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Registro Completo |
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Biblioteca(s): |
Embrapa Caprinos e Ovinos. |
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Data corrente: |
01/08/1992 |
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Data da última atualização: |
02/10/2023 |
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Autoria: |
WILLINGHAM, M.; SHELTON, M.; THOMPSON, P. |
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Título: |
An assessment of reproductive wastage in sheep. |
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Ano de publicação: |
1986 |
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Fonte/Imprenta: |
Theriogenology, v. 26, n. 2, p. 179-188, 1986. |
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DOI: |
https://doi.org/10.1016/0093-691X(86)90022-1 |
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Idioma: |
Inglês |
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Conteúdo: |
Abstract: Reproductive wastage was evaluated by relating ovulation rate to lambs born or raised in range finewool ewes over a ten-year period. The results indicate that reproductive losses are of large magnitude and that these losses are concentrated in the period of ovulation to implantation and in death losses of lambs born. In this study, 33.5% of the potential lamb crop was lost in the early period. Multiple ovulating ewes showed the greatest embryonic loss. The data do not deviate from the binomial distribution, thus suggesting that these losses are largely due to chance. Further work is indicated in the first seventeen days after ovulation to examine losses due to fertilization failure, chromosomal abnormalities, and implantation failure. Abortion or absorption of the fetus was indicated in only 4% of the ewes sampled. An average of 16% of the potential lamb crop was lost from birth to weaning, with 73% of these losses occurring in the first few weeks. Management practices need to be developed to reduce these losses, and these would be expected to vary from one producer to the next depending on conditions. Increasing ovulation rate is one possible method of improving reproductive efficiency, as results of this study indicate that for each unit increase in ovulation rate, there is an increase of 0.52, 0.46, 0.33, and 0.23 in the average number of embryos surviving, lambs born, lambs marked and lambs weaned, respectively. |
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Thesaurus Nal: |
Ewes; Mortality; Pregnancy; Reproduction; Reproductive efficiency; Sheep. |
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Categoria do assunto: |
L Ciência Animal e Produtos de Origem Animal |
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Marc: |
LEADER 02054naa a2200229 a 4500
001 1521200
005 2023-10-02
008 1986 bl uuuu u00u1 u #d
024 7 $ahttps://doi.org/10.1016/0093-691X(86)90022-1$2DOI
100 1 $aWILLINGHAM, M.
245 $aAn assessment of reproductive wastage in sheep.
260 $c1986
520 $aAbstract: Reproductive wastage was evaluated by relating ovulation rate to lambs born or raised in range finewool ewes over a ten-year period. The results indicate that reproductive losses are of large magnitude and that these losses are concentrated in the period of ovulation to implantation and in death losses of lambs born. In this study, 33.5% of the potential lamb crop was lost in the early period. Multiple ovulating ewes showed the greatest embryonic loss. The data do not deviate from the binomial distribution, thus suggesting that these losses are largely due to chance. Further work is indicated in the first seventeen days after ovulation to examine losses due to fertilization failure, chromosomal abnormalities, and implantation failure. Abortion or absorption of the fetus was indicated in only 4% of the ewes sampled. An average of 16% of the potential lamb crop was lost from birth to weaning, with 73% of these losses occurring in the first few weeks. Management practices need to be developed to reduce these losses, and these would be expected to vary from one producer to the next depending on conditions. Increasing ovulation rate is one possible method of improving reproductive efficiency, as results of this study indicate that for each unit increase in ovulation rate, there is an increase of 0.52, 0.46, 0.33, and 0.23 in the average number of embryos surviving, lambs born, lambs marked and lambs weaned, respectively.
650 $aEwes
650 $aMortality
650 $aPregnancy
650 $aReproduction
650 $aReproductive efficiency
650 $aSheep
700 1 $aSHELTON, M.
700 1 $aTHOMPSON, P.
773 $tTheriogenology$gv. 26, n. 2, p. 179-188, 1986.
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Registro original: |
Embrapa Caprinos e Ovinos (CNPC) |
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