日粮中精料和牧草比例对舍饲山羊增重的影响

报道了在四川省洪雅县进行的一项山羊舍饲试验。试验分3个阶段、4个分组,每组8只5月龄的波尔×成都麻羊杂交公羔(去势),按不同精料与牧草配比饲喂。在舍饲条件下,无论以哪种牧草为基础日粮,随着补饲精料比例的增加,总的干物质采食量相应增加,而牧草采食量有所下降。以牛鞭草为基础日粮时,如果不补饲精料,山羊日增重很低,补饲精料可明显提高日增重。在牛鞭草日粮的基础上增加苜蓿干草,最初阶段因试验羊不太适应,导致日增重降低,但是经过约2周的适应之后,山羊日增重显著提高,但苜蓿干草成本较高,用于饲养山羊并不划算。以多花黑麦草为基础日粮时,山羊增重效果最好,依补饲精料比例的不同(12%~43%),山羊日增重130~189g,10月龄时的胴体重为17.56~25.23 kg。以黑麦草为基础日粮结合补饲精料虽可以提高山羊日增重,但增加精料导致成本过高,净收入降低。综合比较,在黑麦草基础上添加10%精料(干物质基础)的配比最好,每只羊每日可通过增重获得0.64元净收入。     

饲粮抗氧化剂对肌肉嫩度的影响及作用机制

嫩度是肌肉品质重要的感官指标之一,决定肌肉的营养品质和食用品质。而在动物集约化生产过程中,必然产生的氧化应激会对肌肉品质产生巨大的不利影响,因此探索一种有效的措施改善氧化应激对肌肉嫩度的影响至关重要。结合国内外关于肉质嫩度的研究现状,本文主要对氧化应激、抗氧化剂对肌肉嫩度的影响及作用机制进行阐述,旨在为高效合理地利用抗氧化剂改善肌肉嫩度提供借鉴。     

An Adjustable Nutrient Margin of Safety Comparison Using Linear and Stochastic Programming in an Excel Spreadsheet

A stochastic-linear program Excel workbook was developed that consisted of 2 worksheets illustrating linear and stochastic program approaches. Both approaches used the Excel Solver add-in. A published linear program problem served as an example for the ingredients, nutrients, and costs and as a benchmark in the development of the linear and stochastic programs. Standard deviations for ME and nutrients were taken or calculated from CV, and from a commercial publication of sources for amino acids. The Excel spreadsheet was set up so that the calculated margin of safety (MOS) value, according to the requested probability, was the same for both the linear and stochastic programs. As an example, the probability for meeting the nutrient value for protein was compared at 50% (MOS = 0) and 69% (MOS = 0.5) by using both linear and stochastic programming. Spreadsheet results illustrated the flexibility, accuracy, and precision of the stochastic program over the linear program in meeting the requested nutrient probability.     

膨化工艺对乳仔猪日粮养分及生长性能的影响

采用相同配方的膨化颗粒料和普通颗粒料进行哺乳仔猪和断乳仔猪日粮常规营养成分、氨基酸含量、细菌数量、脲酶活性、物理性状分析和乳仔猪生长饲养试验。结果表明 :两种制粒工艺的常规营养成分间差异不显著 :氨基酸总量、必需氨基酸和非必需氨基酸含量膨化料的比普通颗粒料高6.67 %～7.59 % ,差异不显著(P>0.05) ;两种饲料的卫生学和感官指标符合GB13278 -91 ,但膨化料的总细菌和大肠杆菌最可能数少于普通料 ,差异不显著(P>0.05) ;乳仔猪两料中的脲酶活性 ,膨化颗粒料比普通料分别降低56.25 %和28.57 % ,但差异不显著(P>0.05) ;膨化料与普通料相比 ,硬度明显增加 ,其中 ,哺乳仔猪料间差异显著(P<0.05) ,断乳仔猪料间差异极显著(P<0.01) ;膨化料与普通料相比 ,淀粉糊化度哺乳仔猪和断乳仔猪料分别提高32.86 %(P<0.05)和45.45 %(P<0.01)。饲养试验 ,膨化料育成率为96.77 % ,70日龄窝重203.76kg ,窝均盈利1040.83元 ,分别比普通料提高3.85 %(P>0.05)、13.01 %(P>0.05)和36.48 %(P<0.05)。     

Pre-cecal phosphorus digestibility for corn,wheat, soybean meal,and corn gluten meal in growing Japanese quails from 28 to 32 d of age

The optimization of dietary phosphorus (P) depends on precise details of the P availability in feed ingredients to avoid excess or deficient P in a mixed diet. This study was carried out to measure the apparent ileal digestibility of P for corn, wheat, soybean meal, and corn gluten meal in growing Japanese quails from 28 to 32 d posthatch. A total of 400 quail chicks were randomly distributed across 5 treatments with 4 replicates and 20 birds in each floor pen. The P-free diet (PFD) was formulated based on cornstarch to measure the basal endogenous P losses (EPL). Digestibility coefficients were determined by ileal digesta sampling using TiO₂ as an indigestible marker. The EPL was estimated at 384 mg/kg DMI. The apparent ileal P digestibility (AIPD) for corn, soybean meal, wheat, and corn gluten meal were determined to be 0.38, 0.53, 0.38, and 0.78, respectively. The corresponding values for true ileal P digestibility (TIPD) were 0.48, 0.61, 0.50, and 0.83, respectively. The t-test analysis showed that the difference of AIPD and TIPD values for corn (P = 0.031) and wheat (P = 0.015) were statistically significant, however, no significant differences were observed for corn gluten meal (P = 0.318) and soybean meal (P = 0.104). In conclusion, the correction of AIPD coefficients for EPL in low-P ingredients such as corn and wheat may be much more important than that in high-P feedstuffs such as corn gluten meal and soybean meal in growing quails.     

对碘量法测定日粮、肠道食糜及排泄物中半胱胺盐酸盐含量的改进研究

试验旨在探讨碘量法测定日粮、食糜及排泄物中半胱胺盐酸盐(cysteamine hydrochloride,CSH)含量的改进方法,为评估包膜CSH在动物胃肠道内释放过程中CSH的定量提供参考。试验分3部分:试验一:检验包膜CSH的上样量对碘标准液消耗量的线性关系,以确定碘量法检验包膜产品的准确度,采用单因素完全随机设计,CSH的上样量设6个水平,分别为28.28、113.12、226.24、339.36、452.48和565.61mg;试验二:考察H2SO4预处理对消除日粮、食糜和排泄物对碘量法测定CSH含量的影响,采用单因素完全随机设计,日粮、十二指肠食糜、空肠食糜、回肠食糜及排泄物样品中CSH(试剂级)的含量均设3个水平,即30、100和300mg/2g,形成15个含有CSH的样品,H2SO4溶液(6mol/L)设3个水平,即0.1、0.5和1mL,每个处理设3个重复;试验三:考察传统碘量法与试验二建立的改进方法在测定日粮、食糜及排泄物中包膜CSH含量的差异,采用两样本试验设计,日粮、十二指肠食糜、空肠食糜、回肠食糜及排泄物中CSH的含量均设28.73、84.84、141.47和200.56mg/2g。结果表明:①CSH的上样量对碘标准液消耗量及CSH测定值均呈显著的线性关系(P<0.01,R2=0.9999)。②在含有CSH的日粮中,H2SO4溶液处理后由碘量法测定的CSH质量对实际质量的回归均符合Y=X(P>0.05)。在含有CSH的十二指肠食糜和回肠食糜中,所有H2SO4溶液处理下CSH质量对实际质量的回归均不符合Y=X(P<0.05),但0.5和1.0mL比0.1mL H2SO4溶液处理使测定值更接近实际值。在含有CSH的空肠食糜及排泄物中,0.5和1.0mL H2SO4溶液处理使测定值对实际值的回归符合Y=X(P>0.05),而0.1mL H2SO4溶液处理下CSH测定值显著低于实际值(P<0.01)。③在含有CSH的日粮、十二指肠食糜、空肠食糜、回肠食糜及排泄物样品中,常规方法测定的CSH对实际质量均偏离Y=X(P<0.05),而1.0mL H2SO4溶液处理后的测值对实际质量均符合Y=X(P>0.05)。由此可见,采用适量H2SO4溶液进行处理后,可以排除日粮、食糜及排泄物对CSH测定的干扰。     

饲喂玉米型日粮的生长绵羊限制性氨基酸研究

本实验采用９ 只安装有瘤胃、十二指肠和回肠瘘管的生长羯羊, 采用随机区组试验设计,研究了饲喂以玉米、玉米蛋白粉和青干草为基础日粮的绵羊消化道不同部位营养物质流通量,以及由十二指肠瘘管按“递减法”灌注不同氨基酸［Ａ：减赖氨酸（Ｌｙｓ） ;Ｂ：减蛋氨酸（ Ｍｅｔ） ;Ｃ１ ：全量;Ｄ：减苏氨酸（Ｔｈｒ） ;Ｅ：减组氨酸（Ｈｉｓ） ;Ｃ２ ：全量;Ｆ：减精氨酸（ Ａｒｇ） ;Ｇ：减色氨酸（Ｔｒｐ） ;Ｃ３ ：全量］ 对绵羊体内氮沉积、血浆尿素氮（ＰＵＮ） 、血浆游离氨基酸（ＦＡＡ） 浓度等指标的影响。结果表明：饲喂玉米型日粮的绵羊瘤胃食糜流通速率（ Ｋｐ） 为５ ．０９ ％ ～６ ．１５ ％ ／ ｈ , 进入十二指肠中微生物蛋白占总氮的比例为１７ ．７９ ％ ～３０ ．４３ ％ 。绵羊十二指肠中Ｍｅｔ 、Ｌｙｓ 、Ｈｉｓ 和Ａｒｇ 流量偏低,而Ｌｅｕ 的流量较高。与对照组（Ｃ１ 、Ｃ２ 、Ｃ３） 相比,减少Ｌｙｓ 、Ｍｅｔ 、Ｔｈｒ 、Ｈｉｓ 、Ａｒｇ 和Ｔｒｐ 组的绵羊体内沉积氮（ｇ／ ｋｇ Ｗ０ ．７５） 分别下降２３ ．５０ ％ 、４６ ．６７ ％ 、２８ ．６６ ％ 、１５ ．００ ％ 、１７ ．３３ ％ 和１５ ．８９ ％ ;日增重分别下降３７ ．０４ ％ 、５３ ．１７ ％     

双内源指示剂法测定兔饲粮消化能值及其预测模型的研究

本试验旨在研究利用双内源指示剂法测定兔饲粮养分消化率及消化能(DE)值,并建立兔饲粮DE值的预测模型。选用体重相近的4月龄獭兔30只,随机分为3组,每组10个重复,每个重复1只兔。每组饲喂1种饲粮,用全收粪法进行消化试验,用聚酯纤维筛网袋法测定了饲粮中的2种内源指示剂,即酸不溶木质素(ADL)和盐酸不溶灰分(AIA)+ADL的回收率。同时选取了山东省不同饲料公司生产的17种兔颗粒配合饲料,在各自兔养殖场进行饲养试验,利用双内源指示剂法测定兔饲粮DE值,建立兔饲粮DE值的预测模型。结果表明:1)全收粪法测得3种饲粮ADL的平均回收率为99.87%,ADL+AIA的平均回收率为96.81%,二者可作为理想的双内源指示剂。2)利用双内源指示剂法可以准确测定兔饲粮的各种养分消化率和DE值。3)兔饲粮DE值可以用饲粮中可消化有机物质(DOM)含量进行准确的预测:DE(M J/kg)=0.0204DOM(g/kg)或DE(M J/kg)=0.939 5+0.018 2DOM(g/kg)。4)利用兔饲粮中养分[粗蛋白质(CP)、粗脂肪(EE)、可溶性碳水化合物(NDSC)、半纤维素(HCEL)和纤维素(CEL)]含量建立兔饲粮DE值的预测模型为DE(MJ/kg)=0.016 6CP(g/kg)+0.0334EE(g/kg)+0.015 3NDSC(g/kg)+0.005 4HCEL(g/kg)+0.003 1CEL(g/kg)。由此可见,利用双内源指示剂法可以较好地预测兔饲粮的DE值。     

Effects of xylanase supplementation on growth performance,nutrient digestibility,blood parameters,fecal microbiota,fecal score and fecal noxious gas emission of weaning pigs fed corn‐soybean meal‐based diet

This study was conducted to evaluate the effects of xylanase supplementation on nutrient digestibility, growth performance, blood parameters, fecal microflora shedding, fecal score and fecal noxious gas emission of weaning pigs fed corn‐soybean meal based diet. A total of 150 weaning pigs with an average initial body weight (BW) of 7.85 ± 0.93 kg were randomly allocated to three treatments based on BW and sex (10 replicate pens with five pigs, two gilts and three barrows) were used in this 42‐day trial. Dietary treatments were: (1) CON, basal diet; (2) X1, basal diet +0.005% xylanase; (2) X2, basal diet +0.01% xylanase. The xylanase supplementation linearly increased (P < 0.05) average daily gain (ADG), and gain : feed ratio (G:F) from days 29 to 42 and the in overall period, dry matter, nitrogen and energy digestibility, and fecal Lactobacilli counts, and linearly decreased (P < 0.05) blood urea nitrogen (BUN) concentration, fecal NH₃ and H₂S emission. Additionally, at weeks 5 and 6, there was a linear decrease in fecal score with xylanase supplementation. In conclusion, dietary supplementation of xylanase improved growth performance, nutrient digestibility, shifted microbiota by increasing fecal Lactobacillus counts, decreased BUN concentration, fecal score, and fecal NH₃ and H₂S emission in weaning pigs.