Influence of high levels of vitamin E on semen parameters of cocks

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.

Over 100 years of vitamin E: An overview from synthesis and formulation to application in animal nutrition

The groundbreaking discovery of vitamin E by Evans and Bishop in 1922 was an important milestone in vitamin research, inspiring further investigation into its crucial role in both human and animal nutrition. Supplementing vitamin E has been proved to enhance multiple key physiological systems such as the reproductive, circulatory, nervous and muscular systems. As the main antioxidant in the blood and on a cellular level, vitamin E maintains the integrity of both cellular and vascular membranes and thus modulates the immune system. This overview showcases important and innovative routes for synthesizing vitamin E on a commercial scale, provides cutting-edge insights into formulation concepts for successful product form development and emphasizes the importance and future of vitamin E in healthy and sustainable animal nutrition.

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.

Semen quality and sperm characteristics in broiler breeder cockerels fed vitamin E during hot season

Thirty-two Arbor Acres (AA) cockerels aged 27 weeks were used to determine the effect of vitamin E (VE) on the semen characteristics and sperm quality during hot season. The birds were fed diets containing 0, 50, 100 and 150mg VE kg-1 feed. There were 4 replicates and two birds per replicate. Semen collection was done thrice a week for three weeks in all birds. Dietary vitamin E significantly (p < 0.05) increased the semen volume (SV) and number of sperm cells (NS) in AA cockerels. CONTROL birds (0.71 mL) had lower SV than birds fed 150 mg VE (0.94 mL). Birds on 100 and 150 mg VE recorded similar NS, which was higher than 0 and 50 mg VE groups. The least NS was in the CONTROL group. Sperm abnormality gradually (p < 0.05) decreased as dietary VE increased from 0 to 150 mg. Significant (p < 0.01) effect of dietary VE was recorded in percentage live sperm (PLS). Semen from cockerels on VE treatment had higher PLS than the CONTROL. In conclusion, it may be beneficial to supplement the broiler breeder cockerel diet with VE up to 150 mg kg-1 feed during hot season as it increased SV, NS and PLS and decreased sperm abnormality.

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.

Vitamin E and Selenium Given as Dietary Supplements Accumulate in Tissues and Semen and Improve Reproductive Parameters in Older Red Cornish

The reproductive performance of broiler breeder chickens noticeably decreases toward the end of their commercial lives. Herein, we determined the effects of vitamin E and selenium dietary supplementation on semen traits, egg fertility (defined as fertilization and hatching rates) of adult (49-week-old) and older (63-week-old) Red Cornish breeders. We found that both vitamin E and selenium were concentrated in the liver and adipose tissue of adult and older Red Cornish breeders, and were transferred to the semen and egg yolk, respectively, in proportion to the level of supplementation. Vitamin E supplementation, in particular, improved ejaculate volume, total sperm count, sperm motility, and viability in both adult and older roosters, whereas selenium improved sperm motility and viability in the adult roosters. Egg fertility increased following supplementation with either vitamin E or selenium. The hatching rate also improved by both supplements in proportion to the level of supplementation. No significant synergistic effects of vitamin E and selenium were found. The levels of egg fertility and sperm trait improvements diminished with the age of the birds and depended on vitamin E and/or selenium doses. Thus, as dietary vitamin E and selenium supplements improved semen quality and egg fertility in these older Red Cornish broiler breeders, such birds could be maintained in flocks to prolong their reproductive output.

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.

The Effect of Dietary Supplementation of Vitamin E, Selenium, Zinc, Folic Acid, and N-3 Polyunsaturated Fatty Acids on Sperm Motility and Membrane Properties in Dogs

Sub-fertility represents a common challenge in canine reproduction. Different protocols, supplementing daily given quantities of micronutrients, were investigated to improve poor sperm concentration and/or function, which represent breeding major constraining factors in the canine species. Little information is available for dogs concerning the effect of a daily supplementation with a complex of vitamin E, zinc, selenium, folic acid, and n-3 polyunsaturated fatty acids (PUFA) on semen quality. Thus, the present study investigated this effect on semen motility and sperm membrane properties. Serial semen analyses from fourteen healthy normospermic dogs, fed with the same commercial diet, were performed on Days 0 (T0), 30 (T30), 60 (T60), and 90 (T90). Seven dogs were randomly included in the treatment (T) group, receiving a supplementation of vitamin E, zinc, selenium, folic acid, n-3 PUFA; and seven other subjects composed the control (C) group. Total Sperm Count (TSC), Computer-Assisted Sperm Analysis (CASA) indexes, mortality, and functional membrane integrity were assessed. The ANOVA compared results between groups and sampling times (p < 0.05). From T60, the supplementation significantly improved TSC, progressive motility, functional membrane integrity, and decreased mortality. Present results lead us to consider ameliorative effects of a two-month healthy diet supplementation on canine spermatozoa. The positive effects of the described balanced integration of micronutrients on sperm motility and prevention of oxidative stress should be considered, especially when decreased seminal parameters may result from inadequate intake, reduced absorption, increased losses or demand, or to attenuate the impact of age.

Selenium and vitamin E supplementation enhances the antioxidant status of spermatozoa and improves semen quality in male dogs with lowered fertility

Studies showed a beneficial effect of supplementation with selenium (Se) and vitamin E on semen quality. The aim of the study was to investigate the effect of Se and vitamin E supplementation on the antioxidant status of spermatozoa and semen quality in dogs with lowered fertility. Ten dogs were supplemented daily with Se (6 μg/kg organic Se yeast) and vitamin E (5 mg/kg) per os for 60 days. Control group consisted of 10 males without the supplementation. Semen was collected on day 0, 30, 60 and 90. Sperm quality parameters were evaluated using CASA and a microscope. Concentrations of Se and vitamin E in blood as well as glutathione peroxidase (GSH-Px) activity and total antioxidant capacity (TAC) in the spermatozoa were determined. After 60 days of supplementation the concentration of spermatozoa, the majority of motility indicators and the percentage of normal morphology and live spermatozoa increased significantly (p < .05). An increase (p < .05) in concentration of Se and vitamin E in blood and GSH-Px-activity and TAC in the spermatozoa was detected. The study results indicate that Se and vitamin E supplementation for 60 days enhances the antioxidant status of spermatozoa and improves the quality of the semen in dogs with lowered fertility.

Dietary Vitamin E Is More Effective than Omega-3 and Omega-6 Fatty Acid for Improving The Kinematic Characteristics of Rat Sperm

Objective

Although key roles for dietary vitamin E (VITE) and fatty acid (FA) in fertility have been confirmed, limited data are available on the effects of VITE alone, or a constant level of VITE supplemented by dietary omega-6 and omega-3 FAs in combination on male reproduction. Consequently in this paper, the effects of VITE, sunflower oil, fish oil and their combination on rat sperm were investigated.

Materials and Methods

We divided 50 mature male Wistar rats into 5 groups (n=10) in a experimental completely randomized design for eight weeks: i. Control (CTR): standard diet; ii. Vitamin E diet (VITE): 2 times greater than recommendations; iii. Sunflower oil group (n-6) [gavaged with 0.5 ml/day/rat sunflower oil+VITE diet]; iv. Fish oil group (n-3): [gavaged with 0.5 ml/day/rat fish oil+VITE diet] and v. n-3+n-6 group [gavaged with 0.3 ml fish oil/day/rat+0.2 ml sunflower oil/day/rat+VITE diet]. The sperm parameters were measured by computer assisted semen analyzer (CASA). All data were analyzed with SPSS software.

Results

Feed intake decreased in groups which were administered sunflower oil compared with the other groups (P<0.05). The groups which received only VITE or fish oil+VITE had a significantly higher concentration of sperm compared with the n-6+n-3 and CTR group (P<0.05). VITE and n-3 showed significant improved progressive motility compared to the CTR group, whereas the n-6 and n-6+n-3 groups were in the middle (P<0.05). The highest sperm kinematic parameters were observed in the VITE only group. There was no strong correlation between sperm parameters and blood lipid profiles.

Conclusion

Dietary VITE and fish oil+VITE can improve sperm quality. Our findings can be a focus for improvements in sperm quantity and motility in fertile animals using only dietary VITE.

Effects of dexamethasone treatment (to mimic stress) and Vitamin E oral supplementation on the spermiogram and on seminal plasma spontaneous lipid peroxidation and antioxidant enzyme activities in dogs

The objective was to determine if treatment with dexamethasone (to mimic stress) has a deleterious effect on the spermiogram and on the composition of seminal plasma in the dog and whether adverse effects were reduced by oral supplementation with Vitamin E. Eighteen adult male Rottweiler dogs were randomly allocated in a 2 x 2 factorial treatment design (with or without dexamethasone treatment versus with or without Vitamin E supplementation). Dogs in the supplemented group received 500 mg of alpha-tocopherol (Vitamin E)/dog/day per os for 10 weeks. Dexamethasone (0.01 mg/kg/day i.m.) was given once daily for 7 days, starting 7 days after the onset of Vitamin E supplementation. Food intake, body condition score and body weight were assessed daily. Semen collections (digital manipulation) were performed twice weekly for 14 weeks and blood samples (for plasma concentrations of cortisol and testosterone) were collected once a week. Dexamethasone treatment significantly reduced ejaculate volume and increased thiobarbituric acid-reactive substances (TBARS) in the seminal plasma. In contrast, supplementation with Vitamin E increased sperm motility, vigor and concentration and decreased the percentage of major sperm defects. In conclusion, dexamethasone treatment (to mimic stress) had a deleterious effect on the spermiogram and on the seminal plasma lipid peroxidation in dogs; however, some of these effects were prevented by oral supplementation with Vitamin E.

Sperm preparation for ART

The onset of clinical assisted reproduction, a quarter of a century ago, required the isolation of motile spermatozoa. As the indication of assisted reproduction shifted from mere gynaecological indications to andrological indications during the years, this urged andrological research to understand the physiology of male germ cell better and develop more sophisticated techniques to separate functional spermatozoa from those that are immotile, have poor morphology or are not capable to fertilize oocytes. Initially, starting from simple washing of spermatozoa, separation techniques, based on different principles like migration, filtration or density gradient centrifugation evolved. The most simple and cheapest is the conventional swim-up procedure. A more sophisticated and most gentle migration method is migration-sedimentation. However, its yield is relatively small and the technique is therefore normally only limited to ejaculates with a high number of motile spermatozoa. Recently, however, the method was also successfully used to isolate spermatozoa for intracytoplasmic sperm injection (ICSI). Sperm separation methods that yield a higher number of motile spermatozoa are glass wool filtration or density gradient centrifugation with different media. Since Percoll as a density medium was removed from the market in 1996 for clinical use in the human because of its risk of contamination with endotoxins, other media like IxaPrep, Nycodenz, SilSelect, PureSperm or Isolate were developed in order to replace Percoll. Today, an array of different methods is available and the selection depends on the quality of the ejaculates, which also includes production of reactive oxygen species (ROS) by spermatozoa and leukocytes. Ejaculates with ROS production should not be separated by means of conventional swim-up, as this can severely damage the spermatozoa. In order to protect the male germ cells from the influence of ROS and to stimulate their motility to increase the yield, a number of substances can be added to the ejaculate or the separation medium. Caffeine, pentoxifylline and 2-deoxyadenosine are substances that were used to stimulate motility. Recent approaches to stimulate spermatozoa include bicarbonate, metal chelators or platelet-activating factor (PAF). While the use of PAF already resulted in pregnancies in intrauterine insemination, the suitability of the other substances for the clinical use still needs to be tested. Finally, the isolation of functional spermatozoa from highly viscous ejaculates is a special challenge and can be performed enzymatically to liquefy the ejaculate. The older method, by which the ejaculate is forcefully aspirated through a narrow-gauge needle, should be abandoned as it can severely damage spermatozoa, thus resulting in immotile sperm.