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چکیده
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Performance of female Holstein calves (n = 60) were evaluated in three step-down milk feeding programmes: step-down 1 (STP1: 7.5 litres/day milk from days 1 to 21, 6 litres/day milk from days 22 to 42, 4 litres/day milk from days 43 to 63 and 2 litres/day milk from days 64 to 84 of the study); step-down 2 (STP2; 7.5 litres/day milk from days 1 to 21, 6 litres/day milk from days 22 to 42 and 2 litres/day milk from days 43 to 63 of the study); and step-down 3 (STP3; 7.5 litres/day milk from days 1 to 21, 4 litres/day milk from days 22 to 42 and 2 litres/day milk from days 43 to 63 of the study). Intakes of starter were monitored daily and body weight (BW), average daily gain (ADG) and wither height (WH) were measured monthly. Calves in STP3 had lower dry matter intake between 22 and 42 days than STP2 animals, but starter intake was greater in STP2 and STP3 calves than those in the STP1 treatment between 43–63 and 64–84 days. Total ADG was greater in STP2 and STP3 animals than in STP1 calves. No effect of treatment was observed on breeding age, BW, WH or service per conception. In addition, conception rate at first breeding was not influenced by treatment. It was concluded that the STP2 and STP3 milk feeding regimes improved performance in calves and there was no benefit in feeding milk for longer than 63 days in terms of breeding outcomes.
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