Co-Authors:
Bar-Peled, U., Hebrew University of Jerusalem, Faculty of Agriculture, PO Box 12, Rehovot, 76100, Israel, Agricultural Research Organization, Volcani Center, PO Box 6, Bet Dagan, 50250, Israel
Aharoni, Y., Agricultural Research Organization, Newe Ya'ar, North Research Center, PO Box 1021, Ramat Yishay, 30095, Israel
Robinzon, B., Hebrew University of Jerusalem, Faculty of Agriculture, PO Box 12, Rehovot, 76100, Israel
Bruckental, I., Agricultural Research Organization, Volcani Center, PO Box 6, Bet Dagan, 50250, Israel
Lehrer, R., Agricultural Research Organization, Volcani Center, PO Box 6, Bet Dagan, 50250, Israel
Maltz, E., Agricultural Research Organization, Volcani Center, PO Box 6, Bet Dagan, 50250, Israel
Knight, C., Hannah Research Institute, Ayr, KA6 5HL, United Kingdom
Kali, J., Agricultural Research Organization, Volcani Center, PO Box 6, Bet Dagan, 50250, Israel
Folman, Y., Agricultural Research Organization, Volcani Center, PO Box 6, Bet Dagan, 50250, Israel
Voet, H., Hebrew University of Jerusalem, Faculty of Agriculture, PO Box 12, Rehovot, 76100, Israel
Gacitua, H., Agricultural Research Organization, Volcani Center, PO Box 6, Bet Dagan, 50250, Israel
Tagari, H., Hebrew University of Jerusalem, Faculty of Agriculture, PO Box 12, Rehovot, 76100, Israel
Abstract:
Groups of 9 or 10 cows were assigned to one of three treatments 1) machine-milking three times daily, 2) machine-milking six times daily, and 3) suckling three times daily in addition to machine-milking three times daily. Treatments were conducted during the first 6 wk postpartum. During wk 5, digestibility of the diet was estimated by the indigestible neutral detergent fiber method. During wk 6, milk yield and dry matter intake (DMI) were recorded daily, and plasma concentrations of glucose, nonesterified fatty acids, urea, protein, growth hormone, insulin, insulin-like growth factor I, oxytocin, and prolactin were determined. Milk yields were 38.5, 46.8, and 52.7 kg/d, and DMI were 18.1, 21.2, and 17.2, for cows on treatments 1, 2, and 3, respectively. Plasma glucose concentrations decreased, and plasma nonesterified fatty acid concentrations increased, for cows on treatments 2 and 3 compared with cows on treatment 1. Digestibility of dry matter was 57.5, 60.5, and 60.6%; of organic matter was 62.6, 64.6, and 66.8%; and of crude protein was 59.3, 62.7, and 64.6% for cows on treatments 1, 2, and 3, respectively. Concentrations of all assayed hormones, except insulin, increased moderately for cows on treatment 2 compared with cows on treatment 1 and increased dramatically for cows on treatment 3. Insulin concentrations followed the opposite trend. The DMI were positively related to milk yields and negatively related to oxytocin concentrations. Digestibility was negatively related to plasma glucose concentrations in a nonlinear pattern. The possible involvement of hormones in improvement of digestibility is discussed.