Dry Matter Degradation Kinetics Research Articles

Effect of Acacia mearnsii forage or tannin extract on rumen dry matter and crude protein degradation.

This study investigated rumen degradation kinetics of dry matter (DM) and crude protein (CP) in compound feed with different tannin extract inclusions and Acacia mearnsi forage (AMF) relative to dairy feeds (perennial ryegrass+white clover mixture pasture, maize silage, lucerne hay and Themeda triandra hay). The compound feed had 0.75%, 1.5% and 3% tannins extract inclusions while the control was a commercial compound feed. Triplicates of each feed per incubation period were incubated in two fistulated Jersey cows for 0, 6, 24, 48, 72, 96 and 120 h, resulting in six replicates per feed. Tannin extract inclusions in compound feed only affected (p < 0.05) the (a) fraction, degradation rate and potential degradability (PD) for DM degradation, and affected (p < 0.05) the (a) and (b) fractions, as well as PD for CP degradation. The (a) fraction and degradation rate for DM degradation changed linearly (p < 0.05). The (a) fraction, PD and effective degradability (ED) of DM degradation changed quadratically (p < 0.05). Except for the degradation rate, the feed type affected (p < 0.05) the degradation parameters in both DM and CP degradations. For DM and CP degradations, (a) fraction was similarly the least in Themeda triandra hay and AMF but similarly the highest in maize silage, perennial ryegrass+white clover mixture pasture and lucerne hay. The (b) fraction was the least in AMF for both DM and CP degradations but the highest for pasture's DM degradation and similarly the highest in maize silage, lucerne hay and T. triandra hay for CP degradation. The PD was the least in AMF for both DM and CP degradations and similarly the highest in pasture DM but similarly the highest in perennial ryegrass+white clover mixture pasture, maize silage and lucerne hay for CP degradation. Furthermore, the ED was the lowest in AMF and the highest for perrenial ryegrass + white clover mixture pasture for DM degradation and same trend was observed for CP degradation whereby perrenial ryegrass + white clover mixture pasture, maize silage and lucerne had the highest ED. Digestible undegraded protein was the highest in AMF and similarly the least in dairy feeds. Tannin source inclusion in ruminant diets should be moderate to prevent rumen DM or CP degradation limitation.

Effect of Tannin Inclusion on the Enhancement of Rumen Undegradable Protein of Different Protein Sources

Tannins can be utilized to increase rumen undegradable protein (RUP) by their capacity to form complexes with diverse nutrients present in the feed. In that regard, high-performance ruminants demand elevated RUP levels. The objective of this study was to evaluate the effects of incorporating varying levels of tannin into three protein sources (cottonseed, peanut, and soybean meals) on ruminal kinetic parameters, ruminal fermentation, and intestinal digestibility. Thus, three in situ experiments were conducted to investigate the ruminal degradation kinetics, where Fraction A represents the soluble portion, Fraction B relates to the portion potentially degraded in the rumen, and kd denotes the degradation rate of Fraction B, for both dry matter (DM) and crude protein (CP) in the rumen. Additionally, the study assessed dry matter effective degradability (ED), rumen undegradable protein (RUP), and intestinal digestibility (ID). These experiments utilized three cannulated animals for the in situ incubations. Regarding cottonseed meal in terms of DM degradation kinetics, tannin inclusion had a quadratic effect on fraction A (p &lt; 0.01), B (p = 0.10, trend), kd (p = 0.03), and ED (p &lt; 0.01). Fraction A of CP had a cubic effect (p = 0.03), being greater for the control compared with the other treatments. The inclusion of tannin linearly increased RUP (p &lt; 0.01). The RUP proportion increased 29, 33, and 45% when 20, 40, and 60 g/kg tannin were used, respectively, compared to the control. For peanut meal, the A fraction of protein and RUP responded quadratically as tannin was included in peanut meal (p &lt; 0.01). However, tannin levels did not affect fraction B of protein and ID. Regarding soybean meal, fractions A and B of DM and ED had cubic effects (p &lt; 0.01), being greater for the control compared with the other treatments, and responded quadratically as tannin increased. Also, tannin inclusion had a cubic effect on fractions A and B of protein, RUP, and ID (p &lt; 0.01). The cubic behavior showed greater B fraction and ID and lower A fraction and RUP for the control compared other treatments (p &lt; 0.01). Tannins offer a promising avenue for elevating RUP levels in diets featuring cottonseed and peanut meals. Nevertheless, no advantages were observed when treating soybean meal with tannin.

Replacing alfalfa hay with triticale hay has minimal effects on lactation performance and nitrogen utilization of dairy cows in a semi-arid region of Mexico

In the semi-arid highlands of central Mexico, triticale (× Triticosecale L.) is emerging as an alternative, less water-demanding forage crop than alfalfa for dairy cattle. Studies reported here were aimed at evaluating triticale hay (TH) relative to alfalfa hay (AH) for lactating cow performance, apparent digestibility, N partition, and ruminal degradation kinetics of dry matter (DM), crude protein (CP), and neutral detergent fiber (NDF). Study 1 was conducted on a privately owned farm. Four barns were used to conduct 4 replicated 3 × 3 Latin squares (1 barn = 1 square), where each barn included 3 pens (experimental units) receiving 1 of 3 dietary treatments. Each pen had 62 Holstein dairy cows. All diets included a forage-to-concentrate ratio of 42:58 (DM basis), which is typical for intensive dairy farms of the region. Dietary treatments were formulated to replace AH with TH on a CP basis, and included (DM basis) 15.1% AH and 0% TH, 9.0% AH and 7.4% TH, and 0% AH and 16.4% TH. Diets were iso-energetic (1.64 Mcal of net energy for lactation/kg of DM) and iso-nitrogenous (17.9% CP). Pen-level DM intake and milk production were from all cows in the pen, but pen-level milk composition, apparent digestibility, and N partitioning were from 8 cows (observational units) randomly selected in each pen. Orthogonal contrasts were used to determine linear and quadratic effects of increasing TH from 0 to 7.4, and 16.4% of dietary DM. Although DM intake was not affected, there was a tendency for CP intake to decline linearly and for NDF intake to increased linearly as TH replaced AH in the diet. Milk production declined linearly by 0.077 kg/d for each additional percentage unit of TH in the diet, which amounted to a 3.5% decline when TH replaced AH entirely. However, no effect was observed on energy-corrected milk production because of a compensatory linear effect of increasing milk fat concentration with the incorporation of TH in the diet. Total-tract NDF digestibility tended to increase linearly by 18.5%, but no differences were detected for urinary urea-N excretion and for N utilization estimated as milk N/(fecal N + urinary N + milk N). Study 2 was an in situ trial conducted to determine the degradation kinetics of AH and TH used in study 1. In spite of differences in degradation kinetics parameters for DM, CP, and NDF, only NDF effective ruminal degradation tended to be greater for TH than AH. Replacing AH with TH at the level typically found in intensive dairy farms of the semi-arid regions of Mexico had minimal effects on milk production and N utilization.

In vitro fermentation and in situ rumen degradation kinetics of summer forage brassica plants

The aim of the present study was to assess and compare the nutrient concentration, the in vitro fermentation and the in situ rumen degradation characteristics of Brassica rapa ssp. rapa L. (turnips) and Brassica napus ssp. biennis L. (forage rape). Five varieties of each species were established in three field replicates and were organised in a randomised complete-block nested design. All varieties were harvested and further analysed for chemical composition, in vitro gas-production kinetics, volatile fatty acid (VFA) production and in situ degradation kinetics of dry matter (DM) and crude protein. Turnips showed higher ash, total sugars, raffinose, sucrose, glucose and fructose concentrations (P &amp;lt; 0.001) than did forage rape. Turnip varieties differed in their sucrose, glucose, fructose and total soluble sugar concentration (P &amp;lt; 0.001), whereas rape varieties differed in their neutral detergent fibre concentration (P = 0.004) and digestible organic matter on a DM basis (P &amp;lt; 0.01). Regarding DM-degradation parameters, turnips had a higher soluble fraction ‘a’ (P &amp;lt; 0.01) and a lower insoluble, but potentially degradable fraction ‘b’ (P &amp;lt; 0.01) than did rape, but the fractional degradation rate ‘c’ (0.18/h) was similar to that of rape. Rates of gas production were slightly higher (P = 0.018) for turnip than for rape. No effects for brassica species nor for varieties within species were detected (P &amp;gt; 0.05) for total in vitro VFA production, as well as for the relative proportions of acetate, propionate, butyrate, branch chained VFA and the actetate:propionate ratio. Our study showed that most of the differences that were observed in terms of chemical composition and degradation kinetics did not result in differences in in vitro fermentation products.

Improving the performance of dairy cattle with a xylanase-rich exogenous enzyme preparation

The objective of this experiment was to examine effects of adding 2 exogenous fibrolytic enzymes (EFE) to the total mixed ration (TMR) on the performance of lactating dairy cows (experiment 1) and the kinetics of ruminal degradation of the diet (experiment 2). Twelve EFE had been screened in a series of in vitro assays that identified the most potent EFE and their optimal doses for increasing the digestibility of bermudagrass. In experiment 1, 66 Holstein cows (21±5 d in milk) were grouped by previous milk production and parity (45 multiparous and 21 primiparous) and assigned randomly to 1 of the following 3 treatments: (1) control (CON, untreated), (2) Xylanase Plus [2A, 1mL/kg of TMR dry matter (DM); Dyadic International, Jupiter, FL], and (3) a 75:25 (vol/vol) mixture of Cellulase Plus and Xylanase Plus EFE (3A, 3.4mL/kg of TMR DM; Dyadic International). The EFE were sprayed twice daily onto a TMR (10% bermudagrass silage, 35% corn silage, 5% alfalfa-orchardgrass hay mixture, and 50% concentrates; DM basis) and fed for a 14-d training and covariate period and a 70-d measurement period. Experiment 2 aimed to examine the in situ DM ruminal degradability and ruminal fermentation measurements of the diets fed in experiment 1. Three ruminally fistulated lactating Holstein cows were assigned to the diets. The experiment had a 3×3 Latin square design with 23-d periods. In experiment 1, application of 2A increased intakes (kg/d) of DM (23.5 vs. 22.6), organic matter (21.9 vs. 20.9), and crude protein (3.9 vs. 3.7) and tended to increase yields (kg/d) of fat-corrected milk (41.8 vs. 40.7) and milk fat (1.48 vs. 1.44). In particular, 2A increased milk yield (kg/d) during wk 3 (41.2 vs. 39.8, tendency), 6 (41.9 vs. 40.1), and 7 (42.1 vs. 40.4), whereas 3A increased milk yield (kg/d) during wk 6 (41.5 vs. 40.1, tendency), 8 (41.8 vs. 40.0), and 9 (40.9 vs. 39.5, tendency). In experiment 2, EFE treatment did not affect ruminal DM degradation kinetics or ruminal pH, ammonia-N, and volatile fatty acid concentration. Application of 2A to the bermudagrass-based TMR increased DM intake and milk production, implying that this EFE could be used to increase the performance of lactating dairy cows fed diets containing up to 10% bermudagrass.

Effect of starch content and processing method on in situ ruminal and in vitro intestinal digestion of barley grain in beef heifers

Rate of barley starch digestion in the rumen is critical issue in high-grain fed beef cattle because it is associated with growth performance and health. The digestion rate of starch varies with variety, grain processing or starch content. The objectives of this study were to evaluate the effect of starch content and processing method of barley grain on in situ ruminal dry matter (DM) and starch digestion kinetics, and to develop a model to predict the rate of DM digestion of barley grain. The study was a 2×2 factorial arrangement of treatments: starch content (low vs. high) and processing method (PM; grinding vs. dry rolling). Ten barley samples with 5 low (571±17g/kg) and 5 high (660±7g/kg DM) starch were either ground 2mm or dry-rolled with processing index (PI) of 0.75 (PI=bulk density processed/bulk density whole). Three beef heifers (650kg body weight) fitted with rumen cannulas and fed diet consisting (g/kg DM) of 700 barley silage and 300 barley grain were used for in situ incubation. In situ degradation kinetics of DM, starch, neutral detergent fibre (NDF) and crude protein (CP) were estimated after 0, 2, 4, 8, 12, 24, and 48h of ruminal incubation. Data from DM, starch, NDF and CP degradation at different times of incubation were fitted to a model y=a+b(1−e−c(t−L)). In vitro intestinal disappearances of DM, starch, NDF and CP of ruminal residue after 12h of incubation were determined using a modified three-step procedure. Interactions between starch content and PM on the degradation kinetic parameters of DM, starch, NDF and CP were seldom observed. High starch barley had greater (P<0.01) a and effective degradability (ED) of DM and starch, but it had less (P=0.03) b of starch versus low starch barley. Ground barley had greater (P<0.01) a, c and ED of DM and starch, and lower (P<0.01) b compared with dry-rolled barley. Intestinal disappearance DM and starch of rumen residues were affected by both starch content and PM. Starch content of barley grain and manipulating processing method could effectively alter rumen digestion of barley grain.

Relationship between fibre degradation kinetics and chemical composition of forages and by-products in ruminants

This experiment was conducted to investigate the relationship between fibre degradation kinetics and chemical composition of forages and by-products using nylon bag technology. Four rumen fistulated goats fed a medium concentrate diet were used to measure degradation kinetics of dry matter (DM), neutral detergent fibre (NDF) and acid detergent fibre (ADF). Fourteen feed samples included 6 forage species (ryegrass, coronilla, clover, alfalfa, corn plant and wheat straw) and 2 by-product species (cottonseed hulls and corn cobs). Nylon bags were ruminally incubated for 0, 6, 12, 24, 48 and 72 h. NDF content of these feeds ranged from 35.7% to 93.8% of DM. Effective degradability of DM (DMD), NDF (NDFD) and ADF (ADFD) ranged from 6.0% to 76.3%, 4.2% to 52.5% and 3.2% to 41.1%, respectively. DMD, NDFD and ADFD were positively correlated with crude protein content (P < 0.05) but negatively with the content of NDF, ADF and lignin (P < 0.05). NDF content was the best feed composition for predicting DMD, NDFD and ADFD of forages and by-products. These results suggested that chemical analysis could give a satisfactory prediction towards degradable characteristics of fibrous feedstuffs in ruminants.

Inclusão do substrato de shimeji-preto na cinética de fermentação in vitro do feno de Brachiaria brizantha

The objective of this study was to evaluate the effect of inclusion of exhausted substrate of Pleurotus ostreatus on the in vitro fermentation of Brachiaria brizantha hay-based diets. The experiment was conducted using the semi-automated gas production technique. The ruminal inoculum was collected from three fistulated cattle kept on Brachiaria brizantha pasture. Brachiaria brizantha hay and exhausted substrate of Pleurotus production were used for composition of the diets: ES (100% exhausted substrate), BH (100% Brachiaria brizantha hay), ES5 (5% ES + 95% BH), ES20 (20% ES + 80% BH), and ES30 (30% ES + 70% BH). The experimental design was a 5x3 factorial scheme consisting of five treatments and three ruminal inocula. The degradation kinetics of dry matter (DM) was determined after 96 hours of fermentation [D (96h)]. No significant differences in the cumulative volume of gas (A) were observed between BH (262.6 mL/g DM), ES5 (284.3 mL/g MS), ES20 (256.6 mL/g MS) and ES30 (261.7 mL/g MS), indicating that inclusion of the substrate did not affect hay fermentation. A lower gas volume (165.9 mL) and lower degradability (52%) were observed for the ES diet, showing a lower nutritional value of this substrate compared to Brachiaria brizantha hay, probably due to the action of enzymes that degrade structural carbohydrates found in the mycelia of Pleurotus. The ES diet exhibited a shorter colonization time (L=2.6 h; P<0.05), a finding that may be attributed to the interaction between the mycelium and substrate, facilitating initial colonization. The inclusion of exhausted substrate did not increase microbial growth or degradation compared to the BH diet, but seems to have favored initial colonization of this substrate. The use of ES does not negatively affect colonization and may be used as an ingredient of ruminant diets.

Chemical Composition, DM and NDF Degradation Kinetics in Rumen of Eleven Different Date Pits

Aims: Study was undertaken to measure chemical composition and degradation kinetics of dry matter and neutral detergent fiber in the rumen for eleven different date pits that where cultivated in different parts of Iran. Study design: Ruminal degradation kinetics of the pit samples were determined using 3 Holstein steers (450-500kg body weight), fitted with permanent rumen fistulas. Data were fitted using an exponential equation of P=W+D (1−e −kd×(t-T) ), where P is the potential of degradability, W is the quickly degradable fraction, D is the slowly degradable fraction; kd is the fractional degradation rate, t is the incubation time (h) and T is the lag time (h). Place and Duration of Study: The study took place at the Ruminant Nutrition Research Center of Agriculture Faculty of Ferdowsi University of Mashhad which placed at Mashhad urban zone. This study lasted 3 months. Methodology: Chemical composition, in situ DM and in situ NDF degradation kinetics in rumen of eleven different date pits (Barahi, Kabkab, Kharak, Khasi, Mazafati, mordabsang, Piarom, Rabbi, Estamaran, Shahani and Zahedi) were evaluated. Results: CP ranged from 5.00 to 6.90% DM and Mazafati pit had highest NDF content Original Research Article Annual Research & Review in Biology, 4(23): 3524-3531, 2014 3525 (78.23% DM) and Mordasang had highest ADF content (59.73% of DM) while Estamaran had lowest NDF and ADF content (68.90 and 50.50% of DM respectively). Mordabsang had the lowest W-fractionDM (0.104h) and Estamaran had the highest D-fractionDM (0.485). In contrast, Estamaran, Khasi, Mazafati and Zahedi had the highest (0.300, 0.301, 0.304 and 0.301 respectively) W-fractionDM and Piarom had lowest (0.323) D-fractionDM. The kdDM varied from 0.021/h (Mordasang) to 0.119/h (Estamaran). Piarom had the lowest WfractionNDF (0.011) and Estamaran had the highest W-fractionNDF (0.046). In contrast, Mazafati had the highest (0.603) and Piarom had lowest (0.394)) D-fractionNDF. Among the samples kdNDF varied from 0.021/h (Kharak) to 0.038/h (Estamaran). Conclusion: In conclusion our results show that pits of these date varieties can be used as fiber source for ruminants and their relatively high EE content may be useful as an energy source.

In situ rumen degradation kinetics as affected by type of pasture and date of harvest

Botanical composition affects the nutritive value and nutrient degradation kinetics of pastures. However, there is little information about pastures composed of various species. The present study was conducted to evaluate in situ degradation kinetics of dry matter (DM), crude protein (CP) and neutral detergent fiber (NDF) of a naturalized non fertilized pasture (NNF), naturalized fertilized pasture (NF), sown pasture with Lolium perenne L. and Trifolium repens L. (RGWC), and sown pasture with Bromus valdivianus Phil., Dactylis glomerata L., Holcus lanatus L., L. perenne and T. repens (MIXED); at three dates of harvest (early-spring, mid-spring and autumn). Duplicate bags were incubated in the rumen of three cannulated cows for 2, 4, 8, 12, 24 or 48 h. Zero-hour bags were washed with water. Ruminal degradation was evaluated according to exponential models with or without lag phase. Pasture chemical composition showed on average low DM, high CP and digestible organic matter (DOMD). Degradation parameters of DM, CP and NDF exhibited strong pasture type*date of harvest interactions. In general, high potential degradability and fractional degradation rates of DM, CP and NDF were observed. Nutrient supply was generally higher for RGWC and NF, especially compared with NNF during autumn. Naturalized fertilized pastures supply similar amounts of nutrients to grazing cattle as sown pastures. However, it is necessary to consider other variables that determine the productive performance such as DM intake and rumen fermentation products.

Qualidade do feno de capim-de-raiz (Chloris orthonoton, doell) em pequenos ruminantes

The objective of this study was to characterize the chemical composition, intake and digestibility of dry matter (DM) and nutrients, ruminal degradation kinetics of DM and NDF and quantify the nitrogen balance in sheep fed Chloris Orthonoton hay. The experiment was carried out with five sheep with 28.34 kg LW. The hay showed 90.66 % DM, 7.16 % CP and 65.34 % NDF. The digestibility of dry matter, crude protein and NDF were 52.8, 70.6 and 40.4 %, respectively. The animals showed low dry matter intake (1.4 % of BW), but positive nitrogen balance. Chloris Orthonoton hay when done in flowering stage has a low nutritional value and is not recommended as single source of food for maintenance of sheep.

Ruminal dry matter and crude protein degradation kinetics of five sainfoin (Onobrychis viciifolia Scop) accessions differing in condensed tannin content and obtained from different harvests

Sainfoin is known to vary in content of condensed tannins (CT) among accessions and harvests. In the present study, the hypothesis was tested that this results in significant differences in ruminal degradation kinetics and, with that, suitability to be used for certain purposes like increasing ruminal by pass of protein. The in sacco ruminal degradation kinetics of dry matter (DM) and crude protein (CP) of five Swiss sainfoin accessions comprising of three landraces (Moiry, Sarzens and Premier, all single flowering) and two commercial cultivars (Visnovsky and Perly, both multiple flowering) were determined with three ruminal fistulated cows. In doing so, the first and the second harvest (after 42 d of regrowth) in the second year of establishment of the plots were compared. Cultivation was done in triplicate on each of three different sites in Switzerland. Data was subjected to analysis of variance including all main effects and interactions. Finally, compositional data on CT, CP and fibre was correlated with effective ruminal degradability (ED) of DM and CP to assess how well these could be predicted. Accession hardly influenced either the degradation kinetics and effective degradability of DM and CP despite the varying chemical composition of accessions. Exceptions were the degradable but insoluble fraction, B, in DM (P=0.050) and CP (P=0.041) and the potential degradable fraction, D, in CP (P=0.017) which were influenced by accession. Conversely, harvest influenced (P<0.05) degradation kinetics and effective degradability of DM the most but not the kinetics and effective degradability of CP. The ranking of accessions was not completely consistent in the different degradation variables. However, according to the results of the multiple regression analysis, ED of DM (P=0.001) and CP (P≤0.013) declined with increasing CT content. These relationships were roughly linear. Accordingly, ED was often higher in samples from first compared to the second harvest. Most striking was, however, that only some accessions exhibited consistent and marked changes in both DM and CP degradation kinetics from the first to the second harvest whereas others did not. It appears that the first group particularly included the commercial accessions which were multiple flowering cultivars and the second group comprised the single flowering landraces. This finding could be used to select accessions with predictably stable ruminal degradability.

Genotypic variation in in sacco dry matter degradation kinetics in perennial ryegrass (Lolium perenne L.)

Fast degrading perennial ryegrass (Lolium perenne L.) is a desirable characteristic to select for because it can result in increased feed intake by grazing ruminants. Sufficient range in genotypic variation of dry matter (DM) degradation kinetics is a prerequisite for selection. To investigate the genotypic variation, 77 perennial ryegrass accessions sourced internationally, grown in autumn in the same conditions and harvested in the vegetative state, were examined using an in sacco technique. From the time course of DM disappearance, soluble fraction ‘A’, potentially degradable fraction ‘B’, indigestible fraction ‘C’ and the degradation rate k of fraction ‘B’ were estimated. The results indicated that a large range in genotypic variation was present in all degradation parameters. Fraction ‘A’ ranged from 0.48 to 0.60, with the highest five accessions being 21% higher than the lowest five. Degradation rate k of fraction ‘B’ ranged from 0.069 to 0.199/h, with the fastest five being 125% higher than the slowest five. There were no strong correlations between degradation parameters and chemical composition. In conclusion, there was considerable genotypic variation in DM degradation kinetics among perennial ryegrass accessions and this presents plant breeders with ample opportunity to select for fast degrading perennial ryegrasses.

Dry Matter Degradation Kinetics and Metabolizable Energy of Chickpea (Cicer arietinum) Straw in Ruminants

Chickpea straw is the main by-product which is produced in large amounts after chickpea grain threshing. There is a little information about its nutritive value. This experiment was carried out to determine the fiber and non-fibre component, ruminal dry matter degradability and Metabolizable Energy (ME) of chickpea straws using nylon bags (in situ) technique. Replicated samples were incubated at 0, 2, 4, 8, 12, 24, 48 and 72 h in 3 rumen canulated male Ghezel rams with 50±3 kg body weight. Dry Matter (DM), Neutral Detergent Fibre (NDF), Acid Detergent Fibre (ADF) and Non-Fibrous Carbohydrates (NFC) content of chickpea straws were 92.18, 57.80, 37.40 and 22.65%, respectively. The dry matter soluble fraction (a), non-soluble but potentially degradable fraction (b) and potential degradability (a+b) of chickpea straws were 19.50, 38.60 and 58.10%, respectively. Effective degradability at different passage rates (2, 5 and 8% h-1) were 53.70, 48.60 and 44.80%, respectively. Estimated metabolizable energy of chickpea straw was 8.55 MJ kg-1 DM. Based on the DM degradation kinetics and energy content, beseems chickpea straw could be used as a valuable feedstuff in ruminants diet

Effect of ethanol concentration on the kinetics of ruminal degradation of soybean meal

Effects of ethanol treatment on ruminal in situ degradation kinetics of dry matter (DM) and crude protein (CP) of soybean meal (SBM) were determined. Soybean meal samples were soaked in 500, 600 or 700 ml/l ethanol solutions for 2 h. Duplicate nylon bags of untreated or treated SBM were suspended in the rumen of four non-lactating Holstein cows for up to 48 h, and resulting data were fitted to non-linear degradation model to calculate degradation parameters of DM and CP. Intestinal CP digestibility was measured using the mobile nylon bag technique. Proteins of untreated and treated bag residues were fractionated by gel electrophoresis. There were differences (P<0.05) for DM and CP degradation parameters between untreated and ethanol treated SBM. Regardless of the concentration, ethanol treatments applied to SBM decreased the washout fraction, the estimated rate of CP degradation, and the effective protein degradation (EPD) compared to untreated SBM. The lowest estimated rate of CP degradation and the calculated EPD were observed when SBM was treated with 600 ml/l ethanol solution. Extending the ethanol concentration over 600 ml/l to SBM was considered excessive. Ethanol treatments increased (P<0.05) the intestinal mobile bag digestibility of ruminally undegraded CP. At concentration of 500, 600 and 700 ml/l, digestibility of CP increased by 4, 12 and 13% compared to untreated SBM, respectively. Electrophoretic analyses of untreated, 500, 600 and 700 ml/l ethanol treated SBM revealed that two of the subunits of β-conglycinin (ά and α) had been degraded completely after 2, 6, 8 and 8 h, whereas the β subunit of this protein has been degraded after 4, 8, 12 and 12 h, respectively. In untreated SBM, the acidic and basic subunits of glycinin had been degraded in 8 and 12 h of incubation, but in treated SBM had not been degraded even after 48 h of incubation. Based upon these results, treatment of SBM with 600 ml/l ethanol solution had the greatest potential to increase rumen undegradable protein.

Comparison between in situ dry matter degradation and in vitro gas production of tannin-containing leaves from four tree species

Dry matter (DM) degradation of Glycrrhiza glabra L, Arbutus andrachne, Juniperus communis , and Pistica lentiscus was determined using two different techniques: (i) the in vitro gas production and (ii) the in situ nylon bag degradability technique. Samples were incubated in situ and in vitro for 3, 6, 12, 24, 48, 72 and 96 h. In situ and in vitro DM degradation kinetics were described using the equation y = a + b (1 - e ct). At all incubation times except 3 and 72 h the cumulative gas production of J. communis was significantly lower than that of G. glabra, A. andrachne and P. lentiscus . At 3, 6 and 12 h incubation times the DM disappearance of J. communis was only significantly lower than that of P. lentiscus . At 24 and 48 h incubation times DM disappearance of J. communis was significantly lower than that of A. andrachne and P. lentiscus . There were significant relationships between in vitro gas production and in situ DM disappearance at 24 h and 96 h incubation times. The gas productions at 24 and 96 h incubation explained 51.2 and 52.4% of variation of DM disappearance, respectively. Gas production from the insoluble fraction (b) alone explained 66.4% of the variation of effective DM degradability (EDMD). The inclusion of gas production from quickly soluble fraction (a) and rate constant (c) of gas production in the regression equation did not improve the accuracy of predicting EDMD. It was concluded that in situ DM disappearance parameters of tannin-containing tree leaves such as used in this present study may be predicted from in vitro gas production parameters. South African Journal of Animal Science Vol. 34(4) 2004: 233-240

Comparison of In situ Dry Matter Degradation with In vitro Gas Production of Oak Leaves Supplemented with or without Polyethylene Glycol (PEG)

Dry matter (DM) degradation of leaves from Quercus cercis, Quercus libari, Quercus branti, and Quercus coccifera was determined using two different techniques: (i) in vitro gas production and (ii) the nylon bag degradability technique. In vitro gas production in the presence or absence of PEG and in situ DM disappearance were measured at 3, 6, 12, 24, 48, 72 and 96 h. In situ and in vitro DM degradation kinetics were described using the equation y = a+b (1-e -ct ). At all incubation times leaves from Quercus branti incubated with or without PEG gave significantly higher gas production than the other oak leaves except for 3 and 6 h incubation when leaves from Quercus branti without PEG supplementation only gave higher gas production than Quercus cercis and Quercus coccifera. At all incubation times except at 3, 6 and 12 h the DM disappearance from Quercus branti was significantly higher than the other species. Generally, PEG supplementation considerably increased the gas production at all incubation times and estimated parameters such as gas production rate (c gas ), gas production (ml) from the quickly soluble fraction (a gas ), gas production (b) from the insoluble fraction, potential gas production (a+b). However, all oak leaves did not give the same response to the PEG supplementation. Although the increase in gas production at 96 h incubation time was 8.9 ml for Quercus libari the increase was 5.5 ml for Quercus coccifera. It was concluded that except at early incubation times the relationships between the two methodologies seem to be sufficiently strong to predict degradability parameters from gas production parameters obtained in the presence or absence of PEG.

Comparison of in vitro gas production technique with in situ nylon bag technique to estimate dry matter degradation

Dry matter (DM) degradation of wheat straw (WS), barley straw (BS), lucerne hay (LH) and maize silage (MS) was determined using two different techniques: (i) in vitro gas production and (ii) nylon bag degradability technique. In vitro gas production and in situ DM disappearance were measured after 3, 6, 12, 24, 48, 72 and 96 hours of incubation. In situ and in vitro DM degradation kinetics was described using the equation y = a + b (1 &amp;ndash; e&lt;sup&gt;ct&lt;/sup&gt;). In all incubations there were significant (P &amp;lt; 0.001) correlations between gas production and in situ DM disappearance or estimated parameters ((a + b)&lt;sub&gt;ga&lt;/sub&gt;&lt;sub&gt;s&lt;/sub&gt; and (a + b)&lt;sub&gt;is&lt;/sub&gt; or (a + b)&lt;sub&gt;gas&lt;/sub&gt; and EDMD&lt;sub&gt;is&lt;/sub&gt;) whereas there were no significant (P &amp;gt; 0.05) correlations between c&lt;sub&gt;gas&lt;/sub&gt; and c&lt;sub&gt;is&lt;/sub&gt; or b&lt;sub&gt;gas&lt;/sub&gt; and b&lt;sub&gt;is&lt;/sub&gt;. Gas production from the insoluble fraction (b) alone explained 98.3% of the variation of EDMD. The inclusion of gas production from the quickly soluble fraction (a) and rate constant (c) of gas production in the regression equation improved the accuracy of EDMD prediction. The correlations between the results of both methodologies seem to be sufficiently strong to predict degradability parameters from gas production parameters. It was concluded that the in vitro gas production technique has good potentiality to predict in situ DM disappearance and some DM degradation parameters. &amp;nbsp; &amp;nbsp;

Taxas de passagem e cinética da degradação ruminal em bezerros holandeses alimentados com dietas contendo diferentes níveis de concentrado

RESUMO - Este trabalho foi realizado para avaliar os efeitos de diferentes níveis de concentrado sobre as taxas de passagem de fluidos, usando Co-EDTA, e partículas, usando cloreto de Iterbio e Cr-mordante e, a cinética da degradação ruminal in situ da matéria seca (MS) e da proteína bruta (PB). Cinco bezerros holandeses, inteiros, fistulados no rúmen e abomaso, com idade de 5,8±0,7 meses e de e 107,4±11,0 kg PV médio inicial, foram distribuídos a um delineamento em quadrado latino 5x5 (tratamento x período). Os animais foram alojados em baias individuais e alimentados à vontade com dietas contendo 30,0; 45,0; 60,0; 75,0; e 90,0% de concentrado, com base na MS, em rações contendo como volumoso, o feno de capim coast-cross e no concentrado, o farelo de sojae , fubá de milho. A taxa de passagem de fluidos apresentou comportamento quadrático, estimando-se o valor máximo de 9,73%/h, com nível de 61,99% de concentrado na ração. A taxa de passagem de partículas do farelo de soja no retículo-rúmen- diminuiu linearmente, enquanto no ceco-cólon proximal não foi influenciada pelos níveis de concentrado na rações. As taxas de passagem do feno de capim coast-cross no rúmen-retículo e no ceco-cólon proximal não foram influenciadas pelo aumento no nível de concentrado nas rações. A degradação efetiva da MS do farelo de soja não foi influenciada, enquanto a do fubá de milho aumentou e do feno de capim coast-cross reduziu linearmente, respectivamente. A degradação efetiva da PB do farelo de soja e do feno de capim coast-cross não variou, porém a do fubá de milho aumentou linearmente, com o aumento dos níveis de concentrado nas rações.

Comparison of in situ degradation kinetics of lucerne germplasm by ANOVA of non-linear models

The ANOVA of non-linear models was used to evaluate the in situ degradation of five lucerne germplasm grown in the Po Valley of Italy during the growing seasons of 1987–1989. The germplasm included one North American synthetic cultivar, three Italian synthetic cultivars and one local Italian ecotype. The degradation kinetics of dry matter (DM), neutral detergent fibre (NDF), acid detergent fibre (ADF) and cellulose were measured using the nylon bag technique. Forage samples, cut at 10% bloom, were wilted, oven dried, ground (5-mm screen) and incubated for 0, 2, 4, 8, 12, 24, 48, 72, 120 and 168 h in the rumen of two dry Holstein cows fitted with ruminal cannula. The significance of two contrasts was tested: Contrast 1: ecotype versus synthetic cultivars and Contrast 2: North American versus Italian synthetic cultivars. Total DM yield of the ecotype showed no significant difference from the synthetic cultivars, while in Contrast 2, the North American synthetic showed greater DM yield (83.5 vs. 72.5 metric tonnes (MT) ha −1, P < 0.05). Chemical composition data showed the ecotype having greater ( P < 0.10) NDF and cellulose content relative to the synthetic cultivars. The North American synthetic cultivar showed greater ( P < 0.10) crude protein content than the Italian synthetic cultivars. Effective DM degradability, at a ruminal turnover rate of 8% h −1, was higher ( P < 0.05) for the synthetic cultivars (48.6%) compared with the ecotype (46.1%). This advantage for the synthetic cultivars may have resulted from greater content of non-cell-wall constituents and by the presence of cell wall constituents available to ruminal microorganisms. ANOVA of non-linear models showed higher DM and NDF degradability for synthetic cultivars from 0 to 168 h and from 13 to 168 h at P < 0.05, respectively. Therefore, cultivar selection significantly influenced the nutritive properties of lucerne forage. The application of ANOVA of non-linear models for Contrast 2 showed a generally greater ( P < 0.05) availability for the fibre fraction for the North American synthetic cultivar. These important nutritional differences could not have been detected using the traditional statistical analysis of single degradation parameters.