Resumo

CHAY-CANUL, Alfonso Juventino et al. Energy requirements of hair sheep in the tropical regions of Latin America. Review. Rev. mex. de cienc. pecuarias [online]. 2016, vol.7, n.1, pp.105-125. ISSN 2448-6698.

Breeds of hair sheep play an important role in animal production in tropical regions; however, their nutrient requirements have not been determined to the same extent as those of wool breeds. Due to the environmental conditions of the tropical regions (climate, quality and availability of feedstuffs), it is reasonable to hypothesize that energy requirements and efficiency of utilization of metabolizable energy (ME) may be different between hair and wool breeds of sheep. Information available on hair sheep shows a large discrepancy regarding energy requirements. Based on available literature data for female sheep, ME requirement for maintenance (MEm) was 419±129 kJ/ kg BW0.75 (mean ± standard deviation) and for the male 388±123 kJ/kg BW0.75. The requirement of net energy for gain (NE g ) ranged from 8.75 to 14.06 kJ/g (11.63±1.86 kJ/g). The efficiency of ME utilization for maintenance (km ) and gain (kg ) were 0.66±0.02 and 0.42±0.04, respectively. This review indicated also that information is scarce for adult ewes at different physiological stages (maintenance, lactation, or pregnancy). More work is required regarding estimates of nutrient requirements of hair sheep in order to develop adjustments to existing nutrition models to predict animal’s response under the conditions prevailing in the tropics (animal type, environment and feedstuffs available).

Palavras-chave : Hair sheep; Energy requirements; Tropics; Maintenance; Gain; Efficiency.

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