Relationships between body reserve dynamics and rearing performances in meat ewes1
| Autor: | Dominique Hazard, Fabien Carrière, Eliel Gonzalez-Garcia, Sébastien Douls, Tiphaine Macé, Didier Foulquié |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Litter (animal)
Male Meat Litter Size 040301 veterinary sciences Production cycle Weaning Biology Breeding Models Biological 0403 veterinary science Animal science Body condition score Pregnancy Genetics Animals Cluster Analysis Least-Squares Analysis Sheep Domestic 2. Zero hunger Domestic sheep reproduction Body Weight 0402 animal and dairy science Age Factors Animal Genetics and Genomics 04 agricultural and veterinary sciences General Medicine 040201 dairy & animal science Sheep flock Phenotype Animal Science and Zoology Female Flock France Sex ratio Food Science |
| Zdroj: | J Anim Sci |
| ISSN: | 1525-3163 |
| Popis: | The main objective of this work was to study the relationships between body reserve (BR) dynamics and rearing performance (PERF) traits in ewes from a Romane meat sheep flock managed extensively on “Causse” rangelands in the south of France. Flock records were used to generate data sets covering 14 lambing years (YR). The data set included 1,146 ewes with 2 ages of first lambing (AGE), 3 parities (PAR), and 4 litter sizes (LS). Repeated measurements of the BW and BCS were used as indicators of BR. The ewe PERF traits recorded were indirect measurements for maternal abilities and included prolificacy, litter weight and lamb BW at lambing and weaning, ADG at 1, 2, and 3 mo after lambing, and litter survival from lambing to weaning. The effects of different BW and BCS trajectories (e.g., changes in BW and BCS across the production cycle), previously been characterized in the same animals, on PERF traits were investigated. Such trajectories reflected different profiles at the intraflock level in the dynamics of BR mobilization–accretion cycles. Genetic relationships between BR and PERF traits were assessed. All the fixed variables considered (i.e., YR, AGE, PAR, LS, and SEX ratio of the litter) have significant effects on the PERF traits. Similarly, BW trajectories had an effect on the PERF traits across the 3 PARs studied, particularly during the first cycle (PAR 1). The BCS trajectories only affected prolificacy, lamb BW at birth, and litter survival. Most of the PERF traits considered here showed moderate heritabilities (0.17–0.23) except for prolificacy, the lamb growth rate during the third month and litter survival which showed very low heritabilities. With exception of litter survival and prolificacy, ewe PERF traits were genetically, strongly, and positively correlated with BW whatever the physiological stage. A few weak genetic correlations were found between BCS and PERF traits. As illustrated by BW and BCS changes over time, favorable genetic correlations were found, even if few and moderate, between BR accretion or mobilization and PERF traits, particularly for prolificacy and litter weight at birth. In conclusion, our results show significant relationships between BR dynamics and PERF traits in ewes, which could be considered in future sheep selection programs aiming to improve robustness. |
| Databáze: | OpenAIRE |
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