M. Bhakat

Influence of Vitamin E, Macro and Micro Minerals on Reproductive Performance of Cattle and Buffalo - A Review

Most of the periparturient disorders in dairy cattle and buffaloes have been associated with vitamin and mineral deficiencies. Thus supplementation during periparturient period wherein there is heavy demand and drain of nutrients could probably prevent these disorders. Further these problems need to be addressed in light of the region specific requirements.

Incubation of spermatozoa with Anandamide prior to cryopreservation reduces cryocapacitation and improves post-thaw sperm quality in the water buffalo ( Bubalus bubalis )

Anandamide (AEA), an endocannabinoid, has been shown to reduce capacitation and acrosomal exocytosis in human spermatozoa. Because buffalo spermatozoa are highly susceptible to cryopreservation induced damage, AEA was assessed as to whether it could protect spermatozoa from cryo-damage. Six ejaculates from six Murrah buffalo bulls (total 36 ejaculates) were utilized for the study. Each ejaculate was divided into four aliquots; spermatozoa in Aliquot 1 were extended in Tris-Citrate-Egg Yolk and frozen as per the standard protocol. Spermatozoa in Aliquots 2, 3 and 4 were incubated with AEA at 1 nM, 1 μM and 10 μM, respectively in Tris-Citrate extender for 15 min at 37 °C before cryopreservation. Cryopreserved spermatozoa were thawed at 37 °C for 30 s before assessment of sperm motility, membrane integrity, capacitation, acrosome reaction, mitochondrial membrane potential (MMP) and lipid peroxidation status. The proportion of motile and membrane intact spermatozoa were greater (P < 0.05) with use of 1 μM AEA incorporated group compared with other groups. The proportion of un-capacitated and acrosome intact spermatozoa was greater (P < 0.05) with use of 1 or 10 μM of AEA compared with the other groups. When compared to the control group, use of 1 μM AEA resulted in a greater proportion of spermatozoa with high MMP (P < 0.05). There was no significant difference in the lipid peroxidation status of spermatozoa among any of the four groups. It was inferred that the protective role of AEA during cryopreservation of buffalo spermatozoa was dose dependent and incubation of spermatozoa with AEA at 1 μM concentration prior to cryopreservation reduced cryo-capacitation and improved post-thaw sperm quality in buffalo.

Effect of preputial washing on bacterial load and preservability of semen in Murrah buffalo bulls

Aim: To study the effect of preputial washing on bacterial load, preservability and semen quality in Murrah buffalo bulls Materials and Methods: A total of 36 collections of three Murrah buffalo bulls maintained at Artificial Breeding Research Centre, ICAR-National Dairy Research Institute, Karnal, were collected at weekly intervals from each bull without preputial washing and latter ejaculates from same bull with preputial washing by infusing normal saline (0.85%), KMnO4 (0.02%) and savlon (2.0%) to first, second and third bull, respectively. The microbial load and semen quality were evaluated during different hours of storage at refrigerated temperature (0, 24 and 48 h) and after thrawing of cryopreserved (at −196°C) semen. Results: The results of preservation of semen at refrigerated temperature showed that bacterial load was markedly lower in ejaculates of bulls subjected to preputial washing. Semen preserved at refrigerator temperature and cryopreserved, the effect of washing solution was significant for individual motility (IM), non-eosiniphilic count, hypo-osmotic swelling reactivity (HOST), total plate count (TPC) and acrosome integrity. KMnO4 was found to be the best in lowering bacterial load, sperm abnormalities and in improving semen quality such as motility, non-eosinophilic count, HOST and acrosome integrity even up to 48 h of preservation and cryopreserved semen. Effect of duration of preservation and stage of cryopreservation was also significant for IM, non-eosiniphilic count, HOST, sperm abnormalities and acrosome integrity. Conclusion: Overall the results suggested that preputial washing with KMnO4 solution improved the semen quality and reduced microbial load of Murrah buffalo bull’s semen preserved at refrigerated temperature and cryopreservation.

Disposal rate in different age groups of Karan Fries (Crossbred) males in organized herd.

Aim: The present study was carried out to analyze the disposal rate in different age groups of Karan Fries (KF) males in National Dairy Research Institute herd. Materials and Methods: Records on 1740 KF crossbred bulls born during the period 1997-2012 were collected with an objective to ascertain the effect of genetic and non-genetic (Period of birth and season of birth) factors on the disposal pattern of KF males. The percent of animals disposed from the herd due to mortality and culling was calculated by proportion using descriptive statistics. The data were subjected to Chi-square test to test the difference due to different factors. Results: Overall disposal rate for the different age groups of 0-1 m, 1-2 m, 2-3 m, 3-6 m, 6-18 m, 18 m-3 year and 3-5 year were calculated as 17.9, 16.3, 14.2, 25.8, 49.0, 37.6 and 51.65%, respectively. In the age groups, 3-6 m, 6-18 m and 3-5 year, effect of periods of birth were found to be statistically significant (p<0.01) for overall disposal rate. Across different seasons of birth, overall disposal rates differed significantly (p<0.01) in different age group except in 3-5 year age group. Differences in overall disposal rate due to genetic group were statistically significant (p<0.01) in 1-2 m, 2-3 m, 3-6 m, 6-18 m, 18-3 year and 3-5 year age groups. Conclusion: Overview of the results indicated that higher overall disposal rate in age group of 1 month was due to mortality while, in the age groups of >1 month, culling was the primary cause.

Temporal changes in pregnancy-associated glycoproteins across different stages of gestation in the Barbari goat

The objective of this study was to characterize the temporal profile of pregnancy-associated glycoproteins (PAGs; isoforms 1-11) across different stages of gestation in the Barbari goat. Placentae were collected from local abattoir, classified according to crown rump length of the corresponding foetus into five groups (0-30, 31-60, 61-90, 91-120, and 121-150 days of gestation), and used for relative quantification of mRNA expression by Pfaffl method. In addition, adult female goats (pregnant, n = 7; non-pregnant, n = 5) were used to estimate weekly plasma PAG and progesterone (P4) concentrations. The relative mRNA expression of PAGs was greater (p<0.05) during 31-60 days of gestation, which correlated well with the temporal changes in plasma PAG concentrations. Relative expression of PAGs decreased steadily as gestation advanced with minimum expression observed just before parturition, except for PAG-4 and PAG-8 that showed constantly higher expression throughout pregnancy. Plasma PAG and P4 concentrations showed a distinct temporal pattern with a significant increase beginning at 2 weeks and return to basal levels by 20 weeks of gestation. However, PAG concentrations reached a peak earlier in gestation (8 weeks) than P4 (10-14 weeks). Correlation analysis indicated a strong positive association (r = 0.748, p<0.01) between plasma PAG and P4 concentrations. In conclusion, results of this study indicate a distinct temporal pattern of PAG expression and secretion during gestation in the Barbari goat. The temporal changes in PAGs and the positive association with P4 are suggestive of their role in maintenance of pregnancy and progressive foetal development.

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

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.

Improvement in sperm functional competence through modified low-dose packaging in French mini straws of bull semen

To achieve the targeted artificial insemination coverage with the current rate of semen production, without affecting the conception rate, it needs to reduce the number of spermatozoa per insemination dose in India as per international practice. Therefore, this study was planned to perform different levels of semen dilution, compare in vitro post‐thaw semen quality and develop a modified low‐dose semen packaging method in French mini straw to minimise semen dilution effect. Sixteen ejaculates were collected from Karan Fries bulls (n = 4). The mean percentage post‐thaw motility, viability, membrane integrity, acrosome integrity, lipid peroxidation and capacitation status were estimated as post‐thaw sperm function assays in semen sample diluted to 20, 15, 10 and 5 million spermatozoa per 0.25 ml and filled in the French mini straw by conventional packaging. No significant (p > .05) difference in post‐thaw sperm quality was observed between 15 and 20 million doses; however, below 15 million sperm quality get reduced. There was no significant difference in post‐thaw semen quality traits between 20 million conventional packaging and 5 million spermatozoa/dose in modified packaging. In conclusions, the modified packaging is a very effective method for low‐dose cryopreservation with acceptable post‐thaw semen quality.

Laser irradiation effects and its possible mechanisms of action on spermatozoa functions in domestic animals

This article presents a review pertains the laser irradiation effects and its possible mechanisms of action on spermatozoa functions in domestic animals. To improve artificial insemination, laser is sensitive and cost effective technique, when compared to other conventional methods. Laser may have both positive and negative effects on spermatozoa functions. Since the effects of light are mediated by reactive oxygen species, and the levels of these reactive oxygen species following irradiating spermatozoa with laser may be responsible for determining the effects of laser on sperm. Dose of laser may be regarded as of great significance and this dosage of laser may be responsible for determining its effects on spermatozoa. Optimum dosage of laser for improving seminal attributes may vary among various species and this need to be standardized in each of them. The beneficial effects include improving sperm livability, acrosomal integrity, hypo-osmotic swelling response, mitochondrial function and computer-aided sperm analysis parameters. The increase in cytochrome c oxidase activity, ATP levels and mitochondrial membrane potential, in laser irradiated cells may be responsible for enhanced sperm quality parameters. Improving fertility with laser irradiated spermatozoa has been reported in few species like boar and need to be elaborated in other species. In conclusion laser may be regarded as an easy, cheap and time saving technology for improving artificial insemination; in addition, laser may have various potential applications in the field of reproductive biotechnology as well as in livestock farms and veterinary polyclinics.