Document Detail


Effect of pregrazing herbage mass on methane production, dry matter intake, and milk production of grazing dairy cows during the mid-season period.
MedLine Citation:
PMID:  20855032     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Increasing milk production from pasture while increasing grass dry matter intake (GDMI) and lowering methane (CH(4)) emissions are key objectives of low-cost dairy production systems. It was hypothesized that offering swards of low herbage mass with increased digestibility leads to increased milk output. A grazing experiment was undertaken to investigate the effects of varying levels of HM on CH(4) emissions, GDMI and milk production of grazing dairy cows during the mid-season grazing period (June to July). Prior to the experiment, 46 Holstein-Friesian dairy cows (46 d in milk) were randomly assigned to 1 of 2 treatments (n=23) in a randomized block design. The 2 treatments consisted of 2 target pregrazing HM: 1,000 kg of dry matter (DM)/ha (low herbage mass, LHM) or 2,200 kg of DM/ha (high herbage mass, HHM). The experimental period lasted 2 mo from June 1 until July 31. Within the experimental period, there were 2 measurement periods, measurement 1 (M1) and measurement 2 (M2), where CH(4) emissions, GDMI, and milk production were measured. Mean herbage mass throughout the measurement periods was 1,075 kg of DM/ha and 1,993 kg of DM/ha for the LHM and HHM treatments, respectively. Grass quality in terms of organic matter digestibility was significantly higher for the LHM treatment in M2 (+12 g/kg of DM). In M1, the effect of herbage mass on grass quality was approaching significance in favor of the LHM treatment. Herbage mass did not significantly affect milk production during the measurement periods. Cows grazing the LHM swards had increased GDMI in M1 (+1.5 kg of DM) compared with cows grazing the HHM swards; no difference in GDMI was observed in M2. Grazing HHM swards increased CH(4) production per cow per day (+42 g), per kilogram of milk yield (+3.5 g/kg of milk), per kilogram of milk solids (+47 g/kg of milk solids), and per kilogram of GDMI (+3.1 g/kg of GDMI) in M2. Cows grazing the HHM swards lost a greater proportion of their gross energy intake as CH(4) during both measurement periods (+0.9% and +1% for M1 and M2, respectively). It was concluded that grazing LHM swards would increase grass quality with a concurrent reduction in CH(4) emissions.
Authors:
C M Wims; M H Deighton; E Lewis; B O'Loughlin; L Delaby; T M Boland; M O'Donovan
Publication Detail:
Type:  Journal Article; Randomized Controlled Trial; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of dairy science     Volume:  93     ISSN:  1525-3198     ISO Abbreviation:  J. Dairy Sci.     Publication Date:  2010 Oct 
Date Detail:
Created Date:  2010-09-21     Completed Date:  2010-12-30     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  2985126R     Medline TA:  J Dairy Sci     Country:  United States    
Other Details:
Languages:  eng     Pagination:  4976-85     Citation Subset:  IM    
Copyright Information:
Copyright © 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Affiliation:
Grassland Science Research Department, Animal and Grassland Research and Innovation Centre, Teagasc, Moorepark, Fermoy, Co. Cork, Ireland.
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MeSH Terms
Descriptor/Qualifier:
Animal Feed
Animal Nutritional Physiological Phenomena
Animals
Cattle / physiology*
Diet / veterinary*
Eating*
Female
Lactation / physiology*
Methane / biosynthesis*
Milk / chemistry,  secretion
Poaceae / metabolism*
Seasons
Time Factors
Chemical
Reg. No./Substance:
74-82-8/Methane

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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