Pre- and post weaning performance and health of calves fed texturized calf starters with different additives during the nursery phase

Abstract Text: One-hundred-thirty-one (2-4 d old) individually fed Holstein heifer calves (39.3 ± 0.66 kg) were randomly assigned to 1 of 5 treatments to evaluate pre- (d 1-42) and post weaning (d 43-56) calf performance and health when fed 18% CP (as-fed) texturized calf starters (CS) with different additives. All calves were fed a non-medicated 20% fat:20% protein milk replacer at 0.284 kg in 1.99 L water (12.5% solids) 2X daily for the first 35 d and 1X daily from d 36 to weaning at 42 d. During the first 14 days of the study, neomycin (1600 g/ton) and oxytetracycline (1600 g/ton) were mixed with the milk replacer to provide 22 mg/kg BW daily to each calf to control diarrhea during  this period.     Calf starters were fed free choice from d 1 and calves had access to fresh water. The additives in the CS included:1), none (N); 2), decoquinate (DQ) at 49.9mg/kg; 3), monensin (M) at 44 mg/kg; 4), lasalocid (L) at 96.8 mg/kg; and 5), bambermycin (B) at 44  mg/kg. Data were analyzed using PROC Mixed procedures of SAS and repeated measures. There were no CS gain affects during d 1 to 14 when CS intake was low. Calves fed B had the highest ADG (P < 0.05), d 15 to 28. From d 29 to 42 calves fed CS with  B, L, and DQ had higher ADG (P < 0.05) than those fed M but similar to N calves. Overall pre-weaning daily gains were similar across CS treatments (P > 0.05). Pre-weaning CS intakes were higher for calves fed B vs. those fed N and M. This reflected ADG  differences in the interim weigh periods. Daily gains post-weaning and overall were the  lowest for calves fed M (P < 0.05). Calves fed B had higher ADG  (P < 0.05) for d 1 to 56 vs. N calves. Total d 1 to 56 DMI was the lowest (P < 0.05) for calves fed M. Gain/feed was not affected by CS fed. Average daily gains for the 56 d study were  0.75, 0.78, 0.69, 0.76 and 0.81 kg for calves fed N, DQ, M, L, and B, respectively. There were no health differences across treatments (P > 0.05). Under the conditions of this study, calves fed M had the lowest overall performance. Calves fed DQ, L and B performed similarly.

Keywords: Calf performance, calf starters, additives