POPULATION-STRUCTURE OF THE SAHIWAL BREED IN PAKISTAN

The present study tons undertaken to assist conservation and improveme nt schemes in the Sahiwal breed of cattle in Pakistan. A data set, con sisting of records of 244 pure Sahiwal breeding bulls and 5247 cows, t he latter representing about 80% of all recorded Sahiwal cows in Pakis tan born during a period covering about 20 years, was analysed with re gard to inbreeding, additive relationships, effective population size and generation intervals. Average inbreeding coefficients of 1224 cows and 49 bulls, for which at least the grandparents and great-grandsire s were known, were 0.043 and 0.046, respectively. About two-thirds of the inbreeding was due to matings between animals with parents or gran dparents in common. The mean additive relationship among the cows was 0.062, with within-herd averages ranging from 0.087 to 0.358. The aver age population size in a subdata set of recorded Sahiwal cattle from 1 980 to 1984 was 1612, whereas the most likely estimate of the effectiv e population size was about 30 animals for the same active breeding po pulation. The study indicated the immediate need for an active conserv ation programme whereby the Sahiwal subpopulations of India and Kenya also should be involved.