Intake, digestibility, and passage of a commercially designed diet by two Propithecus species.

The digestibility and passage of an experimental diet was used to compare the digestive physiology of two Propithecus species: P. verreauxi and P. tattersalli. Though both animals have a similar feeding ecology, the captive status of P. verreauxi is considered more stable than that of P. tattersalli. The test diet included a local tree species, Rhus copallina, at 15% of dry matter intake (DMI) and Mazuri Leafeater Primate Diet at 85% of DMI. The chemical composition of the diet (dry matter basis) was 25% crude protein, 34% neutral detergent fiber (NDF), and 22% acid detergent fiber (ADF) with a gross energy of 4.52 kcal/g. After a 6 week acclimation to the experimental diet, animals were placed in research caging. After a 7 day adjustment period, animals were dosed with chromium mordant and Co-EDTA as markers for digesta passage and all feed refusals and feces were collected at timed intervals for 7 days. Digestibility values, similar for both species, were approximately 65% for dry matter, crude protein, and energy, and 40% and 35% respectively, for NDF and ADF. Transit times (17-18.5 hr) and mean retention times (31-34 hr) were not significantly different between species, and there was no difference between the chromium mordant and Co-EDTA. Serum values for glucose, urea, and non-esterified fatty acids (NEFA) were obtained during four different time periods to monitor nutritional status. While there was no change in serum glucose, serum urea increased over time. The NEFAs increased across all four time periods for P. verreauxi and increased for the first three periods then decreased in the last period for P. tattersalli. Results obtained indicate no difference in digestibility nor digesta passage between species, and that both Propithecus species were similar to other post-gastric folivores.

Thermogravimetric evaluation of perennial ryegrass (Lolium perenne) for the prediction of in vitro dry matter digestibility

Thermogravimetry (TG) can be used for assessing the compositional differences in grasses that relate to dry matter digestibility (DMD) determined by pepsin-cellulase assay. This investigation developed regression models for predicting DMD of herbage grass during one growing season using TG results. The calibration samples were obtained from a field trial of eight cultivars and two breeding lines. The harvested materials from five cuts were analysed by TG to identify differences in the combustion patterns within the range of 30-600 degrees C. The discrete results including weight loss, peak height, area, temperature, widths and residue of three decomposition peaks were regressed against the measured DMD values of the calibration samples. Similarly, continuous weight loss results of the same samples were also utilised to generate DMD models. The r(2) for validation of the discrete and the best continuous models were 0.90 and 0.95, respectively, and the two calibrations were validated using independent samples from 24 plots from a trial carried out in 2004. The standard error for prediction of the 24 samples by the discrete model (4.14%) was higher than that by the continuous model (2.98%). This study has shown that DMD of grass could be predicted from the TG results. The benefit of thermal analysis is the ability to detect and show changes in composition of cell wall fractions of grasses during different cuts in a year.

The effect of glycerol inclusion on broiler performance and nutrient digestibility

1. Crude glycerol from biodiesel production was offered ad libitum to broiler chickens in a 21-d feeding and digestibility trial. The study was designed as a 3*2+1 factorial design with 3 concentrations (33, 67, 100 g/kg) of glycerol from 2 sources, A and B (PRS Environmental Ltd and John Thompson and Sons Ltd) and a control diet. The diets were formulated to contain apparent metabolisable energy (AME) of 12.95 MJ/kg (assuming 14.6 MJ/kg for glycerol).

The prediction of intake potential and organic matter digestibility of grass silages by near infrared spectroscopy analysis of undried samples

A study was undertaken to examine a range of sample preparation and near infrared reflectance spectroscopy (NIPS) methodologies, using undried samples, for predicting organic matter digestibility (OMD g kg(-1)) and ad libitum intake (g kg(-1) W-0.75) of grass silages. A total of eight sample preparation/NIRS scanning methods were examined involving three extents of silage comminution, two liquid extracts and scanning via either external probe (1100-2200 nm) or internal cell (1100-2500 nm). The spectral data (log 1/R) for each of the eight methods were examined by three regression techniques each with a range of data transformations. The 136 silages used in the study were obtained from farms across Northern Ireland, over a two year period, and had in vivo OMD (sheep) and ad libitum intake (cattle) determined under uniform conditions. In the comparisons of the eight sample preparation/scanning methods, and the differing mathematical treatments of the spectral data, the sample population was divided into calibration (n = 91) and validation (n = 45) sets. The standard error of performance (SEP) on the validation set was used in comparisons of prediction accuracy. Across all 8 sample preparation/scanning methods, the modified partial least squares (MPLS) technique, generally minimized SEP's for both OMD and intake. The accuracy of prediction also increased with degree of comminution of the forage and with scanning by internal cell rather than external probe. The system providing the lowest SEP used the MPLS regression technique on spectra from the finely milled material scanned through the internal cell. This resulted in SEP and R-2 (variance accounted for in validation set) values of 24 (g/kg OM) and 0.88 (OMD) and 5.37 (g/kg W-0.75) and 0.77 (intake) respectively. These data indicate that with appropriate techniques NIRS scanning of undried samples of grass silage can produce predictions of intake and digestibility with accuracies similar to those achieved previously using NIRS with dried samples. (C) 1998 Elsevier Science B.V.

Broiler chicken ileal apparent digestibility of calcium and phosphorus from microalgae spirulina maxima.

2016

Efecto de diferentes concentraciones de Taninos sobre la flora microbiana ruminal y en la degradabilidad in vitro del forraje de alfalfa.

Tesis (Maestría en Ciencias en Producción Animal) UANL

Dinámica estacional del valor nutritivo y cinética ruminal de la planta completa, hojas y tallos del zacate buffel (Cenchrus ciliaris L.) así como los híbridos nueces y llano

Tesis (Maestría en Ciencias con Especialidad en Recursos Alimenticios y Producción Acuícola) UANL

Estimación del valor nutritivo y digestión ruminal de cinco líneas apomíticas y un híbrido de pasto buffel (Cenchrus Ciliaris L.)

Tesis ( Doctorado en Ciencias con Especialidad en Alimentos) UANL

Dinámica estacional del valor nutritivo y digestión ruminal del forraje de 10 arbustivas de Baja California Sur, México

Tesis ( Doctor en Ciencias con Especialidad en Alimentos) U.A.N.L.

Anaerobic Digestibility of Microalgae : Fate and Limitations of Long Chain Fatty Acids in the Biodegradation of Lipids

La digestion anaérobie est un processus biologique dans lequel un consortium microbien complexe fonctionnant en absence d’oxygène transforme la matière organique en biogaz, principalement en méthane et en dioxyde de carbone. Parmi les substrats organiques, les lipides sont les plus productifs de méthane par rapport aux glucides et aux protéines; mais leur dégradation est très difficile, en raison de leur hydrolyse qui peut être l’étape limitante. Les algues peuvent être une source importante pour la production de méthane à cause de leur contenu en lipides potentiellement élevé. L’objectif de cette étude était, par conséquent, d’évaluer la production en méthane des microalgues en utilisant la technique du BMP (Biochemical méthane Potential) et d’identifier les limites de biodégradion des lipides dans la digestion anaérobie. Le plan expérimental a été divisé en plusieurs étapes: 1) Comparer le potentiel énergétique en méthane des macroalgues par rapport aux microalgues. 2) Faire le criblage de différentes espèces de microalgues d’eau douce et marines afin de comparer leur potentiel en méthane. 3) Déterminer l'impact des prétraitements sur la production de méthane de quelques microalgues ciblées. 4) Identifier les limites de biodégradation des lipides algaux dans la digestion anaérobie, en étudiant les étapes limitantes de la cinétique des lipides et de chacun des acides gras à longues chaines. Les résultats ont montré que les microalgues produisent plus de méthane que les macroalgues. Les BMP des microalgues d'eau douce et marines n'ont montré aucune différence en termes de rendement en méthane. Les résultats des prétraitements ont montré que le prétraitement thermique (microonde) semblait être plus efficace que le prétraitement chimique (alcalin). Les tests de contrôle du BMP faits sur l'huile de palme, l’huile de macadamia et l'huile de poisson ont montré que l'hydrolyse des huiles en glycérol et en acides gras à longues chaines n'était pas l'étape limitante dans la production de méthane. L'ajout de gras dans les échantillons de Phaeodactylum dégraissée a augmenté le rendement de méthane et cette augmentation a été corrélée à la quantité de matières grasses ajoutées.

Effets des diètes de remplacement du maïs sur les performances de croissance, le pH ruminal et les paramètres biochimiques sanguins chez les veaux de grains

L’objectif de cette étude a été d’évaluer l’effet du remplacement total ou partiel du maïs d’une ration alimentaire standard (MS) sur les performances de croissance, le pH ruminal et les paramètres biochimiques sanguins chez les veaux de grain de race Holstein. Quatre groupes de 80 veaux ont été répartisen32 parcs (10 veaux/parc) et ont été assignés au hasard à quatre rations alimentaires. Les rations alimentaires ont été: la ration standard qui est constituée de maïs et un supplément protéique à 43,6% de protéine brute (MS);une ration réduite de maïs, avec tourteau de canola et de drèche de distillerie de maïs avec soluble (MCD); une ration réduite de maïs, avec supplément protéique à 43,6% de protéine brute et de drèche de distillerie de maïs avec soluble (MSD); et finalement une ration d’orge roulé, de tourteau de canola et de drèche de distillerie de maïs avec soluble (OCD). Les rations alimentaires ont été formulées selon une phase de démarrage P1 (j0 à j54), une de croissance P2 (j55 à j85) et une de finition P3 (j86 à j96). Un groupe additionnel de 5 veaux contrôle (CT), a reçu une ration alimentaire non acidogène à base de fourrage et de concentré. Notons qu’avant le début des traitements alimentaires au j0, sauf CT, les veaux ont reçu une ration d’adaptation contenant du maïs et de l’orge (50-50) et un supplément protéique pendant 20j. Les gains moyens quotidiens (GMQ) ont été similaires aux périodes P1 (0j-j27, j28-j54) et P2 (j55-j85), mais à la période P3 (j86-j96), le GMQ de la ration OCD a été plus grand que ceux dans les autres rations (p<0.001). Le rendement carcasse des veaux abattus au poids vifs d’environ 267 kg, de la ration OCD a été plus petit que ceux des rations MS et MSD (p<0.002). La matière sèche ingérée (MSI) a diminué pour le groupe MSD au j96, comparée à celles des groupes MS et BCD (p<0.001). Cependant, les rations alimentaires n’ont pas eu d’effet sur le poids vif des veaux. Les durées moyennes en dessous du pH ruminal de 5.6 (DpH5.6 en h.j.-1) du j68 au j85 (P2) ont été similaires pour les groupes CT et OCD (p=0.09) et plus petites (p<0.001) que celles des groupes du MS, MCD et MSD. Pendant la phase P3, les DpH5.6 des groupes de MS, MCD et MSD, ont été similaires (p>0.83), mais plus grandes que celle du groupe de OCD (p<0.0001). Les DpH5.6 n’ont pas eu d’effet sur les GMQ. Aux j68 et j96, les rations alimentaires n’ont pas eu d’effet sur la L-lactate (p > 0.05), le pH sanguin (p > 0.001; non significatif après l’ajustement de Bonferroni :NSAB) et le trou anionique (p > 0.009; NSAB). La PCO2 des animaux du groupe MS a été plus grande que celle du groupe CT (p = 0.0003). Au j68, HCO3 - du groupe CT a été plus grande que celle du groupe MCD (p = 0.0008). Les traitements alimentaires n’ont pas d’effets sur la lipopolysaccharide binding protein (LBP) aux j0 et j68. Au j96, la LBP du groupe CT a été plus petite que celle du groupe MS et MCD (p=0.001). Les diètes n’ont pas d’effets significatifs sur les épithéliums et les lamina propria du rumen (p0>0.37), ainsi que sur les abcès du foie (p=0.80). Le remplacement total du maïs par l’orge roulé, la drêche de distillerie de maïs avec soluble et le tourteau de canola amélioré le GMQ en phase de finition, a amélioré le pH du rumen, le rapprochant du pH ruminal physiologique, n’a pas modifié les paramètres biochimiques sanguins qui ont été mesurés et a diminué le rendement carcasse moyen de 1,1%.

Effects of Different Feeding Regimes on the Digestibility and Faecal Excretion of Nitrogen, Soluble Carbohydrates and Fibre Fractions in Water Buffaloes kept under Subtropical Conditions

In the course of the ‘Livestock Revolution’, extension and intensification of, among others, ruminant livestock production systems are current phenomena, with all their positive and negative side effects. Manure, one of the inevitable secondary products of livestock rearing, is a valuable source of plant nutrients and its skillful recycling to the soil-plant interface is essential for soil fertility, nutrient - and especially phosphorus - uses efficiency and the preservation or re-establishment of environmentally sustainable farming systems, for which organic farming systems are exemplarily. Against this background, the PhD research project presented here, which was embedded in the DFG-funded Research Training Group 1397 ‘Regulation of soil organic matter and nutrient turnover in organic agriculture ’ investigated possibilities to manipulate the diets of water buffalo (Bubalus bubalis L.) so as to produce manure of desired quality for organic vegetable production, without affecting the productivity of the animals used. Consisting of two major parts, the first study (chapter 2) tested the effects of diets differing in their ratios of carbon (C) to nitrogen (N) and of structural to non-structural carbohydrates on the quality of buffalo manure under subtropical conditions in Sohar, Sultanate of Oman. To this end, two trials were conducted with twelve water buffalo heifers each, using a full Latin Square design. One control and four tests diets were examined during three subsequent 7 day experimental periods preceded each by 21 days adaptation. Diets consisted of varying proportions of Rhodes grass hay, soybean meal, wheat bran, maize, dates, and a commercial concentrate to achieve a (1) high C/N and high NDF (neutral detergent fibre)/SC (soluble carbohydrate) ratio (HH), (2) low C/N and low NDF/SC ratio (LL); (3) high C/N and low NDF/SC ratio (HL) and (4) low C/N and high NDF/SC (LH) ratio. Effects of these diets, which were offered at 1.45 times maintenance requirements of metabolizable energy, and of individual diet characteristics, respectively, on the amount and quality of faeces excreted were determined and statistically analysed. The faeces produced from diets HH and LL were further tested in a companion PhD study (Mr. K. Siegfried) concerning their nutrient release in field experiments with radish and cabbage. The second study (chapter 3) focused on the effects of the above-described experimental diets on the rate of passage of feed particles through the gastrointestinal tract of four randomly chosen animals per treatment. To this end, an oral pulse dose of 683 mg fibre particles per kg live weight marked with Ytterbium (Yb; 14.5 mg Yb g-1 organic matter) was dosed at the start of the 7 day experimental period which followed 21 days of adaptation. During the first two days a sample for Yb determination was kept from each faecal excretion, during days 3 – 7 faecal samples were kept from the first morning and the first evening defecation only. Particle passage was modelled using a one-compartment age-dependent Gamma-2 model. In both studies individual feed intake and faecal excretion were quantified throughout the experimental periods and representative samples of feeds and faeces were subjected to proximate analysis following standard protocols. In the first study the organic matter (OM) intake and excretion of LL and LH buffaloes were significantly lower than of HH and HL animals, respectively. Digestibility of N was highest in LH (88%) and lowest in HH (74%). While NDF digestibility was also highest in LH (85%) it was lowest in LL (78%). Faecal N concentration was positively correlated (P≤0.001) with N intake, and was significantly higher in faeces excreted by LL than by HH animals. Concentrations of fibre and starch in faecal OM were positively affected by the respective dietary concentrations, with NDF being highest in HH (77%) and lowest in LL (63%). The faecal C/N ratio was positively related (P≤0.001) to NDF intake; C/N ratios were 12 and 7 for HH and LL (P≤0.001), while values for HL and LH were 11.5 and 10.6 (P>0.05). The results from the second study showed that dietary N concentration was positively affecting faecal N concentration (P≤0.001), while there was a negative correlation with the faecal concentration of NDF (P≤0.05) and the faecal ratios of NDF/N and C/N (P≤0.001). Particle passage through the mixing compartment was lower (P≤0.05) for HL (0.033 h-1) than for LL (0.043 h-1) animals, while values of 0.034 h-1 and 0.038 h-1 were obtained for groups LH and HH. At 55.4 h, total tract mean retention time was significantly (P≤0.05) lower in group LL that in all other groups where these values varied between 71 h (HH) and 79 h (HL); this was probably due to the high dietary N concentration of diet LL which was negatively correlated with time of first marker appearance in faeces (r= 0.84, P≤0.001), while the dietary C concentration was negatively correlated with particle passage through the mixing compartment (r= 0.57, P≤0.05). The results suggest that manure quality of river buffalo heifers can be considerably influenced by diet composition. Despite the reportedly high fibre digestion capacity of buffalo, digestive processes did not suppress the expression of diet characteristics in the faeces. This is important when aiming at producing a specific manure quality for fertilization purposes in (organic) crop cultivation. Although there was a strong correlation between the ingestion and the faecal excretion of nitrogen, the correlation between diet and faecal C/N ratio was weak. To impact on manure mineralization, the dietary NDF and N concentrations seem to be the key control points, but modulating effects are achieved by the inclusion of starch into the diet. Within the boundaries defined by the animals’ metabolic and (re)productive requirements for energy and nutrients, diet formulation may thus take into account the abiotically and biotically determined manure turnover processes in the soil and the nutrient requirements of the crops to which the manure is applied, so as to increase nutrient use efficiency along the continuum of the feed, the animal, the soil and the crop in (organic) farming systems.