In Vitro assessment of the nutritive value of expanded soybean meal for dairy cattle

Little information is available about the nutritive value of expanded soybean meal, which is produced by expansion of soybeans prior to solvent extraction of the oil. During processing, expanded soybean meal is subjected to additional heat, which might increase the concentration of ruminally undegraded protein. Processing of soybeans with heat during oil extraction could affect lysine availability by increasing ruminally undegraded protein or by impairing intestinal digestion. Our objective was to compare solvent and expanded soybeans with regard to chemical composition and nutritive value for dairy cattle. Samples of expanded soybean meal (n = 14) and solvent- extracted soybean meal (n = 5) were obtained from People’s Republic of China to study effects of the expansion process on nutritive value for dairy cattle. Solvent-extracted soybean meal (n = 2) and mechanically extracted (heated) soybean meal (n = 2) from the United States served as references for comparison. Samples were analyzed for crude fat, long-chain fatty acids, crude protein, amino acids, chemically available lysine, in situ ruminal protein degradation, and in vitro intestinal digestibility. No differences were found between solvent-extracted soybean meals from China and expanded soybean meals from China for crude fat, crude protein, amino acids, or chemically available lysine. In situ disappearance of nitrogen, ruminally undegraded protein content, and in vitro intestinal digestion of the ruminally undegraded protein were generally similar between solvent-extracted soybean meals made in China and expanded soybean meals made in China; variation among soybean meals was small. Results indicate that the additional heat from the expansion process was not great enough to affect the nutritive value of soybean meal protein for ruminants. Although expansion may improve the oil extraction process, the impact on the resulting soybean meal is minimal and does not require consideration when formulating ruminant diets.     

68个去皮和带皮豆粕的氨基酸组成及其回归估测

采集美国、巴西、中国加工的11个去皮豆粕和中国13个省市的51个大、中、小型企业加工的57个带皮豆粕,对其必需氨基酸组成进行比较研究。结果显示:去皮豆粕优于带皮豆粕。去皮豆粕的赖氨酸(88%干物质基础)为3.08%,比带皮豆粕高0.09%P(<0.01);其它氨基酸如Ile、Lys、Met、Phe、Cys和总必需氨基酸(P<0.01),Leu、Thr和V alP(<0.05)的含量均高于带皮豆粕。本次研究建立了以豆粕中粗蛋白质含量为自变量估测豆粕中必需氨基酸含量的有效方程;Lys、Thr、Trp、Met+Cys和Arg的回归估测值与实测值的差异较小,差异度分别为0.95%、0.30%和-2.19%;通过豆粕粗蛋白质含量回归估测Lys、Thr和Arg含量是可行的。     

Nutritive Value of Four Soybean Products in Diets for Atlantic Salmon (Salmo salar,L.)

Abstract

Four processed soybean products were evaluated as protein sources for Atlantic salmon: solvent-extracted soybean meal (SBM44), dehulled and solvent-extracted soybean meal (SBM50), dehulled full-fat soybean meal (FFSBM) and soybean concentrate (SBC). The soybean products replaced high-quality fish meal at levels corresponding to 0, 14, 28, 42 and 56% soybean protein of total protein.

Dietary inclusion of SBC, at the expense of fish meal, did not affect weight gain, carcass lipids, fecal excretion of nutrients or fecal dry matter content significantly. The nutritive value of the SBC protein appeared comparable to that of the fish meal. The three other soybean products impaired performance increasingly with increasing levels of inclusion, indicating lower nutritive value than for the fish meal. The favourable results seen with SBC indicated a great potential of soybean to become an important protein source for Atlantic salmon through improved processing.     

Amino acid profile of escaped feed protein after rumen incubation and their intestinal digestibility.

The crude protein content and amino acid profile of seven feedstuffs (linseed meal, maize gluten meal, rapeseed meal, rapeseed meal protected, soybean meal, fullfat soybean extruded and sunflower meal) were determined before and after ruminal incubation for 16 h in three bulls with large rumen cannulas. The intestinal disappearance of amino acids was measured using mobile bag technique. Ruminal incubation affected amino acid profile of all experimental feedstuffs. Crude protein degradation varied from 29.3% for maize gluten meal to 86.4% for rapeseed meal. A tendency towards increased disappearance was observed for glutamic acid, histidine, lysine and proline and decreased disappearance for branched-chain amino acids. The intestinal crude protein digestibility was higher than > 80%, except rapeseed meal (66.4%) and sunflower meal (77.8%). The least digestible individual amino acids were methionine and isoleucine in rapeseed meal, histidine and methionine in rapeseed meal protected and arginine in sunflower meal. In general, the lowest amino acid digestibilities were found in feedstuffs with the highest fibre content. The feedstuffs show that they have different potential for supplying of limiting amino acids. Of particular value are the feedstuffs with low crude protein degradability in the rumen and high intestinal digestibility of amino acids.     

Apparent digestibility of amino acids in raw and heated conventional and low-trypsin-inhibitor soybeans for pigs.

An experiment was conducted with ileally cannulated pigs to determine the apparent digestibility of amino acids and N in raw or heated conventional or low-trypsin-inhibitor soybeans. Six littermate barrows initially averaging 24 kg were fed cornstarch-based diets (10.5% CP, .68% lysine, 3,558 kcal of ME/kg) supplemented with raw (unheated), conventional soybeans; raw, low-trypsin-inhibitor soybeans; heated, conventional soybeans; heated, low-trypsin-inhibitor soybeans; or solvent-extracted soybean meal. Heating was achieved by autoclaving soybeans (after grinding) for 20 min at 110 degrees C. The urease activities of the two raw soybean sources were similar, but the trypsin inhibitor activity of the raw, low-trypsin-inhibitor soybeans was about one-half that of the raw, conventional soybeans. The lower trypsin inhibitor activity of the raw, low-trypsin-inhibitor soybeans was associated with an improvement in the apparent digestibility of amino acids and N compared with the raw, conventional soybeans (P less than .05). Heating reduced the urease and trypsin inhibitor activities and improved (P less than .05) the apparent digestibility of amino acids and N in both types of soybeans. However, the heated, conventional soybeans contained more trypsin inhibitor activity than the heated, low-trypsin-inhibitor soybeans and the digestibilities of the amino acids were lower (P less than .05). Although the urease and trypsin inhibitor activities of the two heated soybean sources were similar to or less than those of soybean meal, the digestibilities of amino acids were not as great (P less than .05) in the heated soybeans as in soybean meal.(ABSTRACT TRUNCATED AT 250 WORDS)     

以常规成分为变量估测饲料中必需氨基酸含量的初步探讨

本文探讨了玉米、小麦、高粱、豆饼(粕)、菜籽饼(粕)、花生饼(粕)、国产鱼粉、小麦麸、米糠、米糠饼、米糠粕、苜蓿草粉、大豆、黑大豆、蚕豆、豌豆的粗蛋白、粗纤维、粗脂肪和粗灰分与必需氨基酸的多元回归方程和粗蛋白与必需氨基酸之间的一元回归方程。一元回归方程估测误差(RSD)略高于多元回归方裎估测误差,但相关程度两者基本一致。方差分析表明,玉米、小麦、花生饼(粕)、国产鱼粉、小麦麸、米糠、苜蓿草粉、黑大豆、大豆、蚕豆、豌豆的常规成分与必需氨基酸含量存在显著的相关关系(P<0.05);大麦、高粱、米糠饼(粕)和菜籽饼(粕)常规成分与苯丙氨酸、组氧酸、精氨酸等必需氨基酸存在显著扣关关系(P<0.05),与赖氨酸、亮氨酸、蛋氨酸等必需氨基酸不存在相关关系(P>0.05);豆饼(粕)常规成分与必需氨基酸不存在相关关系。利用朱参加计算的玉米和小麦麸样品数据资料比较了粗蛋白与必需氨基酸之间的一元回归方程估测值、按粗蛋白递增比例计算值和实测值之间的差异。表明用回归方程估测较按粗蛋白质递增比例推算,更接近于实际测定值,具有显著相关关系的回归方程应用于生产以估测某些必需氨基酸含量是可行的。     

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.     

Regional and processor variation in the ileal digestible amino acid content of soybean meals measured in growing swine

To assess differences in soybean meal quality related to region of production, researchers in Illinois, Kansas, North Carolina, The Netherlands, and Ohio collected four soybean meal samples processed locally at least 15 d apart. These samples were assayed for ileal amino acid digestibility by pigs using a common soybean meal and a soy protein concentrate as references, and a low-protein casein diet for determination of endogenous amino acid losses. Digestibility was determined at each university using seven barrows surgically fitted with ileal cannulas in a 7 x 7 Latin square design. The experimental diets contained 17% CP from the test material except for the low-protein casein diet. Animals were fed twice daily, 12 h apart, at a level of 45 g x kg(-0.75) BW for each meal. Following a 5-d adaptation period, ileal digesta were collected for two 12-h periods for 2 d to be used for determination of ileal digestibility. Variation in amino acid digestibility was very small among and within sites and was much smaller than variation in the concentration of amino acids. Among sites, samples from The Netherlands had less total and thus digestible lysine and methionine than the U.S. samples (P < 0.05). The soybean meals tested in this experiment were approximately 4% higher in amino acids than that reported in the NRC (1998). True (standardized) digestibilities, however, were very similar to NRC values except for cysteine and threonine, which were 5 and 3 percentage points lower in this experiment, respectively. In conclusion, soybeans grown in the United States and locally processed into soybean meal were very similar in nutritional composition. Soybean meals produced in The Netherlands were lower in lysine and methionine (P < 0.05) but had a digestibility similar to that produced in the United States.     

瘤胃尼龙袋法测定饼粕饲料总氨基酸降解率

以3头带瘤胃瘘管肉牛用尼龙袋法对大豆、向日葵粕、花生粕、豆粕、棉仁粕、菜籽粕、鱼粉等7种饲料的瘤胃总氨基酸降解率进行了比较研究 ,其总氨基酸的瘤胃降解率分别为74.55 % ,81.99 % ,40.69 % ,32.87 % ,41.08 % ,35.73 % ,30.60 % ;粗蛋白降解率(X)与总氨基酸降解率(Y)显著相关(Y= -1.90+1.01X(r=0.996,n=7,P<0.01)。不同时间点瘤胃降解残渣中氨基酸占总氨基酸的比例与饲料原样中氨基酸占总氨基酸的比例 ,在瘤胃降解初期相关性较好 ,随瘤胃降解时间延长相关性下降。     

Effects of different heat treatments during processing on nutrient digestibility of soybean meal in growing swine

Four soybean meals (SBM) were prepared in a commercial solvent-extraction plant to give a much wider range in heat treatment than is usually found among commercially available SBM. The meals were designated in ascending order of heat treatment as Under, Normal, Over and Rumen Escape. The Normal meal was processed using standard operating conditions. The Under meal received less heat treatment by reducing the steam pressure and retention time in the desolventizer-toaster. Over and Rumen Escape meals received further heat treatment in an additional four-compartment toaster. The Over meal received less heat treatment than the Rumen Escape meal by reducing steam pressure and retention time in both toasters. Crude protein content was similar for the four meals, but lysine tended to decrease with increasing heat treatment. In general, urease activity, trypsin inhibitor, protein dispersibility index and nitrogen solubility index decreased with increasing heat treatment. The +a Hunterlab color values increased as heat treatment increased. Apparent ileal digestibility of N and amino acids were similar for all meals (P greater than .05); however lysine digestibility for the Rumen Escape meal was 3.3 percentage units lower than the average of the lesser-heated meals. Energy digestibilities and nitrogen balance data were also similar (P greater than .05) for the four meals, but the apparent biological value of the Rumen Escape meal was 4.5 percentage units lower than the average of the other meals. There were no differences in nutritional value among the Under, Normal and Over meals, which represent the range in heat treatment usually found among SBM. The Rumen Escape meal, which received more severe heat treatment, tended to have lower nutritional value than the lesser-heated meals.     

棉粕与豆粕在反刍动物瘤胃内降解动力学的评定分析

本试验旨在评定棉粕与豆粕的干物质（DM）、有机物（OM）、粗蛋白质（CP）在绵羊瘤胃内的降解动力学参数变化及瘤胃降解前后有效赖氨酸的含量变化。选用3只安装有永久性瘤胃瘘管的体重为（28.0±2.97）kg的育肥哈萨克公羊,代谢笼内单笼饲喂,每天饲喂棉籽壳200 g、精料500 g、小麦秸500 g,余料不超过10%。采用尼龙袋技术评定棉粕与豆粕DM、OM及CP的降解动力学参数,计算有效降解率（ED）及瘤胃停留时间（RRT）,染料结合法（DBL）测定有效赖氨酸的含量。结果表明,在瘤胃固相食糜的平均外流速度为1.84%/h条件下,豆粕DM、OM及CP的瘤胃降解率及有效降解率均高于棉粕,而瘤胃停留时间均短于棉粕。豆粕经瘤胃内培养16 h后有效赖氨酸含量略有升高,而棉粕无明显变化。该试验结果为进一步评定棉粕及豆粕养分的小肠消化率提供参考。     

不同温度挤压膨化全脂大豆对肉仔鸡生产性能和养分利用率的影响

为评定膨化全脂大豆的营养价值及膨化加工的适宜条件参数,用肉仔鸡进行了为期４９天的饲养试验和一个预试及正试期各３天的交叉代谢试验。饲养试验选用４０４只１日龄哈巴德母系公雏肉仔鸡,分成４组,每组１０１只。以豆粕＋豆油日粮为对照,分别用北京建中机器厂“Ｂ９９－１”干法挤压膨化机生产的１３０、１４０和１５０℃膨化全脂大豆替代对照日粮中部分豆粕和全部豆油。于饲养试验的第４２天在每个处理中选４笼鸡进行代谢试验,喂给与饲养试验相同的日粮,用全收粪法测定养分消化率。结果表明,在螺旋转速为４５０～５５０ｒｐｍ、大豆水分为１３．１％时,“Ｂ９９－１”膨化机对全脂大豆的适宜膨化温度为１４０～１５０℃。在此条件下,用膨化全脂大豆替代日粮中部分豆粕和全部豆油,可使肉仔鸡全程日增重提高１．９％～２．３％,饲料转化率提高３．４％～４．４％（Ｐ＜０．０５）,氮表观消化率提高４．５％～５．１％,脂肪表观消化率提高５．３％（Ｐ＜０．０５）～５．８％（Ｐ＜０．０５）,日粮部分氨基酸利用率略有改善。     

用绵羊小肠液冻干粉评定瘤胃非降解精饲料残渣的有机物于小肠消化率方法的研究

本试验旨在筛选用绵羊小肠液冻干粉评定瘤胃非降解精饲料残渣的有机物于小肠消化率的最佳培养条件。试验包括三部分 :第一个试验研究了小肠液冻干粉用量 ( 0 .2、0 .3、0 .4与 0 .5g)与缓冲液种类(McDougall缓冲液与磷酸盐缓冲液 )对 1 2h瘤胃非降解玉米与豆粕的有机物于小肠消化率的影响 ;第二个试验研究了缓冲液pH值 ( 7.0、7.5与 8.0 )与Ca2 + 浓度 ( 3 4 0、680与 2 0 0 0 μmol/L)对 1 2h瘤胃非降解玉米与豆粕的有机物于小肠消化率的影响 ;第三个试验研究了离体培养时间 ( 3、6、9、1 2、1 5、1 8、2 1与 2 4h)对1 2h瘤胃非降解玉米与豆粕的有机物于小肠消化率的影响。筛选的用绵羊小肠液冻干粉评定瘤胃非降解精饲料残渣的有机物于小肠消化率的适宜条件为 :0 .4 5g小肠液冻干粉 / 0 .56g饲料 ,McDougall缓冲液 ,pH =7.5,Ca2 + =680 μmol/L ,3 9℃ ,瘤胃非降解玉米与豆粕的最佳培养时间不同 ,分别为 1 2与 1 8h     

Soybean meal from roundup ready or conventional soybeans in diets for growing-finishing swine

Dehulled soybean meal prepared from genetically modified, herbicide (glyphosate)-tolerant Roundup Ready soybeans containing the CP4 EPSPS protein and near-isogenic conventional soybeans were assessed in an experiment with growing-finishing pigs. The soybeans were grown in the yr 2000 under similar agronomic conditions except that the Roundup Ready soybeans were sprayed with Roundup herbicide. Both were processed at the same plant. The composition of the two types of soybeans and the processed soybean meal were similar. Corn-soybean meal diets containing conventional or Roundup Ready soybean meal and fortified with minerals and vitamins were fed to 100 cross-bred pigs from 24 to 111 kg BW. Diets contained approximately 0.95% lysine initially and were reduced to 0.80 and 0.65% lysine when pigs reached 55 and 87 kg BW, respectively. There were 10 pens (five pens of barrows and five pens of gilts) per treatment with five pigs per pen. All pigs were scanned at 107 kg mean BW and all barrows were killed at the end of the test for carcass measurements and tissue collection. Rate and efficiency of weight gain, scanned backfat and longissimus area, and calculated carcass lean percentage were not different (P > 0.05) for pigs fed diets containing conventional or Roundup Ready soybean meal. Gilts gained slower, but they were more efficient and leaner (P < 0.05) than barrows. Responses to the type of soybean meal were similar for the two sexes with no evidence of a diet x sex interaction for any of the traits. In most instances, carcass traits of barrows were similar for the two types of soybean meal. Longissimus muscle samples from barrows fed conventional soybean meal tended (P = 0.06) to have less fat than those fed Roundup Ready soybean meal, but water, protein, and ash were similar. Sensory scores of cooked longissimus muscles were not influenced (P > 0.05) by diet. The results indicate that Roundup Ready soybean meal is essentially equivalent in composition and nutritional value to conventional soybean meal for growing-finishing pigs.     

中国双低油菜饼粕与加拿大卡诺拉粕品质特性的化学评价

系统地评价了 3个中国双低油菜与加拿大卡诺拉的商品饼粕与脱脂种籽的蛋白质、氨基酸、蔗糖、寡聚糖、饲粮总纤维和灰分等化学特性 ,并对饲粮总纤维的构成成分及加工的影响进行了研究。饲粮总纤维由非淀粉多糖、木质素和多酚、细胞壁蛋白质和矿物质组成。 3个中国双低菜粕的粗蛋白、蔗糖及必需氨基酸含量均接近或高于卡诺拉帕 ,但饲粮总纤维含量显著不同 ,尤其是蛋白质含量由于加工方式不同变异极大。在试验室条件下加工的脱脂种籽样品与相应的饼粕样品相比 ,蔗糖、赖氨酸和饲粮纤维含量变化显著。因此 ,改进双低油菜的加工技术是提高饼粕质量的关键     

The effect of different high levels of soy extract pellets in the ration on the digestibility of crude nutrients, basic and sulfur-containing amino acids of wheat in colostomized laying hybrids

In two digestibility experiments with 4 colostomized laying hybrids each, the influence of 12.5% (ration 1) and 25% soybean meal (ration 2) on the digestibility of the crude nutrients, the basic and sulphur-containing amino acids in the wheat rations was tested. In ration 1 the digestibility of the crude protein was 84.9%, of the crude fat 56.6% and that of the N-free extractives 87.4%; for ration 2 the values were 83.6%, 47.4% and 82.5%. The digestibility values for wheat acquired with the difference method for ration 1 were 85.7% for crude protein, 57.0% for crude fat and 89.8% for N-free extractives; energy concentration was 766 EFUhens. For wheat supplemented with 25% soybean meal the same digestibility value of the crude protein could be ascertained, the digestibility of the crude fat and the N-free extractives, however, was lower than for ration 1 so that an energy concentration lower by 3.9% was calculated. The possible causes of the influence of the different levels of lysine and thioamino acids on the digestibility of these amino acids of wheat are described.     

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.     

Effects of different heat treatments during processing of soybean meal on nursery and growing pig performance

Four soybean meals (SBM) were manufactured in a commercial solvent-extraction plant to give a much wider range in heat treatment than is usually found among commercially available SBM. The SBM were designated in ascending order of heat treatment as Under, Normal, Over and Rumen Escape. The nutritive value of the four meals was evaluated in a series of five feeding trials using 458 pigs: two performance and two diet preference trials with pigs weaned at 4 wk of age and one performance trial with growing pigs (17.4 kg initial weight were conducted). In both nursery and grower trials, there were no differences (P greater than .10) in performance of pigs fed the four meals. However, in the nursery trials, the severely heated meal (Rumen Escape) supported slightly lower gains (6.4%) and less desirable feed efficiency (3.5%) than the average of the other three meals. Growing pig performance was essentially the same for all meals. This suggests that older pigs either used the Rumen Escape meal more effectively than nursery pigs, or the Rumen Escape diet contained adequate digestible lysine for 17.4-kg pigs to grow optimally. In the preference studies, pigs selected between Normal- and Rumen Escape-supplemented diets. Pigs consumed 63 and 62% of the Normal diet in preference trials 1 and 2, but these differences were not significant (P greater than .10) due to the large variation among pens. These data suggest that the range of heat treatment normally found among commercially available SBM (Under, Normal and Over meals) has no effect on the nutritive value of the meal for swine.(ABSTRACT TRUNCATED AT 250 WORDS)     

蒸煮酶解羽毛粉的营养价值及其在肉鸭上的能量和氨基酸利用率评定

本试验旨在研究采用真代谢能(TME)法评定3种蒸煮酶解羽毛粉对于肉鸭的能量和氨基酸营养价值,为合理开发和利用羽毛粉蛋白质资源提供基础数据。3种羽毛粉(Ⅰ~Ⅲ)分别为42日龄樱桃谷肉鸭羽毛粉、550日龄罗曼蛋鸡羽毛粉和100日龄三黄肉鸡羽毛粉。试验选取20只7周龄樱桃谷肉鸭,随机分为4个处理,每个处理5个重复,每个重复1只肉鸭,单笼饲养。处理1(T1)为测定羽毛粉Ⅰ,处理2(T2)为测定羽毛粉Ⅱ,处理3(T3)为测定羽毛粉Ⅲ,处理4(T4)为饥饿处理。试验期为7 d。结果表明:1)以干物质(DM)为基础,羽毛粉Ⅰ、Ⅱ、Ⅲ的总能(GE)分别为21.31、21.02和20.18 MJ/kg,表观代谢能(AME)分别为13.71、12.29和12.10 k J/kg,TM E分别为14.83、13.42和13.22 M J/kg。2)以DM为基础,羽毛粉Ⅰ、Ⅱ、Ⅲ的粗蛋白质(CP)含量分别为91.05%、87.31%和91.06%;羽毛粉Ⅰ、Ⅱ、Ⅲ的总氨基酸(TAA)含量都在80%以上,但不同羽毛粉的氨基酸含量差异较大。3)羽毛粉Ⅰ、Ⅱ、Ⅲ的TAA表观可代谢率分别为81.51%、73.07%和76.85%,TAA真可代谢率分别为85.09%、76.89%和80.43%。3种羽毛粉的表观可利用氨基酸和真可利用氨基酸含量也存在显著差异(P0.05)。由此可见,利用TM E法测定毛粉能量与氨基酸的营养价值,发现3种羽毛粉的代谢能(M E)、表观可利用氨基酸和真可利用氨基酸存在明显差异。羽毛粉Ⅰ的GE、ME、CP及TAA代谢率均高于羽毛粉Ⅱ和羽毛粉Ⅲ。     

Growth performance and metabolic efficiency in Nile tilapia (Oreochromis niloticus L.) fed on a diet containing Jatropha platyphylla kernel meal as a protein source

Jatropha platyphylla is available on the pacific coast from Sinaloa to Michoacán including the Nayarit and Jalisco states in Mexico. The seeds of J. platyphylla are rich in oil and protein, and the kernel meal (JPKM) prepared after oil extraction contains 70-75% crude protein (CP). Contents of essential amino acids (except lysine) are higher in JPKM than in soybean meal (SBM). Phorbol-esters, the main toxin present in most Jatropha species is absent in J. platyphylla. Heat-treated JPKM (H-JPKM) was evaluated as a protein supplement in tilapia feed and compared with that of SBM and fish meal (FM). Nile tilapia (Oreochromis niloticus L.) fingerlings (15 fish; av. body mass 13.9 ± 0.17 g) were randomly distributed in three groups with five replicates each. A 12-week experiment was conducted in a respirometer system to evaluate the growth performance, nutrient utilization and energy budget. Nile tilapia fingerlings were fed three iso-nitrogenous diets (36% CP): Control containing FM, and Jatropha and Soybean diets in which 62.5% of FM protein was replaced by H-JPKM and SBM respectively. The growth performance, feed conversion ratio, protein efficiency ratio, apparent lipid conversion and energy retention did not differ significantly among the three groups. Higher protein productive value was observed in plant protein fed groups. Average metabolic rate, energy expenditure per g protein fed and retained in the body did not differ significantly among the three groups. Conclusively, Nile tilapia fed plant protein (heated JPKM and SBM) and FM protein-based diets exhibited equal average metabolic rate which indicate that JPKM can be used as a protein source in aqua feed.