Effects of Substitution of Maize with Dried Orange Pulp on Performance and Blood Metabolites of Male Calves

The aim of the study was to assess the effect of substitution of maize with dried orange pulp on performance and some blood parameters of young Holstein male calves. Twenty Holstein male calves (3 days old and average body weight 42.3 +/- 3.6 kg were assigned to two treatment groups. The orange pulp was dried at 80 degrees C with hot air application in the band dryer system. The first group was fed calf starter including 10% dried orange pulp (DOP) and the second treatment group was fed calf starter without dried orange pulp (Control = CNT) during the treatment. Calf starters were formulated to contain average 21% crude protein, 3.4% crude fat and 2600 kcal/kg metabolic energy (DM basis). Calves were weaned after 8 weeks then all calves were fed a total mixed diet containing 50% alfalfa hay and 50% calf starter for another three weeks. Feed intake and body weight gain were recorded weekly and individual blood samples were collected once in two weeks. The results showed that there was no significant difference (P > 0.05) between the groups in terms of feed consumption, body weight gain and metabolites as glucose, cholesterol, none esterified fatty acids, beta-hydroxybutyric acid and IGF-1 levels in serum. However, there was a significant difference between the groups in terms of IGF-1 (P<0.05). Those results showed that maize could be substituted with dried orange pulp in calf starters.