发酵豆粕对猪生长性能和营养物质消化率的影响

文章旨在研究在育肥猪日粮中添加发酵豆粕对其生长性能及营养物质消化率的影响,试验选取60头三元杂交育肥猪,按照公母相同原则随机分为4组,每组15个重复,对照组饲喂基础日粮（玉米-豆粕型）,3个试验组分别按照5%、10%、15%发酵豆粕等量替代基础日粮中的豆粕,本次试验周期为60 d,试验结果表明,3个试验组末重均显著高于对照组（P <0.05）;5%发酵豆粕组、15%发酵豆粕组日平均增重显著高于对照组（P <0.05）,10%发酵豆粕组极显著高于对照组（P <0.01）;3组粗蛋白质、粗脂肪、粗纤维消化率显著或极显著高于对照组（P <0.05或P <0.01）,从营养物质消化率看,10%发酵豆粕组表现最佳。综合来看,用10%发酵豆粕替代育肥猪日粮中普通豆粕可帮助育肥猪更好地消化、吸收营养物质,提高育肥猪生长性能具有明显帮助。     

猪品种和饲粮对营养物质消化率的影响

本试验用酸不溶灰分作为天然标示剂的方法测定了13头体重80—100千克、遗传基因不同的肥育猪(纯种东辽黑猪2头,长白×东辽黑7头,汉普夏×东辽黑4头)时4种不同类型饲粮的干物质、能量和粗蛋白质的消化率。并用最小二乘法分析了猪品种、饲粮以及二者互作时对饲粮养分消化率的影响。分析结果表明,猪种和饲粮因素不仅对所测养分的消化率具有各自的影响,而且两者对干物质和能量的消化率存在显著的互作效应。这在一定程度上,反映了不同猪种对饲粮要求的特殊性。     

用酶制剂对生长猪营养物质消化利用率的影响

选择８头体重１７ｋｇ,在回肠末端安装改进“Ｔ”型瘘管的断奶公仔猪,随机分为两组,分别饲喂添加复合酶和对照日粮,进行两次重复代谢试验和回肠末端食糜消化酶活性测定。试验结果表明,酶制剂可使饲料中主要营养物质、氨基酸的消化利用率和回肠末端食糜中蛋白酶类的活性略有提高,但与对照日粮无显著差异。试验组对饲料干物质、有机物、粗蛋白质、粗灰分的消化率和消化能的转化率平均分别为８４．１６％,８８．７７％,８４．９     

不同厚度蒸汽压片处理对玉米活体外瘤胃发酵的影响

试验以未处理的玉米及两种不同厚度蒸汽压片玉米(压片厚度为1.5mm,SFC 1.5;压片厚度为2.0mm,SFC 2.0)为材料,采用营养成分分析、活体外人工瘤胃产气量试验,研究不同厚度蒸汽压片处理对玉米营养成分、淀粉糊化度和活体外发酵特性的影响。结果表明,不同厚度蒸汽压片处理显著降低玉米粗蛋白质和粗脂肪含量(P0.05),显著提高了玉米的淀粉糊化度(P0.05);并且显著提高了玉米在瘤胃液内的淀粉降解率和体外产气速度(P0.05),显著降低了瘤胃液中氨态氮(NH3-N)浓度(P0.05);降低压片厚度(1.5和2.0mm),蒸汽压片玉米淀粉糊化度增加约17%(88.76%和71.60%),SFC 1.5的体外产气速度、4h干物质和淀粉产气率显著高于SFC 2.0(P0.05)。不同厚度蒸汽压片处理对玉米瘤胃48h产气量、12和24h瘤胃液pH、总挥发性脂肪酸产量及乙酸、丙酸、乙酸/丙酸、异丁酸、异戊酸、戊酸摩尔比影响均不显著(P0.05)。综上所述,不同厚度蒸汽压片处理可显著提高玉米在瘤胃内淀粉降解率和降解速度,降低瘤胃液中氨态氮浓度,而对48h产气量及其他发酵参数没有明显影响。     

L-精氨酸对肥育猪生长性能、营养物质消化率、气体排放和肉质的影响

本研究旨在探讨饲粮中添加不同水平的L-精氨酸对育肥猪生长性能、营养物质消化率、有害气体排放和肉品质的影响。本试验选择240头平均初始体重为(53.80±1.85)kg的三元杂交猪(杜长大),根据体重随机分为3组,每组8个重复,每个重复10头猪。试验有3种饲料,对照组饲喂玉米-小麦-豆粕型饲料(精氨酸水平为0.94%),另外两组饲料分别在基础日粮中添加0.05%和0.1%L-精氨酸。结果显示,L-精氨酸对育肥猪生长性能、养分消化率和有害气体排放均无显著影响(P> 0.05)。而随着饲粮中L-精氨酸添加量的增加,肌肉大理石纹评分呈显著线性增加(P <0.05),蒸煮损失和肌肉滴水损失呈显著线性下降(P <0.05)。总的来说,目前研究结果表明,日粮添加1.0 g/kg L-精氨酸有利于提高肥育猪的肉品质。     

淀粉对育肥猪生长性能和营养物质消化率的影响

淀粉是一种无色无味的葡萄糖高聚体,加热后呈现透明的液体状,完全水解后会产生葡萄糖。淀粉的种类是多样的。本文就不同来源淀粉对育肥猪的生长和营养消化问题进行了阐述。主要淀粉来源为玉米、糯米和土豆淀粉,利用相关试验的结果认证淀粉的影响力度。希望笔者的研究能为相关养殖场主或者饲养员提供理论借鉴。     

储存时间对玉米猪有效能值和营养物质消化率的影响

本试验旨在研究储存时间对玉米猪消化能、代谢能和营养物质消化率的影响。试验采集储存时间分别为1、2、3、4、5年的普通黄色马齿型玉米样品。试验一:选用30头初始体重为(35.3±3.3) kg的杜×长×大三元杂交去势公猪,采用直接法测定5个玉米样品的消化能、代谢能和营养物质的表观全肠道消化率。试验二:选用6头初始体重为(35.3±2.0) kg装有简单T型瘘管的杜×长×大三元杂交去势公猪,采用6×6拉丁方试验设计,采用直接法测定5个玉米样品中粗蛋白质和氨基酸的表观和标准回肠末端消化率。结果显示:随着储存时间的延长,玉米中干物质和淀粉含量线性降低(P0.05)。除了精氨酸,储存时间对玉米中粗蛋白质和各氨基酸含量均未产生显著影响(P0.05)。随着储存时间的延长,玉米的消化能和代谢能以及总能、淀粉、中性洗涤纤维和酸性洗涤纤维的表观全肠道消化率呈线性降低(P0.05)。另外,随着储存时间的延长,玉米的粗蛋白质以及各氨基酸的表观和标准回肠末端消化率均线性降低(P0.05)。总而言之,随着储存时间的延长,玉米的猪消化能和代谢能以及纤维物质和氨基酸的消化率均线性降低,从而导致其饲用价值逐渐降低。     

甘露聚糖酶和玉米干酒糟及可溶物对生长育肥猪生长性能、营养物质消化率和肌肉特性的影响

设计了4个试验研究玉米干酒糟及可溶物（DDGS）配合甘露聚糖酶对生长育肥猪生产性能,能量和营养物质全消化道表观消化率（ATTD）,血液代谢指标和肌肉特性的影响。     

蒸汽压片玉米调控瘤胃发酵与营养物质消化的研究进展

玉米作为反刍动物重要能量饲料,在饲养实践中通常需要进行一定加工处理之后进行饲喂,以提高其养分利用率.蒸汽压片技术是目前一种重要的玉米加工方式,可以显著提高玉米淀粉全消化道消化率,并在维持瘤胃微生物正常发酵方面具有重要作用.本文综述了蒸汽压片玉米调控瘤胃中营养物质消化和微生物发酵的作用功效与机理,以期为蒸汽压片玉米的进一...     

Energy and nutrient digestibility in NutriDense corn and other cereal grains fed to growing pigs

Two experiments were conducted to measure the energy and nutrient digestibilities in NutriDense corn and other cereal grains. An additional objective was to evaluate the effect of balancing diets with AA on the values measured for DE and ME of corn varieties. In Exp. 1, 6 growing pigs were fitted with a T-cannula in the distal ileum and allotted to a 6 x 6 Latin square design to measure apparent ileal digestibility (AID) and standardized ileal digestibility (SID) values for CP and AA in NutriDense corn, yellow dent corn, barley, wheat, and sorghum. Diets based on each of the 5 cereal grains were formulated, along with a N-free diet. Results of this experiment showed that the AID for most indispensable AA were greater (P < 0.05) in NutriDense corn and wheat than in the other cereal grains. The SID for Lys in NutriDense corn (77.6%) was greater (P < 0.05) than in yellow dent corn (68.5%), and sorghum (56.9%), but not different from wheat (75.1%) and barley (71.7%). The SID for Arg and Met in NutriDense corn also were greater (P < 0.05) than in yellow dent corn (88.1 and 87.2% vs. 84.5 and 82.8%, respectively). For the remaining indispensable AA, no differences in SID between NutriDense corn and yellow dent corn were observed. For all AA, the lowest values (P < 0.05) for AID and SID were obtained for sorghum. If calculated as grams of standardized ileal digestible AA per kilogram of DM, concentrations of all indispensable AA in NutriDense corn were greater (P < 0.05) than in yellow dent corn, but barley and wheat had greater concentrations of most AA than yellow dent corn and NutriDense corn. In Exp. 2, 12 growing barrows were placed in metabolism cages, and the DE and ME of NutriDense corn and yellow dent corn were measured. Both grains were used in diets without or with crystalline AA supplementation. Each diet was fed to 6 pigs in a 2-period, changeover design. The DE and the ME in NutriDense corn (4,004 and 3,922 kcal/kg of DM, respectively) were greater (P < 0.01) than in yellow dent corn (3,878 and 3,799 kcal/kg of DM, respectively). Values for DE and ME were not affected by the addition of crystalline AA to the diets. It is concluded that NutriDense corn has a greater value than yellow dent corn in diet formulations due to increased concentrations of digestible, indispensable AA and energy. However, barley and wheat have greater concentrations, whereas sorghum has lower concentrations, of many digestible AA than NutriDense corn.     

Chemical composition,energy and amino acid digestibility in double-low rapeseed meal fed to growing pigs

Background:The nutritional value of rapeseed meal may be variable due to the variation of its chemical composition.And a precise understanding of the nutritional value of an ingredient is beneficial for the accurate diet formulation and reduction of feed costs.This study was conducted to determine the chemical composition,digestible energy(DE) and metabolizable energy(ME) content,and apparent ileal digestibility(AID) and standardized ileal digestibility(SID) of amino acids(AA) for growing pigs.Thirteen solvent-extracted double-low rapeseed meal(DLRSM) samples were obtained from the main double-low rapeseed producing areas in China.Methods:The DE and ME contents of the 13 DLRSM samples were measured in growing pigs(six pigs per DLRSM sample,average initial body weight(BW) = 48.3 kg).The AID and SID of AA of 10 DLRSM samples were determined in 12 crossbred barrows(average initial BW = 35.3 kg) by using two 6x6 Latin square designs.Each Latin square comprised one N-free diet and 5 DLRSM test diets.Results:The chemical composition of DLRSM varied among samples,and the coefficient of variation was greater than 10%for ether extract(EE),neutral detergent fiber(NDF),acid detergent fiber(ADF),calcium(Ca),and total glucosinolates.The AA content of DLRSM varied among samples especially for lysine(Lys) and methionine(Met).On a dry matter(DM) basis,the apparent total tract digestibility(ATTD) of gross energy(GE),the DE and ME and the ME:DE ratio of DLRSM averaged 62.39%,2862 kcal/kg and 2723 kcal/kg,and 94.95%,respectively.The mean value of SID of Lys was 70.52% which varied from 66.54-76.54%.The SID of crude protein(CP),Met,and threonine(Thr) averaged 72.81%,82.41%,and 69.76%,respectively.Conclusions:There was great variability in chemical composition especially in the concentration of EE,NDF and ADF,but no significant differences in energy content of the DLRSM samples were observed.In addition,the AID and SID of all AA were relatively similar among DLRSM samples except for that of Lys.     

Chemical composition,energy and amino acid digestibility in double-low rapeseed meal fed to growing pigs

Background

The nutritional value of rapeseed meal may be variable due to the variation of its chemical composition. And a precise understanding of the nutritional value of an ingredient is beneficial for the accurate diet formulation and reduction of feed costs. This study was conducted to determine the chemical composition, digestible energy (DE) and metabolizable energy (ME) content, and apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of amino acids (AA) for growing pigs. Thirteen solvent-extracted double-low rapeseed meal (DLRSM) samples were obtained from the main double-low rapeseed producing areas in China.

Methods

The DE and ME contents of the 13 DLRSM samples were measured in growing pigs (six pigs per DLRSM sample, average initial body weight (BW) = 48.3 kg). The AID and SID of AA of 10 DLRSM samples were determined in 12 crossbred barrows (average initial BW = 35.3 kg) by using two 6 × 6 Latin square designs. Each Latin square comprised one N-free diet and 5 DLRSM test diets.

Results

The chemical composition of DLRSM varied among samples, and the coefficient of variation was greater than 10 % for ether extract (EE), neutral detergent fiber (NDF), acid detergent fiber (ADF), calcium (Ca), and total glucosinolates. The AA content of DLRSM varied among samples especially for lysine (Lys) and methionine (Met). On a dry matter (DM) basis, the apparent total tract digestibility (ATTD) of gross energy (GE), the DE and ME and the ME:DE ratio of DLRSM averaged 62.39 %, 2862 kcal/kg and 2723 kcal/kg, and 94.95 %, respectively. The mean value of SID of Lys was 70.52 % which varied from 66.54–76.54 %. The SID of crude protein (CP), Met, and threonine (Thr) averaged 72.81 %, 82.41 %, and 69.76 %, respectively.

Conclusions

There was great variability in chemical composition especially in the concentration of EE, NDF and ADF, but no significant differences in energy content of the DLRSM samples were observed. In addition, the AID and SID of all AA were relatively similar among DLRSM samples except for that of Lys.     

Energy, phosphorus, and amino acid digestibility of high-protein distillers dried grains and corn germ fed to growing pigs

Three experiments were conducted to measure energy, P, and AA digestibility in 2 novel co-products from the ethanol industry [i.e., high-protein distillers dried grains (HP DDG) and corn germ]. These products are produced by dehulling and degerming corn before it enters the fermentation process. Experiment 1 was an energy balance experiment conducted to measure DE and ME in HP DDG, corn germ, and corn. Six growing pigs (initial BW, 48.9 +/- 1.99 kg) were placed in metabolism cages and fed diets based on corn, corn and HP DDG, or corn and corn germ. Pigs were allotted to a replicated, 3 x 3 Latin square design. The DE and ME in corn (4,056 and 3,972 kcal/kg of DM, respectively) did not differ from the DE and ME in corn germ (3,979 and 3,866 kcal/kg of DM, respectively). However, HP DDG contained more (P < 0.05) energy (4,763 kcal of DE/kg of DM and 4,476 kcal of ME/kg of DM) than corn or corn germ. Experiment 2 was conducted to measure apparent total tract digestibility (ATTD) and true total tract digestibility of P in HP DDG and corn germ. Thirty growing pigs (initial BW, 33.2 +/- 7.18 kg) were placed in metabolism cages and fed a diet based on HP DDG or corn germ. A P-free diet was used to measure endogenous P losses. Pigs were assigned to treatments in a randomized complete block design, with 10 replications per treatment. The ATTD and the retention of P were calculated for the diets containing HP DDG and corn germ, and the endogenous loss of P was estimated from pigs fed the P-free diet. The ATTD was lower (P < 0.05) in corn germ (28.6%) than in the HP DDG (59.6%). The retention of P was also lower (P < 0.05) in pigs fed corn germ (26.7%) than in pigs fed HP DDG (58.9%). The endogenous loss of P was estimated to be 211 +/- 39 mg per kg of DMI. The true total tract digestibility of P for HP DDG and corn germ was calculated to be 69.3 and 33.7%, respectively. In Exp. 3, apparent ileal digestibility and standardized ileal digestibility values of CP and AA in HP DDG and corn germ were measured using 6 growing pigs (initial BW, 78.2 +/- 11.4 kg) allotted to a replicated, 3 x 3 Latin square design. The apparent ileal digestibility for CP and all AA except Arg and Pro, and the standardized ileal digestibility for CP and all AA except Arg, Lys, Gly, and Pro were greater (P < 0.05) in HP DDG than in corn germ. It was concluded that HP DDG has a greater digestibility of energy, P, and most AA than corn germ.     

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.     

Amino acid digestibility in heated soybean meal fed to growing pigs

Heat treatment of soybean meal (SBM) is necessary to reduce the concentration of trypsin inhibitors, but excessive heat treatment may reduce AA concentration and digestibility because AA can be destroyed by the Maillard reaction. The objective of this experiment was to determine the effects of heat treatment of SBM on apparent ileal digestibility and standardized ileal digestibility (SID) of AA by growing pigs. A source of conventional dehulled SBM (48.5% CP) was divided into 4 batches. One batch was not additionally heated, 1 batch was autoclaved at 125°C for 15 min, 1 batch was autoclaved at 125°C for 30 min, and 1 batch was oven-dried at 125°C for 30 min. Four SBM-cornstarch diets were formulated, and each of the 4 batches of SBM was used as the sole source of dietary AA in 1 diet. A N-free diet was used to estimate basal endogenous losses of AA. Ten growing barrows with an initial BW of 25.3 ± 2.0 kg were individually fitted with a T-cannula in the distal ileum. Pigs were allotted to treatments in a replicated 5 × 5 balanced Latin square design with 5 diets and 5 periods. Each period lasted 7 d, and ileal digesta were collected on d 6 and 7 of each period. Results of the experiment indicated that the apparent ileal digestibility and SID of CP and all AA decreased linearly (P < 0.01) as the time of autoclaving increased from 0 to 30 min. The concentration of furosine and the color of samples of SBM indicated that autoclaving resulted in a Maillard reaction in the SBM. However, oven drying at 125°C for 30 min did not change (P > 0.10) the SID of CP and AA in the SBM or the furosine concentration, and the color in the oven-dried sample indicated that this sample was not heat damaged. In conclusion, the digestibility of all AA in autoclaved SBM is linearly reduced as the autoclaving time increases from 0 to 30 min. The reason for these changes is most likely that autoclaving at 125°C results in Maillard reactions in SBM.     

Determination of the energy value of corn distillers dried grains with solubles containing different oil levels when fed to growing pigs

This experiment used indirect calorimetry to determine the net energy (NE) content of five corn distillers dried grains with solubles (corn DDGS) containing different oil levels and to compare the NE obtained using indirect calorimetry with that calculated using previously published prediction equations. There were two samples of high‐oil DDGS, one sample of medium‐oil DDGS and two samples of low‐oil DDGS. Twelve barrows (initial BW of 32.8 ± 2.0 kg) were used in a repeated 3 × 6 Youden square design with three periods and six diets. The diets were comprised of a corn–soybean meal basal diet and five diets containing 29.25% of one of the corn DDGS added at the expense of corn and soybean meal. During each period, the pigs were individually housed in metabolism crates for 16 days which included 7 days for adaption to feed and environmental conditions. On day 8, the pigs were transferred to respiration chambers and fed one of the six diets at 2300 kJ ME/kg BW^0.6/day. Faeces and urine were collected from day 9 to 13 and heat production (HP) was also measured. From day 14 to 15, the pigs were fed 893 kJ ME/kg BW^0.6/day to allow them to adapt from the fed to the fasted state. On the last day of each period (day 16), the pigs were fasted and fasting HP was measured. The digestible energy value was 16.0, 17.1 and 15.3 MJ/kg DM, the metabolizable energy value was 14.6, 15.5 and 13.7 MJ/kg DM and the NE value was 10.7, 11.0 and 9.4 MJ/kg DM, for the high‐oil, medium‐oil and low‐oil corn DDGS, respectively. The NE obtained with indirect calorimetry in the present study did not differ from values calculated using previously published prediction equations.     

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.     

Determination and prediction of the apparent and standardized ileal amino acid digestibility in cottonseed meals fed to growing pigs

This experiment was conducted to evaluate the chemical composition and apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of amino acids (AA) in cottonseed meals (CSM) and to develop prediction equations for estimating AA digestibility for growing pigs based on the chemical composition and AA content of CSM. 10 CSM were collected from 10 provinces in China. 11 barrows (initial body weight: 34.4 ± 1.9 kg), fitted with an ileal T‐cannula, were allotted to 6 × 11 Youden square with 6 periods and 11 diets. The diets included one N‐free diet and 10 CSM test diets containing 40% CSM as the sole source of AA. The nitrogen‐free diet was used to measure the basal endogenous losses of CP and AA. The AID and SID for crude protein (CP), Lys, Met, Trp, and Thr among the 10 CSM differed (p < 0.05). With R² values exceeding 0.30, significant linear regression equations for CP, Lys, and Thr were obtained. The best fit equations for predicting the AID and SID of Lys were: AID of Lys = 82.94–0.65 neutral detergent fiber, with R² = 0.44, residual standard deviation (RSD) = 4.03 and p = 0.04; and SID of Lys = 135.34–1.01 neutral detergent fiber + 34.27 Thr – 58.06 Trp – 84.93 Met, with R² = 0.90, RSD = 1.42 and p = 0.01. In conclusion, the results of AID, SID and prediction equations could be used to evaluate the digestibility of CSM in growing pigs.     

Amino acid and energy digestibility in ten samples of distillers dried grain with solubles fed to growing pigs

The objective of this experiment was to measure the digestibilities of energy, CP, and AA in 10 samples of corn distillers dried grain with solubles (DDGS) and in corn fed to growing pigs. Twelve growing barrows (initial BW: 34.0 +/- 1.41 kg) were allotted to an 8 x 12 Youden square design with 8 periods and 12 animals. Ten of 12 diets were based on the 10 DDGS samples (66.7%), 1 diet was based on corn (97%), and the last diet was a N-free diet based on cornstarch and sucrose. Chromic oxide (0.3%) was included in all diets as an inert marker. Pigs were provided their respective diets at a level of 3 times their estimated energy requirement for maintenance. The apparent (AID) and standardized (SID) ileal digestibilities for CP and AA were measured in the 10 samples of DDGS and in corn using the direct procedure, but the apparent total tract digestibilities for DM and GE were estimated using the difference procedure. The concentration of DE in each sample of DDGS and in corn was also calculated. The results of the experiment indicated variation among the different sources of DDGS in AID and SID for Lys, which ranged from 35.0 to 55.9% and 43.9 to 63.0%, respectively. For Met, the SID varied between 73.9 and 84.7%. However, the variability among samples in the SID for CP, and for the indispensable AA other than Lys and Met, was relatively low and ranged between 6 and 8 percentage units (i.e., from 64.0 to 70.6%, 74.1 to 80.1%, and 67.4 to 75.3% for Thr, Trp, and Ile, respectively). The SID for Trp in corn (72.8%) was lower (P < 0.05) than in DDGS, but for the remaining indispensable AA, except Arg, the SID for corn were greater (P < 0.01) than for DDGS. The DE concentration in the 10 samples of DDGS varied (P < 0.001) from 3,382 to 3,811 kcal of DE per kg of DM. For corn, the DE was 3,845 kcal per kg of DM. It is concluded that the AID and SID for Lys vary among samples of DDGS, but for most other AA the AID and SID are relatively similar and vary only 6 to 8 percentage units among different samples. Future work should focus on identifying the reasons for the variation in the digestibility of Lys to avoid processing procedures that are detrimental to Lys digestibility.