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Context: The conflicting findings regarding the impact of equilibration time on post-thawed sperm quality underscore the need for further research to evaluate the impact of equilibration time and cooling rate on post-thaw sperm quality of ram semen. Aims: The current study aimed to assess the combined impact of cooling rates and pre-freezing equilibration times on post-thaw sperm quality in Kail ram semen (n = 5). Methods: Semen collection was performed using an artificial vagina at 42°C. The pooled semen was divided into equal aliquots and subjected to either slow cooling (SC, −0.27°C/min) or moderate cooling (MC, −0.36°C/min) rates, transitioning from 37°C to 4°C. Equilibration times of 0, 4, 8, and 12 h were employed before freezing. Key results: Semen samples undergoing the SC rate and equilibrated for 4 h exhibited higher (P < 0.05) percentages of progressive motile (PM), rapid progressive (RP), and medium progressive (MP) sperm compared with the MC rate. However, total motility remained unaffected by the cooling rate (P < 0.05). Semen equilibrated for 4 h demonstrated higher (P < 0.05) percentages of PM and RP sperm, as well as improved kinematics (curvilinear velocity, average path velocity, and straight-line velocity) compared with other equilibration times. Nevertheless, equilibration time had no (P > 0.05) impact on the amplitude of the lateral head displacement for semen samples subjected to the MC rate. Notably, the cooling rate did not affect post-thaw sperm kinematics, plasma membrane integrity, or live-sperm percentage (P > 0.05). Semen samples equilibrated for 4, 8, and 12 h exhibited a higher (P < 0.05) percentage of sperm with intact plasma membrane and viability than did those equilibrated for 0 h. Conclusions: In conclusion, slow cooling rate and a 4 h equilibration period were shown to be optimal for preserving post-thaw sperm quality in Kail rams. Implications: The findings highlighted the combined effect of cooling rate and equilibration time on post-thaw sperm quality for optimising sperm cryopreservation protocols in the context of ram semen. The conflicting results regarding the impact of equilibration time on sperm quality warrant further research to improve the post-thaw sperm quality of ram semen. The findings of the present study indicated that slow cooling and equilibration time of 4 h better-preserved sperm quality. The optimisation of sperm-freezing protocol will be beneficial for the widespread use of artificial insemination in sheep. [ABSTRACT FROM AUTHOR]

The Cholistani cow is considered one of the milch breeds of Zebu cattle. Despite being heat and tick-resistant, it has not yet gained much popularity among Pakistan dairy farmers due to its long calving interval. This study aimed to understand the basic reproductive physiology of Cholistani cows using sonography and reproductive biotechnologies such as estrus synchronization and timed artificial insemination to improve reproductive efficiency. In experiment 1, six Cholistani cows with mixed parity 3.20 ± 1.30 and weighing 400 kg were selected to monitor ovarian dynamics on alternate days by the same sonographer from the onset of heat through ovulation until the next ovulation. Experiment 2 measured the effect of estrus synchronization methods, controlled internal drug release-gonadotropin-releasing hormone (CIDR-GnRH, n = 31) and Ovsynch (OVS, n = 32) on various reproductive parameters. The mean estrous cycle length was 19.81 ± 0.56 days with two follicular waves. The mean interovulatory interval was 20.80 ± 0.52 days, with a preovulatory follicular size of 13.83 ± 2.37 mm. Estrus response was higher (p > 0.05) in controlled internal drug release (CIDR)-GnRH (93.54%) than in OVS (84.37%) cows. Similarly, ovulation and conception rates were higher in CIDR-GnRH (91.66% vs. 68.42%) than in OVS cows (41.37% vs. 33.33%), respectively. In conclusion, CIDR-GnRH results in a better estrus response, higher ovulation rate, and subsequently greater conception rate than OVS in Bos indicus dairy cows. [ABSTRACT FROM AUTHOR]

Introduction: Minerals play an essential role in the reproductive performance of dairy animals, especially in buffaloes. The present study aimed to evaluate the mineral concentrations in different types of samples, including soil used for fodder cultivation, canal water used for fodder irrigation, drinking water for buffaloes, fodder used for buffalo feeding, and serum of buffaloes and their effects on the reproductive efficiency of buffaloes. Materials and methods: The current study was carried out for three months and samples were analyzed twice at the beginning and the end of the study. The concentrations of calcium, magnesium, and inorganic phosphorus in the soil were checked through the versinate method. The concentration of calcium, magnesium, and inorganic phosphorus in water was checked through the titration method and the concentration of calcium, magnesium, and inorganic phosphorus contents in fodder was checked through the wet digestion method. The minerals of blood serum (n = 80) were analyzed through commercial kits. Results: In canal water, calcium concentration was higher for irrigation compared to buffalo drinking water. Similarly, on the upper surface of the soil compared to its lower surface, the level of calcium was high. Calcium values of serum were higher in cyclic buffaloes compared to buffalo heifers. In comparison to all groups, the levels of inorganic phosphorus were found to be lower in non-cyclic buffaloes. Similarly, the calcium-tophosphorus ratio was found to be lower in non-cyclic buffaloes and heifers compared to repeat breeders and cyclic buffaloes. At the beginning of the study, cyclic buffaloes had higher magnesium levels than all other groups, except for non-cyclic buffaloes. By the end of the study, magnesium concentrations were higher in non-cyclic buffaloes and heifers compared to repeat breeders and cyclic buffaloes. Conclusion: The mineral deficiencies in water and soil can affect the fodder content in the feed of buffaloes. [ABSTRACT FROM AUTHOR]