| 1 | Jugular arginine supplementation increases lactation performance and nitrogen utilization efficiency in lactating dairy cows显示文摘Background: Enhancing the post-ruminal supply of arginine(Arg), a semi-essential amino acid(AA), elicits positive effects on milk production. Our objective was to determine the effects of Arg infusion on milk production parameters and aspects of nitrogen(N) absorption and utilization in lactating dairy cows. Six lactating Chinese Holstein cows of similar body weight(508 ± 14 kg), body condition score(3.0 ± 0), parity(4.0 ± 0), milk yield(30.6 ±1.8 kg) and days in milk(20 ± 2 d) were randomly assigned to 3 treatments in a replicated 3 × 3 Latin square design with 21 d for each period(1 week for infusion and 2 weeks for washout). Treatments were 1) Control: saline;2) Arg group: saline + 9.42 g/L L-Arg;3) Alanine(Ala) group: saline + 19.31 g/L L-Ala(iso-nitrogenous to the Arg group). Milk production and composition, dry matter intake, apparent absorption of N, profiles of amino acids(AA) in blood,urea N in urine, milk, and blood, and gene expression of AA transporters were determined.Results: Compared with the Control or Ala group, the infusion of Arg led to greater expression of AA transporters(SLC7 A2 and SLC7 A8) and apparent uptake of free AA in the mammary gland, and was accompanied by greater milk yield, milk protein yield and milk efficiency(calculated by dividing milk yield over feed intake), together with lower concentration of urea N [regarded as an indicator of N utilization efficiency(NUE)] in blood and milk. Furthermore, in the cows infused with Arg, the NUE was higher and the concentration of urea N in urine was lower than those in the Ala group, although no differences were detected in NUE and urea N in urine between the Control and Arg group.The infusion of Ala had no effect on those indices compared with the Control.Conclusions: Overall, enhancing the post-ruminal supply of Arg via the jugular vein had a positive effect on the synthesis of milk protein at least in part by increasing gene expression of some AA transporters and uptake of free AA by mammary gland. | Luoyang Ding Yizhao Shen Yifan Wang Gang Zhou Xin Zhang Mengzhi Wang Juan J.Loor Lianmin Chen Jun Zhang | 2019 | Journal of Animal Science and Biotechnology2019，10，2： | 3 |
| 2 | Effect of surface damage induced by cavitation erosion on pitting and passive behaviors of 304L stainless steel显示文摘The corrosion behavior of 304L stainless steel(SS)in 3.5wt%NaCl solution after different cavitation erosion(CE)times was mainly evaluated using electrochemical noise and potentiostatic polarization techniques.It was found that the antagonism effect resulting in the passivation and depassivation of 304L SS had significant distinctions at different CE periods.The passive behavior was predominant during the incubation period of CE where the metastable pitting initiated at the surface of 304L SS.Over the rising period of CE,the 304L SS experienced a transition from passivation to depassivation,leading to the massive growth of metastable pitting and stable pitting.The depassivation of304L SS was found to be dominant at the stable period of CE where serious localized corrosion occurred. | Liang Li Yanxin Qiao Lianmin Zhang Aili Ma Enobong Felix Daniel Rongyao Ma Jian Chen Yugui Zheng | 2023 | International Journal of Minerals,Metallurgy and Materials2023，30，7： | 0 |
您所在的机构暂未开通此部分的功能，请联系管理员