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چکیده
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The objective of this study was to compare the efficacyof the step-up/step-down (SUSD) and step-down(STP) methods of milk feeding on the performance,growth parameters, blood metabolites, and health ofdairy calves. For this purpose, 45 Holstein male calves(3 d of age and 41 ± 3 kg of body weight) were randomlyassigned to one of the following milk feedinggroups: (1) conventional (CONV; 4 L/d milk from d 1to 52, and 2 L/d milk from d 53 to 56 of the study),(2) STP (6 L/d milk from d 1 to 29, and 4 L/d milkfrom d 30 to 45 of the study followed by feeding 2 L/dmilk from d 46 to 56 of the study), and (3) SUSD (6L/d milk from d 1 to 5, 8 L/d milk from d 6 to 15, 10L/d milk from d 16 to 35, 8 L/d milk from d 36 to 42,6 L/d milk from d 43 to 47, 4 L/d milk from d 48 to52 of the study followed by feeding 2 L/d milk from d53 to 56 of the study). Calves were weaned on d 56 andfollowed until d 70 of the study period. Animals hadad libitum access to the same starter ration during theentire study period (d 3 to 70). Starter intake, totaldry matter intake, and average daily gain were greaterin the SUSD calves than those in the CONV and STPtreatments during the preweaning period. The SUSDprocedure was found to increase body weight duringthe entire study and improved body length, witherheight, heart girth, hip height, and hip width on d 56and 70 of the study compared with the STP and CONVcalves. The SUSD treatment increased blood glucoseconcentration on d 35 compared with CONV and STPprocedures. The STP group had a higher and BHBA than did the SUSD animals duringthe preweaning period. Neither the SUSD nor the STPprocedure negatively affected the fecal score. In conclusion,the SUSD milk feeding procedure was found toimprove the performance of dairy calves compared withthe STP and CONV procedures. However, it appearsthat the STP procedure induces earlier reticulo-rumendevelopement in dairy calves than does the SUSD procedure.starter intakethan the CONV and SUSD animals. The STP animals
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