| The effect of harvesting strategy of grass silage on digestion and nutrient supply in dairy cows. | |
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MedLine Citation:
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PMID: 20630241 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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This study examined the effects of primary growth (PG) and regrowth (RG) timothy-meadow fescue silages harvested at 2 stages of growth on feed intake, cell wall digestion and ruminal passage kinetics in lactating dairy cows. Four dairy cows equipped with rumen cannulas were used in a study designed as a 4 x 4 Latin square with 21-d periods. The experimental silages were offered ad libitum with 8 kg/d of concentrate. Ruminal digestion and passage kinetics were assessed by the rumen evacuation technique. Silages of PG were on average more digestible than RG silages. The concentration of neutral detergent fiber (NDF) and indigestible NDF (iNDF) increased and the concentration of digestible organic matter in dry matter (DM) of silages decreased with advancing maturity in PG and RG. Cows consumed more feed DM, energy, and protein and produced more milk when fed PG diets rather than RG diets. Delaying the harvest decreased DM intake and milk production in PG and RG. There were no differences between PG and RG in rumen pH, ammonia N, or total volatile fatty acid concentrations. The intake of N, omasal canal flow of total nonammonia N and microbial N, excretion of N in feces, and ruminal true digestibility of N were higher for PG than for RG diets. The efficiency of microbial N synthesis was not different between PG and RG. Intake and omasal canal flow of organic matter, NDF, and potentially digestible NDF (pdNDF) were higher in PG than in RG. Whole-diet digestibility of organic matter, NDF, or pdNDF in the rumen or in the total tract was not different between PG and RG despite the higher digestibility of PG silages measured in sheep. Rumen pool sizes of crude protein and iNDF were lower for PG diets, whereas the pool size of pdNDF was higher for PG diets than for RG diets. The rate of passage of iNDF was higher for PG diets than for RG diets, with no difference between them in rate of digestion or passage of pdNDF. The lower milk production in cows fed regrowth grass silages compared with primary growth silages could be attributed to the lower silage DM intake potential. Chemical composition of the silages, rumen fill, digestion and passage kinetics of NDF, or the ratio of protein to energy in absorbed nutrients could not explain the differences in DM intake between silages made from primary and regrowth grass. |
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Authors:
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K Kuoppala; M Rinne; S Ahvenjärvi; J Nousiainen; P Huhtanen |
Publication Detail:
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Type: Journal Article |
Journal Detail:
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Title: Journal of dairy science Volume: 93 ISSN: 1525-3198 ISO Abbreviation: J. Dairy Sci. Publication Date: 2010 Jul |
Date Detail:
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Created Date: 2010-07-15 Completed Date: 2010-12-14 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 2985126R Medline TA: J Dairy Sci Country: United States |
Other Details:
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Languages: eng Pagination: 3253-63 Citation Subset: IM |
Copyright Information:
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Copyright (c) 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved. |
Affiliation:
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MTT Agrifood Research Finland, Animal Production Research, FI-31600 Jokioinen, Finland. kaisa.kuoppala@mtt.fi |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animal Feed
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analysis Animal Nutritional Physiological Phenomena* Animals Bacteria / metabolism Cattle / metabolism* Dairying Digestion / physiology* Fatty Acids, Volatile / analysis Female Fermentation / physiology Gastrointestinal Contents / chemistry, microbiology Hydrogen-Ion Concentration Nitrogen / analysis Poaceae / chemistry, metabolism* Rumen / metabolism* Silage* |
| Chemical | |
Reg. No./Substance:
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0/Fatty Acids, Volatile; 7727-37-9/Nitrogen |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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