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چکیده
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The potential effect of dietary forage supplementation on the performance and rumen development in dairycalves is well established. However, limited research has been directed to the comparative effects of forage offeringmethods on calf performance. The objective of the present study was to determine the effects of forage provisionmethods (total mixed ration or free choice) on the performance, nutrient digestibility, rumen fermentationand nutritional behaviour in newborn calves. Forty-five Holstein dairy calves (3 days of age and 41 2 kg ofbody weight) were assigned to the following three groups (n = 15): (i) starter without forage provision (CON),(ii) starter supplemented with 10% alfalfa hay (AH) as a total mixed ration (AH-TMR) and (iii) starter and AH asa free-choice provision (AH-FC) for a period of 70 days. All the calves were offered 5 l of milk/day from day 3 to50, and 2.5 l/day from day 50 until weaning on day 56. Dry matter intake (DMI) was greater (p < 0.01) in theAH-TMR and AH-FC treatments than in the CON during the pre- and post-weaning periods. Calves fed theAH-FC diet showed the highest post-weaning DMI among the treatments. The calves receiving ad libitum foragetended (p = 0.08) to increase crude protein digestibility and overall volatile fatty acids (VFA) concentrations inthe rumen. No differences were observed among the treatments at the time spent on standing, lying, eating andperforming non-nutritive oral behaviours. Compared to CON calves, animals in the AH-TMR treatment spentmore time (p < 0.05) ruminating. In conclusion, our data suggest that forage supplementation in both forageoffering methods increased total DMI, ruminal pH and ruminating time in dairy calves. Hence, there is no benefitin the free-choice provision of AH in dairy calves.
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