USE OF VASECTOMISED RAMS

Press, Volume LXXXVII, Issue 26319, 13 January 1951, Page 5

USE OF VASECTOMISED RAMS

An experiment carried out on the Condobolin Experimental Farm, New South Wales, indicates that the use of vasectomised rams in the flock before mating results in earlier lambing and a higher lamb percentage than when normal mating takes place without the use of teaser rams. The trial was made with 184 Corriedale ewes, comprising 120 two-tooths and 64 full-mouth ewes. The sheep were split up into two lots of 32 aged ewes and 60 two-tooths. Each group was tagged for identification. Group A was run with three vasectomised rams from October 19, 1949, to November 9, when the vasectomised rams were withdrawn and the two groups boxed. Four Corriedale rams were then joined for a normal mating rriod of eight weeks from November to January 9, 1950. The results of the mating are shown in the following table of progressive results (each group comprised 92

Group A produced six lots of twins and Group B seven lots of twins; The significant feature of the trial is that 61 lambs were born to the “teaser” ram group during the first three weeks of, lambing, compared with 25 in the B group, while the total of lambs to ewes in the “teaser” group was 78.2 per cent., compared with 64.1 per cent-in Group B. The trial will be repeated this season, when the groups will be reversed.

ewes):— Group A Group B. Vasect. Rams. Norm. Mating. Lambed to April 11 26 9 Lambed to April 18 34 14 uambed to April 25 61 25 Lambed to May 2 .. 68 56 Lambed to May 9 .. 70 57 Lambed to May 16 .. 70 58 Lambed to May 23 .. 71 58 Lambed to May 30 .. , 72 59