חיפוש מתקדם
Journal of Animal Science
Brosh, A., Agricultural Research Organization, Institute of Animal Science, Newe Ya'ar Research Center, P.O. Box 1021, Ramat Yishay, 30095, Israel
Aharoni, Y., Agricultural Research Organization, Institute of Animal Science, Newe Ya'ar Research Center, P.O. Box 1021, Ramat Yishay, 30095, Israel
Degen, A.A., Desert Anim. Adaptations and Husb., Jacob Blaustein Inst. Desert Res., Ben-Gurion University of the Negev, Beer Sheva 84105, Israel
Wright, D., Dept. Companion Anim. Med. and Surg., University of Queensland, St. Lucia, QLD 4067, Australia
Young, B.A.
Ten growing heifers were either exposed to or protected from solar radiation, offered a diet of either high (H) or low (L) ME, and fed either in the morning or afternoon during a hot summer. Heifers that consumed the H diet had a greater water intake, DMI, metabolizable energy intake, energy expenditure, and retained energy than heifers that consumed the L diet. Solar radiation did not have an effect on any of these variables. Furthermore, dietary energy and time of measurement had an effect on rectal temperature (Tr), respiration rate (RR), heart rate (HR), and rate of oxygen uptake (VO2); solar radiation had an effect on Tr and RR but not on HR and VO2; and time of feeding had an effect only on VO2. Heifers coped with greater heat loads by increasing RR and the difference in Tr between morning and afternoon. It seems that a lowered body temperature in the morning is a physiological mechanism used by animals to prepare for the heat load that develops during the day. Heat production (HP) and HR throughout the day were affected mainly by the time of feeding and not by the environmental heat load. Feeding in the afternoon increased HP in the cooler hours of the day when heat losses from the animal through conduction and radiation were more efficient. With a pending high heat load situation, reducing feed quality and(or) changing the time of feeding to the late afternoon could be beneficial to the animals in reducing their heat loads.
פותח על ידי קלירמאש פתרונות בע"מ -
הספר "אוצר וולקני"
אודות
תנאי שימוש
Effects of Solar Radiation, Dietary Energy, and Time of Feeding on Thermoregulatory Responses and Energy Balance in Cattle in a Hot Environment
76
Brosh, A., Agricultural Research Organization, Institute of Animal Science, Newe Ya'ar Research Center, P.O. Box 1021, Ramat Yishay, 30095, Israel
Aharoni, Y., Agricultural Research Organization, Institute of Animal Science, Newe Ya'ar Research Center, P.O. Box 1021, Ramat Yishay, 30095, Israel
Degen, A.A., Desert Anim. Adaptations and Husb., Jacob Blaustein Inst. Desert Res., Ben-Gurion University of the Negev, Beer Sheva 84105, Israel
Wright, D., Dept. Companion Anim. Med. and Surg., University of Queensland, St. Lucia, QLD 4067, Australia
Young, B.A.
Effects of Solar Radiation, Dietary Energy, and Time of Feeding on Thermoregulatory Responses and Energy Balance in Cattle in a Hot Environment
Ten growing heifers were either exposed to or protected from solar radiation, offered a diet of either high (H) or low (L) ME, and fed either in the morning or afternoon during a hot summer. Heifers that consumed the H diet had a greater water intake, DMI, metabolizable energy intake, energy expenditure, and retained energy than heifers that consumed the L diet. Solar radiation did not have an effect on any of these variables. Furthermore, dietary energy and time of measurement had an effect on rectal temperature (Tr), respiration rate (RR), heart rate (HR), and rate of oxygen uptake (VO2); solar radiation had an effect on Tr and RR but not on HR and VO2; and time of feeding had an effect only on VO2. Heifers coped with greater heat loads by increasing RR and the difference in Tr between morning and afternoon. It seems that a lowered body temperature in the morning is a physiological mechanism used by animals to prepare for the heat load that develops during the day. Heat production (HP) and HR throughout the day were affected mainly by the time of feeding and not by the environmental heat load. Feeding in the afternoon increased HP in the cooler hours of the day when heat losses from the animal through conduction and radiation were more efficient. With a pending high heat load situation, reducing feed quality and(or) changing the time of feeding to the late afternoon could be beneficial to the animals in reducing their heat loads.
Scientific Publication
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