Using rats, the protein content and quality of an enriched cassava-root meal (CRM) biomass, produced by growing Cephalosporium eichhorniae 152 on a CRM medium in a submerged fermentation, was compared with that of soya-bean meal (SBM) and cotton-seed cake (CSC) in rats. The contents of crude protein of these feeds were 38.8, 52.0 and 42.3% on DM basis, respectively, and there were differences in their amino acid composition. The nitrogen digestibility of the enriched CRM-biomass and of CSC was lower than that of SBM. The biological value of the enriched CRM-biomass was equal to that of CSC, but lower than that of SBM. Net protein-utilization estimates for the enriched CRM-biomass and for CSC were similar, whereas that for SEM was greater. Enriching CRM by C. eichhorniae 152 seems to be a way of increasing protein supply for livestock production.
Diaminopimelic acid (DAPA) concentrations within rumen bacteria, effluent and feed samples were determined by reversed phase high performance liquid chromatography using pre-column o-phthalaldehyde (OPA) derivatization. The derivatization procedure is rapid and is performed in aqueous medium at room temperature.This method utilized 4 M methanesulfonic acid containing 0.2% 3-(2-aminoethyl) indole rather than 6 N HCl for hydrolysis. Methanesulfonic acid has the advantage that the neutralized hydrolysate can be derivatized and applied directly to the column with minimal sample clean up.Ultraviolet detection was used to measure the OPA derivatives and β-aminoadipic acid was used as an internal standard. Bacterial and effluent samples were prepared in order to have the on-column DAPA concentration fall in the 100–800-picomole range, as both DAPA and β-aminoadipic acid were linear within this range. The relative recovery of standards added to rumen effluents ranged from 97.2 to 103.8%. The precision and reproducibility of this method was evaluated by analysis of 10 rumen bacterial hydrolysates and 8 rumen effluent samples, which yielded relative standard deviations of 3.4 and 2.6%, respectively.
A trial was conducted to study the influence of cooking–flaking (C-F) of maize and enzyme supplementation (ES) of the diet on mucosa morphometry, digestive organ weight, dietary component digestibility and growth performance of broilers from 1 to 21 days of age. There were 4 treatments arranged factorially with 2 heat processings of maize (raw and C-F) and 2 levels (0 and 500 mg/kg) of an enzyme complex with xylanase, protease and α-amylase activity. Dietary treatment did not affect any productive trait from 1 to 21 days of age. However, from 1 to 4 days of age, body weight gain (P<0.01) and feed conversion ratio (P<0.001) were improved by ES of the diet. Intestinal viscosity increased with C-F of maize and decreased with ES of the diet (P<0.001). The effects of ES on intestinal viscosity were more pronounced with C-F than with raw maize (P<0.001) and at younger than older ages (P<0.05). Cooking–flaking of maize increased total tract apparent digestibility of dry matter and organic matter (P<0.05) and of neutral detergent fibre and starch (P<0.001) and tended to improve ether extract (EE) digestibility (P<0.10). In addition, ES improved nitrogen retention (P<0.01) and EE digestibility (P<0.001). Digestibility of neutral detergent fibre and starch increased linearly (P<0.001) with age whereas nitrogen retention and organic matter, EE and gross energy digestibility decreased from 4 to 8 days of age and increased thereafter (P<0.001). The relative weight (g/kg body weight) of the pancreas decreased (P<0.01) and that of the liver increased (P<0.001) with C-F of maize. The relative weight of the proventriculus, gizzard and liver reached a maximum before 6 days of age and that of the small intestine and pancreas at approximately 7.8 days of age (P<0.001). Enzymes increased villus height (P<0.05) but did not affect villus width or villus surface area. It is concluded that C-F of maize improved dietary component digestibility but had no effect on broiler performance at 21 days of age. In addition, ES improved nitrogen retention, EE digestibility and productive performance of broilers but only from 1 to 4 days of age.
Intra- and inter-laboratory variation of in vitro gas production and calculated metabolizable energy (ME, MJ/kg DM) values were studied using 16 test feeds in 7 laboratories. Intra-laboratory variation was low, with six of the seven laboratories having very high relationships in gas production between runs (R2≥0.96) and slopes that did not differ from unity. Inter-laboratory differences were higher with highly significant (P<0.001) differences among laboratories in both gas production and calculated ME values. Three of the six test laboratories generated predicted ME values that did not differ from the seventh (reference) laboratory. Combining intra-laboratory variation in gas production and inter-laboratory variation in predicted ME values, three of the six test laboratories were judged acceptable overall. ME values predicted by the gas production technique by laboratories in different parts of the world cannot be considered absolute.
Straws of 51 varieties of six kinds of cereal (oats, 12; spring barley, 6; winter barley, 10; winter rye, 9; winter wheat, 9; triticale, 5) were separated into the botanical fractions: internodes, leaves plus leaf sheath, nodes and chaff. Samples of all fractions were ground (2 mm) and incubated (48 h) in the rumen of five sheep each using the nylon bag technique. Sheep consumed 1000 g artificially dried grass and 200 g concentrate pre-mix per animal day−1.Straws of spring cereals contained a lower weight proportion of internodes (44%) and a greater weight proportion of leaves (39%) than straws of winter cereals (58% and 22%, respectively). High variations were observed among the fractions of various varieties (e.g. internodes: oats. 42.0–53.8%; spring barley, 36.0–45.0%; winter barley, 58.0–70.0%; winter rye, 57.0–69.0%; winter wheat, 46.0–58.0%; triticale, 41.9–57.1 % of whole straw).In sacco degradability of leaves (spring cereal straw, 66%; winter cereal straw, 47%) and chaff (68% and 43%, respectively) was significantly higher than that of internodes (40% and 32%) and nodes (48% and 37%, respectively). High variations were found in the in sacco degradability of botanical fractions of various varieties.The following sequence of in sacco degradability of whole straw was mostly influenced by the proportion of fractions and their in sacco degradability: oats, 56.8 (49.2–65.4%); spring barley, 49.6 (46.1–54.2%); triticale, 42.4 (29.8–51.9%); winter wheat, 41.3 (36.7–45.9%); winter barley, 37.2 (33.6–44.9%); winter rye, 29.2 (25.5–35.6%). Grain yield was not significantly correlated with botanical weight proportions or in sacco degradability.Straw of spring cereals contains more leaves and is more degradable in the rumen than straw of winter cereals; therefore, it should be used primarily for feeding.
The ensiling characteristics of barley, triticale and wheat grains at two different moisture levels, with and without the addition of lactic acid bacteria (LAB, Lactobacillus plantarum DSMZ 8862 and 8866) were determined after a 50-day storage period. In addition, the impact of the different ensiling techniques on the nutritional value was determined in pigs. In Experiment (Exp.) 1, mature grains were ground and water was added to adjust the moisture to 250 g kg−1 (low moisture content, LMC) or 350 g kg−1 (high moisture content, HMC). Grains were ensiled in laboratory scale silos for 3, 10 and 50 days. In the HMC silos, pH declined within 3 days irrespective of LAB treatment. In the LAB treated LMC, pH declined after 10 days of storage, whereas pH of untreated grains remained unchanged. Lactic acid production was higher (P<0.05) in HMC than in LMC grains, with almost no acid production with the untreated LMC grains. Denaturing gradient gel electrophoresis analysis revealed that the composition of the bacterial communities changed when LAB was added.Nutrient digestibility of HMC and LMC grains ensiled for 50 days with addition of LAB and untreated dry grains was determined separately for each grain in pigs. Digestibility was increased in LMC (crude fibre, crude protein, phosphorus) and HMC (ether extract) wheat grains, whereas only ether extract digestibility was improved in HMC triticale and no differences were observed for barley. A higher (P<0.05) phosphorus digestibility was observed in LMC triticale and wheat as compared to the dry grains, likely due to reduced phytate-P after ensiling. The results show that cereals with a moisture content of 250 g kg−1 can be ensiled successfully provided that LAB is added, and that under these conditions phosphorus availability is increased.
Greater production demands for ruminants require increased dietary inclusion of high-energy feeds. Grains and oil seeds are most commonly used to enhance diet energy density. However, use of such feeds proportionally increases the amount of dietary phytate phosphorus (P), which the ruminant may not be able to fully utilise. Our objectives for this study were to determine the extent of phytate degradation and mineral digestion in wethers fed high-grain diets consisting of either a non-mutant or low-phytate mutant barley grain. In two separate experiments, mature Columbia wethers (n = 7) fitted with rumen and duodenal cannulas and Columbia × Polypay wether lambs (n = 8) were individually fed one of two finishing diets formulated with either non-mutant Harrington (HARR) variety or low-phytate mutant-M 955 (M955) barley grains. Total-P intake was similar (P=0.46–0.70) between the M955 and HARR treatments for mature (5756 and 5550 mg/day, respectively) and lamb (5207 and 4894 mg/day, respectively) wethers. Dietary water-soluble P was 3.6 times greater in M955 versus HARR diets and phytate P was 11 times greater in HARR versus M955 treatment diets. Apparent total-P digestion was similar between M955 and HARR treatments (P=0.52–0.69). More monoester P was identified in the duodenal chyme of mature wethers fed HARR treatment diet, presumably due to incomplete hydrolysis of phytate P in the rumen. Feeding M955, compared to HARR, treatment diet resulted in greater (P<0.05) apparent partial-tract digestion of calcium (Ca) and total-tract digestion of iron (Fe), magnesium (Mg), and zinc in mature wethers and apparent total-tract digestion of Mg and Fe and retention of Ca, Fe, and Mg in wether lambs. These results indicate that phytate in diets formulated with Harrington variety barley grain may not be fully digested in the rumen. Subsequent passage of partially digested phytate from the rumen may interfere with mineral digestion in wethers fed high-grain diets.
Two experiments were conducted to study the absorption of synthetic L-lysine and of heat-treated lysine in growing pigs. In the first experiment, three cross-bred pigs were fed on a control diet (6.9 g lysine kg−1) or the same diet supplemented with L-lysine or treated lysine (5.5 g lysine kg−1) in a cross-over experiment. Both lysine treatments caused six-fold increases in the concentration of lysine in the blood plasma between 1 and 2 h after feeding. The concentrations of lysine in plasma returned to pre-feeding levels 6 h post-feeding.In the second experiment, the basal diet supplemented with the two forms of lysine was given to 6 pigs. The apparent digestion of lysine to the terminal ileum was found to be complete for both forms.
It is known that extraction of some grasses with neutral detergent (ND) increases the in vitro digestibility [Kennedy, P.M., Lowry, J.B., Conlan, L.L., 1999. J. Sci. Food Agric. 79, 544]. Here, we report experiments which defined the contribution of ND components to digestibility increases. Substrates were prepared from spear grass (Heteropogon contortus) by boiling at neutral pH in solutions of 0.05 M disodium EDTA, 0.018 M sodium borate, and 0.03 M sodium phosphate, and a mixture of the three solutions. Phosphate was the most effective single component in increasing ND fibre (NDF) digestibility in vitro, after 120 h of fermentation, from 472 to 522 g/kg NDF, equivalent to 68% of the increase found with boiling ND. NDF digestibility of bagasse at 120 h increased from 162 to 186, 230 and 277 g/kg NDF after boiling for 1 h in water, neutral phosphate and ND, respectively.Phosphate treatment of bagasse produced a 44% increase in NDF digestibility, compared to increases of 5, 8, 14, and 16 % for rhodes grass (Chloris gayana), spear grass, angleton grass (Dicanthium aristatum) and carpet grass (Axonopus affinis), respectively. Increases of cumulative gas production against incubation time indicated that most of the increased fermentation had occurred by 24 h of fermentation for the grasses, whereas 72 h was needed for bagasse. There were also improvements in NDF digestion with neutral phosphate treatment of spear grass at temperatures of 75, 85 or 95°C, with prolonged treatment times required at lower temperatures. These treatments reduced the content of acid insoluble ash in NDF and increased the rate of production of gas during fermentation. Removal of minerals from the cell wall matrix appeared to be responsible for the increase in NDF digestibility caused by phosphate treatment. The possible commercial use of phosphate on-farm to upgrade nutritional quality of straws is discussed.
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.
Feeding dairy cows with rumen protected n-3 fatty acids (FAs) derived from oilseeds or marine oils significantly increased the proportion of these acids in milk fat. Feeding protected canola/soybean oilseed (70/30, w/w) and soybean oilseed/linseed oil (70/30, w/w) supplements increased the proportions of C18:3 from 0.8 to 2.49 and 0.64 to 8.45%, respectively. Feeding protected soybean oilseed/tuna oil (70/30, w/w) increased the proportions of eicosapentaenoic (C20:5) and docosahexaenoic (C22:6) from 0 to 0.86 and 0 to 1.41%, respectively, in milk fat. There were also increases in the proportions of linoleic (C18:2) and a simultaneous reduction in the saturated FAs myristic (C14:0) and palmitic, (C16:0) concentration, with no significant change in the proportion of stearic acid (C18:0). These changes in the fatty acid composition had pronounced effects on the thermal characteristics of milk fat with a much higher proportion of liquid fats at lower temperatures, which will improve spreadability of butter. The proportions of n-3 FAs increased in milk fat at higher supplementation rates, however, the efficiency of transfer declined. This relationship between supplementation and transfer rate will determine the optimal feeding regimes necessary to produce the desired proportions of n-3 FAs in milk and dairy products.
Pigs, 32 male and 32 female housed at a constant temperature of 25 °C were fed, ad libitum over the liveweight range 25–55 kg, diets containing 0, 100, 200 and 300 g kg−1 of copra meal which were balanced for their essential amino acid compositions. Inclusion of 100 g kg−1 copra meal resulted in slightly poorer growth rates compared with the control diet, but no further deterioration was observed up to 300 g kg−1 (P = 0.044). Increasing copra meal content of the diet was associated with a progressive reduction (P = 0.017) in the voluntary feed intakes of the animals, although feed conversion ratio was unaffected by dietary treatment. With increasing inclusion of copra meal, backfat thickness decreased at points P2 (P = 0.018) and P1 + P3 (P = 0.017). Increasing level of inclusion of copra meal was associated with increases (P < 0.001) in levels of lauric acid (C12:0) and myristic acid (C14:0) and decreases (P < 0.001) in stearic acid (C18:0) and linoleic acid (C18:2) in the bsckfat. Thsse changes reflected, to varying degrees, changes in the fatty acid composition of the dietary oil as the proportion of coconut oil in the diet was increased.
Data are presented on the chemical composition of chaya leaf meal (CLM) (Cnidoscolus aconitifolius (Mill.) Johnston) and the availability of its amino acids to chicks.The crude protein, fat, ash, curde fibre and metabolizable energy contents were 296.2 g kg−1 dry matter (DM), 40.7 g kg−1 DM, 139.5 g kg−1 DM, 101.3 g kg−1 DM and 8.88 MJ kg−1 DM, respectively. CLM was relatively high in its content of calcium and iron. The sample contained anti-nutritional factors such as hydrocyanic acid and oxalate. No anti-tryptic activity was however detected in CLM.The amino acid composition of CLM indicates it is a good source of lysine and a fair source of sulphur-containing amino acids, cystine and methionine. The overall amino acid availability was moderately high (84.0%). With the exception of methionine and cystine, the amino acids in CLM had availability values > 80% and could therefore be regarded as moderately highly available.
Intestinal digestibilities of individual amino acids (AA), total AA and nitrogen (N) in three tropical protein-rich concentrates (sunflower cake, cotton seed meal and milkflow) and two legume forages (groundnut tops and cow pea tops) were estimated using the mobile bag technique with or without rumen pre-incubation for 16 h. For all feedstuffs the digestibilities of individual AA were close to total AA digestibility except for cystine and glycine which consistently showed the lowest digestibilities. However, the digestibilities of individual AA were different for different feeds. Rumen pre-incubation did not significantly influence the total AA digestibility within the examined feeds. Digestibility of total AA in the intact protein varied between 0.724 and 0.865 for legume forages and between 0.894 and 0.951 for concentrates. Using rumen pre-incubation the digestibilities of total AA varied between 0.749 and 0.826 for legume forages and between 0.897 and 0.956 for concentrates. There was no systematic deviation between total AA and N digestibilities. Sunflower cake showed the highest digestibilities of individual AA, total AA and N compared to other feeds while cow pea showed the lowest digestibilities of AA, notably cystine, lysine, methionine and proline. Milk flow had a low AA content (75.4 g AA/16 g N) implying use of low quality ingredients during feed formulation.
This paper examines the possibility of using palm kernel meal to replace groundnut cake in poultry diets. Palm kernel and groundnut cake samples were compared in terms of chemical composition, amino acid content and amino acid availability to chickens. Palm kernel meal samples showed deficiencies in more of the essential amino acids than the groundnut cake. While the overall amino acid availability value for groundnut cake (91.1%) was significantly (P < 0.05) higher than that of palm kernel meal (83.3%) most of the amino acids in palm kernel meal except valine, glycine and proline had availability values greater than 85% and could therefore be regarded as highly available. It appears that for palm kernel meal to effectively replace groundnut cake in poultry diets, it needs to be combined with other protein sources in order to increase dietary levels of some of the deficient amino acids.
The effect of several additives on fibre (DF) and starch fermentation in the rumen in vitro was studied. A series of incubations, (24 h) with rumen fluid and DF-hay (hay washed with detergent) or soluble starch as the sole substrate was performed. The following compounds were investigated at a final concentration of 8 ppm: Avoparcin, Lasalocid, Monensin, Capreomycin, Flavomycin, Thiopeptin, Novobiocin, Virginiamycin, Terramycin, Aureomycin, Salinomycin, Bacitracin and a deaminase inhibitor dimethyldiphenyliodoniumchloride (DDIC).All additives, except Capreomycin, Flavomycin, DDIC, Avoparcin and probably Bacitracin inhibited volatile fatty acid (VFA) production in DF-hay incubations. Virginiamycin and the ionophores were the most potent inhibitors of fibre degradation. In starch incubations, different drugs had different effects on VFA production, as increases, decreases or no effects at all were found. For instance, ionophores and Bacitracin increased VFA production, in contrast with tetracyclines and Novobiocin, while Thiopeptin, Avoparcin, Capreomycin and Flavomycin had no effect. The effect on VFA proportions is also reported and discussed.It was clear that, with the exception of DDIC, antibiotics inhibiting protein (casein) degradation also lowered DF degradation. No such relation was observed between caseinand starch breakdown. It seems that only DDIC was a specific inhibitor of protein degradation.
Four strains of Piromyces isolated from the rumen of fistulated sheep and cattle and from the caecum of fistulated donkeys and ponies were compared for their ability to grow on glucose and cellobiose, to digest cellulose and for the end-products of their fermentation.Two main differences appeared between the ruminal and caecal fungi. The equine strains grew more rapidly than the ruminal strains on glucose and cellobiose and did not produce lactate. The four strains had a typical mixed-acid fermentation. The ruminal strains mainly produced formate, acetate, lactate, ethanol and the equine strain produced only formate, acetate and ethanol. Small amounts of malate and succinate and traces of fumarate were also detected. The donkey strains degraded cellulose more rapidly and to a greater extent than the other strains.
Six samples of six different varieties of sorghum (Bianco, Rosso I, Pau, Argence + Rosato, Rosso II and Argor) varying in their tannin content (1.6, 4.3, 2.2, 3.1, 9.2 and 40.1 g kg−1 of catechin equivalents, respectively) were used in diets formulated for piglets weaned at 21 days of age to test their effect on growth and digestibility.In Experiment 1, 18 weanling castrated male and 18 weanling female crossbred Pietrain × Large White pigs were penned individually and randomly assigned in a complete block design to one of the three diets based on maize, Bianco or Rosso I sorghum varieties from 7 to 25 kg live weight. Animals were fed either on maize or only one sorghum diet (Pau) between 25 and 50 kg live weight and the same control diet from 50 kg to 100 kg live weight. Significant effects on growth performance among diets were only found in the growing phase, when daily weight gain was 510 and 467 g (P < 0.05) for animals receiving maize and sorghum based diets, respectively. As a consequence a reduction in growth performance of animals fed on sorghum (P < 0.10) for the overall period was been observed. No residual effect of sorghum tannins was observed on carcass composition.In Experiment 2, thirty weanling castrated males were used to determine total tract (28–35 days of age) and ileal (42–56 days of age) apparent digestibility coefficients of dietary components of four diets containing either maize or sorghum. Total tract apparent digestibility coefficients (TTAD) for energy and nitrogen, respectively, were similar for maize (90.7 and 88.2%) and low tannin sorghum diet (Argence + Rosato: 90.9 and 86.9%), both being significantly higher than the medium (Rosso II: 87.9 and 83.7%) and high (Argor: 86.7 and 81.0%) tannin sorghum varieties. A significant depressive effect of tannins (P < 0.05) on the ileal apparent digestibility coefficient (IAD) for energy was observed, 85.1, 85.8, 81.9 and 83.2%, and there was also a similar trend for nitrogen, 77.3, 78.3, 74.7 and 75.2%, respectively for the same four diets. Thus TTAD and IAD of energy and nitrogen were affected by tannin levels exceeding 2.5 g kg−1 in the diet.Chymotrypsin (P < 0.05) and lipase activities measured in the pancreas after slaughter at 56 days of age were increased and trypsin activity was reduced by an increase in tannin content in the diet. In the intestinal mucosa, the activities of maltase and γ-glutamyl transferase were adversely affected by the presence of tannin but peptidases or alkaline phosphatase activities were unchanged. The lower activity of proteolytic enzymes in the pancreas (trypsin) and brush border (γ-glutamyl transferase) could explain the lower digestibility of nitrogen in the small intestine and, consequently, in the total digestive tract.
Ten batches of brewers yeast slurry (BYS) were analysed for proximate chemical composition, then mixed with ground maize grain (GMG) at 1:2, 1:1.5 and 1:1 w/w ratios; and with cassava root meal (CRM) and cassava peels meal (CPM), both at 1:1 w/w ratio. The mixtures were sun-dried to moisture content of 100 g kg−1 or less, then packed and stored. The mean dry matter (DM) and crude protein (CP) contents of the BYS were 159.5 g kg−1 and 456.0 g kg−1 of DM, respectively. The mixtures of BYS:GMG at 1:2, 1:1.5 and 1:1 w/w contained 122.6 g, 135.6 g and 145.6 g kg−1 CP dry weight, respectively, while the BYS:CRM and BYS:CPM mixtures contained on average 86.5 g and 117.8 g kg−1 CP dry weight, respectively.The BYS:GMG mixtures at 1:1.5 and 1:1 ratios were included in diets to replace respectively 400 g kg−1 (BYS:GMG-1) and 550 g kg−1 (BYS:GMG-II) of protein supplied by 200 g kg−1 of soyabean meal in the control (GMG) diet. Eight crossbred weaner pigs of Large White and Landrace breeds averaging 11.78 kg liveweight, were allocated in groups of four, and in two replicates, to each of the three test diets for a 35 day feeding trial. Mean daily gain was 0.43 kg, 0.42 kg and 0.40 kg, mean daily feed intake was 1.03 kg, 0.95 kg and 0.96 kg, the feed gain ratio was 2.59, 2.35 and 2.39 for GMG; BYS:GMG-I and BYS:GMG-II diets, respectively. These values did not differ significantly (P > 0.05). Brewers yeast slurry reduced feed cost per kilogram liveweight gain significantly (P < 0.05) and improved feed utilisation with consequent improvement in pig production efficiency.
Conventional methods to assess total tract apparent digestibility and total mean retention time (MRT) in horses are based on a total collection of faeces during 5 or 6 consecutive days. The objective of this study was to assess some adaptations to these methods when applied to athletic horses, in order to minimize disturbances in their management and training schedule. The impact of a reduction of the collection period on both total tract apparent digestibility coefficients and MRT was evaluated. The reliability of acid insoluble ash (AIA) and lignin(sa) as markers for digestibility measurements and of a partial collection for liquid and solid phase MRT measurements was also examined, in comparison with the results obtained from total faecal collection. Six Arabian horses in endurance training, fed 8.0 kg meadow hay and 5.2 kg pelleted feed daily, were used. The total tract apparent digestibility of dry matter (DM), organic matter (OM), neutral detergent fibre (aNDFom), acid detergent fibre (ADFom) and hemicelluloses was measured from a total collection and a partial collection of faeces using AIA and lignin(sa) as markers, for 3-, 4- and 5-day collection period. Total MRT of Cr-EDTA, Eu-labelled hay and Yb-labelled concentrate was calculated using two algebraic methods based on the quantity or the concentration of excreted markers, for 1, 1.5, 2, 3, 4 and 5 days collection periods. The digestibility coefficients obtained with a total faecal collection were not affected when the collection period was reduced to 4 or 3 days, for DM, OM and the different fibre fractions of the diet. When lignin(sa) was used as a marker, reducing the sampling period to 3 days did not affect the digestibility coefficients of any of the constituents, and total tract apparent digestibility coefficients were under-estimated (P<0.001) in comparison to those obtained by total faecal collection. When AIA was the marker, total tract apparent digestibility coefficients were lower (P<0.05) with a 3-day collection period, than with 4- or 5-day period and the digestibility coefficients were over-estimated (P<0.01) in comparison to those obtained by total faecal collection. A spot sampling faecal collection of faeces vs. a total faecal collection led to the same MRT values for both solid and liquid phases. A 1.5-day faecal collection led to the same MRT values as a 5-day faecal collection, whatever phase (liquid or solid) was considered. However, due to horses reactions to experimental conditions, a minimum faecal collection period of 3 days is recommended for assessing total MRT.
Seventy-two weanling pigs, 28 days of age, were fed diets containing 0, 1%, 3% or 6% Jerusalem artichoke (JA) meal for 4 weeks. Total feed consumed and feed efficiency were significantly (P < 0.059) affected by the addition of JA to the diet. The pigs eating the diets containing JA had significantly (P < 0.05) increased concentrations of six volatile fatty acids (VFA) in their manure; animals receiving the 3% JA diet had the highest VFA levels with the exception of valeric acid. The smell of fresh (less than 4 h) manure from the pigs eating 3% or 6% JA was significantly (P < 0.005) sweeter, less sharp and pungent (P < 0.01), and had less of a skatole smell (P < 0.001) than pigs eating the 0% control diet. The manure from pigs eating JA was also judged to be lighter in colour with significantly (P < 0.001) more brown and green but less yellow colour.
Twenty-one Awassi lambs (initial body weight 20.4±0.4 kg) were used in a completely randomized design to evaluate the effects of adding ruminally protected fat (Ultralac™ 100) to fattening Awassi lambs diets on nutrient intake, digestibility and growth performance. Lambs were fed ad libitum three isonitrogenous high concentrate fattening diets that contained: (1) no added fat (CON); (2) 2.5% added fat (LF); and (3) 5% added fat (HF). Dry matter (DM) intake was higher (P<0.05) for the CON diet than the HF diet and intermediate for the LF diet. Ether extract intake was higher (P<0.05) for the HF (66.7 g per day) diet than for the LF (58.7 g per day) and the CON (20.7 g per day) diets. Metabolizable energy intake was not affected by the dietary treatments (average=10.7 MJ per lamb per day). Dry matter digestibility was higher (P<0.05) for the HF and LF diets (average=76.1%) than for fed the CON (65%) diet. Digestibility results for CP, NDF and energy followed similar patterns to that observed for the DM, although ether extract digestibility was higher (P<0.05) for the HF diet versus the CON and LF diets. There was no difference in weight gain for lambs fed the three experimental diets. There are no advantages to using protected fat in high concentrate fattening diets for Awassi lambs, since the reduced dry matter intake negated the increased dietary energy density.
Untreated and sulfur dioxide-treated wheat straw (WS) were used as additives for ensiling low dry matter (DM) lucerne in laboratory silos. The negative control (L + WS) consisted of 60% lucerne + 40% untreated WS on a DM basis. SO2-treated WS was added to the lucerne at 2 levels: 40% (L + 40% TWS) and 50% (L + 50% TWS) of the mixture DM. Lucerne wilted to reach the DM content of the above-mentioned mixtures (30%), was ensiled and served as the positive control (WL). Silos were opened after 90 days and the silages subjected to analyses. The highest DM loss (∼ 10%) was in the negative control (L + WS), whereas in the L + TWS silages DM loss was reduced to 0.5–4%. Lactic acid production was lower in the negative control (L + WS) because of the lack of fermentable sugars and in the L + 50% TWS because of the initial low pH of the mixture at ensiling (4.3). The greatest ability to preserve forage protein was found in the L + 50% TWS, in which nearly 80% of the protein was recovered after 90 days of fermentation, as compared with 43% in the L + WS and WL silages. Threonine and the basic amino acids were extensively degraded in the L + WS silages. The recovery of those amino acids was significantly higher in the L + TWS silages. Generally, the L + 50% TWS was the most successful treatment in preserving the forage amino acids. The concentration of phenylalanine was remarkably increased in silages which underwent extensive protein breakdown (L + WS and WL). In view of its ability to preserve energy and protein, SO2-treated WS could be considered as a future silage additive for direct ensilage of high quality, low DM forages.
Because nutritive value of forages is variable, producers are encouraged to submit samples to commercial feed test labs for chemical analysis. The ADF content can be used to predict the energy content of forage. An appreciation for the analytical variability and the limitations of predicting energy content from ADF is needed to interpret feed analyses reports in terms of animal performance. While predictions of DMI from NDF are poor, the NDF content of forage should be used in diet formulation to ensure adequate fiber. To maximize milk yield and milk fat content, both dietary NDF intake (as a percentage of body weight) and energy intake must be maximized. Diets for high producing dairy cows should be formulated to obtain the highest possible concentration of NDF from forage in the diet, while meeting the requirement for energy density. This can only be achieved by maximizing forage quality.
Two experiments with adult sows were carried out to obtain data on the fermentation of wheat bran and alfalfa meal and on the effects of these feedstuffs on nitrogen turnover and bacterial protein synthesis. Wheat bran was provided at levels of 0 g, 225 g and 675 g per day and alfalfa meal was given in amounts of 0 g, 575 g and 1150 g per day both in addition to a basal diet covering maintenance requirements. Each treatment was carried out in eight replicates. Both supplements significantly impaired the digestibility of different carbohydrate fractions. The level of supply, however, had no effect on the partial digestibility of these carbohydrates as incorporated in wheat bran and alfalfa meal. A proportion of 40–46% of the non-starch polysaccharides from wheat bran and alfalfa meal was degraded which is similar to the level previously observed with purified cellulose. Fecal nitrogen composition was only slightly affected by the supplements, whereas the excretion of all nitrogenous fractions increased. With alfalfa meal, the fecal N per gram of N intake significantly increased at a cost of urinary N. Bacterial protein excretion per 100 g of fermented matter was 13 g, 20 g and 28 g for the basal diet alone, for wheat bran and for alfalfa meal, respectively. The values obtained with the supplements fall within the range estimated for the efficiency of microbial protein formation in the rumen of ruminants.
In two consecutive periods, pectin was supplied at levels of 0 and 334 g dry matter day−1 together with a semi-synthetic basal diet to 12 adult sows weighing 166 ± 17 kg. In addition to the pectin treatments, two different levels of thiamine, 0.66 and 2.57 mg day−1 were applied. Aliquot samples of the completely collected feces were analyzed for proximate principles, detergent fiber fractions and nitrogen fractions. In the urine, nitrogen and allantoin N were determined, while the urea content was measured in blood plasma.The pectin fermentation rate was determined by three different methods so as to account for 94–96% of pectin intake. A slight, non-significant decrease in the digestibilities of all analyzed fiber components of the basal diet occurred with pectin. The apparent digestibility of nitrogen was reduced by more than 20% at an almost constant true N digestibility. The increased fecal nitrogen excretion with pectin caused a reduction in protein retention to zero, and was composed of 82% bacterial nitrogen. The changes in the proteinaceous water-soluble fraction of fecal nitrogen indicated an increase in the excretion of endogenous proteins. Calculation of the content of metabolizable energy, by a standard formula estimated from the digestibilities of the proximate contents, was demonstrated to underestimate the true energy content of pectin severely, as evaluated from energy balance trials (5.9 MJ ME kg−1 instead of 10.5 MJ ME kg−1). This occurred because the additional energy excretion in the form of bacterial protein was incorrectly considered as a genuine metabolic energy loss. The efficiency of bacterial protein synthesis using pectin, as estimated by fecal excretion, was 7.4 g per 100 g of pectin fermented. The thiamine treatments did not affect any of the criteria.
Apparent digestible energy (DE) content of defatted (DFRB) Australian rice bran was assessed in rats and pigs, while the metabolisable energy (ME) content and the metabolisability of chemical components of DFRB and full-fat rice bran (FFRB) were assessed in mature cockerels and young chickens. The DE of DFRB was similar for rats and pigs (11.2 and 11.8 MJ kg−1, respectively) as was dry matter digestibility (0.65 and 0.66). The ME content of DFRB was significantly lower for cockerels and chickens than that of the two FFRB samples tested. With chickens, the ME of the two FFRB samples was also significantly lower (by 5.2 and 4.1 MJ kg−1) than with cockerels and this related directly to reduced apparent metabolisability of rice-bran crude fat. Coefficients of metabolisability of crude fat of the two brans in chickens were only 0.31 and 0.43, compared with 0.94 and 0.93 for cockerels in FFRB from the cultivars ‘Calrose’ and ‘Starbonnet’, respectively.
The aim of this study was to determine effects of ensiling whole crop maize with the bacterial inoculants Bonsilage mais flussig (BMF) and Lalsil Fresh LB (LFLB) on fermentation, aerobic stability and growth of lambs. Whole crop maize (288 DM g/kg) was ensiled with no additive, BMF or LFLB for 60 days in 1.5 l jars and 3 months in 210 l drums. To follow the fermentation dynamics during ensiling, 1.5 l jars were opened on days 0, 4, 10, 21 and 60 of ensiling for sampling and analysed for pH, water-soluble carbohydrates (WSCs), volatile fatty acids (VFAs), lactic acid, ammonia-N, dry matter (DM), organic matter (OM), metabolizable energy (ME), crude protein (CP), ether extract (EE), ADF and NDF. The aerobic stability of silage was determined by opening jars on day 60 and putting silage in an aerobic environment until day 65. After 3 months of ensiling the 210 l drums were opened, sampled and analysed as for the laboratory scale silos. Silages were fed to 24 South African Dorper lambs (n = 8/treatment) weighing 20.6 ± 0.62 kg to determine intake in a 63-day experimental period. Results from the small silos showed that the inoculants decreased (P<0.05) pH, butyric acid and ammonia-N while increasing WSC, lactic acid and acetic acid compared to the control silage. Aerobic stability of the silage was improved with inoculation as indicated by lower (P<0.05) CO2 production when compared with the control silage. Furthermore, the control silage showed a rise in pH and a changed decline in lactic and acetic acid concentrations when exposed to air, as compared to the inoculated silages. Inoculants did not affect DM, pH, OM, CP, ME, EE, ADF and NDF contents of the silage from 210 l drums. However, bacterial inoculants increased (P<0.05) WSC, lactic acid and acetic acid, while reducing butyric acid and ammonia-N compared to the control. Lambs fed the LFLB inoculated silage had higher (P<0.05) intakes of DM, OM and CP, higher final body weights and average daily gains (ADGs) compared to the other treatments. It was concluded that both bacterial inoculants improved fermentation dynamics and aerobic stability of whole crop maize silage, and improved lamb performance occurred when LFLB inoculated whole crop maize silage was fed.
Experiments were conducted to determine the nutritive value of selected cultivars of Canadian winter wheat. A 21-day growth trial was conducted in which 36 Sprague-Dawley rats (initial weight 53.4 g) were randomly assigned to one of six dietary treatments. The experimental diets contained one of the winter wheat cultivars Yogo, Sundance, Nugaines, Winalta and Kharkov, or casein. The diets were formulated to supply 10% crude protein by dilution of the test protein with varying levels of a proteindashfree diet. An additional 30 rats were utilized in digestibility studies. There were no significant differences in protein content (range 13.9–15.2%), concentration of indispensable amino acids or digestibility coefficients between cultivars of winter wheat. During the 21-day feeding trial, rats fed on the cultivar Nugaines consumed significantly (P < 0.10) more feed (255 g) than rats fed on the cultivars Yogo (213 g) and Kharkov (207 g). These differences in feed intake were reflected in daily gain, with rats fed on Nugaines gaining the most weight (45.7 g), followed by Sundance (43.2 g), Winalta (41.6 g), Yogo (37.9 g) and Kharkov (35.2 g). Performance of rats receiving the casein diet was approximately double that of the wheat-fed rats. This difference was not associated with feed intake, but was probably a reflection of the poor amino acid balance obtained from the winter wheat cultivars.
Digestibility determined by collection of feed residues at the terminal ileum (ileal digestibility) has been shown to provide a reliable estimate of amino acid availability to the pig. As a routine technique to collect ileal digesta, an ileo-rectal anastomosis (IRA) has been proposed. In this trial, four Large White pigs (52.0 ± 1.5 kg) were used to test IRA against ileo-colic post-valve fistulation (ICPV), considered as a reference fistulation technique. A standard cereal-based diet and two semi-synthetic diets enriched with either wheat bran or beet pulp were used. They were given consecutively to each group of two pigs (ICPV, IRA), once or twice a day, in the order mentioned above. Similar values for total nitrogen and amino acid-digestibility were obtained in ICPV and IRA pigs on the standard or the wheat bran diets. On the beet pulp diet, ICPV collection resulted in a significantly higher apparent digestibility of total nitrogen and amino acids than did IRA collection. This was probably due to the bypass of the ileo-caeco-colic sphincter in the IRA pigs. Therefore, depending on the diet, digestibility values based on IRA collection may differ from those measured by ICPV collection. Further work is needed to identify the particular conditions that make ileo-caeco-colic sphincter function a critical determinant of digestibility values.
Maize contributes approximately 65% of the metabolisable energy and 20% of the protein in a broiler starter diet and is by far the most commonly used cereal grain in the diets of intensively reared poultry. One reason for the widespread use of maize in the diets of farmed livestock is that there is a perception that maize is of a consistent and high nutritional value. However, recent studies have demonstrated that the chemical composition and nutritional value of maize is variable, making generic matrix values for maize inaccurate. The nutritional value of maize for poultry is a function of the content of starch, oil, protein and antinutrients (primarily phytate, enzyme inhibitors and resistant starches). The effect of these nutritional components and antinutrients on the nutritional value of maize are discussed as well as strategies to improve the nutritional value of maize for poultry.
The objective of this study was to determine whether dietary Ca concentration affects the ability to maintain Ca homeostasis in non-lactating non-pregnant dairy cows fed diets differing in dietary cation–anion difference (DCAD). Eight non-lactating non-pregnant multiparous Holstein cows (594 ± 80.3 kg body weight; 34.5 ± 11.4 month old) were fed diets Low or High in DCAD (−64 vs. 82 mequiv./kg dry matter, respectively) in combinations with Low or High dietary Ca concentration (3.0 vs. 9.1 g/kg of dry matter, respectively) in a duplicated 4 × 4 Latin square design with 14-d periods. On d 14 of each period, cows were subjected to an EDTA challenge that consists of an intra-jugular infusion of EDTA solution to decrease blood Ca concentration. In this protocol, the time required to recover to 90% of the pre-challenge blood Ca concentration was determined as recovery time. During the EDTA challenge, mean blood bicarbonate concentration was lower for cows fed Low-DCAD diets although mean blood pH was not affected by treatment, indicating that cows fed Low-DCAD diets had mild compensated metabolic acidosis. Feeding High-Ca diet shortened the recovery time (106 vs. 134 min; P=0.04) when DCAD was low, while Low-Ca diet shortened the recovery time (125 vs. 159 min; P=0.02) when DCAD was high. These results suggest that the optimum dietary Ca concentration to minimize the risk of hypocalcaemia in dairy cows is likely different depending on the DCAD value.
Anatomical and histological features affecting the degradation of stem tissues by ruminal microorganisms were examined in ‘Caucasian’, ‘Ganada,’ and ‘WW-Spar’ Old World bluestem grasses (Bothriochloa spp.). Tissue degradation and/or staining results revealed variation among cultivars in the degree of lignification of parenchyma, sclerenchyma, and epidermal cells. In both immature and mature stems, parenchyma and sclerenchyma cell degradation by microorganisms was rapid and extensive for Ganada as compared with Caucasian and WW-Spar. In general, Caucasian tissues were more resistant to degradation than WW-Spar. There also were differences in tissue composition and degradation as a result of stem maturity. Increased lignification in parenchyma cells was primarily responsible for a decreased rate and extent of degradation in older stem portions. The major difference in tissue composition among cultivars was found in older stems; WW-Spar had more vascular and less parenchyma tissues than Caucasian and Ganada. However, Caucasian had a greater percentage of xylem-metaxylem complex tissues than the other two cultivars. The amount of lignified tissues did not seem to be related strongly with rate and extent of tissue degradation. Instead, the data suggest that our previously reported differences in digestibility among the three Old World bluestem grasses could be attributed to differences in the degradation of their individual tissue types. Fungal attachment was greatest on mature tissues, hence, the rate and extent of degradation of lignified tissues may be associated with the colonization of fungi in mature stems. Also, there was minimal colonization of fungi on immature tissues suggesting that their degradation was primarily affected by enzymatic or direct involvement of bacteria.
A lack of feed resources has been identified as the major constraint in ruminant livestock production in the tropics. Although forages, such as grasses, legumes and tree forages and the agro-industrial by-products, such as palm kernel cake, are available in abundance, their utilisation as animal feeds are limited due to the presence of dietary factors which may affect the voluntary intake and the entero-hepatic function of the animals. These dietary factors include saponins and copper in the palm kernel cake, mimosine and tannin in the tree legume (Leucaena leucocephala), sapogenins (epi-sarsasapogenin and epi-smilagenin) in the Signal grass (Brachiaria decumbens) and indospicine in the creeping indigo (Indigofera spicata). Great economic losses through general unthriftiness, poor weight gain, inefficient production and death have been attributed to these dietary factors.
Five Yorkshire × Lacombe barrows (45 kg initial weight), fitted with a duodenal cannula ∼ 10 cm from the pyloric sphincter, were used to determine the influence of fineness of grind (mesh size of 0.5, 1.0, 1.5 or 2.0 mm), pore size (10, 48, 63 or 70 μm), sample size (0.5 vs. 1.0 g) and bag shape (2.5 × 4.0 vs., 2.0 × 5.0 cm) on the apparent digestibility of protein in soya-bean meal (SBM), meat and bone meal (MBM), and canola meal (CM) determined with the mobile nylon bag technique (MNBT). An additional six barrows were used to determine protein digestibility by conventional methods. Protein digestibility values, determined by conventional digestibility techniques, were 93.1 ± 0.3 for SBM, 79.1 ± 0.7 for MBM and 79.3 ± 0.6% for CM. With the MNBT, the digestibility of protein in SBM was lower (P < 0.05) when the sample was ground through a screen with a mesh size of 2.0 as opposed to 0.5, 1.0 or 1.5 mm. Fineness of grinding did not affect the protein digestibility of MBM. Protein digestibility was lower (P < 0.05) for all three feedstuffs when the pore size of the nylon bag was 10 μm as opposed to 48, 63 or 70 μm. Decreasing the sample size from 1.0 to 0.5 g increased the protein digestibility of SBM (P < 0.05) but not of MBM or CM. Bag shape had no effect on protein digestibility.
Two treatment methods, forage supplementation and chemical treatment, both potentially capable of improving cocoa-pod utilisation by ruminants, were evaluated. Supplementation with Gliricidia sepium at 1.0% body weight of cattle fed on a 50% cocoa-pod diet yielded no positive results. Feed intake [4.6 vs. 4.8 kg dry matter (DM) day−1], growth rate (0.37 vs. 0.40 kg day−1) and feed/gain (12.7 vs. 12.0) for control and test cattle were similar. Chemical treatment using solutions of cocoa-pod ash (CPA), a caustic material, was more successful. Rumen degradability of cocoa-pods treated with CPA — equivalent in alkalinity to 2 (P2), 4 (P4), 6 (P6) and 8 (P8) g NaOH per 100 g — was linearly improved (P > 0.05) with the DM, acid detergent fibre (ADF) and neutral detergent fibre (NDF) disappearance rates of samples treated with either NaOH or CPA of equivalent alkalinity being similar. Degradability of DM, ADF and NDF increased from 25, 12 and 7% (control) to 55, 44 and 45% for P6- and 55, 46 and 42% for P8-treated samples, respectively. Digestibility of DM in cocoa-pod-based diets also increased (P > 0.05) from 45 (untreated) to 55% (P8 treated) in sheep and to 60% in goats. Nevertheless, treatment with P8 reduced (P > 0.05) daily feed intake from 69 to 36 in sheep and from 48 to 42 g DM per kg W0.75 in goats. Feed intake was, however, normal for diets containing P6-treated cocoa-pods (67 and 61 g DM per kg W0.75 per day) for sheep and goats, respectively. The concentration of CPA for treating cocoa-pod should, therefore, not be greater than the P6 level (35 g per 100 g), which corresponds in alkalinity to 6 g NaOH per 100 g.
The most important factor influencing forage quality is herbage maturity. For example, a 1-week delay in harvesting of alfalfa (Medicago sativa L.) will decrease digestibility and crude protein concentration by about 20 g kg−1 and increase cell-wall concentration by approximately 30 g kg−1. Forage quality also is influenced by the environment in which forages are grown and by soil fertility and these cause year-to-year, seasonal, and geographical variation in forage quality even when herbage is harvested at the same stage of maturity. High temperatures normally increase rate of plant development and reduce leaf/stem ratios and digestibility. Moderate water stress usually delays plant maturation and causes forage quality to be maintained at higher levels. Excessive amounts of forage protein nitrogen may be excreted as urea in animal urine, which can limit animal production. Protein in forages with high ruminal escape is used more efficiently. The amount of escape protein is higher for red clover (Trifolium pratense L.) than for alfalfa or white clover (Trifolium repens L.). As animal production continues to improve through genetic gain, the need for high quality forages will become more important. There is good potential for producing new cultivars with improved forage quality and several are now on the market. Additional cultivars with improved forage quality will be available in the near future.
Two experiments were performed to evaluate Lupinus albus cv. Hamburg as a source of protein for growing pigs. The first was in a factorial design, involving two levels of feeding (restricted and ad libitum) and five isocaloric, isonitrogenous diets (0, 10.3, 20.7 and 31% Hamburg, and 31% Hamburg supplemented with 0.20% synthetic L-lysine). The growth performance of pigs from 22 to 70 kg live weight was unaffected by 10.3% Hamburg replacing soya-bean meal and meat and bone meal, but at higher levels both growth rate and feed conversion efficiency were significantly depressed. Feed intake was not significantly affected by the level of Hamburg, but dressing percentage decreased significantly from 84.3 to 80.2% as the proportion of Hamburg was increased from 0 to 31%. The addition of synthetic lysine to the 31% Hamburg diet improved feed conversion efficiency, but not to the level of the diet containing no Hamburg.Hamburg contained 2100 mg/kg manganese and the effects of levels of manganese from 72 to 1330 mg/kg on pig performance between 20 and 55 kg live weight were studied in the second experiment. Up to 1330 mg/kg manganese in the diet did not affect the growth performance or carcass quality of pigs. In both experiments, the growth performance of pigs given 31 or 33% Hamburg diets, each supplemented with 0.20% synthetic L-lysine, was lower than that of pigs receiving diets without Hamburg.The digestible energy content and alkaloid content of Hamburg were 18.2 (SE ± 0.38) MJ/kg dry matter and 0.018%, respectively.
While trying to develop a most probable number (MPN) selective medium for the enumeration of Ruminococcus albus 7 and Ruminococcus flavefaciens B1a in coculture, it was observed that when cultures of the two organisms were mixed for testing the media, growth of R. flavefaciens B1a was inhibited. Subsequent studies indicated that R. albus 7 produced an inhibitory substance that was present in cell-free culture filtrates and the extent of inhibition increased with the quantity of R. albus filtrate. R. albus, MO2a and MO3g were also tested for inhibitory activity against R. flavefaciens B1a, B34b, R13e2 and C1a, Fibrobacter succinogenes S85 and Butyrivibrio fibrisolvens H17c. R. flavefaciens B1a and C1a were found to be inhibited by all strains of R. albus and strain B34b was inhibited by R. albus MO2a and MO3g. The inhibitory substance(s) was heat-labile and destroyed by protease. When R. albus strains were cocultured with a proteolytic organism isolated from the rumen, B. fibrisolvens H17c, inhibitory activity was decreased or completely destroyed. These results suggest that the inhibitory material is proteinaceous and may be a bacteriocin-like compound.
The nitrogen balance and growth performance of piglets (12–14 kg initial body weight) were measured to evaluate the nutritive value of meal from Lupinus luteus cultivars ‘Amulet’ and ‘Cybis’, Lupinus albus cultivar ‘Hetman’, Lupinus angustifolius cultivar ‘Saturn’ and a commercial batch of lupin seeds from Australia (ALS). The inclusion level of lupin seed meal in the barley-based diets ranged from 310 to 410 g kg−1 to provide 120 g of crude protein from each lupin species per kilogram of diet.The average apparent total tract digestibility of dry matter (0.91) and crude protein (0.90) in L. luteus diets was as high as in the control (soybean) diet. The lowest (P < 0.05) digestibility of dry matter (0.86) and crude protein (0.83) was found for the diet containing seed meal from L. albus.Utilization of the apparently digested nitrogen (nitrogen retained as a proportion of nitrogen digested) was highest in the soybean group and both groups with L. angustifolius (‘Saturn’ and ALS) with values of 0.71, 0.72 and 0.71, respectively. Intermediate values were found for L. luteus (‘Amulet’, 0.68; ‘Cybis’, 0.68) and the lowest (0.55) for the L. albus group.The growth performance of pigs given diets with seeds of L. luteus and L. angustifolius was not different from that of pigs given the soybean diet, but pigs given the L. albus diet had a higher (P < 0.05) feed conversion ratio.It was concluded that L. albus cultivar ‘Hetman’ was less suitable than other varieties as a source of supplementary protein for young growing pigs when included in the diet at the level of 37 g kg−1. Seeds of L. luteus cultivar ‘Cybis’ and both cultivars of L. angustifolius were used at levels of up to 41 g kg−1 in diets without depression of growth performance as compared with soybean diet.
The objective of the current study was to compare the digestible energy (DE) contents of maize, oats and alfalfa meal between European wild boar (Sus scrofa L.) and the domestic pig (S. scrofa domesticus, Landrace × Large White). Six pure wild boar (S. scrofa L.) and six domestic pigs (Landrace × Large White) with liveweights (mean ± S.E.M.) of 26 ± 0.6 and 21 ± 1.1 kg, respectively, were fed diets at a daily level of 0.10 × metabolic body weight (W0.75). The diets included a base diet and three experimental diets containing 700 g basal diet/kg and 300 g maize, oats or alfalfa meal/kg; all animals received all four diets. Chromic oxide was used as indigestible marker. The animals received each diet for an 8-day period with fecal samples collected on days 6, 7 and 8. The DE content of the maize, oats and alfalfa was calculated for each ingredient and statistically compared between the wild boar and domestic pig. For the maize and oats, there was no significant difference in the DE values between the domestic pig and wild boar. However, the DE value of the alfalfa was greater in the domestic pig (10.56 MJ kg−1 DM) than in the wild boar (8.48 MJ kg−1 DM). For ingredients that contain relatively low concentrations of fibre (such as maize and oats), it appears that DE values determined in the domestic pig can be validly applied for diet formulation for wild boars; however, for ingredients with higher fibre levels, the DE values in wild boar appear to be lower than those in the domestic pig.
Alfalfa forage was cut with a swather (3.048 m wide) at two stages of maturity (latevegetative or early-bloom). Drying forage was treated with three levels of simulated rain (0, 5 or 20 mm) applied with a sprinkler irrigation system at 24 or 48 h after cutting. Otherwise, the forage dried under clear skies with only a slight breeze and temperatures ranging from 15 to 34°C. Air-dry hay was baled when it had regained sufficient water from evening dew to prevent leaf loss. Chemical composition of untreated forage or hay taken immediately after swathing, before sprinkling, before baling and before feeding did not significantly differ. Plant cell wall constituents (CW) of undamaged hay increased from 38.1 to 41.6% (P < 0.001) by 1 week advancement in maturity. The 20-mm simulated rain increased CW from 39.4 to 43.6% (P < 0.001) by leaching out soluble constituents. Crude protein content of the hay did not change, but the simulated rain reduced (P < 0.05) available carbohydrate from 27.3 to 24.3% , total lipid from 5.8 to 5.2% and soluble ash from 9.5 to 9.0%. The CW content was used to estimate loss of yield and nutrients from measurements of rainfall on drying hay. Estimated yield loss from soluble nutrients was 9.7%. This consisted of losses of 18.8% available carbohydrate, 10.2% of crude protein, 19.8% of lipids and 14.0% of soluble minerals. Hay quality was reduced more by rain damage than by advancement in maturity.
Whole crop third cut alfalfa, brown mid-rib (bmr) corn, and corn were chopped and inoculated with one of four microbial inoculants used. Uninoculated silage was the control treatment. Each crop was ensiled in four mini-silos (1 L glass jars) per treatment. All silos were fermented for 60 days at room temperature (22 °C), and then they were opened and analyzed for fermentation products, fiber constituents and N fractions. A fraction of wet silage was ground with a blender for 30 s. In vitro gas production was measured in 160 ml sealed serum vials at 3, 6, 9, 24, and 48 h using the wet ground silage. At 9 and 48 h, rumen fluid was analyzed for volatile fatty acids (VFA) and microbial biomass yield (MBY). In all the three crops, the four inoculants produced only minor changes in pH and fermentation products during ensiling. Of the variables measured, soluble nonprotein N fractions were the characteristics most often affected by some inoculants. At 9 h incubation, in vitro gas production and VFA did not differ between control and inoculated silages, but MBY did. Among crops, alfalfa and corn silages had higher MBY than did bmr corn silage. Among inoculants, three of the four inoculated silages produced more MBY than did control. At 48 h, alfalfa silage produced higher MBY than did corn or bmr silage, and two of the inoculated silages had more MBY than did the control. There was no inoculant by crop interaction. Results suggest that some silage inoculants are capable of altering rumen fermentation, even in cases where effects on silage fermentation are small, and that this effect may be linked to better preservation of crop protein during ensiling.
Steers fitted with esophageal cannulas were used in three trials to measure reduction of whole corn when fed at different moisture levels and with no roughage or with alfalfa hay (AH), alfalfa silage (AS), or AH with water added to increase moisture level to that of silage (AHH2O). Feeding roughage (Trial 1) with whole corn decreased (P<0.05) the amount of whole corn in the masticate by 44% (17.3% vs. 9.7% whole kernels) compared with feeding corn alone. Varying moisture level of corn from 12% to 26% did not affect the percentage of whole corn remaining in the masticate. On average, in Trials 2 and 3, feeding AHH2O as a roughage reduced the percentage of undamaged whole kernels (P=0.08) compared with feeding AS as the roughage source. When compared with AH and AS, feeding AHH2O as a roughage source appears to enhance chewing and increase particle size reduction of grain fed in high energy diets.
In 24 h in vitro incubations with 25 ml of buffered rumen fluid, four doses (0, 20.8, 41.6 and 83.3 mg) of a DHA-edible algae product, Aquagrow-DHA, were examined in combination with sunflower (20 mg) or linseed oil (20 mg). One treatment contained no Aquagrow-DHA, linseed or sunflower oil and one was supplemented with Aquagrow-DHA (166.6 mg) only. Addition of lard ensured that total fat content was constant among incubations. Increasing amounts of Aquagrow-DHA progressively inhibited CH4 to a maximum of 80% (P<0.001). Increased CH4 inhibition was accompanied by decreased acetate (P<0.001) and butyrate (P<0.001), and increased propionate (P<0.001) proportions, but also by depression of the short chain fatty acid (SCFA) production by 30% at the highest Aquagrow-DHA level (P<0.001). However, SCFA inhibition only occurred when the Aquagrow-DHA dose exceeded 41.6 mg and CH4 production was reduced by about 30% (P<0.05) at this dose. Inhibitory effects were linked to the amount of unesterified polyunsaturated fatty acids, particularly docosahexaenoic acid. Incubations under partial H2 atmosphere suggested that a direct toxic effect to rumen methanogens was caused by higher amounts of unesterified DHA (>41.6 mg Aquagrow-DHA/incubation) only, whereas suppression of rumen methanogenesis at lower doses seemed to be indirect through a lack of substrate. This indicates bacteria providing H2 to the rumen methanogens to be more sensitive to unesterified DHA than rumen methanogens.
Passage kinetics of labelled hay (ytterbium-169) and concentrate (cerium-141) given as single doses were obtained at the faecal and duodenal sites in early-weaned dairy calves frequently fed high-concentrate diets. Data were used to compare: (1) two algebraic (Faichney, Thielemans) and three modelling methods (Grovum and Williams, Ellis, Dhanoa) for calculating the mean retention time (MRT) of feed residues within the entire digestive tract (faecal curves) or stomach (duodenal curves), (2) partial MRT parameters derived from the three models applied to experimental data. Both algebraic methods provided similar whole MRT for hay and concentrate, respectively. Whole MRT obtained using the three models were not significantly different from Faichney MRT or from each other but were different from Thielemans' MRT at both sampling sites. When considering the partial MRT within compartments of the models, the MRT within the mixing compartment having the lowest turnover rate (referred to as MRT1) was found not to be different between models regardless of sampling site and ration constituent. Differences between models were apparent for MRT within the second compartment (MRT2) and for the transit time (TT). Thus, MRT2 estimates were not different between the Grovum and Ellis models but the Dhanoa model generated MRT2 values that were 50% lower, whatever the ration constituent and sampling sites considered. The lowest and highest estimates of TT were obtained using the Ellis and Dhanoa models, respectively, at both sites and for both ration constituents. Correlations between faecal and duodenal estimates of MRT2 were generally moderate (0.49 < r < 0.59) for concentrate and not significant for hay. No significant correlations were found between faecal and duodenal estimates of MRT2 whatever the comparison (sampling site, feed residue) considered.
A laboratory method for determination of fibres insoluble by cellulase is suggested as a routine analysis for cattle compound feeds with varying proportion and quality of chemically treated straw and other fibrous components, in order to measure whether actual energy content corresponds to that declared.By a two-step analytical procedure, the total fibre is isolated by boiling with neutral detergent solution for 1 h, which removes the readily soluble carbohydrates, proteins and fat. By incubation of the isolated fibre in a solution of buffers and a commercial cellulase reagent for 48 h at 40°C the digestible fibre is removed. The organic matter in the residue, which is termed cellulase insoluble fibre (CIF), is a measure of unavailable organic matter for ruminants.The CIF content, total NDF and proximate constituents were determined in 47 compounds of extreme properties. Compared with digestibility in vitro (IVDOM), more organic matter was dissolved by the CIF-analyses in highly digestible feeds and less in feeds with low digestibility (IVDOM + fat = 87 − 0.70 CIF).
Conjugated linoleic acid (CLA) reduced the level of C18:1(n − 9) and increased the level C18:0 in yolk, which in turn was associated with embryo mortality. C18:1(n − 9) was reported to play an important role in chick embryo development. Therefore, the objective was to determine if the reduction in the level of yolk C18:1(n − 9) was responsible for CLA-related embryo mortality. Eight chickens per treatment were fed diets containing 5 g/kg linoleic acid (LA), 5 g/kg CLA, 5 g/kg CLA plus 30 g/kg linoleic acid (CLA + LA) or 5 g/kg CLA plus 30 g/kg oleic acid (CLA + O) for 13 d. Chickens were artificially inseminated weekly. Eggs were collected daily, held at 15 °C for 24 h and then incubated. Hatched chicks were killed within 24 h and body and residual yolk weights were measured. For fatty acid analysis, three eggs from each treatment were collected on day 8. After the seventh day of feeding, embryo mortality was 100% in the fertile eggs from the CLA group. Overall hatch (%) in the groups LA, CLA + LA, and CLA + O was 98, 94, and 91%, respectively. After the seventh day of feeding, CLA levels in yolks from the groups LA, CLA, CLA + LA, and CLA + O was 0.4, 2.6, 2.1, and 1.7 g/100 g, respectively. The ratio of C18:0/C18:1(n − 9) of yolks from the LA, CLA, CLA + LA, and CLA + O was 0.3, 0.9, 0.9, and 0.3, respectively. Adding O to diet (CLA + O) prevented CLA-induced decrease in yolk C18:1(n − 9) and increase in yolk C16:0 and C18:0. While C18:1(n − 9) was actually decreased 50%, C18:2(n − 6) was increased 42% in the yolk from the group CLA + LA compared to the group CLA + O. Egg yolks from hens fed CLA group had lower level of C20:4(n − 6) than the LA group (1.3 and 2.1 g/100 g, respectively). The O (CLA + O), but not LA (CLA + LA) appeared to prevent CLA-induced retain yolk in hatched chicks. These data, in light of previous reports, suggest that CLA-related embryo mortality is not associated with specific fatty acids (i.e. C18:1, n − 9 and CLA), but is related to changes in the ratio of saturated to unsaturated fatty acids.
The objective was to investigate the forestomach fermentation characteristics and diet digestibility in alpacas (Lama pacos) and sheep (Ovis aries) fed sorghum-sudan or alfalfa at low altitude (793 m). Four 2-year-old alpacas (48 ± 2.3 kg) and four 2-year-old sheep (50 ± 1.7 kg) were used in a study designed as split-plot in two replicated 2 × 2 Latin square, respectively, for alpacas and sheep. The main plot was species (alpacas and sheep) and the subplot was forage source (sorghum-sudan and alfalfa). Diet consisted of 700 g kg−1 forage, which was either sorghum-sudan or alfalfa, and 300 g kg−1 corn-based concentrate (dry matter [DM] basis). The animals were housed in metabolism crates and were fed twice daily for 21 days of each experimental period, with 11 days of adaptation and 10 days of sampling. There was interaction between species and forage on total volatile fatty acid (VFA) concentrations. The concentrations of total VFA decreased by substitution of sorghum-sudan with alfalfa in both species, but the magnitude of the reduction was smaller in alpacas (−17%) than in sheep (−34%). The molar proportions of acetate and BCFA were higher, whereas those of butyrate were lower in alpacas than in sheep with similar proportion of propionate as well as ratio of acetate to propionate between alpacas and sheep. Replacing sorghum-sudan with alfalfa in the diet reduced the ratio of acetate to propionate due to the reduced proportion of acetate and increased proportion of propionate. Ammonia N concentration was about 28% lower in alpacas than in sheep, with no difference between the forages. Redox potential, forestomach pressure, osmolality and methane production were overall lower in alpacas than in sheep. There were no interactions of species with forage source on digestibilities in the total tract. The species had minimal effect on the total digestibilities of nutrients but digestibilities of fibre were lower with alfalfa than with sorghum-sudan diet. The results revealed not only the great differences in forestomach fermentation, but also the similarity of digestibility of nutrients in the total tract between alpacas and sheep at low altitude (793 m).
Growth of aquaculture throughout the world requires increased production of fish feeds. Increased production of fish feed will require increased quantities of feed ingredients, mainly protein sources. Most high-value species of fish raised by aquaculture are carnivores requiring feeds containing 400 g kg−1 or more protein, generally supplied by fish meal. World fish meal production is not expected to increase beyond current levels. This has stimulated research into alternatives to fish meal to supply protein in fish feeds, such as animal and fish processing by-product meals, oilseed proteins and concentrates, and protein concentrates produced from grains. Most alternate protein sources have one or more negative attributes that limit their use in fish feeds. One major concern is how the use of alternate protein sources affect the content of fish farm effluent water. Innovative research on reducing or mitigating the negative qualities of alternate protein sources is increasing the potential for their use in fish feeds and will help alleviate future demands for fish meal by the aquaculture industry.