Varietal effects of barley carbohydrate composition on digestibility, fermentability and microbial ecophysiology in an in vitro model of the pig gastrointestinal tract.

Carbohydrate (CHO) composition can vary markedly between barley varieties. Their influence on digestibility, intestinal fermentation and microbiota in pigs was studied in vitro. Ten hulless (HLB) and 6 hulled barleys (HB) differing in B-glucan, non-starch polysaccharides (NSP), starch content, and amylose/amylopectin ratio, were hydrolyzed enzymatically and subsequently fermented for 72h. CHO fermentation kinetics were modeled; microbial composition and short-chain fatty acid (SCFA) production were analyzed. In HLB, in vitro DM digestibility was positively correlated to starch and amylopectin content and CP digestibility to amylopectin (P<0.05), whereas both were negatively correlated to insoluble NSP (P<0.05). Rate of fermentation was different (P<0.01) between barley types but not correlated to the CHO composition. However, high B-glucan contents induced faster fermentation (P<0.05, HLB; P<0.10, HB). SCFA molar ratios after fermentation of HLB were higher in propionate and branchedchain fatty acids and lower in acetate compared to HB (P<0.01). With HLB, amylose content was positively correlated to butyrate production and negatively to propionate, which was positively correlated to soluble NSP content (P<0.01). In HB, no correlation between SCFA production and the carbohydrate composition was found. TRFLP analysis revealed that Bacteroides and members of Clostridium cluster XIVa were differentially affected in HLB compared to HB as well as by the type and source of CHO. Microbial profiles were also correlated (P<0.05) to SCFA and fermentation parameters but response differed significantly between HB and HLB. The strongest correlation between CHO structure, microbial abundance and fermentation parameters was evident in HLB. Hulless barleys may offer the greatest opportunity to improve gut health in pigs

Desarrollo de una metodología in vitro para estimar la tasa de fermentación de los forrajes en el intestino grueso del cerdo

La metodología para estimar la tasa de fermentación de los forrajes se desarrolló en dos etapas. La primera, de digestibilidad enzimática, simula la digestión ocurrida en el estómago e intestino delgado, mediante el empleo de pepsina y pancreatina; en esta se determina la digestibilidad de la materia seca. La segunda etapa de fermentación simula la fermentación que ocurre en el intestino grueso utilizando como inóculo heces de cerdo; en esta se determina la cantidad de gas producido durante la fermentación de los forrajes y la degradación de la fibra detergente neutra (FDN). Las dos etapas presentaron buena repetibilidad en el tiempo. Abstract Develop of an in vitro methodology to determine the forages fermentation in to the large intestine. The methodology was developing in two phases. The first phase (enzymatic digestibility) simulates the digestion occurred in the stomach and small intestine, by means of the employment of pepsin and pancreatin; and the digestibility of the dry matter is determined. The second phase (in vitro fermentation) simulates the fermentation that occurs in the large intestine utilizing pig faeces; the quantity of gas produced during the fermentation of the feedstuff is determined and determine the degradation of neutral detergent fiber (NDF). All the phases show a good repeatability throw the time. Key words: digestibility in vitro, pigs, fermentación, forages (Azolla filiculoides, Xanthosoma saggitifolium, Morus alba, Trichanthera gigantea y Salvinia molesta)

Diversidad genética de accesiones de nacedero trichanthera gigantea (humb. and amp; bonpl.) nees, mediante ram’s (random amplified microsatellites)

Con el objeto de estudiar la diversidad genética del árbol forrajero nacedero Trichanthera gigantea (Humb. Bonpl.) Nees, existente en la colección nacional de la Fundación Centro para la Investigación en Sistemas Sostenibles de Producción Agropecuaria (CIPAV) se utilizaron cinco cebadores RAMs en 38 accesiones procedentes de once departamentos de Colombia y dos estados de Venezuela. Se obtuvieron 71 bandas usadas para estimar los parámetros de diversidad genética. Se adaptó un protocolo de extracción de ADN para la especie y se estableció un banco de ADN de las accesiones en la Universidad Nacional de Colombia sede Palmira, para la realización de trabajos futuros. Los resultados indicaron que la colección nacional de nacedero presenta heterogeneidad en sus accesiones, alta diversidad genética y no se encontró relación entre los grupos genéticos formados mediante el análisis molecular y las zonas geográficas de origen.To study the genetic diversity of the national collection of Trichanthera gigantea (Humb. and amp; Bonpl.) Nees from the Foundation Center for Research in Sustainable Systems for Agricultural Production (CIPAV), five primers RAMs were used on 38 accessions from 11 departments of Colombia and two states of Venezuela. A pattern of 71 bands was obtained and used to estimate genetic diversity parameters. A specific protocol for DNA isolation was adapted and a DNA bank was established at the National University of Colombia, Palmira campus for further investigations. The results showed heterogeneity and high genetic diversity in these accessions. No relationship was found among molecular group analysis and the geographical origin zones

2008 Inter-laboratory Comparison Study of a Reference Material for Nutrients in Seawater

Autoclaved natural seawater collected in the North Pacific Ocean was used as a reference material for nutrients in seawater (RMNS) during an inter-laboratory comparison (I/C) study conducted in 2008. This study was a follow-up to previous studies conducted in 2003 and 2006. A set of six samples was distributed to each of 58 laboratories in 15 countries around the globe, and results were returned by 54 of those laboratories (15 countries). The homogeneities of samples used in the 2008 I/C study, based on analyses for three determinants, were improved compared to those of samples used in the 2003 and 2006 I/C studies. Results of these I/C studies indicate that most of the participating laboratories have an analytical technique for nutrients that is sufficient to provide data of high comparability. The differences between reported concentrations from the same laboratories in the 2006 and 2008 I/C studies for the same batch of RMNS indicate that most of the laboratories have been maintaining internal comparability for two years. Thus, with the current high level of performance in the participating laboratories, the use of a common reference material and the adaptation of an internationally accepted nutrient scale system would increase comparability among laboratories worldwide, and the use of a certified reference material would establish traceability. In the 2008 I/C study we observed a problem of non-linearity of the instruments of the participating laboratories similar to that observed among the laboratories in the 2006 I/C study. This problem of non-linearity should be investigated and discussed to improve comparability for the full range of nutrient concentrations. For silicate comparability in particular, we see relatively larger consensus standard deviations than those for nitrate and phosphate

Effect Of Pig Bodyweight On Ileal Amino Acid Endogenous Losses After Ingestion Of A Protein-Free Diet Enriched In Pea Inner Fibre Isolates

The present study was conducted to evaluate whether bodyweight and the micronisation of dietary fibre affect the endogenous nitrogen and amino acid losses (ENL and EAAL) in pigs. The effect of the micronising process was tested by providing pigs with 90 g DM·kg–1 BW0.75 of a N-free diet supplemented with isolated pea inner fibres, presented in native or micronised form and with a water-holding capacity of 12 and 4 g water·g–1 DM, respectively. ENL and EAAL were measured on pigs weighing 24, 62 and 105 kg. In all cases, daily ENL increased linearly (P < 0.05) with BW, for the majority of the AA and total N. As BW increased, daily ENL, total EAAL and the majority of EAAL increased linearly independently of micronisation (P < 0.05). When expressed per kg DMI, total EAAL and the majority of each EAA decreased curvilinearly and reached nadir at around 100 kg BW. For ENL expressed per kg DMI, micronisation resulted in a curvilinear decrease with increasing BW, as compared to a linear decrease for pigs fed the native pea fibre diet (non-micronised). Micronisation of pea inner fibres did not decrease ENL or EAAL daily, except for proline. When the losses were expressed as g·k–1g DMI, micronisation did not decrease ENL but decreased (P < 0.05) endogenous losses for a majority of AA as well as for total AA. The results suggest that small pigs excrete more endogenous N per kg DMI than large pigs and that pea fibre micronisation reduces EAAL but not ENL when expressed per kg DMI

Ileal endogenous nitrogen fosses in pigs: effect of the chemical composition, the processing or the dietary level of pea grain inner fibres.

peer reviewedL'effet de la composition chimique, de la mouture et du taux d'incorporation des fibres internes de la graine de pois dans les aliments sur les pertes iléales endogènes chez le porc a été étudié au cours de trois essais successifs. L'ingestion de fibres et d'amidon de pois ridés a légèrement augmenté les pertes iléales d'acides aminés endogènes par rapport à celle de pois lisses. L'incorporation de fibres micronisées (< 50 μm) dans un régime protéiprive a fait chuter les pertes endogènes de moitié par rapport aux fibres non traitées. La capacité de rétention en eau de ces dernières est beaucoup plus élevée que celles des fibres micronisées (13 vs 4 g eau/kg MS). L'ajout de taux croissants de fibres dans le régime (5, 10, 15, 20 % de fibres brutes, soit 2.5, 5.0, 7.5 et 10 % de fibres AOAC) a accru les pertes iléales de manière proportionnelle. Le flux d'acides aminés totaux estimé pour un ingéré nul en fibres est de 6.47 g/kg MS ingéré et chaque gramme de fibres AOAC ajouté par kg d'aliment augmente les pertes totales d'acides aminés endogènes de 0,04 g.The effect of the chemical composition, the grinding or the dietary level of the pea grain inner fibres on the ileal endogenous nitrogen losses in pigs was studied in three experiments. The intake of wrinkled pea inner fibres and starch slightly increased the ileal endogenous amino acid losses compared to smooth peas. The addition of micronized fibres (< 50 μm) in N-free diets significantly decreased the endogenous losses compared to untreated fibres. The water-holding capacity of the latter was higher than that of the micronized fibres (13 vs 4 g water/kg DM). The addition of increasing levels of fibres in diets (5, 10, 15, 20 % raw fibres, i.e. 2.5, 5.0, 7.5, 10 % AOAC fibres) proportionally increased the endogenous losses. The flow of total amino acids estimated for a diet free of fibres reached 6.47 g/kg DM intake and each gramme of AOAC fibre added per kg diet increased the total endogenous amino acid losses of 0.04 g

Effect of dietary proteins and fibres on the ileal endogenous amino acid losses in pigs.

An N-free diet was supplemented with limited but increasing amounts of proteins (30, 60, 90 g/kg diet from a mixture of casein and egg yolk), in order to measure their effect on the ileal endogenous amino acid (AA) losses in pigs. The study was conducted at 2 dietary fibre levels: 20 and 80 g/kg, isolated from pea seeds. Compared to the N-free diet, a supply of 30 g proteins was sufficient to obtain a positive N retention and the following supplies allowed a constant and linear increase (0.88 g N retained/g N intake). The same supply induced an increase in ileal endogenous losses, compared to the control (10.7 vs 7.2 g AA/kg DMi for the low fibre diet) but the difference was not significant because of a high variability between the pigs. The supplies of 60 and 90 g proteins did not modify the level of the losses either: 10.2 and 10.6 g AA/kg DMi, respectively. The same trends were observed for the diets with a high fibre level but, in this case, the losses were significantly higher: respectively 14.9, 16.7, 15.7 and 17 g AA/kg DMi. On the other hand, the fraction of the digesta containing the free AA and the small peptides (< 3 kDa), supposed to be mainly of dietary origin, remained independent of the protein level. This suggests a virtually complete digestibility of the dietary proteins. Thus, pea fibres induce a significant increase of the ileal endogenous losses but without disturbing the protein digestion process, as suggested by the N retention. The protein supply probably increased the digestive secretions but the latter could have been highly reabsorbed, due to a lack in dietary factors susceptible to increase the reabsorption.Un régime protéiprive a été supplémenté en quantités limitées mais croissantes de protéines (30, 60 ou 90 g/kg d’aliment d’un mélange caséine-jaune d’oeuf) afin de mesurer leur effet sur les pertes d’acides aminés (AA) endogènes à l’iléon des porcs. L’étude a été menée à deux niveaux de fibres alimentaires: 20 et 80 g/kg, isolées de graines de pois. Par rapport au régime protéiprive, un ajout de 30 g de protéines a suffi à rétablir une rétention azotée positive et les ajouts suivants ont assuré une augmentation constante et linéaire (0.88 g N retenu/g N ingéré). Ce même ajout a causé une élévation des pertes iléales endogènes par rapport au témoin (10.7 vs 7.2 g AA/kg MS ingéré pour le régime contenant 20 g de fibres) mais la différence n’est pas significative en raison d’une grande variabilité entre animaux. Les apports de 60 et 90 g de protéines n’ont plus modifié le niveau des pertes: 10.2 et 10.6 g AA/kg MSi, respectivement. La même tendance a été observée avec les régimes riches en fibres mais, dans ce cas, les pertes étaient nettement plus élevées: 14.9, 16.7, 15.7 et 17.0 g AA/kg MSi, respectivement. Par ailleurs, la fraction des AA libres et petits peptides (< 3 kDa) des digesta est demeurée indépendante du taux protéique alors qu’elle est supposée contenir les molécules alimentaires indigestibles. Ceci suggère une digestibilité virtuellement complète des protéines alimentaires. Les fibres de pois induisent donc un accroissement significatif des pertes iléales endogènes mais sans entraver la digestion des protéines, comme l’atteste la rétention azotée. L’ajout de protéines a vraisemblablement accru les sécrétions digestives mais celles-ci auront été en grande partie réabsorbées en raison de l’absence de facteurs alimentaires susceptibles d’entraver la réabsorption