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Nitrate and lipids have been recognized as effective dietary additives to reduce enteric methane (CH4) production. The objective of this experiment was to evaluate the effects of nitrate (NO3¯) and canola oil, alone or in combination, on enteric CH4, volatile fatty acid (VFA) concentrations, digesta kinetics and outflow of DM and microbial non-ammonia nitrogen (MicNAN) from the rumen of cattle. Four rumen-cannulated steers were used in the experiment which was designed as 4×4 Latin Square with four 21-d periods and four treatments. Dietary treatments consisted of a control diet (CON: 400 g/kg lucerne chaff and 600 g/kg barley grain), NO3¯ (CON+20 g NO3¯/kg), O (CON+50 g canola oil/kg), and NO3¯+O (CON+20 g NO3¯/kg + 50 g canola oil/kg)with all inclusions expressed as g/kg as-fed. Exogenous markers (Co-EDTA, Yb-acetate and 15NH4Cl) were continuously infused into the rumen over 4 d to estimate digesta flow and rumen N outflow while whole tract digestibility (DMD) was determined using chromic oxide. Compared with the CON diet, feeding the NO3 ¯+O diet reduced (P < 0.01) methane yield (MY, g CH4/kg DMI) by 25%, daily methane production (DMP, g CH4/d) by 26% (P < 0.01) and the rumen mean retention time (MRT; P < 0.05). Nitrate containing diets reduced DMD (P < 0.01). Total VFA did not differ between treatments (P > 0.05) but NO3¯-containing diets increased acetateproportion (P < 0.01) whereas feeding the O diet increased propionate proportion (P < 0.01). Oil-containing diets reduced rumen volume (P < 0.01). The rumen protozoa concentration was reduced by including NO3¯ and canola oil alone or in combination in the diet of cattle (P < 0.05). This experiment demonstrates that feeding NO3¯+O has a synergistic effect on reducing methanogenesis from beef cattle which is consistent with NO3¯ and canola oil having complementary mechanisms for suppressing enteric CH4 production. Reducing methanogenesis by feeding NO3¯+O in this experiment did not improve the flow of MicNAN from the rumen (g MicNAN/d), microbial growth efficiency (g MicNAN/digestible organic matter intake, DOMI) or the proportion of microbial N derived from rumen NH3. Estación Experimental Agropecuaria Bariloche Fil: Villar, Maria Laura. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; Argentina Fil: Hegarty, Roger Stephen. University of New England. School of Environmental and Rural Science; Australia Fil: Nolan, John V. University of New England. School of Environmental and Rural Science; Australia Fil: Godwin, Ian R. University of New England. School of Environmental and Rural Science; Australia Fil: McPhee, Malcolm J. University of New England. NSW Department of Primary Industries, Livestock Industries Centre; Australia more...

Some plants not only contain various nutrients which support the growth of animals, but also contain anti-nutritional factors which have adverse effects on animals. NPAAs, such as ODAP and DABA, are among those compounds. In addition to the direct adverse effects on animals by NPAAs, studies also have shown that ODAP, a major non-protein amino acid in some forage legumes, inhibited the growth of some non-ruminal microorganisms. Experiments were conducted to determine the effects of ODAP and DABA on in vitro dry matter (DM) digestibility of lucerne chaff as means to test their effects on ruminal microorganisms. The results showed the in vitro DM digestibility of lucerne chaff at 24, 48 and 72 h was significantly reduced by 18.6, 11.0 and 8.6% when three levels of ODAP (40.67, 81.34 and 122 μg/ml, C18 reverse phase chromatography-fractionated extracts from L. sativus ) were included in the medium. No inhibitory effect of diaminobutyric acid on in vitro DM digestibility of lucerne chaff was observed when pure DABA was used at a concentration of up to 300 μg/ml. The results indicated that although ODAP and DABA are similar in structure, they have different effects on ruminal organisms. Therefore, the use of DABA-containing plants as a feed supplement is not likely to cause any adverse effect on feed utilization, whereas the use of ODAP-containing plants may have some adverse effects on feed digestibility. more...

This study examined the effect of raw and roasted narbon bean (Vicia narbonensis) in a roughage-based diet on growth performance and meat sensory attributes of sheep. Roasting was examined to determine whether it improved protein utilisation. Lambs ([Border Leicester×Merino]×Poll Dorset; 6 months old, mean liveweight of 34.9 kg) were allocated to three treatments (n=8 per treatment): Nil, lucerne and oaten chaff; raw WNB (chaff plus raw whole narbon bean); and roasted WNB (chaff plus whole narbon bean roasted at 150°C for 45 min). Raw and roasted narbon bean supplied 56% of total protein (approximately 15% DM) and were fed for a period of 8 weeks. Growth performance was evaluated over 6 weeks followed by a 7 day nitrogen balance measurement in five lambs from each treatment. Remaining three lambs were maintained on their treatment diets and all lambs were slaughtered at the end of the nitrogen balance study after blood samples were taken. For Nil, raw and roasted WNB ADG was 84.3, 158.1 and 171.6 g per day; FCE 16.5, 7.7, 7.2 kg/kg DM and nitrogen retained 6.4, 6.9, and 8.3 g per day, respectively. At slaughter, HCW, was 18.5, 21.4, 22.3 kg; fat depth 12.6, 17.9, 17.6 mm, and dressing percentage 45.9, 49.9, and 51.4% for Nil, raw and roasted WNB, respectively. There was no significant difference between raw and roasted WNB for any performance trait. In contrast, all performance traits except for nitrogen retained were significantly (P more...

A total of 285 samples representing 51 feedstuffs used in Belgian feed-mills were quantitatively analysed for phytase activity, phytate-P and total P. It was concluded that the number of feedstuffs showing significant phytase activity (more than 100 units kg−1) is rather limited (n = 13). Of the cereals analysed, only rye (5130 units kg−1), triticale (1688 units kg−1), wheat (1193 units kg−1) and barley (582 units kg−1) were rich in phytase. Wheat by-products, such as fine bran meal (4601 units kg−1) or pellets (2573 units kg−1)], middlings (4381 units kg−1), feed flour (3350 units kg−1) and bran (2957 units kg−1) were very phytase rich. Pelleted wheat fine bran samples were, on average, only 56% as active as non-pelleted wheat fine bran. Malt sprouts pellets (877 units kg−1) as well as corn distillers (385 units kg−1) also showed a moderate phytase activity. All other feedstuffs analysed showed zero or extremely low phytase activity. Phytase activity was not related to total P content or phytate-P content. A significant linear relationship was found between phytate-P and total P, for two feedstuff classes—wheat plus wheat by-products (R2 = 0.953; RSD = 0.060) and maize plus maize by-products (R2 = 0.928; RSD = 0.042)—but not for cereals or oil meals. Phytate-P content, as a percentage of total P content, was higher in cereals and in wheat by-products than in oil-seed meals and legume seeds. In malt sprouts, corn distillers and moist ensiled maize, phytate-P seems to be totally or partly hydrolysed as a result of processing or ensiling. In feedstuffs derived from roots and tubers, as well as in citrus pulp, cocoa shells, soyabean hulls, flax chaff, maize cob meal, dehydrated alfalfa and a dried mycelium sample, phytate-P was not detectable. more...

The effects of a lucerne supplement and defaunation on feed intake, digestibility and N retention were studied in cannulated wethers given either an ammoniated wheat straw or an untreated wheat straw diet. Supplementation of the wheat straw diets with lucerne chaff (150 g day−1) significantly increased total dry matter (DM) intake from 520 to 715 g day−1 (untreated wheat straw) and from 615 to 815 g day−1 (ammoniated wheat straw). Intake of wheat straw was not significantly altered by the lucerne supplement. Defaunation of the wethers had no significant effect on feed intake. The rumen digestibility of untreated straw and ammoniated straw were measured using the nylon bag technique. Lucerne supplementation significantly increased the digestibility (% DM disappearance after 24 h incubation) of untreated wheat straw from 26 to 31% and ammoniated wheat straw from 39 to 43%. When defaunation was combined with lucerne supplementation the digestibility of untreated wheat straw increased from 26 to 33% and ammoniated wheat straw increased from 39 to 50%, indicating that the effects of these two treatments were additive. Lucerne supplementation significantly increased N retention in wethers fed either the untreated wheat straw diet or the ammoniated wheat straw diet and defaunation significantly increased N retention in the animals fed the wheat straw diet. In a second study, 64 crossbred lambs (32 faunated and 32 defaunated) were offered one of four dietary treatments. The dietary treatments were either wheat straw or ammoniated wheat straw supplemented with two levels of lucerne (0 and 150 g day−1). Daily feed intake, liveweight gain and wool production were measured over a 70 day period. Daily liveweight gain was significantly increased by lucerne supplementation (P more...

Experiments comparing the nutritive value of cereal straws from different genotypes are often complicated by the difference in plant height which is affected by genotype and the amount of rainfall. Two experiments were therefore conducted to study the morphological characteristics, chemical composition and rumen degradation of barley straw fractions from several genotypes over a range of watering levels. The range was obtained by using sprinklers to apply various levels of water in addition to normal rainfall. In Experiment 1, there were four genotypes of barley and three levels of watering, and in Experiment 2, another three genotypes of barley and four levels of watering. Grain and straw yield, stem height, the proportions of chaff, leaf and stem, the chemical composition of these morphological fractions, and the dry matter losses (DML) of fractions from nylon bags placed in the rumen, were determined. The extent and rate of DML was estimated. In both experiments, applying additional water almost doubled stem height. The effects of watering level on grain and straw yield and plant morphological fractions were therefore generally greater than the effects of genotype. In Experiment 1, genotype and watering level had few significant effects on the chemical composition of straw fractions and in Experiment 2 chaff composition was generally affected by genotype, but both genotype and watering level usually affected leaf composition. Both genotype and watering level affected the extent of digestion of leaf in Experiment 1, whereas in Experiment 2 genotype was more important than watering level in affecting the extent and rate of digestion of stem. The results show that water stress can affect the composition and rumen degradation of barley straw to a similar extent as can genotype. This finding should be recognised when comparing cereal straw from genotypes harvested in different years and locations in semi-arid environments. more...

A modified inhibitor in vitro method was used to estimate the rate and extent of protein degradation in the rumen for casein, formaldehyde-casein, soyabean meal, cottonseed meal, peanut meal, sunflower meal, formaldehyde-sunflower meal, coconut cakes, lupin, oat and barley grains, lucerne (fresh and chaff), meadow hay, white and subterranean clovers. Degraded protein was determined by non-trichloroacetic acid precipitable nitrogen instead of the sum of alpha-amino nitrogen and ammonia nitrogen (as in the original method). Increasing the proportion of lucerne chaff in the lucerne chaff/oat grain diet of the donor sheep increased, within feeds, estimates of degradation rate ( k d ) and percentage degraded at a fractional outflow rate from the rumen ( k r ) of 0.05 h −1 . Degradation rate was markedly decreased when fresh lucerne was oven-dried at 100 °C, compared with the same material either (1) snap-frozen then freeze-dried or (2) oven-dried at lower temperature. Using nine feeds, a comparison was made between results from the in vitro and an in situ method. There were significant differences in estimates of several degradation parameters. Mean in situ estimates of k d and percentage degraded at k r = 0.05 h −1 were 79% and 94%, respectively, of in vitro estimates. Mean coefficients of variation for all parameters tended to be higher for the in situ method. In the absence of an absolute method for determining protein degradation, it is not possible to determine which of the two methods is more accurate. The limited incubation time precludes the use of the in vitro method for very slowly degraded feeds. However, this method is able to identify (1) significant differences between samples of the same feed type, (2) substantial effects of basal diet on degradation, and (3) heat damage to feed protein. more...

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. more...

A method of drying and then separating sugar cane stalks into three fractions is described. The three fractions, termed F1, F2 and F3, contained naturally occurring soluble sugars plus parenchymal cells (F1), sugars plus parenchymal cells and more fibrous tissues (F2) and even less soluble sugars and more fibrous rind tissues (F3). In Experiment 1, the three cane fractions were fed, with suitable supplements, to sheep to determine their metabolizable energy contents which were found to be 9.1, 8.9 and 8.7 MJ kg −1 DM, respectively. In the second experiment the total food intakes and live weight gains of lambs fed F1 with and without supplements of NaHCO 3 , lucerne chaff or oaten chaff were determined; F2 and F3 were fed with and without lucerne chaff. The lambs fed the F1 diet supplemented with oaten chaff performed slightly better than other supplemented groups (live weight gain 99 g per head per day). Weight gains of the lambs fed the F2-based diets with and without the lucerne chaff supplement were 65 and 34 g per head per day, respectively; both groups of lambs fed the F3-based diets lost weight. The third experiment examined the effect on food intake and live weight gain of treating the cane fractions (F1 and F2 only) with NaOH or pelleting the F1-based diets. Both treatments increased intake and rate of live weight gain, but the effects were not additive; NaOH treatment of the F1 diet resulted in an increase in intake from 35.1 to 41.3 g kg −1 W day −1 , whereas the intake of the pelleted F1 diet was 45.0 g kg −1 W day −1 . The corresponding rates of live weight gain were 110, 148 and 188 g per head per day. Adding rice polishings or cracked white rice to the F1 diets had a positive, but non-significant effect on animal performance. Lambs fed an NaOH-treated F2-based diet consumed 37.6 kg −1 W day −1 and gained 120 g live weight per head per day. The results show that the sugar cane fraction F1 can provide a major part of a sheep's diet and achieve good weight gains. These experiments indicate that similar results may be obtained if the cane fractions are fed to cattle or goats and this may be particularly relevant in tropical countries. more...

The hypothesis tested was that feed values of spring wheat crop residues could be improved by selection of cultivar, N fertilizer application rate and crop residue component harvested. Nine wheat cultivars were grown at two test sites in Saskatoon, each at fertilizer levels of 0, 56, 224 kgN ha−1. Proportions of leaf, stem, chaff and grain were obtained for each level. Significant cultivar differences were observed at each site for plant component yields. A significant increase in the proportion of leaf components and a significant decrease in the proportion of the grain components was observed as soil nitrogen levels increased. Crude protein contents of plant components varied significantly with both cultivar and fertilizer level. Significant differences in digestibility in vitro also existed among cultivars. Increasing fertilizer levels significantly improved the digestibility in vitro of the leaf but not of the chaff. The chaff and leaf components of all cultivars were considerably higher in feed value than the stem component. Chaff collection for feeding purposes would provide a feed much superior to straw if farm harvest systems ensured that a minimum of the stem component was included in the chaff. more...

In 5 experiments, the rate of disappearance of nitrogen from sunflower meal, rapeseed meal and lupin seed was measured using nylon bags suspended in the rumen of sheep eating a basal diet of lucerne chaff. The oil-seed meals were tested in their normal condition and after treatment with formaldehyde or after pelleting, or both. The lupin seed was tested after milling to 3 degrees of fineness. In a 6th experiment, test foods marked with chromium were used to measure their fractional out-flow rates from the rumen so that the degradation of protein in the rumen could be estimated. Formaldehyde treatment of the oil-seed meals reduced degradation from 0.80 to 0.15 for sunflower meal and from 0.72 to 0.19 for rapeseed meal, under conditions in which their mean fractional out-flow rate from the rumen was 0.0416 h−1. Pelleting the treated meals increased degradation to 0.31 and 0.41, respectively, but had no effect on untreated meals. Formaldehyde treatment and the pelleting of treated meal had similar, but smaller, effects on the disappearance of the non-nitrogenous dry matter in the meals. With respect to the degradation of protein in untreated meal, there was as much difference between two batches of sunflower meal as between either of them and rapeseed meal. Estimates of nitrogen degradation for coarse, medium and fine samples of lupin seed meal were 0.71, 0.79 and at least 0.90, respectively. more...