Published online by Cambridge University Press: 18 August 2016
A comparison was made of various devices to obtain preantral follicles from bovine ovaries. The most productive collection methods in terms of number of follicles obtained were the tissue chopper and the grinder method, with an average number of 122·25 (s.e. 5·06) and 120·45 (s.e. 6·89) preantral follicles, respectively. These were followed by ficoll gradation (119·90, s.e. 7·95), mincer (101·75, s.e. 3·98), cell dissociation sieve (100·50, s.e. 3·42) and homogenizer (95·75, s.e. 6·38). For enzymatic digestion, more time was needed and the method was less productive. Microdissection could supply good quality (80% live when collected), larger sized follicles (120 to 220 µm) but with the lowest yield (10·65, s.e. 0·94) per ovary. The isolated follicles did not show any difference (P > 0·05) in viability until day 7 of in-vitro culture irrespective of method used to harvest follicles. Accordingly the new grinding device can be recommended as a replacement for the existing mechanical devices as it can yield the same percentage (47%) of live preantral follicles but of a wider diameter range (40 to 180 µm) per ovary.