Yeast in forage crops and silage aerobic stability at 15 Swedish dairy farms
This study investigates the role of yeast in green crop and its impact on the aerobic stability of silage. Fresh crop was collected from 15 farms in southern and middle parts of Sweden during the summer 2014; samples from the primary harvest was collected from eight farms and samples from the first...
| Autor principal: | |
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| Formato: | H2 |
| Lenguaje: | Inglés sueco |
| Publicado: |
SLU/Dept. of Animal Nutrition and Management (until 231231)
2015
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| Materias: |
| _version_ | 1855571242175692800 |
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| author | Persson, Annica |
| author_browse | Persson, Annica |
| author_facet | Persson, Annica |
| author_sort | Persson, Annica |
| collection | Epsilon Archive for Student Projects |
| description | This study investigates the role of yeast in green crop and its impact on the aerobic stability of silage. Fresh crop was collected from 15 farms in southern and middle parts of Sweden during the summer 2014; samples from the primary harvest was collected from eight farms and samples from the first regrowth harvest was collected from seven farms. The grass was ensiled in 1.7 l glass silos. After three months of ensiling, silos were opened and silages were stored aerobically for 10 days. Samples from both harvests were ensiled in completely airtight silos, but samples from the second harvest were also ensiled in slightly ventilated silos.
Chemical analyses and yeast counts were performed for fresh crop and silage. During the ensiling period, weight loss was registered for all silos and during the aerobic stability test, the temperature in the silage was measured every second hour throughout a ten day period. Yeast
species present in the fresh crop were identified with DNA sequencing. Data of management applied in silage making was collected from the 15 farms and processed in relation to silage quality.
Dry matter (DM) content of the fresh crops ranged from 22.2 to 52.8 %, metabolizable energy content from 9.2 to 11.6 MJ/kg DM, crude protein (CP) content from 110 to 190 g/kg DM and water soluble carbohydrate content (WSC) ranged from 38 to 118 g/kg DM. Yeast counts in the fresh crop averaged log 5.4 colony forming units/g (min log 4.6; max log 5.9) with no difference between first and second harvest. No correlation was found between fresh crop and silage yeast counts. Among the yeast isolates, 16 different yeast species were identified with Rhodosporidium babjeave and Rhodotorula glutenis being the two most common. In the air
tight silos, yeast count was higher in the first harvest than in the second harvest. Among management factors a tendency was observed for higher yeast counts in the fresh crop when manure was used instead of inorganic fertilizer. Silage from the second harvest had shorter aerobic storage stability compared to silage from the first harvest. Also silages with high DM content had shorter aerobic stability than silages with low DM content.
Comparing the air-tight and slightly ventilated silos, the number of yeasts were higher in ventilated than in air- tight silos after the ensiling period. Weight loss was 3.1% of the initial DM in air-tight silos and 3.4% in ventilated silos during the ensiling period. Content of WSC
decreased during ensiling by 81% of the initial WSC content in both air-tight and ventilated silos (s.d. 12.59% air-tight; s.d. 13.97% ventilated). After aerobic storage the weight loss was 15.3% of the initial DM (s.d. 8.86%) in the air-tight silos and 28.9% of the initial DM (s.d. 14.99%) in the ventilated silos. Loss of WSC content after the aerobic stability test was 32.6% (s.d. 33.11%) in air-tight silos compared to WSC content at the opening of the silo and 51.6% (s.d. 36.44%) in ventilated silos.
The results showed that the greatest weight loss occurred during the first week of ensiling.
The decrease in WSC content, yeast counts and weight loss were lower in air-tight silos compared to ventilated silos and silage in air-tight silos also had longer aerobic stability than silage in ventilated silos. Higher DM content also resulted in shorter aerobic stability. High
numbers of yeast in the silage at silo opening was highly correlated to shorter aerobic stability. |
| format | H2 |
| id | RepoSLU7780 |
| institution | Swedish University of Agricultural Sciences |
| language | Inglés swe |
| publishDate | 2015 |
| publishDateSort | 2015 |
| publisher | SLU/Dept. of Animal Nutrition and Management (until 231231) |
| publisherStr | SLU/Dept. of Animal Nutrition and Management (until 231231) |
| record_format | eprints |
| spelling | RepoSLU77802015-04-21T13:40:03Z Yeast in forage crops and silage aerobic stability at 15 Swedish dairy farms Jäst i grönmassan och ensilagets lagringsstabilitet vid 15 svenska mjölkgårdar Persson, Annica fungi grass crop ensiling hygienic quality losses jäst ensilage lagringsstabilitet grönmassa This study investigates the role of yeast in green crop and its impact on the aerobic stability of silage. Fresh crop was collected from 15 farms in southern and middle parts of Sweden during the summer 2014; samples from the primary harvest was collected from eight farms and samples from the first regrowth harvest was collected from seven farms. The grass was ensiled in 1.7 l glass silos. After three months of ensiling, silos were opened and silages were stored aerobically for 10 days. Samples from both harvests were ensiled in completely airtight silos, but samples from the second harvest were also ensiled in slightly ventilated silos. Chemical analyses and yeast counts were performed for fresh crop and silage. During the ensiling period, weight loss was registered for all silos and during the aerobic stability test, the temperature in the silage was measured every second hour throughout a ten day period. Yeast species present in the fresh crop were identified with DNA sequencing. Data of management applied in silage making was collected from the 15 farms and processed in relation to silage quality. Dry matter (DM) content of the fresh crops ranged from 22.2 to 52.8 %, metabolizable energy content from 9.2 to 11.6 MJ/kg DM, crude protein (CP) content from 110 to 190 g/kg DM and water soluble carbohydrate content (WSC) ranged from 38 to 118 g/kg DM. Yeast counts in the fresh crop averaged log 5.4 colony forming units/g (min log 4.6; max log 5.9) with no difference between first and second harvest. No correlation was found between fresh crop and silage yeast counts. Among the yeast isolates, 16 different yeast species were identified with Rhodosporidium babjeave and Rhodotorula glutenis being the two most common. In the air tight silos, yeast count was higher in the first harvest than in the second harvest. Among management factors a tendency was observed for higher yeast counts in the fresh crop when manure was used instead of inorganic fertilizer. Silage from the second harvest had shorter aerobic storage stability compared to silage from the first harvest. Also silages with high DM content had shorter aerobic stability than silages with low DM content. Comparing the air-tight and slightly ventilated silos, the number of yeasts were higher in ventilated than in air- tight silos after the ensiling period. Weight loss was 3.1% of the initial DM in air-tight silos and 3.4% in ventilated silos during the ensiling period. Content of WSC decreased during ensiling by 81% of the initial WSC content in both air-tight and ventilated silos (s.d. 12.59% air-tight; s.d. 13.97% ventilated). After aerobic storage the weight loss was 15.3% of the initial DM (s.d. 8.86%) in the air-tight silos and 28.9% of the initial DM (s.d. 14.99%) in the ventilated silos. Loss of WSC content after the aerobic stability test was 32.6% (s.d. 33.11%) in air-tight silos compared to WSC content at the opening of the silo and 51.6% (s.d. 36.44%) in ventilated silos. The results showed that the greatest weight loss occurred during the first week of ensiling. The decrease in WSC content, yeast counts and weight loss were lower in air-tight silos compared to ventilated silos and silage in air-tight silos also had longer aerobic stability than silage in ventilated silos. Higher DM content also resulted in shorter aerobic stability. High numbers of yeast in the silage at silo opening was highly correlated to shorter aerobic stability. I den här studien undersöktes jästs roll i grönmassa och dess inverkan på den aeroba stabiliteten i ensilage. Grönmassa samlades från 15 gårdar i södra och mellersta delarna av Sverige under sommaren 2014 och ensilerades i 1,7 liters silor. Åtta av proverna var från första skörden och sju var från andra skörden. Efter en ensileringsperiod på tre månader lagrades ensilaget aerobt i 10 dagar. Proverna från de båda skördarna ensilerades helt anaerobt, men prover från andra skörden ensilerades även i silor som ventilerades med jämna mellanrum. Analys av kemisk sammansättning och jästantal gjordes på grönmassan och ensilaget. Under ensileringen registrerades viktförlusten. Temperaturen registrerades varannan timme under den aeroba lagringen. Jästarterna från grönmassan identifierades genom DNAsekvensering. Information om ensilageskörden samlades in från varje gård. Torrsubstanshalten (ts) i grönmassan varierade från 22.2% till 52.8%, mängden omsättbar energi från 9,2 till 11,6 MJ/kg ts, råproteinhalten från 110 till 190 g/kg ts och sockerinnehållet (lättlösliga kolhydrater, WSC) varierade från 38 till 118 g/kg ts. Antalet jäst i grönmassan var i medel log 5,4 (min 4,6; max 5,9) och det var ingen skillnad mellan första och andra skörden. I grönmassan identifierades 16 olika jästarter och Rhodosporidium babjeave och Rhodotorula glutenis var de arter som var mest vanliga. Jästantalet i ensilaget från lufttäta silor var högre i andra jämfört med förstaskörden. Ingen korrelation fanns mellan jästantalet i grönmassan och i ensilaget. Bland de variabler som rörde handhavandet av ensileringen fanns det en tendens till ökat jästantal ökade i grönmassan när stallgödsel användes jämfört med konstgödsel. Ensilaget från andraskörden hade kortare aerob lagringsstabilitet än ensilaget från förstaskörden. Även ensilage med högre ts-halter hade kortare lagringsstabilitet. Vid jämförelse av lufttäta och ventilerade silor hade ensilaget från de ventilerade silorna högre antal jäst efter ensileringen. Under ensileringsperioden var viktminskningen 3,1 % av ursprunglig ts i de lufttäta silorna och 3,4 % i de ventilerade silorna. Minskningen i halten lättlösliga kolhydrater under ensileringen var 81 % i både lufttäta och ventilerade silor (sd 12.59 % i lufttät silo; sd 13.97 % i ventilerad silo). Under den efterföljande aeroba lagringen var viktminskningen 15,3% av ursprunglig ts (sd 8,86 %) i de lufttäta silorna och 28,9% (sd 14,99 %) i de ventilerade silorna. Minskningen av WSC-halten efter det aeroba stabilitetstestet var 32.6 % (sd 33.11 %) jämfört med värdet vid öppning av silorna i de lufttäta och 51.6% (sd 36.44%) i de ventilerade silorna. Resultaten visade att den största viktminskningen skedde under den första veckan av ensileringen. I de lufttäta silorna var minskningen av halten lättlösliga kolhydrater och jästantalet samt viktminskningen under ensileringen lägre än i de ventilerade silorna. Ensilaget i de lufttäta silorna hade också en längre aerob lagringsstabilitet än ensilaget från de ventilerade silorna. Höga ts-halter gav också kortare aerob lagringsstabilitet. Högt antal jäst i ensilaget vid siloöppningen var starkt korrelerat med kortare aerob lagringsstabilitet. SLU/Dept. of Animal Nutrition and Management (until 231231) 2015 H2 eng swe https://stud.epsilon.slu.se/7780/ |
| spellingShingle | fungi grass crop ensiling hygienic quality losses jäst ensilage lagringsstabilitet grönmassa Persson, Annica Yeast in forage crops and silage aerobic stability at 15 Swedish dairy farms |
| title | Yeast in forage crops and silage aerobic stability at 15 Swedish dairy farms |
| title_full | Yeast in forage crops and silage aerobic stability at 15 Swedish dairy farms |
| title_fullStr | Yeast in forage crops and silage aerobic stability at 15 Swedish dairy farms |
| title_full_unstemmed | Yeast in forage crops and silage aerobic stability at 15 Swedish dairy farms |
| title_short | Yeast in forage crops and silage aerobic stability at 15 Swedish dairy farms |
| title_sort | yeast in forage crops and silage aerobic stability at 15 swedish dairy farms |
| topic | fungi grass crop ensiling hygienic quality losses jäst ensilage lagringsstabilitet grönmassa |