差量法测定猪回肠AA的真消化率及内源AA的排泄量

本文探讨了采用差量法测定猪对豆粕氨基酸(AA)的消化率和内源氨基酸排泄量的可行性.试验测得豆粕在16%、10%日粮蛋白水平上的表观氨基酸消化率分别为81.84%、78.59%,以差量法求得真消化率为87.87%.研究结果表明,差量法可以作为测定猪氨基酸真消化率和内源氨基酸排泄量的新方法.     

大米粉的猪回肠氨基酸真消化率测定

大米加工副产品大米粉长期以来被添加到米糠中利用，显著降低了其利用率。本试验用三头施以回直肠吻合术猪，采用单因子设计，以大米粉为半纯合日粮，无氮日粮由醋酸纤维素提供粗纤维来测定内源值，测定了大米粉的猪回肠末端氨基酸表观消化率和真消化率。大米粉的回肠末端氨基酸的表观消化率的平均值为76．20％，真消化率的平均值为85.86％。这些数据可为我国氨基酸消化率数据库提供参考，并且可作为以可消化氨基酸为基础配制日粮时的依据。     

The Rumen Degradation Characteristics of Whole Sugarcane for Dairy Cows and Its Application in Substituting Alfalfa,Oat Hay and Concentrate in Dairy Cows' Diets

The purpose of this experiment was to investigate the rumen degradation characteristics of whole sugarcane of dairy cows and its effects of using it replacing alfalfa, oat hay and concentrates in dairy cows' diet on the rumen fermentation, nutrient apparent digestibility, blood biochemical indexes and production performance of dairy cows, in order to open up new ways to replace the increasing prices feedstuff such as alfalfa, oat hay and concentrate in dairy cows' diets with whole sugarcane. In experiment one, the in-situ test, namely the rumen nylon bag test was used to investigate the rumen degradation characteristics of various nutrients of whole sugarcane, leymus chinensis and alfalfa. Experiment two was in vivo test,repeat 3 ⅹ 3 Latin square design was conducted and Holstein dairy cows with similar body weight, parities and milk yield and permanent rumen fistula were chosen to investigate the effect of using whole sugarcane replacing 25% or 50% of imported alfalfa from the Unites States in dairy cows' diet on nutrient digestibility, rumen fermentation characteristics and blood biochemical indexes of dairy cows. In experiment three, 60 Holstein dairy cows with similar parity, milk yield and milk in lactation were selected to perform production test, which aimed to explore the effects of using whole sugarcane replacing 30% alfalfa hay, 50% oat hay or 10% concentrate on the production performance, blood biochemical indexes of dairy cows and the economic benefits of dairy farms. The results showed that：1) The effective degradation rates of dry matter (DM) and acid detergent fiber (ADF) of whole sugarcane were significantly higher than leymus chinensis (P<0.05), and the effective degradation rates of neutral detergent fiber (NDF) and organic matter (OM) were significantly higher than leymus chinensis and alfalfa (P<0.05). 2) There was no significant effect on rumen pH, NH₃-N (except 25% group at the 4 h time point) and volatile fatty acid (VFA) concentrations of dairy cows when using 25% and 50% whole sugarcane to replace imported alfalfa from the Unites States in the diet. There was also no significant effect on DMI and digestibility of DM, CP, OM and ADF, while the digestibility of NDF in the 50% group was significantly increased (P<0.05). In 50% group, the content of serum urea nitrogen in 2 and 8 h was significantly lower than 25% group and control group (P<0.05) and there was no significant difference in the blood content of β-hydroxybutyric acid, rumen VFA and total VFA in each group at different time points. 3) After using 50%, 30% and 10% of whole sugarcane to replace oat hay, alfalfa hay and concentrate, respectively, no significant difference was detected in blood glucose, urea nitrogen, β-hydroxybutyric acid, the esterification of fatty acid (NEFA), and milk yield. Besides, combined with milk yield and feed cost, the economic benefits of each cow in the substitution groups increased by 3.28, 7.48 and 1.62 yuan per day. respectively, compared with control group. It can be seen that the whole sugarcane is a kind of high-quality roughage that can be used by dairy cows with high digestibility, and using it to replace 25% or 50% of imported alfalfa from the Unites States in dairy cows' diet does not affect the rumen fermentation characteristics and rumen apparent digestibility of nutrients of dairy cows. And using whole sugarcane replacing 30% alfalfa hay, 50% oat hay or 10% concentrate will not affect the blood biochemical indicators and production performance of dairy cows, and will also increase the economic benefits of the dairy farm.     

Microbial growth and modification of corn distillers dried grains with solubles during fermentation

Corn distillers dried grains with solubles (DDGS) were fermented with bacteria or yeast. The microbial growth on three DDGS media-unmodified DDGS, enzyme-pretreated DDGS, and supplemented DDGS - was compared with standard media. Comparative growth profile indicated peaks in microbial growths at different times. The highest specific growth rates (SGR) of 0.6, 0.54 and 0.51 h⁻¹ were observed for Saccharomyces Boulardii on unmodified DDGS, yeast extract, and enzyme-modified DDGS, respectively. Pediococcus Acidilactici and Lactobacillus Plantarum had the SGR of 0.17 and 0.07 h⁻¹, respectively, on control DDGS. However, L. Plantarum on unmodified DDGS demonstrated the highest cell count (2.91 × 10¹¹ CFU/mL), followed by S. boulardii at 1.5 × 10⁹ CFU/mL on YEPD, and P. acidilactici at 1.16 × 10¹⁰ CFU/mL on MRS (de Man, Rogosa and Sharpe) media. Protein digestibility of DDGS improved slightly due to fermentation, and resulted in reduced phytic acid content for some treatments. Production of lactic acid was highest on unmodified DDGS.     

不同蛋白质水平对中卫山羊妊娠母羊日粮消化性能的影响

选择体重、年龄相近健康的妊娠母羊30只,随机分为3组。每组10只。采用相同能量水平、不同蛋白质水平的日粮饲养。试验结果表明,在本试验条件下,日粮蛋白质含量以116.57g/d比较有利于中卫山羊妊娠母羊的生长发育。     

Feed intake,digestibility, nitrogen utilization,ruminal condition and blood metabolites in wethers fed ground bamboo pellets cultured with white‐rot fungus (Ceriporiopsis subvermispora) and mixed with soybean curd residue and soy sauce cake

Three types of bamboo pellets as a ruminant feed: P1 (ground bamboo (GB) cultured with the fungus Ceriporiopsis subvermispora (CGB) : soybean curd residue (T) : soy sauce cake (S) in a 5:4:1 ratio on a dry matter (DM) basis); P2 (GB : T : S = 5:4:1 on a DM basis); and P3 (CGB : T : S = 5.5:0.8:3.7 on a DM basis) were prepared. Four wethers were assigned in a 4 × 4 Latin square design experiment to evaluate the applicability of the bamboo pellets. The experimental treatments were C (control): fed alfalfa hay cubes (AC) only, and T1, T2 and T3: fed P1, P2, and P3 with AC by 1:1 on a DM basis, respectively. The digestibility of the DM, organic matter and acid detergent fiber of P1 were significantly higher than those of P2 and P3 (P < 0.05). The total digestible nutrient (TDN) contents of AC, P1, P2 and P3 were 56.5%, 60.2%, 53.2% and 47.0%, respectively. No significant differences in nitrogen retention or ruminal pH and NH₃ were observed among the treatment groups. The results indicate that bamboo pellets cultured with C. subvermispora and mainly mixed with soybean curd residue improved nutritional quality of ground bamboo because of its high digestibility and TDN content.     

氨基酸副产物对青贮饲料发酵品质及消化率的影响

试验旨在研究氨基酸副产物（amino acid by-products,ABP）对全株红高粱和全株甜玉米发酵品质及消化率的影响,并通过扫描电镜（SEM）探讨ABP对青贮饲料发酵品质及消化率的作用机制。试验设无添加剂的对照组和添加2.0% ABP的试验组Ⅰ、2.0% ABP与饲用菌混合添加的试验组Ⅱ,分别进行红高粱和甜玉米的发酵试验,检测其发酵品质及消化率。结果表明：①试验组Ⅰ红高粱和甜玉米青贮pH降至3.90和3.28,感官评定均属于优质青贮饲料。②对于红高粱青贮,与对照组相比,试验组干物质（DM）含量略有提高,但差异不显著（P>0.05）,粗蛋白质（CP）含量显著高于对照组（P<0.05）,试验组Ⅱ纤维成分略低于对照组,但差异不显著（P>0.05）;各试验组乳酸和乙酸含量显著高于对照组（P<0.05）,试验组Ⅱ丁酸含量显著低于其余组（P<0.05）;试验组干物质和中性洗涤纤维（NDF）消化率均高于对照组,但差异不显著（P>0.05）,酸性洗涤纤维（ADF）消化率显著高于对照组（P<0.05）。③对于甜玉米青贮,各试验组干物质和纤维含量均低于对照组,但差异不显著（P>0.05）,粗蛋白质含量显著高于对照组（P<0.05）;试验组Ⅰ乳酸含量显著高于其余组（P<0.05）,试验组Ⅱ乙酸含量显著高于其余组（P<0.05）,而各试验组丁酸含量显著高于对照组（P<0.05）;试验组各养分消化率均低于对照组但高于未发酵原料,其中干物质和酸性洗涤纤维消化率差异显著（P<0.05）。④SEM结果表明,青贮过程中ABP通过破坏红高粱表面蜡质层促进饲用菌的黏附,并降解其细胞壁纤维成分而改善了青贮发酵品质并提高消化率;但ABP对青贮甜玉米蜡质层及细胞壁纤维结构破坏作用不明显。综上,添加ABP可提高红高粱青贮的发酵品质和养分消化率,但对甜玉米青贮的作用不大。     

青霉素菌体蛋白营养价值评定及应用效果研究

分析结果表明：青霉素菌体蛋白含粗蛋白质４１．０％,钙１．４４％,总磷１．１１％,代谢能水平为９．９６ＫＪ／ｇ,５种主要的氨基酸含量如下：赖氨酸１．８４％,蛋氨酸０．６０％,胱氨酸０．６２％,苏氨酸１．７８％,色氨酸０．５０％;表观消化率分别为：８８．４％,９０．７％,６１．９％,８０．４％,９１．４％。通过饲养实验说明,在蛋鸡全价料中添加３％、５％、７％的青霉素菌体蛋白,可获得不低于玉米－豆粕日粮的生产成绩     

Effect of diet composition and slaughter weight on animal performance, carcass and meat quality, and fatty acid composition in veal calves

The effect of true milk use in the diet of Spanish Brown Swiss male calves on animal performance, carcass and meat quality, and fatty acids composition was studied. In experiment 1, the effect of milk intake [ad libitum continuous (ADLIB) feed vs. restricted 0.7 during 75 days followed by ad libitum feed (RESTR)] and slaughter endpoint (225 kg vs. 5 month) were studied. In experiment 2, ad libitum concentrate feeding [grain-fed (GF)] was compared with milk supplementation until slaughter [milk-fed (MF)] in calves slaughtered at 345 kg. As regards to milk intake, carcass weight and degree of fatness were higher in the ADLIB group (P<0.05). The RESTR group revealed a higher percentage of saturated fatty acids (P<0.05). In experiment 2, the MF group exhibited a higher fat percentage (P<0.05), lower press and cooking losses (P<0.05), and higher scores for tenderness and juiciness (P<0.05) than the GF group. The percentage of saturated fatty acids was higher in the MF group (P<0.05). The results suggest that true milk use in veal production could be an advantageous alternative in terms on production costs, animal performance, and carcass and meat quality.     

RPAA和保护性小肽对奶牛生产性能与消化率的影响

选取产奶量、泌乳期及年龄、体重相近的16头处于泌乳中期的荷斯坦奶牛,分为对照组、试验Ⅰ组、试验Ⅱ组和试验Ⅲ组,每组4头牛。试验Ⅰ、Ⅱ、Ⅲ组日粮中分别添加脂肪包被的蛋氨酸和赖氨酸、脂肪包被的小肽、用甲醛处理的蛋氨酸和赖氨酸。结果表明:在奶牛日粮中添加脂肪包被的氨基酸和脂肪包被的小肽,其产奶量分别比对照组提高16.67%、24.02%(P<0.05);乳中固形物和乳脂率没有显著差异,乳蛋白略有升高(P>0.05);饲料干物质、粗蛋白和粗纤维消化率明显提高(P<0.05)。说明脂肪包被的氨基酸、小肽的效果优于甲醛处理的氨基酸组。