Response of maiden ewes to the ‘ram effect’ is a robust management practice and a candidate selection trait for enhanced reproductive performance in drylands
Management of reproduction that relies on naturally based solutions is extremely important to counter the negative perception around hormone-based interventions. In Mediterranean latitudes and wider regions of non-tropical drylands, sheep do not normally ovulate during spring but exposure to a ram c...
| Main Authors: | , , , , , , , , |
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| Format: | Journal Article |
| Language: | Inglés |
| Published: |
Elsevier
2024
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| Subjects: | |
| Online Access: | https://hdl.handle.net/10568/159635 |
| _version_ | 1855524771389767680 |
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| author | Ben Salem, Imene Rouatbi, Mariem Mlika, Mariem Getachew, Tesfaye Govind, Ajit Haile, Aynalem Raggem, Mohamed Lahsoumi, Ridha Rekik, Mourad |
| author_browse | Ben Salem, Imene Getachew, Tesfaye Govind, Ajit Haile, Aynalem Lahsoumi, Ridha Mlika, Mariem Raggem, Mohamed Rekik, Mourad Rouatbi, Mariem |
| author_facet | Ben Salem, Imene Rouatbi, Mariem Mlika, Mariem Getachew, Tesfaye Govind, Ajit Haile, Aynalem Raggem, Mohamed Lahsoumi, Ridha Rekik, Mourad |
| author_sort | Ben Salem, Imene |
| collection | Repository of Agricultural Research Outputs (CGSpace) |
| description | Management of reproduction that relies on naturally based solutions is extremely important to counter the negative perception around hormone-based interventions. In Mediterranean latitudes and wider regions of non-tropical drylands, sheep do not normally ovulate during spring but exposure to a ram can induce oestrus and ovulation. This study assesses the response of maiden Barbarine ewes in drylands to the ‘ram effect’ during springtime and estimates the genetic parameters of this response. The study uses a database documenting, for 24 consecutive years, the response of nulliparous 18-month-old ewes when mated after stimulation by the ‘ram effect.’ In addition to the oestrous and fertility database, a pedigree database was also available. Nearly half of the maiden ewes responded to the ‘ram effect,’ while 24% exhibited spontaneous reproductive activity and displayed oestrus during the first 14 days following the introduction of rams. Nearly 5% of females did not exhibit oestrus, and these animals are proposed for early culling. Average annual values of Normalized Difference Vegetation Index (NDVI), reflecting vegetation cover, and the percent of maiden ewes spontaneously cycling were positively correlated (P = 0.006). Interestingly, NDVI was negatively correlated with the percentage of anoestrus females that did not respond to the ‘ram effect’ but exhibited oestrus beyond the hypothetical time frame commonly used to describe it. Average fertility was 82.8% and was significantly affected by mating year, live weight at mating, and the response to the ‘ram effect.’ The highest fertility (88.39%) was for females spontaneously cycling at the time of ram introduction, and the lowest (83.35%) was for females coming into oestrus beyond the time frame for a ram-induced oestrus and ovulation. Heritability from a univariate logit transformed analysis for fertility was 0.10 and the genetic correlation between fertility and the interval between ram introduction and oestrus was 0.26, suggesting that a shorter interval is associated with higher fertility. Thus, the interval between ram introduction and oestrus is a good candidate for selective breeding for high fertility of maiden ewes in drylands mated out-of-season using the ‘ram effect.’ |
| format | Journal Article |
| id | CGSpace159635 |
| institution | CGIAR Consortium |
| language | Inglés |
| publishDate | 2024 |
| publishDateRange | 2024 |
| publishDateSort | 2024 |
| publisher | Elsevier |
| publisherStr | Elsevier |
| record_format | dspace |
| spelling | CGSpace1596352026-01-22T02:07:19Z Response of maiden ewes to the ‘ram effect’ is a robust management practice and a candidate selection trait for enhanced reproductive performance in drylands Ben Salem, Imene Rouatbi, Mariem Mlika, Mariem Getachew, Tesfaye Govind, Ajit Haile, Aynalem Raggem, Mohamed Lahsoumi, Ridha Rekik, Mourad fertility ram effect heritability barbarine sheep sheep genetic trend Management of reproduction that relies on naturally based solutions is extremely important to counter the negative perception around hormone-based interventions. In Mediterranean latitudes and wider regions of non-tropical drylands, sheep do not normally ovulate during spring but exposure to a ram can induce oestrus and ovulation. This study assesses the response of maiden Barbarine ewes in drylands to the ‘ram effect’ during springtime and estimates the genetic parameters of this response. The study uses a database documenting, for 24 consecutive years, the response of nulliparous 18-month-old ewes when mated after stimulation by the ‘ram effect.’ In addition to the oestrous and fertility database, a pedigree database was also available. Nearly half of the maiden ewes responded to the ‘ram effect,’ while 24% exhibited spontaneous reproductive activity and displayed oestrus during the first 14 days following the introduction of rams. Nearly 5% of females did not exhibit oestrus, and these animals are proposed for early culling. Average annual values of Normalized Difference Vegetation Index (NDVI), reflecting vegetation cover, and the percent of maiden ewes spontaneously cycling were positively correlated (P = 0.006). Interestingly, NDVI was negatively correlated with the percentage of anoestrus females that did not respond to the ‘ram effect’ but exhibited oestrus beyond the hypothetical time frame commonly used to describe it. Average fertility was 82.8% and was significantly affected by mating year, live weight at mating, and the response to the ‘ram effect.’ The highest fertility (88.39%) was for females spontaneously cycling at the time of ram introduction, and the lowest (83.35%) was for females coming into oestrus beyond the time frame for a ram-induced oestrus and ovulation. Heritability from a univariate logit transformed analysis for fertility was 0.10 and the genetic correlation between fertility and the interval between ram introduction and oestrus was 0.26, suggesting that a shorter interval is associated with higher fertility. Thus, the interval between ram introduction and oestrus is a good candidate for selective breeding for high fertility of maiden ewes in drylands mated out-of-season using the ‘ram effect.’ 2024-11-01 2024-11-12T21:32:08Z 2024-11-12T21:32:08Z Journal Article https://hdl.handle.net/10568/159635 en Open Access application/pdf Elsevier Imene Ben Salem, Mariem Rouatbi, Mariem Mlika, Tesfaye Getachew, Ajit Govind, Aynalem Haile, Mohamed Raggem, Ridha Lahsoumi, Mourad Rekik. (1/11/2024). Response of maiden ewes to the ‘ram effect’ is a robust management practice and a candidate selection trait for enhanced reproductive performance in drylands. animal, 18 (11). |
| spellingShingle | fertility ram effect heritability barbarine sheep sheep genetic trend Ben Salem, Imene Rouatbi, Mariem Mlika, Mariem Getachew, Tesfaye Govind, Ajit Haile, Aynalem Raggem, Mohamed Lahsoumi, Ridha Rekik, Mourad Response of maiden ewes to the ‘ram effect’ is a robust management practice and a candidate selection trait for enhanced reproductive performance in drylands |
| title | Response of maiden ewes to the ‘ram effect’ is a robust management practice and a candidate selection trait for enhanced reproductive performance in drylands |
| title_full | Response of maiden ewes to the ‘ram effect’ is a robust management practice and a candidate selection trait for enhanced reproductive performance in drylands |
| title_fullStr | Response of maiden ewes to the ‘ram effect’ is a robust management practice and a candidate selection trait for enhanced reproductive performance in drylands |
| title_full_unstemmed | Response of maiden ewes to the ‘ram effect’ is a robust management practice and a candidate selection trait for enhanced reproductive performance in drylands |
| title_short | Response of maiden ewes to the ‘ram effect’ is a robust management practice and a candidate selection trait for enhanced reproductive performance in drylands |
| title_sort | response of maiden ewes to the ram effect is a robust management practice and a candidate selection trait for enhanced reproductive performance in drylands |
| topic | fertility ram effect heritability barbarine sheep sheep genetic trend |
| url | https://hdl.handle.net/10568/159635 |
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