Research on metabolizable energy level and crude protein content in total mixed rationfor F1 crossbreeds (BBB x lai Sind) in the period from 6 to 12 months of age
An experiment was conducted to determine the metabolizable energy (ME) level and crude protein content in the total mixed ration (TMR) for F1 crossbreed (BBB ´ lai Sind) in the period from 6 to 12 months of age. Three levels of ME and crude protein in the TMR were tested as follows: ME of 9.5 MJ/kg DM and crude protein 13% (as DM) (Group1); ME of 10 MJ/kg DM and crude protein was 14.0% (as DM) (Group2); ME of 10.5 MJ/kg DM and crude protein was 15% (as DM) (Group3). Eighteen calves (male/female ratio of 50/50) from 6 to 12 months old with equivalent body weight to each experimental group were divided into three experimental groups. The experiment was designed randomly. TMR ingredients were mixed before each feeding, fodder was chopped before mixing. Calves were given two meals a day, free drinks.Experimental results showed that the average weight gain of the group with a crude protein ratio of 15.0% was 926.9 g/head/day, while that of the group with a crude protein ratio was 14% and 13% reached 923.1 and 863.9 g/head/day. Increasing density of ME and protein level in the diet reduced the amount of DM intake of cattle at 5 of 6 months of experiment (P<0.05). The cost of feed for 1kg ofweight increased was highest at a diet with a ME density of 9.5 MJ/kg DM, 13% crude protein, followed by a diet with a ME density of 10.5 MJ/kgDM, crude protein 15%, and lowest at a density of ME 10 MJ/kg DM, crude protein 14%.
