| 1. |
- Arvidsson Segerkvist, Katarina, et al.
(författare)
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Effects of conservation method on fatty acid composition of silage
- 2009
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Ingår i: Animal Feed Science and Technology. - : Elsevier BV. - 0377-8401 .- 1873-2216. ; 148, s. 241-252
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Tidskriftsartikel (refereegranskat)abstract
- This experiment was conducted to investigate effects of willing and additives on the fatty acid (FA) composition of grass silage. The crop used was timothy (Phelum pratense L., cv. Grindstad), and the additives were Proens (TM) (formic acid and propionic acid, 60-66 g/100 g and 25-30 g/100 g, respectively), the bacterial inoculant Silofenn (R) Plus (Pediococcus acidilactici and Lactobacillus plantarum) and water (control). The wilted material reached a dry matter (DM) content of 336 g/kg at the first cut and 350 g/kg at the second cut. Neither wilting nor the additives had any major effect on the FA proportions, with the only differences in the concentrations of C16:0 and C 18:3. Silage treated with bacterial inoculant contained a higher proportion of C16:0 (P<0.05) than silage treated with acid, and a lower (P<0.05) concentration of C 18:3 than silage treated with either of the other two additives. In the silages, there were lower (P<0.05) proportions of C:16:0, C 18:0, C 18:1 and C 18:3, and higher (.P<0.05) proportions of C 16: 1, C 19:2 and other identified FAs, than in the fresh material. A wilting process shorter than 24 h. to it DM content of 330-350 g/kg, did not have my effect on the proportions of FAs in P. pratense L., cv. Grindstad. Since the different additives and wilting strategies tested in this study did not affect the proportions of FAs in silage to a major extent, the results indicate that such it process offers a robust means to avoid losses of FAs that can occur during wilting, while retaining the positive effects of wilting, such its reduced losses of nutrients through effluents. (C) 2008 Elsevier B.V. All rights reserved.
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| 2. |
- Arvidsson Segerkvist, Katarina, et al.
(författare)
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Fatty acid concentrations in timothy (Phleum pratense L.) and meadow fescue (Festuca pratensis Huds.): Effects of seasonal variations at different nitrogen fertilization levels
- 2013
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Ingår i: Acta Agriculturae Scandinavica, Section B - Soil and Plant Science. - : Informa UK Limited. - 0906-4710 .- 1651-1913. ; 63, s. 314-321
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Tidskriftsartikel (refereegranskat)abstract
- Timothy (Phleum pratense L.) and meadow fescue (Festuca pratensis Huds.) were subjected to three different nitrogen (N) fertilization regimes (30+30, 90+90, and 120+90 kg N ha(1); N-30, N-90, and N-120 treatments, respectively) and harvested at three different stages of maturity during spring growth and at two different maturity stages during summer growth. In addition, N-90 plots were sampled on one additional occasion during spring growth and two additional occasions during summer growth. Total fatty acid concentrations and concentrations of the four major fatty acids (C16:0, C18:1n-9, C18:2n-6, and C18:3n-3), which account for 9094 g 100 g(1) of the total fatty acid contents of both grasses, declined over time during both growth periods in both grass species (p < 0.001), irrespective of N-fertilization level. Moreover, the relative proportions of the four fatty acids were affected by the harvest date (p < 0.001); C16:0, C18:1n-9, and C18:2n-6 increased in abundance at later harvest dates, while the opposite was true for C18:3n-3. There were differences (p < 0.05) between timothy and meadow fescue in terms of the concentrations of C16:0, C18:1n-9, C18:2n-6, and C18:3n-3, and in the relative proportions (p < 0.001) of C16:0, C18:2n-6, and C18:3n-3. Meadow fescue contained higher concentrations of C16:0, C18:1n-9, and C18:3n-3, while timothy contained higher concentrations of C18:2n-6. However, the total fatty acid concentrations for both species were similar. The N-fertilization level did not directly affect (p > 0.05) the concentrations or relative proportions of the different fatty acids, but positive linear relationships (p < 0.001) were identified between the concentrations of fatty acids and crude protein. Consequently, there is a scope for adjusting the fatty acid profile and content of forage by changing the grass species used and the time of harvest, with the latter having the greatest influence.
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| 3. |
- Arvidsson Segerkvist, Katarina, et al.
(författare)
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Fatty acids in forages: A comparison of different pre-treatments prior to analysis
- 2009
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Ingår i: Animal Feed Science and Technology. - : Elsevier BV. - 0377-8401 .- 1873-2216. ; 151, s. 143-152
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study was to compare the merits of various possible pre-treatments of samples of grass prior to fatty acid (FA) analysis. Initially, samples of both first and second cuts of a timothy ley (Phleum pratense L., cv. Grindstad) were subjected to ten different pre-treatments, including freezing with liquid N, freezing at -20°C and drying in an air-forced oven, then storage for eight to nine months. Their fatty acid contents were then determined, as fatty acid methyl esters, by gas chromatography. There were no distinct between-treatment differences in the determinations of total FA concentrations for either cut. However, there were treatment differences in the measured proportions of C16:0 and C18:0 (P < 0.01) for both cuts. There were also a few small differences (P < 0.05) in the proportions of C18:3 found in samples from both cuts, but not in their proportions of either C18:1 or C18:2. In subsequent experiments, samples from the first cut frozen at -20°C or dried in an air-forced oven were subjected to further treatments to investigate the effects of grinding and freeze-drying.. Samples of a second cut of red clover (Trifolium pratense L., cv. Betty) were also included in these experiments. There were no major between-preparation differences in the acquired data on FA composition for either the grass or clover samples. Notably, grinding had no significant effects on either the FA proportions or crude fat concentrations in the grass samples, although slightly higher (P < 0.01) proportions of C18:2 were found in the clover samples, and freeze-drying affected the FA proportions to some extent. In grass, freeze-drying resulted in lower (P < 0.05) concentrations of C18:0 and C18:1 compared to freezing alone (-20°C). If samples have to be stored for prolonged periods (such as the eight to nine months in this study) before analysis, drying seems to be a better treatment than freezing at -20°C. Freezing with liquid N was not essential, at least for the examined forages, to obtain apparently reliable information on their FA profiles. Thus, the widely used method of preparing samples prior to analysis, i.e. freeze drying and grinding, appears to be satisfactory, but drying samples seems to be as good or even better in some cases for analysing FA proportions.
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| 4. |
- Arvidsson Segerkvist, Katarina, et al.
(författare)
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Ger kvävegödsling eller inblandning av rödklöver i vallen någon effekt på mjölkens fettsyrasammansättning?
- 2014
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Ingår i: Report from the Department of Crop Production Ecology (VPE). - 1653-5375. ; , s. 117-119
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Ett positivt samband mellan koncentrationen av råprotein och fettsyror har påvisats i en rad olika arter. Syftet med denna studie var att undersöka om detta samband kunde användas för att påverka mjölkens fettsyrasammansättning. Följaktligen gödslades en timotejvall med tre olika nivåer av kväve: 30, 90 och 120 kg N/ha till förstaskörd för att åstadkomma tre ensilage med olika råproteinkoncentration. Ett fjärde ensilage bestående av rödklöver och timotej (60 respektive 40 % på ts-basis) inkluderades också. Studien genomfördes under typiska produktionsbetingelser, dvs. med samma typer och mängder av kraftfoder som på en kommersiell gård. De uppnådda skillnaderna i fettsyrakoncentrationer mellan ensilagen påverkade dock inte mjölken, vilket visar att ökad kvävegödsling, eller inbladning av rödklöver, inte nödvändigtvis leder till högre koncentrationer av fleromättade fettsyror i mjölk vid en foderstat bestående av 60% vallfoder och 40% kraftfoder.
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| 5. |
- Arvidsson Segerkvist, Katarina, et al.
(författare)
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The effect of N-fertilisation rate or inclusion of red clover to timothy leys on fatty acid composition in milk of dairy cows fed a commercial silage: concentrate ratio
- 2012
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Ingår i: Animal. - 1751-7311 .- 1751-732X. ; 6, s. 1178-1186
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this experiment was to, under typical Swedish production conditions, evaluate the effects of grass silages subjected to different N-fertilisation regimes fed to dairy cows on the fatty acid (FA) composition of their milk, and to compare the grass silages in this respect to red clover-dominated silage. Grass silages made from first year Phleum pratense L. leys subjected to three N-fertilisation regimes (30, 90 and 120 kg N/ha, designated G-30, G-90 and G-120, respectively) and a mixed red clover grass silage (Trifolium pratense L. and P. pratense L; 60/40 on dry matter (DM) basis, designated RC G) were produced. The experiment was conducted as a change-over design, including 24 primiparous and multiparous dairy cows of the Swedish Red breed, each of which was allocated to three of the four diets. The cows were offered 11 kg DM of silage and 7 kg concentrates. The silages had similar DM and energy concentrations. The CP concentration increased with increase in N-fertilisation level. There was a linear increase in DM intake of the different silages with increased N fertilisation. There were also differences in concentrations of both individual and total FAs amongst silages. The daily milk production (kg/day) did not significantly differ between treatments, but G-30 silage resulted in higher concentrations of 18:2n-6 in the milk compared with the other two grass silages. The highest concentrations of 18:3n-3 and cis-9, trans-11 18:2 were found in milk from cows offered the RC G silage. The G-30 diet resulted in higher concentration of 18:2n-6 and the same concentration of 18:3n-3 in the milk as the other grass silages, despite lower intake levels of these FAs. The apparent recoveries of 18:3n-3 from feed to milk were 5.74%, 4.27%, 4.10% and 5.31% for G-30, G-90, G-120 and RC G, respectively. A higher recovery when red clover is included in the diet confirms previous reports. The higher apparent recovery of 18:3n-3 on the G-30 treatment may be related to the lower silage DM intake, which led to a higher relative proportion of ingested FAs originating from concentrates compared with the G-90 and G-120 diets. With the rates and types of concentrates used in this study, the achieved differences in FA composition among the silages were not enough to influence the concentrations of unsaturated FAs in milk.
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| 6. |
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| 7. |
- Bernes, Gun, et al.
(författare)
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Baljväxtensilage till får
- 2010
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Ingår i: Nytt från Institutionen för norrländsk jordbruksvetenskap. Ekologisk odling. - 1401-7741.
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Annan publikation (populärvet., debatt m.m.)
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| 8. |
- Bernes, Gun, et al.
(författare)
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Baljväxtensilage till får
- 2011
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Ingår i: Fårskötsel. - 1650-2426. ; , s. 20-23
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 9. |
- Bernes, Gun, et al.
(författare)
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Betesblandning för får - undvik rörsvingel
- 2014
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Ingår i: Nytt / Sveriges lantbruksuniversitet, Institutionen för norrländsk jordbruksvetenskap.
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Annan publikation (populärvet., debatt m.m.)
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| 10. |
- Bernes, Gun, et al.
(författare)
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Jämförelse av vallfröblandningar för fårbete
- 2014
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Ingår i: Report from the Department of Crop Production Ecology (VPE). - 1653-5375. ; , s. 63-66
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Fyra fröblandningar för fårbete har jämförts. Den som innehöll örter gav vissa positiva resultat både i näringsvärde och i djurdata. Dock är det svårt att säkert koppla det till innehållet av örter, då deras andel i beståndet var låg. Den blandning som gav mest negativt avvikande resultat var rörsvingelblandningen. Rörsvingel tycks inte vara särskilt lämpat för fårbete; växten verkar snabbt mista sin smaklighet även om den inte går i ax. Det krävs att man under hela säsongen har tillräckligt med djur så att betestrycket håller ner grödan. Generellt var lammens tillväxt god även när betet växte högt i början av sommaren. Gräset var trots sin längd då fortfarande i vegetativt stadium. Det tyder på att det inte i första hand är beståndshöjden som är avgörande för konsumtion och tillväxt utan smältbarheten. Det ekonomiska resultatet beror på om man utgår från växt- eller djursidan. Växtmässigt gav baljväxtledet högst netto per hektar, och ängssvingelledet lägst. Om man istället utgår från djurens tillväxt var det mest lönsamt med örtblandningen medan rörsvingelblandningen gav sämst resultat.
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