日粮精料水平对牦牛和黑白花牛营养物利用率的影响

25月龄的牦牛和15月龄的黑白花牛各3头，于消化代谢笼内进行三期的消化代谢试验，以测定日粮精料水平对牦牛和黑白花牛营养物利用率的影响及两种牛对营养物消化代谢之差异。三期试验所用日粮的精粗比分别为20∶80，50∶50，和80∶20。所有动物自由采食，自由饮水。用全收集法收集粪尿，常规法分析饲料和粪尿样品中粗蛋白（CP），钙（Ca)和磷（P）。结果表明，两种牛在营养物消化率及能量代谢方面无差异，在低精料日粮条件下，牦牛对日粮中的CP，Ca和P的利用率高于黑白花牛。黑白花牛的CP，Ca和P贮留随精料水平上升而迅速上升，而牦牛的CP和Ca贮留几乎不受精料水平的影响。在干物质（DM）消化率方面两种牛间无差异，它们的DM消化率均随日粮料水平升高而升高。黑白花牛的DM采食量随精料水平升高而升高，牦牛对精料粗料比为50∶50的日粮有最高的采食量。这些结果表明，牦牛和黑白花牛的消化吸收功能无差异，牦牛对高粗料型日粮中的营养物的利用率高于黑白花牛。     

牦牛的黑白花牛瘤胃内饲料蛋白质降解率的比较研究

用瘤胃尼龙袋技术研究了青藏高原８种常见饲料在牦牛和黑白花牛瘤胃内的粗蛋白（ＣＰ）和干物质（ＤＭ）降解率,分析了２个动物品种间的降解率的差异性。装有永久性瘤胃瘘管的牦牛（平均体重１００ｋｇ）和黑白花牛（平均体重１７０ｋｇ）各２头,以１．５×ＭＥｍ水平饲喂同一基础日粮（精粗比为５０：５０）,瘤胃食糜的外流速度估计为０．０６７／ｈ（精料）和０．０２／ｈ（粗料）。待测料在瘤胃内的培养时间为２ｈ、４ｈ、６ｈ     

补饲综合营养添加剂对奶牛产奶效果的比较

采用分期试验法对15头黑白花泌乳奶牛进行3期45天饲养试验，结果表明，试验期在奶牛日粮精料中补充添加由赖氨酸，蛋氨酸，微量无比且成的1％的综合营养添加剂，可使产奶量提高9．55％，差异显著（P＜0．05），乳脂主，乳蛋白提高31．6％，差异极显著（P＜0．01），每千克标准奶少耗精料12．5％，每千克标准奶精料成本降低7．3％。     

昭通市养牛业现状及营养背景调查分析

本文通过对昭通市4个乡的肉牛饲料及饲养管理的调查，并对饲料进行常规养分的分析，与肉牛的营养需要NRC（1996）进行对比，发现昭通市农村养牛在传统饲养方式上，粗料型日粮提供的粗蛋白（CP）仅满足了需要量的70％，而精料型基本满足。粗料型和精料型日粮提供的钙（Ca）严重缺乏，平均为41％。粗料型和精料型日粮提供的磷（P）基本满足，平均为116％，Ca、P比例不协调。     

生鲜乳生产技术规程（试行）

（续上期）4饲养管理4．4成母牛各阶段的饲养管理4.4．1干奶期进入妊娠后期，一般在产犊前60d停止挤奶，这段时间称为干奶期。（1）饲养。干奶期奶牛的饲养根据具体体况而定，对于营养状况较差的高产母牛应提高营养水平，从而达到中上等膘情。日粮应以粗料为主，日粮干物质进食占体重的2．0％-2．5％，每千克干物质应含奶牛能量单位（NND）1．75，粗蛋白水平12％～13％，精、粗料比30：70，精料每头每天2．5～3．0kg。     

肉牛高能量日粮快速育肥法

所谓高能量日粮，是指每千克日粮中含代谢能10．9MJ以上，或日粮中精料占70％以上。全粗料日粮型的架子牛在短期内向精料型日粮过渡。120～150d即可育成商品牛出栏。此法肉牛快速育肥，关键要注意以下几点。     

糙米与玉米型饲粮对肉猪饲用价值比较研究

研究了以糙米与玉米分别为主要能量饲料时,2种饲粮对生长育肥猪生产性能、消化代谢、胴体性状及肉品质的影响。结果表明,糙米与玉米型饲粮组生长育肥全期（29kg～90kg）平均日增重分别为715g、703g（P＞0．05）;料重比分别为3．17：1,3．19：1;糙米型饲粮的干物质、有机物质、无氮浸出物、总能的消化率比玉米型饲粮高,其差异达显著水平（P＜0．05）,粗蛋白质、粗脂肪消化率极显著高于玉米型饲粮组（P＜0．01）。糙米型饲粮氮沉积率较玉米型饲粮高22．7％、（P＜0．05）,能量代谢率显著高于玉米饲粮组（P＜0．05）。糙米型饲粮喂猪达上市体重时,其胴体性状及肉品质指标与玉米型饲粮差异不显著（P＞0．05）。     

微生物饲料添加剂在奶牛生产中的应用效果试验

选择10头年龄、体重、胎次、泌乳量相近、健康无病的黑白花奶牛（荷斯坦牛）,两两配对后随机分为2组,2组饲喂精料补充料及粗料相同,试验组在精料补充料中加入0.2%的微生物饲料添加剂。试验结果表明,奶牛日粮中加入微生物饲料添加剂能显著提高奶牛的产奶量（P〈0.05）。     

盘江黄牛育肥效果分析

选择健康无病、体格相近，不同年龄的盘江黄牛24头平均分为4组，其中2岁牛2个组(A、B组)，成年牛2个组(C、D组)，随机将4组牛分为高精料喂量组和低精料喂量组，以研究不同年龄盘江黄牛在育肥过程中给以不同精料日喂量时，其增重能力及育肥效益试验结果，在同喂高精料日粮状况下，2岁牛平均日增重显著低于成年牛日增重(P＜0．05)；在日粮精料量不同时，高精料喂量组牛的增重速度显著高于低精料喂量组(P＜0．05)。表明，牛的采食能力和饲料营养水平是影响肉牛增重的重要因素，日粮的精料喂量也在一定程度上决定肉牛的增重速度。     

日粮中色氨酸和烟酸水平对3周龄肉用仔鸡色氨酸表观可利用率的影响

本试验测定了日粮中色氨酸和烟酸水平对3周龄肉用仔鸡色氨酸表现可利用率的影响。试验结果表明：日粮中色氨酸水平对其表观可利用率有显著的影响（P＜0．01）。肉用仔鸡以晶体L－色氨酸的利用率为102．0％。日粮中烟酸水平对色氨酸的表观可利用率影响不显著（P＞0．05）。日粮中色氨酸或烟酸水平对饲料干物质或氮的表观可利用率影响不显著（P＞0．05）。但日粮中添加0．06％色氨酸可以显著降低3周龄肉用仔鸡粪尿排泄物中氮的含量（P＜0．05），比不添加组和添加0．12％组分别降低了3．27％和3．06％。     

Influence of varying levels of dietary cation anion difference on ruminal characteristics,nitrogen metabolism and in situ digestion kinetics in buffalo bulls

This study was conducted to examine the influence of varying dietary cation anion difference (DCAD) on nutrient intake, digestibility, ruminal characteristics, blood acid base status and in situ digestion kinetics in Nili Ravi buffalo bulls. Four iso‐nitrogenous and iso‐caloric diets having ?110, +110, +220 and +330 mEq/kg dry matter (DM) DCAD were formulated which were represented by A (anionic), LC (low cationic), MC (medium cationic) and HC (high cationic), respectively. These diets were used in four ruminally cannulated Nili Ravi buffalo bulls in a 4 × 4 Latin Square Design. Improved nutrient intake was recorded at high DCAD levels while digestibility remained unaffected. Ruminal ammonia nitrogen, rumen pH, acetate and acetate : propionate ratio were higher in buffalo bulls fed MC and HC diets than those fed A and LC diets. Blood pH and HCO₃^‐ also tended to increase as DCAD level was increased in the diet. Serum Ca and Cl concentrations were higher in bulls fed A and LC diets whereas serum Mg, P and S remained unaffected. Urine pH increased with increasing DCAD level. Nitrogen intake and blood urea nitrogen concentrations were also higher in bulls fed MC and HC diets. There was a consistent increase in ruminal DM and neutral detergent fiber degradability, rate of disappearance and extent of digestion at high DCAD levels in the diet. However, lag time decreased at high DCAD level. This study indicated that buffalo bulls fed MC and HC diets improved feed intake, ruminal characteristics and digestion kinetics.     

粗饲料组合对奶牛饲粮养分消化率、能量和氮的利用的影响

本试验旨在研究粗饲料组合对奶牛饲粮养分消化率、能量和氮的利用的影响。试验采用单因素随机区组设计,将 １６头体重、年龄、胎次相近的,处于干奶期的健康荷斯坦奶牛分为 ４组,每组 ４头。以常用的粗饲料设计 Ａ（玉米青贮 ＋玉米秸秆）、Ｂ（玉米青贮 ＋羊草）、Ｃ（玉米青贮 ＋玉米秸秆 ＋羊草）、Ｄ（玉米青贮 ＋苜蓿草 ＋羊草）４种粗饲料组合的饲粮。结果表明：饲粮Ｄ干物质、有机物和中性洗涤纤维的消化率最高,显著高于其他各饲粮（Ｐ＜０．０５）,其次为饲粮Ｂ和饲粮 Ｃ,饲粮 Ａ最低,显著低于其他各饲粮（Ｐ＜０．０５）,各饲粮的酸性洗涤纤维消化率差异不显著（Ｐ＞０．０５）。粗饲料组合显著影响饲粮摄入总能、能量消化率和能量代谢率（Ｐ＜０．０５）,饲粮 Ｄ甲烷能占摄入总能比显著低于其他 ３种饲粮（Ｐ＜０．０５）。各饲粮的粪氮、尿氮占摄入总氮比差异不显著（Ｐ＞０．０５）,饲粮 Ｄ的氮消化率显著高于饲粮 Ｂ与饲粮 Ｃ（Ｐ＜０．０５）,且饲粮 Ｂ显著高于饲粮 Ａ（Ｐ＜０．０５）;饲粮 Ｂ、饲粮 Ｄ的氮利用率显著高于饲粮 Ａ（Ｐ＜０．０５）。由此可见,玉米青贮 ＋苜蓿草 ＋羊草型饲粮的养分消化率、能量和氮的利用均优于其他各饲粮,羊草与玉米秸秆之间存在正组合效应,两者搭配使用可提高玉米秸秆的消化率,优化能量和氮的利用。     

Replacement effects of Panicum maximum with Ficus polita on performance of West African dwarf goats

The replacement value of Ficus polita for Panicum maximum was evaluated on 32 female post‐weaned West African dwarfs goats. Ficus polita was fed with P. maximum at different proportions of 0:90 (F. polita:P. maximum), 30:60, 60:30 and 90:0 constituting diets 1, 2, 3 and 4 respectively. Each diet was supplemented with 10% cassava peels. Dry matter intake per kg metabolic weight of goats was not significantly (p > 0.05) influenced by the dietary treatments. However, crude protein intake per kg metabolic weight was higher (p < 0.05) in animals fed 60% and 90%F. polita than those fed sole P. maximum diet. Daily weight gain of goats fed diet 3 (60%F. polita) was higher (p < 0.05) (27.3 g) than those fed diets 4 (18.9 g), 2 (20.8 g) and the control (6.6 g). Dry matter (DM), organic matter, crude protein (CP) and neutral detergent fibre digestibilities were higher (p < 0.05) in goats fed 60%F. polita than those fed other diets, except for DM digestibility which was statistically similar to diets 2 and 4 but higher than those fed diet 1 without F. polita. Organic matter and CP digestibility were highest (72.0 and 65.7% respectively) in animals fed 60%F. polita. Nitrogen retention of goats fed 60%F. polita (diet 3) was higher (p < 0.05) than that obtained with other diets. The results suggest that feeding combination of F. polita and P. maximum at ratio 60:30 respectively has associative effects that can enhance growth rate, feed intake, nutrients digestibility and nitrogen utilization for goat production during dry season in the tropics.     

Ruminal dynamics of ad libitum feeding in buffalo bulls receiving different level of rumen degradable protein

Four ruminally cannulated Nili-Ravi buffalo bulls were used in a 4 × 4 Latin Square Design to determine the influence of varying level of ruminally degradable protein (RDP) on dry matter intake (DMI), ruminal characteristics, digestibility, blood pH, blood urea nitrogen (BUN) and nitrogen (N) balance. Four isonitrogenous and isocaloric diets were formulated. The C diet contained 50% RDP while medium, high and very high RDP diets had 66, 82 and 100% RDP of the total crude protein (CP) and were denoted as MRDP, HRDP and VHRDP, respectively. The bulls were fed ad libitum. Nutrients intake decreased linearly with increasing the RDP proportion of total dietary CP. A quadratic effect of RDP on ruminal pH was noticed with increasing level of RDP with quadratic maxima at 66% RDP diet. Increasing level of dietary RDP also had a quadratic effect on total bacterial and protozoal count with maximum microbial count at 82% RDP diet. Increasing dietary RDP resulted in linear increase in DM digestibility. However, neutral detergent fiber digestibility was decreased linearly with increasing the level of dietary RDP. A linear increase in ruminal NH₃–N and BUN was noticed due to increasing level of dietary RDP. Higher positive N balance was noticed in bulls fed C diet compared to those fed MRDP, HRDP and VHRDP diets. The findings of this study indicated that buffalo bulls can effectively utilize 13.12% RDP of DM without any adverse effect on rumen and blood parameters.     

Effect of virginiamycin on in vivo digestibility, rumen fermentation and nitrogen balance

Three experiments were conducted to investigate the effect of virginiamycin. Digestibility was determined with wethers, fed a diet of 0.65 maize silage and 0.35 concentrate on a dry matter basis (Experiment I) or a complete dry feed (Experiment II) at maintenance, and with growing bulls fed a maize silage diet ad libitum supplemented with 7.5 g concentrate per kg live weight (Experiment III). Virginiamycin was incorporated at 0 or 65 ppm in the concentrate and 0 or 25 ppm in the complete dry feed. No significant effect on dry or organic matter digestibility was observed, although digestibilities of protein and ether extract were reduced by virginiamycin in experiments I and II, respectively. Rumen fermentation was studied in experiments I and II. Virginiamycin increased acetic acid concentration and reduced butyric acid concentration in experiment I, but exerted no significant effect in experiment II. An interaction between diet type and virginiamycin was found for the C2/C3 ratio. Nitrogen balance, measured in experiment III, was not affected by virginiamycin.     

不同精粗比柠条青贮日粮对羔羊生产性能和消化代谢的影响

为探讨柠条(Caragana Korshinskii)青贮日粮对羔羊生产性能和消化代谢的影响,以平茬8～10年柠条锦鸡儿(Caragana Korshinskii Kom.)为原料进行青贮。选用小尾寒羊公羔羊30只,采用随机区组设计,试验组饲喂不同精粗比的柠条青贮和精料补充料,对照组饲喂玉米(Zea mays)青贮和精料补充料。结果表明:柠条青贮饲料对羔羊适口性及健康状况无不良影响,干物质采食量随粗料比例增加呈增加趋势,精粗比60:40时羔羊干物质采食量与消化吸率达最大值分别为1131.11 g·d^-1,73.45%,在此精粗比条件下氮沉积量与可消化氮利用率分别为18.33 g·d^-1,62.97%。综合考虑营养物质消化率与养殖效益,以精粗比为60:40为宜,在该精粗比条件下每只羊日收益为1.52元,经济效益较对照提高19.33%。     

Neutral detergent fiber concentration in corn silage influences dry matter intake, diet digestibility, and performance of Angus and Holstein steers

Twelve Angus (237 +/- 13 kg) and twelve Holstein (235 +/- 15 kg) steers were used to determine whether corn silage-based diets with different NDF levels influence DMI to a similar extent in Angus and Holstein steers and as body weight of the steers increase. Steers were randomly assigned to individual slatted-floor pens and used in a crossover design consisting of six 14-d periods. Experimental diets contained corn silage from a normal hybrid (low-fiber; LF) and its male-sterile counterpart (high-fiber; HF) and were alternated each period. The LF and HF diets contained 33.8 and 50.8% NDF, respectively. The HF diet decreased (P < 0.01) overall steer mean DMI 14.0% relative to LF, with mean differences increasing as steers increased in BW (P < 0.01). Feeding the HF diet also reduced ADG by an average of 13.8% relative to the LF diet (P < 0.01). Holstein steers consumed 14.4% more DM and gained 14.3% faster (P < 0.01) than Angus steers. There was a fiber level x breed-type interaction (P = 0.08) for efficiency of gain. Angus steers receiving the HF diet had greater efficiency of gain than Angus steers consuming the LF diet; however, Holstein steers consuming the LF diet had greater efficiency of gain than those receiving the HF diet. The HF treatment reduced total-tract digestibility of DM and GE by 4.6 and 4.5%, respectively (P < 0.01), and decreased DE intake by 20.5% (P < 0.01) but increased apparent totaltract digestibility of NDF and ADF (9.4 and 8.4%, respectively; P < 0.01). Holstein steers had similar digestibility of DM and GE (P > 0.10) but had greater DE intake (P < 0.01) compared to Angus steers. There were fiber level x breed-type interactions for total-tract digestibility of NDF and ADF (P < 0.06). The difference in DM digestibility was negatively associated with the difference in DMI (r2 = 0.23; P < 0.01) for LF minus HF within Angus steers, but not within Holstein steers (P = 0.42). Total-tract digestibility of NDF and ADF was 4.1 and 3.4% lower for the HF diet but was only 1.1 and 0.6% lower for the LF diet when fed to Holstein compared to Angus steers. Results from this trial demonstrate that high-NDF corn silage-based diets reduced intake of both Angus and Holstein steers, and this reduction in DMI continued as steers increased in BW from 235 to 330 kg. Breed differences were also noted for digestible energy intake as influenced by fiber level.     

Nutrients intake,digestibility, nitrogen balance and growth performance of sheep fed different silages with or without concentrate

The experiment was conducted to investigate the influence of maize (Zea mays), sorghum (Sorghum bicolor) and millet (Pennisetum americannum) silages with or without concentrate on nutrients intake, digestibility, nitrogen balance and weight gain in Sipli sheep. Six experimental diets were formulated having 100% maize silage (MS), maize silage and concentrate as 50:50 (MSC), 100% sorghum silage (SS), sorghum silage and concentrate as 50:50 (SSC), 100% millet silage (MiS) and millet silage and concentrate as 50:50 (MiSC), respectively. For this purpose, 24 Sipli lambs were randomly allotted to six experimental diets in a completely randomized design for 90 days, four lambs per diet. The results indicated that among various silage diets, lambs fed MS diet consumed higher dry matter (DM) than those fed SS and MiS diets. Likewise, lambs offered MSC had higher dry matter intake than those fed SSC and MiSC diets. Crude protein (CP) and neutral detergent fibre (NDF) consumed by the lambs also followed the similar trend. Higher DM, CP and NDF digestibilities were also observed in lambs fed MS and MSC diets than those fed SS, SSC, MiS and MiSC diets. Overall digestibilities of DM, CP and NDF were higher in experimental diets containing silage with concentrate. Lambs fed MS diet had 2.79 g/day and 4.45 g/day higher N retention than those fed SS and MiS, respectively. Similarly, lambs fed MSC diet had 2.24 g/day and 5.12 g/day higher N retention than those fed SSC and MiSC diets, respectively. The results showed that lambs fed MSC gained more daily weight gain had better feed conversion ratio than those fed MS, SS, SSC, MiS and MiSC diets. The findings of the present study indicated that lambs fed MSC diet had higher nutrients intake, digestibility, nitrogen balance and weight gain.     

甜高粱青贮与玉米秸秆青贮喂奶牛对比试验

40头中国荷斯坦牛被分为2组,试验组饲喂甜高粱青贮料 配合精料,对照组饲喂玉米秸秆青贮料 配合精料,经80d饲喂,结果表明试验组头日均比对照组多产奶5.25kg,产奶量提高12.16%,头日均节省精饲料2kg,差异极显著(P<0.01),试验组头日均增收4.54元,经济效益明显。     

热应激条件下粗饲料组合对奶牛氮素利用的影响

为了研究粗饲料组合对热应激奶牛氮素利用的影响,试验选取20头胎次和泌乳天数相似的健康荷斯坦奶牛,随机分成2组,每组10头,分别饲喂2种粗饲料组合饲粮:玉米青贮+苜蓿(0.92∶1.00,AF组)和玉米秸秆(CS组)。2组饲粮精料相同,精粗比均为63.7∶36.3。预试期1周,正试期8周。结果表明:1)与CS组相比,AF组奶牛产奶量及能量校正乳、4%脂肪校正乳、乳蛋白和乳糖产量显著或极显著升高(P0.01或P0.05)。2)奶牛对AF组饲粮粗蛋白质表观消化率极显著高于CS组(P0.01)。3)与CS组相比,AF组瘤胃微生物蛋白产量显著升高(P0.05),而尿液和血液尿素氮浓度极显著降低(P0.01)。4)与CS组相比,AF组氮摄入量和乳中氮产量极显著升高(P0.01),但氮转化效率显著降低(P0.05)。结果提示,与玉米秸秆相比,玉米青贮+苜蓿的组合能提高饲粮粗蛋白质水平,增加热应激奶牛粗蛋白质表观消化率,促进瘤胃微生物蛋白和乳蛋白的合成,但氮的转化效率有待提高。