The objective of this study was to validate near-infrared reflectance spectroscopy (NIRS) applied to faeces (FNIRS) for estimating the grass in vivo organic matter digestibility (G-OMD) and the grass dry matter intake (G-DMI, kg/d) of concentrate-supplemented grazing dairy cows. The G-OMD estimates from one FNIRS model were compared with two estimates using faecal nitrogen indicator (FNI) methods. Similarly, two FNIRS models were compared with the ratio technique (RT) and with three animal performance methods (APM) for estimating G-DMI. The results were analysed at cow and herd level in two grazed paddocks (P1 and P2) in a rotational grazing scheme.For both G-OMD and G-DMI, the DIMS estimations were correlated (P < 0.05) with other predictive methods (r = 0.61 for G-OMD and r = 0.63-0.88 for G-DMI). Depending on the estimation method, the G-OMD varied from 0.689 (FNIRS) to 0.773 (FNI). The FNI estimates were generally higher and were similar to the G-OMD estimates obtained from NIRS analyses of grass sampled in the field. The FNIRS and FNI estimates were biased at cow and paddock level by 0.01-0.1 digestibility units (P < 0.001).Depending on the estimation method, the G-DMI estimates varied from 11.9 to 16.4 kg/d. FNIRS and APM produced similar estimates of G-DMI at both cow and herd level. The RT estimates of G-DMI were 3 kg/d higher than the FNIRS and APM estimates (P < 0.05). The G-DMI estimated by RT methods was particularly high for P2, with a mean value of 18.5 kg/d, which seemed too high in terms of the maximum intake capacity of supplemented grazing dairy cows.For both G-OMD and G-DMI and for all the estimation methods, inter-cow and intra-paddock variations, expressed through the coefficient of variation (SD/mean), ranged from 0.05 to 0.40. As the accuracy of the FNIRS models, expressed through the standard error of cross validation (SECV), was lower than these inter-animal and intra-paddock variations, we suggest that FNIRS could be used to record, quickly and easily, the evolution of grass digestibility and the intake of grazing dairy cows. These estimates could be implemented through decision-support systems aimed at improving the management of grazing dairy herds. (C) 2012 Elsevier B.V. All rights reserved.

Les caractéristiques de dégradabilité in sacco et les valeurs protéiques de 4 légumineuses fourragères cultivées (Aeschynomene histrix, Stylosanthes fructicosa, Mucuna pruriens var. utilis, Cajanus cajan) ont été étudiées suivant 3 stades de développement (végétatif, floraison, foin). Les fourrages verts ont été récoltés en milieu de croissance végétative et en pleine floraison et les foins de ces espèces en début floraison. Les récoltes ont permis d’obtenir 12 fourrages différents. Les teneurs en MAT sont significativement différentes entre espèces (p < 0,05) et celles-ci n’évoluent pas de façon significative au cours du développement. Les teneurs en lignine (ADL) et en extrait éthéré (EE) varient très significativement entre espèces (p < 0,001). Pour les 4 légumineuses, les foins se différencient des fourrages frais par des teneurs en constituants pariétaux légèrement plus élevées. En ce qui concerne les 3 composantes de la matière sèche (MO : matière organique, MAT : matières azotées totales, NDF : neutral detergent fiber), la fraction soluble (a) et la fraction dégradable (b) ne présentent pas de différences significatives entre espèces et stades de développement (p > 0,05). Pour la composante NDF, la solubilité (a) des fourrages diminue en passant du stade végétatif à la floraison. La vitesse de dégradabilité (c) est plus élevée au stade feuillu chez toutes les espèces. Elle n’apparaît significativement différente (p < 0,05) entre les stades de développement que pour la composante NDF. La dégradabilité théorique des MAT (DTMAT) présente des différences significatives (p < 0,05) aussi bien pour les espèces que pour les stades de développement. La différence entre espèces est principalement liée à l’écart important entre Cajanus cajan et celle des autres légumineuses. La DTMAT du Cajanus cajan est en moyenne de 11 points plus faible que celle des autres espèces. Chez les légumineuses étudiées, les valeurs protéiques digestibles dans l’intestin selon l’azote disponible (PDIN) sont supérieures aux valeurs PDIE (protéines digestibles dans l’intestin selon l’énergie disponible). Aucune de ces deux valeurs PDI n’est influencée significativement par le stade de développement ou l’espèce. Aeschynomene histrix a présenté le meilleur rapport entre PDIN et PDIE. Mucuna pruriens var. utilis avec ces valeurs PDI élevées serait le plus apte à corriger le déficit azoté des graminées fourragères tropicales.Mots clés : Légumineuses, dégradabilité in sacco , valeurs protéiques, Bénin.

The influence of 4 tropical grasses [Panicum maximum, Andropogon gayanus broad-(BL) and narrow-leaf (NL) types and Pennisetum purpureum] and 6 legumes (Aeschynomene histrix, Stylosanthes fruticosa, Centrosema pubescens, Mucuna pruriens var. utilis, Cajanus cajan and Leucaena leucocephala) on fertility of the topsoil in the Sudanian region of Benin over 3 years was investigated. The plants were sown without fertiliser, harvested under a cut-and-carry regime and soil changes were compared with those under a natural fallow. Soil samples were collected before the study commenced and at the end of the 3-year study. These were analysed for pH, organic C, N, available P and exchangeable cations (Ca, Mg, K and Na). N, P and K contents of aerial parts were determined to estimate the exports of these elements. For the grasses, root biomass, depth and distribution were also measured. Three years after grasses and legumes were sown, the pH under the grasses (6.6-6.7) was higher than under the legumes (6.2-6.3) and C and N concentrations had declined from the initial levels. Owing to their deep rooting systems, A. gayanus BL and P. maximum, and probably C. cajan and L. leucocephala, appeared able to recycle nutrients from deeper soil layers. While these species could be used for ley pastures in savannah regions of west Africa, maintenance fertiliser applications would be required to prevent nutrient depletion under a cut-and-carry regime. Further studies to test the efficacy of farmyard manure in providing these nutrients and to examine the growth of the legumes when inoculated with appropriate rhizobia seem warranted.

Le comportement alimentaire et les performances de croissance de 12 moutons de race Djallonké ont été étudiés en pâture, à la ferme expérimentale de l\'Université de Parakou, sur 2 parcelles installées respectivement avec Andropogon gayanus + Aeschynomene histrix (M1) et Panicum maximum var. C1 + Aeschynomene histrix (M2). Les essais ont été effectués en pleine saison des pluies (juillet, août et septembre) et répétés au début de la saison sèche (Octobre et Novembre). La méthode du prélèvement des fourrages à la manière de l\'animal (hand-pluking) a permis d\'estimer l\'ingestion au pâturage. Les échantillons de fourrages ainsi récoltés ont été analysés par la spectrométrie dans le proche infrarouge (SPIR) afin d\'en déterminer la composition chimique. Le recours à des études de fermentescibilité en seringues a permis d\'établir l\'énergie métabolisable. Par la suite, les valeurs énergétiques nettes ont été exprimées en UFL et UFV. Les valeurs protéiques ont été établies dans le système des matières azotées digestibles (MAD). Au pâturage, les proportions du temps consacré durant le jour aux différentes activités ont été réparties comme suit : 64 à 85 % pour le broutage, 3 à 12 % pour la rumination et 11 à 25 % pour le repos. Une différence significative (p < 0,05) a été constatée entre les temps consacrés aux activités de broutage au cours de la matinée et dans la soirée. Le pourcentage du temps consacré au broutage n\'est pas significativement influencé par la saison (p > 0,05). La saison n\'influence pas également la rumination ni le repos lorsque ces moutons broutent le mélange M1. Par contre avec le mélange M2, ceux-ci allongent leur temps de repos les après-midi, particulièrement au début de la saison sèche. Les ingestions volontaires au pâturage ont varié entre 31 et 79 gMS/kgPV. Les valeurs les plus élevées ont été enregistrées en saison des pluies (p < 0,001) et les animaux ont manifesté une nette préférence pour Aeschynomene histrix que pour les 2 graminées. Les valeurs fourragères ont varié entre 0,73 à 0,84 UFV et 0,79 à 0,89 UFL. Les rapports MAD/UF ont oscillé entre 140 et 150 g/kg de MS pour le mélange M1 puis 75 et 140 g/kg de MS pour M2 Ces fourrages en mélange ont permis d\'atteindre des performances de croissance à l\'herbage de 50 g/jour/animalGrazing behaviour and fattening performances of 12 Djallonke sheeps were studied in the experimental farm of the University of Parakou, on two plots pasture containing either Andropogon gayanus + Aeschynomene histrix (M1) or Panicum maximum var. C1 + Aeschynomene histrix (M2). Survey began during the rainy season (July, August and September) and was repeated during the dry season (October and November). Ingestion was measured according to bite count method (hand-pluking). Diet samples were analysed by NIRS system to determine the chemical composition. In vitro gas production allowed the establishment of metabolic energy. Afterwards, net energy values were expressed in French units (UFL and UFV). Proteins values were established in Digestible Crude Protein system (DCP). In the pasture, the proportions of the time used by the various diurnal activities were distributed as follows: 64 to 85 % for grazing, 3 to 12 % per day for the rumination and from 11 to the 25 % per day for the resting time. A clear difference was observed between the periods of time dedicated to grazing activities during the morning and the afternoon. The time percentage devoted to grazing is not significantly influenced by the season (p > 0.05). The season does not influence the rumination or the resting time when the sheep graze a M1 mixture. On the contrary, with the M2 mixture, those sheep rested more in the afternoons, especially at the beginning of the dry season. Voluntary intake varied between 31 and 79 g DM/kg LW. The highest values were registered during the rainy season (p < 0.001) and the animals operated a selection in favour of Aeschynomene histrix with regard to grass. The forage energy concentration varied between 0.73 and 0.84 UFV and between 0.79 and 0.89 UFL. The proportion DCP/UF varied between 140 and 150 g/kg of DM for M1 mixture and between 75 and 140 g/kg of DM for M2. Theses diets allowed achieving forage fattening performances of 50 g/day/animal. Keywords: Comportement alimentaire, Moutons Djallonké, fourrages, performances, Bénin.; Grazing behaviour, Djallonke sheeps, forage, performances, BeninAnnales des Sciences Agronomiques du Bénin Vol. 10 (1) 2008: pp. 31-49

The objective of this study was to evaluate the potential of near infrared reflectance spectroscopy (NIRS), applied to forage and/or faeces, to estimate the in vivo organic matter digestibility (OMD) and the organic matter voluntary intake (OMVI, g/kg metabolic weight [BW0.75]) for a wide range of temperate forages. Two different databases, in terms of forage species and development stages were studied. The first one included two grass species and two forage mixtures for which OMD and OMVI were continuously measured during the grass-growing seasons (spring and summer). The second one contained a large set of grass and legume Species and forage mixtures (142 trials) for which OMD and OMVI were measured.Forage and faeces samples were submitted to MRS analysis and predictive calibrations were developed from forage spectra, faeces spectra, forage and faeces subtracted spectra, and faeces and forage concatenated spectra. Working on faecal spectra (alone or concatenated) enabled us to develop the best calibration equations for both OMD and OMVI estimation. The coefficient of determination (R-2) was greater than 0.8. The standard error of cross validation (SECV) for OMD and OMVI was 0.021 and 4.51 g/kg BW0.75, respectively, and the accuracy was similar to that obtained with other predictive methods. Willi regard to the faecal spectra (second derivative mode), the fat absorbency at wavelengths of 1730, 2310 and 2350nm was higher when the corresponding forage was highly digestible and ingestible.In conclusion, applying NIRS to faeces is a rapid and easy analytical method that could be an interesting tool for managing grazing ruminants and optimising their performance. (C) 2008 Elsevier B.V. All rights reserved.

The inclusion of dietary fiber (DF) in diets has been suggested as a way to reduce NH(3) emission in pig barns because it contributes to a shift in N excretion from urine to feces owing to enhanced bacterial growth in the intestines. This study compared an in vitro method to measure bacterial protein synthesis during fermentation with an in vivo N excretion shift induced by diets differing in DF concentrations and solubility. The first experiment measured the effect of graded concentrations of sugar beet pulp (SBP; 0, 10, 20, and 30%) in corn- and soybean meal-based diets on in vivo N excretion partitioning between the urine and feces. A second experiment investigated the replacement of SBP, rich in soluble DF, with oat hulls (OH), rich in insoluble DF (20:0, 10.5:10.5, and 0:22%, respectively). In parallel, the fermentation characteristics of the dietary carbohydrates not digested in the small intestine were evaluated in an in vitro gas test, based on their incubation with colonic microbiota, using a mineral buffer solution enriched with (15)N. The N originating from the buffer solution incorporated into the bacterial proteins (BNI) was measured when half the final gas volume was produced (8.5 to 14.5 h of fermentation) and after 72 h of fermentation. Short-chain fatty acids were determined in the liquid phase. In the first experiment, the inclusion of SBP linearly decreased urinary N excretion from 0.285 to 0.215 g of N excreted in the urine per gram of N ingested and decreased the urinary-N:fecal-N excretion ratio from 2.171 to 1.177 (P < 0.01). In the second experiment, substituting SBP with OH linearly increased the urinary-N:fecal-N excretion ratio (P = 0.009). Unlike short-chain fatty acid production, BNI was greater at half-time to asymptotic gas production than at 72 h of fermentation. Sugar beet pulp enhanced BNI linearly (P < 0.001), 2.01, 2.06, and 2.35 mg g(-1) of diet with 10, 20, and 30% SBP, respectively, as compared with 1.51 mg for the control diet. The substitution of SBP with OH decreased BNI (P < 0.01). With the exception of final gas production, all in vitro kinetic characteristics and BNI were correlated with in vivo N excretion parameters, and regression equations for the prediction of N excretion pathways from in vitro data were identified. Even if the presence of resistant starch in the diet might alter the composition of the fibrous residue that is fermented, the in vitro method is a possible useful tool for the formulation of diets, reducing the effects of pig production on the environment.

The energy and protein value for Guinea pigs (GP) of 9 forages (7 dicots and 2 grasses) and 5 hay-based diets was determined. The apparent faecal digestibility of dry matter, organic matter, crude protein and energy was measured on GP housed in metabolic cages. The forages and the diets were digested in vitro using pepsin and pancreatin hydrolysis and gas fermentation test to simulate stomach, small intestine and large intestine, respectively. Most of the dicots had high digestible crude protein content (152-201 g/kg DM) and the 2 grasses showed lower values (80-85 g/kg DM). Digestible energy content of the forages ranged between 5.79 to 13.08 MJ/kg DM. None of the forage species or hay-based diets provided sufficient energy to supply the 11.7 MJ/kg metabolic energy requirements. The influence of intestinal fermentation on energy and protein values was highlighted by correlations (P<0.05) between in vivo and in vitro data, including gas fermentation. It is the first time that such relationships are reported in single-stomach animals.

Panicum maximum cv. C1, Andropogon gayanus var. bisquamulatus (broad- and narrow-leaf) and Pennisetum purpureum were compared as ley pastures for 3 consecutive years (2000–2002) in the Borgou region of Benin. Their nutritive value for ruminants was also estimated by calculation, based on their chemical composition. The site was on an infertile soil (N = 0.05%; organic carbon = 0.4%). The rainfall recorded during the humid season in 2000 (March–October) was close to the average for the region (1200 mm). However, dry periods occurred during the rainy seasons in 2001 and 2002. Higher production (P 0.05), while yields of the other two species declined. Higher digestible crude protein concentrations (52–62 g/kg DM) were recorded for P. maximum cv. C1 and A. gayanus broad-leaf type compared with the other grasses. However, all forages were potentially deficient in Na, P, Cu and Zn.

This study examined the effect of a bovine colostrum whey supplementation on growth performance, feed intake, faecal Escherichia coli population and systemic immune response of piglets at weaning. A total of 96 piglets weaned at 26 ± 2 days of age were assigned for 4 weeks to one of the two treatments: (1) the control (commercial diet with bovine milk whey powder) and (2) the colostrum (commercial diet with freeze-dried bovine colostrum whey) treatments. The two supplements were incorporated in the diet at a level of 20 g/kg during the first 2 weeks after weaning and lowered to a level of 10 g/kg for the next 2 weeks. BW and feed intake were measured weekly. Faecal E. coli counts were determined weekly on specific culture media. Blood samples were collected weekly and submitted to a cell counter analyser for their main components (red and white blood cells, platelets) and flow cytometry was used to determine the lymphocyte population (B, T, Th and Tc). Finally, total seric immunoglobulin (IgM, IgG and IgA) concentrations were determined by the ELISA method. During the first week of the trial, the piglets from the colostrum treatment had improved average daily gain (170 g/day v. 81 g/day, P < 0.001), average daily feed intake (346 g/day v. 256 g/day, P = 0.03) and feed efficiency (BW gain/feed intake) (0.48 v. 0.31, P = 0.04). The pigs fed the colostrum treatment had also a 25% increase in circulating IgA (P = 0.03) compared with the control treatment the first week. It is concluded that a distribution of bovine colostrum whey (20 g/kg diet) during the first week post-weaning induces a systemic IgA response and has a beneficial action on growth performances and feed efficiency.

Four herbaceous (Aeschynomene histrix, Stylosanthes fruticosa, Centrosema pubescens and Mucuna pruriens var. utilis) and 2 browse forage legumes (Cajanus cajan and Leucaena leucocephala) were tested in a complete randomised block design (4 replicates) on infertile soils in the Borgou region of Benin over 3 consecutive rainy seasons (2000–2002). Leaf and stem production were measured as well as crude protein, crude fi bre, ash and mineral concentrations in leaves. The number of original plants surviving declined in all species except leucaena as the study progressed. Browse legumes produced more leaf material (including stems < 5 mm in diameter; mean of 4450 kg/ha DM) (P < 0.05) than herbaceous legumes (mean of 2370 kg/ha). While leaf production of leucaena increased with time, that of the remaining species declined as the study progressed. The lowest production (P < 0.05) was recorded for M. pruriens (1480 kg/ha DM). Leaf:stem ratio for the browse legumes (0.35–0.49:1) was lower (P < 0.05) than for the herbaceous legumes (0.87–1.10:1). Leaf material for all species was an acceptable source of crude protein (16–28% DM) to complement available forage on natural pastures and savannahs, especially during the dry season. However, concentrations of sodium and zinc in the material were below recommended levels for ruminant feeding.

Bindelle, J., Ilunga, Y., Delacollette, M., Muland Kayij, M., Umba di M’Balu, J., Kindele, E. and Buldgen, A. Voluntary intake, chemical composition and in vitro digestibility of fresh forages fed to Guinea pigs in periurban rearing systems of Kinshasa (Democratic Republic of Congo). Tropical Animal Health and Production . The daily voluntary intake (DVI) of Guinea pigs (GP) fed 15 fresh forages used in periurban rearing systems of Kinshasa (Democratic Republic of Congo) was investigated. In order to determine the best forages combination for GP diet, DVI was compared to their nutritional value measured in vitro using 1) a pepsin-pancreatin hydrolysis, 2) an gas fermentation test on the hydrolysed residues with an inoculum prepared from GP faeces, and 3) the chemical composition of the offered feeds and the hydrolysis residues. The forages ranking based on the DVI was correlated to the NDF content, but not to their nutritional values determined in vitro . According to their high DVI (from 4.23 to 7.75 g/kg liveweigth), and their valuable in vitro nutritional values (crude protein ranging from 261 to 279 g crude protein kg −1 DM, pepsin-pancreatin digestibilities of the dry matter from 0.55 to 0.59 and final gas production from 170 to 196 l kg −1 DM), Desmodium intortum , Euphorbia heterophylla or Amaranthus hybridu s, can be suggested to the farmers to complement the usual diet distributed to the GP based on Panicum maximum .

Two in vitro experiments were carried out to quantify the incorporation of nitrogen (N) by pig colonic bacteria during the fermentation of dietary fibre, including non-starch polysaccharides and resistant starch. In the first experiment, five purified carbohydrates were used: starch (S), cellulose (C), inulin (I), pectin (P) and xylan (X). In the second experiment, three pepsin-pancreatin hydrolysed ingredients were investigated: potato, sugar-beet pulp and wheat bran. The substrates were incubated in an inoculum, prepared from fresh faeces of sows and a buffer solution providing 15N-labelled NH4Cl. Gas production was monitored. Bacterial N incorporation (BNI) was estimated by measuring the incorporation of 15N in the solid residue at half-time to asymptotic gas production (T/2). The remaining substrate was analysed for sugar content. Short-chain fatty acids (SCFA) were determined in the liquid phase. In the first experiment, the fermentation kinetics differed between the substrates. P, S and I showed higher rates of degradation (P < 0.001), while X and C showed a longer lag time and T/2. The sugar disappearance reached 0.91, 0.90, 0.81, 0.56 and 0.46, respectively, for P, I, S, C and X. Among them, S and I fixed more N per gram substrate (P < 0.05) than C, X and P (22.9 and 23.2 mg fixed N per gram fermented substrate v. 11.3, 12.3 and 9.8, respectively). Production of SCFA was the highest for the substrates with low N fixation: 562 and 565 mg/g fermented substrate for X and C v. 290 to 451 for P, I and S (P < 0.01). In the second experiment, potato and sugar-beet pulp fermented more rapidly than wheat bran (P < 0.001). Substrate disappearance at T/2 varied from 0.17 to 0.50. BNI were 18.3, 17.0 and 10.2 fixed N per gram fermented substrate, for sugar-beet pulp, potato and wheat bran, respectively, but were not statistically different. SCFA productions were the highest with wheat bran (913 mg/g fermented substrate) followed by sugar-beet pulp (641) and potato (556) (P < 0.05). The differences in N uptake by intestinal bacteria are linked to the partitioning of the substrate energy content between bacterial growth and SCFA production. This partitioning varies according to the rate of fermentation and the chemical composition of the substrate, as shown by the regression equation linking BNI to T/2 and SCFA (r2 = 0.91, P < 0.01) and the correlation between BNI and insoluble dietary fibre (r = -0.77, P < 0.05) when pectin was discarded from the database.

Microbial fermentation of non-digestible carbohydrates in the pig's large intestine induces a shift of N excretion from urea in urine to bacterial protein in faeces. Experiments were carried out to measure the mineral N incorporation by the pig intestinal microflora using 5 purified carbohydrates in a gas-test: starch (S), cellulose (C), inulin (1), pectin (P) and xylan (X). Fermentation kinetics was modelled. N source in the buffer solution was replaced by N-15 labelled NH4Cl. The bacterial N fixation was determined at mid-fermentation, measuring 15 N incorporation into the solid phase of the buffer. The bacterial N fixation was higher (P < 0.00 1) with I and S (19.9 and 18.1mg N/g incubated DM), compared to P, C and X (8.7, 5.9 and 5.5 respectively). Inulin and S were fermented also more rapidly, even if (0.081 h(-1)) and C (0.074 h(-1)) showed lower half time fractional rate of degradation than S (0. 153 h(-1)), P (0. 133 h(-1)) and X (0. 104 h(-1)). The insoluble dietary fibre content of the substrates was negatively correlated to bacterial N fixation (r=-0.957, P-0.011). The high crude protein content of P (32.5 mg g(-1)DM) might explain the lower impact of this substrate on bacterial N fixation, despite its rapid fermentation. Beside the proportion of insoluble fibre, the N content and the rate of fermentation seem to be the major factors influencing bacterial protein synthesis. Further studies including ingredients with variable content of indigestible protein and mean retention time in the pig's intestines are necessary. (c) 2007 Elsevier B.V. All rights reserved.

The aim of this study was to evaluate the influence of bovine colostrum supplementation on the immune system of weaned piglets in a context of a full ban of in-feed antibiotics. After weaning at 21 days, 24 outbred piglets were fed with a diet supplemented daily for three weeks with 0, 1 or 5 g of colostrum. Feed intake, growth performance, haematological parameters, and serum and local anti-colostrum immunoglobulin levels were examined. Lymphocytes from the blood, spleen, and gut-associated lymphoid were analysed for phenotype as well as for their ability to produce cytokines. The stimulation index (SI) of mononuclear cells from different organs was obtained after colostral or mitogenic stimulation. Feed intake, growth, and haematological parameters were not significantly affected by colostrum. Total serum IgA levels were increased after colostrum supplementation, with a transient decrease in total IgG. Local anti-colostrum immunization was observed in colostrum-fed piglets. The CD21+/CD3+ cells populations of the ileal Peyer's patch (iPP) were markedly affected. The SI of lymphocyte populations changed significantly whereas, naive blood lymphocytes were not stimulated in vitro in the presence of bovine colostrum, suggesting local anti-colostrum immunization and an absence of direct mitogenic effects of the colostrum. Both Th1 and Th2 cytokine production was present in the different organs of colostrum-fed piglets. Bovine colostrum especially stimulated iPP cells.

The aim of this study was to evaluate the influence of bovine colostrum supplementation on the immune Th1/Th2 response in weaned piglets. After weaning at 21 d, 3 groups of 7 piglets were fed ad libitum with a starter diet and received daily 0, 1 or 5 g of spray-dried bovine colostrum. Spleen and gut-associated lymphoid tissues (GALT): ileal Peyer's patch (iPP), jejunum wall (M) and mesenteric lymph node (MLN)) biopsies were collected on each piglet after 3 wk of treatment and analysed for their cytokine mRNA expression (IL-2, IL-4, IL-10, IL-12 and IFN gamma) by RT-PCR. The supplementation with bovine colostrum induced an increase (P < 0.05) in IL-12 in the JW, in IL-2, IL-10 and IL-12 in the MLN and in IL-4, IL-10 and IL-12 in the iPP. In the latter, bovine colostrum also decreased IFN gamma production (P < 0.01). Finally, no effect of the treatments was recorded in the spleen. These results suggest an immunomodulatory effect of bovine colostrum on the GALT, which responded by producing at different levels both Th1 pro-inflammatory cytokines (IL-2, IFN-gamma and IL-12) and Th2 anti-inflammatory cytokines (IL-4 and IL-10). This Th1 Th2 bipolar response protects the weaned piglets from both allergic (food) and infectious (pathogens) diseases. (c) 2007 Elsevier B.V All rights reserved.

Tree leaf meals (TLM) are increasingly used in the tropics to feed pigs. The nutritive value of the TLM of cocoyam (Xanthosoma saggitifolium), mulberry (Morus alba) and Trichanthera gigantea, their effect on the digestive tract and their fermentation rate in the large intestine, were determined in adult sows given diets containing 150 or 300 g TLM per kg. The TLM contained from 8.5 to 12.0 MJ digestible energy per kg dry matter (DM) and from 60 to 125 g digestible protein per kg DM. The digestibility was not affected (P > 0.05) by their rate of incorporation in the diet. The apparent ileal protein digestibility of the diets containing 300 g TLM per kg was also determined by the slaughtering method. It reached 80% for the basal diet and 54, 70 and 74% for the Trichanthera-, mulberry- and cocoyam-based diets, respectively. No diet effect (P > 0.05) was observed on the weight and length of the gastro-intestinal tract, with the exception of a heavier caecum in sows given the Trichanthera-based diet (P < 0.01). The pH of the gastric fluid of these sows was also higher (P < 0.001). The fermentation of the dietary fibre in the large intestine was evaluated by the gas technique using syringes. The cocoyam leaves presented the highest amount of total gas produced after fibre fermentation (P < 0.001). The ranking order of gas production was identical to that observed for the digestibility coefficients: Trichanthera < mulberry < cocoyam. In conclusion, TLM can represent up to 0.3 of a diet for sows. Their use in sow nutrition may be considered in tropical regions where protein sources are scarce.