Dietary supplementation with flaxseed oil as source of Omega-3 fatty acids improves seminal quality and reproductive performance in aged broiler breeder roosters

Dietary alpha-linolenic acid supplementation enhances semen quality, antioxidant capacity, and sperm survival in aging breeder roosters

Aging in breeder roosters is often accompanied by a decline in semen quality, negatively impacting reproductive performance. This study aimed to investigate the effect of dietary alpha-linolenic acid (ALA), an essential omega-3 polyunsaturated fatty acid, on semen quality, antioxidant capacity, and sperm survival in aging breeder roosters. Roosters were divided into 4 groups and fed diets supplemented with 0%, 0.5%, 1%, and 2% ALA for 6 wk. Results indicated significant improvements in semen volume, sperm viability, and sperm density in ALA-supplemented groups compared to the control (P < 0.05). The 1% ALA group exhibited the most notable enhancements in sperm viability and density. Additionally, ALA supplementation increased the activities of antioxidant enzymes such as superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and reduced malondialdehyde (MDA) levels, indicating enhanced antioxidant capacity (P < 0.05). Furthermore, ALA improved mitochondrial membrane potential (MMP) and reduced early and late sperm apoptosis, with the 2% ALA group showing the highest MMP and the lowest ROS-positive rate (P < 0.05). These findings suggest that dietary ALA supplementation enhances semen quality and antioxidant defenses, and mitigates oxidative stress, thus supporting the reproductive health of aging breeder roosters. This study underscores the potential of ALA as a dietary strategy to improve reproductive efficiency in poultry production.

Recent strategies to mitigate reproductive aging in male broiler breeders: A review

The continued improvement of genetics, nutrition, and management has resulted in rapid growth, better feed efficiency, and higher meat yield with competitive prices in the broiler industry. Nowadays, however, it is well-documented that productive traits and fertility are negatively correlated, and male broiler breeders are exposed to a fertility decline after 45 wk of age. Considering a low male-to-female ratio in breeder flocks, roosters have a prominent impact on flock fertility. Consequently, strategies to maintain the fertility of male broiler breeders could guarantee the reproductive performance of commercial herds. Understanding reproductive aging demands deep insights into its molecular and physiological mechanisms. Over-weighting, Sertoli and Leydig cell dysfunctions, compromised antioxidant capacity, imbalance in sexual hormones, and epididymal lithiasis are among candidate culprits associated with reproductive aging in roosters. Nutritional and managing strategies have been successfully applied to modulate body weight, improve sperm fatty acid profile and antioxidant status, and boost spermatogenic and steroidogenic pathways. The current review characterizes the physiology and biochemistry of reproductive aging in male broiler breeders and then highlights strategies and their underlying mechanisms to mitigate this failure. In summary, applying one or more of the abovementioned strategies might result in consistent post-peak reproduction and benefit producers in the poultry industry.

Dietary supplementing South African indigenous rams with flaxseed oil and ascorbic acid improves cryopreserved semen quality and in vitro fertility

The purpose of this study was to evaluate how ascorbic acid with dietary flaxseed oil affects the quality and fertility of cryopreserved ram sperm in South African indigenous rams. Treatment diets were supplemented 60 days before semen collection to afford proper spermatogenesis, adaptation to the feed formulated and fed throughout the study. Semen was collected with the use of artificial vagina following dietary supplementation with five treatment diets (neg. cont. - negative control, pos. cont. - positive control, FLO - 5% Flaxseed oil, ASA - 4% Ascorbic acid, and FLO + ASA). Semen was then extended using tris-based extender and cryopreserved using the programmable freezer (CBS Freezer 2100 series, Laboratory consumables & chemical suppliers, America). Ovaries were collected from a neighbouring slaughter house and conveyed to the lab in 0.9% saline at 37 °C. Data (sperm parameters and in vitro fertility) was then exposed to the GLM (General Linear Model) in Minitab 17. Pearson's correlation coefficient was utilized to investigate the relationship between cryopreserved sperm quality and in vitro fertility. The student Least Significant Difference Test was used to separate the treatment means, and differences were accepted when the p-value was less than 0.05. The FLO + ASA group had higher (p < 0.05) progressive (36.33 ± 1.87), total (88.24 ± 2.24), rapid motility (27.52 ± 1.74), intact plasma membrane (75.67 ± 2.08), total fertilization (65.98 ± 7.39), and total cleavage (66.19 ± 6.50) when compared to other treatment groups. Total fertilization rate had a medium significant (p < 0.001) medium correlation with the progressive motility (r2 = 0.435), total motility (r2 = 0.447) and rapid motility (r2 = 0.409). In conclusion, dietary flaxseed and ascorbic acid (FLO + ASA) improves cryopreserved semen quality, in vitro fertilization rate, and the total cleavage rate. Noteworthy, the progressive, total and rapid motility play a crucial in the in vitro fertilization rate.

Effect of olive, flaxseed, and grape seed nano-emulsion essential oils on semen buffalo freezability

The existing treatise targeted to compare the effects of adding different nano-emulsions essential oils (olive, flaxseed, and grapeseed oils) in freezing extender on semen quality and freezability in buffalo. Nano-emulsions were prepared from olive, flaxseed, and grapeseed oils and characterized for their sizes and shapes. Semen extended in four tubes were supplemented with 0 (control) and 3.5% nanoemulsion oils, including olive (NEO), flaxseed (NEFO) and grape seed oils (NEGSO) respectively. NEGSO resulted in the highest (p < 0.05) membrane integrity, vitality, progressive motility (P-motility) of sperm compared to the other groups in post-thawed buffalo bull semen (at 37 °C for 30 s). The addition of NEGSO had the best results for membrane integrity, progressive motility, and vitality of sperm after incubation (at 37 °C and 5% CO2 for 2 h). A superior (p < 0.05) value of total antioxidant capacity in frozen-thawed spermatozoa was monitored in all supplemented groups as relative to the control. The values of malondialdehyde (MDA) and nitric oxide (NO) were lower (p < 0.05) in NEGSO group compared with other groups. Both NEO and NEFO exhibited the same results for MDA, and NO levels (p > 0.05). All supplemented groups exhibited lower hydrogen peroxide levels (p < 0.05) as relative to the un-treated group. The lowest (p < 0.05) caspase 3 levels were verified in NEGSO treatment, followed by NEFO and NEO treatments. Post-thawed sperm showed ultrastructural damages in the control group, and theses damages were attenuated or resorted by the NEGSO, NEFO and NEO supplemented to freezing extender. In consequences with in vitro results regarding the sperm attribute, a greater pregnancy rate (92%) was observed in NEGSO group as compared with NEFO (88%), NEO (76%) and CON (68%) groups. Our findings demonstrate that NEGSO (3.5%) could be used as a new strategy in enhancing sperm functionality, potential fertility and reducing the oxidative damage and apoptosis markers. This could be significantly applicable for sperm physiology cryopreservation in the milieu of assisted reproduction systems.

Effect of dietary n-3 fatty acid and rooibos (Aspalathus linearis) supplementation on semen quality, sperm fatty acids and reproductive performance of aged male broiler breeders

The purpose of this study was to assess the effects of dietary fish oil (FO) and rooibos supplementation on semen quality, fatty acids composition and reproductive performance of aged male broiler breeders. Seventy-two 47-week-old Ross broiler breeder roosters were randomly assigned to a 2 × 3 factorial arrangements to include two FO concentrations (0% and 2%) and 3 rooibos concentrations (0%, 1.5% and 3%) for 13 weeks consecutive. The different diets affected semen parameters significantly (p < 0.05), except for the semen concentration and abnormality of the sperm. The sperm of the FO and 3% rooibos-treated group showed better motility and viability when compared to the other groups (p < 0.05). The susceptibility of semen to lipid peroxidation was increased in roosters fed the rooibos-free diets (p < 0.05), but it was reduced (p < 0.05) when the diet was supplemented with 1.5% and 3% rooibos. In addition, at 64 weeks, the highest concentration of testosterone was observed in the roosters fed a diet that included 2% FO and 3% rooibos (p < 0.05); however, the difference in testosterone levels between Week 52 and Week 64 was not significant (p > 0.05). The fertility rate of collected eggs from the FO and 3% rooibos group was higher (p < 0.05) than that of the other groups at the end of the experiment. In conclusion, dietary inclusion of FO along with rooibos improved seminal quality and reproduction performance in aged roosters.

Dietary flaxseed oil and vitamin E improve semen quality via propionic acid metabolism

Introduction

Flaxseed oil (FO) and vitamin E (VE) both have antioxidant effects on sperm. The present study investigated the effects of dietary supplementation with FO and/or VE on semen quality.

Methods

16 fertile Simmental bulls were selected and randomly divided into 4 groups (n = 4): the control group (control diet), FO group (control diet containing 24 g/kg FO), VE group (control diet containing 150 mg/kg VE) and FOVE group (control diet containing 150 mg/kg VE and 24 g/kg FO), and the trial lasted 10 weeks.

Results

The results showed that the addition of FO independently can increase sperm motion parameters, the levels of catalase (CAT), glutathione peroxidase (GSH-Px), testosterone (T) and estradiol (E2), while reduce oxidative stress in seminal plasma (P < 0.05). Supplement of VE independently can increased the motility, motility parameters, CAT and superoxide dismutase (SOD) levels, and reduce oxidative stress in seminal plasma (P < 0.05). There was an interaction effect of FO × VE on motility and reactive oxygen species (ROS), while GSH-Px and ROS were affected by week × VE 2-way interaction, levels of T and E2 were also affected by the dietary FO × week interaction (P < 0.05). The triple interaction effects of FO, VE and week were significant for malondialdehyde (MDA) (P < 0.05). Compared with the control group, sperm from the FOVE group had a significantly higher in vitro fertilization (IVF) rate, and subsequent embryos had increased developmental ability with reduced ROS levels at the eight-cell stage, then increased adenosine triphosphate (ATP) content and gene expression levels of CAT, CDX2, Nanog, and SOD at the blastocyst stage (P < 0.05). Metabolomic and transcriptomic results indicated that dietary supplementation of FO and VE increased the expression of the metabolite aconitic acid, as well as the expression of ABAT and AHDHA genes.

Conclusion

With in-silico analysis, it can be concluded that the effects of dietary FO and VE on improving semen quality and embryo development may be related to increased aconitic acid via the ABAT and AHDHA genes involved in the propionic acid metabolism pathway.

Cryopreservation of Semen in Domestic Animals: A Review of Current Challenges, Applications, and Prospective Strategies

Cryopreservation is a way to preserve germplasm with applications in agriculture, biotechnology, and conservation of endangered animals. Cryopreservation has been available for over a century, yet, using current methods, only around 50% of spermatozoa retain their viability after cryopreservation. This loss is associated with damage to different sperm components including the plasma membrane, nucleus, mitochondria, proteins, mRNAs, and microRNAs. To mitigate this damage, conventional strategies use chemical additives that include classical cryoprotectants such as glycerol, as well as antioxidants, fatty acids, sugars, amino acids, and membrane stabilizers. However, clearly current protocols do not prevent all damage. This may be due to the imperfect function of antioxidants and the probable conversion of media components to more toxic forms during cryopreservation.

Enhancement of sperm quality and fertility-related parameters in Hubbard grandparent rooster fed diets supplemented with soybean lecithin and vitamin E

The purpose of this study was to investigate the effect of dietary supplementation of different levels of soybean lecithin and vitamin E on semen quality parameters and some reproductive hormones in Hubbard grandparent roosters. The experiment was conducted in a 3 × 2 factorial arrangement with 3 levels of soybean lecithin (0, 1, and 2%) and 2 levels of vitamin E (0 and 300 mg/kg). Semen samples were collected on d 0, 20, 40 and 60 of the experiment and analyzed. Adding 1% soybean lecithin and vitamin E into the diet increased semen volume and sperm concentration, membrane integrity and viability (P < 0.05). Supplementing diets with 1 or 2% lecithin in addition to vitamin E significantly improved total motility and progressive motility (P < 0.05). Vitamin E significantly increased the amplitude of lateral head displacement (ALH) of sperm (P < 0.05). Although there was no effect on LH and FSH when diets were supplemented with vitamin E and 1 or 2% lecithin, testosterone concentration was increased (P < 0.05). Malondialdehyde (MDA) concentration was significantly lower in all 3 treatments containing vitamin E (P < 0.05). It can be concluded that supplementation of rooster diets with vitamin E and 1% lecithin can improve fertility related parameters in Hubbard grandparent roosters.

Effect of vitamin E supplementation on chicken sperm quality: A meta-analysis

Background and Aim:

Among several factors, the sperm quality of poultry is affected by the rooster’s body size and the availability of antioxidants like vitamin E. This study aimed to determine the effect of dietary vitamin E supplementation on rooster sperm quality through a meta-analysis.

Materials and Methods:

After verification and evaluation, a total of 19 articles were included in this study. Data, including dietary vitamin E, semen volume, concentration, total sperm cells, pH, motility, viability, percentage of dead and abnormal sperm, vitamin E sperm content, malondialdehyde (MDA) content, and testosterone levels, were tabulated in a database; these were subsequently analyzed using mixed modeling with vitamin E dose as a fixed effect and study identity as a random effect.

Results:

Dietary supplementation level of vitamin E significantly (p<0.001) affected sperm concentration, significantly affected motility (p<0.001), significantly affected sperm vitamin E (p<0.001), significantly affected viability (p<0.001), and significantly affected chicken sperm fertility (p=0.001). Vitamin E administration also significantly reduced the number of sperm cell deaths (p<0.001); however, increased dietary levels of vitamin E did not affect semen volume (p=0.853), pH (p=0.951), MDA (p=0.542), the percentage of abnormal sperm cells (p=0.343), nor testosterone levels (p=0.063).

Conclusion:

Dietary vitamin E supplementation is recommended for male chickens since it generally enhances the quality of their sperm.

Modulatory effects of pioglitazone as a ligand for the peroxisome proliferator-activated receptor on semen quality and fertility potential of broiler breeder roosters

Fertility potential in roosters is a crucial topic in broiler breeder reproduction which is thought to be associated with age. This study aims to investigate effects of 2 levels of pioglitazone (PIO) supplementation on peroxisome proliferator-activated receptor gamma (PPAR-γ) expression, semen quality, and fertility parameters of aged broiler breeder roosters. The efficacy of PIO was divided into 2 sections: receptor-dependent and receptor-independent. Expression of PPAR-γ mRNA and protein was assessed in sperm to monitor receptor-dependent actions. Sperm motility, velocity parameters, viability, mitochondrial activity, and apoptosis were assessed for the receptor-independent actions. Broiler breeder roosters were randomly assigned to 3 groups: 1) control received a basal diet (CTRL); 2) PIO-5 received a basal diet supplemented with 5 mg PIO/bird/day, and 3) PIO-10 received a basal diet supplemented with 10 mg PIO/bird/day. In addition, semen samples were collected from 24 Ross broiler breeder roosters at 30, 43, and 53 wk of age. Effects of PIO were significant in terms of total motility, straight-line velocity, mitochondrial activity, and apoptosis (P ≤ 0.05). Total motility, straight-line velocity and mitochondrial activity improved in both PIO groups (P ≤ 0.05) along with a significant reduction in early and late apoptosis in the PIO groups (P ≤ 0.05). Pioglitazone addition affected total motility, mitochondrial activity, early apoptosis and late apoptosis in a linearly and quadratically manner (P < 0.05). PPAR-γ mRNA and protein expression were not significantly upregulated by the different doses of PIO (P > 0.05). Similarly, fertility performance was not significantly changed in the PIO groups (P > 0.05). Moreover, PIO improved mitochondrial activity and decreased the apoptosis rate in the sperm of aged broiler breeder roosters. These improvements were associated with the receptor-independent actions of PIO and the mechanism of action of PIO did not appear to be affected by the PPAR-γ receptor in broiler breeder roosters.

Flaxseed Oil as a Source of Omega n-3 Fatty Acids to Improve Semen Quality from Livestock Animals: A Review

Simple Summary

In response to the conservation of threatened livestock species, different strategies to improve semen quality have been developed. However, spermatozoa remain sensitive to cryopreservation damages especially that of avian species, thus limiting the use of reproductive biotechnologies such as artificial insemination in the conservation programs. Improving semen quality through dietary inclusion of long-chain polyunsaturated fatty acids sources mainly omega n-3 has received research interest. This review explains the role of flaxseed oil as a source of omega n-3 fatty acids to improve semen quality. Comprehensive information elaborated in this review is believed to promote the use of flaxseed oil as an alternative source of omega n-3 fatty acids to fish oil. This is because fisheries are over-exploited and could collapse.

Abstract

The demand to conserve indigenous species through the cryo-gene bank is increasing. Spermatozoa remain sensitive to cryopreservation damages especially that of avian species thus limiting the use of reproductive biotechnologies such as artificial insemination in the conservation programs. Long-chain polyunsaturated fatty acid (LCPUFAs), specifically omega n-3, expanded a research interest to improve animal reproductive efficiency through improving spermatozoa quality. This is driven by the fact that mammals cannot synthesize omega-3 de-novo because they lack delta-12 and delta-15 desaturase enzymes thus supplemented in the diet is mandatory. Delta-12 and delta-15 add a double bond at the 12th and 15th carbon-carbon bond from the methyl end of fatty acids, lengthening the chain to 22 carbon molecules. Fish oil is a pioneer source of omega n-3 and n-6 fatty acids. However, there is a report that numerous fisheries are over-exploited and could collapse. Furthermore, processing techniques used for processing by-products could complement alterations of the amino acid profile and reduce protein retrieval. Alternatively, flaxseed oil contains ±52–58% of total fatty acids and lignans in the form of α-linolenic and linoleic acid. Alpha-linolenic acid (ALA,18:3n-3) is enzymatically broken-down de-novo by delta-6 desaturase and lengthened into a long-chain carbon molecule such as eicosapentaenoic acid (C20:5n-3). Nevertheless, controversial findings following the enrichment of diet with flaxseed oil have been reported. Therefore, this paper is aimed to postulate the role of flaxseed oil as an alternative source of omega n-3 and n-6 fatty acids to improve semen quality and quantity from livestock animals. These include the interaction between docosahexaenoic acid (DHA) and spermatogenesis, the interaction between docosahexaenoic acid (DHA) and testicular cells, and the effect of flaxseed oil on semen quality. It additionally assesses the antioxidants to balance the level of PUFAs in the semen.

Effects of Gossypium spp., Balanites aegyptiaca, and Sesamum indicum seeds oils on quality of chilled and frozen-thawed ram semen

Background and Aim:

Essential oils found frequently in plants are well known for their activities against bacteria, viruses, and fungi, and antioxidant properties. This study aimed to analyze egg yolk replacement by seed oils of Gossypium spp. (cotton), Balanites aegyptiaca (desert date), and Sesamum indicum (sesame) in semen extender, on ram sperm quality chilled at 4°C and frozen-thawed.

Materials and Methods:

Ejaculates were collected from adult rams and refrigerated at 4°C in a Tris-based extender containing 1.25%, 2.5%, 5%, and 10% of Gossypium spp., B. aegyptiaca, and S. indicum seed oils, to evaluate which were the two best extenders for comparison with BIOXcell, a commercial extender for deep freezing ram semen.

Results:

The data showed that sperm movements analyzed by the CASA system were faster in extenders supplemented with 2.5-5% of cottonseed oil and 1.25-10% of sesame oil, whereas in the extender containing B. aegyptiaca oil, all seminal parameters studied had the worst values. During the sperm-freezing process, 5% of cottonseed oil and 5% sesame seed oil were selected from the first study, with sesame oil reaching the best sperm quality. Thus, sperm motility and velocity were 44.14±13.99%, 24.44±12.6%, and 25.92±11.50%; and 20.26±9.56%, 8.76±6.38%, and 9.42±5.40%, respectively, for sesame oil, cottonseed oil, and BIOXcell.

Conclusion:

In summary, 2.5-10% of cottonseed oil and 1.25-10% of sesame seed oil can replace egg yolk in a Tris–egg yolk–based extender. Moreover, a Tris-based extender supplemented with 5% sesame seed oil could be an alternative for deep freezing ram semen, even though these results need to be confirmed with semen collected from rams with appropriate sexual rest.

Dietary supplementation of pumpkin seed oil and sunflower oil along with vitamin E improves sperm characteristics and reproductive hormones in roosters

This study evaluates the effects of pumpkin seed oil and sunflower oil along with vitamin E on the reproductive characteristics of aged roosters. Thirty Ross breeder roosters (45-wk-old) were assigned into 6 groups (5 birds/group) with the following diets: 1) control group (basal diet), 2) basal diet with 2% pumpkin seed oil as omega-3 fatty acid (PSO group), 3) basal diet with 2% sunflower oil as omega-6 fatty acid (SFO group), 4) basal diet with 200 mg/kg vitamin E (Control + vitE group), 5) basal diet and 2% pumpkin seed oil along with 200 mg/kg vitamin E (PSO + vitE group) and 6) basal diet and 2% sunflower oil along with 200 mg/kg vitamin E (SFO + vitE group). Roosters were fed on the experimental diets for 60 d and different characteristics of sperm characteristics including routine semen analysis and several sperm functional tests in every 20 d were examined. Reproductive hormones were also evaluated in 0 d and at the end of the trial. Semen volume and morphology were not affected by any of the diets. The roosters fed with pumpkin seed oil + vitE showed the higher percentage of sperm concentration, total motility, progressive motility, viability and membrane integrity and the lower lipid peroxidation (P ≤ 0.05). The group 5 (PSO + vitE) had numerically the lowest sperm with fragmented DNA (DNA Fr⁺) at 0 of the experiment and sperm with non-fragmented DNA (DNA Fr⁻) was lowest in group 6 (SFO + vitE) on da 40 the experiment. Testosterone level was not affected by the experimental diets (P > 0.05), however other hormones (LH and FSH) were affected. Based on the results, the supplementation of aged roosters’ diet with pumpkin seed oil + vitE improves reproductive performance which can be an appropriate strategy to preserve the reproductive performance of aged roosters.

Improving seminal quality and reproductive performance in male broiler breeder by supplementation of camphor

The current study was conducted to evaluate the effect of dietary camphor levels as a medicinal feed additive to improve semen quality, antioxidant capacity, reproductive hormones, and reproduction performance in roosters. For this purpose, thirty-five 29-wk-old Ross 308 broiler breeder roosters randomly were assigned to five experimental groups (seven birds/group) and received five doses of camphor containing 0, 50, 250, 750, and 1000 mg camphor/kg of feed for 12 wk consecutive. Semen quality parameters and motion characteristics of sperm were evaluated every 28 days and semen antioxidant capacity and plasma reproductive hormones concentration were tested at the end of the experiment. Also, at the end of the experiment, reproductive performance was assessed using artificial insemination. Among seminal quality parameters, sperm forward motility (88.96 vs 82.56%) and percentage of abnormal sperm (14.75 vs 15.86%) were improved in roosters fed 50 mg camphor/kg of feed compared to the control group (P < 0.05). Overall percentage of live sperm and plasma membrane integrity exhibited the quadratic responses to the levels of camphor (P < 0.08). The motion characteristics of sperm including progressive motility (28.81 vs 21.77%), average path velocity (VAP, 33.35 vs 26.83 μm/s), progressive velocity (VSL, 19.78 vs 16.48 μm/s), curvilinear line velocity (VCL, 52.87 vs 44.38 μm/s), the amplitude of lateral head displacement (ALH, 2.92 vs 2.46 μm) were improved in roosters fed 50 mg camphor/kg of feed compared to the control group (P < 0.05). However, dietary camphor levels linearly increased the percentage of linearity (LIN) and straightness (STR) (P < 0.05). A significant decrease in seminal plasma concentration of malondialdehyde (MDA) and an increase in superoxide dismutase (SOD) activity were observed in birds fed 1000 mg camphor/kg of feed (P < 0.05). Testosterone concentration was considerably increased by doses of 50 and 250 mg camphor/kg of feed compared to control (4.68, 4.79 vs 3.88 ng/mL) (P < 0.05). FSH and LH concentrations were not affected by camphor supplementation (P > 0.05). In the artificial insemination, fertility rate from both 50 mg camphor/kg of feed (88%) and 250 mg camphor/kg of feed (84%) was higher than control (75%) (P < 0.05). In conclusion, low levels of camphor, especially 50 mg camphor/kg of feed, improved seminal characteristics and, reproductive performance of roosters. Further researches are needed on the effect of higher levels of camphor and divulge of underlying mechanism on male's reproductive function.

Effects of dietary alpha-lipoic acid supplementation on the seminal parameters and fertility potential in aging broiler breeder roosters

High levels of polyunsaturated fatty acids in avian sperm cause more susceptibility to lipid peroxidation. Aging in roosters reduces the antioxidant capacity of sperm and thus fertility. The purpose of this study was to investigate the effects of different levels of alpha-lipoic acid (ALA) as a feed supplement to improve the semen quality and fertility parameters of aged broiler breeder roosters and identification of its most effective level. A total of forty-two roosters at 45 wk of age were randomly assigned to 7 treatments (0, 15, 40, 70, 95, 120, and 145 mg ALA/bird per day) for 8 wk. Semen parameters and body weight were assessed biweekly, and testosterone plasma levels were determined in the 8th wk of the experimental period. Artificial insemination was performed at the end of the experiment to evaluate the fertility potential. The dietary administration of ALA had no significant effects on body weight, semen volume, average path velocity, linearity, straightness, wobble, the amplitude of lateral head displacement, beat-cross frequency, sperm concentration, morphology, plasma testosterone level, fertility, or hatchability (P > 0.05). Alpha-lipoic acid supplementations resulted in a significant decrease in seminal malondialdehyde concentration and immotile (type D) sperms (P < 0.05). The total motility, progressive motility (types A + type B sperms), curvilinear velocity, straight-line velocity, viability, and membrane integrity of sperm improved with ALA dietary supplementations (P < 0.05). With increasing ALA levels, improvement in semen parameters had an incremental trend until the level of 95 mg ALA. Thus, 95 mg dietary ALA as an antioxidant supplement can improve semen quality of aging breeder roosters while higher doses resulted in no further improvement.

Nutritional modulation of fertility in male poultry

The increased consumption of protein derived from poultry demands greater poultry production, but increased poultry production (meat and eggs) is dependent on the fertility of the parent flocks. Clearly, the fertility of poultry flocks is associated with the fertility of both males and females, but the low numbers of males used for natural or artificial insemination mean that their role is more important. Thus, enhancing the semen volume, sperm concentration, viability, forward motility, and polyunsaturated fatty acids in sperm, as well as protecting against oxidative damage, could help to optimize the sperm membrane functionality, mitochondrial activity, and sperm-egg penetration, and thus fertility. Therefore, this review summarizes the nutritional factors that could improve the fertility of poultry males as well as their associated mechanisms to allow poultry producers to overcome low-fertility problems, especially in aging poultry males, thereby obtaining beneficial impacts on the poultry production industry.

Effect of dietary supplementation of whole flaxseed on sperm traits and sperm fatty acid profile in aged broiler breeder roosters

The objective of this study was to evaluate the effect of dietary supplementation of whole flaxseed on sperm traits and sperm fatty acid profile in aged broiler breeder roosters. Twelve Ross 308 broiler breeder roosters (age: 52 weeks; weight: 4,900 ± 210 g) haphazardly allotted to three dietary treatments (each treatment contained four replicates and one bird in each replicate) for six weeks. Treatments were different levels of flaxseed (0% flaxseed [GFL0], 2% flaxseed [GFL2] and 4% flaxseed [GFL4]). The feed intake quadratically decreased (p < .05) with increasing whole flaxseed levels for the period (58 to 60 weeks). Sperm traits (semen volume and sperm concentration, sperm total and forward motility, sperm viability and morphology, sperm plasma membrane functionality) were evaluated every two weeks (four times), and sperm fatty acid profile was assessed at the end of the experiment. Semen volume, sperm concentration and sperm morphology were not affected by treatments. On week 60, GFL2 group showed a significantly lower percentage of total and progressive sperm motility and sperm membrane functionality in comparison with the control and GFL4 groups. Also, sperm viability was lower in GFL2 group compared with other groups on week 58 (p < .05). In terms of sperm fatty acid profile, GFL2 group significantly reduced the percentage of linoleic acid (C18:2 [n-6]) in comparison with other groups. However, any of the other fatty acids were not affected by dietary flaxseed. In conclusion, dietary supplementation of whole flaxseed could not improve the quality of aged broiler breeder roosters' sperm in this study, nor it could alter the sperm fatty acid profile; thus, it seems necessary to use some antioxidants such as vitamin E in the diet of aged broiler breeder roosters, when supplementing the diets with oils or oilseeds such as flaxseed.

Changes in seminal parameters and hormonal profile with use of aromatase inhibitor in management of aging broiler breeder roosters

An excessive amount of aromatase enzyme reduces reproductive performance in aging roosters. Testosterone metabolism by aromatase enzyme is one of the reasons for reduced testosterone and lower fertility of aging roosters. The purpose of this study was to determine the effects of Exemestane (EX), as a steroidal aromatase inhibitor, on the seminal parameters and reproductive hormones of aging roosters. A total of 20 roosters (45 wk of age) were housed in individual cages and received a standard basal diet and oral EX capsules for 60 D at the daily doses per rooster (mg/rooster) in the following experimental groups: 0 mg (CTRL), 0.25 mg (Ex-0.25), 0.5 mg (Ex-0.5), and 1.5 mg (Ex-1.5). Sperm samples were obtained on days 1, 20, 40, and 60 of experiment. Blood samples were taken on days 1 and 60. The results indicated that different EX dosages affected semen parameters (P < 0.05) other than semen volume, morphology, apoptosis, and acrosome integrity. Various semen characteristics were significant (P < 0.05) during different times of the experiment, with the exception of semen volume, total motility, membrane integrity, morphology, apoptosis, and acrosome integrity. Roosters that received 0.5 mg of EX had higher percentages of sperm concentration, total motility, progressive motility, membrane integrity, viability, and mitochondrial activity (P < 0.05). There were lower concentrations of malondialdehyde in the CTRL (0 mg) and Ex-0.25 groups (P < 0.05). Although there was no significant difference in hormones at day 0 of the experiment (P > 0.05), roosters in the Ex-0.5 had higher concentration of testosterone as well as lower of aromatase activity at day 60 (P < 0.05). It can be concluded that EX improved semen parameters and testosterone, which ultimately can increase fertility in the aging broiler breeder roosters.

Dietary Cholesterol and Lipid Overload: Impact on Male Fertility

Lipid metabolic disorders due to poor eating habits are on the rise in both developed and developing countries, with a negative impact of the "Western diet" on sperm count and quality. Dietary lipid imbalance can involve cholesterol, fatty acids, or both, under different pathophysiological conditions grouped under the term dyslipidemia. The general feature of dyslipidemia is the development of systemic oxidative stress, a well-known deleterious factor for the quality of male gametes and associated with infertility. Sperm are particularly rich in polyunsaturated fatty acids (PUFA), an important characteristic associated with normal sperm physiology and reproductive outcomes, but also targets of choice for oxidative thrust. This review focuses on the effects of dietary cholesterol or different fatty acid overload on sperm composition and function in both animals and humans. The links between oxidative stress induced by dyslipidemia and sperm dysfunction are then discussed, including possible preventive or therapeutic strategies to preserve gamete quality, longevity when stored in cryobanking, and male fertility.