• Energy Research

Three cultivars of Lupinus albus L. (Lutteur, Lublanca and Multitalia) were assessed for proximate composition, fatty acids, alkaloids and in vitro fermentation characteristics over three harvest years.The chemical composition varied greatly during the three harvest years. Crude protein content ranged from 353 to 456 g kg(-1) dry matter (DM), neutral detergent fiber content from 209 to 321 g kg(-1) DM and lignin content from 3.0 to 63.9 g kg(-1) DM. Lublanc showed the highest crude protein (417 g kg(-1) DM) and lignin (35 g kg(-1) DM) contents. High levels of lipids (89.9 g kg(-1) DM) and starch (93.3 g kg(-1) DM) were found in all samples. Alkaloid content ranged from 3.63 to 165 mg per 100 g. Lutteur and Lublanc showed more favorable n-3/n-6 polyunsaturated fatty acid ratios (from 0.44 to 0.73) and lower values of the anti-quality factor 'erucic acid' (from 5.8 to 20.9 g kg(-1) ) than Multitalia. Lutteur showed higher degradability (897 g kg(-1) ), gas production (330 mL g(-1) organic matter (OM)) and volatile fatty acid production (117 mmol g(-1) OM) than the other varieties.The present data suggest L. albus L. cv. Lutteur to be a promising crop as food thanks to its high nutritive traits and most constant yield over time.

SummaryTo find equations able to estimate the fermentation characteristics of the caecum from that of faeces, caecal content and faeces of 10 hybrid Hyla rabbits were used as inocula for an in vitro gas production trial. About 1 g of 12 roughages, 11 hays (ryegrass, alfalfa, sulla, oat, vetch, sulla‐lolium, vetch‐oat, sulla‐oat, clover, ryegrass‐clover, sulla‐vetch‐oat) and a wheat straw, was weighed, in triplicate per inoculum, in 120‐ml flasks; 75 ml of anaerobic medium and 4 ml of reducing solution were added and the flasks were placed at 39 °C. Caecal content and faeces were diluted respectively 1:2 (CI) and 1:8 (FI) with anaerobic medium and were introduced into their respective flasks (10 ml). Gas production was recorded 20 times at 2–24 h intervals throughout fermentation (120 h). The fermentation characteristics (i.e. degraded organic matter, OMd; potential gas production, A; maximum fermentation rate, Rmax; volatile fatty acid, VFA; ammonia, NH3) were studied by inocula and substrates. The two inocula did not differ in OMd but CI produced significantly higher gas (A, 213.1 vs. 199.4 ml/g, respectively, for CI and FI, p < 0.01) in less time (Rmax, 3.08 vs. 2.24 ml/h, respectively, for CI and FI, p < 0.01). CI also produced higher levels of total VFA (57.86 vs. 46.70 mmol/g OM, respectively, for CI and FI, p < 0.01) and showed a higher branched chain proportion (0.023 vs. 0.018, respectively, for CI and FI, p < 0.01). For some parameters (as OMd pH and propionate) the equations for the estimation of caecal fermentation characteristics from that of faeces were accurate (R2 > 0.8828) and reliable (CV < 10.78%) suggesting that faeces can be successfully used for the estimation of these parameters.

AbstractBACKGROUND: The aim of this trial was to evaluate the replacement of rumen fluid with faeces as inoculum in studying the in vitro fermentation characteristics of diets for ruminants using the in vitro gas production technique. Six iso‐protein diets with different forage/concentrate ratios were incubated with rumen fluid (RI) or faeces (FI) collected from sheep.RESULTS: Most of the fermentation parameters were influenced by diet and inoculum (P < 0.01). With both inocula, organic matter degradability (dOM), cumulative gas production (OMCV) and maximum fermentation rate (Rmax) increased as the amount of concentrate in the diet increased. Rmax was lower with FI vs RI (P < 0.01); dOM was higher with FI vs RI and the diet × inoculum interaction was significant. As expected, with both inocula, Rmax increased as the neutral detergent fibre content of the diet decreased. Significant correlations were obtained using both inocula between OMCV/dOM and gas/volatile fatty acid (VFA), while the correlation VFA/dOM was significant only with FI. The microbial biomass yield calculated by stoichiometric analysis for all diets was higher with FI vs RI. With FI the organic matter used for microbial growth showed an overall decreasing trend as the amount of concentrate in the diet increased.CONCLUSION: The results indicate that both faeces and rumen fluid from sheep have the potential to be used as inoculum for the in vitro gas production technique. Copyright © 2011 Society of Chemical Industry

<p><strong>Background.</strong> In sub-Saharan Africa, pasture is the most used practice in ruminant production, and grazing areas characteristics varied in different environment. To improve ruminants’ performances, the quality of forages represents one of the most important factors to keep under control. <strong>Objective.</strong> To quantify the effects of grazing stocking rate on the nutrient composition, energy content and <em>in vitro</em> fermentation characteristics including volatile fatty acids (VFA) and methane production (CH₄) of two local perennial grasses <em>Dactyloctenium aegyptium</em> L. and <em>Leptochloa caerulescens </em>L. <strong>Methodology.</strong> The forage samples were collected in three locations (Zinvié, Gakpé, Adounko) characterized by different stocking rate (low, medium and high). Their chemical composition, energy content and <em>in vitro</em> fermentation characteristics, including CH₄ production, were determined. <strong>Results.</strong> <em>D.</em> <em>aegyptium </em>showed the<em> </em>highest crude protein, energy content, organic matter degradability and VFA production (p&lt;0.01) when collected in Zinvié, whereas the highest (p&lt;0.01) structural carbohydrates (NDF) content was detected in Gakpé area and the highest CH₄ production was recorded from the sample collected in Adounko (p&lt;0.01). Contrariwise, <em>L. caerulescens</em> showed the highest level of crude protein and degradability (p&lt;0.01) when collected in Zinvié, whereas it proved the highest NDF content and the lowest lignin values (p&lt;0.01) when collected in Adounko. The highest CH₄ level was obtained from the sample collected in area of Gakpé (p&lt;0.01). Higher (p&lt;0.01) <em>in vitro</em> VFA production were recorded in samples collected in Adounko and Gakpé than in the Zinvié. <strong>Implications.</strong> The results obtained in this study highlight the significant influence of urbanization and herd concentration, as well as of other environmental conditions, on the nutritional value and potential environmental impact of the studied perennial grasses. <strong>Conclusion.</strong> Samples from high grazing stocking rate locations produced more <em>in vitro</em> methane. Further <em>in vivo</em> studies are needed to confirm these results.</p>