Modeling the dynamic response of camels' heart rate to physical activities Techane Bosona ⁎, Girma Gebresenbet, Fufa S. Bulitta Department of Energy and Technology, Swedish University of Agricultural Sciences, Box 7032; 750 07 Uppsala, Sweden article info abstract Article history: Received 23 August 2010 Received in revised form 4 July 2011 Accepted 12 July 2011 This paper presents the result of the study made on the dynamic response of camels' heart rate (HR) under working conditions. The main objective was to develop a simulation model that can describe the dynamic nature of the camels' heart rate response to physical activity i.e. pulling a loaded cart and sledge. The dynamic simulation model was developed using Powersim simulation software. The model verification and validation processes indicated that the model could describe the basic pattern of camels' dynamic heart rate response to physical activity. The coefficient of determination, R 2 , was more than or equal to 0.74 for seven of the eight data sets used for model development. This basic profile of the dynamic response of camels' heart rate had four parts: resting condition (before activity); transient; steady state; and recovery conditions. The heart rate rose rapidly, maintained steady state and then decreased gradually after the release of load. The statistical test indicated that the difference in animals (p b 0.0001), loads (p b 0.0001), and loading types (p b 0.0006) had significant effect on the HR response of experimental camels. © 2011 Elsevier B.V. All rights reserved. Keywords: Camel Heart rate Simulation model Steady state Time response function 1. Introduction Animal power is considered to be the most appropriate energy sources in developing countries for plowing, harrow- ing, dredging ditches, dam-scooping, pulling artillery, lifting water from wells, ore crushing, grinding oilseed, fighting, riding, pack transport and pulling (example pulling loaded carts, wagons and sledges) (Bobobee, 2007; Starkey, 2004). Animal power is a natural, ecologically sustainable and renewable energy source. Work animals aid productive crop-livestock integration in the rural communities where animal power is widely available and generally affordable. In addition to this, draft animals cause no pollution and environmental damage compared to motorized alternatives (Starkey, 2004). Camels are among animal species that have been used for a long time particularly for transporting goods and people because of their excellent adaptation to the desert and harsh conditions, where they are efficient in traveling long distances (Yagil et al., 1994). Camels are also milk producing animals in the desert areas (Farah et al., 2007; Yagil et al., 1994). The Middle East, northern and eastern Africa, India and Pakistan are the most camel-populated areas in the world (Bhutto et al., 2010; Farah et al., 2007). Camels are the most important animals especially in dry regions, and used mostly as pack animals. Camel carts are common in India and Pakistan (Akrai and Khanna, 1994). In recent years, the interest in the value of camel power has increased because of their carrying and pulling capacity. For appropriate utilization of working animals, it is necessary to maintain the welfare of these animals. One of the main causes of mortality is poor camel management practice (Farah et al., 2007). According to Starkey (2004), training service could help farmers train their work animals which could have effect on welfare. The other main problem is that loads that animals pull or carry haven't been optimized (Gebresenbet et al., 2006) and therefore animals are either overloaded or underutilized. Therefore the working conditions should be optimized to increase efficiency without compromising the animals' welfare (Gebresenbet et al., 2006). Livestock Science 142 (2011) 138–146 ⁎ Corresponding author. E-mail address: techane.gari.bosona@et.slu.se (T. Bosona). 1871-1413/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.livsci.2011.07.004 Contents lists available at ScienceDirect Livestock Science journal homepage: www.elsevier.com/locate/livsci