EFFECT OF THE NATURE OF THE FEEDING RESOURCE ON ITS IN VITRO GAS PRODUCTION KINETICS USING RUMEN FLUID OF SLAUGHTERED DROMEDARY

Degradation aspects in terms of kinetics of the tested samples namely  dates, oranges and olive residues by the dromedary ruminal microflora is comparatively studied with vetch-oat hay as a standard. The results indicate greater hydrolytic ac-tivity of the dromedary ruminal microflora towards dates and orange residues than both olive residues and hay.  Fermentation of dates and orange residues reaches their stationary phase after 24 hours and olive wastes after 48 hours. However, fermentation process was marked by two phase; namely the degradation of soluble fraction and that of cellulosic one. The results showed also that types of substrate is a determining factor for in vitro gas production. In fact, substrate rich in cellular content (dates and orange residues) is characterised by a fast fermentation that moves towards CO2 production, and it is marked by a long latency phase. On contrary,  the fibrous substrate degradation (olive residues and hay) is tributary of less long latency period and generates CH4. The degradation level observed indicates that the dates and oranges residues might represent an acceptable source of energy for dromedary. On the other hand, the olive residues, in spite of being rich in organic matter, cannot be used in animal feeding

Effects of secondary compounds from cactus and acacias trees on rumen microbial profile changes performed by Real-Time PCR

Plant rich secondary compounds had antimicrobial effects by acting against different rumen microbial populations. The current study investigated the influence of spineless cactus (Opuntia ficus indica f. inermis), Acacia nilotica and A. saligna on rumen microbial fermentation, using in vitro gas production technique, and microbial population profile changes, using a molecular-based technique (Real-Time PCR). The acacias and Opuntia reduced significantly total gas production (p<0.01), rumen CH4 production (p?0.01) and ammonia concentration (p<0.001). At 24h of incubation, Fungi population was 0.30- and 0.03 -fold reduced with A.nilotica and Opuntia as compared to 0h, but 2-and 1.24- fold higher with A.cyanophylla .Increases in the abundance of F.succinogenes were observed in all substrates; however, the tanniferous plants and Opuntia reduced the relative abundance of R.flavefaciens. Methanogenic population was increased with all substrates, except for Opuntia (0. 90- fold lower than the control). There was a significant reduction (p<0.05) in rumen protozoa count with A.cyanophylla, Opuntia and A.nilotica (3.68; 5.59 and 5.34 times, respectively). Results suggested that tannin sources from A.nilotica and A.cyanophylla had an indirect effect on methanogenesis. This study showed an antimicrobial activity of oxalates content of O. ficus indica

Composición química y digestibilidad de varias especies arbustivas características de pastizales en zonas áridas de Argelia

Many wild browse and bush species are undervalued mainly because of insufficient knowledge about their potential feeding value. The objective was to evaluate some nutritional attributes of various Algerian browse and shub species (Atriplex halimus, Artemisia campestris, Artemisia herba-alba, Astragalus gombiformis, Calobota saharae, Retama raetam, Stipagrostis pungens, Lygeum spartum and Stipa tenacissima). Chemical composition, phenols and tannins concentration, in vitro digestibility, in vitro gas production kinetics and in vitro bio-assay for assessment of tannins using buffered rumen fluid, and in situ disappearence of the edible parts of the plants (leaves, thin twigs and flowers) were determined. In general, protein content in dicotyledon species was always greater than in monocotyledon grasses, these showing higher neutral and acid detergent fibre and lower lignin contents than dicots. The tannin concentrations varied considerably between species, but in general the plants investigated in this study had low tannin contents (except for Artemisia spp. and S. tenacissima). Monocots showed lower in vitro and in situ digestibilities, fermentation rate, cumulative gas production and extent of degradation than dicot species. The plants were clustered by principal components analysis in two groups: poor-quality grasses and the most digestible dicot species. Chemical composition (neutral detergent fibre and protein) and digestibility were the main influential variables determining the ranking. In conclusion, A. halimus, A. campestris, A. herba-alba and A. gombiformis can be considered of greater nutritional value than the highly fibrous and low digestible grasses (S. pungens, L. spartum and S. tenacissima) that should be considered emergency roughages.El objetivo de este trabajo fue el de evaluar varias especies arbustivas de Argelia (Atriplex halimus, Artemisia campestris, Artemisia herba-alba, Astragalus gombiformis, Calobota saharae, Retama raetam, Stipagrostis pungens, Lygeum spartum y Stipa tenacissima). Se determinó la composición química, la concentración de fenoles y taninos, la producción de gas y digestibilidad in vitro y la degradabilidad in situ de la parte comestible del pasto arbustivo (hojas, tallos finos y flores). Los contenidos en proteína y lignina fueron superiores en las dicotiledóneas que en las monocotiledóneas, mientras que los contenidos en fibra fueron más elevados en las monocotiledóneas. La concentración en taninos fue variable entre especies y, excepto para Artemisia spp. y S. tenacissima, los contenidos de estos compuestos fueron exiguos en la mayoría de las especies. Las monocotiledóneas fueron menos digestibles, con menores valores de ritmo de fermentación, producción de gas y degradabilidad ruminal. A partir de un análisis de componentes principales se observaron dos agrupaciones de las plantas: en un grupo las monocotiledóneas de baja calidad nutritiva y en otro grupo las dicotiledóneas más digestibles. Este agrupamiento fue determinado fundamentalmente por la composición química (fibra y proteína) y la digestibilidad. En conclusión, A. halimus, A. campestris, A. herba-alba y A. gombiformis pueden ser consideradas de mejor calidad (considerando su composición y digestibilidad), mientras que S. pungens, L. spartum y S. tenacissima podrían considerarse como recursos de baja calidad que sólo serían utilizados cuando no hay disponibilidad de otros alimentos

Methane production from the rumen fermentation of Algerian Acacia tree foliage. Forage resources and ecosystem services provided by Mountain and Mediterranean grasslands and rangelands

4 páginas, 1 tabla.The present study was carried out to determine the in vitro methane production from the rumen fermentation of Acacia tree leaves (Acacia nilotica, A. cyanophylla, A. albida, A. horrida and Albizia julibrissin) and its reduction by the addition of a tannin-blocking agent (polyethylene glycol, PEG). Gas production was determined when foliage from the five plant species was incubated in diluted rumen fluid for 6, 12, 24 and 48 h, and methane was measured after the incubation at 24 h. The incubations were conducted either without or with the addition of the tannin binder polyethylene glycol (PEG-6000). This has been considered a bioassay of tannin activity, represented by the increase in gas (methane) production upon the addition of PEG (i.e., when tanning are neutralized). The ratio +PEG/-PEG (in total gas production) was highest for A. nilotica (2.23 and 1.75 at 12 h and 24h), followed by A. cyanophylla (1.73 at 48 h), reflecting the high amount and biologi - cal activity of tannins in these plants. PEG addition increased methane production for all the Acacia species, thus confirming that tannins in these samples affected methanogenesis. An increase in total volatile fatty acid concentration in samples with addition of PEG was observed only with A. nilotica and A. cyanophylla. Tannins contained in these plants could be of interest to reduce methane production, providing that other parameters of ruminal fermentation were not inhibited.Peer Reviewe

Evaluation of Carob (Ceratonia siliqua) and Honey Locust (Gleditsia triacanthos) Pods as a Feed for Sheep

10 páginas, 4 tablas, 2 figuras.The nutritive value of Ceratonia siliqua and Gleditsia triacanthos pods was determined on the basis of their chemical composition, in vitro gas production and rumen fermentation end-products. Medicago sativa was used as a reference feed material. The studied samples showed differences in chemical composition and phenolic compounds. Crude protein (CP) content was particulary low (80 g/kg DM) in carob and higher in Medicago sativa and G. triacanthos pods with (159.79 and 121.56 g/kg DM, respectively). Inclusion of Polyethylene glycol (PEG) in fermentation medium results in a significant increase (P<0.05) of gas production in Ceratonia siliqua and Gleditsia triacanthos and no effect was observed with M. sativa. The highest values of gas production were observed for C. siliqua and G. triacanthos, whereas Medicago sativa had significantly low values. The highest asymptotic gas production was observed in Ceratonia siliqua and Gleditsia triacanthos (296.80 and 289.55 mL g(-1) DM, respectively), whereas Medicago sativa recorded the lowest value (243.64 mL g(-1) DM). The concentration of acetate differentiated two groups: Medicago sativa and Gleditsia triacanthos (86.58 and 66.32% respectively), while the fermentation of Ceratonia siliqua resulted in a lower acetate concentration (59.84%). Although there were noticeable differences among the three studied samples, Ceratonia siliqua and Gleditsia triacanthos pods showed better nutritional quality, indicating that they could be considered promising and interesting sources of feed for sheep during the dry season or as supplement to low quality diets.Financial support received from the Junta de Castilla y Leon, Spain is gratefully acknowledged. Medjekal S. gratefully acknowledge the receipt of a Study and Doctoral Research Abroad Fellowship funded by the Algerian Ministry of Higher Education and Scientific Research to conduct the experimental work of his PhD projects at the University of Leon (Spain).Peer reviewe

Volatile fatty acids and methane production from browse species of Algerian arid and semi-arid areas

7 páginas, 1 figura, 2 tablas.The objective of the study was to determine the in vitro rumen fermentation end-products of 10 browse species. Serum bottles containing 500 mg of substrate, 10 ml of sheep rumen fluid and 40 ml of buffered medium were incubated for 24 h. After incubation, pH, methane and volatile fatty acid (VFA) productions were recorded. There were differences among feedstuffs (p < .05) in pH and VFA production. Astragalus gombo resulted in the highest and Stipa tenacissima in the lowest VFA production. Gas production was highest for Medicago sativa and lowest for S. tenacissima. Methane production (ml/g DM incubated) varied greatly. The lowest methane production was for S. tenacissima and Arthrocnemum macrostachyum (11.4 and 11.5 ml/g DM, respectively) and the highest for M. sativa and A. gombo (25.8 and 22.7 ml/g DM, respectively). The differences among species shrank when methane was expressed per ml of total gas produced or per mol of VFA produced. This indicates that a lower methane production would be due to a low fermentability of the substrate incubated, rather than to a specific inhibitory effect on methanogenesis. Hence, the 10 browse species studied herein would show little potential for mitigating ruminal methane production.Peer reviewe

Rôle du lactose dans la formation d'entérocolite ulcéronécrosante (ecun) expérimentale chez la caille gnotoxénique monoassociée à des souches de Clostridium butyricum d'origine humaine

International audienc

Valeur nutritive du feuillage de quelques Acacia prépondérants des régions arides et semi-arides d'Algérie

6 páginas, 3 tablas.--Contributed to: 14th International Seminar of the Sub-Network on Nutrition of the FAO-CIHEAM Inter-Regional Cooperative Research and Development Network on Sheep and Goats, "Feeding and management strategies to improve livestock productivity, welfare and product quality under climate change", jointly organized by INRAT and IAMZ-CIHEAM in collaboration with FAO the OEP of Tunisia, IRESA, and the LowInputBreeds project. Hammamet (Tunisia), 15-17 June 2012.Peer reviewe