Effects of feeding level and NDF content of grass-clover silages on chewing activity, fecal particle size and NDF digestibility in dairy heifers
The objective of this study was to assess effects of feed intake and NDF content of highly digestible grass-clover silage on chewing behavior, fecal particle size distribution and apparent digestibility in restrictively fed heifers. Four grass-clover silages (Lolium perenne, Trifolium pratense and T...
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| Format: | Article |
| Language: | English |
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Elsevier
2014-01-01
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| Series: | Animal |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S1751731114002055 |
| _version_ | 1819151100820848640 |
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| author | A.K.S. Schulze M.R. Weisbjerg P. Nørgaard |
| author_facet | A.K.S. Schulze M.R. Weisbjerg P. Nørgaard |
| author_sort | A.K.S. Schulze |
| collection | DOAJ |
| description | The objective of this study was to assess effects of feed intake and NDF content of highly digestible grass-clover silage on chewing behavior, fecal particle size distribution and apparent digestibility in restrictively fed heifers. Four grass-clover silages (Lolium perenne, Trifolium pratense and Trifolium repens) were harvested in 2009 at different regrowth stages, resulting in silages with NDF contents of 312, 360, 371 and 446 g/kg dry matter (DM), respectively. Four rumen-fistulated Jersey heifers (343±32 kg BW) were fed silage at 90% of ad libitum levels in a 4×4 Latin square design, replicated with further restricted feeding levels (50%, 60%, 70% or 80% of ad libitum) in a balanced 4×4×4 Greco-Latin square design. Eating activity was estimated from test meal observations, while rumination activity was estimated from jaw movements logged by a jaw recorder system. Total tract digestibility was estimated from chromic oxide marker and fecal spot sampling, and fecal particle size distribution in washed and freeze-dried particulate DM was determined by dry sieving (2.36, 1.0, 0.5, 0.212 and 0.106 mm, and bottom bowl). Higher NDF content of silage stimulated longer eating time per kg DM intake (P<0.001), while reduced feeding level caused a reduction in eating time per kg DM intake (P<0.001) and NDF (P<0.001). Rumination time per kg DM intake (P<0.01) increased with reduced feeding level, with less effect of feeding level at lower NDF contents (P<0.01) and more rumination with greater NDF content (P<0.01). Relative to NDF intake, rumination time increased with greater NDF content (P<0.01), at a higher rate with reduced feeding level (P<0.05). Digestibility of potentially digestible NDF (DNDF) decreased with greater NDF content (P<0.001) and increased with reduced feeding level (P<0.05). Increasing NDF content resulted in more particulate DM in feces (g/kg DM; P<0.05) and larger mean particle size (P<0.001). In conclusion, feeding heifers with grass-clover silages of decreasing NDF content increased chewing time relative to NDF intake, reduced mean fecal particle size, and increased DNDF digestibility. Restricting feeding level made heifers eat for a shorter time period while rumination and total chewing was increased, causing the ratio between eating and rumination time to decrease with lower intake of forage fiber. Particle size reduction and digestibility depended mostly on changes in NDF content, especially the indigestible NDF content. |
| first_indexed | 2024-12-22T14:28:02Z |
| format | Article |
| id | doaj.art-c643a44702d74198a694a701b69b5e8c |
| institution | Directory Open Access Journal |
| issn | 1751-7311 |
| language | English |
| last_indexed | 2024-12-22T14:28:02Z |
| publishDate | 2014-01-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Animal |
| spelling | doaj.art-c643a44702d74198a694a701b69b5e8c2022-12-21T18:22:49ZengElsevierAnimal1751-73112014-01-0181219451954Effects of feeding level and NDF content of grass-clover silages on chewing activity, fecal particle size and NDF digestibility in dairy heifersA.K.S. Schulze0M.R. Weisbjerg1P. Nørgaard2Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 1870 Frederiksberg C, DenmarkDepartment of Animal Science, AU-Foulum, Faculty of Science and Technology, Aarhus University, 8830 Tjele, DenmarkDepartment of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 1870 Frederiksberg C, DenmarkThe objective of this study was to assess effects of feed intake and NDF content of highly digestible grass-clover silage on chewing behavior, fecal particle size distribution and apparent digestibility in restrictively fed heifers. Four grass-clover silages (Lolium perenne, Trifolium pratense and Trifolium repens) were harvested in 2009 at different regrowth stages, resulting in silages with NDF contents of 312, 360, 371 and 446 g/kg dry matter (DM), respectively. Four rumen-fistulated Jersey heifers (343±32 kg BW) were fed silage at 90% of ad libitum levels in a 4×4 Latin square design, replicated with further restricted feeding levels (50%, 60%, 70% or 80% of ad libitum) in a balanced 4×4×4 Greco-Latin square design. Eating activity was estimated from test meal observations, while rumination activity was estimated from jaw movements logged by a jaw recorder system. Total tract digestibility was estimated from chromic oxide marker and fecal spot sampling, and fecal particle size distribution in washed and freeze-dried particulate DM was determined by dry sieving (2.36, 1.0, 0.5, 0.212 and 0.106 mm, and bottom bowl). Higher NDF content of silage stimulated longer eating time per kg DM intake (P<0.001), while reduced feeding level caused a reduction in eating time per kg DM intake (P<0.001) and NDF (P<0.001). Rumination time per kg DM intake (P<0.01) increased with reduced feeding level, with less effect of feeding level at lower NDF contents (P<0.01) and more rumination with greater NDF content (P<0.01). Relative to NDF intake, rumination time increased with greater NDF content (P<0.01), at a higher rate with reduced feeding level (P<0.05). Digestibility of potentially digestible NDF (DNDF) decreased with greater NDF content (P<0.001) and increased with reduced feeding level (P<0.05). Increasing NDF content resulted in more particulate DM in feces (g/kg DM; P<0.05) and larger mean particle size (P<0.001). In conclusion, feeding heifers with grass-clover silages of decreasing NDF content increased chewing time relative to NDF intake, reduced mean fecal particle size, and increased DNDF digestibility. Restricting feeding level made heifers eat for a shorter time period while rumination and total chewing was increased, causing the ratio between eating and rumination time to decrease with lower intake of forage fiber. Particle size reduction and digestibility depended mostly on changes in NDF content, especially the indigestible NDF content.http://www.sciencedirect.com/science/article/pii/S1751731114002055particle size distributiongrass-clover silagecowNDFchewing activity |
| spellingShingle | A.K.S. Schulze M.R. Weisbjerg P. Nørgaard Effects of feeding level and NDF content of grass-clover silages on chewing activity, fecal particle size and NDF digestibility in dairy heifers Animal particle size distribution grass-clover silage cow NDF chewing activity |
| title | Effects of feeding level and NDF content of grass-clover silages on chewing activity, fecal particle size and NDF digestibility in dairy heifers |
| title_full | Effects of feeding level and NDF content of grass-clover silages on chewing activity, fecal particle size and NDF digestibility in dairy heifers |
| title_fullStr | Effects of feeding level and NDF content of grass-clover silages on chewing activity, fecal particle size and NDF digestibility in dairy heifers |
| title_full_unstemmed | Effects of feeding level and NDF content of grass-clover silages on chewing activity, fecal particle size and NDF digestibility in dairy heifers |
| title_short | Effects of feeding level and NDF content of grass-clover silages on chewing activity, fecal particle size and NDF digestibility in dairy heifers |
| title_sort | effects of feeding level and ndf content of grass clover silages on chewing activity fecal particle size and ndf digestibility in dairy heifers |
| topic | particle size distribution grass-clover silage cow NDF chewing activity |
| url | http://www.sciencedirect.com/science/article/pii/S1751731114002055 |
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