The relationship between head weight with total body weight during embryonic development in indigenous sheep

The study was carried out on (130) indigenous sheep fetuses with an estimated age ranged between (43 -147) days old (6 – 53 cm. crown– rump length), the total body weight of these fetuses ranged between (4.26– 3437 grams), while the weight of their heads ranged between (1.33 – 399.87 grams) for both sexes. The results revealed the followings: 1. High significant variance in the ratio between head weight and the total body weight of the 8th and 10th weeks of fetal age in both sexes. 2. Significant variance in the ratio between head weight and the total body weight in males higher than that in females of 10th and 13th weeks of fetal age, this variance decrease in both 8th, 19th weeks of fetal age,but it seems higher in females than in males in the 18th, 20th weeks of fetal age. 3. High significant correlation (p 0.001) between the head weight and total body weight. The correlation coefficient were 0.938 in males and 0.984 in females. 4. The regression equation of the total body weight was (6.215 × head weight)– 52.22 for males. 5. The regression equation of the total body weight was (6.475 × head weight)-100.898 for females.