Abstract:

The influence of maternal different dietary protein levels on muscle fiber and expression of Myostatin gene of offspring of two broiler lines was investigated. The maternal different dietary protein levels were 80%, 100% and 120% NRC level for maternal broiler breeder. The offspring was feed normal protein level diet. The results showed that: ⑴The maternal high protein diets increased the body weight of 1 day broilers significantly(P<0.05), but the body weight of 56 day broilers had no difference among treatments(P>0.05). ⑵ With the maternal protein levels decreased, muscle fiber diameter of breast of offspring was decreased, low protein group was significant lower than the normal and high protein groups(P<0.05), but there was no significant difference between the two lines. ⑶ With maternal protein levels decreased, muscle fiber density of breast of offspring was increased, low protein group was higher than the normal and high protein groups significantly(P<0.05), but there was no significant difference between
the two lines. ⑷The high protein diets of maternal broiler has a trend to decrease the expression level of offspring Myostatin gene（P>0.05）, compared to the normal and low protein groups, the expression level of Myostatin gene of lean line broilers breast of high protein group in 21 day was decreased significantly（P<0.05）.The results demonstrated that the maternal high protein diet increased the body weight of 1 day broilers significantly, and there are a trend that expression level of Myostatin gene was decreased in high protein group, the maternal low protein diet declined the muscle fiber diameter and increased the muscle fiber density, but there are no significant difference between the two lines（P>0.05）.

Key words: broiler breeder, protein level, muscle fiber, Myostatin