用绵羊小肠液冻干粉评定瘤胃非降解精饲料残渣的干物质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干物质于小肠的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0.5 g)与缓冲液种类(McDougall缓冲液与磷酸盐缓冲液)对12 h瘤胃非降解玉米与豆粕的干物质于小肠消化率的影响;第二个试验研究了缓冲夜pH值(7.0、7.5与8.0)与Ca2+浓度(340、680与2000μΜ)对12h瘤胃非降解玉米与豆粕的干物质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、12、15、18、21与24 h)对12h瘤胃非降解玉米与豆粕的干物质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干物质于小肠消化率的适宜条件为:0.45g小肠液冻干粉/0.56g饲料,McDougall缓冲液,pH=7.5,Ca2+=680μM,39℃,瘤胃非降解玉米与豆粕的最佳培养时间不同,分别为12与18h.     

用绵羊小肠液冻干粉测定饲料过瘤胃淀粉小肠消化率方法的研究

本试验旨在以玉米为样本筛选用绵羊小肠液冻干粉测定精饲料瘤胃非降解残渣淀粉小肠消化率的最佳培养条件。分别研究了小肠液冻干粉用量(0.2、0.3、0.4、0.5和0.6g)对16h玉米瘤胃非降解残渣干物质和淀粉小肠消化率的影响;离体培养时间(4、8、12、16、20和24h)对16h玉米瘤胃非降解残渣干物质和淀粉小肠消化率的影响。结果表明,在本试验条件下,绵羊小肠液冻干粉测定玉米瘤胃非降解残渣淀粉小肠消化率的最佳用量为0.45g小肠液冻干粉/0.56g玉米瘤胃非降解残渣,最佳培养时间为12h。利用绵羊小肠液冻干粉测定常用饲料过瘤胃残渣淀粉小肠消化率的方法是可行的。     

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     

用绵羊小肠液冻干粉评定瘤胃非降解精饲料残渣的干物质于小肠消化率方？…

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干物质于小肠的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１２ｈ瘤胃非降解玉米与豆粕的干物质于小肠消化率的影响；第二个试验研究了缓冲夜ｐＨ值（７．０、７．５与８．０）与Ｃａ＾２＋浓度（３４０、６８０与２０００μＭ）对化率的影     

绵羊小肠液冻干粉法测定常用饲料过瘤胃淀粉小肠消化率

试验用绵羊小肠液冻干粉法测定了常用饲料过瘤胃淀粉的小肠消化率。结果表明:所测6种饲料过瘤胃淀粉小肠消化率分别为玉米43.35%、麸皮19.48%、玉米淀粉57.79%、豆粕67.33%、麻粕50.19%、棉粕46.77%。     

肉牛常见饲料干物质和蛋白质瘤胃降解特性和小肠消化率研究

[方法]选用装有瘤胃瘘管和小肠瘘管的肉牛作为试验动物,尼龙袋法测定肉牛常见饲料干物质(DM)和粗蛋白(CP)的瘤胃降解特性和小肠消化率。[结果]结果表明,DM瘤胃有效降解率由高到低为玉米粉、麦麸、苜蓿干草、豆粕、菜籽粕、玉米青贮、醋糟、白酒糟;CP瘤胃有效降解率由高到低为苜蓿干草、麦麸、豆粕、醋糟、玉米粉、玉米青贮、菜籽粕、白酒糟;DM小肠消化率由高到低为豆粕、菜籽粕、玉米粉、白酒糟、醋糟、麦麸、苜蓿干草、玉米青贮;CP小肠消化率由高到低为豆粕、菜籽粕、玉米粉、苜蓿干草、麦麸、白酒糟、玉米青贮、醋糟。[结论]试验表明,不同饲料瘤胃降解特性不同,为小肠提供过瘤胃可消化蛋白的能力不同,且饲料的DM小肠消化率小于CP小肠消化率。     

移动尼龙袋法测定蛋白质饲料过瘤胃氨基酸的小肠消化率

试验测定了不同蛋白质饲料氨基酸的瘤胃降解率和瘤胃非降解残渣氨基酸的小肠消化率,旨在为建立饲料氨基酸小肠消化率数据库提供参考依据,以期指导日粮的配制。试验选用3头装有瘤胃瘘管和十二指肠瘘管的荷斯坦奶牛作为试验动物,采用瘤胃尼龙袋法和小肠尼龙袋法分别测定豆粕、葵花粕、芝麻粕、菜籽粕和棉粕的氨基酸含量、氨基酸的瘤胃降解率和小肠消化率。结果表明,不同的饲料过瘤胃氨基酸小肠消化率是不同的。同种饲料不同过瘤胃氨基酸的小肠消化率也不同。     

利用牛小肠液冻干粉法研究不同加工处理玉米瘤胃非降解残渣中干物质和淀粉的小肠消化率

牛小肠液冻干粉(BIF)法是一种常用的体外法,该法利用小肠中的各种酶研究营养物质的小肠消化情况,具有较好的稳定性和可重复性。本试验进行了BIF的制备、酶活性的检测及底物用量与培养时间的优化筛选,利用BIF研究不同加工处理(膨化、制粒、压扁、烘炒)玉米在泌乳奶牛瘤胃非降解残渣中干物质(DM)和淀粉的小肠消化率。结果表明,BIF的用量为0.5g/0.5g饲料,最佳培养时间为8h。膨化玉米组的DM和淀粉的小肠消化率显著高于颗粒玉米、烘炒玉米、压扁玉米及对照玉米组(P<0.05),其他组之间差异均不显著(P>0.05),这与瘤胃中的降解情况不同,可能与玉米的不同加工处理有关;各组DM和淀粉的小肠消化率之间比较,差异均不显著(P>0.05)。从BIF培养的结果来看,小肠消化率低于文献报道的小肠淀粉消化率,可能是BIF培养的底物为瘤胃未降解的残渣,与直接通过十二指肠灌注淀粉的组成有很大的差异。     

反刍家畜常用饲料蛋白质和氨基酸瘤胃降解特性和小肠消化率评定研究

本试验探讨了常用饲料在瘤胃的降解特性及非降解饲料的小肠消化率,旨在为研究反刍动物的营养平衡和消化规律及科学配制日粮提供依据。试验选用3头装瘤胃瘘管和十二指肠瘘管的肉牛,采用尼龙袋法研究反刍动物常用饲料粗蛋白质和氨基酸瘤胃降解参数和表观小肠消化率。结果表明,在本试验中粗蛋白质降解率由低到高的顺序为:酒糟蛋白、黄玉米、羊草、玉米胚芽饼、菜粕、棉粕、豆粕、花生饼、啤酒糟、苜蓿、米糠、小麦麸;总氨基酸瘤胃降解率由低至高的顺序依次为:酒糟蛋白、黄玉米、羊草、玉米胚芽饼、菜粕、豆粕、棉粕、啤酒糟、花生饼、苜蓿、米糠、小麦麸。除花生饼、酒糟蛋白和黄玉米外,粗蛋白质和总氨基酸的有效降解率差异不显著(P>0.05)。粗蛋白质的表观小肠消化率由低至高的顺序依次为:苜蓿、羊草、米糠、小麦麸、啤酒糟、玉米胚芽饼、棉粕、菜粕、玉米、酒糟蛋白、花生饼、豆粕;总氨基酸的小肠消化率由低至高的顺序依次为:羊草、苜蓿、米糠、小麦麸、啤酒糟、玉米胚芽饼、菜粕、棉粕、花生饼、玉米、酒糟蛋白、豆粕。由此可见,不同的饲料瘤胃降解特性是不同的,并且为小肠提供的各种可吸收氨基酸潜力也是不同的。     

不同产地豆粕和DDGS营养成分、瘤胃降解率及小肠消化率的分析测定

试验研究了不同产地(吉林、九三、林口)豆粕(SBM)和不同产地(集贤、牡丹江、肇东)玉米酒精糟(DDGS)营养成分、CP的瘤胃降解规律及RUP的小肠消化率。试验选用3头装有永久性瘤胃瘘管的干奶期中国荷斯坦奶牛,利用尼龙袋原位培养法研究不同产地豆粕和DDGS在奶牛瘤胃中CP的降解规律。每个尼龙袋每种饲料装5 g,在瘤胃中培养0、2、4、8、16、24和48 h。将每个尼龙袋每种饲料装75 g瘤胃培养16 h,瘤胃未降解残渣强饲给公鸡,从而测定豆粕和DDGS的IDP。吉林豆粕中的CP和SP含量最高,林口豆粕最低,而九三豆粕居中。林口豆粕中NDIP和ADIP含量为29.10%和2.52%,在三种豆粕中处于最高。三种DDGS的CP、NDIP和ADIP含量的变化趋势一致,均为肇东地区最高,其次为集贤、牡丹江。除了慢速降解部分(b)的降解速率(c)外,豆粕和DDGS的其它降解参数均差异不显著。九三豆粕IDP为73.37%,显著高于其它两种豆粕(P<0.05)。集贤DDGS的IDP显著高于牡丹江DDGS(P<0.05),而肇东DDGS居中。由此得出结论,除了营养指标受到产地影响外,豆粕和DDGS的瘤胃降解率和小肠消化率均不受产地影响。     

鸡体内小肠液和模拟小肠液对饲料蛋白质消化的比较研究

本试验旨在比较鸡体内小肠液(ESIF)和模拟小肠液(SSIF)对饲料蛋白质进行仿生消化后残渣中蛋白质分解产物片段分布的差异.采用两样本比较试验设计,其中小肠液分别为ESIF和SSIF,以豆粕、棉籽粕、菜籽粕、玉米蛋白粉和酪蛋白为蛋白质饲料原料的代表性底物.在单胃动物仿生消化系统中,以2种小肠液对每个饲料原料进行仿生消化...     

Ruminal protein metabolism and intestinal amino acid utilization as affected by dietary protein and carbohydrate sources in sheep.

Eight wether lambs fitted with ruminal, duodenal, and ileal cannulas were used in a replicated 4 x 4 Latin square design to study the effects of carbohydrate and protein sources on ruminal protein metabolism and carbohydrate fermentation and intestinal amino acid (AA) absorption. Treatments were arranged as a 2 x 2 factorial. Carbohydrate sources were corn and barley; protein sources were soybean meal (SBM) and fish meal (FM). Diets contained 15.5% CP, of which 40% was supplied by SBM or FM. Corn or barley provided 39% of dietary DM that contained equal amounts of grass hay and wheat straw. Fish meal diets produced a lower (P less than .05) ruminal NH3 concentration and resulted in less CP degradation and bacterial protein flow to the duodenum than did SBM diets. Replacing SBM with FM increased (P less than .05) ruminal digestion of all fiber fractions. In addition, cellulose and hemicellulose digestibilities in the rumen tended to increase (P greater than .05) when barley replaced corn in the FM diets. Carbohydrate x protein interactions (P less than .05) were observed for OM digestion in the rumen and AA absorption in the small intestine (percentage of AA entering); these interactions were highest for the barley-FM diet. These results suggest that feeding FM with barley, which is high in both degradable carbohydrate and protein, might benefit ruminants more than feeding FM with corn, which is high in degradable carbohydrate but relatively low in degradable protein.     

蛋白质饲料经瘤胃培养和小肠酶降解后的氨基酸模型

以 3头瘘管牛用尼龙袋法测定鱼粉、菜籽粕、棉仁粕和胡麻粕经瘤胃培养后和小肠酶降解后的氨基酸模型。经瘤胃培养后 ,饲料中的 3种支链氨基酸和苯丙氨酸占总氨基酸比例增加 ,其它氨基酸基本保持原样中的比例。瘤胃培养 2 4h未降解残渣用小肠复合酶处理 ,胱氨酸、缬氨酸、亮氨酸、异亮氨酸和赖氨酸及精氨酸在氨基酸模型中的比例增加。而谷氨酸和天冬氨酸比例下降 ,其它氨基酸基本保持处理前的模型     

Site of protein digestion in steers: predictability

The nature and predictability of protein digestion in steers were examined in a series of experiments. Bypass and intestinal digestion of supplemental proteins were measured with Angus steers (203 to 254 kg) fitted with dual reentrant intestinal cannulas. Daily feed intakes were 1.8 to 1.9% of body weight. Two trials were conducted with soybean meal, cottonseed meal, a hardened casein, meat meal and two different sources of dehydrated alfalfa meal fed with an 80% concentrate diet. In the third trial, digestion of soybean meal and cottonseed meal were measured with a 60% prairie hay diet. Estimates of ruminal escape or bypass were 43, 50, 36, 76, 57, 62, 24 and 43%, respectively. Results suggest that roughage level alters bypass. A standard reference system for predicting bypass based on measurements of N solubility and in situ disappearance rates was compared with measured bypass. The correlation between observed bypass to the small intestine and bypass predicted by this system was high (r = .91, P less than .01). Combining pepsin solubility, an indicator of true intestinal digestibility, with bypass estimated by the standard reference system, allowed us to predict N disappearance from the small intestine. Predicted and measured N disappearance of fed N from the small intestine were very close.     

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

ABSTRACT: 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.     

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.     

Evaluation of dairy food processing wash water solids as a protein source: III. Nitrogen utilization by heifers fed medium-concentrate diets

Eight multicannulated heifers (average BW 415 +/- 34 kg) were used in a replicated 4 x 4 Latin square to evaluate fluid milk processing wash water solids (WWS) as a dietary N source. Heifers were fed corn/cottonseed hull-based diets containing soybean meal (control, 0% WWS N) or WWS replacing soybean meal at 33, 67, or 100% of supplemental dietary N. Total tract and ruminal DM and OM digestibilities decreased linearly or cubically (P less than .05) as dietary WWS N increased. Total ruminal VFA concentration (P less than .05) and propionic acid molar proportion (P less than .10) were greater in heifers fed 0 vs 100% WWS N. Heifers fed 0% WWS N had the greatest (P less than .05) ruminal ammonia concentration at all sampling times. Dietary WWS did not affect (P greater than .10) ruminal pH, fluid dilution rate, fluid flow, fluid volume, or turnover time. Total tract N digestibility decreased quadratically (P less than .10) with increasing WWS N in the diet. Supplemental WWS N did not affect (P greater than .10) flow of duodenal ammonia N or bacterial N, or efficiency of microbial N synthesis. Diets containing WWS N resulted in a cubic increase (P less than .10) in duodenal flow of essential amino acids compared with 0% WWS N; however, there were no differences in small intestinal amino acid disappearance. Data indicate that WWS can replace 33% of the soybean meal N in a corn/cottonseed hull-based diet without decreasing ruminal fermentation, fluid digesta kinetics, microbial efficiency, or small intestinal amino acid utilization.