigs fed the Met-deficient basal diet when fortified adequately with Met could produce weight gains similar to those of pigs fed a 20% CP practical corn-soybean meal-dried whey diet. In Exp. 2 and 3, crossbred pigs weighing 5.8 kg initially were fed diets containing graded levels of digestible Met between .195 and .355%. Average daily gain increased quadratically (P less than .05) as the level of Met increased. When the data of Exp. 2 and 3 were examined together, the digestible Met requirement of 5- to 10-kg pigs was estimated to be .255% of the diet. In Exp. 4 and 5, crossbred pigs averaging 10 kg were fed digestible Met concentrations ranging from .155 to .315%. Average daily gain increased quadratically (P less than .05). The digestible Met requirement of 10- to 20-kg pigs was estimated at .255% for maximal weight gain, which was similar to that of 5- to 10-kg pigs. Assuming an 89% digestibility of Met in practical corn-soybean meal diets, the total Met level needed in practice would be .29%.(ABSTRACT TRUNCATED AT 250 WORDS)     

Apparent digestibility of nitrogen and amino acids in protein feedstuffs by growing pigs

Eight digestion trials were conducted with pigs fitted with ileal T-cannulas to determine the apparent digestibilities of N and amino acids in common protein feedstuffs. Trial-to-trial variation was minimal as determined by the variation in digestibilities for soybean meal, which was evaluated in each trial. Apparent digestibilities varied widely; ileal N digestibility ranged from 88 to 63%, and ileal lysine digestibility ranged from 93 to 40%. In general, ring-dried blood meal, corn gluten meal, Menhaden fish meal, poultry-by-product meal and extruded whole soybeans were the most digestible, followed by canola meal, sunflower meal, peanut meal and meat and bone meal. Cottonseed meal and feather meal were the least digestible. Mean values for each feedstuff agree well with published data. Variation in digestibilities among samples of the same feedstuff was greater for the meat and bone meals. Regression of ileal essential amino acid digestibilities on ileal and fecal N digestibility indicated that amino acid digestibilities can be predicted more precisely from ileal N digestibility than from fecal N digestibility. However, neither ileal nor fecal N digestibility could be used with a high degree of certainty to predict ileal amino acid digestibilities.     

Nutritional value of quality protein maize for starter and finisher swine.

Growth trials with starter (n = 120, 6.8 kg initially, 28 d of age, Exp. 1) and finisher (n = 70, 59 kg initially, Exp. 2) pigs were conducted to compare quality protein maize (QPM, .40% lysine) and normal corn (.31% lysine) in simple corn-based diets containing the same levels of soybean meal. In Exp. 1, pig performance was similar (P greater than .10) on all diets, regardless of the level of soybean meal, suggesting that QPM and normal corn have similar feeding value in lysine-adequate (.99 to 1.11%) diets. In Exp. 2, less soybean meal was needed in QPM than in normal corn diets to maximize performance; increasing soybean meal from 10.8 to 13.8% improved rate (P less than .05) and efficiency (P less than .01) of gain of pigs fed normal corn diets but had no effect on performance of pigs fed QPM diets. A QPM-based diet containing 6% soybean meal and supplemental lysine and tryptophan failed to maximize feed efficiency, but growth rate was equal to that obtained on the normal corn diet with 13.8% soybean meal. The apparent fecal digestibility of GE and ileal digestibility of N were similar for QPM and normal corn, but apparent ileal digestibility of most essential amino acids was slightly higher for QPM (Exp. 3). Experiment 4 compared apparent digestibilities of QPM, conventional opaque-2 corn and two high-protein corns. Digestibilities differed (P less than .05) among the corns, but the absolute differences were small and were likely due to differences in amino acid content of the corns.(ABSTRACT TRUNCATED AT 250 WORDS)     

使用猪T型瘘管法测定饲料原料氨基酸回肠末端表观消化率

使用 8头T型瘘管猪测定了 4种饲料原料的猪回肠末端氨基酸表观消化率。结果说明玉米和豆粕的氨基酸回肠末端表观消化率与最近的文献报道值较为一致 ,羽毛粉的氨基酸表观消化率有一定的趋势 ,乳清粉的氨基酸表观消化率与中国饲料数据库的推荐值较为吻合。这些数据可以为我国的氨基酸消化率数据库提供参考 ,并且可以作为以可消化氨基酸为基础配制日粮时的依据     

Effect of body weight on phosphorus digestibility and efficacy of a microbial phytase in young pigs.

The effect of body weight on P digestibility and on efficacy of supplemental Aspergillus niger phytase was studied in two experiments with young growing pigs. Excreta were collected quantitatively. All diets contained 2.0 g digestible P per kg dry matter at a maximum and renal P excretion never exceeded 15 mg/d. When dietary P mainly originated from monocalcium-phosphate, both P digestibility and Ca net absorption linearly increased by 3.6 and 5.6 percentage units, respectively, when BW increased from 15 to 35 kg. With a similar range in BW, P digestibility and Ca net absorption were unaffected by BW when P mainly originated from maize, barley and soybean meal. In both types of diet, crude protein digestibility increased with increasing body weight, whereas organic matter digestibility was effected by BW only in the diet containing maize, barley and soybean meal. Phytase (400 U/kg) almost doubled P digestibility when supplemented to a diet with P mainly originating from maize, soybean meal and barley. This effect of phytase supplementation was equal in pigs at 15.7 kg BW (33 vs. 55%) and at 39.1 kg BW (32 vs. 56%). Digestibility of any organic fraction was unaffected by supplemental phytase. With regard to on-farm conditions, it appears eligible from this results to apply digestibility coefficients for P determined in growing-finishing pigs for piglets as well.     

Methionine requirement of the finishing pig

Two pig experiments were conducted using a methionine (Met)-deficient feather meal-corn-soybean meal basal diet (13% CP; 3,400 kcal ME/kg diet, .126% Met, 456% cystine) supplemented with an amino acid mixture (lysine, tryptophan, histidine, threonine and phenylalanine) to determine the Met requirement of finishing pigs between 50 and 80 kg live weight. Using young chicks in a Met bioavailability growth assay and cecectomized adult cockerels in a Met digestibility assay, the Met-deficient basal diet was found to contain .115% bioavailable and .110% digestible Met. These results gave a bioavailability estimate (relative to DL-Met set at 100%) of 91.3 +/- 2.5% and a true digestibility estimate of 87.0 +/- 2.2% for Met in the basal pig diet. In Exp. 1, 21 crossbred pigs averaging 61 kg initially were individually fed diets containing .115, .165 or .215% bioavailable Met for 21 d. Average daily gain and gain:feed ratio increased quadratically (P less than .05) as level of Met increased. In Exp. 2, 30 crossbred pigs averaging 53 kg were individually fed diets containing .115, .135, .155, .175 or .195% bioavailable Met for 27 d. Daily gain and gain;feed ratio responded linearly (P less than .01) as Met level increased. Based on the results of Exp. 2, the bioavailable Met requirement of finishing pigs in the weight range 50 to 80 kg was estimated to be .182% of the diet. Assuming an 88% bioavailability of Met in commercial diets based on corn and soybean meal, the total Met level needed in practice would be .207%. If 55% of the finishing pig's sulfur amino acid need can be furnished by cystine, the total sulfur amino acid requirement would be .45% of the diet.     

Digestible and metabolizable energy concentrations and amino acid digestibility of dried yeast and soybean meal for growing pigs

Energy values and amino acid (AA) digestibility of dried yeast (DY) and soybean meal (SBM) were determined in 2 experiments with growing pigs. Experiment 1 was conducted to determine the digestible energy (DE) and metabolizable energy (ME) in DY and SBM. Thirty barrows with a mean initial body weight (BW) of 20.6 kg (SD = 1.04) were assigned to 5 dietary treatments in a randomized complete block design with period and BW as blocking factors. A reference diet was prepared with corn, canola meal, and soybean oil as energy-contributing ingredients. Four additional diets were prepared by adding 5% and 10% DY or SBM at the expense of energy-contributing ingredients in the reference diet. The ratio of corn, canola meal, and soybean oil was kept consistent across the experimental diets. Each experimental period consisted of 5-d adaptation and 5-d quantitative collection of feces and urine. Test ingredient-associated DE or ME intake (kcal/d) was regressed against test ingredient intake [kg dry matter (DM)/d] to estimate the DE or ME in test ingredients as the slope of linear regression model. The DE in DY was estimated at 3,933 kcal/kg DM, which was not different from the estimated DE in SBM at 4,020 kcal/kg DM. Similarly, there was no difference between DY and SBM in the estimated ME (3,431 and 3,756 kcal/kg DM, respectively). Experiment 2 was conducted to determine the standardized ileal digestibility (SID) of AA in DY and SBM. Twenty-one barrows with a mean initial BW of 20.0 kg (SD = 1.31) were surgically fitted with T-cannulas at the distal ileum and assigned to 3 dietary treatments in a randomized complete block design with BW as a blocking factor. Two semi-purified diets containing DY or SBM as the sole nitrogen source and one nitrogen-free diet (NFD) were prepared. The NFD was used to estimate the basal ileal endogenous losses of CP and AA. Pigs were fed the 3 diets for 5 d as adaptation, followed by 2 d of feeding with ileal digesta collection. The SID of AA, except Gly and Pro, in DY was less (P < 0.05) than in SBM. The SID of indispensable AA in DY ranged from 64.1% for Thr to 85.2% for Arg, and those in SBM ranged from 83.9% for Thr to 91.8% for Arg. In conclusion, energy values of DY are not different from those of SBM, whereas AA in DY is less digestible than in SBM. The estimated DE and ME as well as the SID of AA in DY and SBM can be used in diet formulation for growing pigs using these ingredients.     

浓缩脱酚棉籽蛋白生长猪消化能评定及其对仔猪生长性能、血清生化指标和养分表观消化率的影响

本研究旨在通过猪消化代谢试验测定浓缩脱酚棉籽蛋白(CDCP)生长猪消化能,同时研究其对仔猪生长性能、血清生化指标和养分表观消化率的影响.试验选取65日龄、体重(38.80±2.60)kg的"杜×(长×大)"健康阉公猪8头,随机分成2组(每组4个重复,每个重复1头猪),分别饲喂基础饲粮和试验饲粮(80％基础饲粮+20％C...     

Energy concentration and phosphorus digestibility in whey powder, whey permeate, and low-ash whey permeate fed to weanling pigs

Two experiments were conducted to determine DE and ME, the apparent total tract digestibility (ATTD) of P, and the standardized total tract digestibility (STTD) of P in whey powder (3,646 kcal/kg), whey permeate (3,426 kcal/kg), and low-ash whey permeate (3,657 kcal/kg) fed to weanling pigs. The DE and ME in the 3 whey products were determined using 32 barrows (9.2 ± 0.4 kg of BW). A basal diet based on corn, soybean meal, and fish meal and 3 diets containing 70% of the basal diet and 30% of each whey product were prepared. Each diet was fed to 8 pigs that were housed individually in metabolism cages. The total collection method was used for fecal and urine collections with 5-d adaptation and 5-d collection periods, and the difference procedure was used to calculate DE and ME in the 3 whey products. The concentrations of DE in whey powder and low-ash whey permeate were greater (P < 0.001) than in whey permeate (3,646 and 3,683 vs. 3,253 kcal/kg of DM). The concentrations of ME in whey powder and low-ash whey permeate were also greater (P < 0.001) than in whey permeate (3,462 and 3,593 vs. 3,081 kcal/kg of DM). The ATTD and STTD of P in the 3 whey products were determined using 32 barrows (11.0 ± 0.81 kg of BW). Three cornstarch-sucrose-based diets containing 30% of each whey product as the sole source of P were prepared. A P-free diet that was used to estimate the basal endogenous losses of P was also formulated. The ATTD of P in whey powder and in whey permeate was greater (P < 0.001) than in low-ash whey permeate (84.3 and 86.1 vs. 55.9%), but the STTD values for P were not different among the 3 ingredients (91.2, 93.1, and 91.8% in whey powder, whey permeate, and low-ash whey permeate, respectively). In conclusion, whey permeate contains less GE, DE, and ME than whey powder and low-ash whey permeate, but all 3 ingredients have an excellent digestibility of P.     

Effect of protein and(or) carbohydrate fractions of dried whey on performance and nutrient digestibility of early weaned pigs

One hundred eighty 3-wk-old pigs (initial weight 4.8 kg) were utilized in a 35-d growth trial to determine the effects of the carbohydrate and(or) protein fraction of dried whey on pig performance. In addition, 30, 3-wk-old pigs (initial weight 4.9 kg) were used in two digestion trials to study the effects of the whey fraction on nutrient digestibility. Dietary treatments included a corn-soybean meal diet (control), control + 20% dried whey, control + 14.4% lactose, control + 2.1% lactalbumin, control + 14.4% lactose + 2.1% lactalbumin, and control + 8.4% whey protein concentrate. Pelleted diets containing equal lysine concentrations were fed. Lactose and lactalbumin were added at the same levels as provided by a 20% dried whey diet. Pigs fed diets containing milk products exhibited superior (P less than .05) ADG and efficiency of feed utilization and greater (P less than .05) apparent digestibilities for DM, energy and N compared with pigs fed the control diet. Including either lactose or lactalbumin in the diet for the early weaned pig resulted in similar gain, feed efficiency and nutrient digestibility. These results indicate that both the carbohydrate (lactose) and protein (lactalbumin) fractions of dried whey are important in explaining the beneficial response to dried whey elicited in the weanling pig.     

Isoleucine requirement of growing (25 to 45 kg) pigs

Three pig bioassays and two digestibility trials were conducted to determine the true digestible Ile requirement for maximal weight gain and minimal plasma urea nitrogen (PUN) of growing (25 to 45 kg) pigs. In Exp. 1, an Ile-deficient basal diet was developed and confirmed to be markedly deficient in Ile, yet fully efficacious when fortified with surfeit Ile. This diet contained corn, red blood cells, and soybean meal as Ile sources, and was analyzed to contain 15.5% crude protein, 0.34% Ile, and 0.95% lysine; metabolizable energy was calculated to be 3,430 kcal/kg. True digestibility of Ile in the basal diet was 89% based on digestibility trials in ileal-cannulated pigs and cecectomized roosters. The first growth trial (Exp. 2) involved six dose levels of true digestible Ile (0.38 to 0.58%), which resulted in a quadratic (P < 0.02) response in weight gain by growing pigs over a 21-d period. The weight-gain data were fitted to both a single-slope broken line and a quadratic fit, and when the quadratic response curve was superimposed on the broken line, the point at which the quadratic curve first intersected the plateau of the broken line occurred at 0.50% true digestible Ile. This (objective) requirement estimate was similar to that determined by taking 90% of the upper asymptote of the quadratic fitted line. In Exp. 3, a replicated 5 x 5 Latin square, five barrows (square 1) and five gilts (square 2) together with five 4-d feeding periods and five levels of true digestible Ile were utilized. A linear (P < 0.01) decrease in PUN occurred as Ile was incremented, with an apparent plateau occurring at 0.50% true digestible Ile. The results of these experiments suggest that the true digestible Ile requirement of grower (25 to 45 kg) pigs is 0.50% of the diet, or 1.46 g/Mcal of metabolizable energy, somewhat higher than the 1.38 g/Mcal metabolizable energy estimated by the 1998 National Research Council Subcommittee on Swine Nutrition.     

Effects of nitrogen and energy source on nutrient digestibility in the young pig

Dried whole whey, lard or dried skim milk was added to a corn-soybean meal basal diet to determine the effect on apparent nitrogen (ND), energy (ED) and dry matter digestibility (DMD) in pigs weaned at 28 d. Four groups of four littermate barrows were allotted to the experimental diets and placed in individual metabolism pens for 12 d (3 d adjustment and three collection periods of 3 d each) after weaning. The study was a 4 X 3 factorial with diet and period as main effects. Addition of dried skim milk or dried whey to the diet resulted in higher values (P less than .05) for DMD and ED as compared with the basal or corn-soy and lard diet. Pigs fed added dried skim milk had improved (P less than .05) ND over pigs on other dietary treatments. All nutrient digestibility coefficients increased (P less than .05) from period 1 to period 2, and ND increased (P less than .05) from period 2 to 3. It was concluded that the young pig requires at least 6 to 9 d after weaning at 28 d to adjust to typical corn-soybean meal starter diets.     

Nutritional value of a new source of fermented soybean meal fed to growing pigs

Three experiments were conducted to test the hypothesis that the standardized ileal digestibility (SID) of amino acids (AA), concentrations of digestible energy (DE) and metabolizable energy (ME), and the standardized total tract digestibility (STTD) of P in a new source of fermented soybean meal (Fermex 200) are greater than in conventional soybean meal (SBM-CV). In experiment 1, 9 barrows (initial body weight: 9.17 ± 1.03 kg) were surgically fitted with a T-cannula in the distal ileum and allotted to a triplicated 3 × 3 Latin square design. A nitrogen-free diet and 2 diets that contained cornstarch and SBM-CV or Fermex 200 as the sole source of crude protein (CP), and AA were formulated. Results indicated that there were no difference between SBM-CV and Fermex 200 for SID of CP and AA. In experiment 2, 24 growing pigs (initial body weight: 14.19 ± 1.18 kg) were housed individually in metabolism crates. Pigs were allotted to a corn-based diet or 2 diets that contained corn and SBM-CV or corn and Fermex 200. Feces and urine samples were collected using the marker-to-marker approach with 5-d adaptation and 4-d collection periods. Results indicated that the concentration of DE and ME in Fermex 200 were not different from DE and ME in SBM-CV. In experiment 3, 40 barrows (initial body weight: 11.01 ± 1.38 kg) were allotted to 1 of 4 diets with 10 replicate pigs per diet. Four diets were formulated to contain Fermex 200 or SBM-CV and either 0 or 1,000 units/kg of microbial phytase. Pigs were housed individually in metabolism crates. Fecal samples were collected as explained for experiment 2. Results indicated that the STTD of P in Fermex 200 was greater (P < 0.01) than in SBM-CV, but the addition of microbial phytase to the diets increased the ATTD and STTD of P in SBM-CV, but not in Fermex 200 (interaction; P < 0.01). In conclusion, the SID of AA and concentrations of DE and ME in Fermex 200 were not different from values determined for SBM-CV, but the STTD of P was greater in Fermex 200 than in SBM-CV if microbial phytase was not added to the diet.     

Apparent ileal digestibility of amino acids and the digestible and metabolizable energy content of dry extruded-expelled soybean meal and its effects on growth performance of pigs

We conducted three experiments to determine the apparent ileal digestibility of amino acids (Exp. 1), metabolizable and digestible energy (Exp. 2), and feeding value (Exp. 3) of dry extruded-expelled soybean meal with (DEH) or without (DENH) hulls compared with solvent-extracted soybean meal with hulls removed (SBMNH). Soybeans used to produce DEH were unadulterated prior to extrusion, but those used for DENH were dehulled prior to extrusion. In Exp. 1, six nonlittermate barrows (initially 39 kg) were fitted with ileal T-cannulas and used in a replicated 3 x 3 Latin square design digestion trial. Experimental diets (0.80% total lysine) were cornstarch-based and contained soybean meal from one of the three different sources as the sole source of lysine. Apparent ileal digestibilies of nutrients were similar (P > 0.10) for DEH and DENH. Apparent ileal digestibilies of CP, Lys, Ile, Leu, Arg, Phe, and Val were greater (P < 0.05) for DEH and DENH than for SBMNH. In Exp. 2, six barrows (initially 41 kg) were fed three corn-based diets containing 25% of one of the three soybean meal sources. A fourth diet was fed at the end of the trial containing all ingredients except soybean meal, so that energy values of the soybean meal could be determined by difference. Digestible energy and ME contents were similar (P > 0.10) for DEH and DENH and both had greater (P < 0.05) DE and ME contents than SBMNH. In Exp. 3, pigs (n = 216, initially 10.6 +/- 1.3 kg and 35 +/- 3 d of age) were blocked by weight and allotted to six dietary treatments. Corn-soybean meal-based diets (0.95% digestible lysine and 3.44 kcal/g ME) containing DEH or DENH were compared with similar diets containing SBMNH or solvent-extracted soybean meal with hulls (SBMH). In addition, a diet containing a second expelled soybean meal with hulls (ESBM) was compared with a diet containing SBMH and soy oil. Growth performance of pigs fed diets containing DEH or DENH was not different (P > 0.10) than that of pigs fed corresponding diets containing SMBH or SBMNH. Pigs fed ESBM had lower (P < 0.05) ADG and G/F compared with its corresponding SBMH and soy oil diet. In conclusion, DEH and DENH are more digestible than conventional soybean meal and can be successfully used in swine diets.     

Digestion of soybean meal proteinin the equine small and large intestine at various levels of intake

Four mature pony geldings weighing an average of 134 kg and fitted with ileal cannulas were used in a 4×4 Latin square experiment to determine the digestibility of soybean meal (SBM) protein in different segments of the equine digestive tract at various levels of protein intake. A complete basal corn-based diet was supplemented with SBM to formulate four diets with increasing crude protein. The diets, labeled A (basal), B, C and D, contained 4.9%, 9.5%, 14% and 16.5% crude protein (as fed), and provided nitrogen, per feeding, at approximately 44.8, 84.3, 123.9 and 146.3 mg/kg of body weight, respectively. Chromic oxide was fed to measure ileal flow and fecal excretion. Digestion and absorption of nitrogen was determined from changes in nitrogen: chromium ratios, and true digestion of nitrogen was computed by regression analysis. True total tract digestion of nitrogen was 95.7%. True digestibility of nitrogen in the small intestine over the range of linearity was 72.2%, while true digestibility of nitrogen reaching the large intestine was 89.8%. These data indicate that the protein in SBM was almost completely digested in the equine digestive tract. Furthermore, approximately 75% of the digestible protein was digested prececally when nitrogen intake was less than approximately 125 mg/kg of body weight per feeding.     

Histidine requirement of the young pig

A histidine (HIS)-deficient, feather meal-corn-dried whey basal diet (19% protein and 3,200 Kcal ME/kg), supplemented with lysine, methionine and tryptophan, was employed to determine the HIS requirement of the growing pig between 10 and 20 kg live weight. Using a chick bioavailability growth assay, the HIS-deficient basal diet was found to contain .19% bioavailable HIS. A preliminary pig study established that the HIS-deficient basal diet was capable of supporting good growth of pigs when supplemented with sufficient L-HIS.HCl.H2O. In the second pig experiment, crossbred pigs with an average initial weight of 10 kg were kept in individual metabolism crates and were fed to appetite in two feedings the HIS-deficient basal diet supplemented with 0, .06, .12 or .18% L-HIS. Rate and efficiency of weight gain increased linearly between 0 and .12% supplemental HIS, but the highest supplemental level of HIS did not improve performance further. Plasma HIS increased, whereas plasma urea-N remained unchanged, as the level of dietary HIS increased. The third pig experiment employed narrower increments of .06, .09 or .12% supplemental HIS, and a linear response in both gain and feed efficiency occurred. Viewing all experiments together, the bioavailable HIS requirement of the 10- to 20-kg pig was .31% of the diet. Assuming an 85% bioavailability of HIS in commercial diets based on corn and soybean meal, the total HIS level needed in practice would be .36%.     

Apparent ileal digestibility of nutrients and amino acids in soybean meal,fish meal,spray‐dried plasma protein and fermented soybean meal to weaned pigs

This study sought to determine whether fermentation could increase apparent ileal digestibility (AID) of dry matter (DM), nitrogen (N), energy (E) and amino acids (AA) in fermented soybean meal (FSBM) greater than that of soybean meal (SBM) in weaned pigs. Four weaned pigs (10.00 ± 0.30 kg) were surgically equipped with T‐cannulas and randomly followed a 4 × 4 Latin square design of treatments (SBM, FSBM, fish meal and spray‐dried plasma protein). Overall, the fermentation process was able to reduce the amount of anti‐nutritional factors (ANF), including trypsin inhibitors, raffinose and stachyose, in the FSBM diet, which were significantly reduced by 39.4, 92.2, and 92.9%, respectively, as compared to the SBM diet. As a consequence of ANF reduction in FSBM, the AID of DM, N and E as well as AA was significantly greater with FSBM than SBM. Taken all together, the fermentation process improved the nutritional quality of SBM, due to ANF reduction, leading to improvement of digestibility of AA. As such, FSBM can be potentially used as a specialized feed ingredient, especially for young animal diets in an attempt to reduce diet costs.     

鳙鱼对10种蛋白质饲料原料中营养物质的表观消化率

本试验旨在研究鳙鱼(Aristichthys nobilis)对鱼粉(国产)、干酒糟及其可溶物(DDGS)、菜籽粕、米糠、豆粕、酶解羽毛粉、棉籽粕、小麦麸、玉米蛋白粉和花生粕中干物质、粗蛋白质、粗脂肪、总能以及氨基酸的表观消化率。试验饲料按照基础饲料和待测饲料原料7∶3的比例构成,并添加0.5%的三氧化二钇(Y2O3)作为外源指示剂。挑选初体重为(290.02±2.82)g的鳙鱼,随机分成11组,每组3个重复,每个重复10尾鱼。随机选取1组作为对照组投喂基础饲料,剩余10组为试验组分别投喂试验饲料。投喂1周后通过虹吸法收集粪便。结果表明:1)10种饲料原料中干物质、粗蛋白质、粗脂肪和总能的表观消化率的范围分别为69.9%~85.7%、73.5%~88.3%、81.2%~91.1%和81.9%~86.3%。2)在10种饲料原料中,米糠总能的表观消化率最高,而鱼粉的干物质、粗蛋白质和粗脂肪的表观消化率最高;酶解羽毛粉的干物质、粗脂肪和总能的表观消化率最低,玉米蛋白粉的粗蛋白质的表观消化率最低。3)各饲料原料氨基酸的表观消化率基本维持在65.59%~99.17%,且都以小麦麸较低。由此可见,鳙鱼对鱼粉具有很好的利用效果,其次是豆粕和花生粕,而酶解羽毛粉中粗蛋白质的表观消化率最低,小麦麸各氨基酸的表观消化率均比较低。     

Digestible tryptophan requirements of starting, growing, and finishing pigs.

Seven hundred eight crossbred pigs were used in growth and digestion trials to determine the digestible tryptophan (Trp) requirement of starting (6 to 16 kg), growing (22 to 50 kg), and finishing (55 to 97 kg) pigs. Each growth trial evaluated a corn-fish meal-corn gluten meal basal diet, the basal diet with five incremental additions of L-Trp, and a control corn-soybean meal diet. The tryptophan content of the six incremental diets ranged from .13 to .255% for starting pigs, .08 to .18% for growing pigs, and .063 to .163% for finishing pigs. Lysine contents of basal diets were 1.38, .90, and .72% for starting, growing, and finishing diets, respectively. In all trials, ADG, ADFI, and gain/feed increased (P less than .001) linearly and quadratically as dietary Trp increased. Broken-line regression analyses determined the total dietary Trp requirements needed to optimize performance to be .19, .13, and .09% (as-fed basis) for starting, growing, and finishing pigs, respectively. These concentrations equated to Trp intakes of .96, 2.18, and 2.88 g/d. A digestion trial using growing pigs (29 kg initially) determined the apparent ileal digestibility of Trp in the basal starting and growing diets to be 72 and 70%, respectively; a similar trial with finishing pigs (55 kg initially) found 59% Trp digestibility for the basal finishing diet. Mean digestibility of L-Trp was 97%. Based on these values and the total Trp requirements given above, the digestible Trp requirements are .15, .10, and .06% for starting, growing, and finishing pigs, respectively.     

Additivity of values for apparent and standardized ileal digestibility of amino acids in mixed diets fed to growing pigs

The objective of this experiment was to determine whether the digestibility of CP and AA in a mixed diet fed to growing pigs is better predicted when based on standardized ileal digestibility coefficients (SID) or apparent ileal digestibility coefficients (AID). Eight growing pigs (initial BW = 92.1 +/- 3.19 kg) were surgically equipped with a T-cannula in the distal ileum and arranged in an 8 x 8 Latin square design with eight diets and eight periods. Three of the diets contained corn, soybean meal (SBM), or canola meal (CM) as the sole source of CP and AA. Four mixed diets also were formulated using corn and soybean meal (CS); corn and canola meal (CCM); soybean meal and canola meal (SCM); or corn, soybean meal, and canola meal (CSCM). A N-free diet was used to measure the basal ileal endogenous losses (IAAend) of CP and AA. Pigs were fed each of the eight diets during one 7-d period, and ileal digesta were collected during two 10-h periods on d 6 and 7. The AID values were calculated for CP and AA in all diets, except the N-free diet. By correcting the AID for IAAend, the SID for CP and AA in each of the seven protein-containing diets were calculated. As expected, the AID for CP and the majority of AA were greater in SBM than in corn and CM (P < 0.05); however, the SID for CP and most AA did not differ between corn and SBM. For the majority of the AA, SID were less (P < 0.05) in CM than in the other two ingredients. Using the AID and the SID that were measured for CP and AA in corn, SBM, and CM, the AID and the SID in the four mixed diets were predicted and compared with the measured values for these diets. For the three mixed diets containing corn, the measured AID for CP and most AA were greater (P < 0.05) than the predicted AID, but with a few exceptions, no differences between predicted and measured values for SID were observed. For the diet based on SCM, there were no differences between predicted and measured values regardless of the procedure used, except for the AID of Ser. The results of this experiment demonstrate that the digestibility coefficients for a mixed diet containing low-protein feed ingredients, such as corn, are more accurately predicted using SID than AID.