Effect of feeding total mixed ration with ad libitum or restricted pelleted starter on growth performance, rumination behaviour, blood metabolites and rumen fermentation of Holstein calves

Abstract

Abstract The objective of this study was to evaluate the effects of diet with ad libitum TMR and restricted starter on animal performance, rumination time, blood metabolites and rumen fermentation of Holstein calves during the pre- and post-weaning periods. Thirty female Holstein calves were randomly assigned at birth (38.5 ± 1.96 kg) to receive 3 treatments. Calves, from 21 days of age, were fed 1 of 3 treatments as follows: Control diet (CTR) with TMR and starter ad libitum; Treatment 1 diet (TRT1) with TMR and starter ad libitum; Treatment 2 diet (TRT2) with ad libitum TMR and restricted amount of calf starter (50% of the intake recorder in the control group day by day. The results showed that the reduced amount of starter did not compromise the growth of calves nor did it compromise the ruminal and metabolic parameters of the animals. The inclusion of ad libitum TMR indeed, improved the rumination time especially after weaning. Overall, the results indicated that the calf starter can be partially replaced with a TMR in weaning calves, reducing the feeding costs of weaning dairy calves.