The Effects Of Complex Trace Elements Sustained Release Preparation On Productivity And Security Evaluation In Dairy Cows

Many trace elements are essential to nutrition, production and life of animals. It is confirmed that deficiencies or excesses caused losses through decreased production and growth. Purpose of this study was to investigate the effects of complex trace elements sustained release preparation, which was developed by Lanzhou institute of animal sciences and veterinary pharmaceutics of CAAS, on production of dairy cows. According to age, weight, and milk yield, twenty dairy cows were randomly divided into 2 groups (control and treatment)of 10 cows each, animals in treated Group were administered complex trace elements sustained release preparation by a pellet gun. In order to access the change of productivity, all animals weight and milk yield, fat, lactose, protein were observed on 0, 30, 60, and 90 days. At same time, activity of blood glutathione peroxidase (GSH-Px), malondialdehyde (MDA) serum levels, trace elements (including copper, zinc, selenium and iron) content in milk and serum were measured. The results as following: (1) Cows weight was increased significantly in treated animals than control animals (P<0.01). Increased values were 0.225 kg in treated group and 0.129 kg in control; (2) Daily milk yield was increased 0.47 Kg, fat, protein, lactose of milk were respectively increased 0.47%, 0.7%, 0.39% in treated group. These data all were better than control (P<0.05); (3) Activity of blood GSH-Px was increased markedly in treated animals (P<0.05) and MDA serum level was obviously lower in this group than control (P<0.01).In this study, the security of this preparation was estimated by acute toxicity and chronic toxicity . In acute test, 70 kunming mice (8-weeks-old) were randomly divided into 7 groups including Control, Ⅰ,Ⅱ,Ⅲ,Ⅳ,Ⅴ,Ⅵ,Ⅰ～Ⅵ groups mice were administered orally 1920 mg/kg, 2400 mg/kg,3000 mg/kg,3750 mg/kg,4688 mg/kg, 5859 mg/kg powder of complex trace elements sustained release preparation, respectively. The result showed that LD50 was 4342 mg/kg, and 95% confidence...