scholarly journals Effect of Heat Stress on Buck’s Adaptability and Semen Characteristics

2016 ◽  
Vol 9 (1) ◽  
pp. 151-156 ◽  
Author(s):  
A Rahman ◽  
MM Hossain ◽  
M Khan ◽  
MT Kamal ◽  
MA Hashem
Keyword(s):  
Heat Stress ◽  
Semen Quality ◽  
Sperm Concentration ◽  
Sun Exposure ◽  
Biological Data ◽  
Measured Temperature ◽  
Semen Characteristics ◽  
Humidity Index ◽  
Severe Heat Stress

The experiment was conducted to investigate the effect of heat stress on adaptability and semen quality of buck. Almost similar 10 Black Bengal bucks were selected for the study at Artificial Insemination Centre, Bangladesh Agricultural University, Bangladesh. Prerequisite biological data were collected from each animal before keeping them sun heat and after 1 hour sun exposure. Different semen characteristics of each animal were measured. Temperature humidity index (THI) was 19.95 in the morning which indicate all the animals were in absence of heat stress and THI was 25.54 in the noon which indicate all the animals were in severe heat stress at noon. Buck 1 and buck 5 were more heat resistant (p<0.01), because their thermolysis capacity (TC) values were less than the others. There were no differences in tunica dartos index and semen characteristics among different bucks (p>0.05). Positive correlation between sperm motility and testis length (p<0.05), and negative correlation between sperm concentration and scrotal skin temperature (p<0.05) were found. From the study it can be concluded that all the bucks were in severe heat stress at noon time and TC can be used as an indicator for selection of buck for heat tolerance.J. Environ. Sci. & Natural Resources, 9(1): 151-156 2016

139 Heat stress has a deleterious effect on bull semen quality and subsequent embryo development

2020 ◽  
Vol 32 (2) ◽  
pp. 196
Author(s):  
A. Seifi-Jamadi ◽  
H. Kohram ◽  
M. Zhandi ◽  
N. Llamas Luceño ◽  
B. Leemans ◽  
...  
Keyword(s):  
Heat Stress ◽  
Ambient Temperature ◽  
Embryo Development ◽  
Semen Quality ◽  
Chromatin Condensation ◽  
Sperm Concentration ◽  
Cell Number ◽  
Cleavage Rate ◽  
Bull Semen ◽  
Humidity Index

High ambient temperature induces an increase in bovine body temperature above the physiological homeothermic point, leading to impaired reproductive performance. Belgian Blue bulls are more susceptible to heat stress compared with most other cattle breeds. Therefore, the aim of this study was to investigate whether high ambient temperature affected bull semen quality and subsequent embryo development. For this purpose, semen samples were collected from six Belgian Blue bulls during August (14-28 days after three consecutive warm days with temperature-humidity index between 63.8 and 83.7) and March 2016 (temperature-humidity index between 35.9 and 47.4). After semen collection, volume, sperm concentration, and motility of fresh semen were assessed. Furthermore, frozen sperm samples were used to assess the motion parameters and morphological abnormalities using computer-assisted sperm analysis, viability and reactive oxygen species (hydrogen peroxide and superoxide) production using flow cytometry, and acrosome integrity and chromatin condensation using fluorescence microscopy. Afterward, blastocysts were produced (r=4) by conventional invitro methods for assessment of embryo development (Wydooghe et al. 2014 Reprod. Fertil. Dev. 26, 717-724; https://doi.org/10.1071/RD13043). Cleavage rate was determined 48h after fertilisation, and the blastocyst rates were determined on Days 7 and 8 postinsemination. Moreover, Day 8 blastocysts underwent differential staining in order to determine the numbers of the inner cell mass, trophectoderm, total cell number, and apoptotic cells ratio. The data set was analysed using the GLM procedure of SAS (SAS Institute Inc.). Normal distribution was checked using the UNIVARIATE procedure, and the Shapiro-Wilk test and arcsine square root transformation were used when required. Furthermore, Duncan's test was applied to determine the significant differences (P=0.05). In fresh semen, samples from the non-heat-stressed (NHS) group showed a higher sperm concentration compared with samples from the heat-stressed (HS) group (P=0.05), whereas semen volume and motility were not affected by heat stress (P&gt;0.05). In frozen-thawed semen, total and progressive motility and straight-line velocity were lower in the HS group compared with the NHS group (P=0.05), whereas the generation of H2O2, percentages of aberrant chromatin condensation, total morphological abnormality, spermatozoa with bent tails, and distal protoplasmic droplets were higher in the HS group compared with the NHS group (P=0.05). The cleavage rate and blastocyst rates on Days 7 and 8 were higher (P=0.05) in the NHS group (70.4±1.13, 25.4±1.84, and 40.3±1.15, respectively) compared with the HS group (62.8±1.49, 15.4±1.56, and 23.3±1.84, respectively). However, there were no significant differences in hatched or hatching rate of two treatments (P&gt;0.05). The total cell number and trophectoderm were higher in NHS-derived blastocysts than in HS-derived blastocysts (P=0.05), whereas the apoptotic cells ratio was lower (P&lt;0.001) in NHS blastocysts (2.16±0.48% vs. 5.21±0.52%). In conclusion, these findings show that elevated ambient temperature during summer as a consequence of climate change can lead to decreased quality of fresh and frozen-thawed bull spermatozoa and subsequent embryo development.

scholarly journals Influence of heat stress on the quality of sperm production of boars-producers of different breeds and its fertilizing ability

2021 ◽  
pp. 106-114
Author(s):  
M. P. Gutman ◽  
N. N. Gorb ◽  
V. M. Sorokoletova
Keyword(s):  
Heat Stress ◽  
Semen Quality ◽  
Embryo Implantation ◽  
Sperm Concentration ◽  
The Body ◽  
Sperm Production ◽  
Large White ◽  
Study Results ◽  
Fertilizing Ability

The primary purpose of this work is to study the heat stress on the quality of sperm production in boars of different breeds (Large White, Landrace, Duroc, Maxgro). The authors found that heat stress affects the activity of pigs. The desire to reduce heat production leads to sedentary, passive animals, accompanied by decreased appetite, shortness of breath and inhibition of sexual reflexes in individuals. Against this background, the disturbances arising in the body, reinforced by a local increase in scrotal temperature, harm semen quality. The authors observed a tendency for decreased ejaculate volume and a decrease (statistically significant in most breeds) in the sperm concentration in the ejaculate by 11.47-34.96%. But at the same time, the organoleptic values (colour, consistency, smell) did not change. Heat stress hurts the fertility of pigs, reducing the probability of successful embryo implantation. The fertility of sow inseminated with semen from boars during heat stress decreased by 10.3-23.7%. And also, the fertility of the sow did not reach pre-stress levels until the end of the observation. Based on the study results, the authors found that, depending on the breed, pigs can tolerate heat stress in a more severe or milder form. The species Large White and Maxgro are less sensitive to increased ambient temperature (they had fewer changes in general condition, semen and fertility) than Duroc and Landrace pigs.

scholarly journals Comparison of semen characteristics between indigenous and Amo breeds cockerel of Gombe State, Nigeria

2019 ◽  
Vol 15 (2-1) ◽  
pp. 303-306
Author(s):  
Tijjani Haruna Usman ◽  
Saleh Mohammed Sir ◽  
Ma’aruf Bashir Sani
Keyword(s):  
Semen Quality ◽  
Sperm Concentration ◽  
Progressive Motility ◽  
Indigenous Breed ◽  
Normal Sperm ◽  
Abnormal Sperm ◽  
Significant Difference ◽  
Semen Characteristics ◽  
Genetically Improved ◽  
Abdominal Massage

The experiment was carried out to compare the semen characteristics of indigenous and Amo strains of cockerel at poultry unit of teaching and research farm of Federal University of Kashere, Gombe State, Nigeria. Semen samples were collected from nine indigenous and nine Amo breeds of cockerel at three days interval for two weeks using abdominal massage technique. Semen samples were examined macroscopically for semen colour, pH and ejaculation volume. Then, microscopic observation was carried for sperm concentration, mass motility, progressive motility, live and dead sperms percentage, normal and abnormal sperm, all for semen characteristics. The results showed a significant difference (P ≤ 0.05) between mass motility, progressive motility, sperm concentration and head defects of 4.85 ± 0.27 to 4.37 ± 0.19, 95.13 ± 0.43 to 81.63 ± 1.15%, 4.93 ± 1.84 to 3.40 ± 1.07×109/ml and 2.96 ± 0.17 to 3.44 ± 0.12% for indigenous and Amo breeds of cockerel, respectively. There were no significant differences observed as semen colour, ejaculate volume, semen pH, live / dead normal sperm neck (mid-piece), tail defects and sperm total abnormalities were found to be 2.85 ± 0.07 to 2.00 ± 0.090.21 ± 0.17 to 0.20 ± 0.02 /ml, 88.85 ± 0.58 to 72.70 ± 0.54% /ml, 11.14 ± 0.58 to 27.29 ± 0.54%, 81.00 ± 0.78 to 66.22 ± 0.61%,9.03 ± 0.42 to 13.96 ± 0.47%, 9.70 ±  to 13.00 ± 0.30 and 21.70 ± 0.59 to 30.40 ± 0.53% for the indigenous and Amo breed groups of cockerel, respectively. It was concluded that semen quality characteristics could be differed between genetically improved (Amo strain) and indigenous breed of cockerels.

Factors affecting the response of working boars to changing environmental temperature

1991 ◽  
Vol 1991 ◽  
pp. 140-140
Author(s):  
Angela H Cliff ◽  
J H Dunne ◽  
P R English ◽  
J S M Hutchinson ◽  
O Macpherson
Keyword(s):  
Heat Stress ◽  
Adverse Effects ◽  
Environmental Temperature ◽  
Semen Quality ◽  
Sperm Quality ◽  
Sperm Concentration ◽  
Factors Affecting ◽  
High Environmental Temperature ◽  
Sudden Rise ◽  
Sperm Output

It is well established that high environmental temperature can have adverse effects on sperm concentration and the normality of sperm in the boar. Induced abnormalities include reduced motility, abnormal heads, proximal droplets, coiled and bent tails and abnormal acrosomes (Malmgren and Larsson, 1989). While all stages of spermatogenesis can be adversely affected, the primary spermatocytes are most vulnerable to these influences. Since spermatogenesis occurs over 45 days, any adverse effects of elevated ambient temperature can affect sperm quality for around 6 weeks. The maximum period of infertility appears around weeks 3 and 4 after heat stress. Reduced levels of testosterone and sometimes of LH following heat stress are implicated in these adverse effects. There is evidence that boars subjected to high constant temperature (30°C), which have become acclimatised to such, are affected less in terms of sperm output and quality (Cameron and Blackshaw, 1980) than when boars are subject to sudden major increases in temperature from fairly low levels (15 to 30 C) e.g. during the summer months (Antonyuk et al, 1983). There also appears to be large differences between boars in their ability to adapt to exposure to high environmental temperature by minimising temperature rise and avoiding adverse effects on semen quality (Cameron and Blackshaw, 1980). These workers found that boars prone to heat stress show an acute rise in body temperature in response to elevated environmental temperature and this sudden rise has a more adverse effect on semen quality than the length of exposure to the elevated temperature. There appears to be little information available on the reasons for such important between boar differences. This study was carried out to determine rectal temperature responses of boars to varying summer temperature in an intensive pig enterprise in Scotland and to attempt to determine some of the factors associated with ‘high’ and ‘low’ responding boars.

Semen quality of Merino rams. 1. The effects of fleece length and season on semen quality

1965 ◽  
Vol 5 (18) ◽  
pp. 243
Author(s):  
DG Fowler
Keyword(s):  
Semen Quality ◽  
Control Group ◽  
Monthly Variation ◽  
Summer Period ◽  
High Quality ◽  
Semen Characteristics

One group of 11 medium wool Peppin Merino rams was kept in short wool during summer 1960-61 (treatment). A second group remained unshorn during this period (control). Semen was collected from all rams at 14-day intervals during the summer period, October 1960 until March 1961, and from control rams until 243 March 1962. Both groups of rams had semen of similar and high quality during summer 1960-61. In the control group there was significant monthly variation for all semen characteristics studied but semen quality remained generally high. Significant differences were found between individual rams for all semen characteristics studied, some rams having markedly degenerate semen during the summer periods.

23 Sperm quality of Pure Spanish stallions is affected by inbreeding coefficient and age

2020 ◽  
Vol 32 (2) ◽  
pp. 137
Author(s):  
Y. Pirosanto ◽  
M. Valera ◽  
A. Molina ◽  
J. Dorado ◽  
S. Demyda-Peyrás
Keyword(s):  
Sperm Motility ◽  
Inbreeding Depression ◽  
Negative Correlation ◽  
Semen Quality ◽  
Sperm Quality ◽  
Sperm Concentration ◽  
Inbreeding Coefficient ◽  
Semen Parameters ◽  
Computer Assisted

Inbreeding depression, a genetic condition produced by the mating of close-related individuals, has been associated with a reduction of fertility in several species. However, a loss in sperm quality was also associated with age. In horses, the few existing reports have described a tendency of both parameters to produce a negative effect on sperm quality. However, those reports were performed using a subjective evaluation of sperm motility. In the present study, a total of 692 ejaculates from 86 Pure Spanish stallions (PRE), aged between 3 and 22 years, were evaluated using a computer-assisted methodology to determine the effect of inbreeding in four semen parameters: free-gel volume (V), sperm concentration (C, by haemocytometer), and total (TM) and progressive (PM) sperm motility (by Spermvision sperm class analyser; Minitube). The inbreeding coefficient (F) was estimated using 300 000 PRE pedigree records approximately (minimum pedigree depth, eight equivalent complete generations; range, between 1 and 30.1%). Stallion, age, ejaculate, and season of semen collection were the variables included in the statistical model (general linear model), with ejaculate and season being the variables with a major effect (by variance components analysis). Our results showed that sperm concentration (r=−0.18; P&lt;0.0001) and volume (to a lesser extent) were reduced with advancing age, both showing a major decline after 15 years of age. To the contrary, sperm motility was not affected by age of the stallion. We also found a negative correlation between the inbreeding coefficient and ejaculate volume (r=−0.14; P&lt;0.001), with a marked decrease seen when F was between 7 and 20%. Also, a negative correlation was observed in PM (r=−0.08; P&lt;0.05), although to a lower extent. Conversely, C and TM were not affected by inbreeding depression (P&gt;0.05). In conclusion, our results demonstrated that high levels of inbreeding can compromise severely the sperm quality of the PRE stallion, which, subsequently, may have a negative influence on fertility. Ongoing studies using genomic data will help to detect genetic variants associated with stallion semen quality and how it is influenced by inbreeding in specific genomic regions.

scholarly journals Effect of Heat Stress on Behavior, Physiological and Blood Parameters of Goat

2013 ◽  
Vol 22 (1-2) ◽  
pp. 37-45 ◽  
Author(s):  
MM Alam ◽  
MA Hashem ◽  
MM Rahman ◽  
MM Hossain ◽  
MR Haque ◽  
...  
Keyword(s):  
Heat Stress ◽  
Heat Exposure ◽  
Blood Parameters ◽  
Experimental Animals ◽  
Treatment Groups ◽  
Exposure Temperature ◽  
Heat Treated ◽  
Significant Difference ◽  
Humidity Index ◽  
Severe Heat Stress

The research was conducted to study the effect of heat stress on behavior, some physiological and blood parameters with nine goats of almost similar in age, sex and weight into three groups. Three groups were divided as zero hour (T0), four hours (T4) and eight hours (T8) heat exposure. Temperature–humidity index (THI) value was calculated as 28.17 which indicate the experimental animals were in extreme severe heat stress. Skin and rectal temperature had no significant differences among the treatment groups but respiration/panting and pulse rate were increased with the increased of heat stress from T0 to T8 group (P<0.01).  Significant difference was found in standing time and lying time (P<0.01) in experimental groups. There were significant changes (P<0.01) in number of urination and defecation per hour but no significant changes was found in duration per urination in heat treated groups. The amount of RBC, PCV%, Hb%, WBC were increased with the increased of heat stress (P<0.01). Neutrophil, eosinophil, lymphocyte and monocyte numbers increased significantly (P<0.01) in heat treated groups.  It can be concluded that heat stress had significant changes on some behavioral, physiological and blood parameters of goat.DOI: http://dx.doi.org/10.3329/pa.v22i1-2.16465 Progress. Agric. 22(1 & 2): 37 - 45, 2011  

scholarly journals Effect of Selenium and Vitamin E Supplementation on Semen Quality in Dogs with Lowered Fertility

2015 ◽  
Vol 59 (1) ◽  
pp. 85-90 ◽  
Author(s):  
Anna Domosławska ◽  
Sławomir Zduńczyk ◽  
Wojciech Niżański ◽  
Andrzej Jurczak ◽  
Tomasz Janowski
Keyword(s):  
Vitamin E ◽  
Semen Quality ◽  
Sperm Count ◽  
Sperm Concentration ◽  
Control Group ◽  
Organic Selenium ◽  
Healthy Dogs ◽  
Manual Manipulation ◽  
Motility Parameters

Abstract Thirty clinically healthy dogs with poor semen quality were used in the study. Fifteen dogs were supplemented daily with selenium (0.6 mg/kg organic selenium from yeast) and vitamin E (5 mg/kg) per os for 60 d. The control group (15 dogs) was not supplemented. Semen was collected from all dogs by manual manipulation on days 0, 30, 60, and 90. The sperm concentration and motility parameters were evaluated with a Hamilton Thorne sperm analyser, version IVOS 12.3. For the assessment of sperm morphology, Diff-Quik stain was used. The percentage of live and dead spermatozoa was estimated on dried smears stained with eosin-nigrosin. The concentration of spermatozoa, most motility parameters determined (PMOT, VSL, VCL, ALH, BCF, RAPID, MEDIUM, SLOW, and STATIC), and the percentage of spermatozoa morphologically normal and live increased significantly (P < 0.05) after 60 d of supplementation. In the control group, there were no changes in motility parameters while the concentration and total sperm count decreased over the duration of the study. In conclusion, supplementation with selenium and vitamin E for 60 d can improve the quality of semen in dogs with lowered fertility.

scholarly journals Variation in body measurements and semen quality of Nigeria sheep breeds

2021 ◽  
Vol 48 (1) ◽  
pp. 55-61
Author(s):  
F. P. Agbaye ◽  
A. O. Sokunbi ◽  
M. A. Onigemo ◽  
O. Alaba ◽  
O. A. J. Anjola ◽  
...  
Keyword(s):  
Semen Quality ◽  
Sperm Concentration ◽  
Small Ruminants ◽  
Body Measurements ◽  
Morphometric Traits ◽  
Sheep Breeds ◽  
Scrotal Circumference ◽  
Body Weights ◽  
Qualité Du Sperme

small holder farmers enjoy in rearing small ruminants however, there are paucity of information on the morphometric traits and semen characteristics of Nigeria breeds of sheep in Ikorodu. Therefore, the effects of breeds on body measurements and semen quality of four sheep breeds in Nigeria were assessed. Twenty matured rams aged 2½ years and weighed 31.13±4.8 kg comprising five rams per breed namely: Balami (BAL), Ouda (UD), Yankasa (YAK) and West African Dwarf (WAD) were used for the study. Body measurements and semen quality of each ram was assessed for a period of six weeks after the four weeks of acclimatization. Live body weights (LBW), scrotal circumference (SC), height at wither (HtW), rump length (RpL) and rectal temperature (RT) were evaluated for body parameters. Semen samples were collected using electro-ejaculation method and evaluated for semen volume (SV), progressive sperm motility (PSM), sperm concentration (SC), normal sperm morphology (NSM), sperm livability (SL), and sperm acrosome integrity (SAI) using standard procedures. Results revealed that Yankasa had significantly (p<0.05) the higher live body weights (38.33kg) Live body weights while WAD recorded the least live body weights (28.50kg) live body weights which, was similar (p>0.05) with values recorded for Balami (28.67kg) and Ouda(29.0kg) breeds. Scrotal circumference was significantly (p<0.05) the lowest (24.50cm) in WAD but were similar (p>0.05) in Ouda (28.00cm), BAL (27.67cm) and YAK (26.33cm). The HtW showed similar trend with scrotal circumference. Meanwhile, there were no significant variation (p>0.05) in the value recorded for RpL (cm) and RT (0C). While, PSM, SAI and SV for all the breeds of sheep were statistically similar (p>0.05) in values and SC, SL and SNM were statistically different (p<0.05) between breeds.     La petite taille corporelle, la capacité de production élevée et les taux de croissance rapides des moutons sont des caractéristiques remarquables que les petits exploitants agricoles apprécient dans l'élevage de petits ruminants, cependant, il y a peu d'informations sur les traits morphométriques et les caractéristiques du sperme des races de moutons du Nigeria à Ikorodu. Par conséquent, les effets des races sur les mésures corporelles et la qualité du sperme de quatre races de moutons au Nigéria ont été évalués. Vingt béliers matures âgés de 2 ans et demi et pesant 31,13 ± 4,8 kg comprenant cinq béliers par race à savoir: Balami (BAL), Ouda (UD), Yankasa (YAK) et mouton nain de l'Afrique de l'Ouest (WAD) ont été utilisés pour l'étude. Les mesures corporelles et la qualité du sperme de chaque bélier ont été évaluées pendant une période de six semaines après les quatre semaines d'acclimatation. Les poids corporels vivants (LBW), la circonférence scrotale (SC), la hauteur au garrot (HtW), la longueur de la croupe (RpL) et la température rectale (RT) ont été évaluées pour les paramètres corporels. Des échantillons de sperme ont été collectés à l'aide de la méthode d'électro-éjaculation et évalués pour le volume de sperme (SV), la motilité progressive des spermatozoïdes (PSM), la concentration de spermatozoïdes (SC), la morphologie normale des spermatozoïdes (NSM), l'habitabilité des spermatozoïdes (SL) et l'intégrité des acrosomes du sperme (SAI) en utilisant des procédures standard. Les résultats ont révélé que Yankasa avait significativement (p <0,05) les poids corporels vivants les plus élevés (38,33 kg), tandis que WAD a enregistré les poids corporels vivants les moins élevés (28,50 kg) qui étaient similaires (p> 0,05) avec des valeurs enregistrées pour les races Balami (28,67 kg) et Ouda (29,0 kg). La circonférence scrotale était significativement (p <0,05) la plus basse (24,50 cm) dans le mouton nain de l'Afrique de l'Ouest mais était similaire (p> 0,05) chez Ouda (28,00 cm), BAL (27,67 cm) et YAK (26,33 cm). La hauteur au garrot (HtW) a montré une tendance similaire avec la circonférence scrotale. Pendant ce temps, il n'y avait pas de variation significative (p> 0,05) dans la valeur enregistrée pour la longueur de la croupe (RpL) (cm) et la température rectale (RT) (0C). Alors que PSM, SAI et SV pour toutes les races de moutons étaient statistiquement similaires (p> 0,05) en valeurs et SC, SL et SNM étaient statistiquement différents (p <0,05) entre les races.

scholarly journals Effect of genotype on semen quality traits of main and reciprocal crossbred chickens

2020 ◽  
Vol 46 (2) ◽  
pp. 32-39
Author(s):  
U. C. Isaac ◽  
U. H. Udoh ◽  
R. J. Nosike
Keyword(s):  
Reciprocal Cross ◽  
Semen Quality ◽  
Sperm Concentration ◽  
Genetic Constitution ◽  
Quality Traits ◽  
Breeding Method ◽  
Naked Neck ◽  
Significant Difference ◽  
Live Sperm

Semen quality of cocks is of utmost importance in reproduction. Breeding method, breed, strain and genetic constitution are the major components of the genetic factors capable of affecting the semen quality of cocks. This research seeks to determine the effect of genotype on the semen quality traits of 272 F crossbred cocks produced at day-old by main and 1 reciprocal crossbreeding of 69 Isa Brown and local frizzle feathered, naked neck and normal feathered chickens. The genotypes of the cocks were Isa Brow x frizzle feathered main cross (IBxF), Isa Brown x naked neck main cross (IBxNa), Isa Brown x normal feathered main cross (IBxN), frizzle feathered x Isa Brown reciprocal cross (FxIB), naked neck x Isa Brown reciprocal cross (NaxIB) and normal feathered x Isa Brown reciprocal cross (NxIB). At 36-40 weeks of age, semen was extracted from the cocks by abdominal  massage technique and used to evaluate semen volume (SV), sperm motility (SM), sperm concentration (SC) and live sperm (LS) at weekly intervals. Data obtained from the evaluation were subjected to analysisof variance and tested at 5% level of probability. Genotypes differed significantly (P <0.05) in SC at 37-40 weeks and in SM and LS at all ages. There was no significant difference (P>0.05) in SV. Regardless of genotype and age, the mean SV, SM, SC and LS ranged from 0.31±0.02 to 0.24±0.01ml, 71.84±1.33 to 58.75±2.16 %, 3.22±0.02 to2.92±0.02 x109/ml and 71.91±1.37 %, respectively. The NxIB and IBxNa genotypes produced largest numericalsemen volume at 37 and 39 weeks of age respectively. Whereas SC and LS were significantly highest for IBxF and IBxN respectively at week 37, SM was so for IBxN at all ages. Further, the LS of IBxN genotype was significantly highest at 36-38 and 40 weeks of age. The exotic Isa Brown and normal feathered main cross cocks exhibited the best semen quality traits among all genotypes studied and should be selected for improvement of the reproductive characteristics of cocks.  

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