Improving utilization of crop residues. Evaluation of two chemicals used to improve digestibility of crop residues

Two chemical treatments involving chelating metal caustic swelling (CMCS) and sodium hydroxide (NaOH) were evaluated for their ability to affect in vitro dry matter and in vitro cellulose disappearance (IVDMD and IVCD, respectively), dry matter disappearance in sacco and the chemical composition of two low-quality crop residues, cornstalks (CS) and soya bean residue (SBR). At $\text{chemical}\text{substrate}$ ratios ranging from 0.25:1 to 5:1, linear increases in IVCD of both roughages were noted. Improvements in IVCD of CS and SBR were noted at 1:1, 3:1 and 5:1$\text{chemical}\text{substrate}$ ratios, regardless of whether the treated roughages were used immediately after treatment (fresh basis) or preserved by drying or freezing. Decreased concentrations of neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL) and crude protein (CP) resulted from chemical treatment. No effects of the water component of the solvent solutions were observed. Dry matter disappearance in sacco of CMCS- and NaOH-treated roughages was increased at all $\text{chemical}\text{substrate}$ ratios tested. Treatment of either roughage with CMCS resulted in greater digestibility in sacco than did treatment with NaOH. Treatment of CS with CMCS resulted in higher rates of digestion than did treatment with NaOH. No differences in rates of digestion of SBR were noted between chemicals. Both chemicals were more effective in improving digestibility of CS than of SBR.     

In vitro studies and short-term feeding trial in lambs to evaluate plantain sheath (Musa sapientum) as a feed for ruminants

Plantain sheath (Musa sapientum) contained 6.4% dry matter and 3.4% crude protein, 31.4% crude fibre, 34.6% cellulose, 15.5% hemicellulose and 6% lignin in dry matter.

Digestibility in vitro studies with fistulated bucks revealed a dry matter disappearance of 53.3% after 24 h incubation. The digestibility of neutral detergent fibre (NDF), acid detergent fibre (ADF) and cellulose after 24 h fermentation was 32.2, 21.5 and 30.3%, respectively. After 48 h fermentation, the dry matter digestibility increased to 63.4%, NDF to 47.0%, ADF to 32.2% and cellulose to 42.3%.

A 45-day feeding trial was conducted with 16 crossbred lambs. Plantain sheath replaced paragrass hay dry matter at 32.6, 54.7 and 76.6% levels. Dried plantain sheath, which contributed 14.1, 25 and 34.5% of total dry matter intake, helped a daily gain of 31.1, 28.9 and 37.8 g when fed mixed with concentrate feed.     

Soybean milk residue ensiled with peanut hulls: fermentation acids, cell wall composition, and silage utilization by mixed ruminal microorganisms

Preservation of soybean milk residue (SMR) by ensiling with peanut hulls (PEH) and subsequent utilization of silage by mixed ruminal microorganisms were investigated. Treatments were combinations of SMR with PEH at the following ratios: 100:0, 78:22, 71:29, and 60:40 (fresh weight basis). After eight weeks of ensiling, silage lactic acid, crude protein, ether extract, and non-fiber carbohydrates were highest when SMR was ensiled alone and reduced as amounts of SMR decreased. Similar trends were observed for silage in vitro dry matter digestibility, and gas and volatile fatty acid production by ruminal microorganisms. Conversely, silage pH, dry matter, neutral detergent fiber, acid detergent fiber, cellulose, and lignin increased accordingly. The ensiling treatment appeared to alter silage cell wall composition. In particular, silage treated with PEH at the low level (78:22) resulted in reduced fiber contents and lignification. The silage (SMR:PEH=78:22) had enhanced efficiency of both silage fermentation and in vitro ruminal fermentation pattern.     

Food plant selection by reindeer during winter in relation to plant quality

The relative palatabilities of nine plant taxa used as winter food by reindeer were estimated by presenting them in cafeteria and pairwise tests Feeding p reference indices were then related to the chemical composition of the plants High preference indices were obtained for the lichens Bryoria spp, Cladina arbuscula, C rangiferina and C stellaris, while low values were obtained for the moss Pleurozium schrebel and the dwarf shrubs Empetrum hermaphroditum and Vaccinium myrttllus The grass Deschampsia flexuosa and the lichen Stereocaulon paschale received intermediate scores Feeding preferences showed a strong negative correlation with acid detergent fiber (ADF)-values No statistically significant correlations were found between feeding preferences and contents of nitrogen, in vitro organic matter digestibility (IVOMD) or neutral detergent fiber (NDF)     

Dietary fibre components and pectin chemical features of peels during ripening in banana and plantain varieties

The effects of the ripeness stage of banana (Musa AAA) and plantain (Musa AAB) peels on neutral detergent fibre, acid detergent fibre, cellulose, hemicelluloses, lignin, pectin contents, and pectin chemical features were studied. Plantain peels contained a higher amount of lignin but had a lower hemicellulose content than banana peels. A sequential extraction of pectins showed that acid extraction was the most efficient to isolate banana peel pectins, whereas an ammonium oxalate extraction was more appropriate for plantain peels. In all the stages of maturation, the pectin content in banana peels was higher compared to plantain peels. Moreover, the galacturonic acid and methoxy group contents in banana peels were higher than in plantain peels. The average molecular weights of the extracted pectins were in the range of 132.6-573.8 kDa and were not dependant on peel variety, while the stage of maturation did not affect the dietary fibre yields and the composition in pectic polysaccharides in a consistent manner. This study has showed that banana peels are a potential source of dietary fibres and pectins.     

Effect of high-pressure steam treatment on chemical composition and digestibility in vitro of roughages

Effect of high-pressure steam (5, 7 and 9 kg cm^?2 for 30 and 60 min) on chemical composition and digestibility in vitro of sugarcane bagasse, paddy straw and sorghum straw was studied. The treatment brought about significant falls in the neutral detergent fibre (NDF), specifically the hemicellulose content, and in pH. Soluble carbohydrates and volatile acids (VA) increased with treatment, while acid detergent fibre (ADF) remained constant. The increments in true dry-matter digestibility in vitro (IVTDMD) compared to untreated were 23–64% (sugarcane bagasse), 19–36% (paddy straw) and 31–42% (sorghum straw) with increasing steam pressures and period. The digestibility of cell-wall constituents (CWC) improved with steam treatment in all three roughages. The dry-matter losses resulting from the treatment were 0.9–20%, 17–39% and 1–22% for sugarcane bagasse, paddy straw and sorghum straw, respectively.     

Biodegradation of tannins in oak (Quercus incana) leaves by Sporotrichum pulverulentum

Fermentation of oak leaves with Sporotrichum pulverulentum decreased the contents of total phenols and condensed tannins by 58 and 66% respectively in 10 d. The protein precipitation capacity decreased by 65%. Further increase of fermentation time up to 40 d did not increase substantially, the tannin degradation. Following fermentation, neutral detergent fibre, acid detergent fibre, hemicellulose, cellulose and lignin decreased by 12–16%, 8–10%, 31–51%, 0.3-3% and 14–15% respectively. The loss in dry matter was from 17–21%. The in sacco dry matter digestibility of the fermented leaves was 17% compared to 27% for the unfermented leaves.     

Digestibility of a high-fiber biscuit-based diet by black and white colobus (Colobus guereza)

The acceptability and digestibility of a high-fiber biscuit-based diet was investigated using two adult male Colobus guereza animals. Although the animals were initially reluctant to accept the biscuit, it was eventually readily consumed. Apparent digestion coefficients for the diet (average composition, dry matter basis: 16% crude protein, 25% neutral detergent fiber (NDF), 9.5% acid detergent fiber (ADF), 1.2% acid lignin) determined by total fecal collection were 0.871 for dry matter, 0.813 for NDF, 0.693 for ADF, and 0.208 for acid lignin. Fiber digestive capabilities in C. guereza generally exceeded those reported in ruminant species based on predictive equations. Use of acid lignin and Cr₂O₃ as markers underestimated dry matter digestibility by 3.9 and 6.0%, respectively.     

Effect of feeding yeast culture (Yea-sacc1026) on rumen fermentation in vitro and production performance in crossbred dairy cows

The effect of supplementing diet with yeast culture (Yea-sacc¹⁰²⁶) on dairy cattle was studied by rumen in vitro studies and a feeding trial. Using rumen inoculum from a cow, yeast adapted (YA) and yeast unadapted (YU), incubations were carried out with finger millet (Eleusine coracana) straw (FMS) and a commercial cattle feed (CCF). The 24 h cumulative gas production and digestibility of neutral detergent fibre and acid detergent fibre were not different with YU and YA rumen inoculum for both FMS and CCF. Microbial nitrogen synthesis (mg N ml⁻¹ gas produced) with rumen inoculum from YA feeding regime was higher (P < 0.01) than YU with starch (0.1068 vs. 0.1008) and cellulose (0.0900 vs. 0.0859).A feeding trial was conducted using twelve multiparous cows in midlactation in a switch over design. The cows were divided into two groups of six cows in each group. The duration of the trial was fourteen weeks, each period lasting for 7 weeks. There were no differences in dry matter intake, body weight gain and milk yield. Milk composition for the two groups were also similar.     

Suitability of cell-wall constituents as predictors of organic matter digestibility in some tropical and subtropical by-products

The van Soest detergent method for determination of cell wall constituents is suggested as a good routine analysis for plant material of high fibre content. The chemical composition of the fibre fraction of 24 tropical and subtropical by-products has been investigated, and simple and multiple correlation coefficients have been calculated between organic matter digestibility in vivo and in vitro, and the contents of different cell wall fractions.The acid detergent fibre (ADF) gave the highest negative correlation with the digestibility of organic material independent from the botanical origin of the sample. The ADF fraction proved superior to the Weende crude fibre as well as to single fractions of the cell walls such as lignin, cutin and silica.The determination of ADF is more convenient, and needs only half the time and half the expenditure required for the Weende crude fibre analysis. There is the additional aspect of health: determination of ADF in the detergent analysis requires no use of asbestos.     

Processing and nutritive evaluation of broiler litter as livestock feed

Broiler litter was deep stacked at 30 and 40% moisture or ensiled at 40% moisture for 6 weeks in quadruplicate and subsequently evaluated for changes in chemical composition, pathogenic microbial load and in vitro dry matter degradability (IVDMD). A metabolism trial was conducted with lambs, in which a low-protein basal diet supplemented with litter, deep stacked at 30% and 40% moisture for 6 weeks or ensiled were compared with an isocaloric, isonitrogenous soybean meal supplemented diet. The maximum stack temperature of 65°C (irrespective of moisture level) was attained on day 7 at 45 cm depth and 60.5°C on day 10 at 80 cm depth, which eliminated coliforms. Increases in lactic and acetic acids were recorded with increase in moisture levels and advancement of stacking period. A small increase in crude protein (CP) content was associated with considerable declines in organic matter (OM), cellulose, neutral detergent fiber (NDF) and hemicellulose in deep-stacked litters. The apparent digestibility of nutrients and N-retention in the litter-supplemented diets were similar to those of the soybean meal supplemented diet. It is concluded that by deep stacking at 30 or 40% moisture, or ensiling, the litter was rendered free of pathogens and could be incorporated in the diet of livestock without adversely affecting digestibility of fiber and efficiency of N utilization.     

In vitro degradation of cell-wall and digestibility of cereal straws treated with anaerobic ruminal fungi

Ruminal fungal isolates (Orpinomyces sp.; C-14, Piromyces sp.; C-15, Orpinomyces sp.; B-13 and Anaeromyces sp.; B-6), were evaluated under anoxic conditions for their effect on in vitro dry matter digestibility, neutral detergent fibre, acid detergent fibre and acid detergent lignin using rice and wheat straw as substrate. There was no significant effect of the fungal isolates on the disappearance of the substrates along with rumen liquor when compared to control. The doses of 10(6) cfu/ml of the isolate were found to have maximum degradation of straws in comparison to the doses of 10(3) cfu/ml.     

The effects of sulphur supplementation on cellulose digestion in vitro and on nutrient digestion,nitrogen metabolism and rumen characteristics of lambs fed on good quality fescue and tropical star grass hays

Experiments were conducted in vitro and in vivo to determine the effects of sulphur (S) supplementation of a good quality fescue hay containing 0.27% total S and a tropical star grass hay containing 0.20% total S. Addition of S was on an isosulphurous basis of either sodium sulphate or D,L-methionine. Cellulose digestion in vitro was improved (P < 0.001) by the addition of 1% urea. Supplementation of forage with 0.05, 0.10 or 0.15% S from either sodium sulphate or methionine also stimulated cellulose digestion in vitro. There were no differences between S sources. The addition of 0.4 or 0.8% nitrate-nitrogen (nitrate-N) (potassium nitrate) depressed (P < 0.05) cellulose digestion in vitro of both hays. No effect of animal adaptation to nitrate was evident. Addition of S partially counteracted the depression in cellulose digestion due to nitrate. Trials were conducted in vivo in which 12 crossbred wether lambs (fescue experiment) or 12 crossbred intact male lambs (star grass experiment) were randomly assigned to one of three treatments: control (forage with no addition of S); forage plus 0.15% S as sodium sulphate; and forage plus 0.15% S as D,L-methionine. Lambs were housed in metabolism crates and each experiment was replicated twice. Dry matter intakes were highest for methionine-supplemented fescue and for S-supplemented star grass, regardless of S source. Dry matter digestibility tended to increase with S addition (fescue experiment) and was significantly higher for S-supplemented star grass. There was a significant increase (P < 0.05) in neutral detergent fibre (NDF) and acid detergent fibre (ADF) digestibility due to supplemental S, regardless of S source. Nitrogen retention, ammonia-N and ruminal volatile fatty acids were unaffected by S supplementation.     

Effect of storage and processing of barley on its utilization by pigs and rats

Grain of 16.7% moisture content was stored in exprimental silos by four methods. These were: (1) controlled environment (a sealed container); (2) addition of 1% acid mixture (60 acetic acid: 40 propionic acid); (3) addition of 3.2% sodium hydroxide in a 32% solution to give 21.8% moisture content; and (4) air-dried (82°C) to 13.3% moisture.After 9 months storage, apparent digestibility of dry matter, nitrogen and neutral detergent fibre was measured with pigs, while true protein digestiblity, biological value and net protein utilization were measured with rats.With pigs, there was no treatment effect on dry matter digestibility, but neutral detergent fibre digestibility was reduced in the dried barley. The apparent protein digestibility was markedly depressed to 44.5% for the alkali-treated grain compared with a mean of 65.1% for the other treatments (P < 0.001). In the rat trial, true digestibility of nitrogen and biological value were severely depressed (P < 0.001) by alkali treatment, but differences between the other treatments were relatively small.     

Ensiling characteristics, nutrient composition, and in situ ruminal and whole tract degradability of brown midrib and leafy corn silage

A study was conducted to compare the ensiling characteristics, chemical composition, and the ruminal and total tract nutrient degradabilities of leafy (Cargill F227) and brown midrib (Mycogen TMF94) corn silage hybrids. Corn was grown in Saint-Jean-sur-Richelieu, Quebec, Canada, harvested at a target 350 g kg(-1) dry matter (DM) content, and ensiled in mini-silos for 0, 2, 4, 8, 16, and 45 d. Two non-lactating Holstein cows fitted with ruminal and proximal duodenal cannulae were used to determine ruminal and whole tract nutrient degradability. Forage from both hybrids went through a rapid fermentation with a sharp decline in pH during the first 2 d of ensiling, pH in both silage being less than 4.0 after 45 d. Lactic acid concentration was however greater for leafy than brown midrib corn. Chemical analysis of silage after 45 d of ensiling revealed that hybrids differed in their composition. Compared to leafy corn, brown midrib corn had lower neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), crude protein (CP), and neutral detergent and acid detergent insoluble proteins, but higher starch and net energy of lactation (NEL) values. Results of the in situ incubation experiment indicated that compared to leafy corn brown midrib corn had greater ruminal DM (64 vs. 54%), CP (73 vs. 71%), and NDF (32 vs. 24%) degradabilities. Brown midrib corn silage also had greater DM ruminal (53 vs. 48%) and total tract (67 vs. 61%) digestibilities, as well as greater NDF ruminal (34 vs. 25%), intestinal (10 vs. 8%), and total tract (43 vs. 33%) digestibilities. Type of corn hybrid will thus greatly affect silage chemical composition and nutrient digestibility.     

Fiber digestibility in juvenile Galapagos tortoises (Geochelone nigra) and implications for the development of captive animals

Digestive strategies have been recognized to be a key factor for healthy growth in juvenile Galapagos giant tortoises (Geochelone nigra). The aim of present study was to investigate digestive coefficients with special regard to fiber fractions. Four captive bred Galapagos giant tortoises 4–5 years of age were fed a controlled diet for 32 days. The diet consisted of 77% hay, 15% tortoise pellets, and 8% apples on a dry matter basis. On a dry matter basis diet analysis showed: 95.7% organic matter, 11.3% crude protein, 20.5% crude fiber, 22.6% acid detergent fiber, 5.0% acid detergent lignin, and 17.6% cellulose. Based on total fecal collection during 7 days average dry matter digestibilities were calculated: 65% for dry matter, 67% for organic matter, 63% for crude protein, 55% for crude fiber, 49% for acid detergent fiber, 41% for acid detergent lignin, 54% for cellulose. An increase in crude fiber content resulted in a reduced digestibility in comparative evaluations of data for different tortoise species, and in a comparison of tortoises and mammalian hindgut fermenters. Compared to some mammalian hindgut‐fermenting herbivore species (domestic horses, Asian elephants, Indian rhinoceroses) on a diet of hay and concentrates, the juvenile Galapagos giant tortoises showed a digestion of similar efficiency. If a reduction in dietary digestibility is warranted in juvenile Galapagos giant tortoises, it is concluded that dietary fiber levels should be increased and it is proposed that crude fiber levels of 30–40% on a dry matter basis should be achieved. Zoo Biol 24:185–191, 2005. © 2005 Wiley‐Liss, Inc.     

A method using solubility to predict dry matter digestibility of cellulosic materials.

A rapid chemical procedure based on the solubility of a holocellulose sample in a system of dimethyl sulfoxide with paraformaldehyde has been developed to provide a laboratory method for predicting dry matter digestibility of cellulose containing samples. The amount of dry matter solubilized by the chemical procedure was closely correlated with anaerobic, in vitro, rumen fluid digestion and with digestibility as measured by aerobic Cellulomonas, sp. bacteria. The quantity of solvent and dissolving time had little effect on solubility over a wide range. The method is rapid, well suited for various cellulosic materials, and may be carried out with simple equipment and facilities.     

Laboratory evaluation of ensiled mixtures of alkali-treated cattle excreta and whole-crop maize

Faeces or manure (faeces + urine + straw bedding) from beef cattle given maize silage diets were ensiled with whole-crop maize (27% dry matter), after treatment with NaOH at 0, 7.5 or 15 g per 100 g excreta DM, so that excreta DM comprised 25, 50 or 100% of the total DM, in a factorial design. A control treatment consisted of maize forage ensiled alone. The ensiled products were analysed for the content of fermentation acids, pH, nitrogenous compounds, structural carbohydrates, starch, water-soluble carbohydrates, ash, sodium and digestibility in vitro. Mixtures which contained 25% excreta DM were well preserved with relatively low values for pH, butyric acid and ammonia-N, and a high proportion of fermentation acids as lactic acid. Mixtures which contained 50% excreta DM were generally poorly preserved. Addition of NaOH to excreta prior to ensiling was reflected in a decrease in the content of neutral detergent fibre and increased digestibility of organic matter in vitro in the ensiled products. Mixtures of 25% excreta treated with 15 g NaOH/100 g excreta DM gave values for digestibility in vitro similar to that of the maize ensiled alone.     

Yield,composition and nutritive value of a leaf protein concentrate obtained by fractionating the shelled aerial part of Pisum sativum L.

A leaf protein concentrate (LPC) extracted from shelled plants of pea (Pisum sativum L.) yielded 108 kg DM ha^?1. Dry matter (DM) was analysed for ether extract (13.59%), neutral detergent fibre (NDF, 1.79%), acid detergent fibre (ADF, 0.81%) and total ash (10.57%). The main nitrogen fraction was represented by protein-N (92% of total N). Mineral composition showed an adequate ratio of Ca to P (3). Lysine was present in nutritionally suitable amounts (7.42 g per 100 g recovered amino acids), but methionine was not (1.78). Apparent digestibility (AD; 75.5), true digestibility (TD; 87.6), biological value (BV; 68.8) and net protein utilisation (NPU; 59.7) were determined with Wistar albino rats. Methionine addition improved AD (81.3), BV (80.6) and NPU (70.5), although not TD (87.5) which was already very high.     

Chemical defense in birch: Inhibition of digestibility in ruminants by phenolic extracts

Summary The biological activity of phenolic extracts originating from winter twigs of birch (Betula pendula Roth.) was measured using the ruminant in vitro method and the nylon bag technique. Different extracts were prepared by extraction with organic solvents, removing phenols of corresponding solubility. The extract of birch twigs (diameter <1.5 mm) contained about 19% phenol equivalents, corresponding to 6% of twig dry matter (DM). Coarse birch twigs (diameter 1.5–5 mm) contained about 3% in the DM Phenolic extracts from the fine birch twigs were added to coarse birch twigs and common timothy (Phleum pratense L.) to mimic natural concentrations of fine birch twigs. Controls and the plant material with phenolic extract added were incubated for different times with rumen inocula taken from a sheep fed browse and a goat fed hay. Nylon bags containing phenolic treated hay were incubated in the rumen of the goat for 6 and 48 h. Phenolic extracts had a considerable negative effect on the organic matter (OM), protein and cell wall (neutral detergent fiber, NDF) digestibility in vitro. The nylon bag OM disappearance was also depressed by the extract. The effects were measurable after 6 h of digestion both in vitro and in sacco.The high inhibitory effect by the extracts on digestibility persisted even after removal of lipophilic fractions. This suggests that some or several water-soluble phenolic substances are responsible for the depression of digestibility. The depression of OM digestibility is linearly related to the concentration of phenols added. However, the inhibition of nylon bag digestibility plateaus at high phenol concentrations, suggesting that some fraction of the substances undergo complex formation with macromolecules of the plant.The results strongly indicate that water-soluble phenols of birch make up an important part of its chemical defense in winter by possessing antinutritional properties. Thus their potential importance in the nutrition of wild herbivores must not be ignored.