Low-phytic acid corn improves nutrient utilization for growing pigs.

Thirty-five crossbred barrows averaging 14.5 kg initial BW were used in a 5-wk experiment to compare the P availability and nutritional value of a low-phytate hybrid corn (LPC, 0.26% total P, 0.08% phytic acid P) homozygous for the lpa 1-1 allele with a nearly isogenic normal hybrid corn (NC, 0.25% total P, 0.20% phytic acid P). The pigs were fed individually twice daily in metabolism pens. Three semipurified diets were created in which corn was the only source of phytate. Diet 1 contained 72% NC, 0.15% estimated available P (aP) and 0.55% Ca. Diet 2 contained 72% LPC, 0.24% aP, and 0.55% Ca. The only differences between Diets 1 and 2 were the source of corn and the levels of aP. No inorganic P (iP) was added to these diets in order to measure the animal response to the different levels of aP in the corn hybrids. Diet 3 was NC Diet 1 supplemented with iP to equal the level of aP in LPC Diet 2. Diets 4 and 5 were practical corn-soybean meal diets formulated with each corn to meet all minimum nutrient requirements and contained 0.30% aP and 0.65% Ca. For the semipurified diets, pigs fed LPC Diet 2 had higher (P < 0.01) growth performance, bone breaking strength, P absorption and retention, Ca absorption and retention, and N retention than pigs fed NC Diet 1. However, when the NC diet was supplemented with iP to equal the aP in the LPC diet, most criteria were similar (P > or = 0.2), indicating an equal nutritional value for both corn hybrids after adjusting for phytate level. The only treatment difference, other than P excretion, between the practical corn diets supplemented with soybean meal was a higher (P < 0.05) bone breaking strength for pigs fed LPC Diet 5 compared with NC Diet 4. The use of LPC in pig diets reduced P excretion in swine waste by 50 and 18.4% in the semipurified and practical diets, respectively, compared with NC. Using our in vitro procedure designed to simulate the digestive system of the pig, the availability of P for pigs was estimated at 56% for LPC and 11% for NC.     

Energy utilization of low-protein diets in growing pigs

Three trials were conducted to measure the effects of reducing the dietary CP content on digestive and metabolic utilization of N and energy in growing pigs. Sixty barrows weighing about 65 kg were used. In Trial 1, four semisynthetic diets with CP content decreasing from 18.9 to 12.3% were formulated. In Trials 2 and 3, two diets with 17.4 and 13.9% CP were formulated using conventional ingredients. In the three trials, diets were supplemented with variable amounts of industrial AA in order to maintain a constant standardized digestible lysine/NE ratio (0.76 g/MJ) and ratios between essential AA relative to lysine of at least 60, 65, 20, 60, and 70% for methionine + cystine, threonine, tryptophan, isoleucine, and valine, respectively. In Trials 1 and 2, feed was given in four meals per day, whereas, in Trial 3, two feeding frequencies (two and seven meals per day) were compared. Five or six N and energy balance (indirect calorimetry) measurements were conducted for each treatment, and components of heat production were estimated. Results of Trial 3 showed no effect of meal frequency on either N or energy utilization. Reduction of dietary CP content had no effect on N retention or animal performance but markedly decreased N excretion (-40% in Trials 2 and 3, and -58% in Trial 1). In the three trials, the lower N excretion with low-CP diets was accompanied by a reduction in urinary energy loss equivalent to 3.5 kJ/g of decrease in protein intake. Data of the three trials indicated that heat production was lower when CP was reduced (-7 kJ/g decrease in protein intake). This lower heat production was attributed to a reduction of the thermic effect of feed, whereas heat production associated with physical activity and maintenance were not affected. Reduction of dietary CP was associated with higher energy gain, mainly as fat. But, this effect was no longer significant when data were adjusted for similar NE intakes. These results confirm the possibility of limiting N excretion, while maintaining a high level of performance, by reducing CP level in the feed with adequate AA supplementation. This study also confirms the superiority of the NE system (in comparison with DE or ME systems) for predicting performance and energy gain of pigs and controlling carcass adiposity, especially in situations of feeds with variable CP contents.     

Protein metabolism in growing pigs fed corn or cassava peel based diets containing graded protein levels

Sixty-four Large White cross Landrace weanling pigs were randomly allotted to eight treatments in a two by four factorial arrangement. The two dietary variables were cassava peel (0 and 40 per cent) and crude protein (20, 15, 10 and 5 per cent). Total serum protein concentration was significantly (P less than 0.01) reduced by protein deficiency and by its interaction with cassava peel. The multiple coefficient of determination (R2) showed that protein intake was the primary factor determining changes in serum protein. R2 values for cyanide intake (independent variable) on serum protein (dependent variable) increased from day 30 to 90 of the trial. Serum urea was increased on the 5 per cent protein diets on days 60 and 90 of the trial. The R2 values for cyanide and protein intake on serum urea concentration increased from day 30 to day 90 of the trial. Serum creatinine increased (P less than 0.05) on the 5 per cent protein diet on day 90 of the trial. The R2 value for the effects of protein intake on serum creatinine was higher than for cyanide intake on days 30 and 90. The results confirm the progressive and pronounced effects of long term cyanide intake on serum nitrogenous metabolites in pigs consuming between 110 and 120 ppm hydrocyanic acid, especially in diets containing 10 per cent or less protein.     

家禽烟酸缺乏症

烟酸又名尼克酸,包括烟酸(吡啶-3-羧酸)和烟酰胺(动物体内烟酸的主要存在形式)两种物质,均具有烟酸活性。烟酸易变成烟酸酰胺(小肠粘膜上),在组织中与蛋白质结合,变成辅酶NAD (烟酰胺腺嘌呤二核苷酸)和NADP (烟酰胺腺嘌呤二核苷酸磷酸),是氧化还原反应中的氧化态辅酶。烟酸     

低蛋白日粮对生长猪及育肥猪的影响

选取初始体重为25kg的杜×大×长三元健康生长猪176头及初始体重为50kg的杜×大×长三元健康育肥猪144头。采用单因子设计,分为对照组和试验组;对照组中日粮按照NRC（1998）营养需要量推荐配制,试验组在NRC推荐的日粮粗蛋白质水平上降低4个百分点探讨低蛋白质日粮对生长猪和育肥猪生长性能的影响。结果表明：生长猪试验组日增重比对照组增加了46g,提高幅度为6．82％：料肉比比对照组低10．96％：增重成本节约0．89元／kg体重。育肥猪试验1组日增重较高．比对照组增加23g．提高幅度为3．09％。试验2组与对照组日增重相当;试验1组、试验2组料肉比分别比对照组降低1．15％和3．2％;试验1组、试验2组增重成本分别比对照组节约0．44元／kg体重和0．49元／kg体重;试验组瘦肉率与对照组相比没有显著差异。从各指标的趋势上看．试验组的生长表现和经济效益均优于对照组．     

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.     

Self-selection by growing pigs of diets differing in lysine content

Two 42-d experiments were conducted with 60 and 100 Large White growing pigs, initially weighing 17.7 and 18.3 kg, respectively, to determine their ability to select between diets varying in lysine content. Dietary lysine levels ranged from .60 to 1.40%. A common basal diet (17% crude protein, 3.3 Mcal digestible energy/kg) based on corn, soybean meal and peanut meal was used in both experiments. When offered a choice between deficient (.60% lysine) and balanced (.85% lysine) diets, the pigs consumed a higher proportion of the balanced diet. However, they did not discriminate between diets deficient in lysine (.60%) or containing excess lysine (1.16 or 1.40%). There were differences in diet preference over time. Pigs offered the deficient diet (.60%) and balanced diet (.85% lysine) progressively chose a higher proportion of the balanced diet as the trial progressed, but pigs offered a marginally deficient diet (.72% lysine) and a diet with excess lysine (1.21%) consumed a higher proportion of the high lysine diet during the first 3 wk of the experiment, but not during the last 2 wk of the experiment. These differences could be explained by the fact that the preference for a higher lysine diet at a given age depends on its proximity to the optimal level for growth, but also on the range between self-selected lysine concentrations.(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.     

The digestive fate of Escherichia coli glutamate dehydrogenase deoxyribonucleic acid from transgenic corn in diets fed to weanling pigs

Corn containing genetically engineered plasmid DNA encoding an Escherichia coli glutamate dehydrogenase (gdhA) was fed to 19-d-old weanling swine to trace the digestive fate of the transgenic DNA. Eight pens of 8 pigs were fed a commercial (nongdhA) starter for 2 wk. One pig was randomly selected from each pen for 0-h control samples. The remaining 56 pigs were transitioned onto a corn-soybean meal diet and fed a diet containing 58% gdhA corn for approximately 1 wk; immediately thereafter, liver, 10th rib muscle, white blood cells, and plasma from the hepatic portal vein and ingesta from the stomach, distal ileum, and large intestine were collected. The DNA was extracted and the concentration determined via spectrophotometry. Polymerase chain reaction and gel electrophoresis were performed with primers designed to amplify 490 bp that included the plasmid's ligation site between the maize ubiquitin and the gdhA genes. The gdhA corn-derived DNA and diet served as positive assay controls, and conventional corn DNA and distilled water acted as negative assay controls. Detection limits were 0.99 fg of target DNA confounded with 500 ng of conventional corn DNA per each 20 &L reaction. Transgenic DNA was detected in 71.43% of the stomach and 1.79% of the ileal ingesta samples from treatment animals but was not detected in the large intestine, white blood cells, plasma, liver, or muscle samples. Transgenic DNA was not detected in any sample from 0-h control animals. Stomach and ileal ingesta samples were further analyzed using real-time PCR. With an estimated limit of detection of 1.049 ag/microL, 89.29% of the stomach ingesta samples were positive (average 1.56 fg target DNA). The proportion of transgenic DNA to total DNA differed between diet and stomach ingesta samples (P < 0.001). Despite the greater sensitivity of real-time PCR, target DNA was detected in only 1.79% of ileal ingesta. These data suggest that the gdhA transgene began degradation in the stomach and was nondetectable in the large intestine.     

Evaluation of diets contaminated with aflatoxin and ochratoxin fed to growing pigs

The effects of dietary aflatoxin and ochratoxin, fed singly and in combination, were evaluated in growing crossbred pigs. Five barrows (7 weeks old at beginning of study) per group were fed either control feed, 2.0 mg of aflatoxin (AF)/kg of feed, 2.0 mg of ochratoxin (OA/kg of feed, or 2.0 mg of AF and 2.0 mg of OA/kg of feed for 28 days. Production performance, serum biochemical, hematologic, and pathologic evaluations were made. Body weights were reduced by the combination treatment, whereas body weight gain was decreased by all toxin treatments. The effect of AF and OA in combination on body weight gain was additive. Liver weights were increased by the combination treatment, whereas kidney weights were increased only in the OA group. Aflatoxin caused decreases in serum calcium, sodium, phosphorus, urea nitrogen, cholesterol, and glucose concentrations, whereas OA alone caused decreases in serum phosphorus, cholesterol, and hematologic values. The AF-OA treatment induced decreases in mean corpuscular volume, packed cell volume, and in serum concentrations of phosphorus, cholesterol, and urea nitrogen. The AF-OA treatment increased serum alkaline phosphatase activities and triglycerides. It was concluded that AF and OA, singly or in combination, can affect clinical performance, serum biochemical and hematologic values, and organ weights of barrows. Although values of some measurements were affected more by the combination than by either toxin alone and suggested synergism or antagonism, the toxic interactions could best be described as additive.     

陈化玉米在生长猪上的营养价值评定

试验旨在评定饲粮中添加陈化玉米对生长猪的营养价值影响。选择平均体重为(33.00±0.95) kg的健康DLY三元杂交猪40头,按照体重相近的原则,随机分为对照组和陈化玉米组两个组,每组10个重复,每个重复2头猪。对照组饲喂含60%新玉米的饲粮,陈化玉米组用陈化玉米等量替代新玉米。试验分为30 d的生长试验和12 d的消化代谢试验,总计42 d。结果表明:①与对照组相比,陈化玉米组对生长猪的平均日采食量(ADFI)、平均日增重(ADG)和料重比(F/G)无显著影响(P>0.05);②与对照组相比,陈化玉米组对生长猪的粗蛋白质表观消化率极显著提高了10.10%(P<0.01),对灰分表观消化率极显著降低了36.63%(P<0.01);③与对照组相比,陈化玉米组对生长猪天门冬氨酸、苏氨酸、丝氨酸、甘氨酸、缬氨酸、赖氨酸、组氨酸和精氨酸的表观消化率分别极显著的提高了9.85%、10.09%、6.58%、16.17%、14.78%、12.00%、7.45%和5.56%(P<0.01),对谷氨酸、丙氨酸和胱氨酸的表观消化率显著提高了3.48%、4.11%和4.71%(P<0.05),对异亮氨酸的表观消化率有提高的趋势(P=0.071);④与对照组相比,陈化玉米组对生长猪的饲粮表观消化能和代谢能无显著影响(P>0.05)。结果提示,饲粮中使用60%的陈化玉米对生长猪的生长性能、干物质、粗脂肪、粗纤维、酸性洗涤纤维、中性洗涤纤维的表观消化率以及饲粮表观消化能和代谢能的影响不显著,但能极显著提高粗蛋白质和氨基酸的表观消化率。     

Nitrogen balance and ileal amino acid digestibility in growing pigs fed diets reduced in protein concentration

Two studies were conducted to assess the effect of dietary protein reduction on N utilization, N excretion, and AA digestibility in growing pigs. The objective was to determine whether pigs fed diets with a reduced CP concentration could maintain the same N retention as pigs fed an adequate diet. The second objective was to test whether reducing dietary CP concentration decreases AA digestibility. In each study, six barrows were allotted to one of six dietary treatments in a Latin square design. Treatments consisted of four corn-soybean meal-based diets containing 15, 12, 9, and 6% CP, a casein-based diet containing 15% CP, and a protein-free diet. Crystalline AA were included in the 12, 9, and 6% CP diets. The indispensable:dispensable AA ratio was maintained at 45:55 with the addition of L-glutamic acid to the 9 and 6% CP diets. The casein-based and protein-free diets were used to determine endogenous total tract N and ileal AA losses. In the first study, total N losses and N absorbed decreased linearly (P < 0.001) as dietary CP concentration decreased from 15 to 6%. Both a linear (P < 0.001) and a quadratic (P < 0.05) decrease in N retention were found with decreasing dietary CP concentration. Nitrogen retained as a percentage of intake and absorbed increased (P < 0.001) as dietary CP concentration was reduced from 15 to 6%. In the second study, six barrows were surgically fitted with a T-cannula at the terminal ileum to determine ileal AA digestibility. For all dispensable and most indispensable AA, apparent and standardized ileal digestibility increased linearly (P 0.01, and for arginine, P < 0.05) as dietary CP concentration decreased. These results indicate that dietary CP concentration can be decreased from 15 to 12% with crystalline AA supplementation to meet an ideal AA profile without adversely affecting N retention, and that decreasing dietary CP concentration from 15 to 6% increases both dispensable and indispensable AA ileal digestibility.     

Ileal amino acid digestibility and performance of growing pigs fed wheat-based diets supplemented with xylanase

Two experiments were conducted to determine the effect of supplementation of xylanase to a wheat-based diet on the apparent ileal digestibility (AID) of AA and the performance of growing pigs fed diets limiting in AA. In Exp. 1, eight pigs (average initial BW = 20.5+/-1.2 kg) fitted with a simple T-cannula at the distal ileum, were fed four diets according to a repeated 4 x 4 Latin square design. Diet 1 was a basal diet that contained 97.6% wheat. Diets 2, 3, and 4 were the basal diet supplemented with xylanase at rates of 5,500, 11,000, and 16,500 units of xylanase activity (XU), respectively (as-fed basis). There were linear and quadratic effects (0.062 < P < 0.001) of xylanase supplementation on the AID of CP and most of the AA. The largest increases in AID of CP and AA were obtained when xylanase was supplemented at a rate of 11,000 XU; no further increases were observed with xylanase supplementation at a rate of 16,500 XU. In Exp. 2, 30 pigs (average initial BW 21.4+/-1.8 kg) were randomly allotted to six dietary treatments. Diets 1 to 4 were similar to those used in Exp. 1. Diet 5 was the same as Diet 1, but supplemented with 0.53% lysine, 0.12% threonine, and 0.05% methionine. Diet 6 (positive control diet) was a wheat-soybean meal diet that contained 18.2% CP (as-fed basis). The total contents of lysine, threonine, and methionine were similar for Diets 5 and 6. There was a linear effect of xylanase supplementation on ADG (P = 0.093) and feed:gain ratio (P = 0.089), and a quadratic effect on ADG (P = 0.067) and feed:gain ratio (P = 0.074). But, the greatest response was obtained with the supplementation of 11,000 XU. The supplementation of lysine, threonine, and methionine to Diet 1 increased (P = 0.001) ADG and ADFI and improved (P = 0.01) feed:gain ratio. There was no difference (P = 0.508) in the performance of pigs fed the AA-supplemented or control diet. In conclusion, the supplementation of xylanase to a diet in which wheat provided the sole source of protein and energy improved the AID of AA, ADG, and feed:gain ratio; however, this improvement was very small compared with that obtained with the supplementation of synthetic amino acids.     

Relationship between dietary amino acid release kinetics and nitrogen deposition in growing pigs

Although the protein content of swine diets is formulated based on the ileal digestibility of protein and amino acids(AA) under current nutrition requirements, the nitrogen utilization efficiency of swine varies based on protein source, which may be related to AA release kinetics. In this experiment, a 2 × 2 factorial arrangement with casein(CAS)-enriched or corn gluten meal(CGM)-enriched protein sources at different digestible crude protein levels(normal [N], 13%; and low [L], 11%) were applied...     

不同能量饲粮添加植酸酶对杂交仔猪生长性能影响的研究

选用48头长白×荣昌杂交仔猪进行2个2×2因子的生长试验,试验期2周,每个试验均设2个有效磷水平(0.36%、0.26%)、2个植酸酶添加水平(0、750FTU/kg),共4个处理组,每个处理组设6个重复,每个重复1头仔猪。试验1为高能水平(DE:14.27MJ/kg),试验2为低能水平(DE:12.8MJ/kg)。结果表明:在试验1饲粮中添加植酸酶,仔猪平均日增重(ADG)、增重/代谢体重(GPW)、G/F分别提高8.1%、6.4%、3.6%;每千克增重的饲粮成本(CPG)降低3.1%;降低饲粮有效磷水平后,ADG、GPW、G/F分别降低1.5%、6.1%、3.5%;CPG增加0.4%(P>0.05)。在试验2饲粮中添加植酸酶,仔猪ADG、GPW、G/F、分别提高10.6%、7.2%、7.9%;每千克增重的饲粮成本(CPG)降低6.6%;降低饲粮有效磷水平后,ADG、GPW、G/F分别降低3.8%、3.3%、3.2%;CPG增加3.0%(P>0.05)。由此表明,在本试验条件下,饲粮中添加植酸酶能够提高仔猪的生长性能,降低仔猪生长的饲粮成本。     

Factors affecting the variability in ileal amino acid digestibility in corn distillers dried grains with solubles fed to growing pigs

Two experiments were conducted to compare the ileal digestibility of AA in distillers dried grains with solubles (DDGS) sourced from different regions (IL, MN, KY), to compare AA digestibility in DDGS and in distillers dried grains (DDG) and to compare AA digestibility in DDGS from ethanol production (DDGS(ethanol)) and DDGS from beverage production (DDGS(beverage)). In Exp. 1, five samples of DDGS(ethanol) were sourced from Minnesota (MN1, MN2), Illinois (IL1, IL2), and from Kentucky (KY). In Exp. 2, six samples of DDGS(ethanol), 1 sample of DDG, and 1 sample of DDGS(beverage) were used to compare values for apparent ileal digestibility and standardized ileal digestibility (SID) of AA between DDGS(ethanol) and DDGS(beverage) and between DDG and DDGS(ethanol). Results of Exp. 1 showed that the SID of Lys in DDGS from MN2 (72.8%) was greater (P < 0.01) than in DDGS from MN1 (66.8%), IL1 (66.8%), and KY (65.8%) but not different from IL2 (70.1%). Except for Leu and Glu, no differences in SID for any of the other AA were observed among the 5 sources of DDGS. In Exp. 2, the SID for Lys in DDGS(beverage) was greater (P < 0.01) than in DDGS(ethanol) (69.3 vs. 64.8%), but for CP and all other AA except His, no differences between the 2 types of DDGS were observed. The SID for most AA in DDG were greater (P < 0.05) than in DDGS(ethanol), which suggests that the AA in the solubles that are added to DDGS may be less digestible than the AA in DDG. In conclusion, results of these experiments confirm that the digestibility of Lys is more variable among sources of DDGS than the digestibility of other AA. However, the SID of AA among DDGS sources within a region can vary as much as among DDGS sources from different regions, and AA in DDGS(beverage) may be as digestible as AA in DDGS(ethanol). The digestibility of AA in DDG is greater than in DDGS, which indicates that AA in the solubles have a lower digestibility than AA in DDG.     

普通玉米、糯玉米和蒸汽压片玉米对生长猪能量和营养物质消化率的影响

研究的目的是通过饲喂生长猪普通玉米、糯玉米和蒸汽压片玉米来测定其消化能、代谢能和营养物质的表观消化率。     

Calcium, phosphorus, and amino acid digestibility in low-phytate corn, normal corn, and soybean meal by growing pigs

Nine growing barrows were equipped with a T-cannula in the distal ileum and used to determine apparent ileal (AID) and apparent total-tract digestibility (ATTD) coefficients of Ca and P in low-phytate corn, normal corn, soybean meal, and in diets where soybean meal was mixed with low-phytate corn or normal corn. The AID and the standardized ileal digestibility coefficients (SID) of CP and AA also were determined. The animals (initial BW = 29.3 +/- 1 kg) were allotted to a 9 x 9 Latin square with nine diets and nine periods. Three diets contained low-phytate corn, normal corn, and soybean meal as their sole source of CP, AA, Ca, and P, respectively. Three additional diets were identical to these diets except that limestone and monosodium phosphate were added. Two diets contained low-phytate corn or normal corn and soybean meal, limestone, and monosodium phosphate, and the final diet was a N-free diet. The AID and ATTD of Ca were higher (P < 0.05) for low-phytate corn than for normal corn (70.0 and 69.1% vs. 47.4 and 49.6%, respectively). The AID and ATTD for Ca in soybean meal (50.9 and 46.7%, respectively) did not differ from values for normal corn but were lower (P < 0.05) than for low-phytate corn. The AID and ATTD for P from low-phytate corn (56.5 and 54.5%, respectively) were greater (P < 0.05) than from normal corn (28.3 and 28.8%, respectively), whereas soybean meal had intermediate AID and ATTD for P (37.2 and 38.0%, respectively). The AID and ATTD of P increased (P < 0.05) when monosodium phosphate was added to normal corn (44.9 and 49.8%, respectively) and soybean meal (49.6 and 46.2%, respectively), but adding monosodium phosphate to low-phytate corn, did not alter either AID (49.7%) or ATTD (50.7%) of P. No differences between AID and ATTD for Ca or P within the same diet were observed. The AID of Arg, Asp, Gly, Ile, Lys, Phe, Thr, and Val were greater (P < 0.05) in low-phytate corn than in normal corn. The AID of all AA in soybean meal were greater (P < 0.05) than in both types of corn, with the exception of Ala, Cys, Leu, and Met. The SID of Lys, Phe, and Thr were higher (P < 0.05) in low-phytate corn than in normal corn. Because low-phytate corn has a higher digestibility of Ca and P, less inorganic Ca and P need to be supplemented to diets containing low-phytate corn than to those containing normal corn, and P excretion may be decreased when low-phytate corn is used in the diet.     

犬烟酸缺乏症的诊治及初步研究

烟酸(nicotinic acid or niacin)也称作维生素B5,或维生素pp,分子式C6H5NO2。它是动物体必需的13种维生素之一,是一种水溶性维生素,属于维生素B族。烟酸在动物体内转化成具有生