Ranjana Sinha

Sperm DNA damage causes, assessment and relationship with fertility: A review

Evaluation of sperm quality has been mainly based on subjective parameters included in the spermiogram. Results of these parameters have been correlated with fertility but this relationship is not always true. Recently, for bull fertility assessment, sperm DNA integrity assessment has been proposed as an important index. Sperm DNA integrity has got an important role in success of fertilization process and fetal and offspring development. DNA integrity assessment has got a pivotal role in assisted reproductive techniques such as in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), besides sperm quality assessment and putative fertility predictor. Various techniques for assessment of sperm DNA integrity have been proposed. Using various sperm DNA integrity assays for detection and characterization of DNA fragmentation will aid in improving semen storage procedures by identification of various protocols which are less likely to be associated with DNA damage. Moreover, sperm DNA assays may help in screening bulls that produce good freezable semen with reasonable fertility.

Effect of Varying Osmolarity of Tris Extender on Seminal Attributes of Buffalo during Refrigeration

The aim of the present study was designed to investigate the effect of varying osmolarity of tris egg yolk citrate glycerol extender on seminal attributes of buffalo at various hours of refrigeration at 5 ÂoC. Twenty four ejaculates having mass motility ≥ 3+ from 4 bulls (6 ejaculate from each bull) were collected. Each ejaculate was divided into four group’s viz., Group I, Group II, Group III and Group IV, diluted with extenders with osmolarities of 240, 260, 280 and 300, milliosmol/kg, respectively, upto 80A—106 sperm/ml. After, dilution, semen samples were filled in French mini straws and kept at 5°C and evaluated at 0, 24, 48, and 72, hours for various seminal attributes such as individual motility, viability, acrosomal integrity, and hypo-osmotic swelling test. No significant difference in individual motility at 0 hour was observed among all the groups. However, at 24, 48 and 72 hours, the individual motility was significantly (P

PCR-RFLP Analysis of TNP2 Gene in Indigenous Cattle Breeds

One of the key factor for successful execution of breeding programs is the availability of best male which are selected from the existing germplasm because male have greater role in genetic improvement and up-gradation. Increasing reliability on artificial insemination (AI) techniques, for rapid and maximum genetic improvement, outstanding breeding bulls are utilized intensely. To meet the requirement of genetically superior bull and good quality frozen semen in India, a Minimum Standard Protocol (MSP) for semen production was developed to produce frozen semen of uniform quality (DAHD&F, 201617). However, some of the worthy males have low fertility even having standard semen parameter. Among the several reasons of infertility and sub-fertility, maturation of spermatozoa is an important factor (Foresta et al., 1992). Therefore, Genes affecting the spermatogenesis and spermatogenesis are crucial for efficient utilization of resources, maximizing production and genetic improvements. Molecular defects in these Present study was conducted on 50 bulls and 40 male calves of Sahiwal, Tharparkar and Karan Fries cattle maintained at Artificial Breeding Research Center and Livestock Research Center, NDRI Karnal (Haryana) to identify genetic polymorphisms in TNP2 gene. A total of 1528 bp of TNP-2 gene were studied in Bos indicus cattle breeds, which are widely distributed in Indian sub-continent. Three sets of primers for TNP2 gene on the basis of Bos Taurus sequence (Acc. NoBK_006514) were designed using Primer3 software and PCR products of 459, 483, 484 base pairs were obtained. Amplicons were custom sequenced and subjected to Clustal W analysis which showed nucleotide changes in non coding region in Indian cattle breeds as compared to Bos taurus. Analysis of SNPs were performed, using restriction fragment length polymorphism (PCR-RFLP), to detect nucleotide changes in the sequence as reported (g. 480 C>T and g. 1536 C>T) in Chinese Holstein breed. Polymorphism at 480 C>T was present while for g. 1536 C>T, there were absence of variability in the sampled population of Sahiwal, Tharparkar and Karan Fries cattle. K e y w o r d s

Role of preputial washing in reducing microbial load and improving bovine semen quality

Quality semen production remains the main focus and objective of semen processing laboratories throughout the world. Bacterial and other microbial contaminants affect the semen quality and hence the fertility, and also lead to reproductive disorders as well as lower conception rates and increased embryonic mortality, abortion and other complications in females. Microbial contamination affects the semen adversely, by exerting direct spermicidal effect, formation of reactive oxygen species, toxin production, adherence with spermatozoa, deriving nutrients and oxygen from the medium and thus competing with spermatozoa for the factors of growth and normal functioning. Despite hygienic measures, several ubiquitous and opportunistic microbes find their ways into semen during collection, processing, and storage of semen, and survive even during freezing. Stringent sanitary precautions are therefore required at every step of collecting semen and its processing. Preputial cavity is considered as main source of semen contaminating microorganisms. Flushing the preputial cavity with normal saline or any suitable liquid combination with antimicrobial activity, prior to semen collection reduces the microbial load and thereby improves the semen quality.

Sperm dosage and site of insemination in relation to fertility in bovines

Low sperm numbers in artificial insemination (AI)-doses are being used widely to make the best use of high genetic value bulls as well as sex-sorted semen. Sperm concentration needed for AI to obtain reasonable fertility, taking genetic value of bull and numerous others components into consideration is one of the essential constituents for successful AI breeding program. However, low sperm concentrations in AI-doses lead to reducing post-thaw viability. The reduction in viability of low sperm doses may be affected by fresh semen volume, sperm number and seminal plasma level at final dilution. Reduction in quality and fertility of low sperm doses is one of the limitations for their use in successful AI programme. Sperm number per AI required to achieve optimum fertility is one of the main crucial things to AI industry, and numerous efforts have been made in this regard. Due to great variability among bulls, sperm number per AI could be a limiting factor in achieving acceptable fertility values. Fertility of low sperm doses may vary among bulls, and non-return rates (NRRs) with low sperm doses may be determined by fertility level of bull. On the basis of individual bulls, sperm numbers in AI doses needed to be adjusted to reduce the variations in NRRs among bulls. Utilizing high fertile bulls for low sperm doses with acceptable non-return rates (NRRs) may be a way to cover a large number of bovines under AI in countries like India. Deposition site within the uterine horn may alter non return rates following inseminations with low sperm doses. Following deep-uterine inseminations, acceptable pregnancies may be achieved with low sperm doses and even if ovulation side is unknown.