Effect of feeding wood kraft pulp on the growth performance,feed digestibility,blood components,and rumen fermentation in Japanese Black fattening steers

This study aimed to examine the effects of feeding kraft pulp (KP) on the growth performance, feed digestibility, and rumen fermentation of Japanese Black fattening steers. Ten Japanese Black fattening steers (aged 26 months) were randomly divided into control and KP groups. The control group (n = 5) was fed concentrate feed without KP, and the KP group (n = 5) was fed concentrate feed containing 10% KP. Both the groups were provided rice straw as roughage. The experiment was conducted over a period of 12 weeks. There was no significant difference in dry matter intake, daily body weight gain, and nutrient digestibility between both groups. No difference was observed in the ruminal concentrations of volatile fatty acids among the groups. At weeks 8 and 12 after the onset of the experiment, the acetate‐to‐propionate ratio in the ruminal fluid of the KP group was significantly higher than that of the control group. The average daily pH of ruminal fluid and activity of ruminal lipopolysaccharide did not differ between the groups. Our results suggested that the growth performance and feed digestibility in the Japanese Black fattening steers were not influenced by replacing concentrate feed with KP.     

采食后奶牛瘤胃短链脂肪酸及其吸收相关蛋白表达的研究

本试验旨在研究奶牛采食前后瘤胃中短链脂肪酸(SCFA)浓度的变化及其吸收相关蛋白表达量的差异。试验选用3头体重(720±30)kg且装有瘘管的健康荷斯坦牛(动物伦理审查编号为SXAU-EAW-2019-C002013),采食精粗比为40:60的日粮(10kg),试验预试期10d,于第11天饲喂前开始取样,采用气相色谱法检测奶牛采食前(0 h)和采食后(1、2、3、4、5、6、7、8 h)瘤胃液中SCFA浓度;并采用荧光定量PCR方法检测瘤胃上皮组织中与SCFA吸收相关的蛋白表达量。结果表明:在采食后1 h奶牛瘤胃中SCFA浓度最高(P<0.05);在采食后一段时间内(2~5h)与SCFA吸收相关蛋白表达量上调(P<0.05),AE2、MCT1基因表达量均在5 h最高,PAT1、NHE3基因表达量均在4 h最高,MCT4基因表达量在4、5、6h均较高,NHE1基因表达量在2h达到最高;AE2、MCT1、MCT4、NHE1基因表达量与SCFA浓度负相关或正相关(P<0.05),AE2、MCT1、MCT4基因表达量与瘤胃内pH正相关(P<0.05)。以上结果初步揭示,在采食后一定时间内,瘤胃中与SCFA吸收相关蛋白表达受SCFA浓度和pH的调节。     

2019年肉牛饲料与营养评价的国外研究进展

文章旨在了解饲料与营养对肉牛生产性能、消化性能、瘤胃发酵以及甲烷(CH₄)排放的影响。文章综述了2019年国外的相关文献报道,主要从精饲料、粗饲料及饲养营养综合评价3个方面进行综述。精饲料集中于各种蛋白质饲料和能量饲料的研究。粗饲料研究侧重于粗饲料品种和加工方式对不同生理阶段肉牛生产性能、消化性能和CH₄产生的影响。饲料营养综合评价主要侧重于犊牛期研究,并对育肥期和放牧期肉牛的饲料营养进行评价,以根据肉牛的生理阶段特点,选择适宜的饲料原料,并合理搭配和调制日粮以改善瘤胃菌群结构,充分提高养分利用率。     

Comparison of fattening performance in Brahman grade cattle (Bos indicus) and crossbred water buffalo (Bubalus bubalis) fed on high roughage diet

The objective of this study was to compare the fattening performance in Brahman grade cattle (crossbred cattle) and crossbred water buffalo at the same young age and fed with high roughage based fattening rations in the Philippines. Ten crossbred cattle and 10 crossbred water buffalo, aged between 18 and 24 months old were used in this experiment. The animals were fed diets consisting of 85% Napier or Para grass and 15% concentrate mixture (CM) on a dry matter (DM) basis. The grass, total DM intake and bodyweight gain were significantly (P < 0.01) higher for the crossbred water buffalo than for the cattle. There was no species significant difference in the digestion coefficient and feed conversion rate between the crossbred cattle and water buffalo. The return over feed cost for fattening was significantly (P < 0.05) higher in the crossbred water buffalo than in the cattle. These results clearly indicate that under high roughage‐based fattening rations, young crossbred water buffalo are better able to utilize the roughage and they perform better in terms of feed intake and live weight gains than the crossbred cattle in the Philippines.     

The effect of short chain fatty acids on calcium flux rates across isolated rumen epithelium of hay-fed and concentrate-fed sheep

The present in vitro experiment was conducted to study the effect of two concentrations of short chain fatty acids [SCFA: 0 (control), 40 and 100 mmol/l in the buffer solution on mucosal side] on calcium ion (Ca2+) transport across the isolated rumen epithelium of two groups of sheep. One group was subjected to hay ad libitum, whereas the other to concentrate feed (800 g per day in equal portion at 7.00 and 15.00 hours and hay ad lib). The conventional Ussing chamber method was used for measuring the Ca2+ transport rates (45Ca), short-circuit current (Isc) and tissue conductance (GT) of isolated rumen epithelium. The SCFA significantly increased Isc of the epithelia of concentrate-fed sheep. In both hay- and concentrate-fed animals, 45Ca flux rates showed an almost linear increase in net flux rate () with rising concentrations of SCFA, as a result of a combined effect of a large increase in mucosal-to-serosal flux rates () and an almost linear, but small, decrease in serosal-to-mucosal flux rate (). In concentrate-fed sheep and were significantly higher in tissues incubated with SCFA compared with hay-fed animals. The well-known adaptable morphological and functional changes in the rumen epithelium attributable to concentrate feeding obviously include Ca2+ transport; such feeding therefore may be considered as a possible prophylactic measure in the prevention of milk fever.     

育肥牛低精料日粮配合方案饲喂效果分析

根据肉牛不同发育阶段的生理特点和补偿代谢机制,采用分阶段低精料日粮设计方案,育肥前期以粗饲料为主,适当补充蛋白饲料,育肥后期以高能量饲料为主,粗饲料作为调节适量饲喂。通过与持续精料日粮方案对比可知,低精料日粮方案育肥牛平均日增重1．57kg,较持续精料日增重相对提高了15．9％;低精料日粮方案节约精饲料用量、降低育肥成本,饲养成本较持续精料日粮方案降低了22．7％。试验结果表明,分阶段低精料日粮设计方案可减轻持续饲喂精料对育肥牛瘤胃造成的伤害,进而保证了育肥牛的健康生长。     

异地育肥肉牛的饲养管理技术

肉牛“异地育肥”已成为我国肉牛生产的一种主要模式。购入架子牛后,首先应注意减少运输应激的影响,做好过渡期的饲养管理,按体重大小、体质强弱、采食饲料快慢进行分群合栏。对于体重小于200kg的小架子牛来讲,饲养的重点是促进骨骼、内脏、肌肉的生长,使其消化器官得到锻炼,要求日粮提供优质蛋白质饲料,并供给适量的钙、磷、矿物质、维生素;体重为200~250kg的牛源,要求日粮的蛋白质含量高,可以提供充裕的粗饲料以促进其瘤胃发育;250~300kg体重阶段的架子牛,日粮以粗料为主,以精料为辅;体重达350kg的大架子牛其日粮的营养需要是前期蛋白质含量应高一些、后期能量水平要高些。牛的出栏体重越大,饲料利用率就越低,因此应根据肉牛育肥目的,适当育肥,适时出栏。     

Site and extent of starch degradation in the dairy cow - a comparison between in vivo, in situ and in vitro measurements

Prediction of the supply of glycogenic precursors to dairy cows and the site of degradation of wheat, maize and potato starch (PS) were determined in an in vivo experiment and the results were compared with data obtained from experiments involving in situ nylon bag and in vitro gas production techniques. In a Latin square design experiment four lactating dairy cows fitted with a rumen cannula and T-piece cannulae in the duodenum and terminal ileum, received either a low-starch control diet or diets in which sugar beet pulp in the concentrate mixture had been replaced by wheat, maize or PS. Starch from the different sources was almost completely degraded in the total gastrointestinal tract. For all starches, the rumen was the main site of degradation in vivo. No digestion of PS in the small intestine was observed. In situ results suggested that 14% of wheat starch (WS), 47% of maize starch and 34% of PS escaped rumen fermentation. According to the gas production technique WS ferments quickest and potato slowest. PS had a low degradability during the first 8 (gas production) to 11 (in situ) h. However, according to both in vitro and in vivo measurements rumen degradability of PS was high. The results suggest that in situ and in vitro techniques should be performed in animals that have adapted to starch source to provide a more accurate simulation of the in vivo situation.     

不同肉牛育肥的牛肉产品生产对饲料粮消耗比较分析

在对繁殖母牛、哺乳犊牛和架子牛进行饲养试验及调查的基础上,结合所进行的架子牛育肥试验和犊牛直线育肥试验,参考肉牛饲养标准和已发表的肉牛育肥试验数据,并根据目前我国牛肉产品提供状况和肉用牛育肥的饲料资源情况,分别比较不同肉牛育肥牛肉产品生产所需要的粮食。结果表明,为获得等同重量的肉牛产品,直线育肥技术比后期集中育肥要消耗较少的粮食,而高档牛肉生产（高端肉产品生产）需要消耗更多的饲料粮。     

平原农区商品肉牛生产发展模式探讨（上）

平原农区肉牛生成正从传统，分散经营向商品化，规模化，集约化和系列化方向转化，已初步形成场户结合就地服育，异地肥育，生产－加工－销售一体化和商品肉牛繁殖育肥场四种经营模式；氨化（碱化）秸秆＋精料，青贮饲料＋精料，槽渣类饲料＋精料等三种有效饲养模式。本文在分析现有模式的基础上提出四种经营模式的适应区域，推广条件和发展趋势。并根据本人试验研究结果，参考国内外有关资料，提出完善上述三种饲养模式应以研制专用     

膨化秸秆微生物发酵饲料对杜寒杂交肉羊生长性能和胃肠道发育的影响

[目的] 研究膨化秸秆微生物发酵饲料对杜寒杂交肉羊生长性能和胃肠道发育的影响。[方法] 选择81只3月龄、体重为（23.0±1.0）kg的杜寒杂交羔羊,随机分为对照组（70%精料+30%干秸秆）、试验Ⅰ组（70%精料+30%膨化秸秆微生物发酵饲料）和试验Ⅱ组（70%精料+30%膨化秸秆微生物发酵饲料,添加占日粮总蛋白浓度10%的膨化缓释尿素,NPN≥100%）。试验期为75 d,预饲期为15 d,正饲期为60 d。分析育肥羊的增重,胃肠道组织重量和表观形态。[结果] 膨化秸秆微生物发酵饲料极显著（P<0.01）提高试验组羊的采食量和日增重。试验组羊的大肠重,消化道总重和瘤胃容积均显著（P<0.05）高于对照组,试验Ⅱ组羔羊瘤胃内壁颜色优于其他组。[结论] 膨化秸秆微生物发酵饲料促进了育肥羊生长性能和胃肠道发育,试验Ⅱ组的作用更明显。     

Effect of monensin withdrawal on rumen fermentation,methanogenesis and microbial populations in cattle

This study was designed to obtain information on the residual influence of dietary monensin on ruminant fermentation, methanogenesis and bacterial population. Three ruminally cannulated crossbreed heifers (14 months old, 363 ± 11 kg) were fed Italian ryegrass straw and concentrate supplemented with monensin for 21 days before sampling. Rumen fluid samples were collected for analysis of short chain fatty acid (SCFA) profiles, monensin concentration, methanogens and rumen bacterial density. Post‐feeding rumen fluid was also collected to determine in vitro gas production. Monensin was eliminated from the rumen fluid within 3 days. The composition of SCFA varied after elimination of monensin, while total production of SCFA was 1.78 times higher than on the first day. Methane production increased 7 days after monensin administration ceased, whereas hydrogen production decreased. The methanogens and rumen bacterial copy numbers were unaffected by the withdrawal of monensin.     

2015年国外肉牛饲料营养的研究进展

为了全面了解肉牛饲料营养的最新研究进展,作者查阅并总结了2015年关于肉牛饲料营养的国外文献报道,主要从精饲料、粗饲料以及精、粗饲料搭配3个方面进行了综述。精饲料主要包括蛋白质饲料和能量饲料,其中蛋白质饲料的营养研究主要侧重于不同蛋白质饲料对肉牛消化性能、生产性能、酮体特性和肉质以及瘤胃发酵的影响;能量饲料的营养研究侧重于不同类型及加工工艺对肉牛的生产性能、胴体特性以及瘤胃发酵特性的影响;粗饲料的营养研究主要集中于粗料来源及粗料的加工工艺对肉牛生产性能和消化性能两个方面的影响。另外,对精、粗饲料的搭配比例对肉牛生产性能、胴体特性、瘤胃发酵以及采食行为的影响也进行了综述。通过总结和分析肉牛饲料营养的国外研究成果,为中国肉牛业的快速发展提供一定借鉴。     

不同颗粒日粮对滩羊育肥羊生长性能、养分表观消化率及血清生化指标的影响

旨在探究不同颗粒日粮对育肥羊生长性能、养分表观消化率及血清生化指标的影响.选取体重相近、(70±10)日龄的滩羊羯羔羊60只,随机分为4组:对照组(n=15)、试验Ⅰ组(n=15)、试验Ⅱ组(n=15)、试验Ⅲ组(n=15).对照组饲喂自配全混合日粮(40％自配精饲料+60％自配粗饲料),试验Ⅰ组饲喂50％自配全混合日...     

皇竹草与玉米秸秆青贮料饲喂肉牛的对比试验

利用皇竹草和抽穗期玉米秸秆青贮料作为能繁母牛、育肥牛的主要青粗饲料开展对比试验。通过120 d饲喂对比试验,饲喂2种不同饲料的能繁母牛受胎率分别为70.37%和76.92%,说明皇竹草和抽穗期玉米秸秆青贮料饲养能繁母牛对其受胎率无明显影响（P〉0.05）;育肥牛的日增重分别为1294 g/d和1320 g/d,表明利用皇竹草和抽穗期玉米秸秆青贮料育肥肉牛,其生长速度无明显差异（P〉0.05）。由于皇竹草在低海拔喀斯特山区易于种植,生长期长,产量高,易于加工和青贮,是低海拔喀斯特山区解决肉牛产业发展中青粗饲料来源的有效途径,适宜大面积推广应用。     

Effects of restricted vs. step up dietary adaptation for 6 or 9 days on feedlot performance,feeding behaviour,ruminal and blood variables of Nellore cattle

This study was designed to determine effects of quantitatively restricted intake of the final finishing diet as a means of dietary adaptation compared with diets increasing in concentrate (step up) over periods of 6 and 9 days on feedlot performance, carcass characteristics, feeding behaviour, blood gas profile and rumen morphometrics of Nellore cattle. One hundred twenty 22‐month‐old Nellore bulls (352 ± 20 kg) were randomly allocated in 24 pens and fed for 84 days. The experimental design was a completely randomized block with 2 × 2 factorial arrangement of treatments: adaptation using either step up protocol for 6 days or 9 days or restriction protocol for 6 days or 9 days, where the pen (five bullocks/pen; six pens/treatment) was considered the experimental unit. Cattle adapted by step up protocol had significantly greater average daily gain throughout the study when compared to those adapted by restriction protocol, regardless of adaptation length. During the adaptation period, a greater dry matter intake fluctuation was observed for animals maintained on restriction programme when compared to those adapted to the finishing diets using step up protocol. In addition, a protocol × length interaction for rumenitis scores was observed, where the level of injuries to the ruminal wall was significantly higher for the cattle adapted by restriction protocol for 9 days and lower for animals submitted for 9 days to the step up programme. Likewise, a protocol × length interaction for mitotic index was observed, in which cattle adapted by step up protocol for 9 days had lower numbers of cells in mitosis. Thus, the step up protocol led to better feedlot performance, and based on this fact, the length of 9 days promoted better rumen epithelium adaptation of Nellore cattle to high‐concentrate diets.     

棕榈粕渣发酵饲料养殖肉牛应用效果研究

[目的]评价棕榈粕渣发酵饲料对肉牛养殖效果的影响,为棕榈粕渣发酵饲料产品的研发与应用提供依据。[方法]选用24头夏洛莱牛与当地黄牛的杂交育成牛为试验对象,随机分成Ⅰ、Ⅱ、Ⅲ组与对照组4个组。在育肥期(14~16月龄),对照组试验牛饲喂精料补充料和基础粗饲料(100%玉米秸秆),试验组Ⅰ、Ⅱ、Ⅲ组试验牛饲喂与对照组相同的精料补充料和分别用10%、20%、30%棕榈粕渣发酵饲料替代玉米秸秆的粗饲料,拴系饲养,进行饲养试验。经过分析肉牛的生长性能、健康状况、经济效益,评价其应用效果。[结果]在育肥期,以棕榈粕渣发酵饲料替代部分(10%、20%、30%)玉米秸秆作为肉牛粗饲料能达到同样的育肥效果;育肥过程中对照组及试验组杂交牛存活率均为100%,健康状况良好;各组盈利排序为试验组Ⅲ >试验组Ⅱ >试验组Ⅰ >对照组。[结论]含有棕榈粕渣发酵饲料的肉牛粗饲料可以降低养殖成本、提高经济效益。     

不同水平干苹果渣对育肥牛体外产气量、发酵参数、营养物质消化率和生长性能的影响

[目的] 研究不同水平干苹果渣替代精料补充料中部分能量饲料对西门塔尔育肥牛瘤胃体外产气量、发酵参数、营养物质消化率和生长性能的影响。[方法] 分别采用0、4%、8%、12%、16%干苹果渣替代肉牛精料补充料中部分玉米,应用体外产气法测定各组日粮体外发酵0~72 h的产气量;体外产气试验结束后,测定瘤胃液的发酵参数;体外发酵48 h测定人工瘤胃液营养成分体外消化率;利用4%、8%、12%干苹果渣替代精料补充料中部分玉米,测定饲喂不同替代比例日粮育肥牛的增重指标。[结果] 4%干苹果渣组总产气量显著（P<0.05）高于8%和16%干苹果渣组,各组样品产气主要集中在4~24 h,36~72 h产气量趋于平稳。产气后各组pH值均在正常范围;8%干苹果渣组氨态氮浓度显著（P<0.05）高于12%和16%干苹果渣组;4%和8%干苹果渣组的乙酸、异丁酸、丁酸、异戊酸和戊酸浓度显著（P<0.05）高于其他各组。对照组的干物质、粗蛋白和中性洗涤纤维消化率显著（P<0.05）高于其他各组,8%干苹果渣组酸性洗涤纤维消化率显著（P<0.05）高于其他各组。各组育肥牛的试验期间总增重和日增重差异均不显著（P>0.05）。[结论] 4%干苹果渣替代精料补充料中部分玉米可提高西门塔尔育肥牛瘤胃体外发酵产气量,4%和8%干苹果渣替代精料补充料中部分玉米可提高瘤胃液中氨态氮浓度及挥发性脂肪酸浓度,有利于瘤胃发酵和饲粮消化。     

Extruded urea could reduce true protein source in beef cattle diets

Rumen micro‐organisms are capable of producing microbial protein from ammonia and carbon skeleton, and non‐protein nitrogen (NPN) may be one of the sources of ammonia. Alternative source of NPN is the slow release of ammonia sources in which the product is the extrusion of starch with urea. This work aimed to determine the effects on nutrient intake, ingestive behaviour, digestibility, nitrogen balance, ruminal pH, rumen ammonia nitrogen, volatile fatty acids (VFA) and blood parameters with increased levels of extruded urea (50, 60, 70 and 80 g/100 kg of body weight [BW]) in beef cattle diet. Four rumen cannulated crossbred steers with initial mean weight of 336 ± 47 kg in a 4 × 4 Latin square design were distributed. Diets were formulated with 400:600 g/kg roughage:concentrate ratio on dry matter based and provided once per day, being used whole corn silage as roughage. There were no effects on nutrient intake (kg/day), ingestive behaviour, apparent digestibility, nitrogen balance, volatile fatty acid (VFA) and blood parameters in extruded urea treatment groups. Similar results were observed on time spent on feeding, rumination and idleness. There were positive linear effects (p = 0.022) on rumen pH in the time of 8 hr after feeding and also on plasma concentration of the extruded urea levels (p = 0.039); whereas a linear negative effect (p = 0.030) was observed on ammonia nitrogen for the collection time of 2 hr after feeding. Increased levels of extruded urea could maintain nutrient intake, digestibility, ingestive behaviour, rumen pH and blood parameters in normal conditions. In conclusion, we recommend the extruded urea use with values up to 80 g/100 kg BW in confined beef cattle that receive balanced diets with 140 g/kg of crude protein.     

The effects of protein sources supplemented with urea-treated potato pulp (PP) silage and feeding levels of the PP silage-based concentrate on feed intake, digestibility and ruminal fermentation in beef steers

Six Japanese Black (Wagyu) steers (average initial weight 467 ± 45 kg) fitted with a ruminal cannula were used in a split‐plot design experiment comprising a 3 × 3 Latin square design (whole‐plot) and a randomized block design (subplot). The whole‐plot treatments were three different feeding levels of urea‐treated potato pulp (PP) silage‐based concentrate: 1.00%, 1.75% and 2.50% of body weight (BW) (on a dry matter (DM) basis). The subplot treatments consisted of the concentrate formulated to contain either soybean meal (SBM) as a rapidly rumen‐degraded protein source or corn gluten meal (CGM) as a slowly degraded protein source. Dry matter intake tended to be lower (P = 0.071) for CGM (8.9 kg/day) than for SBM (9.4 kg/day). Protein sources had no significant effect on digestibility and in situ degradation. Ruminal ammonia nitrogen (NH₃‐N) was lower (P = 0.033) for CGM (7.5 mg/dL) than for SBM (9.5 mg/dL). Protein sources did not affect ruminal pH and the total volatile fatty acids (VFA) concentrations. The molar proportions of ruminal acetate and valerate were higher (P = 0.032) for CGM than for SBM. The maximum daily intake of the PP silage‐based concentrate expressed as a percentage of BW was approximately 1.4% of BW. Dry matter intake was higher (P = 0.046) for steers fed at 1.0% of BW of the PP silage‐based concentrate than for steers fed at 1.75% or 2.5% of BW of the concentrate. The feeding levels of the PP silage‐based concentrate had no effect on DM and nutrients digestibility, except for crude protein (CP) digestibility. CP digestibility tended to be lower (P = 0.071) for steers fed at 1.75% of BW of the PP silage‐based concentrate than for steers fed at 1.0% or 2.5% of BW of the concentrate. The feeding levels of the PP silage‐based concentrate also did not affect the in situ degradation parameter of hay and PP silage. The feeding levels of the PP silage‐based concentrate did not affect ruminal pH, NH₃‐N and total VFA concentrations. The molar proportion of acetate was highest for steers fed at 1.0% of BW of the concentrate. In conclusion, in the urea‐treated PP silage‐based concentrate, CGM seems to be more effective than SBM for stabilizing the ruminal NH₃‐N concentration and to be advantageous for fiber digestion in the rumen. The feeding levels of the PP silage‐based concentrate did not change the amount of VFA production in the rumen and the DM digestibility.