Antioxidant enrichment of rooster semen extenders - A systematic review.

The purpose of this systematic review was to evaluate the potential benefits of antioxidant enrichment of semen extenders. These substances are used to combat oxidative stress during processing and conservation of rooster semen. A literature search was performed in June 2020 using the keywords rooster AND (semen OR spermatozoa OR sperm OR ejaculate OR ejaculation). This report followed the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) guidelines. The PICO (population intervention comparison outcome) question was defined to compare roosters (Population) which had added antioxidants in the semen (Intervention) compared to the no-antioxidant group (Control); the outcome was semen quality (Outcome). Only articles investigating rooster cooled or frozen enriched semen with antioxidant extenders (Gallus Gallus domesticus) were selected by reading the title and abstract, totalizing 38 articles. After full text reading, we found that only 13 studies carried out sperm characteristics and fertility assays. To assess article quality, 15 items related to rooster breeding conditions, seminal collection methodology, and analyzed variables (seminal characteristics and fertility test) were established. There were positive effects of antioxidants on the preservation of seminal characteristics (motility, viability, membrane integrity, antioxidant activity, and lipid peroxidation) and on semen fertility after the conservation process. We conclude that the antioxidants reduce the oxidative stress and improve fertilizing capacity. The most used substances for cooled semen are glutathione, CoQ10, and l-carnitine; whereas for frozen semen, resveratrol, lycopene, and quercitin are most frequently used.

Vulvar width and rima length as predictors of the ovarian follicular reserve in bovine females.

The aim of this study was to investigate possible relationships between morphometric characteristics of the bovine reproductive tract and measures of fertility, such as antral follicle counts (AFCs) and the number and quality of recovered cumulus oophorus complexes (COCs). First, the genital tracts of 360 abattoir Zebu/Holstein crossbred cows were studied. Rima vulvae length (RL), vulvar width (VW), ovarian size, pelvic fat, number of aspirated COCs, and AFCs were recorded. An index of COC quality (CQI) was established, which weighed overall gamete quality based on the IETS classification. Second, the same external measurements and AFCs (by ultrasound) were analyzed in live Tabapuã (Zebu) cows (n = 48). Relative RL and vulvar width were defined as the original measurements divided by the body weight of each cow for statistical analyses. In abattoir tracts, the AFC was smaller (P < 0.05) in animals with large VW (34.88 ± 3.50) than in animals with small (45.71 ± 2.57) and intermediate (42.25 ± 2.45) VW. The CQI was higher (P < 0.05) when the pelvic fat score was intermediate (3.22 ± 0.06) than that in lean (2.99 ± 0.08) and obese (2.90 ± 0.12) animals. The CQI was higher (P < 0.05) in the intermediate ovary group (3.19 ± 0.08) than in the small (2.96 ± 0.08) and large (2.95 ± 0.09) ovary groups. In live cows, the AFC was higher (P = 0.035) in females with large relative rima length than in those with small relative rima length (18.96 ± 1.97 and 14.76 ± 1.51, respectively). Similarly, AFC was greater (P = 0.0001) in females with large relative VW than in those with small relative VW (20.08 ± 1.36 and 11.16 ± 1.60, respectively). In conclusion, larger external genitalia relative to body size were good predictors of the ovarian follicular reserve in live animals.