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חיפוש מתקדם
Livestock Production Science
Barkai, D., Department of Natural Resources, Gilat Research Center, Mobile Post Negev 2 85280, Israel
Landau, S., Department of Natural Resources, Institute of Field and Garden Crops, Agricultural Research Organization, P.O. Box 6, Bet Dagan 50250, Israel
Brosh, A., Beef Cattle Department, Agricultural Research Organization, Newe Yaar Research Center, P.O. Box 1021, Ramat Yishai 30095, Israel
Baram, H., Department of Natural Resources, Institute of Field and Garden Crops, Agricultural Research Organization, P.O. Box 6, Bet Dagan 50250, Israel
Molle, G., Istituto Zootecnico E Caseario Per La Sardegna, Olmedo (SS) 07040, Italy
We studied the feasibility of using heart rate (HR), or energy expenditure (EE), calculated as HR multiplied by O2 pulse - The amount of O2 delivered to the body at every heartbeat - To estimate individual intake of metabolisable energy (MEI) in lambs. HR was automatically recorded every 20 min during 48 h, and averaged daily (HRmean), in eight confined lambs fed with 1 kg of concentrate (C), 600 g of concentrate and 400 g of vetch hay (CH), or concentrate ad libitum (CC) or grazing lush green alfalfa (A). O2 pulse was measured for 10 min a.m. and p.m., using an open-circuit respiratory system, simultaneously with HR measurements. Dietary treatments and time of measurement did not affect O2 pulse significantly. Diurnal lowest HR (HRmin) was found at night for all treatments, and highest HR (HRmax) was recorded between 1000 to 1200 in all treatments but CC. Diurnal HRmean was lowest in CH and highest in CC (P < 0.04), the other treatments being intermediate. HRmin was the highest in CC (P < 0.02). Rumination was associated with lower HR than grazing, idling being intermediate (P < 0.001). Diurnal HRmean, but not EE, was significantly related with ME intake in confinement (R2 = 0.17, P < 0.05), or at pasture (R2= 0.55, P < 0.01), and not accurately enough for predictive purposes (R.S.D. 100 to 130 MJ kg-1 BW0.75). This low accuracy was probably more related with large individual variation, and with environmental effects on HR, than with lack of linearity between MEI and HR, because group means of MEI were well related with HRmean or EE (R2 = 0.99 and R2 = 0.97, respectively). © 2002 Elsevier Science B.V. All rights reserved.
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הספר "אוצר וולקני"
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תנאי שימוש
Estimation of energy intake from heart rate and energy expenditure in sheep under confinement or grazing condition
73
Barkai, D., Department of Natural Resources, Gilat Research Center, Mobile Post Negev 2 85280, Israel
Landau, S., Department of Natural Resources, Institute of Field and Garden Crops, Agricultural Research Organization, P.O. Box 6, Bet Dagan 50250, Israel
Brosh, A., Beef Cattle Department, Agricultural Research Organization, Newe Yaar Research Center, P.O. Box 1021, Ramat Yishai 30095, Israel
Baram, H., Department of Natural Resources, Institute of Field and Garden Crops, Agricultural Research Organization, P.O. Box 6, Bet Dagan 50250, Israel
Molle, G., Istituto Zootecnico E Caseario Per La Sardegna, Olmedo (SS) 07040, Italy
Estimation of energy intake from heart rate and energy expenditure in sheep under confinement or grazing condition
We studied the feasibility of using heart rate (HR), or energy expenditure (EE), calculated as HR multiplied by O2 pulse - The amount of O2 delivered to the body at every heartbeat - To estimate individual intake of metabolisable energy (MEI) in lambs. HR was automatically recorded every 20 min during 48 h, and averaged daily (HRmean), in eight confined lambs fed with 1 kg of concentrate (C), 600 g of concentrate and 400 g of vetch hay (CH), or concentrate ad libitum (CC) or grazing lush green alfalfa (A). O2 pulse was measured for 10 min a.m. and p.m., using an open-circuit respiratory system, simultaneously with HR measurements. Dietary treatments and time of measurement did not affect O2 pulse significantly. Diurnal lowest HR (HRmin) was found at night for all treatments, and highest HR (HRmax) was recorded between 1000 to 1200 in all treatments but CC. Diurnal HRmean was lowest in CH and highest in CC (P < 0.04), the other treatments being intermediate. HRmin was the highest in CC (P < 0.02). Rumination was associated with lower HR than grazing, idling being intermediate (P < 0.001). Diurnal HRmean, but not EE, was significantly related with ME intake in confinement (R2 = 0.17, P < 0.05), or at pasture (R2= 0.55, P < 0.01), and not accurately enough for predictive purposes (R.S.D. 100 to 130 MJ kg-1 BW0.75). This low accuracy was probably more related with large individual variation, and with environmental effects on HR, than with lack of linearity between MEI and HR, because group means of MEI were well related with HRmean or EE (R2 = 0.99 and R2 = 0.97, respectively). © 2002 Elsevier Science B.V. All rights reserved.
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