Factors affecting birth weight in sheep: maternal environment
| Autor: | Peter J. Buttery, Z Daniel, David S. Gardner, Michael E. Symonds |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Litter (animal)
Embryology medicine.medical_specialty Litter Size Maternal Nutritional Physiological Phenomena media_common.quotation_subject Birth weight Gestational Age Breeding Environment Biology Article Endocrinology Animal science Pregnancy medicine Animals Birth Weight Sheep Domestic media_common Obstetrics Body Weight Obstetrics and Gynecology Gestational age Cell Biology Animal husbandry medicine.disease Parity Animals Newborn Reproductive Medicine Infertility Pregnancy Animal Gestation Female Reproduction Energy Intake |
| Zdroj: | Reproduction. 133:297-307 |
| ISSN: | 1741-7899 1470-1626 |
| Popis: | Knowledge of factors affecting variation in birth weight is especially important given the relationship of birth weight to neonatal and adult health. The present study utilises two large contemporary datasets in sheep of differing breeds to explore factors that influence weight at term. For dataset one (Study 1;n=154 Blue-faced Leicester×Swaledale (Mule) and 87 Welsh Mountain ewes, 315 separate cases of birth weight), lamb birth weight as the outcome measure was related to maternal characteristics and individual energy intake of the ewe during specified periods of gestation, i.e. early (1–30 days; term ~147 days gestation), mid (31–80 days) or late (110–147 days) pregnancy. For dataset two (Study 2;n=856 Mule ewes and 5821 cases of birth weight), we investigated using multilevel modelling the influence of ewe weight, parity, barrenness, lamb sex, litter size, lamb mortality and year of birth on lamb birth weight. For a subset of these ewes (n=283), the effect of the ewes’ own birth weight was also examined. Interactions between combinations of variables were selectively investigated. Litter size, as expected, had the single greatest influence on birth weight with other significant effects being year of birth, maternal birth weight, maternal nutrition, sex of the lamb, ewe barrenness and maternal body composition at mating. The results of the present study have practical implications not only for sheep husbandry but also for the increased knowledge of factors that significantly influence variation in birth weight; as birth weight itself has become a significant predictor of later health outcomes. |
| Databáze: | OpenAIRE |
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