Prediction of reproductive performance of ewes based on the early production data, ewe birth rank, dam age, and dam birth rank
<p>This research aimed to analyze whether ewes' total reproductive performance up to the fourth year of life (RP4) can be predicted based on the data available at an early stage of a ewe's productive life. The RP4 of 133 Romanov ewes was measured in terms of the total number of lambs...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2023-03-01
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| Series: | Archives Animal Breeding |
| Online Access: | https://aab.copernicus.org/articles/66/145/2023/aab-66-145-2023.pdf |
| Summary: | <p>This research aimed to analyze whether ewes' total reproductive performance
up to the fourth year of life (RP4) can be predicted based on the data
available at an early stage of a ewe's productive life. The RP4 of 133
Romanov ewes was measured in terms of the total number of lambs born per ewe
(TNLE) and total birth weight of lambs per ewe (TBLE). Multiple regression
was used to analyze whether early reproductive performance indicators (first
litter size – FLS, age at first lambing – AFL, first lambing interval –
FLI), ewe birth rank, dam age, and dam birth rank can be used as the
predictors of RP4. Predicted <span class="inline-formula"><i>R</i><sup>2</sup></span> and 95 % prediction intervals were
used as indicators of the precision of prediction. Average TNLE and TBLE at
the end of fourth year of ewe life were 11.84 lambs and 37.96 kg, respectively.
FLS and FLI significantly (<span class="inline-formula"><i>P</i><0.05</span>) influenced TNLE and TBLE, while
AFL was not a significant (<span class="inline-formula"><i>P</i>>0.05</span>) variable. Ewes with shorter
FLI had significantly (<span class="inline-formula"><i>P</i><0.05</span>) higher TNLE (10.94 lambs) and TBLE
(36.17 kg) than ewes with long FLI (TNLE <span class="inline-formula">=</span> 9.12 lambs and TBLE <span class="inline-formula">=</span> 28.05 kg).
<span class="inline-formula"><i>R</i><sup>2</sup></span> predicted for TNLE and TBLE was 7.54 % and 11.49 %,
respectively. The ewe's birth rank and the dam's birth rank significantly
(<span class="inline-formula"><i>P</i><0.05</span>) influenced TNLE and TBLE. Ewes born as singletons and ewes
from singleton-born dams had significantly (<span class="inline-formula"><i>P</i><0.05</span>) lower TNLE and
TBLE than ewes born as triplets and ewes from triplet-born dams. <span class="inline-formula"><i>R</i><sup>2</sup></span>
predicted for TNLE was 16.76 %, and 25.69 % for TBLE. FLS and FLI are
better predictors of RP4 than AFL. The birth rank of ewe and dam also proved
significant predictors of RP4. For both sets of predictors (early
reproductive indicators and birth rank data), low values of <span class="inline-formula"><i>R</i><sup>2</sup></span>
predicted indicate that precise prediction of RP4 cannot be made.</p> |
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| ISSN: | 0003-9438 2363-9822 |