Search

In rabbits, ovulation rate is, together with prenatal survival, one of the main limiting factors for litter size. Both components are affected by several factors related to females and their environment. Thus, understanding these components and their factors of variation is key in designing diets, optimisation of reproductive performance and genetic selection. In this review, authors summarise the main components of litter size and their environmental factors of variation. Genetic factors and the main results of genetic selection programmes on components of litter size are also summarised. In this regard, a negative effect of dietary restriction and reduced day light hours is found, as well as a positive effect of body condition, parity order and age of female on ovulation rate. However, an increase in deterioration of oocyte quality has been reported as ovulation rate increases, leading to decreased embryonic and foetal survival. Dietary restriction and heat stress also have a negative effect on embryonic and foetal survival, increasing the failures during gestation while good vascularisation and enough available space in uterine horn are keys to embryonic and foetal survival. Ovulation rate was proposed as indirect selection criterion to improve litter size due to higher heritability. However, this selection was relevant, but it did not modify litter size because of an increase in prenatal mortality. Uterine capacity has been directly related to prenatal survival, although its selection has also been unsuccessful in increasing litter size. [ABSTRACT FROM AUTHOR]

Copyright of Egyptian Poultry Science Journal is the property of Egyptian Poultry Science Association and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

References for the research study "Patent Retrieval" are presented.

A bibliography on the subject of blog search is presented which includes the PhD thesis "Probability models for information retrieval based on divergence from randomness" by G. Amati, the article "A taxonomy of web search" by A. Broder and the paper "Large-scale sentiment analysis for news and blogs" by N. Godbole, M. Srinivasaiah and S. Skiena.