几种中草药对绵羊瘤胃发酵、抗氧化功能和营养物质消化率的影响

本研究包括2个试验。试验一,采用单因素随机区组试验设计研究了黄芪、党参、女贞子对绵羊屠宰体增重和抗氧化功能的影响。试验共4个处理,含3种中草药和1个对照组。每个处理4个重复,每个重复1只羊。中草药添加量为6 g/d。结果表明,女贞子组提高了绵羊屠宰体增重(P<0.05),改善了绵羊血液抗氧化功能,提高了谷胱甘肽还原酶和超氧化物歧化酶活性,降低了血浆丙二醛含量(P<0.05)。其他组对绵羊屠宰体增重和血液抗氧化功能影响不显著(P>0.05)。试验二,采用4×4拉丁方试验设计研究了女贞子提取物对绵羊瘤胃发酵和血液生化指标的影响。试验分4个处理,女贞子提取物的添加量分别为0、100、300 mg/kg和500 mg/kg。结果表明:添加量为300mg/kg和500 mg/kg组在晨饲后2、4、6、8 h显著提高了绵羊瘤胃液总挥发性脂肪酸浓度和丙酸的浓度,降低了瘤胃液氨态氮的浓度和血浆尿素氮的浓度。300 mg/kg和500 mg/kg组显著提高了日粮有机物质和干物质表观消化率(P<0.05)。     

Prediction of nutritive values in grass silages: I. Nutrient digestibility and energy concentrations using nutrient compositions and fermentation characteristics

Grass silages (n = 136) were selected from commercial farms across Northern Ireland according to their pH, ammonia nitrogen, DM, and predicted ME concentration. Each silage was offered to four sheep as a sole feed at maintenance feeding level to determine nutrient digestibility and urinary energy output. Dry matter concentration was determined as alcohol-corrected toluene DM and was subsequently used as the basis for all nutrient concentrations. The objectives were to use these data to examine relationships between nutritive value and nutrient concentration or fermentation characteristics in silages and then develop prediction equations for silage nutritive values using stepwise multiple regression techniques. The silages had a large range in quality (DM = 15.5 to 41.3%, ME = 7.7 to 12.9 MJ/kg of DM, pH = 3.5 to 5.5) and a relatively even distribution over the range. There was a positive relationship (P < 0.001) between silage GE and DE or ME concentration. Digestible OM in total DM (DOMD); ME/GE; and digestibility of DM, OM, and GE were positively related (P < 0.05) to CP, soluble CP, ether extract, lactic acid concentration, and lactic acid/ total VFA, whereas they were negatively related (P < 0.05) to ADF, NDF, lignin, individual VFA concentration, pH, and ammonia N/total N. Concentrations of DE and ME and digestibility of CP and NDF had similar relationships with those variables, although some relationships were not significant. Three sets of multiple prediction equations for DE and ME concentration; ME/ GE; DOMD; and digestibility of DM, OM, GE, CP, and NDF were therefore developed using three sets of predictors. The first set included GE, CP, soluble N/total N, DM, ash, NDF, lignin, lactic acid/total VFA, and ammonia N/total N; the second set excluded soluble N/ total N and lignin because they are not typically measured; the third set further excluded the fermentation data. The R2 values generally decreased with exclusion of predictors. The second and third sets of equations, except for NDF digestibility, were validated using the mean-square-prediction-error model and an independent grass silage data set published since 1977 (n = 17 [DM digestibility] to 28 [DOMD and OM digestibility]). The validation indicated that the equations developed in the present experiment could accurately predict DE and ME concentrations and DE/GE and ME/GE in grass silages.     

同/异型发酵乳酸菌对全株玉米青贮营养成分和瘤胃降解特征的影响

以新饲玉10号全株青贮玉米为研究材料,旨在探究同/异型发酵乳酸菌对其主要营养成分和瘤胃降解率特征的影响。采用真空袋法调制青贮,共设计4个发酵处理,分别为不添加任何菌剂(CK);复合同型发酵乳酸菌植物乳杆菌+戊糖片球菌(T),添加量为1∶1,1×10^5 cfu·g^-1;异型发酵乳酸菌布氏乳杆菌(Y),添加量为1×10^5 cfu·g^-1;复合同、异型发酵乳酸菌(TY),添加量为1∶1∶1,1×10^5 cfu·g^-1。通过对模拟开窖60 d主要营养成分和绵羊瘤胃降解特征参数的分析。结果表明:干物质(DM)、中/酸性洗涤纤维(N/ADF)、可溶性碳水化合物和粗脂肪含量最优均为Y处理,粗蛋白和淀粉含量各试验处理均极显著高于CK处理(P<0.01),粗灰分含量最高为CK处理。DM和NDF有效降解率按高低排序均为T和Y处理>CK和TY处理(P<0.01)。有机物(OM)有效降解率最高为Y处理(P=0.003)。各处理ADF有效降解率间差异不显著(P>0.05)。说明玉米青贮中Y处理可显著增加开窖60 d时各营养成分含量(粗灰分除外),且显著提高DM和OM有效降解率,TY处理可显著提高NDF有效降解率。综合营养成分和有效降解率12项指标进行隶属函数评价,各处理按优劣排序为:Y处理>T处理>TY处理>CK处理。     

肉用绵羊饲粮营养物质消化率和代谢能预测模型的研究

本试验旨在建立肉用绵羊饲粮营养物质消化率和代谢能(ME)的预测模型。选用66只体重为(45.0±2.0)kg的体况良好的杜泊×小尾寒羊F1代杂交肉用羯羊,随机分为11个处理,每个处理6个重复,每个重复1只羊。采用随机区组设计,分别测定11种不同粗饲料组成的饲粮的营养物质含量,通过物质代谢试验和气体代谢试验测定这11种饲粮的营养物质消化率、消化能(DE)及ME,在分析饲粮营养物质含量、可消化营养物质、DE和ME的基础上,筛选出最佳估测因子并建立估测方程。结果表明:饲粮干物质(DM)、有机物(OM)、粗蛋白质(CP)、总能(GE)消化率与饲粮中CP、GE和OM含量呈显著或极显著正相关(P0.05或P0.01),与中性洗涤纤维(NDF)含量呈显著负相关(P0.05);饲粮NDF消化率与饲粮中DM、OM、CP、GE含量达到显著或极显著负相关(P0.05或P0.01),与NDF含量达到极显著正相关(P0.01)。利用饲粮中营养物质含量对ME进行估测的最佳方程为ME=-49.593+0.594OM-0.107NDF(R2=0.949,P0.01)。由此得出,饲粮营养物质消化率、ME与营养物质含量均有较强的相关性,可通过营养物质含量对饲粮的营养物质消化率、ME进行合理估测。     

Comparative utilization of warm- and cool-season forages by cattle, sheep and goats

The quality of different classes of forage hay (C3, C4 grasses and legumes) was determined in intake and digestibility trials with mature cattle, sheep and goats. For all nine hays, DM and NDF digestibility by cattle and goats was higher (P less than .05) than by sheep, with no differences due to forage class. Cattle had a higher (P less than .01) DM intake than sheep or goats averaged across forage (92.6 vs 65.8 and 68.6 g/kg BW.75); hay intake was highest on legume, with no difference between C3 and C4 grasses. Mean NDF intake by cattle was greater than by sheep or goats (58.7 vs 39.6 and 42.6 g/kg BW.75); NDF intake for all animal species decreased in the order C4 grass greater than C3 grass greater than legume. Particle passage rates did not differ (P greater than .05) with forage class but were higher (P less than .02) for sheep and goats than for cattle. Prefeeding ruminal DM fill values, determined by emptying, were 10.6, 15.0 and 19.9 g/kg BW1.0 for alfalfa, orchardgrass and switchgrass hays fed to cattle, and 11.2, 11.3 and 16.5 g/kg BW1.0 for the same hays fed to sheep. Estimated turnover times for DM and NDF were shorter (P less than .05) for sheep than for cattle; DM turnover was longer for switchgrass than for alfalfa and orchardgrass, with no forage differences in NDF turnover between these two animal species. Results show that goats were superior to sheep in NDF digestion.     

Effect of exogenous fibrolytic enzyme on ruminal fermentation and digestibility of alfalfa and rye-grass hay fed to lambs

This experiment was carried out to study the effect of a directly fed exogenous fibrolytic enzyme on intake and digestion of DM, OM, protein, NDF, ADF, and hemicellulose of alfalfa and ryegrass hay by sheep. Four diets were randomly assigned to four ruminally cannulated lambs using a 4 x 4 Latin square design, repeated in time, with a factorial arrangement (2 x 2) of diets: 1) alfalfa hay; 2) alfalfa hay + exogenous fibrolytic enzymes (enzyme); 3) ryegrass hay; and 4) ryegrass hay + enzyme. Lambs consumed more DM and OM from alfalfa than from ryegrass hay (P < 0.001). The ADF intake was not different between the hays, but NDF intake was lower for alfalfa (P < 0.001). For both hays, the enzyme increased intake of DM (P < 0.01), as well as OM and CP (P < 0.05); however, NDF and ADF intake were not changed. Alfalfa hay had higher apparent digestibility of DM, OM, and CP (P < 0.001), but lower digestibility for NDF, ADF, and hemicellulose. The enzyme increased apparent digestibility of CP, hemicellulose (P < 0.05), and NDF (P < 0.10) for alfalfa. Also, for both hays, the enzyme improved N balance because lambs retained more N (P < 0.05). The enzyme increased (P < 0.05) total VFA concentration (3 and 6 h) for both hays. Results from this trial indicate that directly fed exogenous fibrolytic enzymes may change ruminal fermentation, intake, and digestibility of forages with different nutritive value.     

中草药抗雏鸡冷应激机理的研究

选用附子、女贞子、干姜3味中草药,对雏鸡进行了慢性（5、10 d）冷应激（12±1）℃实验,通过NO、谷胱苷肽过氧化物酶（GSH-PX）、红细胞及白细胞数量变化探索中草药抗雏鸡冷应激的机理。结果表明,应用附子后雏鸡血清和下丘脑中NO含量显著下降（P〈0.01）,而GSH-Px活性、红细胞和白细胞数量显著升高（P〈0.01）。表明附子可使冷应激雏鸡NO含量、GSH-Px活性发生变化,具有明显抗冷应激的作用。     

The effect of maize silage type on the performances and methane emission of dairy cattle

To examine whether type of maize silage is important for milk production performances, maize silage LG30224 (LG) was compared with Falkone (FA), the latter having a 4.0% points lower rumen NDF digestibility and 19 g/kg dry matter (DM) more starch. To bridge the lower energy content of FA, a third treatment was involved by adding maize meal (MM) in a ratio of 92/8 on DM (FA+MM). Maize and grass silage were fed ad libitum in a ratio of 65/35 on DM basis. Concentrates were supplemented individually to meet energy and protein requirements. The experiment was set up as a Latin square with three groups of nine Holstein cows during three periods of 3 weeks. In the last 2 weeks of each period, DM intake (DMI) and milk performances were measured. Each group included one cannulated cow to study effects on rumen fermentation. During the last 4 days of each period, two cows from each group were placed in gas exchange chambers to measure nutrient digestibility and methane production. Total DMI was higher (p < 0.05) for FA+MM (20.8 kg/day) than for FA (20.3 kg/day), while DMI for LG was intermediate (20.6 kg/day). Treatment did not affect milk production nor composition, whereas fat–protein‐corrected milk was higher for LG (30.5 kg/day) and FA+MM (30.3 kg/day) than for FA (29.9 kg/day). The ration did not affect pH nor volatile fatty acid composition in the rumen. Further, total tract digestibility of OM, crude protein, NDF and starch did not differ among treatments. The ration with LG gave higher methane production per day and per kg NDF intake than both rations with FA, but the difference was not significant when expressed per kg DMI or FPCM. Thus, maize silage type is of little importance for milk production if energy and physical structure requirements are met.     

Prediction of nutritive values in grass silages: II. Degradability of nitrogen and dry matter using digestibility, chemical composition, and fermentation data

One hundred thirty-six perennial rye-grass silages with wide variations in quality were evaluated for N and DM degradability in three beef steers offered grass silage of medium quality ad libitum. The silages were incubated in the rumen of each animal in triplicate for 0, 6, 12, 24, 48, and 72 h, respectively. The disappearance rates of N or DM were used to calculate the readily soluble fraction ("a" value), potentially degradable fraction ("b" value), and the fractional degradation rate of"b" ("c" value). The effective degradability (P) of N or DM was then estimated assuming a ruminal outflow rate of 0.02, 0.05, or 0.08/h (P0.02, P0.05, or P0.08). The objective was to use these data to develop prediction equations for N and DM degradability in grass silages. There were considerable variations in "a," "b," and "c" values and the P0.02, P0.05, or P0.08 of N and DM (e.g., the P0.02 of N ranged from 75.0 to 93.4% and the P0.02 of DM from 51.5 to 82.5%). The P0.02, P0.05, or P0.08 of N and DM were negatively related (P < 0.001) to ADF, NDF, and lignin concentrations but positively related (P < 0.001) to protein fractions (CP, soluble CP, and true protein concentrations) and digestibility of DM, OM, GE, CP, and NDF and digestible OM in the total DM (measured with sheep). The N and DM degradability data were also positively related to silage lactic acid concentration, but the relationships between DM degradability data and pH, ammonia N/total N, and VFA concentration in silages were negative (P < 0.05). Several sets of prediction equations (linear and multiple) were thus developed for N and DM degradability using CP or NDF concentration, "a" value or digestibility data as primary predictors, together with or without other nutrient concentration and silage fermentation variables. All these relationships were highly significant (P < 0.001), and each predictor had a significant effect on the relationship (P < 0.05). The R2 values in multiple regression for N and DM degradability were generally over 0.70 and higher than in linear regression equations. Four equations were also developed to convert N and DM degradability at a given ruminal outflow rate, predicted using the above-mentioned equations, to their counterparts at any ruminal outflow rate (0.02 to 0.10/h), respectively.     

奶牛日粮中不同水平酵母硒对表观消化率的影响

本试验选取8头体况、奶产量、泌乳天数相近的奶牛，采用4×4拉丁方设计分为4组分别添加4种不同的预混料：对照组不添加酵母硒而添加亚硒酸钠，Se含量为0.3 mg/kg日粮，处理组添加酵母硒，硒水平分别为0.3、0.45、0.6 mg/kg日粮，试验期全天收集牛粪，对常规营养成分进行测定。结果表明：与对照组相比，添加酵母硒0.45 mg/kg组可以提高奶牛对OM、NDF、ADF、纤维素（CEL）、半纤维素（HC）、钙、磷的表观消化率（P<0.01）和粗蛋白质的消化率（P<0.05）；和其他酵母硒处理组相比，0.45 mg/kg组的养分表观消化率也较高。     

The nutritional value of peanut hay (Arachis hypogaea L.) as an alternate forage source for sheep

The aim of this study was to evaluate the nutritional and feeding value of peanut hay (Arachis hypogaea L.) produced under tropical environment as an alternate forage resource for sheep. Peanut hay was appreciably high in crude protein [CP; 105 g/kg dry matter (DM)] and lower in neutral detergent fiber (NDF; 466 g/kg DM). Moreover, peanut hay was rich in Ca (12 g/kg DM) and P (1.7 g/kg DM). A feeding trial was conducted to investigate the effect of substituting wheat straw with peanut hay on nutrient intake, digestibility, and N utilization. Four adult Ramghani (Kaghani × Rambouillet) wethers (60?±?2.5 kg body weight) were randomly assigned to the four dietary treatments according to a 4?×?4 Latin square design. The four rations were formulated on isonitrogenous and isocaloric bases and differed in the proportion (in grams per kilogram DM) of wheat straw/peanut hay, i.e., 700:0, 460:240, 240:460, and 0:700. The replacement of wheat straw with peanut hay increased the intakes of DM (P?<?0.001), NDF (P?<?0.01), and N (P?<?0.001). Moreover, apparent in vivo digestibility of DM, NDF, and CP increased (P?<?0.001) with the increasing proportion of peanut hay in the ration. Nitrogen retention in the body increased (P?<?0.01; 3.2 to 8.1 g/day) with the replacement of wheat straw with peanut hay. These findings showed that substitution of wheat straw with peanut hay can improve DM and nutrients intake, digestibility, and N retention in sheep.     

不同蛋白和中性洗涤纤维水平对瘤胃发酵、消化和微生物蛋白合成的影响

以3头装有瘤胃瘘管的干奶牛作为瘤胃液供体,用体外培养法研究不同日粮蛋白和中性洗涤纤维(NDF)水平对瘤胃发酵、消化和微生物蛋白合成的影响。采用2×3双因子完全随机设计,粗蛋白水平14%、16%和18%,NDF水平为32%和36%。体外发酵后2、4、6、12、24 h取瘤胃液测定pH、NH3-N浓度和微生物蛋白含量,发酵结束后测定饲料中干物质(DM)、NDF和酸性洗涤纤维(ADF)消化率。结果表明:随着蛋白水平升高,瘤胃发酵pH有增加趋势(P=0.079),显著提高NDF和ADF消化率和细菌蛋白合成量(P<0.05),但不影响DM消化率和原虫蛋白的合成量(P>0.05);日粮中NDF水平显著影响瘤胃pH、NH3-N浓度和ADF消化率(P<0.05),但不影响DM和NDF消化率以及微生物蛋白的合成量(P>0.05)。本试验条件下,日粮中16%CP和32%NDF组可在一定程度上促进瘤胃发酵,提高纤维消化率以及微生物蛋白的合成量。     

花生秧作为肉用绵羊单一粗饲料有效能值的测定与估测

本试验旨在用套算法和插值法测定与估测肉用绵羊花生秧有效能值,确定替代法中饲粮中适宜花生秧替代比例,为单一秸秆饲料有效能值的测定与估测提供方法学上的参考。选用体重为(45.00±1.96)kg的体况良好的杜泊×小尾寒羊F1肉用成年羯羊54只,采用随机区组设计,分为9组,饲粮分别为基础饲粮、全花生秧饲粮和分别以10%、20%、30%、40%、50%、60%、70%花生秧替代基础饲粮的试验饲粮,每组6个重复,每个重复1只羊。预试期10 d,正试期9 d,其中气体代谢试验3 d,消化代谢试验6 d。结果表明:1)全花生秧饲粮组花生秧干物质(DM)表观消化率与20%、30%、40%组间差异不显著(P0.05),显著高于其他各组(P0.05)。全花生秧饲粮组花生秧有机物(OM)表观消化率与20%组差异不显著(P0.05),但显著高于其他各组(P0.05)。全花生秧饲粮组花生秧总能(GE)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)、粗脂肪(EE)表观消化率显著高于10%组(P0.05),粗蛋白质(CP)表观消化率显著低于10%组(P0.05),与其他各组间差异不显著(P0.05)。2)花生秧消化能(DE)、代谢能(ME)均具有相同的规律,即全花生秧饲粮组DE、ME(8.57、6.69 MJ/kg DM)与20%(8.22、6.58 M J/kg DM)、30%(8.02、6.50 M J/kg DM)、40%组(8.10、6.52 M J/kg DM)差异不显著(P0.05),但显著高于其他组(P0.05)。3)插值法求得花生秧M E"真值"为6.62 M J/kg DM,接近于套算法得到的花生秧ME。综合得出,套算法可以用于肉用绵羊估测花生秧(单一粗饲料)的DE和M E;用套算法测定花生秧秸秆类粗饲料有效能值,其在饲粮中的适宜替代比例为20%~40%。     

Effects of corn particle size on nutrient utilization in pigs evaluated under optimal and heat stress conditions

The effects of corn particle size on nutrient digestibility and energy utilization in pigs were determined under optimal (experiment 1, 25?±?1 °C) or heat stress (experiment 2, 37?±?1 °C) conditions. In Exp. 1 and 2, five experimental diets were tested using a 5?×?5 Latin square design involving five barrows (Landrace × Yorkshire × Duroc, average initial body weight of 30?±?1 kg and 45.0?±?1.8 kg, respectively, in individual metabolic cages). Dietary treatments were as follows: 200-, 300-, 400-, 600-, 800-μm corn particle sizes obtained by mesh screens. Under optimal thermal conditions, digestibility of dry matter (DM) and crude fiber (CF) from 200-μm diet was higher (P?<?0.05) compared to that from the 300-μm and 400-μm diets. The digestibility of crude protein (CP) and ether extract (EE) was the highest (P?<?0.05) at the 200-μm particle size. The apparent total tract digestibility of energy was significantly higher (P?<?0.05) on the 200-μm diet. Under heat stress, digestibility of CF when corn was ground to 600 μm was higher (P?<?0.05) compared to 300 and 400 μm. Digestibility of NDF and ADF was the highest (P?<?0.05) at 600-μm corn particle size. In conclusion, grinding corn to 200-μm corn particles had a positive effect on DM, CP, EE, and CF under optimal thermal condition, while the 600-μm corn particle size had positive effects on digestibility of CF, NDF, and ADF than 200-μm corn particle size under heat stress.

     

Effect of genotype on chemical composition,ruminal degradability and in vitro fermentation characteristics of maize residual plants

The objective of this study was to determine the changes to residual plant feeding value of early‐ and late‐maturing maize varieties. The influence of the cell wall carbohydrate composition, in terms of neutral and acid detergent fibre (NDF and ADF) content, NDF and dry matter (DM) degradability, and in vitro organic matter digestibility and gas production on the feeding value of a range of maize genotypes, was measured. The different genotypes were allotted into two maturity groups (MG I – early to mid‐early: S210‐S240; MG II – mid‐late to late: S 250‐S280) and harvested at four different harvest dates (depending on the DM content of the kernels). The maize varieties of MG I had lower NDF and ADF contents and higher ruminal DM degradability, in vitro digestibility and gas production and thus a higher feeding value than MG II at the same stage of physiological maturity. A strong negative relationship between NDF content and the ruminal DM degradability (r = ?0.81) was observed. The data indicate that the early‐maturing varieties permit a larger flexibility in harvesting due to a longer period of starch inclusion into the kernel whilst simultaneously maintaining a good supply of rumen‐available fibre. Conclusively, the higher feeding value of the early‐maturing varieties, based on lower NDF and high DM digestibility, permits more flexibility in the harvesting period over the later‐maturing varieties.     

Effects of dietary nonprotein nitrogen on performance, digestibility, ruminal characteristics, and microbial efficiency in crossbred steers

Two trials were conducted to evaluate the effects of dietary NPN levels on animal performance, diet digestibility, ruminal characteristics, and microbial efficiency. Experiment 1 was conducted with 24 Holstein x Nellore crossbred steers (350 +/- 20 kg of BW) distributed in 6 blocks to evaluate intake and digestibility of nutrients and performance. The diets consisted of 70% corn silage and 30% concentrate (DM basis) and were formulated to contain 12.5% CP (DM basis). Treatments consisted of 0, 15.5, 31, and 46.5% of dietary N as NPN. There were no treatment differences in the daily intakes of DM (P = 0.47), OM (P = 0.60), CP (P = 0.24), nonfiber carbohydrates (NFC; P = 0.74), or TDN (P = 0.63); however, NDF intake decreased linearly as NPN increased (P = 0.02). Additionally, no effects of NPN were observed on apparent total tract digestibility of DM (P = 0.50), OM (P = 0.53), NDF (P = 0.63), or NFC (P = 0.44). The apparent total tract digestibility of CP increased linearly (P = 0.01), but ADG (1.14 kg/d) was not influenced (P = 0.96) as NPN increased. In Exp. 2, 4 ruminally and abomasally cannulated steers (300 +/- 55 kg of BW) were fed the same diet used in Exp. 1 to evaluate the effects of NPN levels on intake and digestibility of nutrients, ruminal characteristics, and microbial efficiency. There were no differences in the daily intakes of DM (P = 0.22), OM (P = 0.17), CP (P = 0.31), NDF (P = 0.29), or TDN (P = 0.49). However, NFC intake increased linearly (P = 0.02), and there was a quadratic effect (P = 0.01) on intake of ether extract as NPN increased. Ruminal digestibility of CP increased linearly (P = 0.01) with the increase of dietary NPN. There were no differences (P >or= 0.28) in microbial protein synthesis and microbial efficiency among the treatments. The results of these trials suggest that dietary NPN levels (up to 46.5% of total N) can be fed to crossbred steers receiving corn silage-based diets without affecting their growth performance or ruminal protein synthesis.     

利用尼龙袋法比较3个全株玉米品种青贮前后肉牛瘤胃降解特性

本试验旨在利用尼龙袋法比较不同品种全株玉米青贮前后瘤胃降解特性的差异.试验采用2×3双因素试验设计,选择玉米7367号、玉米7377号、玉米7387号3个全株玉米品种为研究对象,采用尼龙袋法比较3种全株玉米青贮前和青贮后的营养成分和瘤胃降解特性,旨在探讨适合河北省种植的全株玉米青贮品种.结果表明:1)青贮前玉米7377...     

Effect of Adding Reed to Diet on Growth Performance and Apparent Digestibility in Fattening Hetian Sheep

In order to investigate the growth performance and apparent digestibility of Hetian sheep in fattening period response to adding reed in diet. Seventy-five Hetian sheep with 6 months old and body weight(30.59 kg±3.36 kg) were classified into 5 groups by single-factor completely random design of experiment, fifteen sheep were assigned to 0, 10%, 20%, 30% and 40% reed addition group. Each group was fed difference diet during the experimental period (75 d). The results showed that the DM intake of 20% and 40% reed addition groups were extremely significant higher than control group (P< 0.01), respectively. The daily gain of 20% reed addition group was significantly higher than control group (P< 0.05), the daily gain of 10%, 30% and 40% reed addition groups were higher than control group 10.09%, 5.64% and 10.87% (P> 0.05), respectively. The apparent digestibility of DM, CP, EE, NDF, ADF, crude ash, calcium and phosphorus in 20% reed addition group was relatively high. Each feed unit cost and total cost would be increase when the reed content of diet increase, the reed addition groups had a better weight gains economic efficiency than control group, and the 10% reed addition group was the best. The results suggested that the DM intake, daily gain and apparent digestibility of DM, CP and EE were better when the diet adding 20% reed. Considering that feed total cost, there were a better economic benefit when the diet adding 10% reed.     

Effect of level of whole cottonseed on intake, digestibility, and performance of growing male goats fed hay-based diets

Twenty-four purebred Boer (Capra hircus hircus) and 12 male kids of 1/2 Boer breeding (initial BW 21 +/- .5 kg) were used in a randomized complete block design to study the effects of increasing level of whole cottonseed (WCS) on ADG, serum urea N, plasma gossypol, live grades, and intake of DM, CP, NDF, ADF, hemicellulose, cellulose, lignin, ether extract, and free gossypol. A subgroup of 16 purebred goats was used to determine digestibility using a 5-d total fecal collection. Goats were blocked by BW and then assigned at random to one of four diets containing 0, 8, 16, or 24% WCS. All diets contained 71% chopped orchardgrass (Dactylis glomerata L.) hay and 29% concentrate; WCS replaced corn and soybean meal to maintain calculated TDN and CP concentrations at 68 and 15% of DM, respectively. Concentrations of NDF in diet DM were 52.4, 55.9, 59.3, and 62.1% with increasing WCS, and the Ca:P ratio was maintained at 2:0. Goats were given ad libitum access to feed and water. Over the 90-d performance phase, DMI (P < .05), CP intake (P < .02), and ADG (P < .01) decreased linearly with increasing WCS in the diet, whereas ether extract (EE) intake increased in a cubic fashion (P < .01). Gain:feed decreased linearly (P < .02) with increasing level of WCS. Addition of WCS resulted in linear decreases in apparent digestibility coefficients of DM (P < .02) and NDF (P < .05), a linear increase in total plasma gossypol (P < .01), and a quadratic increase in serum urea N (P < .04). Apparent digestibility of CP was not affected by WCS level. At the 16 and 24% WCS levels, EE constituted 4.2 and 4.8% of total DMI, respectively. Adding WCS to diets for growing goats had detrimental effects on animal performance, and, based on the possible negative effects of dietary EE and NDF rather than gossypol, economics should dictate whether to use WCS in feeding programs.     

日粮中添加芦苇对育肥期和田羊生长性能及表观消化率的影响

为分析日粮中添加不同水平的芦苇对育肥期和田羊生长性能及表观消化率的影响,本研究选取75只6月龄、体重为（30.59±3.36）kg的和田羊,采用单因素完全随机试验设计,随机分为0、10%、20%、30%和40%芦苇水平,每组15只,试验期75 d。结果发现,20%和40%芦苇添加组的干物质采食量均极显著高于对照组（P< 0.01）;20%芦苇添加组的日增重显著高于对照组（P< 0.05）,10%、30%和40%芦苇添加组的日增重分别比对照组高出10.09%、5.64%和10.87%,但差异不显著（P> 0.05）;20%芦苇添加组的干物质、粗蛋白质、粗脂肪、中性洗涤纤维、酸性洗涤纤维、粗灰分、钙和磷的表观消化率均较高;各组的饲料单位成本与饲料总成本随着芦苇添加量的增加而增加,芦苇添加组的增重收益均高于对照组,10%芦苇添加组的经济效益最高。结果表明,日粮中添加20%芦苇时干物质采食量、日增重及干物质、粗蛋白质、粗脂肪的表观消化率均较好;考虑到饲料投入成本,日粮中添加10%芦苇经济效益最高。