Energy expenditure and activity of different types of small ruminants grazing varying pastures in the summer
Beker, A., T. A. Gipson, R. Puchala, A. R. Askar, K. Tesfai, G. D. Detweiler, A. Asmare, and A. L. GoetschJournal of Applied Animal Research 37:1-14. 2010
Objectives were to determine the activity energy cost for different types of goats as well as a breed of sheep and to evaluate methods of prediction. Thirty-two animals were used, with eight of four different types. Animal types were yearling Angora doeling goats, yearling Boer wether goats, yearling Spanish wether goats, and Rambouillet wether sheep slightly more than 2 yr of age. Two animals of each type were randomly allocated to one of four pastures 9.3, 12.3, 4.6, and 1.2 ha in area. Forage conditions varied markedly among pastures. The experiment was conducted in the summer with three periods, 30, 26, and 26 days in length. Energy expenditure (EE) was estimated from heart rate (HR) on pasture and EE:HR for each animal determined in a calorimetry system. A leg position/movement monitoring system and a GPS collar with position and movement sensors were used to estimate distance traveled and time spent grazing/eating, resting while lying, resting while standing, and walking without grazing/eating. EE attributable to activity (EEa%), expressed as a percentage of the ME requirement for maintenance plus activity in confinement, was determined based on total EE, BW, and ADG. Forage mass in the different pastures and periods ranged from 2801 to 8672 kg/h. ADG was similar among animal types (-4, 30, -1, and 8 g for Angora goats, Boer goats, Spanish goats, and sheep, respectively; SE = 8.2). Distance traveled was affected by an interaction (P < 0.05) between animal type and period (Angora goats: 2.98, 2.33, and 2.47; Boer goats: 3.17, 3.46, and 2.68; Spanish goats: 2.85, 5.28, and 3.30; sheep: 3.04, 3.43, and 2.25 km in periods 1, 2, and 3, respectively (SE = 0.423)). Time spent grazing was lowest among animal types (P < 0.05) for Angora goats (4.3, 8.4, 7.8, and 6.8 h/day) and time spent walking without grazing was lower (P < 0.05) for Angora goats and sheep than for Boer goats (1.7, 2.4, 2.1, and 1.2 h/day for Angora goats, Boer goats, Spanish goats, and sheep, respectively). Total EE was affected by an interaction (P < 0.05) between animal type and period (Angora goats: 5.89, 5.55, and 5.16; Boer goats: 9.63, 10.92, and 8.55; Spanish goats: 6.73, 8.17, and 7.02; sheep: 12.54, 11.84, and 12.93 MJ/day in periods 1, 2, and 3, respectively (SE = 0.442)). EEa% was affected by an interaction (P < 0.05) between animal type and period (Angora goats: 15.7, 17.4, and 15.1; Boer goats: 59.7, 67.4, and 34.4; Spanish goats: 46.2, 61.7, and 41.6; sheep: 22.3, 11.8, and 21.9% in periods 1, 2, and 3, respectively (SE = 6.07)). EEa% of goats was predicted with moderate accuracy (R2 = 0.40-0.41) and without bias from estimates of 5.79 and 5.05%/h spent grazing/eating and grazing/eating plus walking, respectively, determined in a companion experiment; however, these methods were not suitable for sheep.
Extension Activities | Research Activities | Other Activities
Library Activities | Quiz | Search | About Us | Contact Us | Faculty & Staff
Research Extension Home | Top of Page
Copyright© 2000 Langston University Agricultural Research and Extension Programs
P.O. Box 730 Langston, OK 73050 Phone 405.466.3836