Seasonal variations in semen quality, freezability and plasma luteinizing hormone (LH) levels were studied between summer and spring. Semen volume, density and initial sperm motility did not differ significantly between different seasons. Plasma LH decreased between summer and spring but the differences were, however, not significant. Pre-freezing motility did not differ significantly but post-freezing motility varied significantly (P less than 0.01) between seasons. Post-freezing motility was lowest during summer and highest during winter. It can be concluded that summer spermatozoa may be fragile and cannot withstand freezing stress. To increase reproductive efficiency in buffalo during summer, semen should be frozen during winter and spring and used during hot weather conditions. Seasonal variations in plasma LH levels were insignificant.

No abstract

The lowest value for plasma protein bound iodine (PBI) (3.47 micrograms %) in 20 freshly calved Murrah buffaloes was observed on day 1 postpartum. The values then increased consistently up to day 36 and were almost constant thereafter. The plasma progesterone concentrations were lower in animals with relatively low PBI from day 22 to 57 postpartum, except on day 36. The mean values +/- SE (ng/ml) in the high and low PBI groups were 0.93 +/- 0.09 and 0.72 +/- 0.15. The correlation coefficient between PBI and progesterone was 0.80 (p less than 0.01). Relatively poor reproductive efficiency, in terms of a higher initiation of follicular development interval, postpartum oestrus interval, service period and number of services for conception, was observed in animals in the low PBI group.

SUMMARYForty-five normal lactating buffaloes from Punjab Agricultural University, Dairy Farm herd, were used for this study and were divided into three groups as group I (control), group II (showers) and group III (wallowing). The study was conducted from May to September in two periods, May–June as period I (hot and dry) and July–September as period II (hot and humid). Potassium concentration was estimated on a flame photometer. The overall average values (m-equiv/l) were found to be lowest in the control group (21·5 ± 1·27) and highest in wallowing (24·3 ± 1·20). Lower values were obtained in period I than in period II. Different correlations of potassium concentration in red blood corpuscles with climatic variables are discussed. Erythrocyte potassium concentration may act as an index of heat tolerance in buffaloes.

No abstract