ADDITIVE AND MULTIPLICATIVE ADJUSTMENT FACTORS FOR SOME GROWTH TRAITSIN ARABI SHEEP

Data on body weight (BW),body length (BL), heart girth (BH) at birth, daily gain from birth to weaning (DG), body weight (WW), body length ( WL) and heart girth (WH) at weaning were used to develop additive and multiplicative constants to remove the influence of sex, month of birt h and age of dam effects in Arabi lambs. Homogeneity test was conducte d on phenotypic variances of sex, month of birth and damage groups. A nonsignificant result indicated the use of additive constant, while mu ltiplicative constants preferred when the variance differences turned to be significant. Additive adjustments were recommended to adjust BW, BH, and WH for sex effect; DG and WW for month of birth effect; and B W, WW and WH for age of dam effect. Multiplicative constants appeared to be more appropriate to adjust BL, DG, WW and WL for sex effect; BW, BL, BH, WL and WH for month of birth effect; and BL, BH and WL for ag e of dam effect.