| The crossbred sire: experimental results for sheep. | |
| | |
MedLine Citation:
|
PMID: 3301776 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Crossbreeding of sheep is practiced to exploit simultaneously the use of additive and nonadditive genetic effects. The goal is to achieve optimal levels of performance appropriate for defined systems of sheep production and marketing. Although the beneficial effects of individual and maternal heterosis on sheep production have been well documented and widely implemented, considerably less is known about the effects of paternal heterosis. Limited evidence suggests that crossbred rams are more sexually aggressive and exhibit greater testicular growth than do purebred rams. Average estimates of paternal heterosis effects were 1.4, -.7 and 2.3% for seasonal fertility, prolificacy and preweaning survival, respectively. The average effect of paternal heterosis on fertility during spring breeding was 29.5%. Progeny of crossbred and purebred sires were similar in birth weight, weaning weight and postweaning growth rate and in phenotypic variation for these growth traits. However, favorable paternal heterosis effects need not exist to warrant the use of crossbred sires. Composite or F1 sires can be used as an effective method to manage the composition of additive breed effects. For example, varying proportions of germ plasm from highly prolific breeds such as the Finnsheep and Romanov can be realized through the use of crossbred sires to set reproductive rates at desired levels. Crossbred sires may be used to a greater extent to optimize additive breed effects than to exploit effects of paternal heterosis. The role of composite breeds in managing both additive and nonadditive effects is discussed. |
| | |
Authors:
|
K A Leymaster |
Related Documents
:
|
6868176 - Hyperbaric exposure during pregnancy in sheep: staged and rapid decompression. 6910716 - Effects of pregnancy on the febrile responses in sheep. 8350336 - Higher relative risk of spondyloarthropathies among b27 positive indonesian chinese tha... 1220656 - Wimmera rye grass toxicity in western australia. 9408876 - High-order multiple pregnancies complicated by hellp syndrome. a report of four cases w... 22102516 - Predictive value of sequential models of the uterine artery doppler in pregnancies at h... |
Publication Detail:
|
Type: Journal Article; Review |
Journal Detail:
|
Title: Journal of animal science Volume: 65 ISSN: 0021-8812 ISO Abbreviation: J. Anim. Sci. Publication Date: 1987 Jul |
Date Detail:
|
Created Date: 1987-09-22 Completed Date: 1987-09-22 Revised Date: 2003-11-14 |
Medline Journal Info:
|
Nlm Unique ID: 8003002 Medline TA: J Anim Sci Country: UNITED STATES |
Other Details:
|
Languages: eng Pagination: 110-6 Citation Subset: IM |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Animals Body Weight Crosses, Genetic* Fertility Hybrid Vigor Male Sheep / genetics* |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Factors affecting the onset of inner ear function.
Next Document: The crossbred sire: experimental results for swine.