Comparative Analysis Of Four Kinds Of Shan Dong Indigenous Chicken On Meat Performance And Meat Quality

The study is to investigate the characteristics of meat quality and meat performance about chickens from four local breeds named Wenshang Barred, Laiwu Black, Jining Bairi and Luxi Game. To test the meat quality and meat performance, 20(10♂+10♀) of 170-day-old and 280-day-old chickens were randomly selected from each breed that were raised under the same management and feeding condition. The testing items were composed of slaughter performance, routine physics and chemistry index, routine nutrients and animo acids. The results showed that :1. At the age of 170 and 280 days, Luxi Game was higher in body length,breast width,breast depth,fossil bone length and shank length than Laiwu Black, Wenshang Barred and Jining Bairi. So the body of Luxi Game is tall, and this adapts to the character of being good at fighting. The body type of the other three breeds is smaller.2. At the age of 170 and 280 days, Luxi Game was higher in body weight, half-eviscerated weight, eviscerated weight, breast muscle weight and leg muscle weight than the other three breeds. This is consistent with the charateristics of the largest body sizes.3. Dressing percentage and eviscerated percentage is generally recognized as the key indicators of chicken meat performance. It was considered as an indicator of good meat performance that the dressing percentage is over 80% and the eviscerated percentage was over 60%. The dressing percentage and eviscerated percentage of the four breeds are all respectively higher than 80% and 60%. It showed that the meat performance of the four breeds is good.4. At the age of 170 days, between body length, keel bone length and body weight before slaughter, slaughter weight, semi-eviscerated weight, eviscerated weight, leg weight, leg muscle weight and breast muscle weight showed a strong positive correlation(most of the correlation coefficient > 0.6). But at the age of 280 days, between body length and body weight before slaughter, slaughter weight, half-eviscerated weight, eviscerated weight showed a significant positive correlation(P<0.05). Between keel bone length and the dressing percentage showed medium to low degree of very significant negative correlation(P<0.05), but the correlation of it with other slaugher index was not significant(P>0.05).5. At the age of 170 days, the rate of water loss and drip loss of the chest muscle of Luxi Game cocks and hens and the leg muscle of Luxi Game cocks were the highest of the four breeds.The rate of water loss respectively were 33.05%,34.30% and 28.34%,and the drip loss respectively were 4.09%,4.13% and 3.75%. The rate of water loss and drip loss of the leg muscle of Jining Bairi was the highest of the four breeds,they were 34.53% and 2.53%,and it was significantly higher than the other three breeds. At the age of 280 days, The rate of water loss and drip loss of the four breeds were same.It showed that the water retention performance of Laiwu Black and Wenshang Barred were better than Jining Bairi and Luxi Game.6. The moisture content of the chicken is usually in the range of 70%- 75%.In this study,the moisture contents of the four breeds were within the normal range. At the age of 170 days,the intramuscular fat content of Jining Bairi and Luxi Game were relatively higher,while Wenshang Barred and Jining Bairi were relatively higher at the age of 280 days, Laiwu Black and Luxi Game were relatively lower. The results showed that the ability of fat deposition of Jining Bairi was the strongest, and which of the Laiwu Black was the weakest.7. According to the pattern of the FAO/WHO standard, the proportion of essential amino acids was about 40% at the amino acid composition of high-quality protein.In this study we explored that the proportion of essential amino acids of the breast muscle of the four 170-days-old breeds were above 40%. The proportion of essential amino acids of 280-days-old Laiwu Black and Wenshang Barred were under 40%,but were very close to 40%. It showed that the four breeds were a good source of protein. At the age of 170 days, Luxi Game was the highest of the four breeds in the content of total amino acid associated with sweetness and freshness. But at the age of 280 days, Laiwu Black became the highest,and the rate of Wenshang Barred and Jining Bairi were lower than the other breeds.It showed that the chichen flavor of 170-days-old Luxi Game and 280-days-old Laiwu Black were better than the other breeds.