Requirements and energy efficiency of Pelibuey and Katahdin non pregnant, non lactating ewes in Yucatan, Mexico

Objective. To estimate metabolizable energy requirements for maintenance (MEm), energy efficiency of weight gain (EEWG) and fat thickness, in Pelibuey and Katahdin ewes in Yucatan, Mexico. Materials and methods. Eight non pregnant, non lactating, multiparous ewes, were feed at three intake levels with a diet containing 2.0 Mcal/Kg-1 of ME and 11 % of CP. Feed intake was measured daily, ewes weight and thickness of subcutaneous fat (SF) were determined every 14 days. The EMm was estimated by regressing values of live weight against metabolizable energy intake (MEI), EEWG was estimate as gram of weight gain per Mcal of MEI. Results. There were no differences between breeds in MEm (97±4 and 110±4 kcal/Kg0.75, for Pelibuey and Katahdin) and EEWG (58±8 and 63±8 g/Mcal of MEI, for Pelibuey and Katahdin); differences were found in SF (6.1±0.2 and 4.9±0.2 mm, for Pelibuey and Katahdin). Conclusions. The energy requirements for maintenance were similar in Pelibuey and Katahdin ewes in Yucatan, Mexico.