Linked Life Data

3711408

Source:http://linkedlifedata.com/resource/pubmed/id/3711408

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1986-7-7
pubmed:abstractText
A total of 253 heifers bred at first estrus after 350 d of age (350-d breeding age group) and 249 contemporary heifers bred at first estrus after 462 d of age (462-d breeding age group) were used to study the effects of age at first breeding on productive and reproductive performances of first lactation heifers. Heifers of both breeding age groups were subject to similar feeding and management practices. The average age at first calving was 698 d for the 350-d breeding group and 796 d for the 462-d breeding group. Although not statistically significant, heifers of the 462-d breeding group tended to have a higher conception rate at first service (47 vs. 38%) and fewer days between first service and conception (39 vs. 44 d) than those of the 350-d breeding age group. Breeding heifers as early as 350 d of age has no adverse effects on calving ease or retained placenta but does result in calves 1.2 kg lighter at birth. Heifers of the 350-d breeding group had lower milk, protein, and fat yields at both 168 and 308 d of first lactation than those of the 462-d breeding group. A 1-d reduction in age at first calving decreased 308-d milk yield by 2.01 kg for the 350-d breeding group as compared with 4.74 kg for the 462-d breeding group.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0022-0302
pubmed:author
pubmed:issnType
Print
pubmed:volume
69
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
760-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
Production and reproduction of early and late bred dairy heifers.
pubmed:publicationType
Journal Article, Comparative Study