Effects of direct-fed microbial supplementation on digestibility and fermentation end-products in horses fed low- and high-starch concentrates

A study was conducted to determine whether direct-fed microbials (DFM) could be used to increase digestibility and minimize the risk of acidosis associated with feeding an increase in the amount of starch fed to horses. Fifteen mature Thoroughbred geldings were randomly assigned to 1 of 3 treatments in a 3 x 3 Latin square design balanced for carryover effects. Within each 26-d period, horses were offered grass hay + low-starch concentrate (LS; 1.2 g of starch x kg of BW(-1) x meal(-1)) from d 1 to 13 and then were abruptly changed to hay + high-starch concentrate (HS; 2.4 g of starch.kg of BW(-1)x meal(-1)) on d 14 continuing through d 26. The DFM treatments were offered in concentrate pellets at a target dosage of 10(8) cfu/(50 kg of BW x d) as follows: no DFM (CON; control), Lactobacillus acidophilus (LAC1; single-species DFM), or a mixture of L. acidophilus, Lactobacillus casei, Bifidobacterium bifidum, and Enterococcus faecium (LAC4; multiple-species DFM). Total feces were collected over 72 h from d 11 to 13 (LS; low dietary starch collection), from d 15 to 17 (AC; abrupt change in dietary starch collection), and at the end of each experimental period, from d 24 to 26 (HS; high dietary starch collection). Data collected consisted of total DM intake and fecal output, fecal pH, fecal acetate and propionate concentrations, and viable numbers of DFM in the feed. With the exception of Fe digestibility, there were no starch x DFM interactions. There was an effect of starch level (P 0.10). Horses supplemented with LAC4 had increased ether extract (P < 0.05) and a tendency for decreased Na (P < 0.10) digestibilities compared with CON horses. All DFM-supplemented horses had increased Cu (P < 0.05) and Fe and numerically increased Zn digestibilities compared with CON horses. Fecal pH decreased (P < 0.05), and fecal propionate concentration increased (P < 0.05) as dietary starch content changed from LS to HS. There was a tendency for elevated fecal pH (P < 0.10) in LAC1 horses compared with CON horses. These results confirm that increasing starch in the equine diet can enhance nutrient digestibility of the diet. Supplementing equine diets with either a single or mixed strain direct-fed lactic acid bacteria had limited effects on nutrient digestibility or on reducing the risk of acidosis associated with feeding high-starch concentrates to horses. The potential response of DFM supplementation should be evaluated when a more acute acidotic state is induced in horses than in the current study.     

不同水平苜蓿添加量对犊牛生长发育、营养物质消化率和瘤胃发酵参数的影响

文章旨在研究犊牛开食料中添加不同含量的苜蓿干草对犊牛生长发育、营养物质消化率和瘤胃发酵参数的影响。试验选择45头刚出生的中国荷斯坦母犊牛,按照体重划分区组,采用完全随机区组试验设计,将新生犊牛分配到3个处理组中,每组15头犊牛。对照组犊牛开食料中不添加苜蓿干草;在试验组Ⅰ犊牛开食料中添加10%的苜蓿干草(干物质基础);试验组Ⅱ犊牛开食料中添加20%的苜蓿干草(干物质基础)。犊牛在60日龄断奶,断奶结束后试验继续进行20 d。试验期间,1～50 d为哺乳期,犊牛饲喂常乳(正常饲喂量)+开食料;51～60 d为断奶过渡期,犊牛饲喂常乳(减量)+开食料;61～80 d为断奶后期,犊牛饲喂开食料。犊牛7日龄时开始饲喂开食料,犊牛14日龄时,在开食料中开始添加苜蓿干草。每天记录开食料采食量,分别于试验第1天、第50天、第80天在早晨饲喂前称重犊牛体重,分别于第50天和第80天在犊牛采食开食料3 h后采集瘤胃液,测定挥发性脂肪酸浓度和NH3-N浓度。于试验最后3 d,采集粪便进行消化试验,测定营养物质消化率。试验结果表明,犊牛开食料中添加苜蓿干草显著提高了犊牛体重、平均日增重和干物质采食量,而且与添加剂量呈线性相关,以20%的添加量组犊牛具有最佳的生长性能,而对犊牛的饲喂效率没有显著影响。犊牛开食料中添加苜蓿干草显著改善了瘤胃发酵功能,增加了瘤胃液pH,提高了瘤胃液乙酸与丙酸的比值。苜蓿干草对犊牛的营养物质表观消化率没有显著影响。因此,本试验结果表明,犊牛开食料中添加20%的苜蓿干草显著提高了犊牛生长性能,改善了犊牛瘤胃发育和发酵功能。     

日粮中不同浒苔添加水平对蛋鸡营养物质表观消化率和盲肠微生物区系的影响

本试验旨在探讨日粮中添加不同水平浒苔对蛋鸡营养物质表观消化率和盲肠微生物区系的影响。选取80只330日龄健康商品代海蓝褐壳蛋鸡,随机分成4组,每组5个重复,每重复4只。分别饲喂浒苔添加量0.0%(对照组)、2.0%(Ⅰ组)、3.0%(Ⅱ组)、4.0%(Ⅲ组)的日粮,试验期为49 d。结果表明:与对照组相比,4%浒苔添加水平能显著提高蛋鸡粗蛋白质、钙、磷表观消化率(P0.05);显著提高蛋鸡盲肠双歧杆菌的数量(P0.05)。因此,在日粮中添加浒苔可提高蛋鸡营养物质表观消化率和改善盲肠微生物区系的作用。适宜添加量建议为4%。     

Effect of protein source and fumaric acid supplementation on apparent ileal digestibility of nutrients by young pigs

Two experiments were conducted to determine the apparent ileal digestibility of DM and N by young pigs fed diets supplemented with different protein sources or organic acids. Pigs were surgically fitted with silicone cannulas at 2 wk of age. Following surgery, pigs were allowed to recuperate with their dams while suckling normally. After weaning at 24 d, pigs were assigned to treatment diets at 28 d of age. A 3-d adjustment and 4-d collection sequence was followed for the duration of the 4-wk experiment. Four treatment diets were fed in each experiment in a weekly rotation until each diet had been fed to each pig. Diet samples and digesta collected through the ileal cannulas were analyzed for chromic oxide (used as an indigestible marker), DM, and N. Pigs in Exp. 1 were fed isolysinic (1.0%) corn-based diets supplemented with casein, soybean meal, soy protein concentrate, or isolated soy protein. Casein addition resulted in improved DM (P less than .001) and N (P less than .05) digestibility but reduced gain (P less than .05) compared with the average of the soy protein sources. Nitrogen from diets formulated with soybean meal was digested more completely (P less than .05) than N from diets based on soy protein concentrate and isolated soy protein. Experiment 2 was an evaluation of the effect of dried skim milk (25%) and fumaric acid (2%) addition on apparent ileal digestibility of N and DM in corn-soybean meal diets. Addition of dried skim milk improved DM (P less than .01) and N (P less than .05) digestibility and daily gain (P less than .001). Fumaric acid supplementation did not affect nutrient digestibility or gain (P greater than .10).     

饲粮中添加紫花苜蓿草粉对蒙古马运动性能及养分表观消化率的影响

本试验旨在探讨饲粮中添加不同水平的紫花苜蓿草粉对蒙古马运动性能及养分表观消化率的影响,试验选用体重、年龄、体尺、运动成绩相近的蒙古马27匹随机分为3组,每个组3个重复,每个重复3匹,1组饲喂基础日粮为对照组,2、3组分别在基础日粮中添加2.5%、5.0%紫花苜蓿草粉,试验开始第20天对各组马匹逐个进行20 km模拟比赛,在赛后0、20 min测定试验马匹的体温、脉搏、呼吸等运动性能,采集粪便测定养分表观消化率。结果表明:(1)试验2、3组平均速度高于1组(P> 0.05);试验2、3组赛后0 min体温低于1组(P> 0.05);试验3组赛后5 min呼吸频率较1组相比降低22.3%(P <0.05);试验3组赛后0、20 min的心率较1组相比分别降低15.3%,33.1%(P <0.05)。(2)试验2、3组的有机物、粗蛋白质、钙、磷表观消化率均高于1组(P> 0.05);试验3组干物质、中性洗涤纤维、酸性洗涤纤维表观消化率较1组相比分别提高10.0%、13.4%、15.5%(P <0.05)。综上,在饲料中添加5.0%紫花苜蓿草粉可提高蒙古马运动性能,有利于运动后生理指标的快速恢复,同时提高养分表观消化率。     

Effects of feeding large amounts of grain on colonic contents and feces in horses

OBJECTIVE: To assess changes in systemic hydration, concentrations of plasma electrolytes, hydration and physical properties of colonic contents and feces, and gastrointestinal transit in horses with access to large amounts of grain. ANIMALS: 6 horses with right dorsal colon (RDC) fistulas. PROCEDURE: In a crossover design, horses were alternately fed 1 of 3 diets: orchard grass hay ad libitum after being adapted to this diet for at least 5 days, orchard grass hay ad libitum and 4.55 kg of grain offered every 12 hours after being adapted to orchard grass hay ad libitum for at least 5 days, or orchard grass hay ad libitum and 4.55 kg of grain offered every 12 hours after being adapted to this diet for at least 5 days. Physical examinations were performed and samples of blood, colonic contents, and feces were collected every 6 hours during a 48-hour observation period. RESULTS: Grain ingestion had several effects, including changes in the concentrations of electrolytes in plasma; RDC contents became more homogenous, dehydrated, foamy, and less dense; RDC contents flowed spontaneously when the cannula was opened; RDC contents expanded when heated in an oven; and feces became fetid and less formed. Horses did not have any clinical signs of colic, endotoxemia, or laminitis. CONCLUSIONS AND CLINICAL RELEVANCE: Changes observed in the colonic contents and feces may be explained by the large amounts of hydrolyzable carbohydrates provided by grain. Access to large amounts of grain may increase the risk of tympany and displacement of the large intestine.     

烟酸对热应激奶牛营养物质表观消化率及血清生化指标的影响

试验选用3头健康的泌乳后期的中国荷斯坦奶牛,采用3×3拉丁方设计,在基础日粮中分别添加0、8、15g/d烟酸,研究日粮添加不同水平烟酸对热应激奶牛干物质采食量、营养物质表观消化率和部分血液生化指标的影响。试验期为63d。结果表明:(1)添加8、15g/d烟酸分别使奶牛的干物质采食量显著提高12.71%和11.20%(P0.05);(2)添加8g/d烟酸能使奶牛营养物质消化率显著提高(P0.05),添加15g/d烟酸对奶牛营养物质消化率有提高的趋势,但差异不显著(P0.05);(3)日粮添加烟酸能够维持奶牛血清皮质醇水平的基本恒定、降低血清胆固醇、甘油三酯水平的趋势。综合分析试验奶牛的干物质采食量、营养物质表观消化率和血液生化指标变化,夏季给奶牛补饲烟酸有助于缓解热应激,适宜的添加量为8g/d。     

Influence of soybean hull supplementation on rumen fermentation and digestibility in steers consuming freshly clipped, endophyte-infected tall fescue

Six steers (288.6 +/- 2.1 kg of BW) fitted with rumen and duodenal cannulas were used in a crossover design to evaluate intake, rumen fermentation, and site of nutrient digestion of freshly clipped, endophyte-infected (E+) Kentucky 31 tall fescue with or without soybean hull (SH) supplementation at 0.60% of BW (OM basis). Steers were placed in metabolism units within an environmentally controlled room and provided with free-choice access to fresh forage, water, and a vitamin/mineral supplement. The spring growth of E+ tall fescue was harvested daily during the experiment. Supplement was fed at 0700 with approximately 65% of the estimated daily forage. To maintain a fresh forage supply, additional forage was stored in a cooler and fed at 1900. Periods were 21 d with 14 d of adaptation and 7 d of digesta sample collection. Chromic oxide was used as a marker of duodenal digesta flow. Duodenal samples were taken 4 times daily with times shifting by 1 h each day to represent all 24 h of a day. Treatments were considered significant at P < 0.05. Supplementation of SH decreased forage OM intake from 1.64 to 1.41% of BW but increased total OM intake from 1.64 to 2.01% of BW. Apparent percentages (53.1%) and quantities (2,786 g/d) of rumen OM disappearance were not affected by supplementation. Percentages of total tract OM disappearance were not different (70.8%). Percentages of apparent rumen NDF disappearance also were not different (65.6%). Percentages of N disappearance were not different. Supplementation of SH resulted in increased total N (34.1 g/d) and microbial N (17.1 g/d) flowing to the duodenum. Rumen pH (6.5) was not affected, and rumen ammonia concentrations exhibited a time x treatment interaction in which SH decreased ammonia for 12 h after supplementation. Total VFA concentrations (103.9 mM) were unaffected. Liquid dilution rate (12.7%/h) and rumen OM fill (4.3 kg) were not different between treatments. Supplementation of SH at a rate of 0.60% of BW (OM basis) to calves consuming fresh E+ tall fescue decreased forage consumption but resulted in greater total intake, greater flow of N to the duodenum, and increased total tract OM disappearance.     

Linseed oil supplementation in diet for horses: Effects on palatability and digestibility

Feed palatability and in vivo apparent digestibility of nutrients were compared in horses fed concentrates in which barley was, or not, partially substituted by 8% linseed oil. According to a cross-over design, three geldings and one stallion were fed at near maintenance level hay plus low or high fat diet (50/50). The last days of each 3-months sub-periods, partial faeces collections were performed and concentrate intake rate was measured to estimate the digestibility and the palatability of the diet. The inclusion of linseed oil did not affect the palatability of the diet and increased significantly (P < 0.05) the apparent digestibility of DM (66.5 vs 64.1%), CF (83.7 vs 57.3%) and NDF (53.0 vs 50.7%) but not of CP and ADF.     

在玉米─大麦─豆粕型饲粮中添加β-葡聚糖酶对生长猪生产性能及营养物质表观消化率的影响

共采用３０ 头２０ 公斤重的杜×长×大生长猪,均分入３ 个处理组,分别饲以玉米－ 豆粕（ＣＳ） 、玉米－ 大麦－ 豆粕（ＣＢＳ） 和玉米－ 大麦－ 豆粕＋ ０－１ ％ β－ 葡聚糖酶（ 酶活性为２－８ 万Ｕ／ 克）（ＣＢＳＥ） 饲粮,饲喂至５０ 公斤,分别测定了猪的生产性能及总能（ＧＥ） 粗蛋白（ＣＰ） 、粗纤维（ＣＦ） 的表观消化率。结果表明：在生长猪的ＣＢＳ饲粮中添加β－ 葡聚糖酶后,对猪的日增重、料重比有改善的趋,从而接近ＣＳ 饲粮的效果,但差异不显著（Ｐ＞ ０－０５） ;但可显著提高猪对饲粮ＧＥ、ＣＦ 的表观消化率（Ｐ≤０－０５） ,对ＣＰ 的表观消化率没有显著的改善作用（Ｐ＞ ０－０５） 。     

饲料中添加紫花苜蓿鲜草对肉牛生长性能及养分表观消化率的影响

为研究紫花苜蓿鲜草对肉牛生长性能及养分表观消化率的影响,采用单因素设计试验,选择体重相近的肉牛90头,随机分成3组,每组3个重复,每个重复10头。1组为空白对照组饲喂基础日粮,2、3组分别在风干物质的基础上添加5%、10%的紫花苜蓿鲜草,预试验10 d,试验期为60 d,在试验期间测定肉牛生长性能和养分表观消化率。结果表明:(1)试验3组的试验末重、平均日增重分别较对照组提高3.30%、14.77%(P <0.05),试验2组和3组的平均日采食量均高于1组(P> 0.05),试验3组的料重比分别较对照组降低7.20%(P <0.05);(2)试验2、3组的粗脂肪、粗灰分、钙、磷的表观消化率均高于1组(P> 0.05);试验3组粗蛋白质、中性洗涤纤维、酸性洗涤纤维表观消化率分别较对照组提高13.85%、18.83%、21.03%(P <0.05)。结论,10%紫花苜蓿鲜草可以提高肉牛的生长性能和养分表观消化率。     

添加酶制剂和膨化处理对生长猪饲粮中脱脂米糠概略养分和矿物质表观消化率的影响

旨在研究添加酶制剂和膨化处理对生长猪饲粮中脱脂米糠概略养分和矿物质在回肠末端及全消化道表观消化率的影响。试验选取4头在回肠末端安装T型瘘管的杜×长×大三元杂交阉公猪,初始体重为(18±1.5)kg。饲喂按2×2因子设计的脱脂米糠、脱脂米糠+酶制剂、膨化脱脂米糠和膨化脱脂米糠+酶制剂4种饲粮,按4×4拉丁方试验安排分4个周期进行消化试验,每个周期10 d。结果表明:(1)在回肠末端,添加酶制剂显著提高了干物质、总能、Fe和Zn的表观消化率(P0.05),且极显著地提高了粗蛋白、灰分、植酸磷、P和Ca的表观消化率(P0.01);膨化处理显著提高了Fe的表观消化率(P0.05),且极显著地提高了植酸磷的表观消化率(P0.01),但显著降低了干物质、有机物和粗脂肪表观消化率(P0.05),且极显著地降低了总能表观消化率(P0.01)。(2)在全消化道,添加酶制剂显著提高了Cu的表观消化率(P0.05),且极显著地提高了灰分、P、Ca和Zn的表观消化率(P0.01);膨化处理显著降低了粗蛋白和粗脂肪的表观消化率(P0.05),且极显著地降低了干物质、有机物、总能、P和Ca的表观消化率(P0.01)。综上所述,生长猪脱脂米糠饲粮中添加酶制剂可以改善养分和矿物质消化率,尤其是在回肠之前;而除矿物质外,膨化处理对米糠饲粮的大多数概略养分消化率有负面影响,两种处理方法对米糠养分的消化利用未显示出协同效果。     

酵母培养物对热应激奶牛泌乳性能和营养物质表观消化率的影响

文章旨在研究炎热夏季条件下日粮中酵母培养物添加水平对荷斯坦奶牛生产性能和营养物质表观消化率的影响。试验选取60头中国荷斯坦奶牛,按照胎次、泌乳天数和产奶量进行区组设计,随机分为3组,每组有20头奶牛。对照组奶牛饲喂基础日粮,试验1组奶牛和试验2组奶牛分别在基础日粮的基础上补充饲喂100 g/d·头和200 g/d·头的酵母培养物。预试期2周,正试期8周。试验期间每天记录产奶量,每周采集奶样测定乳成分,正试期最后3 d进行消化试验,采用酸不溶灰分法测定营养物质表观消化率。试验期间,每天大部分时间牛舍的平均温湿指数大于72,意味着奶牛试验期间遭受不同程度的热应激影响。酵母培养物显著提高热应激泌乳早期奶牛的干物质采食量,以饲喂200 g/d·头的奶牛具有最大干物质采食量(P <0.05)。酵母培养物显著增加遭受热应激的泌乳早期奶牛的产奶量,本试验条件下呈线性增加(P <0.05)。酵母培养物显著提高遭受热应激的泌乳早期奶牛的乳糖率,本试验条件下呈线性增加(P <0.05)。遭受热应激的泌乳早期奶牛补充饲喂酵母培养物对其他乳成分无显著影响(P> 0.05)。酵母培养物显著提高热应激条件下泌乳早期奶牛的干物质、粗蛋白质和中性洗涤纤维的消化率(P <0.05),而对粗脂肪和酸性洗涤纤维的消化率无显著影响(P> 0.05)。因此,酵母培养物饲喂遭受热应激的泌乳早期奶牛可以显著增加其干物质采食量和提高产奶量,并改善营养物质消化率,本试验中以200 g/d·头的饲喂剂量最佳。     

三颗针提取物对断奶仔猪生长、养分消化率和血清指标的影响

研究了日粮中添加抗生素或不同剂量三颗针提取物对断奶仔猪生长、养分表观消化率和血清指标的影响。选用128头体质量相近的三元杂交断奶仔猪(杜×长×大),随机分为4组,每组4个重复,每个重复8头猪,公母各半。对照组饲喂添加100mg/kg土霉素的日粮,3个试验组日粮中分别添加三颗针提取物200、500和1000mg/kg。试验结果表明:与添加土霉素相比,添加200mg/kg和500mg/kg三颗针提取物组仔猪日增重显著提高,500mg/kg三颗针提取物组仔猪料重比和腹泻率显著降低;添加三颗针提取物各组粗蛋白质、粗脂肪和有机物表观消化率与添加土霉素组间均没有显著差异,但以500mg/kg组较高,500mg/kg和1000mg/kg三颗针提取物组总磷表观消化率显著高于200mg/kg组和土霉素组,500mg/kg三颗针提取物组仔猪钙表观消化率显著高于土霉素组;200mg/kg和500mg/kg三颗针提取物组仔猪血清ALT、AST活性和TP含量显著高于土霉素组,土霉素组显著高于1000mg/kg组,土霉素组血清GLU含量显著高于添加三颗针提取物组。结果表明,断奶仔猪日粮中添加三颗针提取物能够减少仔猪腹泻、提高仔猪生长性能,达到或超过添加土霉素的促生长效果。日粮中添加500mg/kg的三颗针提取物有利于提高仔猪对日粮的养分表观消化率,提高机体代谢和抗应激能力。     

Chitosan associated with whole raw soybean in diets for Murrah buffaloes on ruminal fermentation,apparent digestibility and nutrients metabolism

This study aimed to investigate the effects of chitosan and whole raw soybean on nutrient intake, apparent digestibility, nitrogen utilization, microbial protein synthesis, blood metabolites, feeding behavior, ruminal fermentation, digesta kinetics, and reticular flow of nutrients of buffaloes. Four ruminally‐cannulated Murrah buffaloes (351 ± 15 kg of initial BW) were randomly assigned according to a 4 × 4 Latin square design. Treatments were arranged as 2 × 2 factorial arrangement: the first factor was whole raw soybean (WRS), and the second factor was chitosan (CHI) with or without their inclusion in diets. Intake and apparent digestibility of ether extract (p < .01; p = .04, respectively), non‐fiber carbohydrates intake (p = .03) and apparent ruminal digestibility of dry matter (p = .01) were affected by diets. An interaction effect or tendency was observed for microbial nitrogen (p = .09), concentrations, ruminal ammonia nitrogen (p = .05), total volatile fatty acid (p = .03). Association of chitosan with whole raw soybean has potential effects as a modulator of rumen fermentation; therefore, chitosan can be applied as an alternative non‐ionophore for Murrah buffaloes.     

不同亚油酸来源的日粮以绵羊瘤胃发酵和营养物质表观消化率的影响

研究探讨日粮添加花生油、玉米油和大豆油对绵羊瘤胃发酵和营养物质表观消化率的影响.选取4只雄性、健康且安装有永久性瘤胃瘘管的成年东北半细毛羊×陶赛特杂交绵羊,体重(40±1)kg,采用4×4拉丁方试验设计,预饲期10 d,正试期6 d,4个处理组分别为不添加油脂组(CK组)、添加4%花生油(PO组)、2.84%玉米油(CO组)和2.86%大豆油(SO组)的加油组,日粮精粗比均为40:60,经测得3个加油组亚油酸水平一致.结果表明:添加植物油后,对绵羊瘤胃液pH值、NH3-N浓度、VFA没有影响(P>0.05),花生油处理组原虫数量比对照组降低了42.18%(P<0.05),玉米油和大豆油处理组原虫数量分别比对照纽降低28.07%、29.81%(P>0.05);对DM、CP和NDF的瘤胃动态降解率没有影响(P>0.05);对日粮DM、CP、NDF和ADF的全消化道表观消化率没有影响,显著提高了EE的全消化道表观消化率(P<0.05).日粮添加植物油对瘤胃发酵没有负面影响,并显著提高了EE的全消化道表观消化率.     

玉米蛋白饲料对民猪杂交猪生长性能和养分表观消化率的影响

试验旨在研究猪饲粮中添加不同水平的玉米蛋白饲料对民猪杂交猪生长性能和养分表观消化率的影响。将24头试验猪(体重接近)随机分为3个组,每组有8个重复,每个重复1头猪。对照组仅饲喂基础饲粮,试验组的饲粮以玉米蛋白饲料替代玉米和豆粕,替代比例分别是15%、30%,试验全期30 d。结果表明,15%玉米蛋白饲料替代组的日增重较对照组显著提高18.40%(P<0.05);15%玉米蛋白饲料替代组的料重比最低,较对照组显著降低8.31%(P<0.05),与30%玉米蛋白饲料替代组相比显著降低了11.11%(P<0.05)。试验1组和对照组之间的粗蛋白质消化率无显著差异,但试验2组较试验1组显著下降2.25%(P<0.01)。在粗脂肪消化率方面,试验2组较对照组显著降低了3.61%(P<0.05)。与对照组相比,试验组2的钙和磷的消化率分别显著下降7.11%(P<0.05),4.52%(P<0.05)。添加玉米蛋白饲料对民猪杂交猪的干物质和能量的消化率无显著影响。本试验条件下,日粮中添加15%玉米蛋白饲料对民猪杂交猪的采食量和日增重有促进作用,过高比例(30%)则会影响育肥猪的生长速度,降低其对粗蛋白质、粗脂肪、钙和磷的表观消化率。     

Comparison of digestibility, passage rate and rumen fermentation between sika deer (Cervus nippon) and cattle fed alfalfa hay cubes

Five female sika deer and three male Holstein cattle were offered alfalfa hay cubes at 2% (deer) and 2.5% (cattle) of bodyweight, respectively. The passage rate through the digestive tract, digestibility and rumen fermentation of the animals were determined. The rate of ruminal passage was higher and the total mean retention time in the digestive tract was shorter in deer than in cattle. In addition, the rate of post‐ruminal passage in deer was lower. The digestibilities of dry matter, organic matter, crude protein and fiber in deer were significantly lower than in cattle (P < 0.05). The concentration of total volatile fatty acids in the rumen was significantly higher in deer than in cattle. The molar percentage of acetic acid was lower and that of valeric acid was higher in deer (P < 0.05). The number of protozoa was somewhat higher in deer. These results suggested that the lower digestibility in deer might be a result of the shorter retention time in the digestive tract.     

Effect of live yeast culture supplementation on apparent digestibility and rate of passage in horses fed a high-fiber or high-starch diet

Eight crossbred male horses aged 12 +/- 5 yr and with BW of 305 +/- 18 kg were used in pairs in a 4 x 4 Latin square design with 4 ground and pelleted diets. Each pair included a cecum and right ventral colon-fistulated animal and a cecal-fistulated animal. The 4 horse diets were a high-fiber diet (HF+0) based on dehydrated alfalfa, a high-starch diet based on barley and wheat bran (HS+0), and the HF or HS diets supplemented with Saccharomyces cerevisiae (SC) CBS 493.94 (HF+SC and HS+SC). The probiotic preparation contained 4.5 x 10(9) cfu/g of live yeast mixed with the culture medium, and was top-dressed onto the feed pellets at a rate of 10 g/d, equally distributed between the 2 daily meals. All 4 diets were offered in the same quantities (18.0 g of pelleted feed DM + 3.5 g of long wheat straw/kg of BW per d). Each of the 4 experimental treatments was divided into a 21-d period of diet adaptation followed by a 10-d period of total fecal collection for digesta flow rate and apparent digestibility measurements. Three markers were used to measure mean retention time (MRT) of the feed particles: Yb bound to the pelleted feeds for MRT in the whole digestive tract (MRT(Yb)), Eu bound to the pelleted feeds, and Dy bound to the fecal particles for MRT in the hindgut (MRT(Eu) and MRT(Dy)). Apparent digestibilities of DM, OM, and CP were greater (P < 0.001) in the HS than HF diet, independently of SC supplementation, whereas ADF digestibility was greatest in the HF diet (P = 0.035). Cellulolytic activity estimated through the in vitro disappearance rate of the dietary ADF fraction (IVAD(ADF)) was less (P < 0.001) in the HS than the HF diet. There was no dietary effect on NDF digestibility due to the longer MRT(Eu) of small particles in the hindgut (P = 0.036), which compensated for the lower fibrolytic activity expressed per unit of time in the HS compared with the HF diet. Supplementation with SC improved ADF digestibility (P = 0.038) and stimulated DM (P = 0.030) and NDF (P = 0.038) intakes, but had no effect on the MRT of solid digesta. The absence of any significant diet x SC interaction supports the strategy of using SC to stimulate cellulose digestion and improve the nutritional status of horses under both HF and HS diets.