Proportion Of Acetic Acid Research Articles

EFFECTS OF HIGH AMBIENT TEMPERATURE IN RABBITS : METABOLIC CHANGES, CAECAL FERMENTATION AND BACTERIAL FLORA.

Eighteen male New Zealand White rabbits, randomly assigned to three groups, were placed in a climatic chamber at 20 oC. After 10 days of adaptation the temperature was risen every day to 30oC from 08:00 a.m. to 08:00 p.m. The three groups of animals were slaughtered according to the following schedule: six animals at the end of adaptation period (control), six animals 2 days after the beginning of the heat stress, and six animals 14 days after the beginning of the heat stress. At the same schedule blood samples were collected through the ear vein. The exposure to hot environment induced a net decrease of feed consumption in the first two days that was partially recovered in the following days. No relevant changes were observed for plasma metabolic parameters concentration in the different sampling times, except for an increase of total proteins on day 2, and a tendency to decrease for glucose on day 2 and 14 (P<0.08). Total volatile fatty acids concentration in the caecal content significantly decreased on day 2 and 14 and a parallel trend was observed for acetic, propionic and butyric acid concentration. No relevant changes were observed in the molar proportion of acetic, propionic and butyric acid and pH. Ammonia concentration of the caecal content decreased on day 2. Total anaerobes significantly increased on day 2, clostridia significantly increased on day 2 and 14. No significant changes were recorded for lactobacilli and total coliforms.

The effect of feeding essential oils on broiler performance and gut microbiota

1. In this study the effect of a blend of essential oils (EO) comprising 15 g/tonne thymol and 5 g/tonne cinnamaldehyde on the performance and intestinal microbiota of broilers was investigated. 2. A total of 720 male Ross broilers were divided into two dietary treatments with 12 replicate pens per treatment. Broilers were given a control soybean-wheat-based diet with or without added EO in two diet phases (0–21 d and 22–42 d). 3. The blend of EO increased body weight gain of broilers from 0 to 42 d by 4⋅5%. 4. Caecal microbiota were affected by the EO blend; in particular increases in the proportions of Lactobacillus and Escherichia coli at 41 d was observed. 5. The EO blend had major effects on caecal metabolites. The proportion of caecal butyrate at 20 and 41 d of age increased, whereas the proportion of caecal acetic acid at 20 d, and propionic acid and isovaleric acid at 41 d, decreased with the EO blend. In addition, the caecal proportion of spermine increased and tyramine decreased at 41 d of age with the EO treatment. 6. The present study shows that EO supplementation exerts a positive effect on intestinal microbiota with a concomitant enhancement in growth performance. The study suggests that modulation of broiler gut microbiota composition and activity through the administration of EO offers an effective means for improving broiler performance.

Effect of Additive on the Chemical Composition of Tra Catfish (Pangasius hypophthalmus) By-product Silages and Their Nutritive Value for Pigs

Two experiments were conducted to determine i) the fermentation characteristics of catfish by-product (C) ensiled with rice bran (RB) or sugarcane molasses (M) in different ratios, and ii) the digestibility of the silages in growing pigs. In the ensiling experiment, there were three ratios of C, ensiled with RB or M, of 8:2, 7:3 and 6:4 (wet basis for C and air-dry basis for RB and M). The six treatments were CRB8:2, CRB7:3, CRB6:4, CM8:2, CM7:3 and CM6:4, with 3 replications per treatment and seven sampling times. The pH of CRB7:3 and CRB6:4 decreased (p<0.05) from the first week and stayed stable until 8 weeks of ensiling, but the pH did not decrease in CRB8:2. The pH of CM8:2, CM7:3 and CM6:4 decreased rapidly from the first week until week 8. Dry matter (DM) and crude protein (CP) contents were slightly lower when catfish by-product was ensiled with RB than with M. Ammonia content in all treatments increased (p<0.05) during ensiling. Lactic acid content in silages with molasses increased from the first week, with the highest value at week 4. However, the lactic acid content in CRB8:2 did not increase with time and had the lowest value of all treatments. Acetic acid proportions of total volatile fatty acids were low at day 0, with the highest value at day 7, decreasing slowly until 8 weeks. The butyric acid proportion was highest at day 0 and decreased up to week 8. The proportion of propionic acid increased during ensiling. The digestibility experiment had a 4x4 Latin-square design and included 4 castrated crossbreed (Yorkshire×Landrace) male pigs fed four diets. The basal diet (BD) included rice bran, broken rice and maize meal, and the other three diets included fish meal (FMD) or catfish by-product ensiled with rice bran (CRBD) or sugarcane molasses (CMD). The silages chosen were those which gave the best results in the ensiling experiment for each additive. The coefficient of total tract apparent digestibility (CTTAD) of DM and organic matter (OM) was not significantly different among treatments. The CTTAD of CP was not different among the silage diets, but was lower in BD (p<0.01). The CTTAD of ether extract (EE) was higher in the catfish by-product silage diets than in FMD and BD. There was no significant difference in the digestibility of DM, OM, CP and EE between the fish meal and the by-product silages. In conclusion, catfish by-product can be successfully preserved by ensiling. Moreover, the total tract apparent digestibility of OM, CP and EE in ensiled catfish by-product was comparable with that of fish meal.

Methane emissions, feed intake, performance, digestibility, and rumen fermentation of finishing beef cattle offered whole-crop wheat silages differing in grain content1

This study aimed to quantify the methane emissions and feed intake, performance, carcass traits, digestibility, and rumen fermentation characteristics of finishing beef cattle offered diets based on whole-crop wheat (WCW) silages differing in grain content and to rank these relative to diets based on grass silage (GS) and ad libitum concentrates (ALC). In Exp. 1, a total of 90 continental crossbred steers [538 +/- 27.6 kg of BW (mean +/- SD)] were blocked by BW and assigned in a randomized complete block design to 1 of 6 treatments based on 4 WCW silages [grain-to-straw plus chaff ratios of 11:89 (WCW I), 21:79 (WCW II), 31:69 (WCW III), and 47:53 (WCW IV)], GS, and ALC. Increasing grain content in WCW silage resulted in a quadratic (P = 0.01) response in DMI, with a linear (P < 0.001) increase in carcass gain [CG; 577 (WCW I), 650 (WCW II), 765 (WCW III), and 757 g/d (WCW IV)]. The G:F also increased linearly (P < 0.001) in response to increasing the grain content of WCW silage. A quadratic (P < 0.01) response in daily methane output [295 (WCW I), 315 (WCW II), 322 (WCW III), and 273 g/d (WCW IV)], measured using the sulfur hexafluoride tracer technique, was observed in response to increasing the grain content of WCW; however, linear decreases were observed when expressed relative to DMI (P = 0.01) and CG (P < 0.001). Cattle offered GS exhibited carcass gains similar to those offered WCW silage diets and had greater methane emissions than cattle in any other treatment when expressed relative to DMI. Cattle offered ALC exhibited greater (P < 0.01) carcass gains and decreased (P < 0.001) methane emissions, irrespective of the unit of expression, compared with cattle in any of the silage-based treatments. In Exp. 2, rumen fermentation parameters were determined using 4 ruminally cannulated Rotbunde-Holstein steers (413 +/- 30.1 kg of BW) randomly allocated among WCW I, the average of WCW II and III (WCW II/III), WCW IV, and GS in a 4 x 4 Latin square design. Ruminal pH and total VFA concentration did not differ across dietary treatments. Molar proportion of acetic acid decreased (P = 0.01), with propionic acid tending to increase (P = 0.06) with increasing grain content. It was concluded that increasing the grain content of WCW silage reduced methane emissions relative to DMI and CG and improved animal performance. However, the relativity of GS to WCW in terms of methane emissions was dependent on the unit of expression used. Cattle offered ALC exhibited decreased methane emissions and greater performance than those offered any of the silage-based treatments.

Effects of Volatile Fatty Acids on IGF-I, IGFBP-3, GH, Insulin and Glucagon in Plasma, and IGF-I and IGFBP-3 in Different Tissues of Growing Sheep Nourished by Total Intragastric Infusions

Twelve SuffolkxSmall-tail-Han male sheep (body weight 21-26 kg), aged four months, were used to study the effects of volatile fatty acids (VFA) on IGF-I (insulin-like growth factor-I), IGFBP-3 (insulin-like growth factor binding protein-3), GH (growth hormone), insulin and glucagon in plasma, and IGF-I and IGFBP-3 in different tissues. The sheep were randomly divided into four groups with 3 sheep in each group. The sheep were sustained by total intragastric infusions and four levels of mixed VFA (the molar proportion of acetic acid, propionic acid and butyric acid was 65:25:10), which supplied 333, 378, 423 and 468 KJ energy/kg W 0.75 /d, were infused into the rumen as experimental Treatments I, II, III and IV, respectively. The experiment lasted 12 days, of which the first 8 days were for pretreatment and the last 4 days for collection of samples. At the end of the experiment, blood samples were taken and then the sheep were slaughtered and tissue samples from the rumen ventral sac, rumen dorsal sac, liver, duodenum and Longissimus dorsi muscle were obtained. IGF-I, IGFBP-3, GH, insulin and glucagon in plasma and IGF-I and IGFBP-3 in different tissues were analysed. Results showed that the concentration of IGF-I, IGFBP-3, GH, insulin or glucagon in plasma and the content of IGF-I and IGFBP-3 in the rumen dorsal sac, rumen ventral sac, liver or Longissimus dorsi muscle were increased with VFA infusion level (p 0.05). It was concluded that IGF-I, IGFBP-3, GH, insulin and glucagon in plasma and IGF-I and IGFBP-3 in rumen dorsal sac, rumen ventral sac, liver and Longissimus dorsi muscle were increased significantly with increasing level of ruminal infusion of mixed VFA.

Effects of feeding fresh citrus pulp to Merino wethers on wool growth and animal performance

Two studies were conducted to determine the effects of replacing lupins with fresh citrus pulp in Merino wethers diets: (i) an in vitro study, which measured ruminal fermentation; and (ii) an in vivo study in which 18 mature Merino wethers were fed dietary treatments (n = 3) over 56 days to evaluate effects on performance [i.e. DM intake, average daily gain and wool growth]. In both the in vitro and in vivo studies, the control treatment consisted (in diet DM) of lucerne chaff (69.9%), lupins (30.1%) and phosphate (0.3%), whereas the citrus pulp treatments (n = 2; replacing lupins on 20 and 30% DM basis, respectively) consisted of lucerne chaff (61.7 and 63.3%), lupins (18.5 and 6.3%), phosphate (0.34 and 0.33%) and fresh citrus pulp (19.5 and 30.1%). Data were analysed using the MIXED model of SAS and orthogonal polynomial contrasts were used to determine linear (L) and quadratic responses to the level of citrus pulp. In the in vitro study, gas production, net total volatile fatty acid production as well as in vitro DM digestibility were similar (P &gt; 0.05) among the dietary treatments. Ammonia production in citrus pulp treatments were twofold lower compared with the control (L, P &lt; 0.01). The addition of citrus pulp to the diet increased the molar proportions of acetic acid and decreased that of butyric, branched-chain volatile fatty acids, and valeric acids (all L, P &lt; 0.01) compared with the control diet. In the in vivo study, DM intake, average daily gain and feed conversion were similar among treatments (P &gt; 0.52). Wool production parameters including clean fleece weight, yield and staple length were not different between diets (P &gt; 0.30). Hence, fresh citrus pulp can be included up to 30% on a DM basis replacing lupins without detrimental effects on wool production and animal performance.

Rumen fermentation characteristics in pre-weaning calves receiving yeast culture supplements

In an experiment with 45 neonatal male Holstein calves, effects of yeast cultures Yea-Sacc&lt;sup&gt;®&lt;/sup&gt; 1026 (SC) containing &lt;I&gt;Saccharomyces cerevisiae&lt;/I&gt; (strain 1026) and Vitex (KF) containing &lt;I&gt;Kluyveromyces fragilis&lt;/I&gt; (strain Jürgensen) on rumen fermentation characteristics were determined. From day 4 to day 56 of age, the calves were allocated to one of the three dietary treatments (Control, SC, and KF) of 15 animals each, placed in individual pens, and fed 4 l of whole milk twice daily and a basal concentrate mixture ad libitum as calf starter feeds. The control treatment was not supplemented with yeast culture. The yeast culture supplements Yea-Sacc&lt;sup&gt;®&lt;/sup&gt; 1026 and Vitex were top-dressed at 10 g/calf daily on the basal concentrate mixture of treatments SC and KF, respectively. At the end of the experiment (day 56), all calves were slaughtered and the rumen fluid was analysed. The administration of yeast cultures Yea-Sacc&lt;sup&gt;®&lt;/sup&gt;026 and Vitex to calves did not affect final body weight (BW), BW gain, dry matter intake, feed conversion ratio, ruminal pH, lactic acid concentration and the molar proportion of propionic acid, but it decreased (&lt;I&gt;P&lt;/I&gt; &lt; 0.05) the total volatile fatty acid concentration and the molar proportion of butyric acid, and increased (&lt;I&gt;P&lt;/I&gt; &lt; 0.05) the molar proportion of acetic acid and the acetate to propionate ratio. In addition, the microbial cellulolytic activity was higher in calves that received both yeast cultures compared to the control treatment. The results of this study suggest that the ruminal fermentation was more stable in calves receiving yeast culture supplements.

Effect of stage of growth and silage additives on whole crop cereal silage nutritive and fermentation characteristics

The efficient production and subsequent utilisation of home-grown forage is seen as the cornerstone of profitability of the dairy industry as it leads to lower unit costs of milk production compared with purchased forage or grain supplements. Cereals such as wheat (Triticum aestivum L.), oats (Avena sativa L.) and triticale (Triticum × Triticosecale) all have the potential to produce high forage dry matter (DM) yields. These forages are not widely grown within dryland Australian dairy systems and there is a paucity of information on both the agronomic requirements and subsequent ensiling and feed-out management under these conditions. The experiment reported in this paper examines the DM yield, nutritive and ensiling characteristics of three small-grain cereals (triticale, wheat and oats) cut at various stages of development and ensiled with or without silage additives. We hypothesised that: (1) delaying harvesting until later stages of growth would result in higher DM yields, but negatively impact on both nutritive and fermentation characteristics of subsequent silages; (2) ensiling wilted material at earlier harvests would improve fermentation characteristics compared with direct ensiled material; and (3) the use of silage additives at all harvests would improve fermentation characteristics of resultant silages compared with untreated silages. Apart from winter oats, the estimated metabolisable energy of forages was highest at the boot stage of growth, declined during anthesis and then rose again during milk and soft-dough stage of growth. The crude protein content of forages declined with maturity, with final values at soft dough below 90 g/kg DM. Neutral detergent fibre content was highest at anthesis and then declined, with lowest values observed at soft dough (497–555 g/kg DM). In the majority of cases silages were well preserved, with direct ensiled material having pH values generally below 4.5 and wilted material below 5.0, with limited proteolysis as assessed by ammonia-N contents in the range of 5–15% of total-N. The production of volatile fatty acids and lactic acid was influenced by wilting and the use of additives. Generally, wilted silages fermented less than the corresponding direct ensiled forages, whereas the use of Sil-All 4 × 4 additive resulted in a lactic acid-dominant fermentation compared with LaSil additive, which resulted in a greater proportion of acetic acid as an end product of fermentation. The findings of the present study highlight the potential of forage cereals to produce high DM yields for whole crop cereal silage. The timing of harvest directly influences nutritive characteristics of forages for ensiling. The use of silage additives can assist in controlling fermentation pathways during ensilage, ensuring the production of silages with fermentation attributes more likely to lead to higher intakes when fed to animals.

Wood preservation by a mixed anhydride treatment: A 13C‐NMR investigation of simple models of polymeric wood constituents

AbstractThe treatment of wood by a mixed aceto/oleic (or other fatty acid residue) anhydride promoted as a safe and environmentally friendly wood preservation system was examined quantitatively by liquid‐phase 13C‐NMR and solid‐phase magic angle spinning–DEC (proton decoupling) 13C‐NMR through of all its different stages to determine which reactions occurred with simple model compounds of the polymeric constituents of wood. The preparation of the mixed aceto/oleic anhydride under different conditions was also undertaken. The anhydride formed, but its percentage yield was only 30%. The mix composed of unreacted acetic anhydride, the mixed aceto/oleic anhydride, and a large proportion of free acetic and oleic acid, which are used for wood preservation, yielded the acetylation of the lignin model compound (1) by the reaction of the acetic anhydride with it and (2) by the reaction of the acetic part of the mixed anhydride. In this reaction, all of the mixed anhydride was consumed. The oleic part of the mixed anhydride was unable to form esters with either lignin or wood holocellulose as it was far less reactive than the acetic part. Some acetylation of holocellulose occurred, and some traces of its oleic acid ester also occurred under some conditions. This system of treatment through a mixed anhydride appeared to consist of just an acetylation with acetic anhydride mixed with some oleic acid as a water repellent, both of which are already known processes. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

The relationship between the volatile fatty acids supply and the nitrogen retention in growing sheep nourished by total intragastric infusions

Twelve four-month old Suffolk × Small-tail- Han male sheep (live weight 21–26 kg), fitted with rumen and abomasum fistulas and nourished by total intragastric infusions, were used to study the relationship between the volatile fatty acids (VFA) supply and the nitrogen (N) retention in sheep. The animals were randomly divided into four groups and four levels of mixed VFA energy (the molar proportion of acetic acid, propionic acid and butyric acid was 65:25:10), i.e. 333, 378, 423 and 468 kJ kg −1 W 0.75 d −1, were infused into the rumen, as treatments I, II, III and IV, respectively. The results showed that the N retention was significantly increased ( P < 0.05) with the VFA infusion level. Significant regression relationship was found between the VFA supply ( x, g d −1) and the N retention ( y, mg d −1): y = 2.75 x − 403, r 2 = 0.86, n = 12, P < 0.01. It was concluded that to get efficient utilization of dietary N and high N retention in sheep, it is necessary to supply enough dietary energy.

Effects of addition of food by-products on the fermentation quality of a total mixed ration with whole crop rice and its digestibility, preference, and rumen fermentation in sheep

Four sheep were used in a 4 × 4 Latin square design experiment to study fermentation quality, digestibility, and preference of a whole crop rice (WCR) total mixed ration (TMR) silage with food by-products. Experimental treatments included control silage ( i.e., no food by-product) and 300 g/kg each of TMR dry matter (DM) as dry tofu cake (DTC), rice bran (RB) or wet green tea waste (WGTW). Silages ensiled for 60 days were well preserved with low pH (<4.06) and NH 3–N contents, and high lactic acid content. A higher ( P<0.05) content of lactic acid was observed in the DTC silage. In addition, compared to the control, the DTC and RB treatments increased the CP, EE and GE contents of the silages, and WGTW treatments increased the CP and ADFom contents of the silages. Preference was affected by inclusion of food by-products. The mean relative intake of TMR for the control, DTC, RB and WGTW silages were 0.485, 0.671, 0.397 and 0.447, respectively. Compared to the control, the DTC treatment increased silage preference, while RB and WGTW treatments decreased silage preference. No differences were observed among treatments in ruminal pH or total volatile fatty acid concentrations, but ruminal NH 3–N content was highest in the DTC silage ( P=0.0191) 2 h after feeding. The molar proportion of acetic acid in ruminal fluid was highest for the WGTW silage ( P=0.0004) 4 h after feeding. Molar proportions of propionic acid and isobutyric acid in ruminal fluid were higher for the RB silage ( P=0.0277 and P=0.0368, respectively) than for the WGTW silage before feeding, and the molar proportions of isovaleric acid and valeric acid in ruminal fluid were higher for the RB silage ( P=0.0183 and P=0.0113, respectively) than for either the WGTW or control silage before feeding. Among the three food by-products, the digestibility of DTC was highest. Findings suggest that food by-products can be used in WCR TMR silage, that the silages can be of good quality, and that silage with added DTC has high digestibility and good preference.

The Effect of Silage and Concentrate Type on Intake Behavior, Rumen Function, and Milk Production in Dairy Cows in Early and Late Lactation

The objective of this experiment was to evaluate the effect of feeding total mixed rations (TMR) that differ in structural and nonstructural carbohydrates to dairy cows in early and late lactation on short-term feed intake, dry matter intake (DMI), rumen fermentation variables, and milk yield. A 5×5 Latin square experiment with 15 dairy cows was repeated during early and late lactation. The 5 treatments were a TMR with (all on dry matter basis) 55% roughage (a 50:50 mixture of corn silage and grass silage) and 45% concentrate (a 50:50 mixture of concentrate rich in structural carbohydrates and concentrate rich in nonstructural carbohydrates; treatment CON), a TMR with the concentrate mixture and 55% grass silage (RGS) or 55% corn silage (RCS), and a TMR with the roughage mixture and 45% of the concentrate rich in structural carbohydrates (CSC) or the concentrate rich in nonstructural carbohydrates (CNS). Meal criteria, determined using the Gaussian-Gaussian-Weibull method per animal per treatment, showed an interaction between lactation stage and treatment. Feed intake behavior variables were therefore calculated with meal criteria per treatment-lactation stage combination. Differences in feed intake behavior were more pronounced between treatments differing in roughage composition than between treatments differing in concentrate composition, probably related to larger differences in chemical composition and particle size between corn silage and grass silage than between the 2 concentrates. The number of meals was similar between treatments, but eating time was greater in RGS (227 min/d) and lesser in RCS (177 min/d) than the other treatments. Intake rate increased when the amount of grass silage decreased, whereas meal duration decreased simultaneously. These effects were in line with a decreased DMI of the RGS diet vs. the other treatments, probably related to the high neutral detergent fiber (NDF) content. However, this effect was not found in CSC, although NDF content of the TMR, fractional clearance rate of NDF, and fractional degradation rate of NDF was similar between CSC and RGS. Rumen fluid pH was lesser, and molar proportions of acetic acid and of propionic acid were lesser and greater, respectively, in RCS compared with all other diets. Milk production did not differ between treatments. There was no effect of type of concentrate on milk composition, but diet RCS resulted in a lesser milk fat content and greater milk protein content than diet RGS. Lactation stage did affect short-term feed intake behavior and DMI, although different grass silages were fed during early and late lactation. The results indicate that short-term feed intake behavior is related to DMI and therefore may be a helpful tool in optimizing DMI and milk production in high-production dairy cows.

Effect of feeding Lagerstroemia speciosa and conventional fodder based rations on nutrient utilization, ruminal metabolites and body weight gain in mithun (Bos frontalis)

The aim of the present study was to evaluate the effect of feeding green fodder, rice straw and concentrate-based total mixed rations (TMR) on dry matter (DM) intake (DMI), nutrient utilization, rumen fermentation patterns and body weight (BW) gain (BWG) in mithun (Bos frontalis) calves. In a randomized block design, male mithun calves (n = 18, 8-10 months of age, 121 +/- 2 kg BW) were randomly divided into three experimental equal groups (six animals in each group) and fed isonitrogenous TMRs ad libitum for 120 days. The TMR(1) contained 30% Napier grass and 30% rice straw, TMR(2) contained 60% rice straw and TMR(3) contained 30% tree leaves (Lagerstroemia speciosa) and 30% rice straw (DM basis). All the TMRs contained 40% concentrate mixture (DM basis). The results indicated that the BWG, DMI and feed conversion efficiency were significantly (p < 0.01) increased with the inclusion of green fodder in TMRs. The apparent digestibility of DM, crude protein, ether extract, crude fibre and nitrogen free extract were also improved significantly (p < 0.01) with the inclusion of green fodder in TMRs. The higher concentration of total nitrogen and total volatile fatty acid in rumen liquor, but low ruminal pH were evident in animals fed green fodder supplemented TMRs. An increased (p < 0.01) molar proportion of acetic acid was evident in animals fed rice straw-based TMR. In contrast, the molar proportion of propionic and butyric acids were significantly (p < 0.01) higher in animals fed green fodder supplemented TMRs. On the basis of higher DMI and higher daily BWG, it is concluded that Napier grass and L. speciosa tree leaves may be incorporated upto 30% (DM basis) in TMR of growing mithuns for feeding in complete confinement system.

Intake, digestibility and rumen characteristics in cattle offered whole-crop wheat or barley silages of contrasting grain to straw ratios

The effects of varying the grain (G) to straw (S) ratio (G:S) of whole-crop wheat and barley silages on intake and digestibility and whole-crop barley silage on rumen fermentation characteristics were examined in two parallel studies. For the intake and digestibility study, eight Aberdeen Angus cross-bred steers (mean bodyweight 407 kg (S.D. 24.2)) were used in two (barley and wheat) 4 × 4 Latin Square designed experiments. The dietary treatments were four G:S ratios: 0:100, 30:70, 60:40 and 90:10. Intake of grain linearly increased ( P<0.001) while that of straw decreased ( P<0.001) as the ratio of G:S increased for both cereals. No effect ( P>0.05) was observed in total dry matter (DM) intake (DMI) or in DMI per kg liveweight. There was a positive linear ( P<0.001) effect on the digestibility of the DM and organic matter (OM) and a negative linear effect on neutral detergent fibre (aNDFom) digestibility ( P<0.01) as the G:S ratio increased for both cereals. Both a positive linear ( P<0.05) and quadratic ( P<0.01) effect were observed for the G:S ratio on nitrogen (N) digestibility of barley and a corresponding positive linear increase ( P<0.01) for wheat. A negative linear effect was found for digestibility of starch ( P<0.01) and a positive linear effect for faecal grain content ( P<0.01) with increasing G:S ratio. Four Holstein–Friesian steers (mean bodyweight 659 kg (S.D. 56.9)) fitted with rumen cannulae were used in the rumen study. A negative linear effect of G:S ratio was found on rumen pH ( P<0.001) while a positive linear effect was found on rumen ammonia ( P<0.001) and total volatile fatty acid (VFA) concentration ( P<0.01) with increasing G:S ratio. A negative linear effect ( P<0.01) was found on the molar proportion of acetic acid. However, this decrease was offset by linear increases in the molar proportions of iso- and n-butyric acid, iso- ( P<0.01) and n- ( P<0.05) valeric acid, and to a lesser extent in propionic acid ( P<0.01). No effect of treatment was found on rumen pool sizes of DM or its constituents. A positive linear effect ( P<0.01) was found on the effective degradability (ED) of the DM, OM, N and starch while it was found to be negative in aNDFom ( P<0.05). No effect ( P>0.05) was found on the fractional clearance rates of DM, OM, aNDFom or starch or on liquid passage rate. It is concluded that increasing the G:S ratio in whole-crop wheat or barley silage linearly increased the intake of digestible nutrients for both wheat and barley and increasing the G:S ratio for whole-crop barley increased the concentration of fermentation products (total VFA, ammonia and the molar proportions of the VFAs, except acetic acid) in the rumen.

미생물제제의 첨가가 면양의 반추대사 및 젖소의 유생산성에 미치는 영향

Two experiments were conducted to observe the effects of direct fed microbials on metabolic characteristics in sheep and milking performance in dairy cows. A metabolic trial with four ruminally cannulated sheep (60±6kg) was conducted in a 4×4 Latin square design to investigate the supplementation effects of Saccharomyces cerevisiae, Clostridium butyricum or mixed microbes of S. cerevisiae and C. butyricum on ruminal fermentation characteristics and whole tract digestibility. Sheep were fed 1.25 kg of total mixed ration (TMR, DM basis) supplemented with S. cerevisiae (2.5g/day), C. butyricum (1.0g/day) or its mixture (S. cerevisiae 1.25 g/day + C. butyricum 1 g/day), twice daily in an equal volume. But control sheep were fed only TMR. A feeding trial with 28 lactating Holstein cattle was also conducted for 12 weeks to investigate the effects of the same microbial supplements as for the metabolic trial on milking performance. The cows were fed the TMR (control), and fed S. cerevisiae (50 g/day), C. butyricum (15 g/day) or its mixture (S. cerevisiae 25 g/day + C. butyricum 7.5 g/day) with upper layer dressing method. Total VFA concentration and the digestibility of whole digestive tract in the sheep increased by supplementation of S. cerevisiae, C. butyricum or their combined microbials compare to control group. The proportion of propionic acid at 1 h (P<0.039) and 3 h (P<0.022) decreased by supplementation of S. cerevisiae while tended to increase acetic acid proportion at the same times. Daily dry matter intake (DMI) was not influenced by the microbial treatments, but milk yield (P<0.031) and feed efficiency (milk yield/DMI, P<0.043) were higher for the cow received C. butyricum than those for other treatments. The milk fat content was higher (P<0.085) when cows fed S. cerevisiae (4.11%) than that fed the control (4.08%), the diets with C. butyricum (3.85%) and the microbial mixture. Based on the results obtained from the current experiments, supplementation of C. butyricum or mixture

Hydrothermal upgrading of wood biomass: Influence of the addition of K2CO3 and cellulose/lignin ratio

The hydrothermal treatment of two different wood biomass samples such as cherry (hard wood) and cypress (soft wood), whose composition is different i.e. lignin, cellulose and hemicellulose were performed at 280°C for 15min with aq. K2CO3 with different concentrations (0–1M). The soft wood biomass contains higher lignin content than hard wood biomass. The cellulose rich cherry wood biomass produced higher proportion of acetic acid than cypress. The lignin rich cypress produced the hydrocarbons with major portion of phenolic hydrocarbons and derivatives than cherry. The total oil yields from both cherry and cypress wood biomass produced 50wt% of liquid hydrocarbons at 280°C for 15min with 0.5M K2CO3 solution. The volatility distribution of liquid hydrocarbons showed the characteristic features of soft and hard wood biomasses.

Adaptive capacity of faecal microbiota from piglets receiving diets with different types of inulin-type fructans

Abstract An in vitro experiment was conducted to assess the microbial activity of faeces from unweaned and weaned piglets. Diets of weaned piglets were supplemented with various fructans. Weaned piglets received a corn–soy based basal diet supplemented with either corn starch (control; CON), oligofructose (OF), chicory root (CHR), a mixture of chicory pulp and oligofructose (MIX; 60:40) or corn starch and antibiotic (CON AB ). Faecal inocula collected from unweaned (5 kg body weight (BW)) and weaned piglets (15 kg BW) were introduced in airtight 100-mL bottles containing 0.5 g of substrate (basal or mix) in pre-warmed buffered medium. The organic matter cumulative volume (OMCV) was measured for 48 h, and a mono-phasic model was fitted to the data. The concentration of volatile fatty acids (VFA) and ammonia (NH 3 ) was determined after fermentation. Incubation of substrate mix with the different inocula gave a significant higher OMCV compared to substrate basal, except for the inoculum from piglets of the CON AB group. In addition, substrate mix gave a higher R max and a lower T max compared to substrate basal. With the exception of inoculum obtained from chicory root supplemented animals (CHR) no substrate effects were observed in fermentation end-products (VFA and NH 3 ). However, the proportions of acetic acid were significantly higher and those of butyric acid lower when inocula were incubated with substrate mix. Inocula from weaned pigs tended to show higher proportions of propionic acid when incubated with substrate mix, whilst inocula from unweaned piglets showed the opposite. The differences in fermentation kinetics between substrates after incubation with inocula from weaned and unweaned piglets in combination with an altered composition in VFA, points to a modified faecal microflora following weaning.

Effects of increasing the intake of dietary β-glucans by exchanging wheat for barley on nutrient digestibility, nitrogen excretion, intestinal microflora, volatile fatty acid concentration and manure ammonia emissions in finishing pigs

An experiment (complete randomised design) was conducted to investigate the linear and quadratic effects of barley β-glucan inclusion level on total tract nutrient apparent digestibility, nitrogen excretion, intestinal microflora, volatile fatty acid (VFA) profile and manure ammonia emissions in pigs. Twenty-four boars (66 kg) were assigned to one of four treatments: (T1) 0 g/kg barley (control diet) (5.6 g/kg β-glucan), (T2) 222 g/kg barley (12.1 g/kg β-glucan), (T3) 444 g/kg barley (18.9 g/kg β-glucan) and (T4) 666 g/kg barley (25 g/kg β-glucan). Barley was substituted for wheat in the diet. The diets were formulated to contain similar concentrations of digestible energy and digestible lysine. There was a linear decrease (P < 0.001) in the total tract apparent digestibility of dry matter, organic matter, gross energy and neutral-detergent fibre with increasing β-glucan concentration. Faecal nitrogen excretion was affected by dietary β-glucan concentration (quadratic P < 0.05). There was a linear decrease in Enterobacteria concentrations (P < 0.05) with increasing dietary β-glucan concentration. Increasing dietary barley levels caused a linear decrease in colonic (P < 0.01) and caecal pH (P < 0.001). Total caecal VFA and propionic acid were affected by dietary β-glucan concentration (quadratic, P < 0.05). There was a linear decrease in the proportion of acetic acid (P < 0.001), isobutyric acid (P < 0.01) and isovaleric acid (P < 0.05) with increasing levels of dietary barley in both the caecum and colon. There was a linear increase in the proportion of propionic acid (P < 0.001) and butyric acid (P < 0.05) with increasing barley in the colon. In conclusion, high level of dietary β-glucan (25 g/kg) is required to reduce offensive odour forming branched-chain VFAs; however, diet digestibility is compromised at such levels.

The effect of expander processing and screen size on nutrient digestibility, growth performance, selected faecal microbial populations and faecal volatile fatty acid concentrations in grower–finisher pigs

A 2 × 2 factorial experiment with grower–finisher pigs was conducted to investigate the effect of screen size and expander processing (yes and no) on digestibility, pig performance, selected faecal microbial populations and faecal volatile fatty acid concentrations. The feed was ground at two levels (using a 3 or 6 mm hammermill screen) to obtain a fine or coarse feed and given to the pigs as either raw or expanded feed. The diets were expander processed at 105 °C for 5 s at 35-bar pressure. Fine grinding increased the coefficient of total tract apparent digestibility (CTTAD) of gross energy of the diets (P<0.05) and reduced faecal dry matter concentration (P<0.05). Pigs offered the 3 mm diets had a lower (P<0.05) feed intake (2.47 kg/day versus 2.55 kg/day, S.E.M. 0.029) and a better (P<0.01) feed conversion ratio (2.61 kg/kg versus 2.80 kg/kg, S.E.M. 0.034) than the pigs offered the 6 mm diets. Expander processing had no effect on CTTAD or growth performance. There was a significant interaction (P<0.05) between screen size and expander processing on the faecal Lactobacilli and Enterobacteria population. Coarse grinding increased (P<0.05) the faecal Lactobacilli population and decreased (P<0.05) faecal Enterobacteria population when the diets were not heat treated. However, screen size had no effect on Lactobacilli and Enterobacteria population when the diets were expanded. Coarse grinding increased (P<0.05) the total faecal volatile fatty acid concentration and molar proportions of propionic acid and butyric acid while decreasing (P<0.05) the faecal proportions of acetic acid compared to fine grinding. In conclusion, fine grinding of feed improved feed intake and feed conversion ratio. However, it did increase faecal Enterobacteria populations. Expander processing had no effect on pig performance.

Influence of the amount of dietary fiber on the available energy from hindgut fermentation in growing pigs: Use of cannulated pigs and in vitro fermentation1

Available energy from hindgut fermentation to pigs fed various amounts of dietary fiber was investigated using an in vivo-in vitro methodology. Six growing pigs fitted with a simple T-shaped cannula at the terminal ileum, and following a Latin-square design, were fed 3 diets differing in the content of non-starch polysaccharides (NSP): a low fiber diet (LFD, 77 g/kg of DM), a standard fiber diet (SFD, 160 g/kg of DM), and a high fiber diet (HFD, 240 g/kg of DM). After adaptation to the diet for 10 d, samples from feces and ileum were collected and analyzed for DM, energy, NSP, and chromic oxide; feces were also analyzed for short chain fatty acids (SCFA). Freeze-dried ileal samples (10 g/L) were fermented in vitro in a fecal slurry consisting of an anaerobic mineral salt medium and feces (50 g/L) from cannulated pigs fed the same diets. Available energy was calculated from the amount of SCFA produced in vitro after 48 h of incubation. Nonstarch polysaccharide content in the fermented material was measured to assess the in vitro degradation of this fraction. Increasing dietary NSP from 77 to 240 g/kg of feed DM increased (P < 0.001) ileal flow from 199 to 468 g/kg of feed, leading to a reduction in the energy digested at the terminal ileum, from 15 to 11 MJ/kg of feed DM and an increment in energy digested in the hindgut, from 1.6 to 3.5 MJ/kg of feed DM. Total in vitro production of SCFA/kg of feed DM was dependent on the amount of ileal substrate available for fermentation; that is, increased concentrations of NSP in the diet led to an increase in the SCFA that may be available to the animal (P < 0.001). The molar ratio of SCFA produced in vitro was affected by diet; the high fiber diet showed the greatest (P = 0.004) proportion of acetic acid, and the low fiber diet showed a tendency (P = 0.081) to an increased butyric acid proportion compared with the other 2 diets. Net disappearance of NSP during fermentation in vivo and in vitro were compared and showed a close relationship (P < 0.001, slope = 0.906, r = 0.960). In our experimental conditions, available energy as SCFA to the animal from hindgut fermentation increased with the concentration of dietary NSP (P < 0.001) and provided between 7.1 and 17.6% of the total available energy.