Linked Life Data

12512609

Source:http://linkedlifedata.com/resource/pubmed/id/12512609

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2003-1-6
pubmed:abstractText
The kinetics of dry matter intake, raw milk yield, milk fat yield, and body weight of 140 treatment groups of cows reported in 37 articles published between 1959 and 1999 were collected in a database. The majority of these experiments were performed with Holstein-Friesian cows (primiparous: n = 51, multiparous: n = 89). Animals were fed with forages and concentrates, offered separately (n = 98) or as a total mixed ration (n = 42). Empty body weight was calculated assuming that an increase of 1 kg in dry matter intake corresponded to an increase of 4 kg in gastrointestinal tract content. Each kinetic, denoted Y, was fitted with the model proposed by Grossman (1999) for raw milk yield. This model allowed the partitioning of the kinetic into three stages (early, middle, and late stages of lactation), each characterized by its own linear tendency. Kinetics were therefore summarized with parameter estimates of the model: the plateau value of Y in middle stage, the slopes of Y in early and late stages, and the weeks of start and end of the middle stage. The following additional variables were also calculated: the total increase of Y in early stage, the extrapolated value of Y at calving, and the persistency of Y defined as the duration of the middle stage. Variability of these parameters for each kinetic across treatment groups was examined through mixed models including the year of publication as covariate, parity as a fixed between-group factor, and trial as a random factor. Correlations between parameters within a Y-kinetic and between different Y-kinetics were calculated by parity group and feed allocation system. Finally we propose predictive models which emphasized (1) the effect of empty body weight at calving on the depletion of empty body weight in early lactation, (2) the incidence of the kinetic of dry matter intake on the kinetic of raw milk yield in middle and late stages of lactation, and (3) the relationships between the kinetics of raw milk yield and milk fat yield in middle and late stages of lactation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0022-0302
pubmed:author
pubmed:issnType
Print
pubmed:volume
85
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3363-81
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Metaanalysis of input/output kinetics in lactating dairy cows.
pubmed:affiliation
UMR INRA INA P-G, Physiologie de la Nutrition et Alimentation, 16 rue Claude Bernard, 75231 Paris Cedex 05, France.
pubmed:publicationType
Journal Article, Meta-Analysis