添加不同比例补充料对三元杂交肉牛生产性能影响的研究

将18头平均体重为129±7.4kg的三元杂交公牛(本地黄牛×西门塔尔×夏洛来)分成(稻草+米糠)组、(稻草+米糠+棉粕)组、(氨化稻草+米糠)组、(氨化稻草+米糠+棉粕)组、玉米青贮料组、(玉米青贮料+米糠)组共6个组用于研究比较干稻草、氨化稻草和玉米青贮料的饲喂价值。结果表明:(氨化稻草+米糠+棉粕)组肉牛的平均日增重最高(1.01kg/d)且每千克增重成本最低(3.53元)。冬季农户用"氨化稻草+米糠(5g/kg体重/d)+棉粕(1.5g/kg体重/d)"这种方法来饲喂肉牛可获得较理想的生产性能和经济效益。     

豆粕和棉粕蛋白质补充料对育肥肉牛增重效果比较试验

本试验利用棉粕和豆粕作为肉牛的主要蛋白质补充饲料来源,对比两种日粮对肉牛的增重效果。结果表明,棉粕配方饲料组牛群的日均增重量达到1.317kg,明显低于豆粕组的1.647kg的水平,但是,由于棉粕价格低于豆粕,肉牛等量增重所消耗的饲料费用在两组肉牛间无明显差异,认为在精料配方中添加水平合理前提下棉粕可代替豆粕并提高肉牛的育肥效益。     

碳水化合物来源和棉粕添加水平对奶牛采食量、瘤胃发酵和微生物蛋白合成的影响

本研究旨在探讨不同碳水化合物来源和棉粕对奶牛采食量、营养物质消化率、瘤胃发酵及微生物蛋白合成的影响。将4头6月龄的奶牛随机分配到4种日粮处理,日粮按照2×2因子设计,其中两个碳水化合物来源(木薯和木薯与米糠按照3:1混合),两个棉粕水平(109和328 g/kg),两组粗蛋白质水平均为490 g/kg。奶牛补充尿素-石灰处理的水稻秸秆,并按每千克体重补充10 g精料。结果发现:棉籽水平和碳水化合物来源和水平对瘤胃pH、氨氮浓度、微生物蛋白合成和采食量均无显著影响(P 0.05)。以木薯+米糠(3:1)作为碳水化合物来源时,与木薯处理组相比,干物质和有机物的消化率更高(P 0.05)。低棉粕水平组较高棉粕水平组显著提高了蛋白质消化率(P 0.05)。当木薯与米糠为3:1时,该组显著降低了丙酸和丁酸含量(P 0.05)。与3:1的木薯和米糠组相比,木薯组瘤胃细菌总数和蛋白水解菌数量均显著降低(P 0.05)。各处理对瘤胃微生物蛋白合成及合成效率均无显著影响(P 0.05)。因此,使用高水平的木薯和棉粕对奶牛瘤胃微生物种群的能氮平衡产生积极影响。     

复合酶对饲喂棕榈仁粕的肥育猪生产性能和养分利用率的影响

本试验主要研究复合酶制剂对饲喂棕榈仁粕的肥育猪生产性能以及养分利用率的影响.将80头三元杂交的平均体重为50kg的肥育猪随机分成4个处理组:对照组(不添加棕榈仁粕)、5％棕榈仁粕添加组、5％棕榈仁粕和0.1％复合酶添加组、5％棕榈仁粕和0.2％复合酶添加组.整个试验持续8周,每个处理5个重复,每个重复4头猪.结果表明,5％棕榈仁粕添加组的终体重、平均日增重(ADG)和增重耗料比(G:F)显著下降,而对照组与其他两个添加了复合酶添加组的ADG、平均日采食量(ADFI)和G:F无显著差异;另外5％棕榈仁粕添加组的干物质利用率、氮利用率和消化能显著下降(P＜0.05),而对照组与其他两个复合酶添加组无显著差异;各处理组间血液指标无显著差异.总体而言,向含5％棕榈仁粕的猪日粮中添加复合酶可以提高肥育猪的生长性能、能量和养分利用率,从而显著提高棕榈仁粕的营养价值.     

发酵棉粕对安格斯肉牛生长性能和血清生化指标的影响

试验旨在研究饲喂发酵棉粕对安格斯肉牛生长性能和血清生化指标的影响。试验选用10月龄健康初始体重[(259.11±22.62)kg]无明显差异的黑安格斯肉牛(公牛)18头,随机分成两组(每组9头),即试验组和对照组。试验组添加6%的发酵棉粕,对照组添加6%的未发酵棉粕。试验期共42 d,预饲期10 d,正饲期32 d。试验结果表明:(1)试验组平均日增重和平均日采食量与对照组相比较有明显的差异(P<0.05),相较于对照组,试验组平均日采食量提高了31.51%(P<0.05),平均日采食量提高了9.1%(P<0.05);对照组与试验组的料重比相比有极显著差异,和对照组相比料重比下降了16.58%(P<0.01)。(2)对照组和试验组血清中总蛋白、尿素氮、钙、磷、铁、免疫球蛋白A等含量均差异不显著(P>0.05)。血清中总蛋白、葡萄糖及免疫球蛋白G含量,试验组相较于对照组有显著差异,分别提高36.64%(P<0.01)、37.5%(P<0.01)和36.99%(P<0.05)。因此,饲喂发酵棉粕可改善安格斯肉牛的生长性能。     

不同水平葡萄籽渣对西门塔尔牛体外产气量、发酵参数、营养物质消化率和生长性能的影响

[目的] 研究用不同水平葡萄籽渣替代肉牛精料补充料中部分玉米和棉粕对西门塔尔牛体外瘤胃发酵产气量、营养物质体外消化率、发酵参数及生长性能的影响。[方法] 试验采用模拟瘤胃体外培养技术,以4%、8%、12%和16%葡萄籽渣替代肉牛精料补充料中部分玉米和棉粕,测定各组日粮体外产气量、发酵参数、营养物质体外消化率及肉牛生长性能。[结果] 随着体外发酵时间的增加,累计产气量呈递增趋势,12%葡萄籽渣组产气量最大,各组之间72 h总产气量差异不显著（P>0.05）;产气后人工瘤胃培养液pH值、NH₃-N浓度和菌体蛋白含量各组无显著（P>0.05）差异,试验组挥发性脂肪酸浓度显著（P<0.05）升高;16%葡萄籽渣组干物质消化率最低,对照组粗蛋白消化率显著（P<0.05）高于试验组,对照组和4%葡萄籽渣组中性洗涤纤维消化率显著（P<0.05）高于其他三组,对照组和12%葡萄籽渣组酸性洗涤纤维消化率显著（P<0.05）高于其他三组;4%和8%葡萄籽渣组肉牛平均日增重较对照组分别高170 g/d和140 g/d。[结论] 葡萄籽渣替代肉牛精料补充料中部分玉米和棉粕可以提高瘤胃挥发性脂肪酸含量,添加4%和8%葡萄籽渣可以提高肉牛日增重,促进瘤胃发酵,有利于提高肉牛生长性能。     

宜宾五粮型白酒糟在肉牛日粮中应用效果研究

试验旨在研究使用不同比例宜宾五粮型白酒糟(简称酒糟)替代精料补充料对肉牛生产性能和养殖效益的影响。采用单因子随机试验设计,选用25头体重(300±24.1)kg西杂牛(西门塔尔×本地黄牛),随机分为5个处理,每个处理5个重复。分别饲喂用酒糟替代0%(对照组)、30%、40%、50%和60%精料补充料的饲粮,试验期60 d。试验结果显示:肉牛日粮中添加酒糟能显著提高肉牛日增重(P0.05),随着酒糟添加比例的提高,日增重呈二次曲线增加,当替代比例为50%时平均日增重最佳,为(826.7±92)g,较0%、30%、40%和60%替代比例组分别提高了72%、42%、33%和16%。经济效益分析表明,用50%酒糟替代精料,与对照组相比,能有效降低增重成本60.9%,提高增重效益521.7%。因此肉牛饲粮中添加酒糟能有效提高肉牛生产性能,降低饲喂成本,增加经济效益,其中以50%的替代比例效果最佳。     

不同水平烟酸对高精料日粮条件下肉牛生产性能的影响

为了研究不同水平烟酸对高精料日粮条件下肉牛增重和饲料转化率的影响,试验将30头始重约400 kg的西杂肉牛随机分为5组,1组为对照组,饲喂添加1.0%碳酸氢钠的精料;2,3,4,5组分别在精料中添加200,400,600,800 mg/kg烟酸,不添加碳酸氢钠,试验期为63 d。结果表明:在高精料日粮条件下,添加烟酸可以提高肉牛生产性能,且烟酸的作用效果主要体现在试验前期(0~28 d);5组效果最好,试验前期5组肉牛平均日增重和料重比分别为1.92 kg和6.29,与对照组相比差异显著(P0.05);2,3,4组增重效果和料重比与对照组差异不显著(P0.05)。     

在复合酶中添加β-甘露聚糖酶对樱桃谷肉鸭生长性能的影响

研究在高含量棕榈粕-椰子粕日粮中添加复合酶的基础上补充β-甘露聚糖酶对樱桃谷肉鸭生长性能的影响。选择1日龄樱桃谷肉鸭1515羽,随机分为5个组,每组设3个重复,每个重复101羽。对照组为玉米-豆粕-棕榈粕-椰子粕型基础日粮,试验Ⅰ～Ⅳ组为在基础日粮中添加150g/t复合酶FE806G,并分别添加7.5×104、1.5×105、3.0×105和6.0×105IU/tβ-甘露聚糖酶。试验分为前期(1～14日龄)和后期(14～46日龄),共46d。结果表明:在高含量榈粕-椰子粕日粮添加复合酶FE806G的基础上补充β-甘露聚糖酶提高了樱桃谷肉鸭14日龄和46日龄体增重(P0.05),除试验Ⅲ、Ⅳ组后期平均日增重外,添加β-甘露聚糖酶的各组樱桃谷肉鸭各阶段平均日增重和前期平均日采食量均高于对照组,而试验各组后期和全期平均日采食量均低于对照组(P0.05),前期、后期和全期料重比也都低于对照组(P0.05);试验各组前期、后期和全期存活率均不同程度地高于对照组。综上所述,高含量棕榈粕-椰子粕日粮在添加复合酶FE806G的基础上分别补充7.5×104、1.5×105、3.0×105和6.0×105IU/tβ-甘露聚糖酶均能提高樱桃谷肉鸭的生长性能,而综合考虑添加成本,7.5×104IU/t为适宜添加水平。     

非常规饲料原料日粮对肉牛生长性能、胴体性状、肉品质及经济效益的影响

文章旨在评估不同非常规饲料原料替代浓缩料对肉牛生长性能、胴体性状及肉品质的影响。试验选择初始体重为（291.69±5.7）kg的肉牛80头,随机分为4组,每组20头,每头牛为1个重复。对照组肉牛在8周试验期每天自由采食水稻秸秆粗饲料并补充基础浓缩料,处理组肉牛自由采食水稻秸秆粗饲料并分别补充用8%米糠、亚麻籽和葵花粕替代基础浓缩料混合物。结果：与米糠组相比,对照组和亚麻籽组肉牛的平均日增重分别显著提高10.74%和12.40%（P＜0.05）,同时米糠组肉牛的料重比较对照组和亚麻籽组分别显著提高11.69%和15.52%（P＜0.05）。亚麻籽组肉牛的背膘厚度较对照组和米糠组分别显著提高7.84%和8.65%（P＜0.05）。对照组肉牛眼肌C14：0脂肪酸含量显著低于处理组（P＜0.05）,而米糠组肉牛眼肌饱和脂肪酸含量较对照组显著提高16.55%（P＜0.05）,单不饱和脂肪酸含量显著降低11.95%（P＜0.05）。亚麻籽和葵花粕组眼肌中蛋氨酸含量较对照组和米糠组分别显著提高168%、179.17%和154%、164.58%（P＜0.05）。结论：在本研究条件下,用8%亚麻籽替代浓缩料饲喂肉牛可以提高肌肉蛋氨酸含量,对肉牛生长表现及肌肉脂肪酸组成无负面影响。 [关键词]非常规原料|肉牛|生长性能|胴体性状|肉品质     

Elephant grass, sugarcane, and rice bran in diets for confined sheep

We aimed to evaluate the effects of diets, based on elephant grass or sugarcane as roughage and corn meal or rice bran as energy concentrate, on performance and body composition in terms of diet intake and digestibility. A total of 30 Santa Ines crossbreds (SIC), castrated male sheep with 19.8?±?2.0?kg initial body weight (BW) were used. Six animals were slaughtered at the onset of the experiment to estimate the initial body composition for the other animals. The remaining 24 animals were distributed in a completely randomized 2?×?2 factorial design, with four treatments (two roughages and two concentrates) and six replicates. The sheep were slaughtered when they reached 30.0?kg BW. Elephant grass diets provided higher intake and digestibility than sugarcane diets for the following contents: dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fibre, minerals, total carbohydrates (TC), and total digestible nutrients (TDN). Among the concentrates, corn meal diets were associated with higher intakes than rice bran diets for the following contents: DM, OM, CP, TC, and TDN. Animals from all of the treatments exhibited low average daily weight gain and low protein and high fat and energy body levels. Sugarcane and rice bran can be used as ingredients in diets for sheep with low weight gain potential. Regardless of roughage or concentrate types used in diets for confined SIC sheep, performance and body composition remained unaltered.     

Intake,growth and carcass yield of indigenous goats fed market wastes of sweet potato (<Emphasis Type="Italic">Ipomoea batatas</Emphasis>) vines and scarlet eggplant (<Emphasis Type="Italic">Solanum aethiopicum</Emphasis>)

Intake, growth and carcass yield of indigenous goats fed basal diets of market wastes of sweet potato (Ipomoea batatas) vines (SPV) and scarlet eggplant (Solanum aethiopicum) (SEP) were examined in two experiments. In experiment I, the effect of presentation method (chopping, hanging or adding molasses) on the intake of SEP and SPV was evaluated. Presentation method did not influence the intake of SPV while hanging resulted in the highest (P < 0.05) intake of SEP. In experiment II, 24 male growing goats were supplemented with a concentrate (25% cottonseed cake +75% maize bran) in four dietary groups: SEPD, SPVD, SEP+SPV and Control where elephant grass (Pennisetum purpureum) was offered as the roughage. SEP were offered by hanging, while SPV were chopped. The goats were slaughtered after 12 weeks of feeding. Goats in the SEPD group constantly lost weight, hence were not followed to the end. Average daily gain and hot carcass weight were highest (P < 0.05) in the SPVD group (44 g/d and 8.4 kg, respectively), but similar between the SEP+SPV (19 and 6.8) and Control (21 and 6.9) groups. In conclusion, SPV can support goat meat production where standard feed resources are scarce when fed with an energy-protein concentrate. SEP are poorly consumed by goats, hence cannot be used as their sole basal feed.     

青鱼对8种饲料原料中营养物质的表观消化率

本试验旨在研究青鱼(Mylopharyngodon piceus)对国产鱼粉、蝇蛆粉、玉米蛋白粉、大豆粕、花生粕、棉籽粕、菜籽粕和米糠8种饲料原料干物质、粗蛋白质、氨基酸、粗脂肪、总磷和总能的表观消化率。试验饲料由70%基础饲料和30%待测饲料原料组成,并以0.1%的三氧化二钇(Y2O3)为外源指示剂。选取平均体重为(60.17±1.28)g的青鱼270尾,随机分成9组,每组3个重复,每个重复10尾鱼。对照组试验鱼饲喂基础饲料,试验组试验鱼分别饲喂1种试验饲料。饲喂1周后采用自排法收集粪便待测。结果表明:8种饲料原料的干物质、粗蛋白质、粗脂肪、总磷、总能以及总氨基酸的表观消化率的范围分别是62.17%～86.47%、83.34%～95.84%、78.93%～100.06%、37.33%～81.99%、66.75%～89.86%、86.33%～96.58%。在8种饲料原料中,玉米蛋白粉的干物质、总磷和总能的表观消化率最高,而大豆粕的粗蛋白质、粗脂肪和总氨基酸的表观消化率最高;棉籽粕的干物质和总能的表观消化率最低,米糠的粗脂肪和总磷的表观消化率最低。各饲料原料中总氨基酸表观消化率与粗蛋白质表观消化率的变化趋势一致,其中以蝇蛆粉最低。由此可见,大豆粕和玉米蛋白粉是青鱼的优质植物蛋白质源,可适量替代鱼粉;蝇蛆粉中粗蛋白质和氨基酸的消化率都较低,在青鱼饲料中的添加量不宜过高;花生粕、棉籽粕和菜籽粕也是较好的植物性蛋白质源,在青鱼饲料中适量添加既有利于饲料的营养平衡,还可降低饲料成本;米糠作为青鱼的能量原料必须保持新鲜,并控制其在饲料中的用量。     

Effects of breed and wintering diet on heifer postweaning growth and development

Fifteen spring-born Angus (AN) and 25 Brangus (BN) weanling heifers were used in a 2x5 factorial arrangement of treatments to evaluate the effects of breed and postweaning winter diet on heifer growth and development. Dietary treatments were warm-season perennial grass hay (H), ammoniated H (AH), H plus .68 kg/d cottonseed meal (HP), H plus .45 kg/d cottonseed meal plus 1.37 kg/d ground corn (HPE) and HPE plus 200 mg/d monensin (HPEM). Mean initial weight and age for the 107-d feed trial were 207 kg and 270 d. Brangus had .06 kg greater (P less than .05) ADG than AN during the trial. Although digestible DM intake (DDMI) relative to body weight was greater (P less than .10) for AN than for BN, ADG:DDMI was greater (P less than .05) for BN than for AN. Heifers fed H and AH lost weight, but heifers fed AH had 50% (P less than .05) less daily weight loss than those fed H. Daily gain increased (P less than .05) incrementally in response to sequential supplement additions of cottonseed meal (AH vs HP; -.10 vs .17 kg), ground corn (HP vs HPE; .17 vs .29 kg) and monensin (HPE vs HPEM; .29 vs .39 kg). Hay DM intake relative to body weight and DDMI were increased (P less than .01) by ammoniation. Intake did not differ between HPE and HPEM. Diet affected age at puberty (P less than .05), which decreased with increased dietary components. Weight differences among diet groups following the winter feed trial were largely eliminated prior to breeding. Nevertheless, H- and AH-fed heifers collectively weighed less (P less than .01) prior to breeding than did heifers of supplemented diet groups. Reproductive development tended to be adversely affected by weight loss during the postweaning period.     

Utilization of alternative protein meals with or without multiple-enzyme supplementation in broilers fed low-energy diets

An experiment was conducted to study the effect of different protein meals, with or without enzyme supplementation, on the performance of broilers. A diet based on a combination of protein meals (15% soybean meal, and 5% each of sunflower meal, canola meal, rapeseed meal, and cottonseed meal) was compared with 4 other diets containing 15% soybean meal and 20% of sunflower meal, canola meal, rapeseed meal, or cottonseed meal. Experimental diets were formulated to contain 2,630 kcal of ME/kg and 0.95% digestible lysine, with all other essential amino acids set to meet or exceed the ideal protein ratios. Each diet was fed with or without supplemental exogenous enzyme (Rovabio Excel at 500 g/metric ton of feed) to 6 replicate pens of 50 chicks from 1 to 35 d posthatch as coarse mash. In the cottonseed meal-based diet, supplemental enzyme resulted in high 35-d feed intake and FCR compared with the cottonseed meal-fed groups with no enzyme. There was a significant (P < 0.05) diet × enzyme interaction for 35-d feed intake and FCR. Birds fed the sunflower meal-based diet had significantly (P < 0.05) higher final BW gain and lower FCR as compared with those fed rapeseed meal- or cottonseed meal-based diets, whereas the BW gain of birds fed the rapeseed meal-based diet was significantly (P < 0.05) reduced compared with birds in all other groups. In conclusion, in low-ME broiler diets formulated on a digestible amino acid basis, up to 20% sunflower meal and canola meal can be safely incorporated into the diet. Supplementation of Rovabio failed to exert any positive effect on production parameters when used with diets containing high levels of each of the common protein meals.     

Effects of supplemental energy and/or degradable intake protein on performance,grazing behavior,intake, digestibility,and fecal and blood indices by beef steers grazed on dormant native tallgrass prairie

To evaluate the effects of balancing total diet degradable intake protein with dietary total digestible nutrients (TDN), we conducted two studies during 2 yr with 100 (302 +/- 8 kg initial BW) mixed-breed yearling steers and 12 ruminally cannulated steers (526 +/- 28 kg). Steers individually received one of four supplements 5 d/wk while grazing dormant native tallgrass prairie. Supplements included: 1) corn and soybean meal, balanced for total diet degradable intake protein in relation to total diet TDN (CRSBM), 2) corn and soybean hulls, equal in supplemental TDN to CRSBM (CORN), 3) soybean meal, equal in supplemental degradable intake protein to CRSBM (SBM), or 4) a cottonseed hull-based control supplement (CONT). At each feeding (5 d/wk), steers consumed 13.6, 13.6, or 4.2 g of dry matter/kg of body weight, or 178 g of DM, respectively, of supplement. Steers fed CRSBM had greater (P < 0.01) average daily gain than cattle fed CORN or SBM. Feeding soybean meal (CRSBM, SBM) resulted in improved (P < 0.01) efficiency of supplement. Grazing time, intensity, and harvesting efficiency were reduced (P < 0.05) by corn supplementation (CRSBM and CORN), whereas the number of grazing bouts per day was increased (P < 0.08). Intake and digestibility of forage organic matter were reduced (P < 0.01) for steers supplemented with corn (CORN and CRSBM) vs cattle not fed corn (SBM and CONT). Total diet digestibility (P < 0.12) and digestible organic matter intake (P < 0.01) were greater for CRSBM-fed steers than for cattle fed either CORN or SBM. Steers fed CRSBM had greater (P < 0.01) fecal nitrogen and serum insulin than cattle fed CORN or SBM. Corn-fed cattle had lesser (P < 0.01) fecal pH and ADF concentrations than steers not consuming grain. Cattle fed supplements with soybean meal (CRSBM and SBM) had greater (P < 0.01) serum urea nitrogen than steers fed supplements without soybean meal (CORN, CONT). Supplemented steers grazing dormant tallgrass prairie had a greater rate of gain, with the greatest response in animal performance occurring when grain supplements were balanced for total diet degradable intake protein in relation to total diet TDN. These results lead us to suggest that grain-supplemented cattle grazing dormant tallgrass prairie require a balance of total diet degradable intake protein in relation to total diet TDN to optimize animal performance.     

Cecotrophy behavior and use of urea as non-protein nitrogen (NPN) source for capybara (Hydrochoerus hydrochaeris)

Fifteen female adult capybaras, with initial average body weight (BW) of 32.7 (±?5.8) kg, were kept in individual pens to evaluate effect of supplementation of concentrate feed and its supply time on cecotrophy behavior frequency. The animals were allocated in a completely randomized design, with five animals per treatment, receiving three diets: grass only, grass and grain corn offered in a single meal, and grass and grain corn offered in two daily meals; all cecotrophy acts were recorded. Later, in a second experiment, five capybaras received five levels of urea in their diet: 0, 10, 20, 30, and 40 g urea/100 kg BW, replacing soybean meal as true protein source, in a 5?×?5 Latin square design. The animals were weighed and their blood was collected every 2 weeks. The frequency of cecotrophy (Ps?<?0.05) was higher when the capybaras were fed grass only (0.5?±?0.07 acts/h) than when they received grass and corn in a single meal (0.3?±?0.05 acts/h) and grass and corn supplied in separate meals (0.1?±?0.03 acts/h). With increased urea in their diet, the capybaras showed initial signs of chronic intoxication, together with increments in serum urea (r?=?0.87, P?<?0.05) and a decreasing trend in daily weight gain (r?=??0.38, P?=?0.06). Therefore, when including concentrate feeds in capybara diet, these must be mixed with roughage in a single meal to avoid high decrease in the frequency of cecotrophy behavior and increase in dry matter intake. The replacement of soybean meal with urea in capybara diet is not recommended.     

鳙鱼对10种蛋白质饲料原料中营养物质的表观消化率

本试验旨在研究鳙鱼(Aristichthys nobilis)对鱼粉(国产)、干酒糟及其可溶物(DDGS)、菜籽粕、米糠、豆粕、酶解羽毛粉、棉籽粕、小麦麸、玉米蛋白粉和花生粕中干物质、粗蛋白质、粗脂肪、总能以及氨基酸的表观消化率。试验饲料按照基础饲料和待测饲料原料7∶3的比例构成,并添加0.5%的三氧化二钇(Y2O3)作为外源指示剂。挑选初体重为(290.02±2.82)g的鳙鱼,随机分成11组,每组3个重复,每个重复10尾鱼。随机选取1组作为对照组投喂基础饲料,剩余10组为试验组分别投喂试验饲料。投喂1周后通过虹吸法收集粪便。结果表明:1)10种饲料原料中干物质、粗蛋白质、粗脂肪和总能的表观消化率的范围分别为69.9%~85.7%、73.5%~88.3%、81.2%~91.1%和81.9%~86.3%。2)在10种饲料原料中,米糠总能的表观消化率最高,而鱼粉的干物质、粗蛋白质和粗脂肪的表观消化率最高;酶解羽毛粉的干物质、粗脂肪和总能的表观消化率最低,玉米蛋白粉的粗蛋白质的表观消化率最低。3)各饲料原料氨基酸的表观消化率基本维持在65.59%~99.17%,且都以小麦麸较低。由此可见,鳙鱼对鱼粉具有很好的利用效果,其次是豆粕和花生粕,而酶解羽毛粉中粗蛋白质的表观消化率最低,小麦麸各氨基酸的表观消化率均比较低。     

Influence of protein type and level on nitrogen and forage use in cows consuming low-quality forage

Minimal quantities of ruminally degradable protein from supplements may improve supplement use efficiency of ruminants grazing dormant forages. In Exp. 1, N retention, ruminal NH(3), serum urea N, and NDF digestibility were evaluated for 12 ruminally cannulated cows (Bos spp.) in an incomplete Latin Square design with 3 periods of 42 d each. Cows were fed weeping lovegrass [Eragrostis curvula (Schrad.) Nees] hay (4.1% CP, 75% NDF, OM basis) at 1.3 % BW/d and offered 1 of 3 sources of CP [urea, cottonseed (Gossypium spp.) meal (CSM); or 50% blood meal and 50% feather meal combination (BFM)] fed to supply 0, 40, 80, or 160 g/d of CP. Beginning on d 22 of supplementation, ruminal contents and serum samples were collected at -2, 0, 3, 6, 9, 12, 18, 24, 30, 36, and 48 h relative to the morning offering of hay. On Day 24, feces and urine were collected for 72 h. In Exp. 2, 4 ruminally cannulated steers were used in a replicated 4 by 4 Latin Square to evaluate use of supplements differing in quantity and ruminal CP degradability. Steers were fed 6.8 kg/d chopped sudangrass [Sorghum bicolor (L.) Moench nothosubsp. drummondii (Steud.) de Wet ex Davidse] hay (3.7% CP, 74% NDF on OM basis) and supplemented with 56 g/d of a salt mineral mix (CON); CON + 28 g/d blood meal + 28 g/d feather meal (BFM); CON + 98 g/d CSM (LCS); or CON + 392 g/d CSM (HCS). Treatments provided 0, 40, 40, or 160 g/d of CP for CON, BFM, LCS, and HCS respectively. In Exp. 1, N use and total tract NDF digestibility were not affected by protein sources or amounts (P ≥ 0.18). Ruminal NH(3) concentrations exhibited a quadratic response over time for UREA (P < 0.05) and was greater with increasing inclusion of urea (P < 0.05); whereas BFM or CSM did not differ (P > 0.05) by amount or across time. In Exp. 2, supplementation had a tendency (P = 0.09) to increase DM disappearance. Supplementation also increased (P < 0.01) serum glucose concentrations; however, no difference (P ≥ 0.28) was found between supplements. Serum urea N and ruminal NH(3) concentrations were increased (P ≤ 0.01) in steers fed HCS. Feeding low quantities of a high-RUP supplement maintained rumen function without negatively affecting DM or NDF digestibility of a low-quality forage diet.     

Neem (Azadirachta indica) kernel meal in the diet of White Leghorn layers

1. Neem kernel meal (NKM) was incorporated into a standard layer diet at 0, 100, 150 and 200 g/kg, replacing parts of the soyabean meal and deoiled rice bran. Each diet was offered to 18 White Leghorn layers (25 weeks, 50% egg production) in individual cages for a period of 12 weeks. 2. Results indicated significantly lower food intakes (P<0.01), rates of egg production and egg weights in birds fed on the diets with NKM at 150 and 200 g/kg. Fertility and hatchability were also adversely affected by the higher inclusion rates of NKM. 3. Except for lower egg shell weight and shell thickness (P<0.05) in hens fed NKM at 150 and 200 g/kg, the internal egg quality characteristics were comparable in all groups. 4. Feeding NKM beyond 100 g/kg to laying hens significantly (P<0.01) reduced the content of haemoglobin, erythrocyte count, packed cell volume, serum calcium and uric acid concentrations. However, the leucocyte count, plasma glucose concentration and serum glutamate oxaloacetate transaminase activity were unaltered. Serum glutamate pyruvate transaminase activity was significantly (P<0.05) reduced in birds fed NKM at 200 g/kg. 5. Thus NKM at 100 g/kg in a layer diet would appear to be safe and cost-effective.