Avoid Inbreeding In Flock

Otago Daily Times, Issue 26713, 6 March 1948, Page 4

Avoid Inbreeding In Flock

The risks attendant on the amount of inbreeding which is likely to occur in the average flock are in most cases greatly exaggerated, states a bulletin issued to the Daily Times by Massey College. The belief that inbreeding must be avoided at all costs is widespread and most rams are not used after their third season and are sold as five-year rams.

Rams which have been carefully managed may remain fertile and vigorous for many years, and it is not uncommon for stud rams to be useful after 10 or more years of service. Flock rams are seldom used after six years of age, and in the majority of flocks they are sold before it becomes possible for them to be mated with their own daughters; which could occur m their third and subsequent seasons where the two-tooths are not tupped separately; while in their fifth and subsequent seasons they could be mated with their own granddaughters.

To avoid inbreeding in the flock many systems can be devised. If rams from one year and a-half to four years and a-half old are in use, the only rams which might be mated to their own daughters are the three and a-half and four year and a-half rams. Put the four year and a-half rams to the twotooth ewes (there will, however, be some of these ewes which are daughters of four year and a-half rams). If the ewe lambs of the two year and a-half rams are always distinctly marked at docking so that they can be distinguished when two-tooths, they can be mated to any other than four year and a-half rams, amongst which will be their sires. If rams from one year and a-half to five years and a-half are in use and the five year and a-half rams are mated only to the fresh fullmouthed (four year and a-half) and older ewes, the system described above will still apply.