Dr. Kai LIU

Assistant Professor
BSc, PhD
Office Address
Room 1B-405, 4/F, Block 1B, To Yuen Building, 31 To Yuen Street, City University of Hong Kong
Office Tel
Office Fax

Dr. Kai Liu joined City University of Hong Kong in March 2019 as an Assistant Professor in Animal Welfare, Ethics and Behaviour. He contributes to the Bachelor of Veterinary Medicine by teaching courses in the areas of animal behaviour and welfare and intensive livestock production systems. He also conducts research in the area of precision livestock farming, mostly in poultry and swine production systems.

Kai obtained his PhD degree in Agricultural and Biosystems Engineering (Animal Production Systems Engineering) from Iowa State University, USA, and then joined the Swine Teaching and Research Center at the University of Pennsylvania, School of Veterinary Medicine, USA, as a postdoctoral researcher. His research there mainly focused on engineering and machine learning techniques to monitor and assess behaviour, health, welfare, and reproductivity of sows kept in loose housing, both in large groups during gestation and with alternative farrowing systems.

Kai has been named as the 2019 Class “New Faces of ASABE – Professionals” by the American Society of Agricultural and Biological Engineers. As an agricultural and biological engineer working in animal agriculture, he is dedicated to applying engineering strategies and innovation, and to seeking data-driven solutions to address global challenges related to food animal production and sustainability, particularly the ever-growing issues related to animal welfare and behaviour.

Precision Livestock Farming:

  • engineering strategies/innovation for real-time monitoring, assessment, and management of farming animals regarding their behaviour, health, production, reproduction, and welfare


Animal Housing and Environment Management:

  • alternative housing system design for farm animals
  • behaviour and production responses of farm animals to housing enrichments
  • novel lighting technologies for poultry production


Animal Behaviour and Welfare:

  • alternative housing systems for improved behaviour and welfare of farm animals

Please click here (Google Scholar) for a full list of publications.

Liu, K., Xin, H., Shepherd, T., & Zhao, Y. (2018).
Perch-shape preference and perching behaviors of young laying hens.
Applied Animal Behavior Science, 203: 34-41. doi: 10.1016/j.applanim.2018.02.009

Liu, K., Xin, H., Sekhon, J., & Wang, T. (2018).
Effects of fluorescent and poultry-specific light-emitting diode lights on production performance and egg quality of W-36 laying hens.
Poultry Science, 97: 834-844. doi: 10.3382/ps/pex371

Liu, K., Xin, H., & Settar, P. (2018).
Effects of light-emitting diode light versus fluorescent light on growing performance, activity levels and well-being of non-beak-trimmed W-36 pullets.
Animal, 12(1): 106-115. doi: 10.1017/S1751731117001240

Chai, L., Xin, H., Zhao, Y., Wang, T., Soupir, M., & Liu, K. (2018).
Mitigating ammonia emissions from liquid-sprayed litter of cage-free hen house with a solid litter additive.
Transactions of the ASABE, 61(1): 287-294. doi: 10.13031/trans.12481

Liu, K., Xin, H., & Chai, L. (2017).
Choice between fluorescent and poultry-specific LED lights by pullets and laying hens.
Transactions of the ASABE, 60(6): 2185-2195. doi: 10.13031/trans.12402

Liu, K. & Xin, H. (2017).
Effects of horizontal distance between perches on perching behaviors of Lohmann hens.
Applied Animal Behavioral Science, 194: 54-61. doi: 10.1016/j.applanim.2017.05.001

Xin, H. & Liu, K. (2017).
Precision livestock farming in egg production.
Animal Frontier, 7(1): 24-31. doi: 10.2527/af.2017.0105

Li, L., Zhao, Y., Oliverira, J., Verhoijsen, W., Liu, K., & Xin, H. (2017).
A UHF RFID system for studying individual feeding and nesting behaviors of group-housed laying hens.
Transactions of the ASABE, 60(4): 1337-1347. doi: 10.13031/trans.12202

Chai, L., Zhao, Y., Xin, H., Wang, T., Atilgan, A., Soupir, M., & Liu, K. (2017).
Reduction of particulate matter and ammonia by spraying acidic electrolyzed water onto litter of aviary hen houses-a lab-scale study.
Transactions of the ASABE, 60(2): 497-506. doi: 10.13031/trans.12081

Yang, Y., Jiang, J., Wang, Y., Liu, K., Yu, Y., Pan, J., & Ying, Y. (2016).
Light-emitting diode spectral sensitivity relationship with growth, feed Intake, meat, and manure characteristics in broilers.
Transactions of the ASABE, 59(5): 1361-1370. doi: 10.13031/trans.59.11325

Lao, F., Brown-Brandl, T. M., Stinn, J. P., Liu, K., Teng, G., & Xin, H. (2016).
Automatic recognition of lactating sow behaviors through depth image processing.
Computers and Electronics in Agriculture, 1259: 56-62. doi: 10.1016/j.compag.2016.04.026

Zhao, Y., Zhao, D., Ma, H., Liu, K., Atilgan, A., & Xin, H. (2016).
Environmental assessment of three egg production systems - part III: airborne bacteria concentrations and emissions.
Poultry Science, 95(7): 1473-1481. doi: 10.3382/ps/pew053

Zhao, Y., Xin, H., Zhao, D., Zheng, W., Tian, W., Ma, H., Liu, K., Hu, H., Wang, T., & Soupir, M. (2014).
Free chlorine loss during spraying of membraneless acidic electrolyzed water and its antimicrobial effect on airborne bacteria from poultry house.
Annals of Agricultural and Environmental Medicine, 21(2): 249-255. doi: 10.5604/1232-1966.1108585