The aims of the present experiment were: 1) to evaluate the effects of enhanced feeding programs and trace minerals source early in life on growth and health of transported calves, and 2) to quantify the effect of early nutrition programs and trace minerals source on hoof tissue development in young transported calves.Ninety Holstein bull calves <1 wk old were assigned to treatments in a 2 x 2 factorial arrangement of plane of nutrition (PN) and trace minerals source (TM) in a randomized, complete-block design. Conventional PN received milk replacer (22% CP, 20% fat; 568 g/d powder for wk 1 to 4, 284 g/d powder for wk 5) plus ad libitum starter mix (18% CP, DM basis, forwk 1 to 12) and hay (0.5 kg/d as fed, for wk 10 to 12) and were weaned at 6 wk.During wk 13 to 20 calves were fed 3.2 kg/d of grower mix (16% CP, DM basis) plus chopped hay ad libitum. Accelerated PN received variable amounts of milk replacer (28% CP, 20% fat; 810, 1136, and 568 g/d of powder for wk 1, 2 to 6, and 7 respectively) plus ad libitum starter mix (22% CP, DM basis wk 1 to 12) and limited hay (0.5 kg/d as fed, for wk 10 to 12) and were weaned at wk 7. Ad libitum grower plus limited chopped hay (0.5 kg/g, as-fed basis) was offered from wk 13 to 20. Milk replacer was formulated to contain balanced amounts of either inorganic or organic TM (50, 50, 10, and 100 ppm of Zn, Mn, Cu, and Fe, respectively).Accelerated PN treatments increased overall growth, average daily gain (ADG), and gain to feed (G:F) through wk 20. Organic TM increased growth when supplemented to accelerated PN but not when supplemented to the conventional programs. Therefore, a synergistic effect was observed between accelerated PN and organic TM by means of increasing the biological value of each other.iiCalves are born with uneven claw lengths; rear medial claws were longer than front and lateral claws. Organic TM increased claw length after wk 10 in comparison to inorganic TM, and in the same way, organic TM increased groove length when fed in enhanced nutritional programs but not in conventional. These effects might be associated with an accumulative effect of organic TM supplementation.Enhanced PN programs had a greater effect in increasing overall hoof growth; in contrast, organic TM had a greater effect on reducing overall hoof wear.Results indicated that enhanced nutritional programs during early life will allow calves to have greater overall growth and maintain a normal health status throughout the preweaning period. Accelerated nutritional programs promoted a greater effect of organic TM on hoof growth, while organic TM to decreased overall hoof wear compared with inorganic sources.
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Effect of source of trace minerals and plane of nutrition on growth and health performance and hoof development of transported dairy calves