Ruminal inocula with distinct fermentation profiles differentially affect the in vitro fermentation pattern of a commercial algal blend

The in vitro rumen batch technique is widely used for screening novel feed sources; however, it remains unclear to what extent the in vitro fermentability of non-conventional feed sources is affected by non-adapted ruminal inocula. Thus, in this study, we evaluated the effects of distinct ruminal in...

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Main Authors: Cátia S. C. Mota, Margarida R. G. Maia, Inês M. Valente, Ana R. J. Cabrita, António J. M. Fonseca
Format: Article
Language:English
Published: Frontiers Media S.A. 2024-03-01
Series:Frontiers in Veterinary Science
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/fvets.2024.1346683/full
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author Cátia S. C. Mota
Margarida R. G. Maia
Inês M. Valente
Inês M. Valente
Ana R. J. Cabrita
António J. M. Fonseca
author_facet Cátia S. C. Mota
Margarida R. G. Maia
Inês M. Valente
Inês M. Valente
Ana R. J. Cabrita
António J. M. Fonseca
author_sort Cátia S. C. Mota
collection DOAJ
description The in vitro rumen batch technique is widely used for screening novel feed sources; however, it remains unclear to what extent the in vitro fermentability of non-conventional feed sources is affected by non-adapted ruminal inocula. Thus, in this study, we evaluated the effects of distinct ruminal inocula on the in vitro fermentation parameters of a sustainable non-conventional feed, a commercially available algal blend composed of microalgae (Chlorella vulgaris and Nannochloropsis oceanica) and seaweeds (Ulva sp. and Gracilaria gracilis). First, four late-lactation Holstein cows were fed four forage-based diets varying only in the proportions of basal forage (100% corn silage, 70% corn silage and 30% haylage, 30% corn silage and 70% haylage, and 100% haylage) in a 4 × 4 Latin square design with the last square omitted. After 3 weeks of adaptation, haylage-based diets resulted in ruminal fermentation parameters distinct from those promoted by corn silage-based diets, as reflected in increased pH, ammonia-N contents, and acetate proportions. Individual ruminal fluids derived from each of the four diets were further used as inocula in in vitro incubations. Here, a 1:1 mixture of corn silage and haylage was supplemented with 0, 5, 10, or 15% algal blend and incubated with each inoculum for 24 h in a 4 × 4 factorial design. Total gas and methane production decreased with inocula from cows fed haylage-based diets and with increasing algal blend supplementation levels. The fermentation pH increased and the ammonia-N contents decreased with inocula from cows fed haylage-based diets; however, these parameters were not affected by algal blend inclusion levels. The interaction between the ruminal inoculum source and the algal blend supplementation level affected the total volatile fatty acids (VFA) and the proportions of most individual VFA. Total VFA production decreased with increasing algal supplementation levels, particularly with inocula from cows fed 30% corn silage and 70% haylage; the acetate, propionate, and valerate proportions were only affected by algal blend levels under incubation with 100% corn silage inocula. Overall, our findings highlight the importance of the ruminal inoculum source when assessing the fermentability of non-conventional feed as well as the potential of the algal blend as a natural modulator of ruminal fermentation.
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spelling doaj.art-fc150f3a085b4c76b811a22aaf9a4b3b2024-03-11T13:07:02ZengFrontiers Media S.A.Frontiers in Veterinary Science2297-17692024-03-011110.3389/fvets.2024.13466831346683Ruminal inocula with distinct fermentation profiles differentially affect the in vitro fermentation pattern of a commercial algal blendCátia S. C. Mota0Margarida R. G. Maia1Inês M. Valente2Inês M. Valente3Ana R. J. Cabrita4António J. M. Fonseca5REQUIMTE, LAQV, ICBAS, School of Medicine and Biomedical Sciences, University of Porto, Porto, PortugalREQUIMTE, LAQV, ICBAS, School of Medicine and Biomedical Sciences, University of Porto, Porto, PortugalREQUIMTE, LAQV, ICBAS, School of Medicine and Biomedical Sciences, University of Porto, Porto, PortugalREQUIMTE, LAQV, Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, Porto, PortugalREQUIMTE, LAQV, ICBAS, School of Medicine and Biomedical Sciences, University of Porto, Porto, PortugalREQUIMTE, LAQV, ICBAS, School of Medicine and Biomedical Sciences, University of Porto, Porto, PortugalThe in vitro rumen batch technique is widely used for screening novel feed sources; however, it remains unclear to what extent the in vitro fermentability of non-conventional feed sources is affected by non-adapted ruminal inocula. Thus, in this study, we evaluated the effects of distinct ruminal inocula on the in vitro fermentation parameters of a sustainable non-conventional feed, a commercially available algal blend composed of microalgae (Chlorella vulgaris and Nannochloropsis oceanica) and seaweeds (Ulva sp. and Gracilaria gracilis). First, four late-lactation Holstein cows were fed four forage-based diets varying only in the proportions of basal forage (100% corn silage, 70% corn silage and 30% haylage, 30% corn silage and 70% haylage, and 100% haylage) in a 4 × 4 Latin square design with the last square omitted. After 3 weeks of adaptation, haylage-based diets resulted in ruminal fermentation parameters distinct from those promoted by corn silage-based diets, as reflected in increased pH, ammonia-N contents, and acetate proportions. Individual ruminal fluids derived from each of the four diets were further used as inocula in in vitro incubations. Here, a 1:1 mixture of corn silage and haylage was supplemented with 0, 5, 10, or 15% algal blend and incubated with each inoculum for 24 h in a 4 × 4 factorial design. Total gas and methane production decreased with inocula from cows fed haylage-based diets and with increasing algal blend supplementation levels. The fermentation pH increased and the ammonia-N contents decreased with inocula from cows fed haylage-based diets; however, these parameters were not affected by algal blend inclusion levels. The interaction between the ruminal inoculum source and the algal blend supplementation level affected the total volatile fatty acids (VFA) and the proportions of most individual VFA. Total VFA production decreased with increasing algal supplementation levels, particularly with inocula from cows fed 30% corn silage and 70% haylage; the acetate, propionate, and valerate proportions were only affected by algal blend levels under incubation with 100% corn silage inocula. Overall, our findings highlight the importance of the ruminal inoculum source when assessing the fermentability of non-conventional feed as well as the potential of the algal blend as a natural modulator of ruminal fermentation.https://www.frontiersin.org/articles/10.3389/fvets.2024.1346683/fullalgal blenddairy cowinoculain vitrofermentationrumen
spellingShingle Cátia S. C. Mota
Margarida R. G. Maia
Inês M. Valente
Inês M. Valente
Ana R. J. Cabrita
António J. M. Fonseca
Ruminal inocula with distinct fermentation profiles differentially affect the in vitro fermentation pattern of a commercial algal blend
Frontiers in Veterinary Science
algal blend
dairy cow
inocula
in vitro
fermentation
rumen
title Ruminal inocula with distinct fermentation profiles differentially affect the in vitro fermentation pattern of a commercial algal blend
title_full Ruminal inocula with distinct fermentation profiles differentially affect the in vitro fermentation pattern of a commercial algal blend
title_fullStr Ruminal inocula with distinct fermentation profiles differentially affect the in vitro fermentation pattern of a commercial algal blend
title_full_unstemmed Ruminal inocula with distinct fermentation profiles differentially affect the in vitro fermentation pattern of a commercial algal blend
title_short Ruminal inocula with distinct fermentation profiles differentially affect the in vitro fermentation pattern of a commercial algal blend
title_sort ruminal inocula with distinct fermentation profiles differentially affect the in vitro fermentation pattern of a commercial algal blend
topic algal blend
dairy cow
inocula
in vitro
fermentation
rumen
url https://www.frontiersin.org/articles/10.3389/fvets.2024.1346683/full
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