Effect of supplementation of soy sauce oil and Ca salts of fatty acids on rumen fermentation,milk production and conjugated linoleic acid in milk of dairy cows

Eight cows were used to evaluate the effects of supplementation of soy sauce oil (SO) or Ca salts of fatty acids (FA) on rumen fermentation and milk production. The control diet (CO) consisted mainly of hay, corn silage and a concentrate. In the experimental diets, 400 g/day per cow of SO or FA (soybean oil and rapeseed oil) was supplemented to the CO diet. Experimental period for the three treatments was 14 days, and milk samples were taken during the last 2 days and rumen sample was taken on the last day. Dry matter intake was not affected by the treatments. The number of rumen protozoa at 0 h increased by SO and FA diets. Total volatile fatty acids at 2 h after feeding of SO diet was decreased compared to CO. The milk composition yield did not differ among treatments, although the percentages of fat and protein were decreased by SO and FA diets. The proportions of C8–C16 fatty acids in milk fat decreased, and those of C18 increased by SO and FA diets. The proportion of cis‐9, trans‐11 conjugated linoleic acid in milk fat by SO and FA diets increased by 120% and 135%, respectively. In spite of the slight suppression of rumen fermentation by SO diet, negative effects on feed intake and milk production were not detected.     

Effect of plant oils and aspartate on rumen fermentation in vitro

The effect of plant oils and aspartate (ASP) on rumen fermentation in vitro. The objective of this study was to determine the effect of plant oils (rapeseed - RO, sunflower - SO; linseed - LO; 10% wt/wt) and 8 mmol sodium aspartate on rumen fermentation of a diet (250 mg) consisting of hay, barley and sugar beet molasses (60 : 30 : 10). Rumen fluid was collected from two Slovak Merino sheep fed the same diet twice daily. Mixed ruminal micro-organisms were incubated in fermentation fluid (40 ml) containing rumen fluid and McDougall's buffer (1 : 4). Incubations were carried out in batch cultures for 72 h at 39 degrees C two times in a 3-week intervals. When compared to the control, all supplemented diets (RO, SO, LO, ASP) significantly increased the pH, the mol% of propionate (LO + 8.7%; SO + 10.12%; RO + 8.65%; ASP + 5.86%) and the acetate : propionate ratio and numerically decreased methane production (SO -32.8%; LO, RO -30.08%; ASP -21.56%). Lactate production was also significantly decreased. Addition of plant oils to aspartate-treated incubations partly inhibited the decrease of n-butyrate, lactate and the increase of pH and in vitro dry matter digestibility (IVDMD) caused by ASP treatment. The effect of combined additives (RO + ASP, SO + ASP, LO + ASP) on methane production SO + ASP (-19.23%) and mol% propionate SO + ASP (+2.66%), LO + ASP (+4.28%) was less effective. All combined additives caused a significant decrease in digestibility of the given feeds. No effect of plant oils and ASP could be observed on the parameters of rumen fermentation (mainly methane and propionate).     

Manipulation of rumen fermentation and ecology of swamp buffalo by coconut oil and garlic powder supplementation

This experiment was conducted to investigate the effect of coconut oil and garlic powder supplementation on digestibility of nutrients, rumen fermentation, rumen ecology, rumen microorganism and methanogen diversity. Four, 3-year old, rumen fistulated swamp buffalo bulls were randomly assigned in a 4 × 4 Latin square design to receive four dietary treatments; 7% coconut oil, 7% coconut oil with 50 g/day of garlic powder, 7% coconut oil with 100 g/day of garlic powder and non-supplemented (control). During the experiment, concentrate was offered at 0.5% of BW while rice straw was given on ad libitum basis. It was found that supplementation of 7% coconut oil had significantly influenced on total DM intake, OM, NDF and ADF digestibilites while supplementation of 7% coconut oil with garlic powder (50 and 100 g/day) were not significantly different when compared with the control. Dietary supplementations did not affect on rumen pH, NH₃–N concentrations. Blood urea nitrogen (BUN) was significantly higher in supplemented groups. Total VFA concentration, proportion of acetate and acetate to propionate ratio were reduced by supplementation. Proportion of propionate was increased (P < 0.05) when supplemented with 7% coconut oil and 7% coconut oil with 100 g/day of garlic powder. Methane production was dramatically reduced (P = 0.005) in supplemented treatments and was 10% reduced in 7% coconut oil supplementation. Amylolytic and proteolytic bacteria were increased (P = 0.007 and P = 0.024) while protozoal population decreased by 68–75% (P < 0.01) by supplementation. Total bacterial population was increased by supplementation while total fungi and total methanogens were not significantly different among treatments. Percentage of cellulolytic bacterial population was not different among treatments. However, dietary supplementation reduced (P < 0.001) percentage of F. succinogenes population. However, methanogen diversity was not changed using PCR–DGGE as technique. Thirteen separate bands were found in the DGGE gel. Based on this study, supplementation with 7% coconut oil plus 100 g/day of garlic powder could be efficiently utilized in the rumen and thus, could provide good fermentation end products and improve rumen ecology for the host swamp buffaloes particularly in reducing 9% methane gas production without changing nutrient digestibilities.     

日粮中添加不同水平红花油对绵羊瘤胃体外发酵动力学的影响

为探索红花油对瘤胃微生物发酵动力学的可能影响,试验以安装有永久性瘤胃瘘管的中国美利奴羊作为瘤胃微生物的供体动物,采用体外产气量法研究饲粮添加不同水平的红花油对绵羊瘤胃发酵动力学的影响。红花油的添加水平分别设0(对照组)、1%、2%和3%。结果表明:日粮添加2%和3%的红花油使产气速率和最大产气量明显低于对照组(P<0.05)。不同水平的红花油并未显著改变发酵液pH值、NH3-N浓度、CMCase及XYLase活性(P>0.05)。3%组的DM降解率略低于对照组(P<0.05),但与其他2个处理组差异不显著(P>0.05)。各处理组的NDF降解率较对照组也略有降低(P<0.05)。总挥发酸(TVFA)浓度、乙酸、丙酸摩尔百分比和乙丙酸比等指标各组间均差异不显著(P>0.05)。综上所述,饲粮中添加不超过3%水平的红花油对绵羊瘤胃发酵动力学没有负面影响。     

富含十八碳不饱和脂肪酸的植物油对体外瘤胃发酵和甲烷生成的影响

选取3种典型的植物油:菜籽油、豆油和亚麻油,利用体外培养系统进行体外发酵,研究植物油的类型和添加水平对瘤胃体外发酵和甲烷生成的影响。3种植物油分别添加底物干物质的3%、5%和7%,未添加植物油组为对照,共10个处理,每个处理设3个重复。结果表明,菜籽油对甲烷产量无显著影响(P>0.05),豆油7%添加水平显著抑制了甲烷生成,而亚麻油所有添加水平均显著降低了甲烷生成量(P<0.05)。在豆油和亚麻油处理组中,随着添加水平的提高,甲烷产量线性下降(P<0.01)。3种植物油均显著改变了瘤胃发酵模式,随着植物油中所含不饱和脂肪酸不饱和度的增加,乙酸和丁酸的摩尔比例显著降低,丙酸摩尔比例显著升高(P<0.05);植物油添加水平的提高显著降低了乙酸和丁酸摩尔比例,显著升高了丙酸摩尔比例(P<0.05),乙酸丙酸比例显著降低。本试验结果表明植物油降低甲烷的效果跟其来源和添加水平有关;随着植物油添加水平的提高和所含不饱和脂肪酸不饱和度的增加,甲烷生成量显著降低。     

Reducing methane production by supplementation of Terminalia chebula RETZ. containing tannins and saponins

This study investigates the effects of Terminalia chebula Retz. meal supplementation on rumen fermentation and methane (CH₄) production by using an in vitro gas technique. The experimental design was a completely randomized design (CRD) and the dietary treatments were T. chebula supplementation at 0, 4, 8, 12, 16 and 20 mg with 0.5 g of roughage and concentrate ratio at 60:40. The results revealed that cumulative gas production (96 h of incubation) were higher (P < 0.01) with T. chebula supplementation at 12, 16 and 20 mg than other treatments. However, in vitro dry matter degradability (IVDMD) and in vitro organic matter digestibility (IVOMD) were not significantly different among treatments (P > 0.05). The NH₃‐N concentrations tended to quadratically increase with increasing levels of T. chebula in the diet. In addition, total volatile fatty acids (VFA) and propionate concentrations were increased (P < 0.01), while acetate concentration, acetate‐to‐propionate ratio, CH₄ production and protozoal populations were decreased (P < 0.01) when supplemented with T. chebula at 8, 12 and 16 mg, respectively. Based on this study, it could be concluded that supplementation of T. chebula at 12 mg could improve rumen fermentation by reducing CH₄ production and protozoa populations, thus improving in vitro gas production and VFA profiles.     

Effect of dietary choline on volatile fatty acids in rumen liquid of sheep and rumen dry matter degradability of untreated and ammonia-treated wheat straw

Three rumen fistulated wethers consumed a roughage (1200 g artificially dried grass) or a concentrate/roughage diet (600 g concentrate, 400 g dried grass per animal and day). The diets were unsupplemented or 0.5, 1 or 2 g choline per animal and day were added. After a 14-day feeding period, samples of rumen liquid were taken 0, 1, 2, 3, 4 and 6 h after morning feeding. In a second experiment, untreated and ammonia-treated wheat straw were incubated in nylon bags for 6, 12, 24, 48 and 72 h in rumen of 5 sheep fed on 1.2 kg dried grass and without or with 1 g choline per day. Choline supplementation decreased the total concentration of volatile fatty acids in rumen liquid in both types of diet (roughage: 106, 83, 89 and 87; concentrate/roughage: 142, 114, 91 and 106 mmol/l for 0, 0.5, 1 and 2 g choline per day resp.). Concentration of acetate and branched chain fatty acids in both diets and butyrate in concentrate/roughage diet was reduced as total acids. Butyrate in roughage diet was increased by added choline. Molar propionate concentration was not significantly influenced by choline (P greater than 0.05). Choline resulted in a little increase (P greater than 0.05) of dry matter degradability in rumen, especially when NH3-treated straw was incubated. The effect of choline on milk fat production of cows fed with diets rich in concentrate is probably not related to changes in rumen fermentation and digestion.     

Effect of Tween 80 and monensin on ruminal fermentation of the diet containing 70% wheat straw treated by white-rot fungus in artificial rumen

The objective of this study was to investigate the effect of Tween 80 and monensin on rumen fermentation of the diet containing 70% wheat straw treated by white-rot fungus Pleurotus tuber-regium (TWS-PT) and 30% barley in artificial rumen (RUSITEC). The RUSITEC consisted of four fermentation vessels (V1, V2, V3, V4): V1 was without additives (control), V2 received daily 10 mg of monensin, V3 received daily 0.5% Tween 80 (vol.wt-1) and V4 involved the combination of 10 mg of monensin with 0.5% Tween 80 (vol.wt-1). After an adaptation period (6 days) the fermentation parameters were determined for six consecutive days. Tween 80 did not affect the rumen fermentation of the diet consisting 70% TWS-PT and 30% barley in RUSITEC. Monensin affected the rumen fermentation of the diet by the decreased degradability of DM, neutral detergent fiber (NDF), acid detergent fiber (ADF), hemicellulose, cellulose (p < 0.001), the decrease of methane production (p < 0.001) and the higher proportion of propionate within the volatile fatty acids (p < 0.001) in comparison to control. Tween 80 did not improve the potency of monensin. Only some indices of the increase mol% of propionate (about 3.4%) and the decrease of methane production (about 0.47 mmol.day-1) were found by using Tween 80 plus monensin in comparison to use of monensin alone.     

饲粮中添加海南霉素对奶牛瘤胃发酵及甲烷产量的影响

本试验旨在研究海南霉素对荷斯坦奶牛瘤胃发酵模式及甲烷产量的影响。试验选用3头装有永久性瘤胃瘘管、体况相近的中国荷斯坦奶牛,采用3×3拉丁方试验设计,试验分为3期,每期15 d,试验设负对照组(不添加任何添加剂)、正对照组(添加10 mg/kg莫能菌素)和海南霉素组(添加7.2 mg/kg海南霉素)。结果表明:饲粮中添加海南霉素后,除在采食后2 h显著提高奶牛瘤胃内pH(P<0.05)外,其他时间均无显著影响(P>0.05);采食后0、2、8和10 h,海南霉素组氨态氮(NH3-N)浓度均显著低于负对照组(P<0.05),而采食后6 h,海南霉素有抑制NH3-N释放的趋势(P=0.06);采食后0、2、4和6 h,海南霉素组乙酸浓度及乙酸与丙酸的比值与负对照组相比均显著降低(P<0.05),丙酸浓度显著升高(P<0.05),总挥发性脂肪酸和丁酸浓度没有显著变化(P>0.05)。海南霉素显著抑制了瘤胃甲烷的产生(P=0.02),海南霉素组的奶牛甲烷呼出量为216.50 L/d,比负对照组降低了14.03%。由此得出结论:饲粮中添加海南霉素可以改变奶牛瘤胃的发酵类型,使其更趋向于丙酸型发酵,并显著降低动物的甲烷呼出量。     

Incorporation of soya oil hydrolysate in the diet of defaunated or refaunated sheep: effect on rumen fermentation in vitro

The effects of incorporation in the diet of 7% soya oil hydrolysate (SOH) on in vitro incubations of cellobiose + maltose, maize starch and casein by rumen microbes were studied using defaunated and refaunated sheep as rumen fluid donors. Feeding refaunated sheep the SOH supplemented diet lowered the protozoal numbers in the rumen from 1.61 10(6)/ml to 6.1 10(5)/ml. SOH addition reduced in vitro methane production, rather by a depletion of methanogens is than by a simple inhibition of their activity. This reduction seemed to be independent of protozoa depletion. With cellobiose-maltose and maize starch incubations, SOH supplementation increased molar proportion of propionate while acetate decreased. Both variations could be linked to the inhibition of methanogenesis. Volatile fatty acid production from casein was strongly reduced by SOH supplementation with or without protozoa in the rumen of the donors animals.     

Effect of diets containing linoleic acid- or oleic acid-rich oils on ruminal fermentation and nutrient digestibility, and performance and fatty acid composition of adipose and muscle tissues of finishing cattle

Two trials were conducted to determine the effect of linoleic acid- or oleic acid-rich safflower oil on ruminal fermentation, nutrient digestion, feedlot performance, carcass characteristics, and fatty acid composition of adipose and muscle tissues of beef cattle. In both trials, cattle were fed a finishing diet based on barley grain, wheat silage, and alfalfa hay. Oils were fed at 5% of dietary DM. In a metabolism trial, four ruminally and duodenally cannulated Angus crossbred steers were subjected to linoleic acid-rich oil or oleic acid-rich oil in a crossover design with covariate periods (no oil supplementation). In a finishing trial, 16 individually fed Angus crossbred steers and heifers (eight per diet) received linoleic acid- or oleic acid-rich oils during the last 86 d of a 116-d feeding period. Ruminal pH, ammonia concentration, protozoal counts, major VFA concentrations, acetate-to-propionate ratio, polysaccharide-degrading activities, microbial N flow to the duodenum, and the efficiency of microbial N synthesis in the rumen were not affected (P = 0.18 to 0.96) by type of oil. Type of oil had no effect on total-tract apparent digestion of nutrients (P = 0.46 to 0.98). Ruminal true nutrient digestibilities did not differ between oils (P = 0.15 to 0.99), except that the linoleic acid-rich oil decreased (P = 0.05) NDF digestibility. Dry matter intake, ADG, G:F, and carcass characteristics did not differ (P = 0.11 to 0.84) between the two oils. Overall, the difference in dietary fatty acids provided to the cattle produced few changes in tissue fatty acids. Weight percentages of c9t11 CLA were unaltered by the addition of linoleic acid to the diet compared with oleic acid, probably as a result of low vaccenic acid production in the rumen, as the pathway of biohydrogenation was apparently primarily through the t10 pathway.     

Theoretical turnover rate of the rumen liquid fraction in dairy cows and its relationship to feed intake,rumen fermentation,and milk production

Ruminant animals are able to convert plant materials (grain and the human‐indigestible portion of carbohydrates) to milk and meat. In this conversion, most of the plant materials are digested by rumen fermentation and are changed to short‐chain fatty acids, microbial cells, and methane, which is released into the atmosphere. The relationships among feed, rumen fermentation, and milk production are poorly understood. Here we report a novel indicator of characteristics of rumen fermentation, theoretical turnover rate (TTOR) of the rumen liquid fraction. The TTOR was calculated from the presumed rumen volume (PRV) which is estimated by dividing the methane yield by the methane concentration of rumen fluid. The formula for the TTOR is: TTOR = PRV/body weight^0.75. Our present analyses confirm that the TTOR as an indicator is capable of connecting feed, rumen fermentation, and milk production, because dry matter intake/TTOR showed a strong correlation with milk yield/TTOR. In addition, the TTOR may be related to ruminal pH, as we observed that the ruminal pH decreased as the TTOR increased. We propose that the TTOR is a factor characterizing rumen fermentation and a good indicator of the productivity of ruminants and dysbiosis of the rumen microbiome.     

In vitro gas production in rumen fluid of buffalo as affected by urea‐calcium mixture in high‐quality feed block

This study aimed to determine the effect of urea‐calcium sulphate mixture (U‐cas) levels in high‐quality feed block (HQFB) on ruminal digestibility, fermentation and gas kinetics in rumen fluid of swamp buffalo by using in vitro techniques. The treatments were seven levels of U‐cas incorporated in HQFB at 0, 3, 6, 9, 12, 15 and 18% and the experimental design was a completely randomized design. Gas production rate constants for the insoluble fraction, potential extent of gas and cumulative gas were linearly increased with increasing levels of U‐cas in HQFB. The in vitro dry matter digestibility, in vitro organic matter digestibility, true digestibility and microbial mass were altered by treatments and were greatest at 18% U‐cas supplementation. Concentrations of propionate were linearly increased with increasing levels of U‐cas and was highest with U‐cas supplementation at 18%. The NH₃–N concentration was highest when urea was added in the HQFB while NH₃–N concentration tended to be reduced with increasing level of U‐cas. The findings suggest supplementation of 18% U‐cas in HQFB improves kinetics of gas production, rumen fermentation, digestibility and microbial mass as well as controlling the rate of N degradation in the rumen of swamp buffalo.     

利用体外产气法研究不同瘤胃降解蛋白平衡对瘤胃代谢的影响

旨在探讨利用体外产气法研究不同瘤胃降解蛋白平衡日粮(RDPB,g·kg-1 DM)对瘤胃发酵、总产气量和甲烷产量的影响.试验选用美国Ankom产气系统,采用随机区组试验设计,配置6种不同瘤胃降解蛋白平衡日粮,分别为日粮1(-20 g· kg-1 DM),日粮2(-10 g· kg-1 DM),日粮3(0 g· kg-1 DM),日粮4(10g·kg-1DM),日粮5(20 g·kg-1 DM)和日粮6(30 g· kg-1 DM),每组2个重复,培养期为24 h.结果表明:(1)本研究中6种类型日粮发酵液的pH、乙酸/丙酸、产气量和CH4产生量表现为日粮3(P＜0.01)或日粮4(P＜0.01)值最低.(2)挥发性脂防酸乙酸、丙酸、丁酸以及氨氮的浓度随着瘤冒降解平衡值的增加而增加,表明改变日粮瘤胃降解蛋白平衡可以影响瘤胃发酵.而瘤胃降解蛋白平衡对总挥发性脂肪酸以及原虫数量无显著影响.(3)日粮瘤胃降解蛋白平衡值影响不同时间点甲烷的浓度和24 h甲烷产量.其中以日稂4(P＜0.05)甲烷总产量最低.由此可见,在体外培养条件下,改变日粮RDPB影响了瘤胃发酵液pH、氨态氮(NH3-N)及挥发性脂肪酸(VFA)浓度、总产气量、CH4产生量,综合考虑其对瘤胃发酵和甲烷产量等指标的影响,体外产气条件下适宜的RDPB水平为0～10g·kg-1 DM.     

Dependence of rumen fatty acid production on the composition of rations

In three experiments with two Black-and-White dairy cows the influence of soybean oil and coconut fat as well as that of rations rich in roughage and concentrated feed on the production of fatty acids were determined with the isotope dilution method. A change in the method of sampling from the rumen in the course of the investigations resulted in distinctly different absolute production quotas, which can presumably be traced back to the disproportionate mixing in of the isotope and/or different production quotas in various regions of the rumen. The relative differences between the production quotas dependent on the rations, however were approximately the same with both sampling methods, so that they make the comparison of the rations concerning rumen fermentation possible. The production of acetic acid and the total production of fatty acids (C2--C4) correlated closely both with the intake of digestible energy and the intake of digestible organic matter. There was also a highly significant correlation o that they make the comparison of the rations concerning rumen fermentation possible. The production of acetic acid and the total production of fatty acids (C2--C4) correlated closely both with the intake of digestible energy and the intake of digestible organic matter. There was also a highly significant correlation o that they make the comparison of the rations concerning rumen fermentation possible. The production of acetic acid and the total production of fatty acids (C2--C4) correlated closely both with the intake of digestible energy and the intake of digestible organic matter. There was also a highly significant correlation between the relation of acetic and propionic acid in the rumen fluid and the quotient from acetic and propionic acid produced. In contrast to this, a significant relation between the concentration of fatty acids and the production of fatty acids could not be ascertained. Soybean oil and coconut fat brought about a slightly better utilisation of the fat-free organic matter for the production of fatty acids in the rumen. This could mainly be traced back to the increased production of propionic acid. The production of acetic acid per kg fat-free organic matter was insignificantly reduced. A reduced quota of roughage in the ration as well as the use of feed fats resulted in a decrease in the production of acetic acid and an increase in the production of propionic acid. The influence of the quota of roughage, however, was bigger than that of the use of fats. When rations rich in roughage were given, the share the energy contained in the total fatty acids has in the total of the digested energy was, on an average of both animals, slightly lower in comparison to rations rich in concentrated feed. However, the reason for this is not to be found in a lower share the energy digested in the stomachs has in the total of digested energy but in a higher amount of fermentation losses with a nutrition rich in roughage.     

Influence of plant lecithin partly replacing rumen-protected fat on digestion, metabolic traits and performance of dairy cows

Nutrient digestibility, metabolic effects and performance were evaluated in lactating cows (n = 6 × 6) receiving diets containing one of four different lecithins (raw, deoiled and deoiled/partially hydrolysed soy lecithin, raw canola lecithin) or soybean oil in combination with Ca soaps of palm oil fatty acids in a ratio of 1 : 3. A diet supplemented only with Ca soaps served as a control. The complete diets consisted of forage and concentrate (0.62 : 0.38) and total lipid supplementation was 30 g fatty acids/kg dietary dry matter. Lecithins had no effect on milk yield and milk composition. Apparent digestibility of dry matter, organic matter and gross energy were highest in the control diet and lowest in the soybean oil diet (p < 0.1) with intermediate values for the lecithin‐supplemented diets. Soybean oil particularly reduced fibre digestibility (significant with hemicellulose), whereas this effect was reduced or even missing when lecithins, particularly raw canola lecithin and deoiled/hydrolysed soy lecithin, were used. The digestibility of total fatty acids was not affected by the treatments. The effects were also not significant for blood plasma traits except for insulin which was significantly higher with raw than with deoiled/hydrolysed soy lecithin. In conclusion, lecithins, particularly those technologically modified or of a low polyenoic fatty acid content, might be preferred to oils when used as an energy source whereas they failed to improve digestibility of rumen‐protected fats.     

Effects of defaunation and dietary coconut oil distillate on fermentation,digesta kinetics and methane production of Brahman heifers

A 2 × 2 factorial experiment was conducted to assess the effects of presence or absence of rumen protozoa and of dietary coconut oil distillate (COD) supplementation on rumen fermentation characteristics, digesta kinetics and methane production in Brahman heifers. Twelve Brahman heifers were selected to defaunate, with 6 being subsequently refaunated. After defaunation and refaunation, heifers were randomly allocated to COD supplement or no supplement treatments while fed an oaten chaff‐based diet. Methane production (MP; 94.17 v 104.72 g CH₄/d) and methane yield [MY; 19.45 v 21.64 g CH₄/kg dry matter intake (DMI)] were reduced in defaunated heifers compared with refaunated heifers when measured at 5 weeks after refaunation treatment (p < 0.01). Supplement of COD similarly reduced MP and MY (89.36 v 109.53 g/d and 18.46 v 22.63 g/kg DMI, respectively; p < 0.01), and there were no significant interactions of defaunation and COD effects on rumen fermentation or methane emissions. Concentration of total volatile fatty acid (VFA) and molar proportions of acetate, propionate and butyrate was not affected by defaunation or by COD. Microbial crude protein (MCP; g/d) outflow was increased by defaunation (p < 0.01) in the absence of COD but was unaffected by defaunation in COD‐supplemented heifers. There was a tendency towards a greater average daily gain (ADG) in defaunated heifers (p = 0.09), but COD did not increase ADG (p > 0.05). The results confirmed that defaunation and COD independently reduced enteric MP even though the reduced emissions were achieved without altering rumen fermentation VFA levels or gut digesta kinetics.     

饲喂不同油脂对黄羽肉鸡肌肉组织中脂肪酸组成的影响

选用 8 3日龄的雌性广西黄羽肉鸡 90只 ,随机分成 5组 (每组设 2个重复 ,每个重复 9只 ,共 18只 ) ,研究饲粮中不同油脂对肉鸡肌肉组织脂肪酸组成的影响。 5组饲粮分别含 3%的富含饱和脂肪酸的棕榈油 (PO3组 ,对照组 )、 3% (LO3组 )和 5%的富含α 亚麻酸 (C18:3n 3,ALA)的亚麻油 (LO5组 )、 5%的富含长链n 3脂肪酸 (如C2 0 :5n 3,EPA ;C2 2 :6n 3,DHA)的鱼油 (FO5组 )、 5%的富含亚油酸(C18:2n 6 ,LA)和ALA的火麻仁油 (HO5组 )。饲喂 2 8d,取样测定胸肌和腿肌中的脂肪酸组成。结果表明 :PO3(对照组 )肌肉中的n 6 /n 3脂肪酸比值比例高于其他组 (P <0 0 5) ;与对照组相比 ,LO3组和LO5组以ALA和LA为主的多不饱和脂肪酸 (PUFA)增加 (P <0 0 5) ,ALA和LA在体内可转化为相应的长链脂肪酸 ;FO5组以长链n 3PUFA ,(如EPA、DPA、DHA)为主的PUFA含量增加 (P <0 0 5) ;HO5组以LA为主的n 6脂肪酸高于其他组 (P <0 0 5) ;长链PUFA (如DHA)易沉积于胸肌中 ,而LA ,ALA易沉积于腿肌中。由此可见 ,肉鸡肌肉组织脂肪酸的组成充分反映了饲粮油脂的脂肪酸组成 ,通过饲粮中添加不同脂肪酸组成的油脂可生产富含特定PUFA的鸡肉     

葡萄籽精油对体外瘤胃发酵和甲烷生成的影响

通过体外培养法研究发酵底物精粗比7∶3条件下,添加100,150和250μL/L葡萄籽精油对瘤胃发酵和甲烷产量的影响。采用气相色谱仪测定甲烷产量,培养24 h后,测定挥发性脂肪酸、pH、氨态氮浓度和原虫数。结果发现,添加葡萄籽精油100μL/L和150μL/L与对照组相比提高累计产气量、发酵液pH值(P<0.05)、乙酸摩尔比例,降低甲烷浓度(P<0.01)、丙酸、丁酸、戊酸和支链挥发性脂肪酸摩尔比例。葡萄籽精油添加量为150μL/L降低氨态氮浓度及瘤胃原虫数,添加100μL/L葡萄籽精油提高总挥发性脂肪酸。试验表明,适宜添加量的葡萄籽精油可以改变瘤胃发酵模式,增加丙酸乙酸比例,抑制甲烷生成。     

Influence of Carotino oil on in vitro rumen fermentation,metabolism and apparent biohydrogenation of fatty acids

The study appraised the effects of Carotino oil on in vitro rumen fermentation, gas production, metabolism and apparent biohydrogenation of oleic, linoleic and linolenic acids. Carotino oil was added to a basal diet (50% concentrate and 50% oil palm frond) at the rate of 0, 2, 4, 6 and 8% dry matter of the diet. Rumen inoculum was obtained from three fistulated Boer bucks and incubated with 200 mg of each treatment for 24 h at 39°C. Gas production, fermentation kinetics, in vitro organic matter digestibility (IVOMD), volatile fatty acids (VFA), in vitro dry matter digestibility (IVDMD), metabolizable energy and free fatty acids were determined. Carotino oil did not affect (P > 0.05) gas production, metabolizable energy, pH, IVOMD, IVDMD, methane, total and individual VFAs. However, Carotino oil decreased (P < 0.05) the biohydrogenation of linoleic and linolenic acids but enhanced (P < 0.05) the biohydrogenation of oleic acid. After 24 h incubation, the concentrations of stearic, palmitic, pentadecanoic, myristic, myristoleic and lauric acids decreased (P < 0.05) while the concentration of linolenic, linoleic, oleic and transvaccenic acids and conjugated linoleic acid (CLAc9t11) increased (P < 0.05) with increasing levels of Carotino oil. Carotino oil seems to enhance the accumulation of beneficial unsaturated fatty acids without disrupting rumen fermentation.