Effect of semen extenders and storage time on quality of Muscovy duck (Cairina moschata) drake semen during the entire reproductive season

Improvement of diluted semen from Muscovy (Cairina moschata) drakes by the addition of water-soluble antioxidants

The aim of this study was to evaluate the effect of antioxidant supplementation in diluted semen from Muscovy drakes after the induction of oxidative stress (OS) on the sperm motility, kinematic parameters and biochemical markers - lipid peroxidation (LPO) levels and total glutathione (tGSH) concentration. The pooled semen was distributed equally into three parts, diluted (1:3 v/v) with IMV Canadyl, HIA-1 or AU, and stored at 4°C for 6 h. Later, the semen was equilibrated at 20-25°C for 15 min, and divided in Eppendorf tubes. The sperm samples (final concentration of 50 × 106 sperm cells/mL per sample) were incubated at 37°C for 30 min in the absence (-) or presence (+) of 0.1 mM FeSO4  + 0.5 mM H2 O2 (Fenton system) and the following combinations of antioxidants: ascorbic acid + Trolox (A + T); ascorbic acid + Desferal (A + D); Trolox + Desferal (T + D) and ascorbic acid + Trolox + Desferal (A + T + D), all of them in a final concentration of 0.1 mM. Thus, the total number of samples was 30 and in each one, the sperm motility, velocity parameters, LPO and tGSH were determined. The motility and kinematic parameters of the diluted semen with added antioxidants were restored by up to 20% after inducing OS via the Fenton reaction. Dual combinations of antioxidants (A + T, A + D, and T + D) lowered LPO levels, but not equally across different extenders. After the induction of OS, the tGSH levels in diluted semen with IMV-Canadyl were not affected by the added antioxidants. Whereas antioxidant combinations in diluted semen with HIA-1 or AU had a beneficial effect and partially restored tGSH levels. In conclusion, the results showed that the extender IMV-Canadyl is well balanced and protected the Muscovy semen under OS conditions, while the other two extenders HIA-1 and AU can be improved by adding antioxidants.

Machine Learning Approach for Muscovy Duck (Cairina moschata) Semen Quality Assessment

This study aimed to develop a comprehensive approach for assessing fresh ejaculate from Muscovy duck (Cairina moschata) drakes to fulfil the requirements of artificial insemination in farm practices. The approach combines sperm kinetics (CASA) with non-kinetic parameters, such as vitality, enzyme activities (alkaline phosphatase (AP), creatine kinase (CK), lactate dehydrogenase (LDH), and γ-glutamyl-transferase (GGT)), and total DNA methylation as training features for a set of machine learning (ML) models designed to enhance the predictive capacity of sperm parameters. Samples were classified based on their progressive motility and DNA methylation features, exhibiting significant differences in total and progressive motility, curvilinear velocity (VCL), velocity of the average path (VAP), linear velocity (VSL), amplitude of lateral head displacement (ALH), beat-cross frequency (BCF), and live normal sperm cells in favour of fast motility ones. Additionally, there were significant differences in enzyme activities for AP and CK, with correlations to LDH and GGT levels. Although motility showed no correlation with total DNA methylation, ALH, wobble of the curvilinear trajectory (WOB), and VCL were significantly different in the newly introduced classification for "suggested good quality", where both motility and methylation were high. The performance differences observed while training various ML classifiers using different feature subsets highlight the importance of DNA methylation for achieving more accurate sample quality classification, even though there is no correlation between motility and DNA methylation. The parameters ALH, VCL, triton extracted LDH, and VAP were top-ranking for "suggested good quality" predictions by the neural network and gradient boosting models. In conclusion, integrating non-kinetic parameters into machine-learning-based sample classification offers a promising approach for selecting kinetically and morphologically superior duck sperm samples that might otherwise be hindered by a predominance of lowly methylated cells.

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%).

Spermatozoa Survival in Egg Yolk-Based and Soybean-Based Extenders at Ambient and Chilling Temperature in Domestic Turkeys (Meleagris gallopavo)

Populations of many galliform species have declined mainly due to habitat loss and over-hunting, notably the Congo peacock, which has been classified as a vulnerable species by the International Union for Conservation of Nature (IUCN). The domestic turkey, being a species of least concern, which has been reported to be closely related to peacocks, could serve as a model for the optimization of assisted reproductive technologies for the Congo peacock. This study was aimed at developing a suitable turkey semen extender for artificial insemination in field conditions. Semen was collected using the dorso-abdominal massage technique from seven turkey toms and analyzed. Ejaculates with >70% motility and >80% live spermatozoa were pooled and divided into four aliquots (four treatments). Each of the four treatments was extended in a soybean-based extender or an egg yolk-based extender, with or without L-ascorbic acid. Two liquid preservation protocols (ambient temperature (35 °C) and chilled (4 °C)) were employed, and quality parameters including motility, viability and morphology were evaluated. The results show that the two extenders were similar with regard to semen quality parameters, and L-ascorbic acid supplementation of the turkey semen extenders improved semen quality during liquid 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.

Reproductive season and male effect on quantitative and qualitative traits of individually collected Muscovy duck (Cairina moschata) semen

Males of Muscovy duck (Cairina moschata) are mainly used for mule duck production via artificial insemination of females originated from wild mallard duck (Anas platyrhynchos); therefore, the quantity and quality of drake semen play a crucial role. The assessment results of male reaction to sexual stimulation by dummy female and basic semen characteristic (ejaculate volume, sperm concentration and morphology) of 12 individually kept Muscovy drakes carried out during the entire reproductive season are described. The male and period of the reproductive season effect on scored semen traits are documented. In total, 792 individual semen collections and evaluations were performed. The average of positive reaction in the entire reproductive season varied from 90.6% in December and April to 50.0% in July, while for individual males, it varied between 97.1% and 29.0%. Throughout the season, the ejaculate volumes ranged from 0.05 to 2.45 ml, sperm concentration from 0.15 × 10⁹ ml^-1 to 4.44 × 10⁹ ml^-1 , total number of live spermatozoa from 68.0% to 100% and live normal (properly formed, with any deformations) from 51.0% to 99.0%. Our study indicates the necessity of male breeders pre-selection before the onset of the reproductive season, and the need to leave an appropriate number of males to ensure adequate amount of semen for female insemination, especially when using Muscovy drakes (Cairina moschata) for interspecies crossing with Anas platyrhynchos ducks.