Hormonal treatments used in the artificial insemination (AI) of sheep can cause several physiological problems that can affect negatively fertility and animal health; however, AI protocols based on the detection of natural estrus offer a more sustainable option and can achieve high fertility. In this study, an AI protocol at natural estrus in organic sheep was performed. In the first phase (AI protocol development), 125 ewes were exocervically inseminated, and their fertility was assessed based on the following factors: number of AI, physiological state, body condition, estrus detection-AI interval, and vaginal fluids in cervix. That protocol was repeated for six consecutive years. In all individuals, fertilities based on the timing of insemination after estrus detection were very high. Lactating ewes produced better results than did dry ewes, which was probably because of the better feeding of the former. In addition, double insemination increased the fertility of ewes whose estrus was detected within 16 h of onset. Body condition and amount of vaginal fluid were correlated with fertility. Exocervical inseminations at natural estrus can produce acceptable fertility and prolificity in Churra ewes.
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http://dx.doi.org/10.3390/vetsci9070370 | DOI Listing |
CRISPR J
January 2025
Department of Animal Science, University of California, Davis, California, USA.
In mice, naturally occurring and induced mutations in the suppressor of cytokine signaling-2 () gene are associated with a high growth phenotype characterized by rapid post-weaning weight gain and 30-50% heavier mature body weight. In this work, we demonstrate an electroporation-based method of producing knock-out (KO) sheep. Electroporation of dual-guide CRISPR-Cas9 ribonucleoprotein complexes targeting was performed 6 h post-fertilization in sheep zygotes.
View Article and Find Full Text PDFAnimals (Basel)
December 2024
State Key Laboratory of Animal Biotech Breeding, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
The photoperiod has been considered to be a key environmental factor in sheep reproduction, and some studies have shown that the thyroid gland plays an important role in mammalian reproduction, but the molecular mechanism is still unclear. In this study, we used the artificial-light-controlled, ovariectomized, and estradiol-treated model (OVX + E2 model); healthy and consistent 2-3-year-old Sunite multiparous ewes were collected; and thyroids were collected for testing, combined with RNA-seq technology and bioinformatics analysis, to analyze the effects of different photoperiods (long photoperiod treatment for 42 days, LP42; short photoperiod treatment for 42 days, SP42; SP42 transferred to LP42, SPLP42) on the variations in the miRNA profiles of the thyroid gland. A total of 105 miRNAs were differentially expressed in the thyroid gland, most of which were new miRNAs.
View Article and Find Full Text PDFSci Rep
January 2025
Centre for Ecology and Conservation, Faculty of Environment, Science & Economy, University of Exeter, Penryn Campus, Cornwall, TR10 9FE, UK.
Promiscuous females reduce male reproductive control. Males can attempt to monopolise access to these females, but distractions and sneaky rivals mean extra copulations cannot always be blocked. By mating first, males can obtain a headstart in sperm competition, but this may be negated by sperm storage and cryptic female choice mechanisms.
View Article and Find Full Text PDFZoo Biol
January 2025
Taronga Conservation Society Australia, Taronga Institute of Science and Learning, Mosman New South Wales 2088, Taronga Western Plains Zoo, Dubbo, New South Wales, Australia.
A zoo-based, 11-year-old, uniparous southern black rhinoceros (Diceros bicornis minor) failed to conceive after weaning a calf. Behavioral observation and fecal progestagen monitoring confirmed irregular estrous cycles. Serial transrectal reproductive ultrasound examination revealed the cause to be recurrent anovulatory hemorrhagic follicles (AHFs).
View Article and Find Full Text PDFMicroorganisms
December 2024
Sichuan Key Laboratory of Conservation Biology for Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, Chengdu 610081, China.
The poor reproductive capacity of giant pandas significantly hinders the development of captive populations, with 80.88% of adult individuals being unable to successfully become pregnant and deliver offspring. The disturbance of vaginal microbiota has been proven to potentially lead to miscarriage, abortion, and stillbirth in mammals.
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