The main objective of this study was to elucidate the potential for prediction of enteric methane (CH ₄) 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 CH ₄ emissions. Models were compared based on mean squared prediction error and concordance correlation coefficient (CCC) analysis. Fermented nutrients did not predict enteric CH ₄ emissions adequately (CCC < 0.420). Including total digested (td) nutrients in the model CH ₄ (MJ/d) = −2.13 + 1.64 tdOM (kg/d) −9.74 tdFat (kg/d) + 1.64 tdNDF (kg/d) predicted enteric CH ₄ emissions more precisely (CCC = 0.733), and showed an improvement in the prediction of enteric CH ₄ 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 (CH^ sub ...4^) emissions, diet digestibility, and N excretion were studied, using 8 ruminally cannulated beef heifers in 2 sequential shortterm 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 1x 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 CH^ sub 4^ 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 CH^ sub 4^ (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 CH^ sub 4^ emissions (22.4 g/kg DMI ± 1.29 SD and 7.1% GEI ± 0.40 SD). However, on the basis of OM digested, CH^ sub 4^ 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 CH^ sub 4^ 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 CH^ sub 4^ emissions from beef cattle fed at maintenance. PUBLICATION ABSTRACT
Two experiments were conducted to evaluate the effects of increasing concentrations of glycerol in concentrate diets on total tract digestibility, methane (CH^sub 4^) 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 CH^sub 4^ emissions from 12 ram lambs were measured in a replicated 4 x 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 CH^sub 4^ 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 CH^sub 4^ 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. PUBLICATION ABSTRACT
The study comprised two samples of solvent-extracted soybean meal (SBM) and two samples of xylose-treated SBM (SoyPass
®). The main objectives were to determine effective rumen degradability (ERD) ...and intestinal indigestibility of their individual amino acids (AA) in situ. The relative contribution of Lys was on average 17% lower and of Arg 7% lower in SoyPass
® than in SBM (
p
<
0.05). Manufacturing of SoyPass
® increased significantly the relative contribution of Ile, Leu, Val and Gly, but these effects were small in magnitude. Effective rumen degradabilities of total AA (TAA) calculated at a rumen outflow rate of 8%
h
−1, was as low as 29% for SoyPass
® compared to 53% for SBM. The corresponding values for crude protein (CP) were 27 and 52% for SoyPass
® and SBM, respectively. In SBM, Arg, Glu and Lys had higher (
p
<
0.05) ERD than TAA, whereas Ser, Phe, Leu, Gly, Thr, Tyr, Ile, Cys, Val, Ala and Met showed lower (
p
<
0.05) ERD than TAA. In SoyPass
®, ERD of Lys and Cys did not differ significantly from TAA. With these exceptions, variation in ERD among AA in SoyPass
® was as in SBM. However, the differences between individual AA and TAA were much smaller than in SBM. Intestinal indigestibility of TAA measured on original feed (OF) was 1.8 and 2.0% for SBM and SoyPass
®, respectively (
p
>
0.05). For CP, the corresponding values were 2.0% for SBM and 2.3% for SoyPass
®. Pre-incubating the samples in the rumen for 16
h, numerically decreased intestinal indigestibilities of all individual AA, but the effect was significant for only 5 AA. There were significant differences in intestinal indigestibilities among AA, but the differences were small in magnitude. From the results obtained, it was concluded that, for SBM and SoyPass
®, TAA in the protein fraction digested in the intestine (PDI) can be predicted accurately by using proportion AA-N: N in rumen undegraded protein (RUP) of 0.85, and ERD and intestinal indigestibility as for CP. For SoyPass
®, this way of prediction of individual AA would result in only small errors, at least for those AA which are regarded as limiting in milk production. In contrast, for SBM satisfactory prediction of individual AA absorbed in the intestine requires determination of ERD on individual basis.
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.
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 oil ...(CO), sunflower oil (SO), cod liver oil (CLO), or a (70:30) mixture of CO and CLO (MIX) at 2.5 or 5% of DM. CH₄/g DMD increased (p < 0.05) for CO₅, SO₂.₅, CLO₅, and MIX₅. In Exp. 2, MIX₅, hop extract at 7.5 (H₇.₅) and 15.0 (H₁₅.₀) and steroidal saponin extract at 2.4 (S₂.₄) and 4.8 (S₄.₈)% DM with and without MIX₅ were examined. H₇.₅–MIX and S₂.₄–MIX increased CH₄/g DMD (p < 0.05). Addition of oil resulted in a decline in DMD in both experiments. None of the additives reduced CH₄/g DMD. Further studies to determine if more than one mitigation additive has detrimental or synergistic impacts on CH₄ produced per unit DMD are required.
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, ...expressed as carbon dioxide equivalents (CO₂eq) per kg carcass weight (CW) sold. A model, HolosNor, was developed to estimate net GHG emissions, including soil C changes, from pig farms. Based on data from 2008 the estimated GHG intensity was 2.65 kg CO₂eq kg⁻¹ CW (range: 1.24–4.03). The production of the feed consumed by the pigs contributed most to total GHG emissions; accounting for 2.14 kg CO₂eq kg⁻¹ CW, or more than 80% of the total emissions. Our study estimated a large variation in GHG intensity among pig farms in Norway which indicates opportunity for incorporating mitigation practices. A valuable contribution of the current work is the framework of a farm-scale tool for assessing farm-specific mitigation options.
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.
Hünerberg, M., McGinn, S. M., Beauchemin, K. A., Okine, E. K., Harstad, O. M. and McAllister, T. A. 2013. Effect of dried distillers’ grains with solubles on enteric methane emissions and nitrogen ...excretion from finishing beef cattle. Can. J. Anim. Sci. 93: 373–385. The objective of this study was to examine the impact of corn- or wheat-based dried distillers’ grains with solubles (CDDGS, WDDGS) on enteric methane (CH
4
) emissions from finishing beef cattle, and to determine if any observed reductions were a result of the fat content of CDDGS. A second objective was to compare the effect of CDDGS or WDDGS on N excretion. The experiment was designed as replicated 4×4 Latin square with 28-d periods using 16 ruminally fistulated crossbred heifers. The control diet contained 87% barley grain, 8% barley silage and 5% supplement (dry matter; DM basis). Treatment diets were formulated by replacing 40% DM of barley grain with CDDGS, WDDGS, or corn oil supplemented WDDGS (WDDGS+oil). For the WDDGS+oil diet 6.5% corn oil was added to WDDGS (3.4% fat DM) to achieve a similar fat level as in CDDGS (9.7% DM). All diets were fed as total mixed rations once daily ad libitum. Total collection of urine and faeces was conducted between days 18 and 21. Methane was measured between days 25 and 28 using four identical open circuit respiratory chambers. Compared with WDDGS, feeding CDDGS and WDDGS+oil reduced (P<0.05) CH
4
emissions as a percentage of gross energy intake (GEI) from 5.5 to 4.0 and 4.2%, respectively. Feeding CDDGS also reduced (P<0.05) CH
4
emissions compared with the control (5.0% of GEI), while WDDGS+oil tended (P=0.08) to elicit a similar response. Methane (% of GEI) between WDDGS and the control did not differ (P=0.29). Excretion of total N was greater (P<0.001) for CDDGS, WDDGS and WDDGS+oil (220, 253, and 265 g d
−1
) compared with the control (143 g d
−1
). Although oil appears to be responsible for reducing CH
4
emissions when DDGS is included in the diet, increased N excretion requires that a complete life cycle assessment be conducted to assess the full impact of DDGS on greenhouse gas emissions from finishing cattle.
Corn gluten meal (CGM), canola meal (CM), and two types of fish meal (FM) were examined in situ for rumen degradability (RD) and true intestinal indigestibility (TU) of crude protein (CP) and ...individual amino acids (AA). Results indicate that RD of CP can be used to predict RD of total AA (TAA) for CGM and CM, and probably FM. Differences in RD among AA were observed within all feedstuffs studied. The extent of the differences was larger with the highly rumen degradable CM than with the more resistant CGM and FM. In general, RD of individual AA was feed dependent. The exception was Tyr that had a significantly lower RD than TAA for all three feedstuffs. The TU of CP was a good predictor of intestinal AA indigestibility. In general, the variation in TU among AA was small within feeds. The exception was FM with a high ash fraction, where Gly and Pro had substantial higher TU than the other AA.
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