Digestibility Of Cell Wall Constituents Research Articles

Potential of waste flowers used as feed additive on the performance of goat kids

The present study was conducted to assess the impact of temple waste flowers as feed additive on the growth of goat kids. Marigold (Calendula officinalis) flowers constituted the bulk of WFs with negligible red roses (Rosa indica L). Marigold flowers as compared to rose flowers contained high (P<0.01) total phenols and flavonoids; and low (P<0.01) anthocyanins, saponins and vitamin C content. The in vitro studies revealed that the supplementation of WFs at 3 and 5% improved (P<0.01) digestibility of nutrients and VFAs production as compared to control. NGP at t½ increased (P<0.05) linearly up to 4% WFs supplementation and methane production decreased (P<0.05) at all levels of supplementation. Fifteen Beetal goat kids divided into three equal groups were fed TMR, or TMR supplemented with WFs at 3 or 5% of DM intake for 90 days. The daily DM consumed by the animals was similar in all the groups. The digestibility of proximate constituents at 3% level of WF was comparable with control TMR, but depressed (P<0.05) at 5% level of supplementation. The digestibility of cell wall constituents and N retention were not affected by WF supplementation. The average daily gain in weight was improved considerably. It was concluded that bio-active compounds present in WFs reduced the methane emission, resulting in improvement in nutrient utilization and growth of goat kids.

PRODUCTION PERFORMANCE OF SMALL RUMINANTS FED PRUNING FRUITS TREES BY PRODUCTS. 2- EFFECT OF TREATED PRUNING PEACH TREES BY-PRODUCTS ON GROWING SHEEP.

This experiment was conducted to study the effect of chemical and biological treatments of pruning peach trees by-products (PTBP) on chemical composition, degradability, cell wall constituents, digestibility and nutritive value and its feeding effect on productive performance of growing sheep. Thirty Ossimi lambs with average body weight 18.00±0.20 kg and 4 months old were used in this study for 120 days. Lambs were distributed into five similar groups (6 lambs each) and randomly assigned to five experimental rations. The five respective rations composed of concentrate feed mixture (CFM) + roughage (PTBP), the control ration (R1) contained untreated PTBP; (R2) treatedPTBPwithTrichoderma reesei; (R3)treated PTBP with Trichoderma viride;(R4) treated PTBP with Trichoderma reesei + Trichoderma viride and (R5) 3% urea treated PTBP. The DM, OM and CP disappearance and effective degradability (ED) va lues were in situ determined. The digestibility and nutritive values of experimental rations were determined using fifteen adult Ossimi rams. Rumen liquor and blood samples were collected at the end of collection period. The results showed that fractions of DM (a&b) and (ED) were significantly (P<0.05) increased with treated PTBP either with urea or fungi compared to control (untreated PTBP). The highest degradable values of DM, OM and CP were observed with R4. Nutrient digestibility and feeding values (TDN and DCP) were higher (P<0.05) for rations containing treated PTBP than control. The highest values of TDN and DCP were observed for R4. Digestibility of cell wall constituents (NDF, ADF, cellulose and hemicellulose) were improved by treatments. Concentrations of rumen parameters (NH3-N and TVFA’s) were significantly increased by treatments. However, no significant differences were found in blood constituents (total protein, albumin, globulin, GOT, GPT and urea) among the different experimental groups. Blood constituents were generally normal in all experimental groups. Growth performance with respect to total body weight gain and average daily gain (ADG) were improved by biological treatments. The same trend was observed for feed conversion and economic efficiency and the best values were recoded with R4. It was concluded that inclusion of treated PTBP to rations of growing Ossimi lambs could improve their performance especially treatment of PTBP with fungi.

Nutrient utilization and growth performance of defaunated and faunated lambs maintained on complete diets containing varying proportion of roughage and concentrate

Nutrient utilization, feed conversion efficiency and growth performance of defaunated and faunated growing lambs maintained on complete diets containing different proportion of roughage and concentrate were evaluated in a 90-day experiment. Sixty Malpura weaner (90 days) lambs with average body weight of 13.2 kg were randomly divided into six equal groups (G1, G2, G3, G4, G5 and G6) of 10 lambs each. All lambs were defaunated by administration of sodium lauryl sulfate at the rate of 8 g/100 kg body weight as a 10% aqueous solution, infused directly into the rumen by stomach tube for two consecutive days. Six days after defaunation, all the lambs of G4, G5 and G6 groups were refaunated by inoculation of 100 ml per lamb rumen content drawn from normal faunated and fistulated rams. The lambs of G1 and G4, G2 and G5, and G3 and G6 groups were maintained on three complete diets in which the roughage and concentrate ratio were 50:50, 65:35 and 80:20, respectively. The digestibility of cell wall constituents was poor in defaunated lambs while daily intakes of digestible crude protein (DCP) and digestible energy (DE) were similar in defaunated and faunated lambs. Irrespective of the presence or absence of rumen protozoa, digestibility of dry matter (DM), organic matter (OM), crude protein (CP) and energy increased, while digestibility of cell and cell wall constituents decreased with increase in dietary proportion of concentrate resulting in their higher daily intake of DCP and DE. Even with similar DM, DCP and DE intake during the experiment, nitrogen retention, total body weight gain, average daily gain and feed conversion efficiency were better in defaunated than faunated lambs. With decreased dietary proportion of concentrate the body weight gain and feed conversion efficiency decreased both in defaunated and faunated lambs. It is concluded from the study that with similar intake of DM, DE and DCP, the growth performance and feed conversion efficiency were better in defaunated than in faunated lambs.

Different means of administering polyethylene glycol to sheep: effect on the nutritive value of Acacia cyanophylla Lindl. foliage

AbstractPolyethylene glycol-4000 (PEG) was used to inactivate tannins in Acacia cyanophylla Lindl foliage. In the first of two experiments, four groups of five Barbarine sheep were held in metabolism crates so that intakes, apparent digestibilities, nitrogen balances and urinary excretion of allantoin could be measured. The second experiment involved four groups of three male Queue Fine de l'Ouest sheep fitted with rumen cannulae and housed in individual pens to measure rumen fermentation parameters and dry matter in situ degradation of A. cyanophylla foliage. All animals received fresh A. cyanophylla foliage ad libitum and 330 g concentrate on a daily basis. In each experiment, three groups of sheep received 20 g PEG daily, either mixed with concentrate (PEG-concentrate), dissolved in drinking water (PEG-water) or sprayed as a solution on A. cyanophylla foliage at the point of feeding (PEG-treatment). The fourth group was not supplied with PEG (control). Dry-matter intake of A. cyanophylla was low (28·3 g/kg metabolic live weight (M0·75) per day) and increased in sheep given the PEG-concentrate diet (38·2 g/kg M0·75 per day). PEG-concentrate and PEG-water diets resulted in an improvement in protein utilization as indicated by an increase of crude protein apparent digestibility (2·1 and 1·9 fold, respectively), nitrogen retention (3·2 fold with both dietary treatments) and urinary excretion of allantoin (1·9 and 1·5 fold, respectively). Improvements obtained with PEG-treatment diet were low and in general not significant (P &gt; 0·05). Low neutral-detergent fibre and acid-detergent fibre apparent digestibility coefficients of diets led to the conclusion that conventional detergent extraction techniques are questionable in determining the in vivo digestibility of cell wall constituents for tannin-rich forages. Results from rumen fluid analyses indicated that sheep given PEG-containing diets had higher ammonia-nitrogen and volatile fatty acid (VFA) concentrations (P &lt; 0·05). These results, coupled with the increase of allantoin excretion gave clear evidence that the efficiency of microbial synthesis was improved with PEG addition. The absence of change in ruminal pH and molar proportions of individual VF A suggested similar fermentation patterns among all dietary treatments. PEG supply increased the slowly degradable fraction of A. cyanophylla foliage incubated in the rumen (P &lt; 0·05), thus dry matter potential degradability (a + b) was highest in sheep given PEG-containing diets. It is concluded that the affinity of acacia tannins to PEG, increased the availability of degradable proteins, which resulted in an improvement of the nutritive value of acacia foliage. However, for practical situations, adding PEG to concentrate or to drinking water is recommended for sheep browsing A. cyanophylla trees in the field or fed indoors.

Methane suppression by coconut oil and associated effects on nutrient and energy balance in sheep

Three different diets with increasing proportions of coconut oil (0, 3.5 and 7%) were fed to six sheep in an incomplete Latin square experiment with four replicates per diet. The diets were composed of hay and concentrates either without or with coconut oil. Concentrate comprised 28.8 and 54.6% of the diet DM in the treatments containing 3.5 and 7% coconut oil, respectively. Wethers on all treatments were fed at 1.2 × maintenance. Gaseous exchange was measured in respiratory chambers. Protozoa counts were reduced (P &lt; 0.05) by 88 and 97% when diets contained 3.5 and 7% coconut oil, respectively, whereas bacteria counts increased (P &lt; 0.05). Supplementation of coconut oil at proportions of 3.5 and 7% suppressed (P &lt; 0.001) methane production by 28 and 73%, respectively, as related to the unsupplemented diet. This proportionately reduced (P &lt; 0.001) the amount of gross energy lost through methane from 7.5 to 5.7 and 2.5%, in diets containing 0, 3.5 and 7% coconut oil, respectively. Assuming a linear suppressive effect of coconut oil, about half of the additional methane reduction with the 7% coconut oil diet as compared with the 3.5% diet was attributed to the substitution of concentrate for hay. Digestibility of cell wall constituents was numerically decreased by coconut oil. Apart from this and its effect on methane emissions coconut oil had no major influence on digestion or on energy and nitrogen balance. Key words: Coconut oil, methane, energy balance, sheep, ruminants

Effects of light intensity on growth, anatomy and forage quality of two tropical grasses (Brachiaria brizantha and Panicum maximum var. trichoglume)

Effects of light intensity on growth, histology and anatomy, and nutritive value were studied in seedlings of two shade tolerant species: Brachiaria brizantha and Panicum maximum var. trichoglume. They were studied under greenhouse conditions in pots with sandy soil and sufficient N and cut after a growth period of 8 weeks. High light intensity stimulated growth, tillering and yield per tiller and increased stem proportion. It greatly increased number of sclerenchyma cells, their wall thickness in all organs and the content of cell wall constituents. High light intensity also reduced concentrations of total N, NO3-N and ash appreciably. It reduced digestibility of cell wall constituents in leaf blades but increased it in leaf sheaths and stem, especially in Panicum. Variation in sclerenchyma tissue could be associated with variation in percentage of cell wall constituents, but not with variation in cell wall digestibility. The result of these effects of light intensity on composition of organs was a higher digestibility of organic matter of the whole crop at lower light intensity. Brachiaria was more tolerant to shade than Panicum with regard to growth, N-concentration and digestibility, but it accumulated more nitrate. It was suggested that light intensity may affect forage quality little under low nitrogen supply in the tropics, but effects may be larger at ample nitrogen supply. Individual species may partly divert from this general pattern.

Apparent digestibilities of energy, cell wall constituents, crude protein and amino acids of Chinese oil seed meals for growing pigs

The apparent ileal and faecal digestibilities of energy, crude protein (CP), amino acid and cell wall constituents in feedstuffs of peanut meal (PNM), soyabean meal (SBM), rapeseed meal (RSM-1), ammoniated rapeseed meal (RSM-2), partly dehulled cotton seed meal (CSM) and rice bran cake (RBC) were determined for non-cannulated pigs ( n=6) or pigs ( n=6) fitted with ileo-caecal reentrant cannulae. The pigs were fed with a cornstarch-based diet formulated to contain about 14% protein. The results showed that the ileal digestibility of energy was not significantly different between SBM (76.2%) and PNM (74.4%), but that it was significantly lower for RBC ( P<0.05) than for SBM and PNM. However, the ileal digestibility of energy was significantly lower for RSM-2, RSM-1 and CSM than for RBC. The ileal digestibility of CP was significantly higher for PNM (87.3%) than for SBM, and was significantly higher for SBM than for RBC (73.4%) and CSM (73.0%). Although the ileal digestibility of CP was significantly higher for RSM-2 than for RSM-1, it was significantly lower for RSM-2 than for CSM and RBC. CSM had the lowest ileal digestibilities of lysine (43%), methionine (64%) and threonine (67%), which are the most important amino acids in amino nutrition. The ileal digestibility of lysine was highest for SBM ( P<0.05), but that of methionine was highest ( P<0.05) for RSM-2. PNM, SBM and RSM-2 had a similar ileal digestibility of threonine. PNM contained not only the highest amount of arginine (76.6 g kg −1 DM), but also had the highest ileal digestibility of arginine (92%). In general, the faecal analysis method overestimated the digestibility value of nutrients. The modifying action of the bacteria in the large intestine is irregular, therefore a precise determination of the apparent digestibilities of nutrients, especially the amino acids, cannot be obtained from the faecal analysis method. In contrast to previous findings, a high ileal digestibility of cell wall constituents was found for oil seed meal.

Nutritive value of feedstuffs and diets for pigs: I. Chemical composition, apparent ileal and faecal digestibilities

The chemical composition, including amino acid content, and ileal and faecal digestibility was determined for 39 batches of 38 different feedstuffs and 18 mixed diets. Considerable variation was found in both chemical composition and digestibility among cereals and cereal by-products, legumes, animal protein feedstuffs, oil seed meals, protein and mineral concentrates and mixed diets. Within the different classes of feedstuffs and diets, variation was small for mixed diets and protein and mineral concentrates. A large variation was found for animal protein feedstuffs and oil seed meals, especially for apparent ileal digestibilities of amino acids. However, there was good agreement between the results and those reported in the literature. The digestibilities of nutrients were affected by many factors, including cell wall constituents, the balance of mineral and trace elements and anti-nutritional factors. Faecal digestibility was higher than ileal digestibility. In general, the differences between apparent faecal digestibilities were smaller than for apparent ileal digestibilities. This indicates that the modifying action of microflora in the large intestine is irregular, therefore the digestibility measured at the end of the ileum is more reliable. However, the high ileal digestibility of cell wall constituents indicates that the influence of the microflora begins before the end of the ileum, and other methods such as isotope dilution techniques should be used to more accurately determine digestion and absorption.

The effects of forage preservation method and proportion of concentrate on digestion of cell wall carbohydrates and rumen digesta pool size in cattle

AbstractSix bulls with ruminal and duodenal cannulae were used in a 6 × 6 Latin square design with a 2 × 3 factorial arrangement of treatments. Barn‐dried grass (G) and direct‐cut silage (S) from the same sward were fed together with 250 (L), 500 (M) and 750 (H) g kg‐1 total dry matter (DM) of a barley‐based concentrate (barley 875 and rape‐seed meal 125 g kg‐1) at the level of 80 g DM kg‐1 live weight0·75. Rumen and total digestibility of cell wall constituents were measured by a double marker and total collection method. Rumen pool sizes of dietary constituents were estimated by emptying the rumen. Particle‐associated enzyme activities were measured from rumen particulate material and feed particles incubated in nylon bags in the rumen.Neutral detergent fibre (NDF) and hemicellulose digestibility were higher (P&lt;0·05) for G diets than for S diets while no differences were observed between the forages in acid detergent fibre (ADF) and cellulose digestibility. Both rumen and total digestibility of cell wall constituents decreased with increasing level of concentrate. The proportion of total cell wall digestion in the rumen was unaffected by the forage preservation method and the proportion of concentrate. NDF, and especially cellulose digestibility, declined quadratically with increasing level of concentrate. Dietary effects on particle‐associated carboxymethylcellulase and xylanase activity were consistent with those observed in cell wall digestion. There were no differences between the forages in rumen pool size of total ingesta or any dietary constituent. Rumen pool size of total ingesta decreased with increasing level of concentrate. On the other hand, DM content of ingesta increased with the level of concentrate, while the pool size of DM, NDF and ADF declined quadratically reaching a minimum on M level of concentrate. The differences in rumen NDF pool size were mainly in the digestible fraction. Calculation of digestion kinetic parameters showed that both the rate of passage and especially the rate of digestion were markedly depressed in animals fed on the highest level of concentrate. The results suggest that a reduced fate of digestion of NDF with high concentrate diets can be partially compensated for by an increased NDF retention time in the rumen of animals fed at a restricted level of feeding.

Intake and digestion in swamp buffaloes and cattle. 1. The digestion of rice straw (Oryza sativa)

SUMMARYFour swamp buffaloes (Bubalus bubalis) and four crossbredBos indicusxB. tauruscattle, fistulated at the rumen and abomasum or duodenum, were offered rice straw with mineral supplements in two experiments. In Expt 1, the straw was supplemented with 5% of leaf ofLeucaena leucocephala, and in Expt 2 with either urea or urea with sunflower meal and rice grain. Intake of supplements of urea or urea/sunflower/rice respectively was 935 and 681 g/kg offered in buffaloes and 566 and 789 in cattle.Buffaloes ruminated longer than cattle (Expt 1, 635v. 452 min/day; Expt 2, 626v. 466 min/day,P&lt; 0·01). In Expt 1, voluntary intake and frequency of ‘A’ sequence forestomach contractions of both species was not affected by species, but buffaloes had a greater (P&lt; 0·05) contraction force in the rumen and omasum, lower rate of ‘B’ sequence rumen contractions, and faster (P&lt; 0·001) rate of gastrointestinal passage than cattle. In Expt 2, voluntary intake of both species was similar, and addition of concentrates did not affect voluntary roughage consumption, norin siturate of digestion of rice straw. Rate and predicted extent of digestion of dietary materials did not differ between species in Expt 1, despite lower concentrations of ammonia in rumen fluid in cattle than buffaloes; however in Expt 2, the rate of digestion of rice straw was higher (p&lt; 0·05) and predicted extent of digestion was 14–20% (P&lt; 0·05) lower in buffaloes. Digestibility of cell wall constituents was lower (P&lt; 0·05) in buffaloes than in cattle in both experiments, but in Expt 2, provision of concentrates reduced (P&lt; 0·01) the proportion of digestible cell wall constituents digested in the forestomach of buffaloes, but not of cattle.

Intake and digestion in swamp buffaloes and cattle. 2. The comparative response to urea supplements in animals fed tropical grasses

SUMMARYSwamp buffaloes (Bubalus bubalis) and crossbred cattle (B. indicusxB. taurus) were offered two forages in two experiments. In Expt 1, four animals of each species were offered mature Rhodes grass hay (Chloris gayana) with a mineral supplement or with a supplement of minerals and urea (17·6 gN/d). In Expt 2, another group of four buffaloes and four cattle were offered mature spear grass hay(Heteropogon contortus) with mineral supplementation at intervals of 3 h. Four levels of urea (0, 5, 21 and 97 g/day) and35S-sulphate were continuously infused in four periods.Rhodes grass was consumed in greater amounts by cattle, whereas buffaloes ate more spear grass. Urea supplements increased intake of Rhodes grass by 12% in buffaloes and 22% in cattle, and of spear grass by 34% in buffaloes and 41 % in cattle. Digestibility of cell wall constituents and acid-detergent fibre of spear grass was lower (P&lt; 0·05) in buffaloes than in cattle (417v. 499; 471v. 560 g/kg respectively). In Expt 2, dry matter digestibility progressively increased (P&lt; 0·05) from 364 to 408 g/kg with increased urea infusion. Rumen dry matter pool increased by 11–21 % on infusion of 97 g urea/day, compared with no urea. Digestion of ground forages incubatedin situin the rumen was depressed below rumen ammonia levels of 30–60 mg N/l, while digestion of cotton thread was depressed below 60–80 mg N/l (Expt 1) or 150–200 mg N/l (Expt 2).Patterns of N content in cotton thread suggested that more microbes attached in buffaloes and there was subsequently faster detachment than in cattle, particularly with increased urea infusion.

Effect of concentrate supplementation to grass silage diets on rumen fermentation, diet digestion and microbial protein synthesis in growing heifers

A 4 x 4 latin square experiment was carried out with four growing heifers, each with a rumen cannula and a simple T-cannula inserted in the proximal duodenum. The purpose was to study the effects of the supplementation of concentrate to grass silage on rumen fermentation, microbial protein synthesis and digestion of organic matter (OM), fibre components and N. The diets were composed of grass silage alone (S); grass silage and barley (SBU, 50:50 % on dry matter (DM) basis); and grass silage, barley and protein concentrate based either on rapeseed meal (SBR), or meat and bone meal (SBM) (50:40:10). To make the diets isonitrogenous, 23 g of urea was given with the SBU diet. The supplementation of concentrates, irrespective of their type, increased the average rumen ammonia-N and total concentration of volatile fatty acids (VFA) and decreased the molar proportion of acetate. Inclusion of concentrates in the diet had a negative effect on the digestibility of cell wall constituents. The production of microbial protein and the efficiency of microbial protein synthesis were not affected by the diet. It appears, therefore, that the supply of nitrogenous constituents for rumen microbes through ruminally degraded protein was adequate in silage feeding, and that no extra benefit, at the utilized level of application, was gained by the supplementation of any of the concentrates.

Influence of different cannulation techniques on the pre-caecal digestibility of protein, amino acids and cell wall constituents from diets, containing different protein meals, in pigs

A direct comparison of the ileal digestibility of protein, amino acids and cell wall constituents, measured using the simple cannula (spot sampling) and re-entrant cannula (quantitative sampling) techniques, was carried out with six pigs fitted with each type of cannula. During the experiment, the live weights of the animals ranged from 40 to 90 kg. Six diets were offered, including the following: a commercial ration commonly used in China which is based on maize, rice husk meal and fish meal (B); two diets in which part of Diet B was replaced by 15% oil-tea camellia cake (BTM) or rapeseed meal (BRM); two monodiets of maize with a high (MHL) or low (M) lysine content, plus Diet M with 15% of the maize replaced by peanut meal (MPM). Chromic oxide formed 2 g kg −1 of the diets to permit calculation of digestibility by spot sampling. With the exception of one maize diet and the MPM diet, the spot-sampling method gave higher digestibilily values for dry matter, protein and amino acids than the quantitative sampling method. Conversely, the digestibility values of neutral detergent fibre (NDF), acid detergent fibre (ADF) and acid detergent lignin (ADL) measured with the simple cannula technique were considerably lower than these measured with the re-entrant technique. This study indicated that the re-entrant cannula technique cannot be replaced by the simple cannula technique in the determination of pre-caecal digestibility in monogastrics, particularly the digestibility of cell wall constituents of compound feeds.

In Vitro Digestibility of Dry Matter and Cell Wall Constituents of Smooth Bromegrass Forage1

The availability of forage cell walls to ruminants is dependent on the concentration and digestibility of cell wall constituents. The objectives of this study were to quantify genotypic variation for in vitro digestibility of individual cell wall constituents and relate this variation to variation in concentration of cell wall constituents of smooth bromegrass (Bromus inermis Leyss.). Eighteen clones were grown at Arlington, WI, and sampled in 1982 and 1984. Forage samples were harvested to simulate a normal first cutting. Samples were analyzed for cell wall constituents of dried forage and forage that had been previously digested by rumen microorganisms. In vitro digestibility (IVD) of cell wall constituents was computed from differences obtained between undigested and digested forage samples. Genotypic variation was significant for IVD of neutral detergent and acid detergent fiber (NDF and ADF, respectively), cellulose, and hemicellulose, but not for acid detergent lignin (ADL). In vitro digestibilities of dry matter, NDF, ADF, cellulose, and hemicellulose were mutually correlated, with r ≥ 0.87. Concentration and IVD of cell wall constituents generally were not correlated, with ‒0.52 ≤ r ≤ 0.22. Selection for divergent IVD of dry matter (IVDMD) resulted in similar changes to IVD of NDF, ADF, cellulose, and hemicellulose; differences between high and low IVDMD clone groups ranged from 37 to 42 g kg−1 for IVD of cell wall constituents. The additional information provided by determining IVD of cell wall constituents makes these selection criteria potentially valuable. Because of their close interrelationships and similar correlated selection responses, IVD of NDF, which is the easiest and least expensive to determine, would satisfactorily represent the other IVD variables in smooth bromegrass.

The intake and digestibility by sheep of oat straw and maize stover offered with different levels of noug ( Guizotia abyssinica) meal

In two experiments, noug meal was given to groups of five castrated male sheep to provide 14, 26 and 40% of diets based on maize stover and 18, 34 and 45% of diets based on oat straw, both roughages being given ad libitum. Two periods, each of 7 days, were used for the determination of total dry matter (DM) intake and digestibility by total collection. Nitrogen balance and rumen NH 3 concentration were also determined. The cereal straws were each given without supplement to one group of sheep. The intake of the roughages when given alone was similar but the apparent digestibility of cell wall constituents was higher for the maize stover than for the oat straw. The apparent digestibility of N was negative for both straws. The addition of noug meal caused an increase in total DM intake of the complete diet but this was accompanied by a decrease in the intake of the cereal straw. The intake of NDF was similar in all the diets studied but there was a small but significant decrease in intake of both diets containing high levels of noug meal. With both roughages the addition of noug meal significantly increased the digestibility of DM, organic matter (OM) and most cell wall constituents. The return attributable to noug meal diminished as its rate of inclusion increased and the relation could best be described by an equation of the form y = a + b log x. There are strong evidence of a positive associative effect of the noug meal on the digestibility of the cereal straws. The digestibility of the various components of noug meal was calculated by difference and the high values obtained provided further evidence of an associative effect. Nitrogen digestibility, rumen NH 3 and N balance were all increased by the addition of noug meal. Maintenance requirements for N calculated by regression of N balance on N intake were lower than recent recommendations. The addition of 15–30% of noug meal to the cereal straws studied would be expected to provide a production ration for ruminants.

Interrelationships Between Feed Quality, Digestibility, Feed Consumption, and Energy Requirements in Desert (Bedouin) and Temperate (Saanen) Goats

Intake of high quality roughage (alfalfa hay) by black Bedouin goats was lower than by Swiss Saanen goats. Bedouin goats have lower energy requirements and less tendency to accumulate solids. Apparent dry matter digestibility was higher in Bedouin than Saanen goats even when high quality hay was offered. It was more pronounced when a medium quality roughage (Rhodes grass mixed with alfalfa) was fed. Differences in apparent digestibility of dry matter were greater when a poor quality feed such as wheat straw was offered. Similar differences between the two breeds were noted in relation to the apparent digestibility of cell wall constituents (cellulose, hemicellulose, and lignin) and nitrogen. When medium quality roughage was fed, Bedouin goats apparently consumed enough energy to sustain both maintenance and production, whereas Saanen goats consumed only enough to maintain very low production.Bedouin goats maintained their body weight and solids on an energy intake up to 50% less than the estimated maintenance requirement of goats, whereas Saanen goats lost body weight and solids. It is suggested that reduction in metabolic rate helps desert ruminants cope with chronic energy shortage.

Urea as a source of ammonia for improving the nutritive value of wheat straw

The effect of straw ammoniation using urea as a source of ammonia on nutritive value of wheat straw was evaluated with male sheep in two experiments of Latin square design. In Experiment 1 treatments were: untreated straw (S1), untreated straw supplemented with 20 g urea kg −1 air-dry straw at feeding time (SU1), straw treated with 30 g anhydrous ammonia kg −1 air-dry straw (AS), straw ensiled with 40 g urea kg −1 air-dry straw (US1) and straw ensiled with 40 g urea plus 10 g sodium hydroxide kg −1 air-dry straw (UCS). In Experiment 2 treatments were: untreated straw (S2), untreated straw supplemented with 20 g urea kg −1 air-dry straw at feeding time (SU2), untreated straw supplemented with 120 g kg −1 air-dry straw of a urea—molasses mixture at feeding time (SUM), straw ensiled with 40 g urea kg −1 air-dry straw (US2) and straw stacked with 40 g urea kg −1 air-dry straw (USS). Straw was chopped before ensiling, while whole rectangular bales were used in treatments AS and USS of Experiments 1 and 2, respectively. Ammonia and urea treatments were carried out at ambient temperature and lasted 60 days. For all the treatments involving the hydrolysis of urea to ammonia (US1, UCS, US2 and USS) the moisture content of the straw was raised to ca. 40% by the addition of water. Straw in the long form was chopped prior to feeding. In all treatments straw was given as the sole feed, with a mineral supplement. In both experiments supplementation with urea or urea—molasses at feeding time significantly increased ( P<0.05) organic matter (OM) digestibility and digestible organic matter (DOM) intake over untreated straw by 47–72 g kg −1 and 4.9–6.2 g day −1 kg W −0.75, respectively. Treating straw by ensiling with urea raised OM digestibility and DOM intake further, the increments being 121–123 g kg −1 and 14.3–15.0 g day −1 kg W −0.75, respectively, over untreated straw. Digestibility of cell wall constituents was particularly enhanced by urea treatment. Urea treatment of stacked straw was less effective than urea treatment of ensiled straw. Anhydrous ammonia and urea treatment by ensiling promoted similar levels of DOM intake. Availability of retained nitrogen by ammoniated straws was high. It is concluded that urea can be an effective source of ammonia for straw treatment by ensiling.

The digestion of grass and alfalfa silages in the forestomachs and intestines of sheep.

Digestion of cell wall constituents (CWC) and crude protein (CP) were estimated in wethers fitted with dorsal rumen sac and small intestine cannulae and given grass or lucerne silage (containing in DM 12.9% and neutral detergent fibre (NDF) 60.2% and CP 19.1% and NDF 48.8%, respectively) with daily DM intakes 46.5 and 49.0 kg0.75. Highest rate of emptying of reticulo-rumen was for grass silage. Fractional rate of emptying of liquid phase for cows given grass silage was 5.7% per h compared with 4.9% per h for cows given lucerne silage. Rates of emptying of particulate phase were similar for both silages. Frequency of rumen contractions was higher for grass silage than for lucerne silage. CWC of lucerne silage were less digestible than those of grass silage. Degradability of dietary CP in reticulo-rumen for grass and lucerne silage was 64 and 87%. Digestibility of CP in the small intestine was lower for lucerne silage than for grass silage. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Variations and prevision of the in sacco dry matter digestion of concentrates and by-products

Twenty-four feeds, representative of the range of variation occurring in in vivo digestibility of cell wall constituents, were chosen to study the variations of in sacco dry matter digestion (DMDG). The shape of the DMDG curves varied considerably from one feed to another, and the GOMPERTZ model was generally more suitable than an exponential model to describe them. The NDF content was the best cell wall parameter for prediction of short-term DMDG. When the incubation duration increased, the A.D.Lignin content became the best predictor, particularly when feed having a DMDG of 48 – 50% was excluded from the data. The use of a standard sample (namely straw) in each incubation reduced the within-feed variation. This appeared to be an indispensable step for the use of in sacco DMDG curves as feed attributes.

Kuitumäärityksen merkitys kotieläinten ruokinnassa

Information is given on the chemical composition and digestibility of cell-wall constituents. Special attention is paid to the value of different analytical systems in the prediction of digestibility and nutritive value of feeds. As a part of the Weende analytical scheme, crude fibre is still of importance in feed tables. It is al used in farming practice as a rough quality criterion for forages and certain other feeds. In evaluating the digestibility of forages by an analytical system, however, the biological methods - especially in vitro and in sacco digestibilities - have proved superior to the Weende crude fibre and van Soest’s fibre analyses and to other chemical methods. Certain combinations of chemical and biological methods also have been found useful. The same systems are not available for concentrates. Schemes have been developed for concentrates based on the contents of starch, sugar, protein and fat.