Study On The Crossbreeding Effects Of Beef Cattle Sired By Wagyu And The Corresponding Key Feeding Technologies

Japan Wagyu was introduced to crossbreed and improve the Chinese Simmental Taihang population cattle using the artificial insemination technology in this study, and high-grade beef was produced by stage-finishing method, which is of practical significance to promote the beef industry level in Shanxi province. The research is mainly divided into three parts and the main research results are as follows:In experiment one,60 healthy F1 hybrid bulls sired by Wagyu with the similar weight and body condition were chosen and divided into experimental and control groups. The animals were two years old and weighted about 430 kg. Pre-feeding period lasted for 15 days and the feeding period for 150 days. Stage-finishing method was used to investigate the body weight and body structure of the animals at the beginning and the end of experiment, respectively. After finishing, animals were slaughtered, and slaughter traits and meat quality traits were recorded. The results showed that the body weight of the hybrid cattle were 690±8 kg, and the average daily gain was 1.28±0.12 kg, which was increased by 19.6% compared to the Simmental (1.07±0.18 kg). Additionally, the slaughter rate of the F) hybrid, the ratio of the carcass and the meat bone ratio was 58.09%,83.53% and 5.07%, respectively. The quality beef cattle (72) accounted for 72% of the slaughtered experimental animals (100). In the F1 hybrid, loin eye area, cold carcass pH, shear force, drip loss, fat coverage and cooked meat rate was 118.32±3.80 cm2,5.45±0.51,4.58±0.32 kg,29.80±0.13%,87±5.24% and 45.25±0.58%, respectively.In experiment two, effects of different additives on beef cattle growth and slaughtering performance were investigated by adding different additives in the high concentrate feed. Results can provide reference for rational selection and the usage of additives during the beef production. The results showed that the finishing weight gain were significantly (P< 0.05) higher in group Ⅰ and Ⅱ than that in the control group, along with the average daily gain showed no significant difference. However, the difference was significant during the second month, which may means No.1 additive group can adjust fat deposition better than the No.2 additive. Compared to the control (51.23%), the slaughtering rate for the two treatment groups increased by 14.42%(58.62%) and 17.74%(60.32%), respectively, which showed significantly (P< 0.05) increases. The rate of carcass meat and meat bone showed significantly (P< 0.05) promotion in the experimental groups than that in the control group. Beef quality index of eye muscle area, shear force, marbling were better in the two groups than in the control significantly (P< 0.05). That means the additives can increase the meat production performance during finishing stage of cattle through nutrition regulation, beef quality improvement and economic efficiency.In experiment three, the influence of different forages on the intramuscular fat deposition was investigated through long-term finishing. Forages used in this study were corn and wheat straws, and the animal was Fl hybrids sired by Wagyu. The results showed that no effects of different forages on the beef quality, and the dressing percentage, net meat percentage, meat to bone ratio, eye muscle area, marbling score and drip loss tend to be increased and the subcutaneous fat coverage, bone weight tend to be decreased for steers than bulls. That means that castration tends to improve the beef quality of the hybrid cattle. The cholesterol content in bulls fed wheat straw were higher than that in steer group and in bulls fed corn straw. Castration and roughage had no effect on the amino acids and long-chain fatty acid composition, but the polyunsaturated fatty acids in the beef of the steers tend to be more stable.