S.K. Jindal

Effect of egg yolk levels and equilibration periods on freezability of Jamunapari buck semen

Semen ejaculates from adult Jamunapari bucks (2–4 year-old) maintained at the Central Institute for Research on Goats, Makhdoom (UP) were utilized for a study to find out the freezability of buck semen at different levels of egg yolk during different hours of equilibration period by conventional freezing protocol. The ejaculates were extended to maintain sperm concentration approximately 100 million per dose (0.25 ml) in Tris-Citric Acid- Fructose (TCF) diluent having 0, 5, 10, 15 and 20% (v/v) egg yolk and 6% (v/v) glycerol as a cryoprotectant. Filling and sealing of straws were done at 5oC in cold handling cabinet after 2, 3, 4 and 5 h of equilibration period followed by vapour freezing of straws for 10 min at 2 cm above the liquid nitrogen and finally plunged into liquid nitrogen. Post-thaw motility, live sperm count, sperm abnormalities, acrosomal integrity and hypo-osmotic swelling test were conducted to assess freezability. The post-thaw motility, live sperm count, abnormalities, acrosomal integrity and hypo-osmotic swelling (HOS) positive spermatozoa differed significantly (P<0.05) at different levels of egg yolk and equilibration periods. Our results indicated that 10% egg yolk and 4 h of equilibration period is the best combination for semen freezing. The overall results showed that the inclusion of egg yolk significantly improved sperm post-thaw motility, indicating its beneficial effects during the freezing steps of cryopreservation. Furthermore, neither glycerol nor egg yolk alone protected the acrosome and tail membrane; the combination of two significantly (P<0.05) reduced the proportion of acrosome-damaged spermatozoa.

Identification of heat stress-susceptible and -tolerant phenotypes in goats in semiarid tropics

The production performance of livestock is influenced by short-term variation in weather pattern. Goat adapts to varied ecological conditions and maintains productivity; however, wide variation has been observed among individual animals in response to environmental stimuli in a population. The objective of the present study was to identify the contrasting phenotypes on the basis of the physiological response in goats during heat stress. The study utilised 138 Jamunapari and 242 Barbari goats during peak heat-stress period and 82 Jamunapari and Barbari goats under thermo-neutral conditions. The physiological response of goats to different environmental conditions was evaluated by recording various parameters such as rectal temperature (RT), respiration rate (RR) and heart rate (HR). The temperature humidity index varied from 85.36 to 89.80 and from 65.32 to 73.12 during heat-stress and thermo-neutral assessments respectively. There was direct increase in HR and RR (>25%) due to heat stress in the animals, as compared with those in thermo-neutral conditions. On the basis of the distribution of RR and HR values across the breed in the population, the individuals having a RR of ≥50 and a HR of ≥130 are recognised as heat stress-susceptible phenotypes and those having a RR of ≤30 and a HR of ≤100 are recognised as heat stress-tolerant individuals. Different biomarkers were analysed in plasma, while heat-shock proteins and leptin were analysed in tissue extracts by ELISA. C-reactive protein and HSP90 concentrations were significantly (P < 0.05) different between heat stress-susceptible and heat stress-tolerant individuals. Heat-shock proteins HSP70, HSP 90, and C-reactive protein and triiodothyronine were reliable indicators of long-term heat stress. Identification of contrasting phenotypes in regard to heat stress is necessary so as to evaluate the expression pattern at a cellular level, as well as physiological and biochemical parameters.

Molecular expression of caprine estrogen receptor gene 1 in reproductive and non-reproductive tissues.

During the last decades, physiological effects of oestrogens have been increasingly explored by scientists and biotechnologists. Estrogens exert a wide range of effects on a large variety of cell types. Oestrogen and its receptors are essential for sexual development and reproduction. Estrogen receptor alpha is a nuclear receptor activated by the hormone oestrogen. In male, ERα is encoded by the gene estrogen receptor gene 1 (ESR1), responsible for better fertility. The ESR1 is involved in the reabsorption of luminal fluid during the transit of spermatozoa from the testis to the head of the epididymis which is important for their survival and maturation during epididymal storage. The absence of ESR1 leads to reduced epididymal sperm content, reduced sperm motility and fertilizing ability. Therefore, this is a good startby to study the expression pattern of estrogen receptor 1 gene in high-fertile (G1) and low-fertile (G2) bucks of Jamunapari and Barbari breeds identified on the basis of seminal quality traits and fertility trials. RNA was extracted from the tissues by TRIzol method. The identification and expression pattern of caprine ESR1 gene was analysed by real-time PCR (Roche LC-480). Our work shows that the relative quantification by RT-PCR indicates more fold in head of epididymis as compared to spleen of caprine ESR1 gene. Furthermore, the RT-PCR indicated that fertile bucks of Jamunapari breed have more fold value as compared to Barbari breed in respect of reproductive organ.

Effect of management system and season on semen freezability in Jakhrana bucks

Aim: The objective of the study was to determine the effect of the management system (intensive and semi-intensive) and season (autumn and winter) on semen freezability in Jakhrana bucks. Materials and Methods: A total of 24 Jakhrana bucks of same body weight and age (BW=30 kg, age=1 year) were randomly allotted into two groups, viz., Group I (intensive system, 12 bucks) and Group II (semi-intensive system, 12 bucks). These two groups were statistically tested for their homogeneity with respect to age and BW. Semen was collected twice weekly using an artificial vagina during two seasons: autumn (September-November) and winter (December-February). A total of 240 semen samples (120 from each group and season) were evaluated for post-thaw motility (PTM), viability, abnormality, functional membrane integrity (hypo-osmotic swelling [HOS]) response and acrosomal integrity. Results: The mean values of PTM and acrosomal integrity of spermatozoa were significantly (p<0.01) higher in Group II as compared to Group I. The mean values of viability and abnormality were also differed significant (p<0.05) between groups. However, the mean values of HOS response were found non-significant (p>0.05) between groups. The season showed a significant effect on all parameters except viability and HOS response. The PTM and acrosomal integrity of spermatozoa were significantly (p<0.01) higher in winter as compared to autumn season. Abnormality of spermatozoa was significantly (p<0.05) lower in winter season. Conclusions: This study indicates that both management system and season influence semen freezability. The semen collected from bucks reared under the semi-intensive system and winter season showed better semen freezability characteristics.

Effect of Management Systems on Seminal Characteristics of Jakhrana Bucks

A study was carried out with an objective to determine effect of management systems on seminal characteristics of Jakhrana bucks. Twenty-four Jakhrana bucks (one year-old with mean body weight of 30.0±2.0 kg) were randomly allotted into two groups as Gr-I (intensive system, n=12) and Gr-ll (semi-intensive system, n=12). A total of 336 ejaculates (168 from each group) were collected (twice weekly) using artificial vagina. Each ejaculate was evaluated for volume, mass motility, pH, progressive motility, sperm concentration, viability, hypo-osmotic swelling (HOS) response and acrosomal integrity. The mean semen volume was significantly (P<0.05) higher in Gr-I, but the sperm mass motility, initial progressive motility, sperm concentration, viability and acrosomal integrity were significantly (P<0.05) higher in Gr-ll. However, non-significant difference was observed in mean pH and HOS responsive spermatozoa. The study indicated that semi-intensive system of management is better for producing quality semen from Jakhrana bucks.

Zona free hamster ova penetration test: fertility indicator of buck spermatozoa

An experiment was conducted to assess the sperm fertility of Sirohi bucks. Ejaculates from three bucks were collected through artificial vagina and evaluated microscopically at 37° C. After final washing with Biggers-Whitten Whittingham (BWW) medium, semen was kept in a CO2 incubator for 20 min (swim up). The hamster oocytes were recovered following superovulation and visualized on the basis of cumulus cell mass. The oocytes were washed in BWW medium and then denuded with 0.1% hyaluronidase, the cumulus-free oocytes were treated with 0.1% protease for 2–3 min for zona lysis. Oocytes and swim up motile spermatozoa were co-incubated at 37° C for 3 h. in already incubated BWW drop (50 μl). At the end of co-incubation, washing of oocyte sperm complexes was done with BWW medium and then kept in hypotonic KCl solution (50 mg/ml), fixed in 2.5% glutaraldehyde for 10 min and stained with 0.1μg/ml DAPI (4,6-di amidino 2-phenyl indole). The number of sperms penetrated into the oocytes was determined. The result of the study indicated that among the three bucks, buck No. 1 had higher penetration rate (100%) as compared to buck No. 2 (93.00%) and buck No 3 (86.66%).

Development of parthenote following in vivo transfer of embryos in Capra hircus

The aim of this study is to generate parthenogenetic embryos from chemically activated in vitro matured caprine oocytes and to study the in vivo developmental potency of such embryos. The parthenogenetic embryos (2–8 and 16 cells to morula stage) were surgically transferred in 26 recipients. Pregnancy in recipients following embryo transfer was monitored by ultrasonography. The recipient aborted a foetus on day 34 post transfer. Sexing of parthenogenetic foetus showed a single band of amelogenin gene indicating female cell DNA. Microsatellite analysis revealed that the recipient has not contributed genetically to the parthenogenetic foetus confirming the identity of aborted foetus of parthenogenetic origin. The authors believe that this is the first authentic report on in vivo development of parthenogenetic foetus in Capra hircus.