Last update: August 15, 2011 08:56:58 AM E-mail Print


Energy expenditure in confined and free-ranging goats and sheep

M J Herselman*, S P Hart & T Sahlu

E (Kika) de la Garza Institute for Goat Research,

Langston University, Langston, OK, USA


The objective of this study was to investigate increased energy requirements in grazing versus confined animals by measuring energy expenditure. The carbon dioxide entry rate technique was used to measure energy expenditure in 24 confined animals, 30 goats and sheep grazing three paddocks (0.7 ha each) of mature Old World Bluestem grass (Bothriochloa caucasica) and 30 similar animals grazing three paddocks (10.8 ha each) of native range. Feed intake in the confined and fecal output in the grazing animals were recorded daily. Behavioural observations were done during one of the three 24 hour periods of saliva collection in the free-ranging animals. Energy expenditure in confined Alpine, Angora and Spanish goats and in sheep was 0.654, 0.510, 0.408 and 0.584 MJ/kg0.75/d respectively and was linearly related (P<0.01) to feed intakes of 55.2, 41.7, 25.1 and 49.8 g/kg0.75/d for the respective breeds. Energy expenditure was 0.566, 0.746 and 0.678 MJ/kg0.75/d on Old World Bluestem pasture for Angora goats, sheep and Spanish goats and 0.651, 0.799 and 0.700 MJ/kg0.75/d respectively on native range. Energy expenditure was linearly related (P<0.01) to fecal outputs of 12.5, 19.6 and 19.3 g/kg0.75/d on Old World Bluestem pasture and 19.6, 23.4 and 20.3 g/kg0.75/d on native range for the respective breeds. Energy expenditure at pasture was correlated with steps walked (r=0.38; P<0.01), grazing time (r=0.49; P<0.01), resting time (r= -0.60; P<0.01) and herding the animals for saliva collection (r=0.47; P<0.01). No evidence was found to support the view that behavioural differences between sheep and goats may cause larger increases in heat production of goats when confined and grazing animals are compared.



Proceedings 33rd SASAS congress