Effect of semen extenders on viability of ISA Brown and Hubbard Flex roosters' sperm stored for 24 h

Effect of freeze-dried quail egg white and yolk addition to semen extender on viability of rooster sperm stored for 6 h at 4°C

The effect of freeze-dried quail egg white and yolk addition to basic EK extender on morphology and motility of chicken broiler breeder semen was investigated. Fresh pooled semen was divided into eight parts: fresh, undiluted (control), diluted in 1:2 ratio (v/v) with basic EK extender, EK + 200 mg/ml of egg white, EK + 100 mg/ml of egg white, EK + 50 mg/ml of egg white, EK + 100 mg/ml of egg yolk, EK + 50 mg/ml of egg yolk, EK + 25 mg/ml of egg yolk. Semen samples were evaluated 15 min after dilution and after 6 h of storage at 4°C. In the fresh semen, the number of live normal sperm was the highest in semen diluted with EK + 200 mg of egg white and EK + 100 mg of egg yolk, while the highest sperm motility was in the neat semen. Semen storage reduced the number of normal sperm in all analysed semen samples. In the neat semen, the number of normal sperm decreased, in relation to the fresh not-stored samples, by 36.8% (from 72.3% to 35.5%), with EK extender by 9.2%, in samples enriched with egg white, from 8.4% (EK + 200 mg) to 10.0% (EK + 100 mg), and in EK with egg yolk addition, from 1.2% (EK + 50 mg) to 10.6% (EK + 100 mg). The highest percentage of motile sperm was observed in EK extender enriched with 50 mg of egg white (77.1%) and EK + 25 mg of egg yolk (65.3%).

Mitochondria-targeted antioxidant "MitoQ" improves rooster's cooled sperm quality indicators and reproductive performance

The cell membrane of rooster sperm is sensitive to cold due to the high content of polyunsaturated fatty acids, which are very susceptible to lipid peroxidation. The present study was conducted to determine the effect of different concentrations of the mitochondrial-targeting antioxidant "MitoQ" on sperm quality and fertility potential of chilled semen in roosters. Semen samples were collected from 10 roosters, diluted in Lake extender, assigned into 5 groups according to MitoQ concentrations (0, 1, 10, 100 and 1000 nM MitoQ) and stored at 5 ^°C up to 48 h. Motility, mitochondrial activity, viability, membrane integrity, and lipid peroxidation were assessed at 0, 24, and 48 h of cold storage periods. In addition, the fertility potential was assessed using 24 h-cooled semen samples. Our results showed that extender supplementation with MitoQ had no effect (P > 0.05) on chilled semen samples quality parameters at time 0, while at times 24 and 48 h storage, samples contained 100 nM MitoQ presented higher (P ≤ 0.05) total motility, progressive motility, viability and membrane integrity compared to the other groups. In addition, semen samples containing 10 and 100 nM MitoQ showed higher (P ≤ 0.05) mitochondrial activity and lower (P ≤ 0.05) lipid peroxidation than other groups at 24 and 48 h storage. Fertility rate was higher (P ≤ 0.05) when the hens were artificially inseminated with 24 h-chilled semen samples containing 100 nM MitoQ. In conclusion, supplementing Lake Extender with 100 nM MitoQ could be a helpful strategy to preserve chilled semen quality and fertility potential in the rooster.

Assessing different liquid-storage temperatures for rooster spermatozoa

Although liquid-storage is extensively used in poultry, there are still questions on how sperm physiology is affected and to what extent sperm functions are disrupted by storage temperature and time. There, therefore, was investigation of storage temperature and durations on multiple semen variables. The storage at 37 °C was the most damaging, affecting values for several variables within 4 h of storage, whereas most differences occurred between 5 and 25 °C after 8 h. Progressive motility and mitochondrial function started to decrease within 2 h at 25 and 37 °C, and within 4 h at 5 °C. Acrosomal damage only occurred in samples at 37 °C. Eosin-negrosin staining indicated there was damage to the plasma membrane at 37 °C, however, with use of propidium iodide there were differences between 5 and 25 °C following 24 h. Temperatures of 5 and 25 °C resulted in similar curves for chromatin dispersion although chromatin integrities differed with storage for periods longer than 4 h. At 37 °C, results using both chromatin evaluations indicated there was damage after 2 h of incubation. Oxidative stress at 5 and 25 °C was similar when there was 24 h of storage. Intriguingly, there were no interaction between temperature and storage duration for peroxidized sperm membrane and total peroxidation status. These findings indicated that with a prolonged storage at 5 °C there were not marked changes in chicken spermatozoa, whereas at 25 °C there did not appear to be sperm damage occurring as a result of short-term storage.

Characteristics of semen collected from gander included in the genetic resources conservation program

Conservative breeding ex situ in vivo is one of the most popular methods of creating genetic reserves. Unfortunately, keeping animals in small closed populations leads to inbreeding which reduces their reproductive capacity. The aim of the study was to characterize the sperm quality of 6 genetic groups of geese (northern and southern breeds) kept in Poland for many generations as genetic reserve flocks. Each breed was represented by 10 randomly selected 1-yr-old ganders, semen was collected 14 times, individually from each male, and the number of positive reactions (ended with ejaculation), semen volume, sperm concentration, and morphology were assessed. The obtained results showed a significant difference between breeds and individuals of the same group, both in males’ reaction and semen quantitative and qualitative traits. From the northern breeds 193 ejaculates were obtained in total (i.e., 45.9% of all attempts), from the southern breeds 242 ejaculates (57.6%). The volume of single ejaculate varied from 0.01 mL (one drop allowing only histological smear and sperm morphology evaluation) to 0.65 mL; sperm concentration varied from 23.0 × 10⁶mL⁻¹ to 2376.0 × 10⁶mL⁻¹; the amount of total live sperm was at a similar level in all breeds (89.6%–97.7%), while live normal cells ranged between 15.2% and 67.9% depending on breed and individuals. When keeping the genetic reserves ex situ in vivo, attention should be paid to the quality of semen and males that are poor in this respect should be eliminated, in order not to lead to an excessive weakening of the reproductive capacity of the flocks covered by the genetic resources protection program.

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.