Background and Objective: Goats are assuming a greater importance under small household system in India. Season affects the fertility of semen and thereafter is an important factor limiting the large scale application of artificial insemination with frozen semen. Limited literature underlying the correlation of climatic parameters with seminal quality. Hence, the present study was designed to find out the correlation of temperature (°C) and sunshine (h) on processed semen quality in Gaddi and Chegu goats. Materials and Methods: A total of 286 ejaculates (Gaddi, n = 106; Chegu, n = 180) were collected using artificial vagina and selected on basis of standard quality parameters. The ejaculates were extended in Tris citrate egg yolk extender containing 10% EY and 6% glycerol to maintain a concentration of 150×106 spermatozoa/straws. The representative straws from each ejaculates were thawed at 37°C for 30 sec, 24 h post incubation to compare seminal parameters between fresh and post thaw semen along with percent change due to the processing. Results: The data was analyzed using package R version 3.4.3. In Gaddi goats, HOST reactivity was negatively and significantly correlated (r = -0.471, r = -0.527, p<0.01) to temperature in both fresh diluted and post thaw semen. Whereas, temperature was negatively significantly correlated (r = -0.745, r = -0.768, p<0.01), with post thaw progressive motility and viability in Chegu goats. Conclusion: In conclusions, present study delineates temperature rather than sunshine (h) affecting semen quality in both Gaddi and Chegu bucks during breeding season.
PDF Abstract XML References Citation
How to cite this article
Goats are important livestock species of India. Gaddi and Chegu breeds of goats are the mainstay of a large portion of nomadic and hilly tribes of Himachal Pradesh (H.P.), India. Gaddi and Chegu goats are contributing towards income and employment generation, capital storage and improvement in household nutrition1. Chegu is pashmina yielding breed of goats found usually at altitude of more than 8000 feet above mean sea level in cold desert areas and produce valuable textile fibre pashmina hence called as “Pashmina goats”1. A progressively declining cattle population in H.P. accentuates goat rearing under small household system. Unabated decline in males of superior genetic merit due to rampant slaughtering and inadvertent breeding (inbreeding) underscores the importance to conserve superior males and their use for AI. Several socio-economic reasons along with lack of developmental policies for breed conservation and improvement leading to loss of breed utility and marginalization of goat population1, Chegu being worstly affected and therefore have been put under “Endangered species” (19th livestock census, 2012).
Goats, considered as seasonal breeder2, have been used for semen related studies during short days3,4, though out of season studies per se have also been undertaken5,6. Season affects the fertility of semen and thereafter is an important factor limiting the large scale application of artificial insemination with frozen semen7. Several studies across different geographical locations using different breeds of bucks have investigated effect of season on quality and cryosensitivity of semen5,6. Meagre studies available in literature underlying the correlation of climatic parameters with seminal quality. Hence, the present study was designed to find out the correlation of temperature (°C) and sunshine (h) on processed semen quality in Gaddi and Chegu goats.
MATERIALS AND METHODS
Study area: Study was conducted at University Livestock Farm of CSK Himachal Pradesh Krishi Vishvavidyalaya, Palampur (32.6°N, 76.3°E, altitude 1290.8 m) from September-December, 2017, January and March, 2018 and September-December, 2018, respectively.
Research procedure: The study was conducted on apparently healthy Gaddi bucks (n = 11, aged 2.16±0.36 years, weighing 39.1±2.82 kg), Chegu bucks (n = 8, aged 1.98±0.34 years, weighing 28.1±1.96 kg). These bucks were selected on basis of breeding history, breeding soundness evaluation and testicular diameters. All the bucks were maintained under identical conditions and were screened for diseases, Brucellosis8, Chlamydiosis9 to eliminate the possible transmission of infection.
Average light: dark h (h) and temperature (°C) during the period of study comprised the average of the values considered on the day of semen collection and the preceding days. The average light:dark h (h) and temperature (°C) ranged from 7.07±0.41:16.93±0.41 to 12.29±0.13: 11.71±0.13 and 9.88±0.51 to 21.94±0.18°C, respectively. Similar group of bucks from both the breeds were utilized for semen analysis during the period under study.
All bucks were subjected to grazing for 5 h and remained under confinement in a shed where they were fed as per the standards of Indian Council of Agricultural Research (ICAR)10. All males had round the clock access to the clean drinking water.
A total of 286 ejaculates (Gaddi, n = 106, Chegu, n = 180) from adult healthy bucks were collected using an estrus doe. The collections were made twice weekly in artificial vagina (AV) maintained at 42-43°C. The fresh ejaculates were evaluated for any gross abnormality including color as well as volume and concentration (Caprine Photometer, IMV 1409®) followed by microscopic examination for mass motility. The suitability of ejaculates for further processing was done using the standard criterion11. Absence of any gross abnormality, milky to creamy semen color, mass motility of >3 and initial progressive motility of >70% were the criteria for selection of semen. The post- thaw cryopreserved semen samples were evaluated for progressive motility12, viablility13, morphological abnormalities14 and HOST reactivity15. Percent change in the aforesaid parameters between freshand post-thaw semen was also calculated to determine the effect of cryopreservation.
The seminal plasma was removed as described previously16,17. The semen pellet thus obtained was extended with 2 equal fractions of tris citrate egg yolk extender, TEY (TRIS 1.21 g, Citric acid 0.685 g, D-fructose 0.5 g, benzyl penicillin 1000 IU mL1, streptomycin sulphate 1 mg mL1), EY (10%) and glycerol (6%). The TEY was added to semen at a gap of 2-3 min to yield a final concentration 150×106 spermatozoa/straw. The pH of the buffer was adjusted to 6.7-6.9.
Extended semen was filled in 0.25 mL French mini straws (IMV Technologies, L’Aigle, Cedex, France), by aspiration using micropipette (Minitube, Germany) and subsequently sealed at free end with the help of polyvinyl alcohol (PVA) (IMV Technologies, L’Aigle, Cedex, France) powder. All the aforementioned steps of semen handling were undertaken at controlled air temperature of 30°C. The straws were laid on a stainless steel rack and placed in cooling cabinet 4°C (Macro Scientific works Pvt. Ltd. India) for 4 h and thereafter exposed to liquid nitrogen vapors for 7 min. Finally the straws were plunged into liquid nitrogen for storage. The inventory of semen storage was also maintained. Thawing of semen straws was done at 37°C for 30 sec in a water bath18.
Proper ethical considerations related to animal handling and semen collections were observed and ensuring not to cause any injury during sampling.
Statistical analysis: The data obtained were analyzed using package19 R version 3.4.3. Multivariate analysis was used to determine correlations between climatic condition (Temperature (°C) and Sunshine (h) with the fresh and post-thaw semen quality parameters and to frame regression equations and their significance was tested again by using ANOVA. Results were presented as Mean±SEM and differences were considered significant when p<0.05.
RESULTS AND DISCUSSION
Correlations between the climatic conditions (Temperature (°C), sunshine (h)) and seminal parameters (progressive motility, live and dead, morphological abnormalities and HOST reactivity) are presented in Table 1. Amongst the progressive motility, viability, morphological abnormalities and HOST reactivity, it was only the HOST reactivity that was negatively and significantly correlated (r = -0.471, r = -0.527, p<0.01) to temperature in both fresh diluted and post thaw semen in Gaddi goats (Table 1). It can be inferred that with reduction in temperature there is improvement in HOST reactive sperms in Gaddi buck semen. Whereas, temperature was negatively significantly correlated (r = -0.745, r = -0.768, p<0.01), with post thaw progressive motility and viability in Chegu goats (Table 1) which suggests better post thaw semen quality during the winter months.
|Table 1: Inter-relationship between climatic conditions (Temperature (°C), sunshine (h)) and semen parameters in Gaddi and Chegu bucks|
|Relationship between parameters||Breed||Correlation coefficient||Regression estimate||Regression equation||p-value||Adjusted R2 value|
|PM fresh vs. temperature||Gaddi||0.0002||-||-||-||-|
|Chegu||-0.355||-0.286±0.17||y = 79.143-0.28x||0.12||0.077|
|LD fresh vs. temperature||Gaddi||-0.101||-0.107±0.17||y = 76.031-0.10x||0.53||0.015|
|Chegu||-0.270||-0.297±0.24||y = 79.805-0.29x||0.24||0.021|
|MA fresh vs. temperature||Gaddi||-0.232||-0.147±0.09||y = 10.137-0.14x||0.14||0.020|
|Chegu||0.088||0.029±0.07||y = 5.767+0.08x||0.70||0.047|
|HOST fresh vs. temperature||Gaddi||-0.471**||-0.880±0.26||y = 83.75-0.88x||0.002||0.200|
|Chegu||0.165||0.492±0.69||y = 53.939+0.49x||0.48||0.026|
|PM post thaw vs. temperature||Gaddi||0.141||0.190±0.22||y = 28.953+0.19x||0.38||0.005|
|Chegu||-0.745**||-0.870±0.18||y = 45.932-0.87x||0.000||0.531|
|LD post thaw vs. temperature||Gaddi||0.226||0.506±0.35||y = 35.410+0.56x||0.16||0.026|
|Chegu||-0.768**||-1.375±0.26||y = 66.925-1.37x||0.000||0.568|
|MA post thaw vs. temperature||Gaddi||-0.150||-0.112±0.12||y = 11.732-0.11x||0.35||-0.003|
|Chegu||0.116||0.038±0.07||y = 7.205+0.03x||0.62||0.041|
|HOST post thaw vs. temperature||Gaddi||-0.527**||-1.362±0.35||y = 70.310-1.36x||0.000||0.259|
|Chegu||-0.362||-0.678±0.41||y = 48.925-0.67x||0.11||0.082|
|PM fresh diluted vs. light hours||Gaddi||-0.198||-0.281±0.22||y = 75.569-0.28x||0.21||0.014|
|Chegu||0.044||0.064±0.34||y = 73.490+0.06x||0.85||0.053|
|LD fresh diluted vs. light hours||Gaddi||-0.040||-0.077±0.31||y = 75.061-0.07x||0.80||0.024|
|Chegu||-0.139||-0.280±0.46||y = 76.657-0.28x||0.55||0.034|
|MA fresh diluted vs. light hours||Gaddi||0.253||0.288±0.17||y = 5.701+0.28x||0.11||0.039|
|Chegu||-0.222||-0.134±0.17||y = 7.361-0.13x||0.34||0.003|
|HOST fresh diluted vs. light hours||Gaddi||-0.055||-0.187±0.54||y = 72.276-0.18||0.73||0.023|
|Chegu||-0.018||-0.098±1.27||y = 63.578-0.09x||0.93||0.055|
|PM post thaw vs. light hours||Gaddi||0.106||0.265±0.40||y = 29.72+0.26x||0.51||0.014|
|LD post thaw vs. light hours||Gaddi||0.272||1.097±0.62||y = 34.19+1.09x||0.08||0.049|
|Chegu||0.110||0.360±0.76||y = 39.308+0.36x||0.64||0.042|
|MA post thaw vs. light hours||Gaddi||0.012||0.016±0.21||y = 9.945+0.01x||0.94||0.026|
|Chegu||-0.223||-0.134±0.13||y = 8.961-0.13x||0.34||0.002|
|HOST post thaw vs. light hours||Gaddi||-0.251||-1.166±0.72||y = 59.509-1.16x||0.11||0.030|
|Chegu||0.362||1.237±0.75||y = 26.952+1.23x||0.11||0.082|
PM: Progressive motility, LD: Viability, MA: Morphological abnormalities, HOST: Hypo osmotic swelling test, **Values with different superscripts within same row differs (p<0.01)
Present study evaluated relationship of fresh diluted and post thaw semen parameters to change in climatic conditions within the short days of breeding season, which however is not available in the literature. Irrespective of the lack of literature for direct comparison, the present study delineates temperature rather than sunshine (h) affects semen quality. During low temperature of breeding season there was an improvement in HOST reactivity in fresh and post thaw semen in Gaddi bucks. Similarly, during a period of low temperature the post thaw progressive motility and viability were higher in Chegu buck semen. Murase and coworkers reported that post thaw motility was significantly higher in winters while HOST reactivity did not differ between season20. Moreover the relation to temperature to post thaw betterment of motility and viability in Chegu bucks could also be due to the reason that Chegu goat is native of temperate reason and may therefore perform better under low temperature.
Spring and summer have been generally accepted by various researchers’ to reduce the seminal quality with increased percentage of dead and abnormal sperms along with reduced motility21-22. Extreme temperature affects the function of the epididymis, alters the semen pH towards alkalinity23 and increases the percentages of abnormal and dead sperms24 and could also lead to testicular degeneration and even complete sterility23,24.
On the other hand, the aforesaid trend on semen quality revealed, autumn to be the best season resulting in better motility, viability and morphology of sperms, along with enhanced ability to withstand cryo-injuries25,26. Kumar and coworkers observed better ability of sperms to withstand freezing and thawing during autumn than winter27.
Winters have been equivocal in affecting the semen quality. Researchers observed better semen quality during winters5. Similarly, Gallego-Calvo6 and coworkers reported increased post thaw quality but reduced percentage of motile sperms during winter. Other studies corroborated winter to favour semen quality28,29. Reduced percent of dead sperms were observed during winters24,26. Researchers observed no effect on seasonal variability on HOST reactivity, while the post thaw motility, acrosomal integrity and abnormalities were severely affected in autumn compared to winter20. To the contrary, the desired semen quality could not be achieved in winters30,31.
Delgadillo and coworkers suggested photoperiod as main factor responsible for seasonality in buck reproductive activity. Short days and decreasing day length stimulate the secretion of luteinizing hormone (LH), which intern, induces testicular growth and the release of testosterone, resulting in quantitative and qualitative improvements in semen production along with increased sexual behavior32. Contrastingly, long days and increasing day length reduce LH secretions and testicular growth, leading to a fall in the plasma testosterone concentrations, reduced sperm quality and diminished sexual behavior21,22.
However other workers also propose that it is not only photoperiod that solely regulates but several other factors which may also influence semen. Hence there is a consensus among researchers interested in breeding of goats, that the quality of bucks’ semen is affected by various factors including but not limited to breed3, season6,26,30,32,33 and source of protein supplemented in ration34. Whereas, another group of researchers argued that season effects on semen quality were minor and the semen quality remained in the range of good semen in all seasons35. Some studies have shown that the sperm motility of pubertal bucks was high in autumn and low in summer season24.
In addition to effect of photoperiods on the LH release as listed wide supra, a favorable season for semen production could be attributed to changes in total protein and protein composition of seminal plasma36. Seminal plasma protein may influence seasonal resistance of the spermatozoa to freeze thaw damage. Smith and coworkers recorded higher total protein concentration of seminal plasma (36.9 vs. 23.0 mg mL1) during breeding than non-breeding season suggesting its role in protection against cryopreservation effects36. Researchers observed that sperm samples supplemented with proteins from the buck seminal plasma obtained during non-breeding season led to deterioration of sperm quality37, while other studies have demonstrated the positive effects on sperm quality after thawing when the semen was supplemented with proteins or seminal plasma collected during breeding season38. There were alterations in total protein composition of seminal plasma that influenced seasonal resistance of semen to freeze thaw process.
It was concluded that temperature rather than sunshine (h) is the main factor affecting the seminal quality parameters in both Gaddi and Chegu breed of goat during breeding season.
This study discovered the correlation of climatic parameters with seminal quality in Gaddi and Chegu goats of Himachal Pradesh, India. In Gaddi goats, HOST reactivity was negatively and significantly correlated to temperature in both fresh diluted and post thaw semen. Whereas, temperature was negatively significantly correlated with post thaw progressive motility and viability in Chegu goats. In brief, study suggests temperature as the main factor affecting the seminal quality parameters in both Gaddi and Chegu breed of goat during breeding season. The study will help the researchers to uncover the relationship of climatic factors with seminal quality in different breeds reared in different geographical locations and strengthen our finding of impact of temperature rather than sunshine (h) on the seminal parameters in goats.
Authors are grateful to Dr Madhumeet Singh (Professor and Head, Department of Vety. Gynae.), Dr. Mandeep Sharma (Dean, College of Veterinary and Animal Sciences) CSKHPHV, Palampur for technical and administrative support and Department of Dairy and Fisheries, GOI for financial assistance under project Adhoc-Misc 2127-37 for carrying out this study.
- Fatet, A., M.T. Pellicer-Rubio and B. Leboeuf, 2010. Reproductive cycle of goats. Anim. Reprod. Sci., 124: 211-219.
- Purdy, P.H., 2006. A review on goat sperm cryopreservation. Small Rumin. Res., 63: 215-225.
- Gangwar, C., S.D. Kharche, S. Kumar and S.K. Jindal, 2016. Cryopreservation of goat semen: Status and prospects. Indian J. Small Rumin., 22: 1-10.
- Farshad, A., A. Yousefi, A. Moghaddam and B. Khalili, 2012. Seasonal changes in serum testosterone, LDH concentration and semen characteristics in Markhoz goats. Asian-Aust. J. Anim. Sci., 25: 189-193.
- Gallego-Calvo, L., M.C. Gatica, J. Santiago-Moreno, J.L. Guzmán and L. Zarazaga, 2015. Seasonal changes in reproductive activity, sperm variables and sperm freezability in Blanca Andaluza bucks. Spanish J. Agric. Res., Vol. 13.
- Chahota, R., S. Gupta, B. Bhardwaj, P. Malik, S. Verma and M. Sharma, 2015. Seroprevalence studies on animal Chlamydiosis amongst ruminants in five states of india. Vet. World, 8: 72-75.
- Rather, H.A., R. Islam, A.A. Malik and F.A. Lone, 2016. Addition of antioxidants improves quality of ram spermatozoa during preservation at 4°C. Small Rumin. Res., 141: 24-28.
- Hancock, J.L., 1951. A staining technique for the study of temperature-shock in semen. Nature, 167: 323-324.
- Sariozkan, S., M.N. Bucak, P.B. Tuncer, U. Tasdemir, H. Kinet and P.A. Ulutas, 2010. Effects of different extenders and centrifugation/washing on postthaw microscopic-oxidative stress parameters and fertilizing ability of Angora buck sperm. Theriogenology, 73: 316-323.
- Murase, T., N. Imaeda, H. Yamada and K. Miyazawa, 2007. Seasonal changes in semen characteristics, composition of seminal plasma and frequency of acrosome reaction induced by calcium and calcium ionophore A23187 in large white boars. J. Reprod. Dev., Vol. 53.
- Delgadillo, J.A. and P. Chemineau, 1992. Abolition of the seasonal release of luteinizing hormone and testosterone in Alpine male goats (Capra hircus) by short photoperiodic cycles. Reproduction, 94: 45-55.
- Zarazaga, L.A., J.L. Guzmán, C. Domínguez, M.C. Pérez and R. Prieto, 2009. Effects of season and feeding level on reproductive activity and semen quality in Payoya buck goats. Theriogenology, 71: 1316-1325.
- Salah, M.S., F.D. El-Nouty, M.R. Al-Hajri and H.H. Mogawer, 1992. Effect of season on seminal characteristics of Holstein bull under semi-arid environment I. Biophysical characteristics. Asian-Aust. J. Anim. Sci., 5: 439-447.
- Ahmad, N. and D.E. Noakes, 1996. Seasonal variations in the semen quality of young British goats. Br. Vet. J., 152: 225-236.
- Karagiannidis, A., S. Varsakeli and G. Karatzas, 2000. Characteristics and seasonal variations in the semen of Alpine, Saanen and Damascus goat bucks born and raised in Greece. Theriogenology, 53: 1285-1293.
- Kumar, N., B. Rai, S.A. Bhat, S.D. Kharche, C. Gangwar, S.K. Jindal and S. Chandra, 2016. Effect of management system and season on semen freezability in Jakhrana bucks. Vet. World, 9: 199-202.
- Coloma, M.A., A. Toledano-Díaz, C. Castaño, R. Velázquez, A. Gómez-Brunet, A. López-Sebastián and J. Santiago-Moreno, 2011. Seasonal variation in reproductive physiological status in the Iberian ibex (Capra pyrenaica) and its relationship with sperm freezability. Theriogenology, 76: 1695-1705.
- Jiménez-Rabadán, P., M. Ramón, O. García-Álvarez, A. Maroto-Morales and E. Del Olmo et al., 2012. Effect of semen collection method (artificial vagina vs. electroejaculation), extender and centrifugation on post-thaw sperm quality of Blanca-Celtibérica buck ejaculates. Anim. Reprod. Sci., 132: 88-95.
- Barkawi, A.H., E.H. Elsayed, G. Ashour and E. Shehata, 2006. Seasonal changes in semen characteristics, hormonal profiles and testicular activity in Zaraibi goats. Small Rumin. Res., 66: 209-213.
- Wang, W., J. Luo, S. Sun, L. Xi and Q. Gao et al., 2015. The effect of season on spermatozoa motility, plasma membrane and acrosome integrity in fresh and frozen-thawed semen from Xinong Saanen bucks. Reprod. Domest. Anim., 50: 23-28.
- Delgadillo, J., B. Lebœuf and P. Chemineau, 1993. Maintenance of sperm production in bucks during a third year of short photoperiodic cycles. Reprod. Nutr. Dev., 33: 609-617.
- Qureshi, M.S., D. Khan, A. Mushtaq and S.S. Afridi, 2013. Effect of extenders, postdilution intervals and seasons on semen quality in dairy goats. Turk. J. Vet. Anim. Sci., 37: 147-152.
- Elhammali, N.S. and A.S. Elsheikh, 2014. Pubertal traits of male goats kept on rations supplemented with different protein types. IOSR-J. Agric. Vet. Sci., 7: 18-21.
- Gubartallah, K.A., M.A. Abdallah, A.O. Bakhiet and O.A. El-Khider, 2004. Some observations on the reproductive performance of sudanese nubian bucks. Sud. J. Vet. Sci. Anim. Husb., 43: 217-222.
- Leahy, T., G. Evans, W.M.C. Maxwell and J.I. Marti, 2010. Seminal plasma proteins do not consistently improve fertility after cervical insemination of ewes with non-sorted or sex-sorted frozen-thawed ram spermatozoa. Reprod. Fertil. Dev., 22: 606-612.
- La Falci, V.S.N., H. Tortorella, J.L. Rodrigues and A. Brandelli, 2002. Seasonal variation of goat seminal plasma proteins. Theriogenology, 57: 1035-1048.