Seasonal variation of semen quality among the three genotypes of native chicken

The study, conducted at the Bangladesh Livestock Research Institute, aimed to assess semen quality and characteristics in three types of indigenous cocks and explore seasonal variations. Ninety bird samples from three genotypes, namely non-descript Deshi (ND), Hilly (HI), and Naked Neck (NN), were used in this research. A total of 548 semen samples were collected to evaluate the color, volume, consistency, and transparency of semen in different seasons. Semen collection was performed using an abdominal massage technique, and volume was measured with a tuberculin syringe. For determining microscopic physical and morphological characteristics, computer-assisted sperm analysis (CASA) software was used. Results showed that among three types of indigenous cocks, semen quality differed (p < 0.001) from season to season. Semen quality was comparatively good for ND in the autumn season, for HI in the summer season, and for NN in the spring season. The highest semen volume (0.318 ± 0.010 ml) was recorded in the summer season, and the lowest semen volume (0.218 ± 0.008 ml) was recorded in the spring season. Genotype had a significant (p < 0.01) effect on semen volume, and the effect of semen and genotype interaction on semen volume was non-significant (p > 0.05). The sperm concentration was higher in NN compared to ND and HI. The percentages of static, bent tail, coiled tail, DMR, distal droplet, and proximal droplet were comparatively higher in the HI and NN genotypes. The color, consistency, and volume of semen were affected by genotype and season.


Introduction
Poultry semen is a vital resource in the poultry business since it contributes to the creation of healthy and productive bird populations by helping to preserve and improve the desired features of various chicken breeds.Poultry semen can be used for various purposes, such as artificial insemination (AI) in poultry breeding programs (Tarif et al., 2013;Ali et al., 2021).Artificial insemination allows for selective breeding and genetic improvement by controlling which male genetics are used to fertilize the eggs.It enables breeders to choose specific traits, such as improved growth rate, disease resistance, or egg production, and pass them on to the next generation more efficiently.Semen collection is a common practice for artificial insemination (AI) (Paul et al., 2017;Ali & Islam, 2021).For artificial insemination technology, semen collection, semen quality evaluation, semen ejaculation, and seasonal semen characteristics are known to be important.Semen quality plays a major role in AI (Bakst & Dymond, 2013).Semen quality must be assessed before being utilized for AI in chickens, just as it is in other livestock species.Seasonal differences in poultry semen quality may vary by geographical area (Wannaratana et al., 2021).Bangladesh has a subtropical monsoon climate with large seasonal rainfall changes, generally mild temperatures, and high humidity.The meteorological seasons are known as spring (March-May), summer (June-August), autumn (September-November), and winter (December, January, and February).Commonly, premonsoon months are hot and humid; monsoon months are humid and rainy; post-monsoon months are quite hot and dry; but the winter months are cool and dry (Khatun et al., 2016).The introduction of artificial insemination (AI) technology in poultry production has allowed for the rapid spread of genetic material from a small number of superior males to a large number of females.To achieve maximum fertility in chickens, this procedure requires high-quality semen that is inseminated extremely close to the semen storage tubules in the female.Semen quality evaluation provides an indication of male reproductive capacity and is a primary factor in fertility and, consequently, egg hatchability.However, for successful AI in the field, a visual evaluation of the semen is required.A clean semen sample of sufficient volume is required on a regular basis to properly perform AI (Mohan et al., 2018).Lack of knowledge of the high volume of semen acquired from specific indigenous cocks makes it very difficult to achieve a good result from artificial insemination.If semen volume is high and quality is good, it is helpful for cryopreservation and application during breeding season.By determining semen characteristics, it is possible to know which type of semen is best for artificial insemination in three native cocks for maximum fertility (Rahman et al., 2018;Ali, 2020).The purpose of this study is to inform the people associated with poultry about semen quality characteristics, seasonal variation of poultry semen quality, and the physical and morphological characteristics of semen.Good quality of semen is important for storing semen, the number of sperm in the semen, and performing for not only egg production but also hatchability of eggs.The aim of the study is to determine if there is any seasonal variation in semen quality among three types of native cocks.The laboratory-based experiment aims to find out the motility rate of the semen of indigenous cocks due to climatic conditions.With a view to knowing the seasonal effect and seasonal variation of semen quality and quantity, the objectives of this study were to evaluate the semen characteristics of three types of indigenous cocks and find out the seasonal variation.

Materials and methods
The present study was conducted with native chickens in Bangladesh.This study used three types of native chickens (Non-Descript Deshi, hilly, and Naked Neck).The research is based on data collected from a total of 90 selected male birds (30 birds from each genotype) and duration from March 2021 to November 2021 in three seasons (spring, summer, and autumn).

Poultry rearing system
Poultry birds were kept in an open sided semi-gable roof with a concrete floor poultry house.Throughout the experiment, all males were exposed to sixteen hours of light every day under normal environmental circumstances.Individual cages were used to raise the chosen birds.Each cage was outfitted with its own feeder and drinker.All of the birds were raised in a poultry house with natural ventilation.Maize, rice polish, soyabean meal, protein concentrates, and synthetic methionine and lysine were utilized to prepare feed for these selected birds.As well as minerals, calcium phosphate, vitamin were mixed with feed.Same feed preparing procedure was followed from Faruque et al. (2020).

Semen collection technique
A semen collection experiment was conducted on poultry birds kept in individual cages.Throughout the trial, the birds were grown in a natural setting with natural light and a dark photoperiod.Semen samples were collected by the abdominal massage technique according to the procedure described by Abutu (2015).

Macroscopic examination of semen
Visual inspection was used to determine the color, consistency, and transparency in a macroscopic way.The properties of semen were determined immediately after collection.The color of semen is divided into two types: creamy white and milky white.In consistency determination, some criteria were followed, like "thicky", meaning that after the collection of semen in a cup, if semen movement is slow, it is considered "thick".If the movement of semen in the cup is quick, it is watery.To know the transparency of semen, it is divided into three categories: opaque, clear, and cloudy.The volume of semen was measured from the semen collecting tube after collection in mL Semen microscopic examination Immediately after semen collection and taken in a tube.Semen (40µl) was mixed with DMEM solution media (3.8 ml).The ratio of the solution mixture was 1:100, and it was then put into a 20-micron standard count 4 chamber slide and input into the analyzer.By using the CASA (computer-assisted semen analysis) software semen analysis system (Hamilton Throne Ivos), The semen was examined for morphological features like motility (static, progressive, motile, slow), sperm concentration, tail abnormalities like bent tail, coiled tail, and head abnormalities (DMR, distal droplet, proximal droplet, etc.).Motility was calculated as the percentage of motile sperm with moderate to rapid progressive movement.

Temperature-humidity index (THI)
Temperature and humidity data were recorded to determine if there was any influence of body metabolism activity on chicken and semen characteristics.Average temperature (°C) and average humidity (%) data were recorded from March 2021 to November 2021.The temperature-humidity index (THI) was calculated using a mathematical model (Sonseeda et al., 2013), The formula is THI: (0.8×AT) + [(RH/100) ×(AT-14.4)]+ 46.4,where AT is ambient temperature (°C) and RH is relative humidity (%).

Statistical analysis
The characteristics of the semen of three different genotypes were analyzed by Microsoft Excel, and the semen volume was subjected to the analysis of variance (ANOVA).The physical characteristics of semen data were analyzed based on two fixed independent variables, namely the genotype and season of indigenous chickens in Bangladesh.Hence, it fulfilled the characteristics of a non-orthogonal factorial experiment and was analyzed by the Generalized Linear Model (GLM) Procedure using SPSS 20.0 for Windows (SPSS, 2012).For seasonal and genotype variation of semen, the following model was used: Yijk = µ+Gi+Sj+(G×S) ij+eijk Yijk = Dependent variables (semen volume, motility, sperm concentrations etc.) µ = overall mean Gi = Effect of ith Genotype (i = 3) Sj = Effect of jth season (j = 3) (G×S) ij = Interaction effect of ith Genotype and jth season eijk = Random residual error associated with Yijk observation.

Effect on semen color
The percentage of semen color is presented in Figure 1.In this experiment, the creamy white color is 61.36 % for Naked Neck (NN), 50.53 % for Hilly (HI), and 41.25 % for Non-descript Deshi (ND) in the spring season.But the color of semen differed in the summer season.In the summer season, the semen color of creamy white is 45.0% for nondescript Deshi, 68.0 % for Hilly, and 50.0 % for Naked Neck.In the autumn season, the color of creamy white is 54.54 % for NN, 53.33 % for HI, and 48.33 % for ND.From these findings, it can be concluded that the color of semen is best for Hilly in the summer season.In the autumn season, the percentage of creamy white color difference between Hilly and Naked Neck is low.In this study, the result showed that the percentage of the color of semen among ND, HI, and NN varies from season to season and genotype to genotype.The percentage of milky white color is comparatively higher for ND in spring, summer, and autumn compared to other genotypes.For HI, the percentage of milky white color was 49.46 % in spring, 32.0 % in summer, and 46.66 % in the autumn season.In the case of NN, the color of milky white and creamy white in the summer season was similar (50.0 %), and a dissimilar result was found in the autumn and spring seasons.

Effect on semen consistency
The result showed that for all types of indigenous cocks, the thick condition of semen was always higher than watery (Figure 2).In this study, for ND, the thicky semen in the spring, summer, and autumn seasons was 62.24 %, 62.50 %, and 61.66 %, respectively (Figure 2).The study showed that in the summer season, the consistency of thick semen was good for ND and HI.In the summer season, the thick condition of semen was 76.0 % for HI.The highest percentage of thicky condition (65.45 %) was found in NN compared to other genotypes in the autumn season.
Temperature and humidity record Summer had the highest average humidity, while spring had the highest temperature compared to the other seasons described in Table 1.In the summer season, the highest average temperature was 35.55 °C and the average humidity was recorded at 84.17 %, which could have resulted in heat stress in the experimental bird.In the summer season, the temperature-humidity index is high (87.11%).

Effect of season and genotype on semen volume
Semen volume was significantly affected by season (p < 0.001) and genotype (p < 0.01) (Table 2).The highest semen volume in the summer season was found at 0.318 ± 0.010 ml, and the lowest semen volume was recorded in the spring season at 0.218 ± 0.008 ml.This could be related to variations in ambient temperature across seasons.In addition, genetic differences in semen volume were observed in the current study.In ND, the volume of semen was observed at 0.292 ± 0.010 ml, in HI at 0.297 ± 0.010 ml, and in NN at 0.297 ± 0.011 ml, respectively (Table 2).This difference could be attributed to seasonal differences or, more likely, to differences in the genetic backgrounds of the indigenous cocks.Genotype had a significant difference (p < 0.01) on semen volume.Semen volume was not affected (p > 0.05) by the season × genotype interaction.

Discussion
The color of semen (creamy white) in the summer season indicates that Hilly is comparatively better than other native cocks.For the collection of semen in thick conditions, summer is the best for the HI genotype, as is autumn, which is the best for the Naked Neck.The results showed that summer is the best season for the collection of semen from all genotypes regarding volume of semen (0.318 ± 0.01 ml).The physical characteristics of semen (color, consistency, and volume) differ due to seasonal effects.But environmental influences have little effect on semen (Sonseeda et al., 2013;Bhuiyan et al., 2019).Adamu et al. (2019) reported that the color of sperm does not differ significantly between the early dry season, late dry season, and early rainy season, but that all of these seasons were much more intense in color intensity than the late rainy season.
In this experiment, the volume of semen in different seasons was highly significant.In this study, semen volume differed significantly across seasons and genotypes.The findings of Adamu et al. (2019) showed a similar result in the case of semen volume.Ameen et al. (2014) studied poultry semen in Nigeria and showed the same result.
There is no effect of genotypes on the sperm concentration of semen, but other parameters like the percentage of static, progressive, motile, coiled tail, and distal droplets are statistically significant.Ameen et al. (2014) observed no significant difference in sperm abnormalities and motility; however, sperm abnormalities (coiled tail, distal droplet) and motility were significant in this experiment.Tarif et al. (2013) studied three different varieties of cocks and found that sperm concentration changed among the varieties.This result is not similar to the experiment, Hambu et al. (2016) conducted research on three Indonesian cocks and found that sperm motility and live sperm were non-significant, but sperm concentration was significant.This is contrary to this experiment.Al-Darazi et al. (2001) studied the quality of cocks' sperm and found that sperm concentration, motility, and living and dead sperm differed depending on the season.
However, it is very clear that average ambient temperature, average relative humidity, and season significantly affect semen volume in three types of native chicken.It was found that THI and season had an effect on sperm concentration, motility percentage, and progressive motility but had a low effect on semen color, consistency, and transparency (Ali et al., 2020).It is very important to know the quality of semen, the seasonal variation for artificial insemination, and the hatchability of eggs.

Conclusions
The findings of this research showed that semen quality characteristics (color, consistency) differed from season to season, and semen volume was affected by season and also varied from genotype to genotype.According to this study, the best time to collect semen for artificial insemination is during the summer months.The research might be beneficial for poultry breeders in selecting native cocks for poultry breeding and artificial insemination throughout the different seasons of the year.

Figure 1 .
Figure 1.The percentage of color of semen in different seasons of the three native chickens

Figure 2 .
Figure 2. The percentage of thicky and watery condition of semen in different seasons of the three native chickens

Table 1
Temperature-humidity index (THI) of poultry rearing house

Table 2
Least squares Means (±SE) of semen volume as affected by season and genotype

Table 3
Physical and morphological parameters of semen of three native chicken cocks = means that the letters in same row are significantly different.p < 0.01 means highly significant, NS means non-significant.Values are (mean ± SE).