Vie CONG. INTERN. REPROD. ANIM. INSEM. ARTIF., PARIS, 1968, VOL. Il

per insemination. These differences may arise from the
relatively small number of inseminations on which the results
are based. However, the numbers of sows served by the
inseminator service in Britain is so limited that it is not
possible to improve this situation.

References
(1) F. du Mesnil du Buisson and L. Dauzier, 1958.
CiRAcads Scin,L i o247 24729="9475

(2) G.H. Bennett and C. 0'Hagan, 1964. Proc. 5th int. Congr.
Anim. Reprod. (Trento), 4: 482 - 487

(3) D.R. Melrose and C. 0'Hagan, 1959. Annales de Zootechnie,
8, Series D, Supplement 69

(4) D.R. Melrose and C. O'Hagan, 1961. Proc. 4th int. Congr.
Anim. Reprod. (The Hague), 4: 855 - 859

999