Serum LH concentrations in cyclic buffalo (Bubalus bubalis

Summary. Circulating LH levels of 14 Murrah buffaloes were determined by a double-antibody radioimmunoassay using an homologous bovine system. At the onset of oestrus, the mean peak circulating LH level was 20\m=.\80 \m=+-\3\m=.\43(s.e.m.) ng/ml in the hotter months (June\p=n-\August)and 21\p=n-\24\m=+-\0\m=.\98ng/ml during the cooler months (October\p=n-\December), values remaining high for about 4 h. Basal levels throughout the rest of the cycle averaged 1\p=n-\2ng/ml. Conception occurred in 7 of the animals showing LH peaks (2/8 in June\p=n-\August,5/6 in October\p=n-\December)