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Thirty-one strains of propionic acid bacteria were screened for their effects on methane production and volatile fatty acid concentrations using in vitro assays of rumen fluid from Norwegian dairy cows and a grass silage–concentrate mixture as substrate. Nine of 31 strains were further analysed for effects on substrate degradation. Propionic acid bacteria led to reductions of up to 20% in methane production. Seven strains stimulated volatile fatty acid production, and in their presence in vitro substrate degradation tended to increase (P

This study determined enteric methane (CH4) emissions, intake, and apparent total tract digestibility of diets varying in fibre digestibility and fat content. A Latin square design with two levels of fat [2.0% and 6.0% dry matter (DM); low and high] and two levels of fibre digestibility [low fibre digestibility (LFbD) or high fibre digestibility (HFbD)] was used. Higher dry matter intake (DMI) was observed (P −1, respectively), with no effect of fat. Fibre, DM, and organic matter digestibility were higher (P 4 (g kg−1 DMI, organic matter intake, neutral detergent fibre intake, and percent gross energy intake), with emissions being higher when fat was added to the HFbD than the LFbD diet. The CH4 emissions per kilogram of neutral detergent fibre (NDF) digested were higher (P 4 emissions as a proportion of DMI or NDF intake in diets differing in fibre digestibility.

Propionibacterium thoenii strain T159 (5 × 1011 CFU) were administered daily in the rumen of four Norwegian Red dairy cows. Total Propionibacterium in the rumen were substantially increased during ...

Dairy milk samples from 37 milk tours in 15 areas of Norway were collected during indoor feeding or on pasture in 2008 and analyzed with respect to 6 major elements (Ca, P, K, S, Na, Mg) and 28 trace elements (As, Ba, Be, Bi, Cd, Ce, Co, Cr, Cs, Cu, Dy, Fe, I, La, Li, Mn, Mo, Nd, Pb, Rb, Sb, Se, Sm, Sr, V, Y, Yb and Zn). Surprisingly, the least-square means of major and trace elements in milk did not vary much from one region to another. The concentration levels of iodine, copper, manganese and lithium in milk from the northern region were higher compared with milk from other regions. Milk from the south was enriched with respect to selenium, yttrium, cerium and bismuth, while milk from the western region was enriched with respect to rubidium.

The objective of this study was to determine the impact of ruminal pH on methane (CH4) emission from beef cattle. Ruminal pH and CH4 data were generated in 2 experiments using 16 beef heifers offered high-forage (55% barley silage) or high-grain (92% concentrate; DM basis) diets. Both experiments were designed as a replicated 4 × 4 Latin square with 4 periods and 4 dietary treatments. Methane was measured over 4 consecutive days using open-circuit respiratory chambers with each chamber housing 2 heifers. The ruminal pH of individual heifers was measured using indwelling pH loggers. The mean ruminal pH and CH4 emission (g/h) of 2 heifers in every chamber were summarized in 30-min blocks. Even though rumen methanogens have been described to be inhibited by a pH 0.05). Daily mean CH4 emission (g/d) and ruminal pH were only mildly correlated (r2 = 0.27; P < 0.05), suggesting that additional factors, such as increased propionate formation or passage rate, account for the lower CH4 emissions from cattle fed high-grain as compared to high-forage diets. Lowering ruminal pH alone is, therefore, not an effective CH4-mitigation strategy. Mechanisms permitting methanogens to survive episodes of low-ruminal pH might include changes in community structure toward more pH-tolerant strains or sequestration into microenvironments within biofilms or protozoa where methanogens are protected from low pH.

Meale, S. J., Ding, S., He, M. L., Dugan, M. E. R., Ribeiro Jr. G. O., Alazzeh, A. Y., Holo, H., Harstad, O. M., McAllister, T. A. and Chaves, A. V. 2014. Effect of Propionibacterium freudenreichii on ruminal fermentation patterns, methane production and lipid biohydrogenation of beef finishing diets containing flaxseed oil in a rumen simulation technique. Can. J. Anim. Sci. 94: 685–695. The objectives of this study were to examine the effects of Propionibacterium freudenreichii (strain T54; PB) and flaxseed oil (FO) in a total mixed ration on ruminal fermentation, CH4production and fatty acid biohydrogenation in two artificial rumens (RUSITEC). The experiment consisted of 8 d of adaptation and 12 d of sample collection with four replicate fermenters per treatment. Treatments were: (1) CON; (2) PB; (3) FO (60 g kg−1DM with autoclaved PB); (4) FOPB (60 g kg−1DM with PB). Disappearance of DM (g kg−1DM) and gas production (mL g−1DM) were not affected by treatment (P>0.05). Inclusion of FOPB increased (P=0.01) total volatile fatty acid (VFA) production (mmol d−1), compared with CON and PB. The acetate:propionate ratio was reduced (P−1DM or mL g−1DMD) was lowest (P4compared with CON. Fatty acid profiles for PB were similar (P>0.05) to CON for most fatty acids. Concentrations of 18:3n-3 were greater (P4production under the current conditions as a result of increasing propionate production.

Previous research has shown that feeding high fat corn distiller’ grains plus solubles (CDDGS; ∼10% fat, dry matter [DM]) reduces enteric methane (CH4) emission from beef cattle. However, feeding CDDGS (∼30% crude protein [CP] DM) or wheat distillers’ grains plus solubles (WDDGS; ∼40% CP, DM) increases N excretion from beef cattle and the resulting increase in nitrous oxide (N2O) from manure may offset any CH4 mediated decrease in greenhouse gas emissions (GHG). The objective of this study was to evaluate the impact of CDDGS and WDDGS inclusion on GHG emissions from beef cattle using a life cycle assessment (LCA). The LCA was conducted using primary data for diet composition, CH4 emission and N excretion generated in two studies using growing and finishing beef cattle. A representative model farm was simulated using the Holos GHG model (www.agr.gc.ca/holos-ghg), which included 40% DM CDDGS or WDDGS in growing and finishing feedlot diets. The simulation was made relative to the standard practice of using barley grain as the main supplemental energy source in western Canadian beef cattle diets (baseline scenario). Feeding CDDGS (14.98 kg CO2 equivalent [CO2e]/kg live weight) and WDDGS (15.41 kg CO2e/kg live weight) resulted in 6.2 and 9.3% higher GHG intensity compared to the baseline scenario (14.10 kg CO2e/kg live weight). Using high-fat distillers’ grains in the diet of feedlot cattle may decrease enteric CH4 emissions, but at high dietary levels it increases N excretion and results in a net increase in GHG emissions. To reduce environmental impact, dried distillers’ grains should not be included in the diet of feedlot cattle at a level that exceeds N requirements. Manure arising from cattle fed DDGS should be land applied at a level that matches the N requirements of the crop.

The main objective of this study was to elucidate the potential for prediction of enteric methane (CH4) emissions from dairy cows by using predicted rumen plus hindgut digested (fermented nutrients) and total tract digested nutrients (by using NorFor) as input variables. Twenty-one experiments (78 dietary treatments) were collected. The data-set was used to develop prediction models and to test their and extant models ability to predict enteric CH4 emissions. Models were compared based on mean squared prediction error and concordance correlation coefficient (CCC) analysis. Fermented nutrients did not predict enteric CH4 emissions adequately (CCC < 0.420). Including total digested (td) nutrients in the model [CH4 (MJ/d) = −2.13 + 1.64 tdOM (kg/d) −9.74 tdFat (kg/d) + 1.64 tdNDF (kg/d)] predicted enteric CH4 emissions more precisely (CCC = 0.733), and showed an improvement in the prediction of enteric CH4 emissions over the extant models tested.

Effects of plant-bound condensed tannin (CT)-containing sainfoin vs. CT-free alfalfa (or low-CT alfalfa-sainfoin mixture), plant stage of maturity, and their interaction on enteric methane (CH4) emissions, diet digestibility, and N excretion were studied, using 8 ruminally cannulated beef heifers in 2 sequential short-term experiments (Exp. 1 and 2). In Exp. 1, first growth legumes were harvested daily and offered fresh to heifers. Heifers were assigned to 100% sainfoin or 80% alfalfa:20% sainfoin (as-fed basis). Responses were measured at early (late vegetative to early bud; stage 2 to 3) and late (early flower; stage 5) stage of maturity. In Exp. 2, the same legumes were harvested from second growth (late bud; stage 4) and offered to heifers as hay; 100% sainfoin or 100% alfalfa. In both experiments, heifers were fed once daily at 1× maintenance. When fed as fresh forage (Exp. 1), sainfoin, compared with the alfalfa-sainfoin blend, had greater digestibility of OM (74.7 vs. 70.9%; P = 0.02), yet tended to have lower CP digestibility (73.2 vs. 77.1%; P = 0.059). There was no difference between fresh legumes for CH4 emissions [25.9 g/kg DMI ± 4.02 SE; 8.5% of gross energy intake (GEI) ± 1.26 SE; or 36.8 g/kg digested OM ± 1.75 SE]. The fresh legumes were more digestible at early, rather than at late, maturity and, consequently, enteric CH4 (27.4 vs. 24.4 g/kg DMI; P < 0.004; 8.9 vs. 8.1% GEI; P < 0.008) was greater at early, rather than at later, growth. When fed as hay (Exp. 2), sainfoin, compared with alfalfa, had greater digestibility of OM (60.5 vs. 50.3%; P = 0.007), lower digestibility of CP (64.2 vs. 68.8%; P = 0.004), yet there was no difference between the legume hays for CH4 emissions (22.4 g/kg DMI ± 1.29 SD and 7.1% GEI ± 0.40 SD). However, on the basis of OM digested, CH4 emissions were lower for sainfoin than alfalfa hay (44.3 vs. 59.0 g/kg; P = 0.008). Percentage of total N excretion in urine was less for sainfoin compared with alfalfa, both for fresh legumes in Exp. 1 (74 vs. 78%; P = 0.017) or hay in Exp. 2 (64 vs. 72%; P < 0.001), and increasing maturity lowered urinary N excretion. In conclusion, feeding CT-containing sainfoin partially shifted N excretion from urine to feces, but it had little impact on enteric CH4 emissions from beef cattle fed at maintenance as compared with feeding either 80% alfalfa:20% sainfoin (fresh forages) or 100% alfalfa (hay). Feeding fresh legumes harvested between the late vegetative to early bud stage, compared with harvested at the early flower stage, increased N excreted in urine as well as enteric CH4 emissions from beef cattle fed at maintenance.

The objectives of this study were to examine the impact of corn- or wheat-based dried distillers grains with solubles (CDDGS or WDDGS) on enteric methane (CH4) emissions from growing beef cattle and determine if the oil in CDDGS was responsible for any response observed. Effects of CDDGS or WDDGS on total N excretion and partitioning between urine and fecal N were also examined in this replicated 4 × 4 Latin square using 16 ruminally cannulated crossbreed heifers (388.5 ± 34.9 kg of initial BW). The control diet contained (DM basis) 55% whole crop barley silage, 35% barley grain, 5% canola meal, and 5% vitamin and mineral supplement. Three dried distillers grains with solubles (DDGS) diets were formulated by replacing barley grain and canola meal (40% of dietary DM) with CDDGS, WDDGS, or WDDGS plus corn oil (WDDGS+oil). For WDDGS+oil, corn oil was added to WDDGS (4.11% fat DM basis) to achieve the same fat level as in CDDGS (9.95% fat DM basis). All total mixed diets were fed once daily ad libitum. Total collection of urine and feces was conducted between d 11 and 14. Enteric CH4 was measured between d 18 and 21 using 4 environmental chambers (2 animals fed the same diet per chamber). Methane emissions per kilogram of DM intake (DMI) and as percent of GE intake (GEI) among heifers fed WDDGS (23.9 g/kg DMI and 7.3% of GEI) and the control (25.3 g/kg DMI and 7.8% of GEI) were similar (P = 0.21 and P = 0.19) whereas heifers fed CDDGS (21.5 g/kg DMI and 6.6% of GEI) and WDDGS+oil (21.1 g/kg DMI and 6.3% of GEI) produced less (P < 0.05) CH4. Total N excretion (g/d) differed (P < 0.001) among treatments with WDDGS resulting in the greatest total N excretion (303 g/d) followed by WDDGS+oil (259 g/d), CDDGS (206 g/d), and the control diet (170 g/d), respectively. Compared with the control diet, heifers offered WDDGS, CDDGS, and WDDGS+oil excreted less fecal N (P < 0.001) but more (P < 0.001) urinary N. Results suggest that high-fat CDDGS or WDDGS+oil can mitigate enteric CH4 emissions in growing beef cattle. However, to completely assess the impact of DDGS on greenhouse gas emissions of growing feedlot cattle, the potential contribution of increased N excretion to heightened NH3 and nitrous oxide emissions requires consideration.

Two experiments were conducted to evaluate the effects of increasing concentrations of glycerol in concentrate diets on total tract digestibility, methane (CH4) emissions, growth, fatty acid profiles, and carcass traits of lambs. In both experiments, the control diet contained 57% barley grain, 14.5% wheat dried distillers grain with solubles (WDDGS), 13% sunflower hulls, 6.5% beet pulp, 6.3% alfalfa, and 3% mineral-vitamin mix. Increasing concentrations (7, 14, and 21% dietary DM) of glycerol in the dietary DM were replaced for barley grain. As glycerol was added, alfalfa meal and WDDGS were increased to maintain similar concentrations of CP and NDF among diets. In Exp.1, nutrient digestibility and CH4 emissions from 12 ram lambs were measured in a replicated 4 × 4 Latin square experiment. In Exp. 2, lamb performance was evaluated in 60 weaned lambs that were blocked by BW and randomly assigned to 1 of the 4 dietary treatments and fed to slaughter weight. In Exp. 1, nutrient digestibility and CH4 emissions were not altered (P = 0.15) by inclusion of glycerol in the diets. In Exp.2, increasing glycerol in the diet linearly decreased DMI (P < 0.01) and tended (P = 0.06) to reduce ADG, resulting in a linearly decreased final BW. Feed efficiency was not affected by glycerol inclusion in the diets. Carcass traits and total SFA or total MUFA proportions of subcutaneous fat were not affected (P = 0.77) by inclusion of glycerol, but PUFA were linearly decreased (P < 0.01). Proportions of 16:0, 10t-18:1, linoleic acid (18:2 n-6) and the n-6/n-3 ratio were linearly reduced (P < 0.01) and those of 18:0 (stearic acid), 9c-18:1 (oleic acid), linearly increased (P < 0.01) by glycerol. When included up to 21% of diet DM, glycerol did not affect nutrient digestibility or CH4 emissions of lambs fed barley based finishing diets. Glycerol may improve backfat fatty acid profiles by increasing 18:0 and 9c-18:1 and reducing 10t-18:1 and the n-6/n-3 ratio.

Sixteen strains of propionibacteria were inoculated into in vitro ruminal incubations to evaluate their potential to reduce methane (CH4) production from concentrate and forage diets. Propionibacte...

Globally, methane emissions account for 40–45% of greenhouse gas emissions from ruminant livestock, with over 90% of these emissions arising from enteric fermentation. Consequently, enteric CH4 emi...

International audience; AbstractIn many Western countries, milk and dairy products provide both mineral and lipid fractions relevant to our health. The milk contents of these compounds are highly variable, and the identification of husbandry conditions leading to milks favourable for both mineral and lipid fractions is of interest. The aims of this study were to describe throughout the year the changes in bulk milk compounds and to relate them to husbandry practices. Ten compounds with nutritional requirements were selected: a minimum amount is required for Ca, Mg, P, Zn, vitamin A, n-3 fatty acids (FA), oleic acid and n-6 FA, and a maximum amount for trans FA and C12–14-16 FA. Milks and their associated husbandry practices were collected five times during 1 year from 74 groups of farms located in France, Norway, Slovakia and Slovenia. The Ca, Mg, P and Zn contents varied in different ways throughout the year and independently of each other. We showed the absence of milks with the highest contents in these four minerals simultaneously, but we identified groups of farms where milk had high content in Mg or in Zn. Positive links have been confirmed between grass-based-diets and milk n-3 FA content, maize silage-based-diets and n-6 FA content, and diets rich in concentrate and oleic acid content. These results showed that it was possible to identify husbandry conditions leading to milk favourable throughout the year for one or several compounds but not for all compounds considered in this study.

To evaluate the iodine (I) level in Norwegian milk, the I concentration was determined in 104 dairy tanker milk samples collected from 19 milk tours in different areas of Norway, throughout the year 2008. The I concentration in milk from indoor feeding was 122 µg L−1 and higher than in milk from the summer season, being 92 µg L−1. The weighted average mean I concentration throughout the year was 114 µg L−1 milk. The results showed that the I concentration in milk from the winter season 2008 has been reduced to nearly the half during the last decade, from 232 µg I L−1 in milk collected in the winter season in 2000. The I concentration in milk from the summer season is at the same level as a decade ago. The reason for the reduction in I in milk produced during the winter season is not known.

Summary The main objective of this study was to investigate the effect of excess cobalt (Co) on gene expression of stearoyl-CoA desaturase (SCD), fatty acid synthase (FASN), diacylglycerol acyltransferase 1 (DGAT1) and diacylglycerol acyltransferase 2 (DGAT2) of lactating dairy cows in relation to milk fatty acid profile. Seven multiparous cows of the Norwegian Red cattle breed (NRF) had their basal diet supplemented with 1.4 g Co as a 24 g/l solution of Co-acetate per os twice daily for 7 days followed by a 9-day depuration period. Udder biopsies were performed prior to the treatment period, after 1 week of treatment and immediately after the depuration period. Excess Co reduced the proportion of all cis-9 monounsaturated fatty acids and increased the proportion of 18:0 in milk. However, gene expression levels of SCD, DGAT1, DGAT2 and FASN were not significantly altered. Our results indicate that the effect of Co on milk fatty acid profile is mediated at the post-transcriptional level by reduced activity of SCD in the mammary gland. Potential mechanisms explaining how Co might reduce stearoyl-CoA desaturation are discussed.

The main objective of this study was to examine if cobalt (Co) reduces Δ(9) -desaturase indices in milk and blood lipids in sows. The experimental design consisted of a repeated measurement consisting of a pre-treatment period of a minimum of 9 days, a treatment period of 5 days and a post-treatment period of 6 days. Experimental animals consisted of 10 lactating sows; five sows had an intramuscular injection of 59 mg Co diluted in 5 ml 0.9% saline solution twice a day, whereas the other five had an intramuscular injection of 5 ml 0.9% saline solution twice a day as a control. Milk Δ(9) -desaturase indices for cis-9 18:1, cis-9 16:1 and cis-9 14:1 were significantly reduced (p < 0.0001) as a result of the Co-treatment, contrasting with the plasma Δ(9) -desaturase indices, which were unaffected. Potential mechanisms explaining how Co might reduce milk Δ(9) -desaturase indices are discussed. Moreover, the toxicological level of Co and potential implications of using Co-ethylenediaminetetraacetic acid as a liquid marker in digestibility experiments are addressed.

Summary The objective of this study was to determine whether intravenous infusion of Co affects levels of fatty acid desaturation products in bovine milk. Six cows were assigned to two replicated 3 × 3 Latin squares with 14-day periods. Treatment occurred on days 1 to 5 and depuration occurred on days 6–14. Two treatments were tested, the first consisting of per os supplementation of 3.5 g Co daily in the form of Co acetate and the second consisting of intravenous injection of 175 mg Co daily in the form of Co acetate diluted in saline solution. The third treatment was a control. Both Co treatments decreased cis-9 18:1 levels from approximately 18 to 14 g/100 g fatty acids, and increased 18:0 levels from 11 to 17 g/100 g fatty acids in milk fat (p

Three experiments were conducted to study effects of amylose/amylopectin ratios and starch particle size on ruminal digestion characteristics of barley starch using an automated in vitro gas production system. In Experiment 1, starch digestion characteristics were measured in 12 barley cultivars with different amylose/amylopectin ratios, both as milled grain and as purified starch isolated from the original grain samples. The same 12 cultivars, harvested 1 year later from the same locations, were used in Experiment 2. Gas production was measured in milled samples, and in neutral detergent fibre (NDF) extracted from the same samples. The objective of this approach was to estimate gas production from neutral detergent solubles (NDS) as an approximation of starch. This was done by subtracting the NDF gas curve from the total gas production curve. In Experiment 3, starch digestion characteristics were measured for large and small starch granules from nine of the original cultivars used in Experiment 1. The gas curves obtained were fitted to a three-pool Gompertz model, and the effective rate of digestion (kd) was estimated with a two-compartmental rumen model. In Experiment 1, the effective starch kd for milled barley and purified starch were 0.122 and 0.118/h, respectively. Barley cultivars with low amylose (LA) had a higher effective kd (0.148/h) compared with cultivars with normal amylose (NA) (0.115/h) and high amylose (HA) (0.102/h) (P=0.010). Results obtained with milled barley were supported by the purified barley starch sample results, but differences were smaller and only numerically different. In Experiment 2, the ranking of the amylose groups was consistent with those in Experiment 1 ( i.e. , LA > NA > HA) (P=0.096). However, these differences were not reflected in the effective kd for the NDS fraction (P=0.366). Thus, factors other than those related to starch per se , or other structural features, are apparently important. Barley cultivars in the LA group had a higher effective kd for aNDF (0.098/h) than did NA and HA barley (0.060 and 0.055/h, respectively). Thus, the effect of the amylose group on the effective kd for aNDF corresponded well with the milled barley results. The NDF fraction, directly or indirectly, has a clear impact on the ruminal digestion rate of barley starch. There was no difference in the effective kd for starch between the small (0.126/h) and large (0.129/h) starch granules.

International audience; The aims of this work were to elucidate the potential of using milk fatty acid (FA) concentration to predict cow diet composition and altitude of bulk milk collected in 10 different European countries and to authenticate cow-feeding systems and altitude of the production area using a data set of 1,248 bulk cow milk samples and associated farm records. The predictions based on FA for cow diet composition were excellent for the proportions of fresh herbage [coefficient of determination (R-2) = 0.81], good for hay, total herbage-derived forages, and total preserved forages (R-2 > 0.73), intermediate for corn silage and grass silage (R-2 > 0.62), and poor for concentrates (R-2 < 0.51) in the cow diet. Milk samples were assigned to groups according to feeding system, level of concentrate supplementation, and altitude origin. Milk FA composition successfully authenticated cow-feeding systems dominated by a main forage (>93% of samples correctly classified), but the presence of mixed diets reduced the discrimination. Altitude prediction reliability was intermediate (R-2

Mono-gastric animals and ruminants require cereal starch with different degradation characteristics because they degrade and utilize starch differently. Characteristics affecting starch digestion are the amylose/amylopectin ratio, proportion A-/B-starch granules, starch granule shape, crystallinity, lipid content, nature of the protein matrix surrounding starch granules and the overall architecture of the starch granules. These are all characteristics of cereal grain that can vary within species according to genotype, and can be manipulated through plant breeding. A large collection of barley mutants affecting the endosperm phenotype is available and constitutes an enormous potential resource to improve nutritive values of cereals tailored for different nutritional purposes. In the starchy endosperm, starch biosynthesis is characterised by a committed pathway of different enzyme classes, and all together 14 different isoform classes are found in higher plants with specific functions. A wide genetic variation in starch polymer composition could therefore be obtained by searching for mutations in these genes. However, while the starch biosynthetic pathways are well known, the biosynthetic pathway of -glucan and the accumulation in endosperm cell walls

Tässä tutkimuksessa selvitettiin in vitro -kaasuntuotantomenetelmällä eri ohralajikkeiden jyvien välisiäeroja solun sisällyksen ja kuidun sulatusnopeuksissa. Tutkimus tehtiin osana isompaa tutkimushanketta ja yhteistyötahona oli Norwegian University of Life Sciences. Kokeessa oli mukana 12 ohralajiketta (Alamo, Candle, Cindy, Cinober, Kinnan, Fager, Olsok, Thule, StS 2-11, SW 2904, Glacier ja HA-d). Ohranäytteet toimittivat Graminor AS (Bjørke, Norway) ja Western Plant Breeders (Bozeman, USA). Jyvät jauhettiin ja niistä määritettiin kemiallinen koostumus sekä eristettiin neutraalidetergenttiin liukenematon jäännös eli solunseinäaines sulatusnopeuden määrittämistä varten. Sulatusnopeudet mitattiin in vitro –kaasuntuotantomenetelmällä MTT/ERA:n laboratoriossa sekä jauhetuista jyvistä että niistä eristetyistä kuitunäytteistä. Menetelmässä rehunäytettä inkuboidaan kolmen vuorokauden ajan kasvatusliuoksessa, jossa pötsinesteen mikrobit pilkkovat rehunäytettä. Käymisessä syntyvän kaasun määrä mitataan 15 minuutin välein. Tallennetulta kaasukäyrältä rehunäytteelle saadaan ajan suhteen vaihtuva sulatusnopeus, josta edelleen lasketaan vakiosulatusnopeus huomioimalla virtauksen vaikutus pötsisimulaatiolla. Solunsisällyksen sulatusnopeus määritettiin laskemalla solunsisällysaineille kaasuntuotantokäyrä erotuksena kokonäytteen ja kuidun kaasuntuotantokäyrien välillä.Ohralajikkeiden välillä havaittiin tilastollisesti merkitseviä (p

The effect of treatment temperature, treatment time and glucose addition on digestibility of starch of barley grain and pea grain were studied in situ in non-lactating dairy cows, and the relationship between rumen degradation of starch (RDS) and protein was also determined. Ground barley and peas were heat-treated at 100, 125 and 150 °C for 5, 15 and 30 min with and without addition of glucose. Samples were incubated in the rumen for 4, 8 and 16 h using the in situ method, and rumen degradation of starch was measured. The total tract indigestible starch fraction (ISF) was measured on the 16 h rumen residues using the mobile nylon bag method. Heat treatment at 100 and 125 °C significantly decreased RDS of both barley and peas, and the RDS was higher after treatment at 150 °C than at 125 °C. Treatment time had a significant effect on RDS, but only at 100 °C in both feeds. The lowest RDS of barley after 8 h rumen incubation occurred at 125 °C and treatment for 30 min, which decreased RDS 34% units compared to untreated barley. For peas, the lowest RDS after 8 h rumen incubation was observed after treatment at 125 °C for 5 min, causing a reduction of 21% units compared to untreated peas. The ISF was significantly higher in untreated peas than in untreated barley (9% versus 0.1%). Heat treatment had no effect on the ISF in barley, while in peas the ISF was significantly increased after treatment at 100 and 125 °C, but decreased at 150 °C. Addition of glucose before treatment reduced RDS significantly in both feeds at two of three incubation times. Correlation evaluation showed that in both feeds RDS mimicked rumen degradation of protein after treatment at 100 and 125 °C, but not after treatment at 150 °C. Glucose addition increased the relationship between RDS and RDP in both feeds.

The main objective of this study was to investigate the effect of supplementing a pasture diet with crushed rapeseed on enteric methane (CH4) emissions from lactating dairy cows. The experiment was conducted as a crossover design using eight multiparous lactating Norwegian red dairy cows [(means ± s.d.) 548 ± 52 kg bodyweight, 38 ± 14 days in milk and 35 ± 3.7 kg milk/day, at the start of the experiment] maintained in two groups and fed two diets in two periods with the second period extended (18 days) to investigate the persistence of the CH4 response. Four of the eight cows were fitted with a rumen cannula with two cannulated cows assigned to each group. Cows were maintained on pasture (24 h/day) with access to 9 kg/day of concentrate containing 10% crushed rapeseed (RSC) or a control concentrate (CC). Dietary fat content was 63 g/kg dry matter for RSC and 42 g/kg dry matter for CC. The CH4 production was measured for five consecutive days in each period using the sulfur hexafluoride tracer gas technique. Compared with CC, RSC caused a reduction in enteric CH4 emission (221 vs 251 g/day and 8.1 vs 9.0 g/kg of energy-corrected milk), and this response persisted in the extension period. Cows fed RSC had higher milk yield compared with cows fed CC (31.7 vs 29.6 kg/day). However, milk fat and protein content were lower in milk from cows fed RSC than CC. Therefore, energy-corrected milk was not affected by treatment. Feeding RSC lowered milk fat content of palmitic acid compared with CC. The study showed that adding crushed RSC to the diet can be an effective means of reducing CH4 emissions from lactating dairy cows on pasture, without negatively affecting milk production.

Three primiparous dairy cows in early lactation with cannulas in rumen, duodenum and ileum were used in a 3×3 Latin square design to study effects of expander treatment of a barley-based concentrate. The concentrate was either pelleted at 75–80°C or expander treated at 125–130°C prior to pelleting. The diets consisted of 6.7 kg DM of grass silage and 10 kg DM of (1) 100% pelleted, (2) 50% pelleted and 50% expanded or (3) 100% expanded concentrate. The diets were offered as a mixed ration in four equal meals daily. Ruminal fermentation, bacterial N synthesis, duodenal, ileal and faecal flow of nutrients, and animal performance were monitored. Expander treatment numerically increased ruminal digestion of starch, which explained the observed increase in ruminal VFA concentration and the lowered ruminal pH ( P P P

The main purpose of this study was to examine sources of variation in free amino acids (FAA) in the rumen and their relative contribution to the total duodenal amino acid supply. Six cannulated lactating dairy cows fed three concentrate mixtures differing in ruminally degradable intake protein (101, 114 and 134 g kg-1 dry matter) at two levels of intake (19.3 vs 9.8 kg dry matter day-1

Commercial solvent extracted soybean meal (SBM) and fish meal (FM) subjected to additional moist heat for 30 min at 120 or 130°C were investigated in terms of amino acid (AA) composition, total tract digestibility in mink, rumen and total tract digestibility in dairy cows of crude protein (CP) and individual AA. Heat treatment of SBM at 130°C caused significant reduction of the content of Arg, Lys and Cys by 4.1, 8.2 and 12.5%, respectively. Digestibility in mink of CP and most AA was significantly reduced after heat treatment of SBM at 120°C and further at 130°C. The digestibilities of Cys, Asp and Lys, which were the most severely affected AA, declined with 12.3, 10.9 and 8.8 percentage units, respectively, after treatment at 130°C. Heat treatment of FM at 120°C caused reduced digestibility of CP and His, Ile, Lys, Met, Asp, Glu, Gly, and Ser, while heat treatment at 130°C reduced total tract digestibility of CP and all AA in mink. Digestibility of Asp and Cys were most affected after heat treatment at 130°C with reduction of 17.9 and 11.4 percentage units, respectively. Rumen degradability of CP and all AA was significantly lowered by heat treatment of SBM. Met and Glu were the most affected AA, with a reduction of degradability after 16 h rumen incubation of 62.1 and 58.0 percentage units, respectively, after treatment at 130°C. Heat treatment of FM at 120°C caused declined rumen degradability of CP and total AA, although not to the same extent as for SBM. There was no additional effect on rumen degradability of treatment at 130°C of FM. Rumen degradation of Glu and His, the most affected AA, in FM was reduced with 25.1 and 20.3 percentage units, respectively, following heat treatment at 120°C. Ruminant total tract digestibility of CP and AA was not significantly affected by treatment for either of the protein sources. Additional heat treatment of SBM reduced the rumen degradability of protein and AA more than treatment of FM, while for the nonruminant mink, total tract digestibility of SBM and FM was reduced similarly following heat treatment.

Six dairy cows fitted with rumen and duodenal cannulae were assigned to two replicated 3×3 Latin squares in order to examine amino acid (AA) composition of rumen liquid‐associated bacteria (LAB) and solid‐adherent bacteria (SAB). Treatments comprised three concentrate mixtures differing in the amount of rumen degradable intake protein (DIP): 13.4, 11.4 and 10.1% of DM, respectively. Measurements were taken in early lactation, at high feeding level (19.7 kg DM day−1), and repeated at late lactation (10 kg DM day−1) with the same animals and diets. The SAB contained more AA than LAB (P < 0.05), and differences in AA profiles between LAB and SAB were observed for 9 out of 17 AA studied. Feeding level affected only four AA. Increased levels of DIP in the concentrate mixtures increased the content of AA in the bacteria (P < 0.05). Addition of formaldehyde to the ruminai samples prior to bacterial isolation reduced the total AA content by 11%, on average.

To increase food production while minimizing its influence on climate change, farming systems in future will need to reduce greenhouse gas (GHG) emissions per unit of product (i.e., GHG intensity). To assess the level and variation in GHG emissions intensity among Norwegian dairy farms, we conducted an analysis of 30 dairy farms to calculate farm scale emissions of GHGs, expressed as CO2 equivalents (CO2eq) per kg fat and protein corrected milk (FPCM), and CO2eq/kg carcass weight (CW) sold. A model, HolosNor, was developed to estimate net GHG emissions, including soil C changes, from dairy farms. The model requires farm scale input data of soil physical characteristics, weather, and farm operations. Based on data from 2008 the estimated level of GHG intensity was 1.02 kg CO2eq kg−1 FPCM, 21.67 kg CO2eq kg−1 CW sold as culled cows and heifers, and 17.25 kg CO2eq kg−1 CW sold as young bulls. On average, enteric CH4 was the largest emission source both per unit FPCM and CW, accounting for 0.39 kg CO2eq kg−1 FPCM, 8.34 kg CO2eq kg−1 CW sold as culled cows and heifers, and 6.84 kg CO2eq kg−1 CW sold as young bulls. Variation in the estimated soil N2O emissions was the source that contributed the most to the total variation among the farms; the difference between the minimum and the maximum levels was estimated to be 0.30 kg CO2eq kg−1 FPCM, and 6.43 and 6.49 kg CO2eq kg−1 CW sold as culled cows/heifers and young bulls, respectively. Other GHG emission sources also varied considerably among the farms; similar to the N2O emissions, higher emissions of enteric CH4, indirect energy use due to manufacturing of farm inputs, and soil C change all contributed to the higher GHG intensity of some farms. Our study estimates large variation in GHG intensity among dairy farms in Norway and indicates a sensitivity of the emissions to mitigation measures. Production of milk and beef is a complex biological system, thus mitigation options are likely to be most successful when applied in small steps. Thus, the most valuable contribution of the current work is the framework of an on-farm tool for assessing farm-specific mitigation options of Norwegian dairy and beef production.

International audience; The aim of this study was to predict the fatty acid (FA) composition of bulk milk using data describing farming practices collected via on-farm surveys. The FA composition of 1,248 bulk cow milk samples and the related farming practices were collected from 20 experiments led in 10 different European countries at 44 degrees N to 60 degrees N latitude and sea level to 2,000 m altitude. Farming practice-based FA predictions [coefficient of determination (R-2) >0.50] were good for C16:0, C17:0, saturated FA, polyunsaturated FA, and odd-chain FA, and very good (R-2 >= 0.60) for trans-11 C18:1, trans-10 + trans-11 C18:1, cis-9,trans-11 conjugated linoleic acid, total trans FA, C18:3n-3, n-6:n-3 ratio, and branched-chain FA. Fatty acids were predicted by cow diet composition and by the altitude at which milk was produced, whereas animal-related factors (i.e., lactation stage, breed, milk yield, and proportion of primiparous cows in the herd) were not significant in any of the models. Proportion of fresh herbage in the cow diet was the main predictor, with the highest effect in almost all FA models. However, models built solely on conserved forage-derived samples gave good predictions for odd-chain FA, branched-chain FA, trans-10 C18:1 and C18:3n-3 (R-2 >= 0.46, 0.54, 0.52, and 0.70, respectively). These prediction models could offer farmers a valuable tool to help improve the nutritional quality of the milk they produce.

The effect of rumen incubation on the true indigestibility of feed protein in the digestive tract (TIFP) was studied for 10 concentrates. Only fish meal and soybean meal showed a constant TIFP independent of rumen incubation time or extent of rumen protein degradation. For the other feedstuffs, TIFP decreased to various degrees at increased ruminal protein degradation. For extracted rapeseed meal, maize gluten meal and guar meal, however, TIFP measured without pre-incubation in the rumen was also satisfactory as a basis for predicting the true digestibility of rumen undegraded feed protein in the intestine (TDRUP) for practical purposes. In contrast, TIFP for predicting TDRUP for peas, rapeseeds, lupin seeds, barley and oats should be determined on feed samples after rumen incubation.

The objective of this study was to test the efficacy of Propionibacterium strains to mitigate enteric methane (CH4) emissions in beef heifers fed a mixed diet. An experiment was conducted with 16 ruminally cannulated beef heifers fed a basal diet consisting of 60 : 40 barley silage : barley grain (DM basis). Treatments included: (1) Control, (2) Propionibacterium freudenreichii T114, (3) P. thoenii T159, and (4) P. freudenreichii T54. Strains (1 × 1011 colony forming units) were administered daily directly into the rumen before feeding. No treatment effects were observed for DM intake (P = 0.90), mean ruminal pH (P = 0.50) and total volatile fatty acids (P = 0.44). However, compared with the Control, proportions of individual volatile fatty acids changed with acetate being less with Propionibacterium T159 (P = 0.02), whereas ruminal isobutyrate (P < 0.01) and acetate : propionate ratio (P = 0.04) were greater with Propionibacterium T114. Total daily enteric CH4 production averaged 188 g/day and was not affected by Propionbacterium strains (P = 0.51). Methane yield averaged 22 g/kg of DMI intake and tended to be greater with Propionibacterium strains (P = 0.08). The relative abundance of total Propionibacteria was greater with the inoculation of Propionibacterium T159 relative to the Control heifers (P = 0.04). In conclusion, inoculation of Propionibacterium T159 decreased ruminal acetate proportion and Propionibacterium T114 increased acetate : propionate ratio. However, inoculated strains failed to lower total CH4 emissions possibly due to the inability of Propionibacterium strains to elevate ruminal propionate concentrations.

In previous studies, administration of high amounts of Co decreased the proportion of MUFA in bovine milk. The present study was conducted to examine the amount of Co needed to obtain this effect. High-yielding dairy cows (n4), equipped with ruminal cannulas, were used in a 4 × 4 Latin square design study. The basal diet consisted of concentrate mixture (9 kg/d) without added Co and grass silage (ad libitum). The following four levels of Co were administrated as cobalt acetate dissolved in distilled water: no Co (treatment 1, T1); 4·0 mg Co/d (T2); 380 mg Co/d (T3); 5300 mg Co/d (T4). Each period lasted for 18 d, including 11 d of treatment. During the treatment periods, the solutions were continuously infused into the rumen. Milk yield and milk concentration of fat, fatty acids (FA), protein, lactose, Co, Zn, Fe and Cu were determined. Blood plasma was analysed with respect to FA, Co, Zn, Fe and Cu. Feed intake and total tract digestibility of feed components were also determined. There was a linear effect of increasing the level of Co on milk FA composition. The effects of Co on FA composition in blood were insignificant compared with the effects on milk. In milk fat, the concentration ofcis-9-18 : 1 was reduced by as much as 38 % on T4 compared with T1. Feed intake and milk yield were negatively affected by increasing the Co level.

Ruminal biohydrogenation and transfer of fatty acids (FA) to milk were determined for 4 silages with different botanical compositions using 4 multiparous Norwegian Red dairy cows [(mean ± SD) 118 ± 40.9 d in milk, 22.5 ± 2.72 kg of milk/d, 631 ± 3.3 kg of body weight, 3.3 ± 0.40 points on body condition score at the start of the experiment] fitted with rumen cannulas. Treatments consisted of 4 experimental silages: a mix of the first and third cut of organically managed short-term grassland with timothy (Phleum pratense L.) and red clover (Trifolium pratense L.; 2 yr old; ORG-SG); organically managed long-term grassland with a high proportion of unsown species (6 yr old; ORG-LG); conventionally managed ley with perennial ryegrass (Lolium perenne L.; CON-PR); and conventionally managed ley with timothy (CON-TI). The herbages were cut, wilted, and preserved with additive in round bales and fed at 0.90 of ad libitum intake. A barley (Hordeum vulgare L.) concentrate constituted 300 g/kg of dry matter of the total feed offered. A Latin square design (4 × 4) with 3-wk periods and the last week in each period used for sampling was implemented. Omasal flows of FA were measured using Yb acetate, Cr-EDTA, and the indigestible neutral detergent fiber fraction as indigestible markers. The composition of FA was analyzed in feed, omasal digesta, and milk. Compared with ORG-LG, ORG-SG had a higher herbage proportion of red clover (0.36 vs. 0.01) and lower proportions of timothy (0.42 vs. 0.18), smooth meadowgrass (Poa pratensis L.), meadow fescue (Festuca pratensis Huds.), white clover (Trifolium repens L.), dandelion (Taraxacum spp.), and creeping buttercup (Ranunculus repens L.). The silages were well preserved. The concentration of neutral detergent fiber was higher and the concentration of Kjeldahl-N was lower for CON-TI than for the other silages. Silage type had no effect on dry matter intake, but milk yield was lower for CON-TI than for the other silages. Apparent biohydrogenation of C18:3n-3 was lower for ORG-SG (932 g/kg) than for ORG-LG (956 g/kg), CON-PR (959 g/kg), and CON-TI (958 g/kg). Compared with the grass-based silages, ORG-SG and ORG-LG resulted in higher omasal flows of C18:1 trans FA and higher milk fat proportions of C18:1 trans FA and C18:2 cis-9,trans-11. Apparent recovery of C18:3n-3 in milk was higher for ORG-SG (61 g/kg) than for ORG-LG (33 g/kg), CON-PR (34 g/kg), and CON-TI (38 g/kg), and milk fat proportion of C18:3n-3 was higher for ORG-SG than for CON-TI. Milk fat proportions of C16:0 were lower for ORG-SG and ORG-LG compared with those for CON-PR and CON-TI. It was concluded that high proportions of red clover and other dicotyledons in the silages affected ruminal biohydrogenation and increased milk fat proportions of beneficial FA.

To assess greenhouse gas (GHG) emission intensity and its variation in Norwegian pig production, we conducted an analysis of 15 farrow-to-finish pig farms to calculate farm-scale emissions of GHGs,...

Methane production from wheat- or corn-based dried distillers' grains with solubles (CDDGS, WDDGS) was compared in vitro. Wheat DDGS (49 g fat/kg dry matter [DM]) or CDDGS (115 g fat/kg DM) partially or completely replaced whole-crop barley silage at 200, 400, 600, 800 or 1000 g/kg DM. Production of CH4 increased linearly and quadraticly (p

Controlling the time of harvest to affect grass maturity for silage was evaluated as a methane (CH4) mitigation strategy in a batch culture in vitro with ruminal fluid as inoculum and silage from a mixed timothy (Phleum pretense)-meadow fescue (Festuca pratensis) stand. The stand was cut in May (early maturity [EM]; first cutting), June (late maturity [LM]; first cutting), and August (mid-maturity [MM]; third cutting). Disappearance of neutral detergent fiber (NDF) (EM: 0.58; MM: 0.50; LM: 0.45) and ADF (EM: 0.57; MM: 0.49; LM: 0.45) after 48 h was greater for EM compared to MM and LM, with no difference between the latter two. With advancing maturity, total gas (EM: 166.6; MM: 149.7; LM: 119.3 mL), CH4 production (EM: 21.4; MM: 17.6; LM: 14.8 mL), and methane production per g NDF digested decreased at 48 h (EM: 120; MM: 92; LM: 74 mL/g NDF digested). Ensiling less mature grass resulted in more CH4 per unit of NDF digested.

Effects of oils and plant extracts on CH4 production from a barley grain (47%) – barley silage diet [53%; dry matter (DM) basis] were investigated. Exp. 1 used ruminal fluid alone (control), canola...

The aim of the study was to assess impacts of increasing dietary levels of glycerol on in vitro ruminal fermentation and CH4 production from a barley based feedlot diet. Glycerol was used as replacement for barley grain at inclusions of 0, 70, 140 and 210 g/kg of diet dry matter (DM) in a diet containing an equal mixture of barley grain and barley silage. Both grain and silage were dried and ground through a 1 mm screen before mixing with glycerol. The experiment was repeated (n = 2) using ANKOM® bags in 50 ml sealed batch culture serum vials (i.e., 0.5 g substrate + 25 ml media) with a 3:1 ratio of buffer:rumen liquor (n = 5 bags/treatment/experiment). Rumen liquor was obtained from two cows fed a diet containing 710 g/kg barley silage, 250 g/kg barley grain and 40 g/kg concentrate (DM basis). Gas production was measured by water displacement at 3, 6, 12, 24, 36 and 48 h after inoculation. Volumes corrected for gas released from 15 negative controls (i.e., no substrate) were used to estimate net gas production at 24 and 48 h. Gas samples collected at 24 and 48 h were analyzed for CH4 concentration. In vitro DM disappearance (IVDMD) and culture pH were measured at 48 h. Cumulative gas production as ml/g DM substrate and IVDMD were similar among treatments. Culture pH did not differ among treatments. Total CH4 production (as mg or as mg CH4/g digested DM) did not differ among treatments. Results suggest that replacing barley grain with glycerol did not reduce in vitro CH4 production as a function of digested DM or substrate DM. This article is part of the special issue entitled: Greenhouse Gases in Animal Agriculture – Finding a Balance between Food and Emissions, Guest Edited by T.A. McAllister, Section Guest Editors; K.A. Beauchemin, X. Hao, S. McGinn and Editor for Animal Feed Science and Technology, P.H. Robinson.

The effect of cows' diets on milk composition is discussed, focusing on those components of particular interest for human health. First dietary sources of fatty acids and their digestion and metabolism are reviewed. Then feeding factors affecting milk fat content and fatty acid composition are discussed, with emphasis on those factors related to forage and fat supplements. The effects of diet on protein content and composition and milk content of minerals and vitamins are reviewed. Feeding strategies for improving the nutritional quality of milk are summarized.

Milk has been an important part of Norwegian nutrition for generations. The article is a review of literature concerning research on milk and health.Relevant literature with results that were confirmed by others were chosen from acknowledged journals from Pubmed in the period 1977-2006, by using the search words milk, fat, atherosclerosis, omega-3, omega-6, cancer, allergy, trace elements, iodine and selenium.Milk and milk products contain many essential nutrients. The content of oleic acid, conjugated linoleic acid, omega-3 fatty acids, short- and medium chain fatty acids, vitamins, minerals and bioactive compounds may promote positive health effects. Certain studies indicate that a moderate intake of milk fat reduces the risk of cardiovascular disease, possibly through reduced formation of small dense LDL-particles, despite of its inherent tendency to increase total cholesterol. For individuals with genetic metabolic defects, milk proteins, fat and milk sugar may cause health problems. The low pH in fermented milk and the formation of substances during the fermentation process may have a beneficial effect. Full-fat milk and fermented milk lead to delayed gastric emptying, and thereby to reduced glycaemia and reduced appetite. Harmful substances may be formed when proteins react with sugar, especially at a high temperature; a fact that should be considered with an increasing use of sweetened milk products. The cow's diet affects the milk's content of many nutrients as for example fatty acids, iodine and selenium. The composition of milk for commercial use should be investigated.