固态发酵复合蛋白质对猪肠道消化生理及养分消化率的影响研究

本研究旨在比较饲喂固态发酵(SSF)复合蛋白质与未固态发酵(NSSF)复合蛋白质对生长猪肠道消化生理及养分表观消化率的影响.选择(27.7±3.3)kg的PIC生长阉公猪18头,随机分配到3个处理中,每个处理6个重复,每个重复1头猪,3个处理分别为基础饲粮组、NSSF组和SSF组.以玉米-豆粕型饲粮为基础饲粮,NSSF...     

不同梯度发酵豆粕对育肥猪生长性能、胴体性状及肉品质的影响

试验旨在研究不同梯度发酵豆粕等量替代普通豆粕对育肥猪生长性能、胴体性状及肉品质的影响.采用单因素完全随机试验设计,选择240头初始体重(61.25±2.31) kg的"杜×长×大"育肥猪,随机分为6组,每组8个重复,每个重复5头猪.对照组育肥猪饲喂玉米-豆粕型基础日粮,5个试验组依次采用5％、7％、9％、11％、13％...     

发酵玉米浆的营养价值评定及其对育肥猪生长性能和血清生化指标的影响

本试验旨在评定发酵玉米浆的营养价值并探究其对育肥猪生长性能和血清生化指标的影响。试验1采用全收粪法测定发酵玉米浆对猪的有效能值和营养物质表观消化率。选取12头初始体重为（27.60±2.50）kg的“杜×长×大”三元杂交去势公猪，随机分为2组，每组6个重复，每个重复1头猪。对照组饲喂玉米-豆粕型基础饲粮，试验组饲粮以发酵玉米浆替代基础饲粮中24.25%的供能组分。试验期12 d，包括7 d饲粮适应期和5 d粪尿收集期。试验2采用无氮饲粮和半纯合饲粮法测定发酵玉米浆氨基酸回肠末端消化率。选取6头初始体重为（37.17±1.17）kg装有简单T型瘘管的“杜×长×大”三元杂交去势公猪，随机分为2组，每组3头猪。采用2×2拉丁方设计，包括2个试验期和2个饲粮处理。每个试验期7 d，包括5 d饲粮适应期和2 d食糜收集期。试验饲粮包括1个以玉米淀粉-蔗糖为基础的无氮饲粮和1个含有40%发酵玉米浆的待测饲粮。试验3选取192头初始体重为（82.30±5.85）kg的“杜×长×大”三元杂交猪，随机分为4组，每组6个重复，每个重复8头猪（公母各占1/2）。对照组（CON组）饲喂玉米-豆粕-麦麸型基础饲...     

非淀粉多糖水解酶对肥育猪生长性能的影响

用256头健康的杜×长×大三元肥育阉割公猪(体重55千克左右)为试验对象研究肥育猪日粮中添加非淀粉多糖(NSP)水解酶对其生长性能的影响。试验分为玉米-豆粕型日粮组(A)、玉米-豆粕型日粮加酶组(B)、小麦-豆粕型日粮组(C)和小麦-豆粕型日粮加酶组(D)四个处理。每个处理四个重复,每个重复16头猪。四个处理的配方营养水平符合N R C的要求,且保持一致。结果表明:在玉米-豆粕型日粮中添加酶制剂与未添加组比较日增重增加了3.02%(P<0.05),而料肉比下降3.56%(P<0.05),采食量没有显著差异。小麦-豆粕型日粮中添加木聚糖酶组与未添加组比较采食量没有差异,日增重增加了6.70%(P<0.05),而料肉比下降了4.14%(P<0.05)。从本试验可以看出,无论是玉米-豆粕型日粮还是小麦-豆粕型日粮添加NSP复合水解酶都能不同程度地改善肥育猪生长性能,但在小麦-豆粕型日粮中添加NSP水解酶,肥育猪的生长性能改善更为明显。     

特种野母猪适宜日粮结构的研究

试验旨在研究不同能量来源对后备期特种野母猪生长性能和免疫指标的影响.试验采用2(日粮结构)×4(能量水平)因子设计,选用后备特种野母猪32头,随机分为8组,每组2个重复,每重复2头猪.“玉米-豆粕”型和“40％的稻谷-玉米-豆粕”型日粮各设4个能量水平.试验结果表明:1)生长性能,不同能量饲料组成的日粮对试验猪只的末质量、日增质量和料重比均未产生显著的影响.2)免疫指标,不同日粮结构对试验猪只血清免疫球蛋白M的影响显著,对其他各血清免疫指标的影响均不显著.说明“玉米-豆粕”型日粮在一定程度上可以提高猪只的生长速度.但“40％的稻谷-玉米-豆粕”型日粮可以显著降低特种野母猪的腹泻率,增强免疫力,提高猪的健康水平.     

豆粕和菜籽粕饲粮中添加新型蛋白酶对生长猪生长性能、养分消化率和血清生化指标的影响

本试验旨在探究豆粕和菜籽粕饲粮中添加新型蛋白酶对生长猪生长性能、养分消化率和血清生化指标的影响。采用2×2因子试验设计，试验因素分别为饲粮类型（玉米-豆粕型和玉米-豆粕-菜籽粕型）和蛋白酶水平（0和300 mg/kg）。选取初始体重为（21.40±1.59） kg的杜×长×大生长猪32头，随机分为4个组，每组8个重复，每个重复1头猪。各组分别饲喂玉米-豆粕型饲粮、玉米-豆粕型饲粮+300 mg/kg蛋白酶、玉米-豆粕-菜籽粕型饲粮以及玉米-豆粕-菜籽粕型饲粮+300 mg/kg蛋白酶。试验期21 d。结果表明：1）饲粮类型和蛋白酶水平对生长猪的生长性能无显著影响（P>0.05）。2）与玉米-豆粕型饲粮相比，玉米-豆粕-菜籽粕型饲粮显著降低了生长猪的有机物、粗纤维和粗蛋白质消化率（P<0.05）。3）饲粮中添加300 mg/kg蛋白酶显著提高了生长猪的有机物、粗脂肪、干物质、粗蛋白质、粗纤维以及总能消化率（P<0.05）。4）与玉米-豆粕型饲粮相比，玉米-豆粕-菜籽粕型饲粮显著降低了生长猪的血清尿素氮含量（P<0.05）。5）饲粮类型与蛋白酶水平对生长猪的生长性能...     

饲喂DDGS日粮对波尔山羊生长性能、瘤胃指标、胴体性状及经济效益的影响

本研究旨在评估波尔山羊不同阶段饲喂含有10％玉米DDGS的全混合日粮对其生长性能、瘤胃指标、胴体性状及饲养成本的影响.试验将初重一致的72头波尔山羊随机分为3组,每组3个重复,每个重复8头.3组山羊的饲喂时间均为20周,对照组在整个试验期饲喂玉米-豆粕型日粮,处理1组山羊在整个试验期饲喂玉米-DDGS型日粮,处理2组山...     

发酵豆粕对育肥猪生长性能的影响

本试验旨在评价饲粮中使用发酵豆粕对育肥猪生长性能的影响。采用单因子完全随机设计,挑选同一猪场健康猪216头,平均体重34kg,平均分为2个处理,每个处理6个重复,每个重复18头猪。基础饲粮为玉米-豆粕型饲粮,试验组在基础饲粮的基础上拿出9%豆粕+1%玉米粉用发酵豆粕替代。基础饲粮的各项营养指标满足育肥猪营养需要(NRC,2012)。试验期33天,前5天为预期,正式试验28天。结果表明:(1)与对照组相比,饲粮中使用发酵豆粕对育肥猪终末均重、平均日采食量(ADF)、耗料增重比差异不显著(P0.05),对平均日增重差异显著(P0.05);(2)与对照组相比,饲粮中使用发酵豆粕后育肥猪ADF增加77.35g·天~(-1)·头~(-1)(P0.05),平均日增重增加21.24g·天~(-1)·头~(-1)(P0.05),去除发酵豆粕水分后耗料增重比减少0.09(P0.05)。由此可见,在育肥猪日粮中使用发酵豆粕,可改善其生长性能,经济效益良好。     

棉籽粕替代日粮部分豆粕饲喂生长肥育猪的饲养试验

试验开展了棉籽粕部分替代豆粕饲喂生长肥育猪的饲养效果研究.选取54头体重约50 kg生长肥育猪随机分成对照组、试验Ⅰ和试验Ⅱ,每组设3个重复,每个重复6头.试验结果表明,在生长肥育猪日粮中添加4%、6%的棉籽粕代替等量豆粕,对生长肥育性能无明显影响,但降低了饲养成本,获得了较好的经济效益.     

日粮添加双低菜粕对生长猪生长性能的影响

本试验旨在研究不同添加量的双低菜粕等氮替代基础日粮中的豆粕作为主要蛋白质饲料日粮,调节日粮蛋白质、能量和氨基酸等常规营养指标水平一致后,对生长猪生长性能的影响.试验选择健康状况良好、胎次相近、平均体重为(42.06±1.28)kg的"杜×长×大"三元杂交生长猪132头,随机分为4组,每组3个重复,每个重复11头.对照组...     

Digestible and metabolizable energy of crude glycerol for growing pigs

The apparent DE and ME values of crude glycerol for growing pigs were determined in 5 experiments using crude glycerol (86.95% glycerol) from a biodiesel production facility, which used soybean oil as the initial feedstock. Dietary treatments were 0, 5, or 10% glycerol addition to basal diets in Exp. 1; 0, 5, 10, or 20% glycerol addition to basal diets in Exp. 2; and 0 and 10% crude glycerol addition to the basal diets in Exp. 3, 4, and 5. Each diet was fed twice daily to pigs in individual metabolism crates. After a 10-d adjustment period, a 5-d balance trial was conducted. During the collection period, feces and urine were collected separately after each meal and stored at 0 degrees C until analyses. The GE of each dietary treatment and samples of urine and feces from each pig were determined by isoperibol bomb calorimetry. Digestible energy of the diet was calculated by subtracting fecal energy from the GE in the feed, whereas ME was calculated by subtracting the urinary energy from DE. The DE and ME values of crude glycerol were estimated as the slope of the linear relationship between either DE or ME intake from the experimental diet and feed intake. Among all experiments, the crude glycerol (86.95% glycerol) examined in this study was shown to have a DE of 3,344 +/- 8 kcal/kg and an ME of 3,207 +/- 10 kcal/kg, thereby providing a highly available energy source for growing pigs.     

Digestibility of energy and phosphorus in ten samples of distillers dried grains with solubles fed to growing pigs

An experiment was conducted to measure DE and ME and the apparent total tract digestibility (ATTD) of energy, N, and P in distillers dried grains with solubles (DDGS) fed to growing pigs. Ten sources of DDGS were obtained from ethanol plants in South Dakota and Minnesota, and 11 diets were formulated. One diet was based on corn (96.8%), limestone, salt, vitamins, and microminerals. Ten additional diets were formulated by mixing the corn diet and each of the 10 sources of DDGS in a 1:1 ratio. Eleven growing pigs (initial BW of 29.3 +/- 0.42 kg) were allotted to an 11 x 11 Latin square design, with 11 periods and 11 pigs. Each of the 11 diets was fed to each pig during 1 period. Pigs were placed in metabolism cages that allowed for the total, but separate, collection of feces and urine. Samples were analyzed for GE, N, and P and energy and N balances, and the ATTD of GE, N, and P were calculated for each diet. By subtracting the contribution from the corn diet to the DDGS-containing diets, the energy and N balances and the ATTD for GE, N, and P for each source of DDGS were calculated. Results of the experiment showed that the DE and ME differed (P < 0.001) among the 10 sources of DDGS (3,947 to 4,593 kcal of DE/kg of DM and 3,674 to 4,336 kcal of ME/kg of DM). The average DE and ME in DDGS were 4,140 and 3,897 kcal/kg of DM, respectively. These values were not different from the DE and ME in corn (4,088 and 3,989 kcal/kg of DM, respectively). Based on the analyzed GE and nutrient composition of DDGS and the calculated values for DE and ME, prediction equations for DE and ME were developed. These equations showed that DE and ME in DDGS may be predicted from the concentration of ash, ether extract, ADF, and GE. The retention of N from DDGS was greater (P < 0.001) than from corn, but when calculated on a percentage basis, the N retention did not differ between DDGS and corn. The ATTD of P in DDGS was 59.1% on average for the 10 samples. This value was greater (P < 0.001) than the ATTD of P in corn (19.3%). It is concluded that the DE and ME in DDGS is not different from the DE and ME in corn. However, if DDGS is included in diets fed to growing swine, a greater portion of the organic P will be digested and absorbed, thus reducing the need for adding inorganic P to the diets.     

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.     

Net energy of oat bran,wheat bran,and palm kernel expellers fed to growing pigs using indirect calorimetry

The objectives of this experiment were to (a) determine the effects of fiber increase in diets on heat production (HP), (b) determine the net energy (NE) of oat bran (OB), wheat bran (WB), and palm kernel expellers (PKE) fed to growing pigs using indirect calorimetry (IC). Twenty‐four growing barrows (29.2 ± 2.6 kg) were randomly allotted to one of four diets with six replicate pigs per diet. Diets included a corn‐soybean meal basal diet and three test diets containing 30% OB, WB or PKE, respectively. During each period, pigs were individually housed in metabolism crates for 20 days, including 14 days to adapt to the diets. On day (d) 15, pigs were transferred to the open‐circuit respiration chambers for determination of daily total HP and were fed one of the four diets at 2.3MJ ME/kg body weight (BW)^0.6/day. Total feces and urine were collected for the determination of digestible energy (DE) and metabolizable energy (ME) and daily total HP was measured from d 15 to d 19 and fasted on day 20 for the measurement of fasting heat production (FHP). The apparent total tract digestibility (ATTD) of dry matter (DM), gross energy (GE), and organic matter (OM) were greater (p < 0.01) in pigs fed the basal diet compared with those fed the test diets. The ATTD of neutral detergent fiber (NDF) was lower (p < 0.01) in pigs fed the WB diet compared with those fed the basal, OB, or PKE diets. The ATTD of ether extract (EE) in pigs fed the PKE diet was greater (p < 0.01) compared with those fed the other diets. The average total HP and FHP in pigs fed the four diets were 1261 and 787 kJ/kg BW^0.6/d, respectively, and were not significantly affected by diet characteristics. The NE:ME ratio for diets ranged from 78.1 to 80.9%. The NE contents of OB, WB, and PKE were 10.93, 7.47, and 8.71 MJ/kg DM, respectively.     

Assessment of the feeding value of South Dakota-grown field peas (Pisum sativum l.) for growing pigs

Four experiments were conducted to investigate the feeding value of South Dakota-grown field peas (Pisum sativum L.) for growing pigs. In Exp. 1, 96 pigs (initial BW = 22 +/- 3.35 kg) were allotted to four treatment groups (four pigs per pen, six replicate pens per treatment) and fed growing (0.95% Lys) and finishing (0.68% Lys) diets containing 0, 12, 24, or 36% field peas (as-fed basis). There were no differences among the treatment groups in ADG, ADFI, or G:F. Likewise, there were no differences in backfat thickness or lean meat percent among treatment groups, but pigs fed diets containing 12, 24, or 36% field peas had greater (P < 0.05) loin depths than pigs fed the control diet. In Exp. 2, 120 pigs (initial BW = 7.8 +/- 1.04 kg) were allotted to four treatment groups 2 wk after weaning. Pigs were then fed diets containing 0, 6, 12, or 18% field peas (as-fed basis) during the following 4 wk. There were five pigs per pen and six replicate pens per treatment. Results of the experiment showed no differences in ADG, ADFI, or G:F among treatment groups. In Exp. 3, apparent (AID) and standardized (SID) ileal digestibility coefficients of CP and AA in field peas and soybean meal were measured using six individually penned growing pigs (initial BW = 36.5 +/- 2.1 kg) arranged in a repeated 3 x 3 Latin square design. The AID for Met, Trp, Cys, and Ser, and the SID for Met, Trp, and Cys were lower (P < 0.05) in field peas than in soybean meal; but for CP and all other AA, no differences in AID or SID were observed between the two feed ingredients. Experiment 4 was an energy balance experiment conducted to measure the DE and ME concentrations in field peas and corn. Six growing pigs (initial BW = 85.5 +/- 6.5 kg) were placed in metabolism cages and fed diets based on field peas or corn and arranged in a two-period switch-back design. The DE values for field peas and corn (3,864 and 3,879 kcal/kg DM, respectively) were similar, but the ME of corn was higher (P < 0.05) than the ME of field peas (3,825 vs. 3,741 kcal ME/kg DM). The results from the current experiments demonstrate that the nutrients in South Dakota-grown field peas are highly digestible by growing pigs. Therefore, such field peas may be included in diets for nursery pigs and growing-finishing pigs in amounts of at least 18 and 36%, respectively, without negatively affecting pig performance.     

青稞、荞麦、黍子、糜子、莜麦对于生长猪的营养价值评定

本研究旨在对青稞、荞麦、黍子、糜子和莜麦5种可在生长猪上应用的非常规谷物饲料原料进行营养价值评定。试验分别采集5种谷物原料样品,选取36头健康、体重为(32.1±4.2)kg的杜×长×大三元杂交去势公猪,随机分配到1个玉米-豆粕型基础日粮和5个非常规谷物饲料原料(替代基础日粮的40%～50%)的待测日粮处理中进行消化代谢试验,用全收粪尿法和套算法测定其对生长猪的全肠道表观消化能、代谢能以及总能和营养物质的表观全肠道消化率。结果表明:黍子、糜子有较高的淀粉含量,青稞和莜麦有较高的中性洗涤纤维和酸性洗涤纤维含量;干物质基础下,5种谷物原料的全肠道表观消化能和代谢能分别为15.97～17.87 MJ/kg和15.38～17.34 MJ/kg。     

Effects of exogenous enzyme supplementation to corn- and soybean meal-based or complex diets on growth performance, nutrient digestibility, and blood metabolites in growing pigs

Two experiments were conducted to determine the effects of dietary supplementation of exogenous enzymes on growth performance, apparent total tract digestibility (ATTD) of energy and nutrients, blood metabolites, fecal VFA, and fecal ammonia-N in growing pigs (Sus scrofa) fed a corn (Zea mays L.)- and soybean [Glycine max (L.) Merr.] meal (SBM)-based diet. In Exp. 1, 240 growing barrows (initial BW: 55.6 ± 0.9 kg) were randomly allotted to 5 treatments on the basis of BW. There were 4 replicates in each treatment with 12 pigs per replicate. The 5 treatments consisted of a corn-SBM-based control diet and 4 additional diets were similar to the control diet, with the exception that 0.05% β-mannanase (M), α-amylase + β-mannanase (AM), β-mannanase + protease (MPr), or α-amylase + β-mannanase + protease (AMP) was added to the diets, which were fed for 28 d. Pigs fed the AM, MPr, or AMP diet had greater (P < 0.05) ADG than pigs fed the control diet. Pigs fed the AMP diet also had greater (P < 0.05) ADG than pigs fed the M, AM, or MPr diet. Pigs fed the AMP diet had greater (P < 0.05) G:F than pigs fed the control diet. The G:F of the pigs fed the M, AM, or MPr diet were not different (P > 0.05) from the G:F in pigs fed the AMP or control diet. The ADFI, ATTD of nutrients, blood metabolites, and fecal VFA and ammonia-N concentrations were not different among treatments. In Exp. 2, 192 growing barrows (initial BW: 56.9 ± 1.0 kg) were allotted to 4 treatments. There were 4 replicates in each treatment with 12 pigs per replicate. Pigs were fed a corn-SBM-based diet (CSD) or a complex diet (CD) that contained corn, SBM, 3% rapeseed (Brassica napus L.) meal, 3% copra (Cocos nucifera L.) meal, and 3% palm (Elaeis guineensis Jacq.) kernel meal. Each diet was prepared without exogenous enzymes or with 0.05% AMP and all diets were fed for 28 d. The ADG and G:F of pigs fed the CSD were greater (P < 0.05) than pigs fed the CD. However, the type of diet had no effect on the ATTD of nutrients, blood metabolites, or fecal VFA and ammonia-N, and there was no diet × enzyme interaction for any of the measured variables. Supplementation of diets with exogenous enzymes resulted in greater (P < 0.05) ADG, G:F, ATTD of DM, GE, and CP, and blood urea nitrogen (BUN) concentration. These results indicate that supplementation of 0.05% of AMP enzymes to a corn-SBM diet or a complex diet may improve the performance of growing pigs.     

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 phytase supplementation to diets for weanling pigs on the digestibilities of crude protein, amino acids, and energy

Four experiments were conducted with weanling pigs fitted with a simple T-cannula at the distal ileum, to determine the effect of phytase supplementation to four diets on the apparent ileal digestibilities (AID) of CP and AA, and the apparent total-tract digestibilities (ATTD) of CP and DE. Phytase (Natuphos, DSM Food Specialties, Delft, The Netherlands) was supplemented at rates of 0, 500 or 1,000 FTU/kg to the four diets. A 20% CP (as-fed basis) corn-soybean meal diet was used in Exp. 1; a 20% CP wheat-soybean meal diet in Exp. 2; a 20% CP wheat-soybean meal-canola meal diet in Exp. 3; and a 19% CP barley-peas-canola meal diet in Exp. 4. In each experiment, six barrows, fitted with a simple T-cannula at the distal ileum, were fed the basal plus phytase-supplemented diets according to a repeated 3 x 3 Latin square design. Each experimental period comprised 14 d. The piglets were at fed 0800 and 2000 daily, equal amounts for each meal, at a daily rate of at least 2.4 times the maintenance requirement for ME. Feces were collected from 0800 on d 8 until 0800 on d 12 of each experimental period. Ileal digesta were collected from 0800 to 2000 on d 12, 13, and 14. Chromic oxide was used as the digestibility marker. The average initial and final BW (average of all experiments) were 7.9 and 16.5 kg, respectively. Phytase supplementation did not improve the AID of CP and AA in Exp. 1, 2, and 4; however, there were improvements (P < 0.05) or tendencies (P < 0.10) toward improvements in the AID of CP and AA or the ATTD of CP and the content of DE with phytase supplementation in Exp. 3. These results suggest that the AA response factor to microbial phytase supplementation depends on diet composition.     

Assessment of chromium tripicolinate supplementation and dietary energy level and source on growth, carcass, and blood criteria in growing pigs

Two experiments were conducted to evaluate potential interactive effects of supplemental Cr and dietary energy supply in growing pigs. Experiment 1 used 36 individually penned barrows, 25 to 65 kg, in a 2 x 3 factorial arrangement of supplemental Cr (0 or 200 ppb) and energy level (70, 80, or 90% of ME requirement). A corn-soybean meal basal diet was designed to supply all protein, mineral, and vitamin needs and 70% of the estimated ME need at 70% of ad libitum feed intake. Additional energy to 80% or 90% of the ME requirement was provided by a cornstarch/corn oil blend. In Exp. 2, 30 individually penned barrows, 23 to 68 kg, were used in a 2 x 4 factorial arrangement of supplemental Cr (0 or 200 ppb) and added energy source (none, cornstarch, corn oil, or choice white grease) with basal diets identical to Exp. 1. The various energy sources were added to 90% of the ME requirement. In both experiments, growth data were collected over a 50-d period and pigs were killed at 70.1 kg. Increasing energy levels increased (linear, P < 0.01) ADG, average backfat thickness, 10th rib backfat thickness, and cooler shrink and decreased (linear, P < 0.01) longissimus muscle area in Exp. 1. Carcass composition increased (linear, P < 0.01) in lipid and decreased in protein, water, and protein:lipid ratio in response to increasing ME levels. Similar results were observed in Exp. 2 in response to added energy, regardless of the energy source used. In response to ME, linear increases (P < 0.05) in plasma insulin concentration before feeding and after feeding were observed in Exp. 1. In Exp. 2, plasma insulin concentration was lower for the basal diet before feeding (P < 0.05) and higher for the starch diet after feeding (P < 0.01); insulin:glucose ratio increased (P < 0.01) after feeding for starch compared to oil and fat. No consistent effect of Cr or Cr x ME level on performance or carcass was observed (P > 0.10) in these experiments. Similarly, no Cr effect or Cr x ME interaction (P > 0.10) was observed in plasma glucose or insulin levels. Dietary energy levels markedly affected growth criteria in growing pigs (23 to 68 kg) in these experiments, as anticipated, but supplemental Cr was without effect on performance or carcass responses.