Effects of service ram on litter size in Romanov sheep

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00027014%3A_____%2F16%3AN0000119" target="_blank" >RIV/00027014:_____/16:N0000119 - isvavai.cz</a>

Alternative codes found

RIV/60460709:41210/16:72325

Result on the web

<a href="http://www.vuzv.cz/sites/File/_privat/16120.pdf" target="_blank" >http://www.vuzv.cz/sites/File/_privat/16120.pdf</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.smallrumres.2016.05.018" target="_blank" >10.1016/j.smallrumres.2016.05.018</a>

Result language

angličtina

Original language name

Effects of service ram on litter size in Romanov sheep

Original language description

The objective was to examine and quantify the effects of factors acting during the mating period (service ram, mating group) on subsequent litter size in the highly prolific Romanov breed of sheep and to propose models for the potential inclusion of this effect in mixed model equations for breeding value estimation. The basic model fitted to litter size was a single-trait repeatability animal model with fixed effect of ewe age and random effects of contemporary groups of ewes during lambing, direct additive genetic effect of ewe, permanent environmental effect of ewe and random residual. 8 modifications of the basic model examined various combinations of mating effects, contemporary group of ewes during mating and additive genetic and permanent environmental effect of service ram. When the service ram effect was analyzed without inclusion of the population relationship matrix in the model, the proportion of variance attributable to service ram was 0.081. When the relationship matrix was included in the analysis, however, service ram heritability estimates varied from 0.046 to 0.10, depending upon whether ram is permanent environmental effect, a harem effect or both were included in model. Models containing the additive genetic effect of service ram had slightly lower proportions of residual variance than models lacking this effect. Including effects of mating in the model favourably decreased deviance information criterion. Means of estimated BVs by year of birth increased across the 22 years from about 0.45-0.60 lambs per litter for female fertility and from 0.55 to 0.59 lambs per litter for BV male contribution on litter size, with only small differences among models. Results from present study demonstrate that service rams in Romanov sheep have a clearly detectable influence on litter size of their mates. Genetic parameter estimates indicate that direct selection on the service ram effect could increase litter size

Czech name

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Czech description

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Type

J_x - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)

CEP classification

GI - Farm animal breeding and farm animal pedigree breeding

OECD FORD branch

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Project

<a href="/en/project/QJ1510139" target="_blank" >QJ1510139: Nation-wide information system of genetic evaluation of farm animals</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2016

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Small Ruminant Research

ISSN

0921-4488

e-ISSN

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Volume of the periodical

141

Issue of the periodical within the volume

August

Country of publishing house

NL - THE KINGDOM OF THE NETHERLANDS

Number of pages

7

Pages from-to

56-62

UT code for WoS article

000382274000011

EID of the result in the Scopus database

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