Packed Sperm Volume Research Articles

Effect of dietary onion (Allium cepa L.) powder as an antioxidant on semen quality, blood biochemicals, and reproductive parameters, as well as immunological variables of rabbit bucks under severe heat stress.

This study aimed to evaluate the antioxidant effects of onion (Allium cepa L.) powder on the immunological variables, redox state, and semen quality of rabbit bucks exposed to severe heat stress. Thirty-six mature bucks (7 months old) were divided into three groups consistingof 12 bucks each, namely group I, control; group II, 400 mg onion powder/kg diet; and group III, 800 mg onion powder/kg diet. The quality of semen was evaluated for volume, pH, motility, concentration, total sperm output, viability, and packed sperm volume. Blood samples were collected in the 12th week for estimation of red blood cells (RBC), white blood cells (WBC), and erythrocytic indices. Serum proteins, glutamate oxaloacetate (GOT), glutamate pyruvate transaminase (GPT), urea, creatinine, testosterone, follicle-stimulating hormone (FSH), luteinizing hormone (LH), immunoglobulins, malondialdehyde (MDA), total antioxidant capacity (TAC), glutathione, superoxide dismutase (SOD), and catalase (CAT) were measured. The temperature-humidity index (THI) obtained was within the range of 28.85-33.08 indicating severe heat stress. The results show that mass and individual motility, concentration, total sperm output, sperm viability, and packed sperm volume were higher (P < 0.05) in groups II and group III, with group III having the highest (P < 0.05) levels compared to group I. Compared to group I, groups II and III had higher (P < 0.05) concentrations of RBC, MCV, MCH, FSH, LH, SOD, and catalase. The highest concentration (P < 0.05) of GPT was obtained in group III compared to other groups. The highest concentration of IgG (P < 0.05) was obtained in group II while the lowest was in group I. In conclusion, dietary supplementation with onion powder at 400 or 800 mg/kg diet improves semen quality, RBC, FSH, LH, SOD, catalase, and IgG while ameliorating the adverse effects of heat stress and improve the health and reproduction of rabbits.

Tramadol injection as dosage form -Induced deterioration in reproductive performance of male rabbits

Injections are usually more expensive than tablets, but they may be required less often since they are more concentrated, whereas a person may need to take a tablet more regularly, thus consuming a large volume. when we administer a drug via oral rout ,its meant to be absorbed by stomach or intestinal mucosa ,but its so happens that, gastric acid, food ,other drugs and many other factor come into the play and retarded the drug absorption ,metabolized in intestinal mucosal cells even before it can reach to liver or target tissue(first-pass metabolism)thus decrease the effective amount reaching to circulation, Now, a drug given through injection reaches circulation at cent percent level and show prompt action which is earnestly required at the moment ,it also decrease the dose and systemic side effects . also the tablets formulation contain the excipient like filler ,diluents for the purpose of long -term stabilization ,bulking up tablet formulations making concentration of drug less in tablets and need more dose to give the therapeutic action. Tramadol is a potent analgesic effective in the treatment of mild to severe pains. However, the use of the drug can pose a threat to other organs and systems. Therefore, this study was designed to investigate the effect of tramadol injection as dosage form on reproductive parameters in male rabbits. Tenth rabbits were randomly divided into two equal groups (each group five rabbits). The first group was used as a control. The second group was used to study the effect of tramadol (50 mg/kg body weight) for six weeks. Results obtained showed that tramadol significantly (P&lt;0.05) decreased libido (by increasing the reaction time), ejaculate volume, sperm concentration ,total sperm output, sperm motility (%), total motile sperm per ejaculate (TMS), packed sperm volume (PSV), total functional sperm fraction (TFSF), normal and live sperm and semen initial fructose. While initial hydrogen ion concentration (pH) and dead and abnormal sperm were increased (P&lt;0.05). Live body weight (LBW) and relative weights of testes (RTW) were significantly (P&lt;0.05) decreased. Concentrations of thiobarbituric acid-reactive substances (TBARS) were significantly (P&lt;0.05) increased in plasma of rabbits treated with tramadol compared with control. The study showed the harmful effects of tramadol on the reproductive performance on male rabbits. Keywords: Tramadol Injection; Rabbits; Semen; Testosterone

Effect of vitamin E-selenium supplementation on some semen quality traits of Muscovy drakes.

A total of 12, 36-week-old of Muscovy drakes were divided randomly into three equal groups (4 individuals each) and subjected to supplementation of VE-Se in combine form in drinking water. The first group was served as control group (C), while the second and third groups (T1 and T2) were supplemented with 1.0g/l and 1.5g/l of VE-Se in drinking water, respectively. The study was performed at poultry research station which belongs to department of poultry production, faculty of agricultural, Ain Shams University and lasted 30-dayes period during summer season. Semen quality traits in terms of ejaculate volume (ml), spermatozoa concentration (×109), sperm motility (%), dead and live (%), PH value and abnormal sperms (%) were determined. Sperm reserves in ducts, seminiferous tubules diameter (STD) and relative spermatogenic activity were also studied. The obtained results indicated that addition of vitamin E-Se improved ejaculate volume, sperm concentration and motility score, while reduced the percentage of abnormalities and dead sperms. Results showed that semen ejaculate volume was significantly increased (P<0.05) with increasing the level of VE-Se supplementation in drinking water. Spermatozoa concentration, progressive motility (%), and packed sperm volume were increased significantly with VE-Se treatment. The percentages of dead and abnormal spermatozoa were significantly decreased (P<0.01) in VE-Se treated compared with the control drakes. Concerning with the effect of two levels (T1 and T2) of VE-Se supplementation in drinking water of Muscovy drakes on the morphometric traits of testis, the obtained results showed that highly significant effects of antioxidant (VE-Se) supplementation on the morphometric of seminiferous tubules (p < 0.05) and the higher values of sperm reserves and spermatogenic activity percentage in both T1 (4.4/ml×109 and 82.8%) and T2 (4.5/ml×109 and 83.0%) compared with control group (3.2/ml×109 and 61.3%). We conclude that VE-Se supplementation could lead to greater economic benefits through increased reproductive efficiency within the ducks production industry.

Effect of Phthalates residues in plastic bottled waters on reproductive toxicity and oxidative stress in male rabbits

Phthalates are a genealogy of man-made chemical compounds improved in the last hundred to be employment in the devise of plastics, solvents, and personal care products. They are colorless, odorless, oily liquids that do not evaporate easily and do not. Phthalate esters are widely used as plasticizer. They can migrate from plastic materials to the environment. Exposure to some of these compounds may increase the risk of getting cancer. The experiment was designed to study toxic effects of Di-(2-ethylhexyl) phthalate (DEHP) on semen characteristics, testosterone levels, testicular lipid peroxidation and testicular antioxidants in male New-Zealand white rabbits for 12 weeks. Results obtained showed that DEHP significantly (P&lt;0.05) decreased libido (by increasing the reaction time), ejaculate volume, sperm concentration, total sperm output, sperm motility (%), total motile sperm per ejaculate (TMS), packed sperm volume (PSV), total functional sperm fraction (TFSF), normal and live sperm and semen initial fructose. Also, testosterone levels, body weight (BW), relative weights of the testes (RWT) and epididymis (RWE) were decreased. Thiobarbituric acid-reactive substances and lactate dehydrogenase were increased, while glutathione S-transferase, transaminases and phosphatases were decreased in seminal plasma of rabbits treated with DEHP compared to control. Chemically bind to the material they are added to quality assurance scheme for residue monitoring in water is quite important. Although, one cannot avoid phthalate contamination in bottled waters due to the manufacturing process, but at least special care should be taken regarding their storage conditions.

EFFECTS OF DIETARY BEE POLLEN AND MANNAN OLIGOSACCHARIDE ON SEMEN QUALITY IN RABBITS UNDER EGYPTIAN SUMMER CONDITIONS

The objectives of the present study were to verify the effect of using bee pollen and mannan oligosaccharide (MOS) in the feed mixture on semen quality and reduce the effect of lipid peroxidation of V-line rabbit buck semen during Egyptian hot summer season. A total number of 16 mature V line (VL) rabbit bucks 7-8 months-old of proven fertility with an average initial live body weight of 3.52±0.32 kg were classified into four homogeneous treatment groups of 4 bucks. Bucks were kept under a continuous 16 h light/8 h dark photoperiod and the ambient temperature ranged from 27.3 to 30.3 °C and relative humidity ranged from 72.8 to 75.4%. The estimated temperature-humidity index value indicated that during the experimental period rabbit bucks were exposed to severe heat stress. Four experimental diets were formulated to represent four dietary treatments. Bucks in the first treatment group were given the basal diet without supplementation and served as a control group, the second group was given 0.5 % MOS in their diet, while the third and fourth groups included bucks with supplementation of 0.1 and 0.2 % bee pollen in their diets, respectively. Results show that addition of 0.2 % bee pollen resulted insignificant decrease in semen hydrogen ion concentration (pH) as compared with the control and the other experimental feed additives. Addition of MOS, 0.1 and 0.2 % bee pollen significantly increased individual sperm motility, beside, these feed additives numerically increased ejaculate volume and sperm concentration as compared with the control group. Administration of 0.2 % bee pollen insignificantly increased live sperm percentage and mass activity by 13.2 and 27.4 %, respectively. Numerical increase in packed sperm volume (PSV) percentage amounted to 9.8 % due to administration of 0.2 % bee pollen. On the other hand, it was observed that MOS and bee pollen improved testosterone concentration and acrosome action percentage in comparison with the control group. Numerical decrease in seminal plasma MDA concentration, with significant increase in seminal plasma TAC due to MOS and bee pollen supplementation in comparison with the control group. In conclusion, results indicated that MOS and bee pollen improved semen quality and antioxidant status of rabbit bucks during Egyptian summer season.

Zearalenone-induced Deterioration in Reproductive Performance and Seminal Plasma Biochemistry of Male Rabbits

AbstractZearalenone (ZEA) is a nonsteroidal mycotoxin, produced by various fungi of the Fusarium genus; Zearalenone exhibits estrogenic and anabolic properties in several animal species, including human beings. Zearalenone contamination of food is caused either by direct contamination of grains, fruits, and their product or by ―carry-over‖ of mycotoxins and their metabolites in animal tissues, milk, and eggs after intake of contaminated feedstuff.Despite Zearalenone has toxicity and carcinogenicity.Detoxification strategies for contaminated foods and feeds to reduce or eliminate the toxic effects of ZEA by chemical, physical, and biological methods are crucial to improve food safety, prevent economic losses, and reclaim contaminated productsHowever; there is no enough data on the reproductive toxicity of Zearalenone in adult male.Therefore, the present investigation aimed to elucidate the toxicity of different doses of Zearalenone on reproductive performance, enzyme activities in seminal plasma and growth performance of males New Zealand white rabbits. Twenty rabbits were divided into 4 equal groups, first group was used as control, second group was treated with 0.5 μg/kg BW, third group was treated with 5 μg/kg BW and the fourth group was treated with 10 μg/kg BW of Zearalenone. Animals were treated orally every day for 12 weeks. Results obtained showed that Zearalenone significantly (P < 0.05) decreased libido (by increasing the reaction time), ejaculate volume, sperm concentration, total sperm output, sperm motility (%), total motile sperms per ejaculate (TMS), packed sperm volume (PSV), total functional sperm fraction (TFSF), normal and live sperms and semen initial fructose. While, initial hydrogen ion concentration (pH) and dead and abnormal sperms were increased (P < 0.05). Live body weight (LBW), feed intake (FI) and, aspartate aminotransferase (AST), alanine aminotransferase (ALT) and acid phosphatase (ACP) were significantly (P < 0.05) decreased. It was suggested that Zearalenone exerted a significant adverse effect on reproductive performance of male rabbits and the effects were in a dose- dependent manner.

β-Cryptoxanthin ameliorates the reproductive toxicity of chlorpyrifos in male rabbit

Exposure to pesticides became a routine and increasingly risky phenomenon. The harmful effects of occupational exposure to pesticides on health are irreversible in some cases. Chlorpyrifos is a broad spectrum organophosphorus insecticide that is widely used in agriculture, horticulture, and in domestic and urban pest control. Chlorpyrifos alters reproductive function by altering the activity of the pituitary-thyroid and pituitary-adrenal axes giving credence to its endocrine disrupting effect. β-Cryptoxanthin is a provitamin A carotenoid. β-cryptoxanthin is an antioxidant and may help prevent free radical damage to biomolecules. In the present study, we investigated the role of β-Cryptoxanthin in alleviating the negative effects of chlorpyrifos on reproductive characteristics in rabbits. Thirty mature male rabbits were randomly divided into five equal groups of six rabbits in each. Group 1 served as control. Group 2 was given β-Cryptoxanthin. Group 3 was orally given chlorpyrifos. Group 4 was given the combination of chlorpyrifos and β-Cryptoxanthin (5 mg/kg). Group 5 was given the combination of chlorpyrifos and β-Cryptoxanthin (10 mg/kg). The results showed that body weight, relative weights of testes and epididymis, feed intake, and plasma testosterone concentration were decreased significantly (P < 0.05) in rabbits treated with chlorpyrifos as compared to control or β-Cryptoxanthin-treated groups. Treatment with chlorpyrifos decreased (P < 0.05) semen ejaculate volume, packed sperm volume, sperm concentration, total sperm output, sperm motility, total motile sperm per ejaculate, total functional sperm fraction, normal sperm, and initial fructose as compared to control and β-Cryptoxanthin-treated rabbit groups. From the present results, it can be concluded that coadministration of β-Cryptoxanthin to chlorpyrifos-treated animals ameliorated the induced sperm quality damage and significantly improved the sperm parameters.

Aluminium-induced deterioration in reproductive performance and seminal plasma biochemistry of male rabbits: Protective role of ascorbic acid

Aluminium (Al) has been proposed as an environmental factor that may contribute to some diseases, affect several enzymes and other biomolecules and induced free radical-mediated cytotoxicity. Also, Al induced reproductive toxicity and exerted a significant adverse effect on the steroidogenesis. The antioxidant ascorbic acid (AA) plays an important role in various physiological processes in the body including detoxification of different toxic materials. Therefore, the present investigation aimed to elucidate possible protective effects of AA in alleviating the toxicity of aluminium chloride (AlCl 3) on reproductive performance, lipid peroxidation and enzyme activities in seminal plasma of male New Zealand white rabbits. Six rabbits per group were assigned to one of four treatment groups: 0 mg AA and 0 mg AlCl 3/kg body weight (BW) (control); 40 mg AA/kg BW; 34 mg AlCl 3/kg BW; 34 mg AlCl 3 plus 40 mg AA/kg BW. Rabbits were orally administered their respective doses every other day for 16 weeks. Results obtained showed that AlCl 3 significantly ( P < 0.05) decreased libido (by increasing the reaction time), ejaculate volume, sperm concentration, total sperm output, sperm motility (%), total motile sperm per ejaculate (TMS), packed sperm volume (PSV), total functional sperm fraction (TFSF), normal and live sperm and semen initial fructose. While initial hydrogen ion concentration (pH) and dead and abnormal sperm were increased ( P < 0.05). Live body weight (LBW), feed intake (FI) and relative weights of testes (RTW) and epididymis (REW) were significantly ( P < 0.05) decreased. Concentrations of thiobarbituric acid-reactive substances (TBARS) were significantly ( P < 0.05) increased in seminal plasma of rabbits treated with AlCl 3 compared with control. While, activities of glutathione S-transferase (GST), aspartate aminotransferase (AST), alanine aminotransferase (ALT) and acid phosphatase (AcP) were significantly ( P < 0.05) decreased. Ascorbic acid alone significantly increased LBW, FI, RTW, REW, semen characteristics and seminal plasma enzymes, and decreased the levels of free radicals. Also, the present study showed that ascorbic acid might be effective in the protection of aluminium-induced reproductive toxicity. It was suggested that AlCl 3 exerted a significant adverse effect on reproductive performance of male rabbits. Furthermore, AA could be able to antagonize the toxic effects of AlCl 3 and improved semen quality of male rabbit.

Reproductive performance, blood testosterone, lipid peroxidation and seminal plasma biochemistry of rabbits as affected by feeding Acacia saligna under subtropical conditions

Thirty-two New Zealand White growing rabbits (eight-week old) were used to determine the effect of feeding acacia-based diets on semen characteristics, plasma testosterone, free radicals, seminal plasma enzymes and lipids. Rabbits were randomly assigned to four equal groups. The first group (control) was fed a basal diet only, and the other three groups were fed other three diets, as follows: 80% of basal diet+20% of acacia leaves (low), 60% of basal diet+40% of acacia leaves (medium) and 40% of basal diet+60% of acacia leaves (high), respectively for 32 week. Semen samples were collected throughout the last 12 week of the experimental period. Rabbits fed on different levels of Acacia showed no significant changes in libido (reaction time), ejaculate volume, sperm concentration, packed sperm volume and initial hydrogen ion concentration compared to control. However, low and/or medium levels of Acacia caused significant (P<0.05) increase in total sperm output (TSO), sperm motility (%), total motile sperm per ejaculate (TMS), normal sperm, total functional sperm fraction (TFSF), semen initial fructose, live sperm and plasma testosterone. On the other hand, high level of Acacia did not show any significant change in TSO, sperm motility (%), TMS, initial fructose, TFSF or testosterone, while live and normal sperm decreased. All levels of Acacia caused a significant decrease in the concentrations of thiobarbituric acid-reactive substances (TBARS) and an increase in the activity of glutathione S-transferease. The activities of lactate dehydrogenase (LDH), aminotransferases and phosphatases were significantly increased in seminal plasma of animals fed low or medium levels of Acacia. Seminal plasma total lipid, triglyceride, low density lipoprotein and free fatty acids were significantly (P<0.05) decreased in low or medium levels of Acacia. On the other hand, total cholesterol, percentage cholesterol (out of total lipids) and high density lipoprotein were significantly (P<0.05) increased in seminal plasma of rabbits fed on low or medium levels of Acacia. High level of Acacia did not cause any changes in the previous parameters. It can be concluded that up to 40% Acacia leaves could be used successfully and safely in the diet of rabbits without adversely affecting their reproductive performance under subtropical conditions.

Protective role of ascorbic acid to enhance reproductive performance of male rabbits treated with stannous chloride

The objective of this study was to determine the protective role of ascorbic acid (AA, 40 mg/kg BW) on reproductive performance of male New Zealand White rabbits given sublethal dose (20 mg/kg BW every other day for 12 weeks) of stannous chloride (SnCl2). Results showed that treatment with SnCl2 caused a decrease (P<0.05) in libido (by increasing the reaction time), ejaculate volume, sperm concentration, total sperm output, sperm motility (%), total motile sperm per ejaculate (TMS), packed sperm volume (PSV), total functional sperm fraction (TFSF), normal and live sperm and semen initial fructose. Dead sperm and initial hydrogen ion concentration (pH) were increased. While, relative weights of testes (RTW) and epididymis (REW) were decreased. On the other hand, live body weight (LBW) and dry matter intake (DMI) did not change. Treatment with AA alone caused significant increase in LBW, DMI, RTW, REW and semen characteristics compared to control group. Also, the presence of AA with SnCl2 minimized its harmful effects. Results obtained revealed suggest that assessment of reproductive toxicity of stannous chloride needs to be addressed, and may presently be underestimated. Also, the beneficial influences of AA in counteracting the toxic effects of SnCl2 and improved the reproductive performance of male rabbit was demonstrated.

Effect of Isoflavones on Reproductive Performance, Testosterone Levels, Lipid Peroxidation, and Seminal Plasma Biochemistry of Male Rabbits

The objective of this study was to determine the effect of either 2.5 mg/kg Body Weight or 5 mg/kg Body Weight (BW) doses of isoflavones on semen quality, testosterone levels, lipid peroxidation and semen biochemistry of male New Zealand White rabbits. Animals were given both 2.5 mg/kg BW and 5 mg/kg BW doses of isoflavones. The tested doses were given to rabbits orally every other day for 13 weeks. Treatment with isoflavones caused an increase (p < 0.05) in libido (by decreasing the reaction time), sperm concentration, sperm motility (%), total motile sperm per ejaculate (TMS), packed sperm volume (PSV), total functional sperm fraction (TFSF), total sperm output, initial fructose concentration and normal sperm, while dead sperm was reduced compared to control animals. On the other hand, ejaculate volume, initial hydrogen ion concentration (pH) and plasma testosterone levels did not change in treated animals with both doses of isoflavones as compared to control. Concentrations of thiobarbituric acid-reactive substances (TBARS), total lipids, and low density lipoprotein were significantly (p < 0.05) reduced in seminal plasma of rabbits treated with either 2.5 mg/kg BW or 5 mg/kg BW doses of isoflavones. While, the activities of glutathione S-transferase (GST), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), alanine aminotransferase (ALT), acid phosphatase (AcP), and alkaline phosphatase (AlP) were significantly (p < 0.05) increased in seminal plasma of treated animals. Also, total cholesterol, percentage cholesterol (out of total lipids), and high density lipoprotein were significantly (p < 0.05) increased, while triglyceride did not change in seminal plasma of treated animals. Supplementation at either level of isoflavones did not cause changes in live body weight (LBW), dry matter intake (DMI), and relative weights of testes and epididymis. The present results showed that either 2.5 mg/kg BW or 5 mg/kg BW doses of isoflavones caused an improvement of some semen characteristics and did not have negative effects on male fertility.

Protective Role of Isoflavones Against the Toxic Effect of Cypermethrin on Semen Quality and Testosterone Levels of Rabbits

Cypermethrin is considered as one of the endocrine disruptors. Isoflavones play an important role in various physiological processes in the body. It has both estrogenic and antioxidant effects. The objective of this study was to evaluate the protective role of isoflavones (2 mg/kg B.W) on semen quality and plasma testosterone levels of male New Zealand White rabbits given sublethal dose (24 mg/kg BW every other day for 12 weeks) of cypermethrin. Results showed that treatment with cypermethrin caused a significant decreases (P < 0.05) in ejaculate volume, sperm concentration, total sperm output, sperm motility (%), total motile sperm per ejaculate (TMS), packed sperm volume (PSV), semen initial fructose and plasma testosterone. In addition, live body weight (LBW), dry matter intake (DMI) and relative weights of testes and epididymis were decreased. On the other hand, treatment with cypermethrin increased (P < 0.05) the numbers of abnormal and dead sperms, and initial hydrogen ion concentration (pH). Results indicated that the presence of isoflavones together with cypermethrin was capable to minimize its harmful effects. Treatment with isoflavones alone had positive effects on some semen characteristics in spite of it is considered as estrogen‐like compound. Since it causes significant increases in libido (by decreasing the reaction time), PSV, sperm motility and TMS, while abnormal and dead sperm were reduced compared to control animals. Meanwhile, isoflavones had no negative effect on ejaculate volume, total sperm output, sperm concentration, initial fructose concentration, pH and plasma testosterone levels. Results demonstrated the beneficial influences of isoflavones in reducing the negative effects of cypermethrin on reproductive characteristics of mature male rabbits. Interestingly, data showed that isoflavones alone caused an improvement in some semen quality and had no negative effects on male fertility, and did not have negative effects on male fertility.

Effect of ascorbic acid and Vitamin E supplementation on semen quality and biochemical parameters of male rabbits

The objective of this study was to determine the effects of supplementation of ascorbic acid, Vitamin E (Vit. E) and their combination in drinking water on sperm characteristics, lipid peroxidation (LPO) and seminal plasma enzymes of mature male rabbits. Twenty-four male New Zealand White rabbits (5 months old) were given drinking water supplemented with ascorbic acid (1.5 g/l), Vit. E (1.0 g/l) and ascorbic acid+Vit. E (1.5+1.0 g/l) for 12 weeks. Vitamin supplementation in drinking water increased feed intake, but body weight gain was not significantly affected. Concentrations of thiobarbituric acid-reactive substances (TBARS) were significantly ( P<0.05) reduced in seminal plasma of treated groups compared with the control. Treatment with ascorbic acid, Vit. E, and their combination significantly ( P<0.05) increased lipido (reaction time), ejaculate volume, sperm concentration, total sperm output, sperm motility index, total motile sperm, packed sperm volume, initial hydrogen ion concentration (pH), and semen initial fructose concentration. Abnormal and dead sperm were significantly ( P<0.05) decreased in treated animals. The activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) were significantly ( P<0.05) decreased, whereas glutathione S-transferase (GST) showed a significant increase in seminal plasma of treated animals compared with the controls. The results from this study indicated that supplementation of drinking water with antioxidant ascorbic acid, Vit. E and their combination reduced the production of free radicals and can improve rabbit semen quality, but the greater improvement seemed to be from Vit. E.

Milt production in common carp (Cyprinus carpio): stimulation by a goldfish steroid pheromone

This study examined the effect of a putative steroidal pheromone, 17α,20β-dihydroxy-4-pregnen-3-one (17,20β-P) on milt volume and serum gonadotropin-II in precocious male common carp (40–285 g). 17,20β-P significantly increased both milt volume (14–18 h post-exposure) and GtH level (90 min post-exposure) at both doses tested (5 × 10−11 and 5 × 10−10 M in aquarium water), whereas a conjugated form of 17,20β-P (17,20β-P-sulphate) was ineffective at the only dose tested (5 × 10−11 M). Increases in milt, packed sperm volume, and GtH following exposure 5 × 10−10 M 17,20β-P also were compared to those induced by injection of Ovaprim (Syndel; mixture of salmon GnRH analogue and dopamine receptor antagonist) at two doses (0.1 and 0.5 ml/kg body weight). Increases in milt and GtH induced by the high Ovaprim dose were significantly greater than those induced by 5 × 10−10 M 17,20β-P. Increases in milt, and packed sperm volume, and GtH induced by the lower Ovaprim dose were not significantly larger than those induced by 17,20β-P. The results suggest: (1) in common carp, 17,20β-P has a pheromonal role in milt production similar to that demonstrated in goldfish; (2) waterborne 17,20β-P might be a practical non-invasive technique for enhancing milt production in cultured common carp.

Sustained production of milt in rabbitfish, Siganus guttatus Bloch, by weekly injection of luteinizing hormone-releasing hormone analogue (LHRHa)

Mature male rabbitfish ( Siganus guttatus Bloch) received weekly injections of 200 μg of luteinizing hormone-releasing hormone analogue (D-Ala 6, Pro 9-LHRH-ethylamide) per kg body weight for 5 consecutive weeks. Mean spermatocrit, or packed sperm volume (27–51%), and mean sperm density (3.2–9.6×10 6 spermatozoa per kg body weight) decreased significantly 24 h after each injection. The amount of expressible milt (mean: 5.8–11.7 ml per kg) in response to weekly injections of LHRHa increased significantly relative to saline-injected fish (1.0–2.9 ml per kg), but only during the initial 4 weeks of regular hormone treatment. Three weekly injections of LHRHa likewise augmented mean sperm production (29.2–112.5×10 9 spermatozoa per kg) in rabbitfish. However, no significant enhancement in sperm production by LHRHa-injected fish was observed over the last 2 weeks of hormone injection. These results demonstrate that weekly injection of LHRHa can sustain milt production in mature rabbitfish, although their capacity to produce spermatozoa is limited to only 3 consecutive weeks of regular hormone treatment.

Spermiation response of mature rabbitfish, Siganus guttatus Bloch, to luteinizing hormonereleasing hormone analogue (LHRHa) injection

A method to quantify the spermiation response of mature rabbitfish to hormonal therapy is described. Spermatocrit or packed sperm volume was measured after milt loaded in non-heparinized microhematocrit capillary tubes was centrifuged for 45 min at 15 000 × g. Sperm density was estimated by a standard hemacytometer method. However, sperm density can be predicted from spermatocrit since their relationship is highly and positively correlated ( Y = 29.5 + 2.95 X r = 0.83; P < 0.01). Milt production by mature rabbitfish was highest (4.9 ml per kg body weight) at 24 h after injection of 20 μg of luteinizing hormone-releasing hormone analogue (D-Ala 6, Pro 9-LHRH-ethylamide) per kg body weight and coincided with iow spermatocrit (68%) and sperm density (14.1 × 10 6 spermatozoa per μl milt) levels. These results demonstrate that spermiation in mature rabbitfish can be reliably assessed by a spermatocrit method and that LHRHa can effectively stimulate spermiation in this species.

Heritability Estimates of Male Reproductive and Morphological Traits and Their Genetic Correlations with Female Egg Production and Other Related Traits in Chickens

Three unselected control strains and four strains selected for high egg production were studied. Semen weight (SW), packed sperm volume (PSV), and total sperm weight (TSW) were evaluated on two consecutive days. The female traits were age at first egg (AFE), hen-housed egg number (HHEN), hen-day rate of egg production (HDREP), egg weight (EW), and four egg-quality traits. Wattle and testes size were also measured in the males.Sire-plus-dam component heritabilities ± SE of SW, PSV, and TSW in the selected strains, were .36 ± .08, .42 ± .08 and .32 ± .06. The full sibling component heritabilities for the control strains were: .42 ± .15 for SW, .50 ± .15 for PSV, and .41 ± .15 for TSW. The heritabilities of wattle and testes weights computed by regression of son on father were: .54 ± .10 and .58 ± .11, respectively. The genetic correlations between semen and egg-production traits, estimated by intraclass and regression procedures were generally consistent in sign. The mean genetic correlations of SW, PSV, and TSW with EW were .23, .06 and .17, respectively. Semen traits were unfavorably correlated with HHEN (mean −.23, range −.60 to .04), HDREP (mean −.10, range −.36 to .14), and AFE (mean .27, range .03 to .40). Wattle size measured on 14-mo-old males was favorably correlated with HHEN (mean .36, range .26 to .55), HDREP (mean .23, range .05 to .44), and AFE (mean −.31, range −.17 to −.43). Semen traits as well as size of the testes and wattle appeared to be unrelated to egg-quality traits. Hence, wattle size, measured at an early age, could be useful in selecting for high egg production; and selection for semen production could increase egg size.

The Influence of Daylength, Body Weight, and Age on the Reproductive Ability of Broiler Breeder Cockerels

June-hatched broiler breeder cockerels of two strains were evaluated for reproductive performance in mating pens from 22 to 48 weeks of age. Two light programs with maximum daily daylengths of 15.5 or 16.5 hr were studied.An increase in the light day to 16.5 hr did not significantly affect the male reproductive traits except in number of completed matings and percent packed sperm volume (PSV). The males on 16.5 hr of light had significantly fewer completed matings than did the males on 15.5 hr. Strain 1 males on 16.5 hr produced significantly more spermatozoa at 35 and 40 weeks of age than males on 15.5 hr of light. Male body weights of both strains were significantly lower at 30 weeks of age on the longer daylength. Body weights of cockerels in all treatment groups increased with aging. The range in male body weight markedly influenced the percentage of producing cockerels with aging. During the late egg cycle, the number of producing males increased as body weight increased.The overall mean age of peak in the percentage of males in semen production was 44 weeks of age, which was 7 weeks later than peak egg production. Hatchability was significantly lower for male Strain 2, which had a higher percent PSV and a higher number of attempted matings than did Strain 1.Body weight was significantly correlated with male vent feather-wear at all ages and with the percentage of producing males at 48 weeks of age. The percentage of producing males was correlated with vent feather-wear, evert score, semen volume, and PSV.These results emphasize the importance of body weight selection for optimum breeding flock performance.

Selection for Egg Mass in the Domestic Fowl: 2. Packed Sperm Volume; Fertility and Hatchability Responses

A rapid genetic response was observed in male chickens selected for high packed-sperm volume (PSV) as a possible corollary to high egg mass in females. The PSV increased from 15% in the S0 generation to 22% in the S4 generation in two lines. Only minor changes were observed in the PSV of two nonselected lines during this same period. Realized heritability estimates for PSV, obtained by dividing the cumulative response by the cumulative selection differentials, were .48 and .44. Fertility levels in lines selected for high PSV were 20 to 25 percentage points lower than fertility levels in nonselected PSV lines in the S3 generation. Data indicated that selection for high PSV resulted in a decrease in the fertility levels of females mated to high PSV males. Although hatchability levels were lower in lines selected for high PSV than in nonselected lines, hatchability differences between lines were not significant.

Selection for Egg Mass in the Domestic Fowl: 1. Response to Selection

A study was conducted to measure selection response for daily egg mass from 154 to 294 days of age in four lines of White Leghorns and to determine the possibility of selecting males with high packed-sperm volume (PSV) as a corollary to egg mass. After three generations of selection, deviation of the selected lines from the control line in total egg mass per bird for 280 days of production varied from 1307 to 2173 g. Data failed to support the hypothesis that selection for PSV in males is associated with selection for increasing egg mass. Realized heritability for daily egg mass, obtained by dividing the cumulative corrected response by the cumulative selection differentials, ranged from .23 to .66 with a mean across lines of .42. Increases in egg mass equal or superior to those observed during the period of selection (154 to 294 days of age) were also observed during the second half of the test period (294 to 434 days).