[Effects of exogenous metallothionein on thermoresistance and SOD gene expression of dairy cattle].
To approach the effects of exogenous metallothionein (Zn-MT) on the thermoresistance and SOD gene expression of dairy cattle, an experiment was conducted with 28 lactating cows, which were randomly allocated to groups A, B, C and D, and supplemented with 0, 6.0, 12.0 and 16.0 mg Zn-MT x capita(-1), respectively, by intravenous injection. The results showed that the pulse, breath rate, and serum MDA content of the cows in groups B, C and D were lower (P < 0.05 or P < 0.01), while their milk yield, serum- and milk MT contents, blood GSH-PX activity, erythrocyte SOD activity, and SOD gene expression level were higher (P < 0.05 or P < 0.01) than those in group A. All the test indices of the cows in groups C and D were superior (P < 0.05 or P > 0.05) than those in group B, but no significant difference (P > 0.05) was observed between groups C and D. Exogenous Zn-MT had the best effects on the thermoresistance and SOD gene expression of dairy cattle 30 days after injection. All of these suggested that exogenous Zn-MT should be a physiologically active substance effective to the thermoresistance and SOD mRNA expression of dairy cattle, and presented time- and dose-dependent effects.
Zhang
Bin
B
College of Animal Science and Technology, Hunan Agricultural University, Changsha 410128, China. zhbin2119@hotmail.com
Xue
Li-qun
LQ
Li
Li-li
LL
De
Xing-hou
XH
Chen
Yu-guang
YG
Wang
Jie
J
Peng
Hui-zhen
HZ
Xiao
Ding-fu
DF
D000222:Adaptation, Physiological; D000818:Animals; D002417:Cattle; D003612:Dairying; D005260:Female; D015870:Gene Expression; D006358:Hot Temperature; D008668:Metallothionein / Q000494:pharmacology*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011897:Random Allocation; D013312:Stress, Physiological; D013482:Superoxide Dismutase / Q000096:biosynthesis* / Q000235:genetics
D012333:RNA, Messenger; D008668:Metallothionein; D013482:Superoxide Dismutase